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Intraoperative Neurophysiologic Monitoring

Policy Number: MP-306

 

Latest Review Date: May 2019

Category:  Medical                                                                

Policy Grade:  B

Description of Procedure or Service:

Intraoperative neurophysiologic monitoring (IONM) describes a variety of procedures used to monitor the integrity of neural pathways during high-risk neurosurgical, orthopedic, and vascular surgeries. It involves the detection of electrical signals produced by the nervous system in response to sensory or electrical stimuli to provide information about the functional integrity of neuronal structures. This evidence review does not address established neurophysiologic monitoring (i.e., somatosensory-evoked potentials, motor-evoked potentials using transcranial electrical stimulation, brainstem auditory-evoked potentials, electromyography of cranial nerves, electroencephalography, electrocorticography), during spinal, intracranial, or vascular procedures.

Intraoperative Neurophysiologic Monitoring

The principal goal of intra-operative monitoring is the identification of the nervous system impairment in the hope that prompt intervention will prevent permanent deficits. Correctable factors at surgery include circulatory disturbance, excess compression from retraction, bony structures, or hematomas, or mechanical stretching. The technology is continuously evolving with refinements in equipment and analytic techniques including multimodal intraoperative monitoring in which more than one technique is used and recording in which several patients are monitored under the supervision of a physician who is outside the operating room.

The different methodologies of monitoring are described below:

Sensory-Evoked Potentials

Sensory-evoked potential describes the responses of the sensory pathways to sensory or electrical stimuli. Intra-operative monitoring of sensory-evoked potentials is used to assess the functional integrity of central nervous system (CNS) pathways during operations that put the spinal cord or brain at risk for significant ischemia or traumatic injury. The basic principles of sensory-evoked potential monitoring involve identification of a neurological region at risk, selection and stimulation of a nerve that carries a signal through the at-risk region, and recording and interpretation of the signal at certain standardized points along the pathway. Monitoring of sensory-evoked potentials is commonly used during the following procedures: carotid endarterectomy, brain surgery involving vasculature, surgery with distraction compression or ischemia of the spinal cord and brainstem, and acoustic neuroma surgery. Sensory evoked potentials can be further broken down into the following categories according to the type of stimulation used:

  • Somatosensory-evoked potentials (SSEPs) are cortical responses elicited by peripheral nerve stimulations. Peripheral nerves, such as the median, ulnar, or tibial nerve are typically stimulated, but in some situations the spinal cord may be stimulated directly. Recording is done either cortically or at the level of the spinal cord above the surgical procedure. Intra-operative monitoring of SSEPs is most commonly used during orthopedic or neurologic surgery to prompt intervention to reduce surgically induced morbidity and/or to monitor the level of anesthesia. One of the most common indications for SSEP monitoring is in patients undergoing corrective surgery for scoliosis. In this setting, SSEP monitors the status of the posterior column pathways, and thus does not reflect ischemia in the anterior (motor) pathways. Several different techniques are commonly used, including stimulation of a relevant peripheral nerve with monitoring from the scalp, from interspinous ligament needle electrodes, or from catheter electrodes in the epidural space.

  • Brainstem auditory-evoked potentials (BAEPs) are generated in response to auditory clicks and can define the functional status of the auditory nerve. Surgical resection of a cerebellopontine angle tumor, such as an acoustic neuroma, places the auditory nerves at risk, and BAEPs have been extensively used to monitor auditory function during these procedures.

  • Visual-evoked potentials (VEPs) are used to track visual signals from the retina to the occipital cortex light flashes. VEP monitoring has been used for surgery on lesions near the optic chiasm. However, VEPs are very difficult to interpret due to their sensitivity to anesthesia, temperature, and blood pressure.

Motor-Evoked Potential Monitoring

Motor-evoked potentials are recorded from muscles following direct or transcranial electrical stimulation of motor cortex or by pulsed magnetic stimulation provided by a coil placed over the head. Stimulation induces an electrical current in the brain or spinal cord which in turn can stimulate the motor neurons. Muscle activity is recorded by electrodes placed on the skin at prescribed points along the motor pathways. Motor evoked potentials, especially when induced by magnetic stimulation, can be affected by anesthesia. The Digitimer electrical cortical stimulator received U.S. Food and Drug Administration (FDA) premarket approval in 2002. Devices for transcranial magnetic stimulation have not been approved by FDA for this use.

Multimodal IONM, in which more than 1 technique is used, most commonly with SSEPs and MEPs, has also been described.

Electromyogram (EMG) Monitoring and Nerve Conduction Velocity Measurements

Electromyogram (EMG) monitoring and nerve conduction velocity measurements can be performed in the operating room and may be used to assess the status of the cranial or peripheral nerves, e.g., to identify the extent of nerve damage prior to nerve grafting or during resection of tumors. ). For procedures with a risk of vocal cord paralysis due to damage to the recurrent laryngeal nerve (i.e., during carotid artery, thyroid, parathyroid, goiter, or anterior cervical spine procedures), monitoring of the vocal cords or vocal cord muscles has been performed. In addition, these techniques may be used during procedures around the nerve roots and around peripheral nerves to assess the presence of excessive traction or other impairment. Surgery in the region of cranial nerves can be monitored by electrically stimulating the proximal (brain) end of the nerve and recording via EMG in the facial or neck muscles. Thus, monitoring is done in the direction opposite that of sensory-evoked potentials, but the purpose is similar to verify that the neural pathway is intact.

EEG (Electroencephalogram) Monitoring

Spontaneous electroencephalogram (EEG) monitoring can also be recorded during surgery and can be subdivided as follows:

  • EEG monitoring has been widely used to monitor cerebral ischemia secondary to carotid cross clamping during a carotid endarterectomy. EEG monitoring may identify those patients who would benefit from the use of a vascular shunt during the procedure to restore adequate cerebral perfusion. Conversely, shunts, which have an associated risk of iatrogenic complications, may be avoided in those patients in whom the EEG is normal. Carotid endarterectomy may be done with the patient under local anesthesia so that monitoring of cortical function can be directly assessed.

  • Electrocorticography (Cog) is the recording of the EEG directly from a surgically exposed cerebral cortex. Cog is typically used to define the sensory cortex and to map the critical limits of a surgical resection. ECoG recordings have been most frequently used to identify epileptogenic regions for resection. In these applications, electrocorticography does not constitute monitoring per se.

Intraoperative neurophysiologic monitoring, including SSEPs and MEPs using transcranial electrical stimulation, BAEPs, EMG of cranial nerves, EEG, and ECoG, has broad acceptance, particularly for spine surgery and open abdominal aorta aneurysm repairs. These indications have long been considered standard of care, as evidenced by numerous society guidelines, including those from the American Academy of Neurology, American Clinical Neurophysiology Society, American Association of Neurological Surgeons, Congress of Neurologic Surgeons, and American Association of Neuromuscular & Electrodiagnostic Medicine. Therefore, this evidence review focuses on monitoring of the recurrent laryngeal nerve during neck and esophageal surgeries and monitoring of peripheral nerves.

Policy:

Effective for dates of service on and after May 13, 2019:

Intraoperative neurophysiologic monitoring, which includes somatosensory-evoked potentials, motor-evoked potentials using transcranial electrical stimulation, brainstem auditory-evoked potentials, EMG of cranial nerves, EEG, and electrocorticography (ECoG), may be considered medically necessary during spinal, intracranial, vascular procedures or follows individual criteria for specific procedures* listed below when all of the following criteria are met:

  1. There is clinical data in the medical record to support the medical necessity of ordering the test.  The data could include radiological, neurological, consultative notes, or physical exam documentation; and

  2. A licensed physician other than the operating surgeon or performing anesthesiologist must monitor the procedure and the monitoring physician must be on the premises and available to be in the operating room; and

* Individual criteria for specific procedures for Intraoperative neurophysiologic monitoring:

  • Recurrent laryngeal nerve may be considered medically necessary in patients undergoing high-risk thyroid or parathyroid surgery, including:

    • total thyroidectomy

    • repeat thyroid or parathyroid surgery

    • surgery for cancer

    • thyrotoxicosis

    • retrosternal or giant goiter

    • thyroiditis

  • Anterior cervical spine surgery associated with any of the following increased risk situations:

    • prior anterior cervical surgery, particularly revision anterior cervical discectomy and fusion, revision surgery through a scarred surgical field, reoperation for pseudarthrosis or revision for failed fusion

    • multilevel anterior cervical discectomy and fusion

    • pre-existing recurrent laryngeal nerve pathology, when there is residual function of the recurrent laryngeal nerve.

Intraoperative neurophysiologic monitoring of the recurrent laryngeal nerve during anterior cervical spine surgery not meeting the criteria above or during esophageal surgeries is considered not medically necessary and investigational.

Intraoperative monitoring of visual-evoked potentials is considered not medically necessary and investigational.

Intraoperative monitoring of motor-evoked potentials using transcranial magnetic stimulation is considered not medically necessary and investigational.

Intraoperative EMG and nerve conduction velocity monitoring during surgery on the peripheral nerves is considered not medically necessary.

Effective for dates of service prior to May 13, 2019:

Intraoperative monitoring, which includes somatosensory-evoked potentials, motor-evoked potentials using transcranial electrical stimulation, brainstem auditory-evoked potentials, EMG of cranial nerves, EEG, and electrocorticography (ECoG), may be considered medically necessary during spinal, intracranial, or vascular procedures when all the following criteria are met:

  1. There is clinical data in the medical record to support the medical necessity of ordering the test.  The data could include radiological, neurological, consultative notes, or physical exam documentation; and

  2. A licensed physician other than the operating surgeon or performing anesthesiologist must monitor the procedure and the monitoring physician must be on the premises and available to be in the operating room; and

  3. The monitoring physician interprets no more than three cases concurrently. 

Intraoperative neurophysiologic monitoring of the recurrent laryngeal nerve may be considered medically necessary in patients undergoing:

  • high-risk thyroid or parathyroid surgery, including:

    • total thyroidectomy

    • repeat thyroid or parathyroid surgery

    • surgery for cancer

    • thyrotoxicosis

    • retrosternal or giant goiter

    • thyroiditis

  • anterior cervical spine surgery associated with any of the following increased risk situations:

    • prior anterior cervical surgery, particularly revision anterior cervical discectomy and fusion, revision surgery through a scarred surgical field, reoperation for pseudarthrosis or revision for failed fusion

    • multilevel anterior cervical discectomy and fusion

    • pre-existing recurrent laryngeal nerve pathology, when there is residual function of the recurrent laryngeal nerve.

Intraoperative neurophysiologic monitoring of the recurrent laryngeal nerve during anterior cervical spine surgery not meeting the criteria above or during esophageal surgeries is considered not medically necessary and investigational.

Intraoperative monitoring of visual-evoked potentials is considered not medically necessary and investigational.

Intraoperative monitoring of motor-evoked potentials using transcranial magnetic stimulation is considered not medically necessary and investigational.

Intraoperative EMG and nerve conduction velocity monitoring during surgery on the peripheral nerves is considered not medically necessary.

Note: These policy statements refer only to use of these techniques as part of intraoperative monitoring. Other clinical applications of these techniques, such as visual-evoked potentials and EMG, are not considered in this policy.

Key Points:

The most recent literature update was performed through February 18, 2019. Following is a summary of the key literature to date.

Early literature focused on intraoperative monitoring of cranial and spinal nerves. This evidence review focuses on more recently investigated techniques, including monitoring of the recurrent laryngeal nerve (RLN) and peripheral nerves.

The clinical evidence to determine whether the use of technology improves the net health outcome is assessed by evidence reviews. Health outcomes are assessed by the length of life, quality of life, and ability to function, including benefits and harms. Every clinical condition has specific outcomes that are important to patients and managing the course of that condition. Outcome measures are validated to ascertain whether a condition improves or worsens; and whether the magnitude of that change is clinically significant. The net health outcome is a balance of benefits and harms.

The net health outcome of technology is assessed by whether the evidence is sufficient enough to draw conclusions, while examining two domains: the relevance, and quality and credibility. To be relevant, studies must represent one or more intended clinical use of the technology in the intended population and compare an effective and appropriate alternative at a comparable intensity. In various conditions, the alternative will be supportive care or surveillance. The quality and credibility of the evidence is determined by study design and conduct, minimizing bias and confounding that can generate incorrect findings. The randomized controlled trial (RCT) is favored to assess efficacy; however, in some circumstances, nonrandomized studies may be adequate. RCTs are rarely large enough or long enough to capture less common adverse events and long-term effects. Other types of studies can be used for these purposes and to assess generalizability to broader clinical populations and settings of clinical practice.

Intraoperative Neurophysiologic Monitoring of the RLN during Thyroid or Parathyroid surgery

Clinical Context and Therapy Purpose

The purpose of intraoperative neurophysiologic monitoring is to provide a treatment option that is an alternative to or an improvement on existing therapies, such as surgery without

neurophysiologic monitoring, in patients who are undergoing thyroid or parathyroid surgery and are at high risk of injury to the recurrent laryngeal nerve.

The question addressed in this evidence review is: Will neurophysiologic monitoring improve the net health outcomes in patients undergoing surgeries that could damage their recurrent

laryngeal nerve or peripheral nerves?

The following PICOTS were used to select literature to inform this review.

Patients

The patient population of interest are individuals who are undergoing thyroid or parathyroid surgery and are at high risk of injury to the recurrent laryngeal nerve.

Interventions

The therapy being considered is intraoperative neurophysiologic monitoring.

Intraoperative neurophysiologic monitoring (IONM) describes a variety of procedures used to monitor the integrity of neural pathways during high-risk neurosurgical, orthopedic, and

vascular surgeries. It involves the detection of electrical signals produced by the nervous system in response to sensory or electrical stimuli to provide information about the functional

integrity of neuronal structures.

Comparators

Comparators of interest include surgery without neurophysiologic monitoring. This operation is managed by endocrine surgeons and primary care providers in an outpatient surgical

setting.

Outcomes

The outcomes of interest are morbid events, functional outcomes, and quality of life.

Timing

The existing literature evaluating intraoperative neurophysiologic monitoring as a treatment for patients who are undergoing thyroid or parathyroid surgery and are at high risk of injury

to the recurrent laryngeal nerve has varying lengths of follow up. However, extended follow up is necessary to fully observe outcomes.

Setting

Patients who are undergoing thyroid or parathyroid surgery and are at high risk of injury to the recurrent laryngeal nerve are actively managed by endocrine surgeons, neurosurgeons, and

primary care providers in an outpatient surgical setting.

Study Selection Criteria

Methodologically credible studies were selected using the following principles:

a. To assess efficacy outcomes, comparative controlled prospective trials were sought, with a preference for RCTs;

b. In the absence of such trials, comparative observational studies were sought, with a preference for prospective studies.

c. To assess longer term outcomes and adverse events, single-arm studies that capture longer periods of follow-up and/or larger populations were sought.

Studies with duplicative or overlapping populations were excluded.

In 2016, Pardal-Refoyo and Ochoa-Sangrador reported on a systematic review of RLN injury during total thyroidectomy with or without intraoperative neurophysiologic monitoring (IONM). Included were 1 large (n=1000) and 1 small (n=23) RCT and 52 case series (total N=30,922 patients) that estimated the risk to the RLN. Twenty-nine studies used RLN monitoring and 25 did not. The prevalence of bilateral laryngeal paralysis in patients who had RLN monitoring was lower (2.43%; 95% confidence interval [CI], 1.55% to 3.5%) compared to series that did not (5.18%; 95% CI 2.53 to 8.7%). The absolute risk reduction was 2.75%, with a number needed to treat of 364.13.

The largest RCT of RLN neuromonitoring for thyroid surgery was reported by Barczynski et al in 2009. RLN monitoring was performed with electrodes on the vocal muscles through the cricothyroid ligament, which may not be the method currently used in the United States. In 500 patients who had thyroidectomy with only visual RLN identification, there were 38 cases of transient RLN injuries and 12 cases of permanent RLN injuries. In the 500 patients who had visualization plus RLN monitoring, there were 19 transient injuries and 8 permanent RLN injuries. The absolute risk reduction with the addition of RLN monitoring was 2.3% for RLN injury (p=0.007) and 1.9% for RLN paresis (p=0.011), with no significant difference in the prevalence of permanent RLN palsy (0.4%, p=NS). However, in high-risk patients, defined as those undergoing surgery for cancer, thyrotoxicosis, retrosternal or giant goiter, or thyroiditis, the prevalence of transient RLN paresis was 2.9% lower in in patients who had RLN monitoring (p=0.011) compared to those with visual identification only. In low-risk patients, there was no significant difference in RLN injury rates between monitoring and no monitoring. Notably, high-risk patients with prior thyroid or parathyroid surgery were excluded from this trial. A benefit of RLN monitoring was also shown in patients undergoing high-risk total thyroidectomy.

Henry et al (2017) reported on a systematic review of meta-analyses published up to February 2017 that compared intraoperative neurophysiologic monitoring (IONM) with direct RLN visualization by assessing rates of vocal fold palsy. Reviewers included 8 meta-analyses of RCTs or observational studies (prospective or retrospective) and selected the best evidence, based on the Jadad algorithm. The 8 meta-analyses differed significantly in the literature search methodology, databases included, the inclusion of quality assessment, and most did not include a study quality assessment. Using the Jadad algorithm, reviewers determined the meta-analysis by Pisanu et al (2014)9 to have the highest quality; it found that concluded no statistically significant reductions in RLN injury between procedures using IONM vs direct RLN visualization. However, reviewers also noted that recent developments in IONM technology such as continuous vagal IONM and staged thyroidectomy might provide additional benefits, which were out of the scope of their systematic review and need to be assessed in further assessment in prospective multicenter trials.

Sun et al (2017) reported on a meta-analysis of RLN injury during thyroid surgery with or without IONM. Included were 2 prospective cohort studies and 7 retrospective cohort studies. Results are summarized in Tables 1 and 2. The absolute risk reduction was 2.75%, with a number needed to treat of 364.13. Observed differences in the subgroup analysis were very imprecise because the number of observed paralyses was very low. IONM was associated with a reduction in overall and permanent RLN palsy in thyroid reoperations. Limitations included small sample sizes and study heterogeneity.

Table 1. Characteristics of Systematic Reviews

Study

Dates

Trials

Participants

N (Range)

Design

Duration

Pardal-Refoyo and Ochoa-Sangrador (2016)

1987-2013

  • 2 RCTs

  • 52 case series

Studies reporting incidence of RLN paralysis after

single-stage

30,922

  • RCT

  • Case series

NR

Sun et al (2017)

Up to Aug 2016

9

Studies reporting incidence of RLN complications after thyroid surgery

2436 nerves at risk (1109 with IONM, 1327 without IONM)

Prospective/ retrospective cohort studies

NR

Henry et al (2017)

Up to Feb 2017

8 meta-analyses

Meta-analyses of RCTs and non-RCTs comparing IONM with direct visualization for RLNs during thyroidectomy

8 meta-analyses (range, 6-23 patients)

Meta-analysis

NR

Table 2. Results of Systematic Reviews

Study

Risk of Bilateral RLN Paralysis

Transient RLN Palsy

Permanent RLN Palsy

Pardal-Refoyo and Ochoa-Sangrador (2016)

ARR (95% CI)

2.75% (NR)a

NNT (95% CI)

364 (NR)a

I2 (p)

8%a

Overall RLN Palsy

Sun et al (2017)

With IONM

4.69%

3.98%b

1.26%b

Without IONM

9.27%

6.63%b

2.78%b

RR (95% CI) (p)

0.434 (0.206 to 0.916) (0.029)

0.607 (0.270 to 1.366) (0.227)b

0.426 (0.196 to 0.925) (0.031)b

NNT (95% CI)

NR

NRb

NRb

I2 (p)

70.2%

67.4%b

13.7%b

ARR: absolute risk reduction; CI: confidence interval; IONM: intraoperative neurophysiologic monitoring NNT: number needed to treat; NR: not reported; RLN: recurrent laryngeal nerve; RR: relative risk.

a Sample size of 11,947 patients.

b Sample of 7 studies.

Table 3. Summary of Key Trial Characteristics

Study

Countries

Sites

Dates

Participants

Active

Comparator

Barczynski et al (2009)

Poland

1

2006-2007

Patients undergoing bilateral neck surgery

500

500

Table 4. Summary of Key RCT Results

Study

RLN Injury

RLN Paresis

Permanent RLN Palsy

Barczynski et al (2009)

RLN visualization alone, n/N

8/500

NR

NR

RLN visualization plus monitoring, n/N

NR

NR

NR

ARR (95% CI) (p)

2.3% (NR) (0.007)

1.9% (NR) (0.011)

0.4% (NR) (NS)

NNT (95% CI)

NR

NR

NR

Section Summary: Intraoperative Neurophysiologic Monitoring of the RLN during Thyroid or Parathyroid Surgery

The evidence on the use of IONM in reducing RLN injury includes a large RCT and systematic reviews on thyroid and parathyroid surgery. The strongest evidence derives from an RCT of 1000 patients undergoing thyroid surgery. This RCT found minimal effect of IONM overall, but a significant reduction in RLN injury in patients at high risk for injury. High risk in this trial was defined as surgery for cancer, thyrotoxicosis, retrosternal or giant goiter, or thyroiditis. The high-risk category may also include patients with prior thyroid or parathyroid surgery or total thyroidectomy.

IONM of the RLN during Cervical Spine Surgery

Clinical Context and Therapy Purpose

The purpose of intraoperative neurophysiologic monitoring is to provide a treatment option that is an alternative to or an improvement on existing therapies, such as surgery without

neurophysiologic monitoring, in patients who are undergoing anterior cervical spine surgery and are at high risk of injury to the recurrent laryngeal nerve.

The question addressed in this evidence review is: In patients undergoing surgeries that could damage their recurrent laryngeal nerve or peripheral nerves, does neurophysiologic monitoring improve the net health outcomes?

The following PICOTS were used to select literature to inform this review.

Patients

The patient population of interest are individuals who are undergoing anterior cervical spine surgery and are at high risk of injury to the recurrent laryngeal nerve.

Interventions

The therapy being considered is intraoperative neurophysiologic monitoring.

Intraoperative neurophysiologic monitoring (IONM) describes a variety of procedures used to monitor the integrity of neural pathways during high-risk neurosurgical, orthopedic, and

vascular surgeries. It involves the detection of electrical signals produced by the nervous system in response to sensory or electrical stimuli to provide information about the functional

integrity of neuronal structures.

Comparators

Comparators of interest include surgery without neurophysiologic monitoring. This operation is managed by neurosurgeons, orthopedic surgeons, and primary care providers in an

inpatient surgical setting.

Outcomes

The outcomes of interest are morbid events, functional outcomes, and quality of life.

Timing

The existing literature evaluating intraoperative neurophysiologic monitoring as a treatment for patients who are undergoing anterior cervical spine surgery and are at high risk of injury

to the recurrent laryngeal nerve has varying lengths of follow up. While studies described below all reported at least one outcome of interest, longer follow-up was necessary to fully

observe outcomes.

Setting

Patients who are undergoing anterior cervical spine surgery and are at high risk of injury to the recurrent laryngeal nerve are actively managed by neurosurgeons, orthopedic surgeons,

and primary care providers in an inpatient surgical setting.

Study Selection Criteria

Methodologically credible studies were selected using the following principles:

a. To assess efficacy outcomes, comparative controlled prospective trials were sought, with a preference for RCTs;

b. In the absence of such trials, comparative observational studies were sought, with a preference for prospective studies.

c. To assess longer term outcomes and adverse events, single-arm studies that capture longer periods of follow-up and/or larger populations were sought.

Studies with overlapping populations were excluded.

Ajiboye et al (2017) reported on the results of a systematic review that included 10 studies (total N= 26,357 patients). All studies were of low methodologic quality but had a low risk of bias. Only studies compared the risk of nerve injury using IONM with no IONM. Based on data from these 2 studies, there was no statistically significant difference in the risk of neurologic injury with or without IONM (odds ratio, 0.726; 95% confidence interval [CI], 0.287 to 1.833; p=0.498) (see Tables 5 and 6).

Erwood et al (2016) reported on the results of a meta-analysis that summarized the relative rate of RLN injury following revision anterior cervical discectomy and fusion. The meta-analysis did not report RLN injury rate with IONM vs without IONM. Based on pooled data from 3 prospective cohort studies and 5 retrospective series (total N=238 patients), reviewers reported an overall RLN injury rate of 14.1% (95% CI, 9.8% to 19.1%)  (see Tables 5 and 6).

In 2018, Daniel et al published a literature review and meta-analysis assessing intraoperative neurophysiological monitoring (IONM) during spinal operative surgical procedures. Six retrospective studies, published between 2006 and 2016, with a total of 335,458 patients (range, 74–231,067) were included. Pooled OR for neurological events with and without IONM was 0.72 (95% CI: 0.71–1.79; p=0.4584), and sensitivity analysis, which included only two studies, had a pooled OR of 0.199 (95% CI 0.038–1.035; p=0.055). The review was limited by the lack of prospective studies, minimal high methodological quality assessments, and the inclusion of various spinal procedures with different rates of neurological events.

Table 5. Systematic Review Characteristics

Study

Dates

Trials

Participants

N (Range)

Design

Duration

Ajiboye et al (2017)

NR

10

Studies reporting IONM use for ACSS

26,357 (16-22,768)

  • 9 retrospective

  • 1 prospective

NR

Erwood et al (2016)

1998-2015

8

Studies reporting reoperative ACSS for RLN

238 (13-63)

  • 5 prospective

  • 3 retrospective

2 wk to 24 mo

Daniel et al (2018)

2006-2016

6

Studies reporting IONM use for spinal surgical procedures

335,458 (74-

231,067)

2 cohort

4 retrospective

NR

ACSS: anterior cervical spine surgery; IONM: intraoperative neurophysiologic monitoring; NR: not reported; RLN: recurrent laryngeal nerve.

Table 6. Systematic Review Results

Study

Risk of Neurologic Injury

Ajiboye et al (2017)

OR (95% CI) (p)a

0.726 (0.287 to 1.833) (0.44)b

NNT (95% CI)

NR

I2 (p)

0% (NR)

Erwood et al (2016)

Estimate (95% CI) (p)a

0.14 (0.10 to 0.19)

NNT (95% CI)

NR

I2 (p)

10.7% (NR)

Daniel et al (2018)

OR (95% CI) (p)

0.72 (0.71 to 1.79) (0.4584)

CI: confidence interval; NNT: number needed to treat; NR: not reported; OR: odds ratio.

a Risk of neurologic injury after anterior cervical discectomy and fusion with or without intraoperative neurophysiologic monitoring.

b Included 2 studies.

Section Summary: IONM of the RLN during Cervical Spine Surgery

The evidence on the use of IONM in reducing RLN injury during cervical spinal surgery includes a 2017 systematic review and a meta-analysis. Of the 10 studies included in the systematic review, two compared the risk of nerve injury using IONM with no IONM and found no difference.

IONM of the RLN during Esophageal Surgery

Clinical Context and Therapy Purpose

The purpose of intraoperative neurophysiologic monitoring is to provide a treatment option that is an alternative to or an improvement on existing therapies, such as surgery without

neurophysiologic monitoring, in patients who are undergoing esophageal surgery.

The question addressed in this evidence review is: During surgeries that could damage the recurrent laryngeal nerve or peripheral nerves, does neurophysiologic monitoring improve the net health outcome?

The following PICOTS were used to select literature to inform this review.

Patients

The patient population of interest are individuals who are undergoing esophageal surgery.

Interventions

The therapy being considered is intraoperative neurophysiologic monitoring.

Intraoperative neurophysiologic monitoring (IONM) describes a variety of procedures used to monitor the integrity of neural pathways during high-risk neurosurgical, orthopedic, and

vascular surgeries. It involves the detection of electrical signals produced by the nervous system in response to sensory or electrical stimuli to provide information about the functional

integrity of neuronal structures.

Comparators

Comparators of interest include surgery without neurophysiologic monitoring. This operation is managed by thoracic surgeons and primary care providers in an outpatient surgical setting.

Outcomes

The outcomes of interest are morbid events, functional outcomes, and quality of life.

Timing

The existing literature evaluating intraoperative neurophysiologic monitoring as a treatment for patients who are undergoing esophageal surgery has varying lengths of follow up. While

studies described below all reported at least one outcome of interest, longer follow-up was necessary to fully observe outcomes.

Setting

Patients who are undergoing esophageal surgery are actively managed by neurosurgeons, thoracic surgeons and primary care providers in an outpatient surgical setting.

Study Selection Criteria

Methodologically credible studies were selected using the following principles:

    1. To assess efficacy outcomes, comparative controlled prospective trials were sought, with a preference for RCTs;

    2. In the absence of such trials, comparative observational studies were sought, with a preference for prospective studies.

    3. To assess longer term outcomes and adverse events, single-arm studies that capture longer periods of follow-up and/or larger populations were sought.

Studies with overlapping populations were excluded.

One comparative study from Asia by Zhong et al (2014) was identified on RLN monitoring during surgery for esophageal cancer. One hundred fifteen patients with esophageal cancer were enrolled in this prospective study. In 54 patients, the left RLN was found and underwent monitoring. In the remainder (n=61), the RLN was not located. No RLN injury was reported during surgery in either group, but 6 of 61 patients who did not receive monitoring had notable RLN injury identified postoperatively. It is unclear whether the difference in outcomes was due to monitoring or to the inability to identify the RLN during surgery.

Section Summary: IONM of the RLN during Esophageal Surgery

One nonrandomized comparative study on surgery for esophageal cancer was identified. Interpretation of this study is confounded because only the patients who had visual identification of the nerve underwent IONM. Current evidence does not support conclusions on whether IONM reduces RLN injury in patients undergoing surgery for esophageal cancer.

IONM of Peripheral Nerves

Clinical Context and Therapy Purpose

The purpose of intraoperative neurophysiologic monitoring is to provide a treatment option that is an alternative to or an improvement on existing therapies, such as surgery without

neurophysiologic monitoring, in patients who are undergoing surgery proximal to a peripheral nerve.

The question addressed in this evidence review is: In patients undergoing surgeries that could damage their recurrent laryngeal nerve or peripheral nerves, does the use of neurophysiologic monitoring improve the net health outcome?

The following PICOTS were used to select literature to inform this review.

Patients

The patient population of interest are individuals who are undergoing surgery proximal to a peripheral nerve.

Interventions

The therapy being considered is intraoperative neurophysiologic monitoring.

Intraoperative neurophysiologic monitoring (IONM) describes a variety of procedures used to monitor the integrity of neural pathways during high-risk neurosurgical, orthopedic, and

vascular surgeries. It involves the detection of electrical signals produced by the nervous system in response to sensory or electrical stimuli to provide information about the functional

integrity of neuronal structures.

Comparators

Comparators of interest include surgery without neurophysiologic monitoring. This operation is managed by neurosurgeons and primary care providers in an inpatient surgical setting.

Outcomes

The outcomes of interest are morbid events, functional outcomes, and quality of life.

Timing

The existing literature evaluating intraoperative neurophysiologic monitoring as a treatment for patients who are undergoing surgery proximal to a peripheral nerve has varying lengths

of follow up. While studies described below all reported at least one outcome of interest, longer follow-up was necessary to fully observe outcomes.

Setting

Patients who are undergoing surgery proximal to a peripheral nerve are actively managed by neurosurgeons and primary care providers in an inpatient surgical setting.

Study Selection Criteria

Methodologically credible studies were selected using the following principles:

a. To assess efficacy outcomes, comparative controlled prospective trials were sought, with a preference for RCTs;

b. In the absence of such trials, comparative observational studies were sought, with a preference for prospective studies.

c. To assess longer term outcomes and adverse events, single-arm studies that capture longer periods of follow-up and/or larger populations were sought.

Studies with duplicative or overlapping populations were excluded.

Monitoring peripheral nerves during surgery was assessed by Kneist et al (2013) in a case-control study of 30 patients. In patients undergoing total mesorectal excision, impaired anorectal function was observed in 1 (7%) of 15 patients who had IONM compared with 6 (40%) of 15 without. Kneist et al (2013) also reported on erectile function following low anterior rectal resection in a pilot study with 17 patients. In this study, the combined intraoperative measurement of bladder and internal anal sphincter innervation was a strong predictor of postoperative erectile function, with a sensitivity of 90%, specificity of 86%, positive predictive value of 90%, and negative predictive value of 86%. The possibility of intervention during surgery was not addressed.

A 2011 report by Clarkson et al described the use of intraoperative nerve recording for suspected brachial plexus root avulsion. Included in this retrospective review were 25 consecutive patients who underwent intraoperative nerve recording during surgery for unilateral brachial plexus injury. Of 55 roots thought to be avulsed preoperatively, 14 (25%) were found to be intact using intraoperative nerve recording. Eleven of these were then used for reconstruction, of which 9 (82%) had a positive functional outcome. Electrophysiologic monitoring has also been reported to guide selective rhizotomy for glossopharyngeal neuralgia in a series of 8 patients. Use of IONM of peripheral nerves has been reported in patients undergoing orthopedic procedures, including tibial/fibular osteotomies, hip arthroscopy for femoroacetabular impingement, and shoulder arthroplasty.

Section Summary: IONM of Peripheral Nerves

Surgical guidance with peripheral IONM has been reported in case series and 1 case-control study. Other case series have reported on the predictive ability of monitoring of peripheral nerves. No prospective comparative studies identified have assessed whether outcomes are improved with neurophysiologic monitoring.

Summary of Evidence

For individuals who are undergoing thyroid or parathyroid surgery and are at high risk of injury to the recurrent laryngeal nerve (RLN) who receive intraoperative neurophysiologic monitoring (IONM), the evidence includes a large randomized controlled trial (RCT) and systematic reviews. Relevant outcomes are morbid events, functional outcomes, and quality of life. The strongest evidence on neurophysiologic monitoring derives from an RCT of 1000 patients undergoing thyroid surgery. This RCT found a significant reduction in RLN injury in patients at high risk for injury. High risk in this trial was defined as surgery for cancer, thyrotoxicosis, retrosternal or giant goiter, or thyroiditis. The high-risk category may also include patients with prior thyroid or parathyroid surgery or total thyroidectomy. A low volume of surgeries might also contribute to a higher risk for RLN injury. The evidence is sufficient to determine that the technology results in a meaningful improvement in the net health outcome.

For individuals who are undergoing anterior cervical spine surgery and are at high risk of injury to the RLN who receive IONM, the evidence includes systematic reviews of case series and cohort studies. Relevant outcomes are morbid events, functional outcomes, and quality of life. The evidence on the use of IONM to reduce RLN injury during cervical spinal surgery includes a 2017 systematic review and a meta-analysis. Of the 10 studies assessed in the systematic review, two compared the risk of nerve injury with use of IONM vs no IONM and found no difference. The evidence is insufficient to determine the effects of the technology on health outcomes.

For individuals who are undergoing esophageal surgery who receive IONM, the evidence includes a nonrandomized comparative study. Relevant outcomes are morbid events, functional outcomes, and quality of life. One nonrandomized comparative study on surgery for esophageal cancer was identified. Interpretation of this study is confounded because only those patients who had visual identification of the nerve underwent neurophysiologic monitoring. There is insufficient evidence to evaluate whether neurophysiologic monitoring reduces RLN injury in patients undergoing surgery for esophageal cancer. The evidence is insufficient to determine the effects of the technology on health outcomes.

For individuals who are undergoing surgery proximal to a peripheral nerve who receive IONM, the evidence includes case series and a controlled cohort study. Relevant outcomes are morbid events, functional outcomes, and quality of life. Surgical guidance with peripheral IONM and the predictive ability of monitoring of peripheral nerves have been reported. No prospective comparative studies were identified that assessed whether outcomes are improved with neurophysiologic monitoring. The evidence is insufficient to determine the effects of the technology on health outcomes.

Practice Guidelines and Position Statements

American Association of Neurological Surgeons (AANS)/Congress of Neurological Surgeons (CNS)

A 2012 position statement on electrophysiologic monitoring during routine spinal surgery by the American Association of Neurological Surgeons (AANS)/Congress of Neurological Surgeons (CNS) states that intraoperative electrophysiological monitoring during spinal surgery may assist in diagnosing neurologic injury. However, the AANS/CNS finds no evidence that such monitoring either 1) reduces the incidence of neurologic injury or 2) mitigates the severity of it. The position of the AANS/CNS is that routine use of intraoperative electrophysiologic monitoring is neither warranted nor recommended, although intraoperative electrophysiologic monitoring should be performed if the diagnostic information gained is of value, particularly in high-risk cases such as deformity, gross instability, navigation through or around peripheral nerves, or intramedullary procedures.

A 2014 guideline update from AANS/CNS found no conflicting evidence with their previous recommendations for intraoperative monitoring for lumbar fusion. They found no evidence that intraoperative monitoring can prevent injury to the nerve roots. They found limited evidence that intraoperative monitoring can indicate a medial pedicle breach by a pedicle screw, but once a nerve root injury has taken place, changing the direction of the screw does not alter the outcome.

American Association of Neuromuscular & Electrodiagnostic Medicine

A 2014 position statement on SSEPs from the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) states that intraoperative SEPs have demonstrated usefulness for monitoring of spinal cord, brainstem, and brain sensory tracts. AANEM states that intraoperative SEP monitoring is indicated for selected spine surgeries in which there is a risk of additional nerve root or spinal cord injury. Indications for SEP monitoring may include, but are not limited to, complex, extensive, or lengthy procedures, and when mandated by hospital policy.

American Clinical Neurophysiology Society

In 2009 the American Clinical Neurophysiology Society (ACNS) published recommended standards for intraoperative neurophysiologic monitoring. Guideline 11A includes the following statement:


“The monitoring team should be under the direct supervision of a physician with training and experience in NIOM. The monitoring physician should be licensed in the state and privileged to interpret neurophysiologic testing in the hospital in which the surgery is being performed. He/she is responsible for real-time interpretation of NIOM data. The monitoring physician should be present in the operating room or have access to NIOM data in real-time from a remote location and be in communication with the staff in the operating room. There are many methods of remote monitoring however any method used must conform to local and national protected health information guidelines. The monitoring physician must be available to be in the operating room, and the specifics of this availability (i.e., types of surgeries) should be decided by the hospital credentialing committee. In order to devote the needed attention, it is recommended that the monitoring physician interpret no more than three cases concurrently.”

American Academy of Neurology

AAN published an assessment of IONM in 1990 with an evidence-based guideline update in 2012 by the AAN and ACNS. The 1990 assessment indicates that monitoring requires a team approach with a well-trained physician-neurophysiologist to provide or supervise monitoring. EEG monitoring is used during carotid endarterectomy or for other similar situations in which cerebral blood flow is at high risk. Electrocorticography from surgically exposed cortex can help to define the optimal limits of a surgical resection or identify regions of greatest impairment, while sensory cortex SSEPs can help to localize the central fissure and motor cortex. Auditory-evoked potentials, along with cranial nerve monitoring can be used during posterior fossa neurosurgical procedures. Spinal cord SSEPs are frequently used to monitor the spinal cord during orthopedic or neurosurgical procedures around the spinal cord, or cross-clamping of the thoracic aorta. EMG monitoring during procedures around the roots and peripheral nerves can be used to warn of excessive traction or other impairment of motor nerves. At the time of the 1990 assessment, MEPs were considered investigational by many neurophysiologists. The 2012 update, which was endorsed by the AANEM, concluded that the available evidence supports IONM using SSEPs or MEPs when conducted under the supervision of a clinical neurophysiologist experienced with IONM. Evidence was insufficient to evaluate IOMN when conducted by technicians alone or by an automated device.

AAN published a model policy on principles of coding for intraoperative neurophysiologic monitoring (IOM) and testing in 2012. The background section of this document provides the following information on the value of IOM in averting neural injuries during surgery:

  1. Value of EEG Monitoring in Carotid Surgery. Carotid occlusion, incident to carotid endarterectomies, poses a high risk for cerebral hemispheric injury. EEG monitoring is capable of detecting cerebral ischemia, a serious prelude to injury. Studies of continuous monitoring established the ability of EEG to correctly predict risks of postoperative deficits after a deliberate, but necessary, carotid occlusion as part of the surgical procedure. The surgeon can respond to adverse EEG events by raising blood pressure, implanting a shunt, adjusting a poorly functioning shunt, or performing other interventions.

  1. Multicenter Data in Spinal Surgeries. An extensive multicenter study conducted in 1995 demonstrated that IOM using SEP reduced the risk of paraplegia by 60% in spinal surgeries. The incidence of false negative cases, wherein an operative complication occurred without having been detected by the monitoring procedure, was small: 0.06%.

  1. Technology Assessment of Monitoring in Spinal Surgeries. A technology assessment by the McGill University Health Center reviewed 11 studies and concluded that spinal IOM is capable of substantially reducing injury in surgeries that pose a risk to spinal cord integrity. It recommended combined SEP/MEP monitoring, under the presence or constant availability of a monitoring physician, for all cases of spinal surgery for which there is a risk of spinal cord injury.

  1. Value of Combined Motor and Sensory Monitoring. Numerous studies of post-surgical paraparesis and quadriparesis have shown that both SEP and MEP monitoring had predicted adverse outcomes in a timely fashion. The timing of the predictions allowed the surgeons the opportunity to intervene and prevent adverse outcomes. The two different techniques (SEP and MEP) monitor different spinal cord tracts. Sometimes, one of the techniques cannot be used for practical purposes, for anesthetic reasons, or because of preoperative absence of signals in those pathways. Thus, the decision about which of these techniques to use needs to be tailored to the individual patient’s circumstances.

  1. Protecting the Spinal Cord from Ischemia during Aortic Procedures. Studies have shown that IOM accurately predicts risks for spinal cord ischemia associated with clamping the aorta or ligating segmental spinal arteries. IOM can assess whether the spinal cord is tolerating the degree of relative ischemia in these procedures. The surgeon can then respond by raising blood pressure, implanting a shunt, re-implanting segmental vessels, draining spinal fluid, or through other interventions.

  1. Value of EMG Monitoring. Selective posterior rhizotomy in cerebral palsy significantly reduces spasticity, increases range of motion, and improves functional skills. Electromyography during this procedure can assist in selecting specific dorsal roots to transect. EMG can also be used in peripheral nerve procedures that pose a risk of injuries to nerves.

  1. Value of Spinal Monitoring using SSEP and MEPs. According to a recent review of spinal monitoring using SSEP and MEPs by the Therapeutics and Technology Assessment Subcommittee of AAN and ACNS, IOM is established as effective to predict an increased risk of the adverse outcomes of paraparesis, paraplegia, and quadriplegia in spinal surgery (4 Class I and 7 Class II studies). Surgeons and other members of the operating team should be alerted to the increased risk of severe adverse neurologic outcomes in patients with important IOM changes (Level A).

The AAN model policy also offered guidance on personnel and monitoring standards for IONM and SSEP.

American Society of Neurophysiological Monitoring

In 2018, the American Society of Neurophysiological Monitoring (ASNM) published practice guidelines on the supervising professional on IONM. The ASNM 2013 position statement on intraoperative MEP monitoring indicated that MEPs are an established practice option for cortical and subcortical mapping and for monitoring during surgeries risking motor injury in the brain, brainstem, spinal cord or facial nerve.

National Institute for Health and Care Excellence

A 2008 guidance from the U.K.’s National Institute for Health and Care Excellence on intraoperative nerve monitoring during thyroid surgery found no major safety concerns. In terms of efficacy, IONM was indicated as helpful “in performing more complex operations such as reoperative surgery and operations on large thyroid glands.

U.S. Preventive Services Task Force Recommendations

Not applicable.

Key Words:

Intra-operative neurophysiologic monitoring, IONM, sensory-evoked potentials, somatosensory-evoked potentials (SSEPs), Brainstem auditory-evoked potentials (BAEPs), Visual-evoked potentials (VEPs), Electromyogram (EMG), Motor-evoked potential, electroencephalogram (EEG), electrocorticography (ECoG), nerve conduction velocity, transcranial magnetic stimulation, Digitimer electrical cortical stimulator

Approved by Governing Bodies:

A number of electroencephalography and electromyography monitors have been cleared for marketing by the U.S. Food and Drug Administration (FDA) through the 510(k) process.

Intraoperative neurophysiologic monitoring of motor-evoked potentials using transcranial magnetic stimulation does not have FDA approval.

Benefit Application:

Coverage is subject to member’s specific benefits.  Group specific policy will supersede this policy when applicable.

ITS: Home Policy provisions apply

FEP contracts: Special benefit consideration may apply.  Refer to member’s benefit plan.  FEP does not consider investigational if FDA approved and will be reviewed for medical necessity.

Current Coding:

CPT codes: 

92585

Auditory evoked potentials for evoked response audiometry and/or testing of the central nervous system; comprehensive

95829 

Electrocorticogram at surgery (separate procedure)

95865 

Needle electromyography; larynx

95867

Needle electromyography; cranial nerve supplied muscle(s), unilateral

95868 

Needle electromyography; cranial nerve supplied muscles, bilateral

95885 

Needle electromyography, each extremity, with related paraspinal areas, when performed, done with nerve conduction, amplitude and latency/velocity study; limited (list separately in addition to code for primary procedure)

95886

; complete, five or more muscles studied, innervated by three or more nerves or four or more spinal levels (list separately in addition to code for primary procedure)

95887 

Needle electromyography, non-extremity (cranial nerve supplied or axial) muscle(s) done with nerve conduction, amplitude and latency/velocity study (list separately in addition to code for primary procedure)

95907 

Nerve conduction studies; 1-2 studies

95908 

Nerve conduction studies; 3-4 studies

95909

Nerve conduction studies; 5-6 studies

95910

Nerve conduction studies; 7-8 studies

95911  

Nerve conduction studies; 9-10 studies

95912  

Nerve conduction studies; 11-12 studies

95913 

Nerve conduction studies; 13 or more studies

95925

Short-latency somatosensory evoked potential study, stimulation of any/all peripheral nerves or skin sites, recording from the central nervous system; in upper limbs

95926  

Short-latency somatosensory evoked potential study, stimulation of any/all peripheral nerves or skin sites, recording from the central nervous system; in lower limbs

95927 

Short-latency somatosensory evoked potential study, stimulation of any/all peripheral nerves or skin sites, recording from the central nervous system; in the trunk or head

95928

Central motor evoked potential study (transcranial motor stimulation); upper limbs

95929   

; lower limbs

95930

Visual evoked potential (VEP) checkerboard or flash testing, central nervous system glaucoma, with interpretation and report.

95940

Continuous intraoperative neurophysiology monitoring in the operating room, one on one monitoring requiring personal attendance, each 15 minutes (List separately in addition to code for primary procedure)

95941 

Continuous intraoperative neurophysiology monitoring, from outside the operating room (remote or nearby) or for monitoring of more than one case while in the operating room, per hour (List separately in addition to code for primary procedure)

95955

Electroencephalogram (EEG) during non-intracranial surgery (e.g., carotid surgery)

 

HCPCS Codes:

G0453

Continuous intraoperative neurophysiology monitoring, from outside the operating room (remote or nearby), per patient, (attention directed exclusively to one patient) each 15 minutes (list in addition to primary procedure)

                

CPT Codes 95940 and 95941 and HCPCS Code G0453 would be reported in conjunction with the code(s) for the testing performed, i.e., 92585, 95822, 95860-95870, 95907-95913, and 95925-95939.

References:

  1. Ajiboye RM, Zoller SD, Sharma A, et al. intraoperative neuromonitoring for anterior cervical spine surgery: What is the evidence? Spine (Phila Pa 1976). Mar 15 2017; 42(6):385-393.

  2. American Academy of Neurology. Therapeutics and Technology Assessment Subcommittee.  Assessment: Intraoperative neurophysiology. Neurology 1990; 40(11): 1644-1646.

  3. American Academy of Neurology. Principles of coding for intraoperative neurophysiologic monitoring (IOM) and testing. American Academy of Neurology Professional Association.  Model Medical Policy. April 23, 2008.

  4. American Academy of Neurology. Principles of Coding for Intraoperative Neurophysiologic Monitoring (IOM) and Testing Model Policy. 2012; www.aan.com/uploadedFiles/Website_Library_Assets/Documents/3.Practice_Management/1.Reimbursement/1.Billing_and_Coding/5.Coverage_Policies/Coverage%20Policies%20-%20IONM.pdf. Accessed March 23, 2018.

  5. American Association of Neurological Surgeons (AANS)/Congress of Neurological Surgeons (CNS). Guidelines for the performance of fusion procedures for degenerative disease of the lumbar spine. Part 15: electrophysiological monitoring and lumbar fusion. J Neurosurg Spine. 2005 Jun; 2(6):725-732. http://www.spinesection.org/fusion_guidelines.php. Accessed March, 201

  6. American Clinical Neurophysiology Society.  Guideline 11A.  Recommended Standards for Neurophysiologic Intraoperative Monitoring—Principles.  Available online at www.acns.org/pdfs/Guideline%2011A.pdf. Accessed March 23, 2018.

  7. American Clinical Neurophysiology Society. ACNS guidelines. 2009; www.acns.org/practice/guidelines. Accessed  March 23, 2018.

  8. American Association of Neuromuscular & Electrodiagnostic Medicine. Recommended Policy for Electrodiagnostic Medicine. 2013; www.aanem.org/getmedia/4eb449e2-c705-45b7-a5df-7cf024bb4b74/2014-Recommended_Policy_EDX_Medicine_.pdf.aspx. Accessed March 23, 2018.

  9. Aminoff MJ.  Intraoperative monitoring by evoked potentials for spinal cord surgery:  The cons.  Electroencephalographic Clinics of Neurophysiology 1989; 73(5): 378-380.

  10. Barczynski M, Konturek A, Cichon S. Randomized clinical trial of visualization versus neuromonitoring of recurrent laryngeal nerves during thyroidectomy. Br J Surg. Mar 2009; 96(3):240-246.

  11. Chan M, Gin T, and Goh K.  Interventional neurophysiologic monitoring.  Current Opinion in Anesthesiology 2004; 17: 389-396.

  12. Chen Y, He Z, Yang H, et al. Anterior cervical diskectomy and fusion for adjacent segment disease. Orthopedics. Apr 2013; 36(4):e501-508.

  13. Clarkson JH, Ozyurekoglu T, Mujadzic M et al. An evaluation of the information gained from the use of intraoperative nerve recording in the management of suspected brachial plexus root avulsion. Plast Reconstr Surg 2011; 127(3):1237-43.

  14. Daubod JR.  Intraoperative monitoring by evoked potentials for spinal cord surgery:  The pros.  Electroencephalographic Clinics of Neurophysiology 1989; 73(5): 374-377.

  15. Dinkel M, Beese U, and Messner M.  Intraoperative neurophysiologic monitoring.  The Internet Journal of Neuromonitoring 2001, Vol. 2, No. 2.

  16. Dimopoulos VG, Chung I, Lee GP, et al. Quantitative estimation of the recurrent laryngeal nerve irritation by employing spontaneous intraoperative electromyographic monitoring during anterior cervical discectomy and fusion. J Spinal Disord Tech. Feb 2009; 22(1):1-7.

  17. Erwood MS, Hadley MN, Gordon AS, et al. Recurrent laryngeal nerve injury following reoperative anterior cervical discectomy and fusion: a meta-analysis. J Neurosurg Spine. Aug 2016; 25(2):198-204.

  18. Fisher RS, Reddens P, and Nunemacher M.  Efficacy of intraoperative neurophysiological monitoring.  Journal of Clinical Neurophysiology 1995; 12(1): 97-109.

  19. Jahangiri FR. Multimodality neurophysiological monitoring during tibial/fibular osteotomies for preventing peripheral nerve injuries. Neurodiagn J 2013; 53(2):153-68.

  20. Jameson LC and Sloan TB.  Monitoring of the brain and spinal cord.  Anesthesiology Clinics of North America 2006, Vol. 24, No. 4.

  21. Henry BM, Graves MJ, Vikse J, et al. The current state of intermittent intraoperative neural monitoring for prevention of recurrent laryngeal nerve injury during thyroidectomy: a PRISMA-compliant systematic review of overlapping meta-analyses. Langenbecks Arch Surg. Jun 2017; 402(4):663-673.

  22. Kneist W, Kauff DW, Juhre V, et al. Is intraoperative neuromonitoring associated with better functional outcome in patients undergoing open TME? Results of a case-control study. Eur J Surg Oncol. Sep 2013; 39(9):994-999.

  23. Kneist W, Kauff DW, Rubenwolf P, et al. Intraoperative monitoring of bladder and internal anal sphincter innervation: a predictor of erectile function following low anterior rectal resection for rectal cancer? Results of a prospective clinical study. Dig Surg. 2013; 30(4-6):459-465.

  24. Langeloo Dd, Lelivelt A, Louis Journee H, et al.  Transcranial electrical motor-evoked potential monitoring during surgery for spinal deformity: a study of 145 patients.  Spine 2003; 28(10); 1043-50.

  25. Lee MJ, Bazaz R, Furey CG, et al. Risk factors for dysphagia after anterior cervical spine surgery: a two-year prospective cohort study. Spine J. Mar-Apr 2007; 7(2):141-147.

  26. Macdonald DB, Skinner S, Shils J et al. Intraoperative motor evoked potential monitoring - A position statement by the American Society of Neurophysiological Monitoring. Clin Neurophysiol 2013; 124(12):2291-316Malhotra NR and Shaffrey CI.  Intraoperative electrophysiological monitoring in spine surgery. Spine 2010; 35(25):2167-79.

  27. Nagda SH, Rogers KJ, Sestokas AK et al. Neer Award 2005: Peripheral nerve function during shoulder arthroplasty using intraoperative nerve monitoring. J Shoulder Elbow Surg 2007; 16(3 Suppl):S2-8.

  28. National Institute for Health and Care Excellence. Intraoperative nerve monitoring during thyroid surgery. 2008. Available online at: www.nice.org.uk/nicemedia/live/11872/40081/40081.pdf. Last Accessed March 23, 2018.

  29. Nuwer MR.  Regulatory and medical-legal aspects of intraoperative monitoring.  Journal of Clinical Neurophysiology 2002; 19(5): 387-395.

  30. Nuwer MR, Emerson RG, Galloway G et al. Evidence-based guideline update:  intraoperative spinal monitoring with somatosensory and transcranial electrical motor evoked potentials: report of the Therapeutics and Technology Assessment Subcommittee of the Americal Academy of Neurology and the American Clinical Neurophysiology Society.  Neurology 2012; 78(8):585-9.

  31. Ochs BC, Herzka A, Yaylali I. Intraoperative neurophysiological monitoring of somatosensory evoked potentials during hip arthroscopy surgery. Neurodiagn J 2012; 52(4):312-9.

  32. Ota T, Kawai K, Kamada K et al. Intraoperative monitoring of cortically recorded visual response for posterior visual pathway. J Neurosurg 2010; 112(2):285-94.

  33. Papworth D.  Intraoperative monitoring during vascular surgery. Anesthesiology Clinics of North America 2004, Vol. 22, No. 2.

  34. Pardal-Refoyo JL, Ochoa-Sangrador C. Bilateral recurrent laryngeal nerve injury in total thyroidectomy with or without intraoperative neuromonitoring. Systematic review and meta-analysis. Acta Otorrinolaringol Esp. Mar-Apr 2016; 67(2):66-74.

  35. Romstock J, Strauss C, Fahlbusch R. Continuous electromyography monitoring of motor cranial nerves during cerebellopontine angle surgery. J Neurosurg 2000; 93(4):586-93Sala F, Palandra G, Basso E, et al.  Motor evoked potential monitoring improves outcome after surgery for intramedullary spinal cord tumors: a historical control study.  Neurosurgery 2006; 58(6):1129-43.

  36. Sasaki T, Itakura T, Suzuki K et al.  Intraoperative monitoring of visual evoked potential:  introduction of a clinically useful method.  J Neurosurg 2010; 112(2):273-84.

  37. Schwartz DM, Auerbach JD, Dormans JP et al. Neurophysiological detection of impending spinal cord injury during scoliosis surgery. J Bone Joint Surg Am 2007; 89(11):2440-9.

  38. Schweiger H, Kamp HD and Dinkel M. Somatosensory-evoked potentials during carotid artery surgery: Experience in 400 operations.  Surgery 1991; 109(5): 602-609.

  39. Sharan A, Groff MW, Dailey AT, et al. Guideline update for the performance of fusion procedures for degenerative disease of the lumbar spine. Part 15: electrophysiological monitoring and lumbar fusion. J Neurosurg Spine 2014; 2014/07/02:102-105. Available at: //thejns.org/doi/pdf/10.3171/2014.4.SPINE14324.

  40. Shine TSJ, Harrison BA, De Ruyter MS, et al.  Motor and somatosensory evoked potentials: their role in predicting spinal cord ischemia in patients undergoing thoracoabdominal aortic aneurysm repair with regional lumbar epidural cooling. Anesthesiology 2008; 108(4):580-7.

  41. Skinner SA, Cohen BA, Morledge DE, et al. Practice guidelines for the supervising professional: intraoperative neurophysiological monitoring. J Clin Monit Comput. Apr 2014; 28(2):103-111.

  42. Sun W, Liu J, Zhang H, et al. A meta-analysis of intraoperative neuromonitoring of recurrent laryngeal nerve palsy during thyroid reoperations. Clin Endocrinol (Oxf). Nov 2017; 87(5):572-580.

  43. Tan TP, Govindarajulu AP, Massicotte EM, et al. Vocal cord palsy after anterior cervical spine surgery: a qualitative systematic review. Spine J. Jul 1 2014; 14(7):1332-1342.

  44. Vasileiadis I, Karatzas T, Charitoudis G, et al. Association of intraoperative neuromonitoring with reduced recurrent laryngeal nerve injury in patients undergoing total thyroidectomy. JAMA Otolaryngol Head Neck Surg. Oct 1 2016; 142(10):994-1001.

  45. Zhang W, Chen M, Zhang W, et al. Use of electrophysiological monitoring in selective rhizotomy treating glossopharyngeal neuralgia. J Craniomaxillofac Surg. Jul 2014; 42(5):e182-185.

  46. Zhong D, Zhou Y, Li Y, et al. Intraoperative recurrent laryngeal nerve monitoring: a useful method for patients with esophageal cancer. Dis Esophagus. Jul 2014; 27(5):444-451.

Policy History:

Medical Policy Group, March 2007 (3)

Medical Policy Administration Committee, April 2007

Available for comment April 12-May 26, 2007

Medical Policy Group, March 2009 (1)

Medical Policy Group, June 2009 (2)

Medical Policy Administration Committee, July 2009

Available for comment July 1-August 14, 2009

Medical Policy Panel, July 2011

Medical Policy Group, August 2011 (2): Update Description, Key Points, Key Words, Government Approval, References

Medical Policy Administration Committee, August 2011

Available for comment August 11 – September 26, 2011

Medical Policy Group, December 2011 (3): Added new 2012 Codes – 95885, 95886, 95887

Medical Policy Panel, March 2012

Medical Policy Group, September 2012 (2); Policy statements changed to indicate motor-evoked potentials using transcranial electrical stimulation meets coverage criteria and motor-evoked potential using transcranial magnetic stimulation is investigational.  Key Points and References updated to support Policy changes.

Medical Policy Administration Committee, September 2012

Available for comment September 18 through October 31, 2012

Medical Policy Group, November 2012: Added new 2013 Codes G0453, 95940, 95941, 95907, 95908, 95909, 95910, 95911, 95912, & 95913 effective January 1, 2013; Deleted Codes 95920, 95900, 95903, & 95904 effective January 1, 2013.

Medical Policy Panel, December 2012

Medical Policy Group, August 2013 (2): Updated Key Points and References from literature search through October 2012.   No change in policy statement. 

Medical Policy Panel, May 2014

Medical Policy Group, July 2014 (4): Updated Key Points and References. No changes to the policy at this time.

Medical Policy Panel, May 2015

Medical Policy Group, May 2015 (6):  Updates to Key Points, Approved by Governing Bodies, and References; no change to policy statement.

Medical Policy Group, March 2016 (6):  Clarification to policy statement; no change in policy intent.

Medical Policy Group, July 2016: Removed Policy section prior to November 1, 2012 in policy cleanup.

Medical Policy Panel, May 2017

Medical Policy Group, June 2017 (6): Updates to Description, Policy statement edited to allow coverage for monitoring of the Recurrent Laryngeal Nerve, Key points, Key Words, Practice Guidelines, Governing Bodies, Coding, and References.

Medical Policy Group, December 2017. Annual Coding Update 2018. Updated verbiage for revised cpt code 95930.

Medical Policy Panel April 2018

Medical Policy Group, May 2018 (6): Updates to Key Points and References.

Medical Policy Group, October 2018 (3): Corrected Typo; Removed double underline; Added note in the coding section for processing guidelines for CPT codes 95940, 95941 and HCPCS Code G0453.

Medical Policy Panel, April 2019

Medical Policy Group, May 2019 (3): 2019 Updates to Key Points, Practice Guidelines and Position Statements, References, and Key Words: added IONM. Revised policy statement for clarification of criteria. Removed third criteria point in policy statement related to physician monitoring and interpretation of cases. Placed on DRAFT May 13, 2019 for 45 days for comment.

 

 

This medical policy is not an authorization, certification, explanation of benefits, or a contract. Eligibility and benefits are determined on a case-by-case basis according to the terms of the member’s plan in effect as of the date services are rendered. All medical policies are based on (i) research of current medical literature and (ii) review of common medical practices in the treatment and diagnosis of disease as of the date hereof. Physicians and other providers are solely responsible for all aspects of medical care and treatment, including the type, quality, and levels of care and treatment.

 

This policy is intended to be used for adjudication of claims (including pre-admission certification, pre-determinations, and pre-procedure review) in Blue Cross and Blue Shield’s administration of plan contracts.

The plan does not approve or deny procedures, services, testing, or equipment for our members. Our decisions concern coverage only. The decision of whether or not to have a certain test, treatment or procedure is one made between the physician and his/her patient. The plan administers benefits based on the member’s contract and corporate medical policies. Physicians should always exercise their best medical judgment in providing the care they feel is most appropriate for their patients. Needed care should not be delayed or refused because of a coverage determination.

As a general rule, benefits are payable under health plans only in cases of medical necessity and only if services or supplies are not investigational, provided the customer group contracts have such coverage.

The following Association Technology Evaluation Criteria must be met for a service/supply to be considered for coverage:

1. The technology must have final approval from the appropriate government regulatory bodies;

2. The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes;

3. The technology must improve the net health outcome;

4. The technology must be as beneficial as any established alternatives;

5. The improvement must be attainable outside the investigational setting.

 

Medical Necessity means that health care services (e.g., procedures, treatments, supplies, devices, equipment, facilities or drugs) that a physician, exercising prudent clinical judgment, would provide to a patient for the purpose of preventing, evaluating, diagnosing or treating an illness, injury or disease or its symptoms, and that are:

1. In accordance with generally accepted standards of medical practice; and

2. Clinically appropriate in terms of type, frequency, extent, site and duration and considered effective for the patient’s illness, injury or disease; and

3. Not primarily for the convenience of the patient, physician or other health care provider; and

4. Not more costly than an alternative service or sequence of services at least as likely to produce equivalent therapeutic or diagnostic results as to the diagnosis or treatment of that patient’s illness, injury or disease.