CAM 70173

Gastric Electrical Stimulation

Category:Surgery   Last Reviewed:October 2018
Department(s):Medical Affairs   Next Review:October 2019
Original Date:December 2000    

Description:
Gastric electrical stimulation (GES) is performed using an implantable device designed to treat chronic drug-refractory nausea and vomiting secondary to gastroparesis of diabetic, idiopathic, or postsurgical etiology. GES has also been investigated as a treatment of obesity. The device may be referred to as a gastric pacemaker.

For individuals who have gastroparesis who receive GES, the evidence includes randomized controlled trials (RCTs) and systematic reviews. Relevant outcomes are symptoms and treatment-related morbidity. Five crossover RCTs have been published. A 2017 meta-analysis of these 5 RCTs did not find a significant benefit of GES on the severity of symptoms associated with gastroparesis. Patients generally reported improved symptoms at follow-up whether or not the device was turned on, suggesting a placebo effect. 

For individuals who have obesity who receive GES, the evidence includes 1 published RCT. Relevant outcomes are change in disease status and treatment-related morbidity. The SHAPE trial did not show significant improvement in weight loss with GES compared to sham stimulation. The evidence is insufficient to determine the effects of the technology on health outcomes.  

Background
GASTROPARESIS
Gastroparesis is a chronic disorder of gastric motility characterized by delayed emptying of a solid meal. Symptoms include bloating, distension, nausea, and vomiting. When severe and chronic, gastroparesis can be associated with dehydration, poor nutritional status, and poor glycemic control in diabetic patients. While most commonly associated with diabetes, gastroparesis is also found in chronic pseudo- obstruction, connective tissue disorders, Parkinson's disease, and psychological pathologic conditions.
Some cases may not be associated with an identifiable cause and are referred to as idiopathic gastroparesis. Treatment of gastroparesis includes prokinetic agents (e.g., metoclopramide) and antiemetic agents (e.g., metoclopramide, granisetron, ondansetron). Severe cases may require enteral or total parenteral nutrition.

Treatment
Gastric electrical stimulation (GES), also referred to as gastric pacing, using an implantable device, has been investigated primarily as a treatment for gastroparesis. Currently available devices consist of a pulse generator, which can be programmed to provide electrical stimulation at different frequencies, connected to intramuscular stomach leads, which are implanted during laparoscopy or open laparotomy (see Regulatory Status section).

OBESITY
GES has also been investigated as a treatment of obesity. It is used to increase a feeling of satiety with subsequent reduction in food intake and weight loss. The exact mechanisms resulting in changes in eating behavior are uncertain but may be related to neurohormonal modulation and/or stomach muscle stimulation.  

Regulatory Status
In 2000, the Gastric Electrical Stimulator (GES) system (now called Enterra™ Therapy System; Medtronic, Minneapolis, MN) was approved by the U.S. Food and Drug Administration (FDA) through the humanitarian device exemption process (HDE Approval H990014) for the treatment of gastroparesis. The GES system consists of 4 components: the implanted pulse generator, 2 unipolar intramuscular stomach leads, the stimulator programmer, and the memory cartridge. With the exception of the intramuscular leads, all other components have been used in other implantable neurologic stimulators, such as spinal cord or sacral nerve stimulation. The intramuscular stomach leads are implanted either laparoscopically or during a laparotomy and are connected to the pulse generator, which is implanted in a subcutaneous pocket. The programmer sets the stimulation parameters, which are typically set at an "on" time of 0.1 second alternating with an "off" time of 5.0 seconds.

Currently, no GES devices have been approved by FDA for the treatment of obesity. The Transcend® (Transneuronix; acquired by Medtronic in 2005), an implantable gastric stimulation device, is available in Europe for treatment of obesity.

Related Policies
70120 Vagus Nerve Stimulation

Policy:
Gastric electrical stimulation (GES) may be considered MEDICALLY NECESSARY for gastroparesis when all of the following are present: 

  1. The patient has a history of recurrent episodes of severe nausea/vomiting for more than 12 months and undergone comprehensive medical therapy for a minimum of six months
  2. Upper endoscopy demonstrates no evidence of gastric outlet obstruction
  3. Imaging, either barium upper GI or abdominal CT, demonstrates no evidence of foregut obstruction
  4. There is abnormal gastric emptying confirmed by nuclear study
    • One hour testing with > 50% retention of liquids, and/or
    • Two hour testing with > 60% retention of solids, and/or
    • Four hour testing with > 10% retention of solids.
  5. The patient is refractory to maximum pharmacologic intervention including
    • Prokinetics – metoclopramide and erythromycin
    • Antiemetics – antihistamine receptors, 5-HT antagonists, or dronabinol
  6. The patient has undertaken dietary modifications under the supervision of a registered dietician
  7. The patient’s care is provided by a multi-disciplinary team including surgeon, gastroenterologist and registered dietician
  8. The procedure is performed at a center with IRB approval and oversight

All other uses of gastric electrical stimulation (GES) are considered INVESTIGATIONAL.

Policy Guidelines
There are CPT codes that are specific to insertion of the gastric stimulation device:

43647: Laparoscopy, surgical; implantation or replacement of gastric neurostimulator electrodes, antrum 
43648: revision or removal of gastric neurostimulator electrodes, antrum 
43881: Implantation or replacement of gastric neurostimulator electrodes, antrum, open 
43882: Revision or removal of gastric neurostimulator electrodes, antrum, open 
64590: Insertion or replacement of peripheral or gastric neurostimulator pulse generator or receiver, direct or inductive coupling 
64595: Revision or removal of peripheral or gastric neurostimulator pulse generator or receiver 

There are also specific codes for electronic analysis and programming of gastric neurostimulator pulse generator:

95980: Electronic analysis of implanted neurostimulator pulse generator system (e.g., rate, pulse amplitude and duration, configuration of wave form, battery status, electrode selectability, output modulation, cycling, impedance and patient measurements), gastric neurostimulator pulse generator/transmitter; intraoperative, with programming
95981: subsequent, without reprogramming
95982: subsequent, with reprogramming

Prior to 2012, when the procedure was performed in the treatment of obesity, there were specific category III CPT codes:

0155T: Laparoscopy, surgical; implantation or replacement of gastric stimulation electrodes, lesser curvature (i.e., morbid obesity)
0156T: revision or removal of gastric stimulation electrodes, lesser curvature (i.e., morbid obesity)
0157T: Laparotomy, implantation or replacement of gastric stimulation electrodes, lesser curvature (i.e., morbid obesity)
0158T: Laparotomy, revision or removal of gastric stimulation electrodes, lesser curvature (i.e., morbid obesity)

The CPT code book instructs that after Jan. 1, 2012, laparoscopic procedures related to gastric stimulation electrodes for morbid obesity should be reported using code 43659 (unlisted laparoscopy procedure, stomach), and laparotomy procedures related to gastric stimulation electrodes for morbid obesity should be reported using 43999 (unlisted procedure, stomach).

The insertion of the gastric neurostimulator pulse generator is coded with 64590, and revision or removal of the pulse generator is coded with 64595, regardless of the indication.

The following HCPCS codes may be used:

L8680: Implantable neurostimulator electrode, each (implant requires 2 leads)
L8685: Implantable neurostimulator pulse generator, single array, rechargeable, includes extension
L8686: Implantable neurostimulator pulse generator, single array, non-rechargeable, includes extension
L8687: Implantable neurostimulator pulse generator, dual array, rechargeable, includes extension
L8688: Implantable neurostimulator pulse generator, dual array, non-rechargeable, includes extension 

Benefit Application
BlueCard®/National Account Issues
State or federal mandates (e.g., FEP) may dictate that all devices approved by the U.S. Food and Drug Administration (FDA) may not be considered investigational. Therefore, FDA-approved devices may be assessed only on the basis of their medical necessity.

Rationale
This evidence review was created in December 2000 and has been updated regularly with searches of the MEDLINE database. The most recent literature update was performed through December 11, 2017.

Evidence reviews assess the clinical evidence to determine whether the use of a technology improves the net health outcome. Broadly defined, health outcomes are 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 to managing the course of that condition. Validated outcome measures are necessary 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.

To assess whether the evidence is sufficient to draw conclusions about the net health outcome of a technology, 2 domains are examined: the relevance and the quality and credibility. To be relevant, studies must represent one or more intended clinical uses of the technology in the intended population and compare an effective and appropriate alternative at a comparable intensity. For some conditions, the alternative will be supportive care or surveillance. The quality and credibility of the evidence depend on study design and conduct, minimizing bias and confounding that can generate incorrect findings. The randomized controlled trial (RCT) is preferred 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. The following is a summary of the key literature to date. 

GASTRIC ELECTRICAL STIMULATION FOR GASTROPARESIS 
Systematic Reviews
Several systematic reviews of studies on gastric electrical stimulation (GES) for gastroparesis have been published,1-3  the most recent and comprehensive of which is by Levinthal et al (2017).1 To be selected for the Levinthal review, studies had to include adults with established gastroparesis, report patient symptom scores, and administer treatment for at least 1 week. Five RCTs and 13 non-RCTs meeting criteria were identified. Pooled analysis of data from the 5 RCTs (n=185 patients) did not find a statistically significant difference in symptom severity when the GES was turned on vs off (standardized mean difference [SMD], 0.17; 95% confidence interval [CI], -0.06 to 0.40; p=0.15). Another pooled analysis did not find a statistically significant difference in nausea severity scores when the GES was on or off (SMD, -0.143; 95% CI, -0.50 to 0.22; p=0.45). In a pooled analysis of 13 open-label single-arm studies and data from open-label extensions of 3 RCTs, mean total symptom severity score decreased 2.68 (95% CI, 2.04 to 3.32) at follow-up from a mean of 6.85 (95% CI, 6.28 to 7.42) at baseline. The rate of adverse events in the immediate postoperative period (reported in 7 studies) was 8.7% (95% CI, 4.3% to 17.1%). The in- hospital mortality rate within 30 days of surgery was 1.4% (95% CI, 0.8% to 2.5%), the rate of reoperations (up to 10 years of follow-up) was 11.1% (95% CI, 8.7% to 14.1%), and the rate of device removal was 8.4% (95% CI, 5.7% to 12.2%). 

Randomized Controlled Trials
Representative crossover RCTs are described next. Abell et al (2003) reported findings from the Worldwide Anti-Vomiting Electrical Stimulation Study (WAVESS).4 This double-blind crossover study, initially described in Food and Drug Administration materials, included 33 patients with intractable idiopathic or diabetic gastroparesis.5 The primary end point was a reduction in vomiting frequency, as measured by patient diaries. In the initial phase of the study, all patients underwent implantation of the stimulator and were randomly and blindly assigned to stimulation on or stimulation off for the first month, with crossover to off and on during the second month. Baseline vomiting frequency was 47 episodes per month, which declined in both on and off groups to 23 to 29 episodes, respectively. However, no statistically significant differences were found in the number of vomiting episodes between groups, suggesting a placebo effect. In the second, open-label, phase of the trial, all patients had their stimulators turned on for the remainder of the 6- to 12-month follow-up. During this period, vomiting frequency declined in both the idiopathic and diabetic subgroups.

McCallum et al (2010) reported on a crossover RCT evaluating GES (Enterra device) in patients with chronic intractable nausea and vomiting from diabetic gastroparesis.6 In this trial, 55 patients with refractory diabetic gastroparesis (5.9 years of diabetic gastroparesis) were given Enterra implants. After surgery, all patients had the stimulator turned on for 6 weeks and then were randomized to groups that had consecutive 3-month crossover periods with the device on or off. After this period, the device was turned on in all patients, and they were followed unblinded for 4.5 months. During the initial 6-week phase with the stimulator turned on, the median reduction in weekly vomiting frequency (WVF) compared with baseline was 57%. There was no significant difference in WVF between patients who had the device turned on or off during the 3-month crossover period. At 1 year, the WVF for all patients was significantly lower than baseline values (median reduction, 68%; p<0.001). One patient had the device removed due to infection; two required surgical intervention for lead-related problems.

McCallum et al (2013) evaluated GES (Enterra system) in patients with chronic vomiting due to idiopathic gastroparesis in a randomized, double-blind crossover trial.7 In this trial, 32 patients with nausea and vomiting associated with idiopathic gastroparesis, unresponsive or intolerant to prokinetic and antiemetic drugs, received Enterra implants and had the device turned on for 6 weeks. Subsequently, 27 of these patients were randomized to have the device turned on or off for 2 consecutive 3-month periods. Twenty- five of these subjects completed the randomized phase; of note, 2 subjects had the device turned on early, 2 subjects had randomization assignment errors, and 1 subject had missing diaries. During the initial 6-week on period, all subjects showed improvements in their WVF, demonstrating a median reduction of 61.2% (5.5 episodes/week) compared with baseline (17.3 episodes/week; p<0.001). During the on-off crossover phase, subjects demonstrated no significant differences between the on and off phases for the study’s primary end point, median WVF (median, 6.4 in on-phase vs 9.8 in off-phase; p=1.0). Among the 19 subjects who completed 12 months of follow-up, there was an 87.1% reduction in median WVF (2 episodes/week) compared with baseline (17.3 episodes/week; p<0.001). Two subjects required surgical intervention for lead migration/dislodgement or neurostimulator migration. 

GES FOR OBESITY
A single RCT has evaluated the use of GES for treating obesity: the SHAPE trial. Shikora et al (2009) reported on a double-blind RCT that assessed GES obesity.8 All 190 trial participants received an implantable gastric stimulator and were randomized to have the stimulator turned on or off. All patients were evaluated monthly, participated in support groups, and reduced their dietary intake by 500 kcal/d. At 12-  month follow-up, there was no statistically significant difference in excess weight loss between the treatment group (weight loss, 11.8%) and the control group (weight loss, 11.7%) using intention-to-treat analysis (p=0.717).

Small case series and uncontrolled prospective trials (2002-2004) have reported positive outcomes for weight loss and maintenance of weight loss along with minimal complications.9-14 However, interpretation of these uncontrolled studies is limited.

SUMMARY OF EVIDENCE
For individuals who have gastroparesis who receive GES, the evidence includes RCTs and systematic reviews. Relevant outcomes are symptoms and treatment-related morbidity. Five crossover RCTs have been published. A 2017 meta-analysis of these 5 RCTs did not find a significant benefit of GES on the severity of symptoms associated with gastroparesis. Patients generally reported improved symptoms at follow-up whether or not the device was turned on, suggesting a placebo effect.

For individuals who have obesity who receive GES, the evidence includes an RCT. Relevant outcomes are change in disease status and treatment-related morbidity. The SHAPE trial did not show significant improvement in weight loss using GES compared with sham stimulation. The evidence is insufficient to determine the effects of the technology on health outcomes.

CLINICAL INPUT FROM PHYSICIAN SPECIALTY SOCIETIES AND ACADEMIC MEDICAL CENTERS
While the various physician specialty societies and academic medical centers may collaborate with and make recommendations during this process, through the provision of appropriate reviewers, input received does not represent an endorsement or position statement by the physician specialty societies or academic medical centers, unless otherwise noted. 

2015 Input
In response to requests, input was received from 1 specialty society (2 reviewers) and 4 academic centers while this policy was under review in 2015. Most respondents agreed that gastric electrical stimulation (GES) should be considered investigational for gastroparesis. There was a lack of consensus whether GES should be considered medically necessary for any specific indication (e.g., diabetic gastroparesis, idiopathic gastroparesis, gastroparesis of postsurgical etiology). The reviewers were not asked about the use of GES for treatment of obesity. 

2009 Input
In response to requests, input was received from 4 academic medical centers (5 reviewers) while this policy was under review in 2009. There was strong agreement among reviewers about the limited data for the use of GES to treat diabetic and idiopathic gastroparesis and about the need for randomized controlled trials. There was strong agreement that GES is investigational in the treatment of obesity.

PRACTICE GUIDELINES AND POSITION STATEMENTS 
National Institute for Health and Care Excellence
The National Institute for Health and Care Excellence (2014) has issued guidance on GES for gastroparesis.15 The Institute made the following recommendations:

12.1    “Current evidence on the efficacy and safety of gastric electrical stimulation for gastroparesis is adequate to support the use of this procedure with normal arrangements for clinical governance, consent, and audit.

12.2… clinicians should inform patients considering gastric electrical stimulation for gastroparesis that some patients do not get any benefit from it. They should also give patients detailed written information about the risk of complications, which can be serious, including the need to remove the device. 

12.3    Patient selection and follow-up should be done in specialist gastroenterology units withexpertise in gastrointestinal motility disorders, and the procedure should only be performed by surgeons working in theseunits.

American College of Gastroenterology
The American College of Gastroenterology published practice guidelines on the management of gastroparesis in 2013.16 The College recommended that:

“GES [gastric electrical stimulation] may be considered for compassionate treatment in patients with refractory symptoms, particularly nausea and vomiting. Symptom severity and gastric emptying have been shown to improve in patients with DG [diabetic gastroparesis], but not in patients with IG [idiopathic gastroparesis] or PSG [postsurgical gastroparesis]. [Conditional recommendation (there is uncertainty about trade-offs), moderate level of evidence (further research would be likely to have an impact on the confidence in the estimate of effect).]”

U.S. PREVENTIVE SERVICES TASK FORCE RECOMMENDATIONS
Not applicable.

ONGOING AND UNPUBLISHED CLINICAL TRIALS
Some currently unpublished trials that might influence this review are listed in Table 1.

Table 1. Summary of Key Trials

NCT No.

Trial Name

Planned Enrollment

Completion Date

Ongoing

NCT02202434a

Dermatome Electrical Stimulation on Individuals With Overweight and Class I Obesity

16

Mar 2018

NCT: national clinical trial.
a  Denotes industry-sponsored or cosponsored trial. 

References: 

  1. Levinthal DJ, Bielefeldt K. Systematic review and meta-analysis: Gastric electrical stimulation for gastroparesis.Auton Neurosci. Jan 2017;202:45-55. PMID 27085627
  2. Chu H, Lin Z, Zhong L, et al. Treatment of high-frequency gastric electrical stimulation for gastroparesis. J Gastroenterol Hepatol. Jun 2012;27(6):1017-1026. PMID 22128901
  3. Lal N, Livemore S, Dunne D, et al. Gastric electrical stimulation with the Enterra System: a systematic review. Gastroenterol Res Pract. Aug 2015;2015:762972. PMID 26246804
  4. Abell T, McCallum R, Hocking M, et al. Gastric electrical stimulation for medically refractory gastroparesis. Gastroenterology. Aug 2003;125(2):421-428. PMID 12891544
  5. U.S. Food and Drug Administration. Summary of Safety and Probable Benefit: Enterra™ Therapy System. 2010; http://www.accessdata.fda.gov/cdrh_docs/pdf/H990014b.pdf. Accessed January 25, 2018.
  6. McCallum RW, Snape W, Brody F, et al. Gastric electrical stimulation with Enterra therapy improves symptoms from diabetic gastroparesis in a prospective study. Clin Gastroenterol Hepatol. Nov 2010;8(11):947-954; quiz e116. PMID 20538073
  7. McCallum RW, Sarosiek I, Parkman HP, et al. Gastric electrical stimulation with Enterra therapy improves symptoms of idiopathic gastroparesis. Neurogastroenterol Motil. Oct 2013;25(10):815-e636. PMID 23895180
  8. Shikora SA, Bergenstal R, Bessler M, et al. Implantable gastric stimulation for the treatment of clinically severe obesity: results of the SHAPE trial. Surg Obes Relat Dis. Jan-Feb 2009;5(1):31-37. PMID 19071066
  9. Cigaina V. Gastric pacing as therapy for morbid obesity: preliminary results. Obes Surg. Apr 2002;12 Suppl 1:12S-16S. PMID 11969102
  10. Cigaina V, Hirschberg AL. Gastric pacing for morbid obesity: plasma levels of gastrointestinal peptides and leptin. Obes Res. Dec 2003;11(12):1456-1462. PMID 14694209
  11. D'Argent J. Gastric electrical stimulation as therapy of morbid obesity: preliminary results from the French study. Obes Surg. Apr 2002;12 Suppl 1:21S-25S. PMID 11969104
  12. De Luca M, Segato G, Busetto L, et al. Progress in implantable gastric stimulation: summary of results of the European multi-center study. Obes Surg. Sep 2004;14 Suppl 1:S33-39. PMID 15479588
  13. Favretti F, De Luca M, Segato G, et al. Treatment of morbid obesity with the Transcend Implantable Gastric Stimulator (IGS): a prospective survey. Obes Surg. May 2004;14(5):666-670. PMID 15186636
  14. Shikora SA. Implantable gastric stimulation for the treatment of severe obesity. Obes Surg. Apr 2004;14(4):545- 548. PMID 15130236
  15. National Institute of Health and Care Excellence. Gastroelectrical stimulation for gastroparesis [IPG489 ]. 2014; https://www.nice.org.uk/guidance/ipg489. Accessed January 25, 2018.
  16. Camilleri M, Parkman HP, Shafi MA, et al. Clinical guideline: management of gastroparesis. Am J Gastroenterol. Jan 2013;108(1):18-37; quiz 38. PMID 23147521

Coding Section

Codes Number Decription
CPT    See Policy Guidelines 
ICD-9 Procedure 86.95 Insertion or replacement of dual array neurostimulator pulse generator
  05.9 Other operations on nervous system
  44.99 Other operation on stomach (one or the other of the above are used for implantation or replacement of peripheral neurostimulator lead, open or laparoscopic approach)
ICD-9 Dignosis   Investigational for all diagnoses
HCPCS   See Policy Guidelines
ICD-10-CM (effective 10/01/15)   Investigationa for all dignoses
  E08.43 Diabetes mellitus due to underlying condition with diabetic autonomic (poly)neuropathy
  E09.43 Drug or chemical induced diabetes mellitus with neurological complications with diabetic autonomic (poly)neuropathy
  E10.43 Type 1 diabetes mellitus with diabetic autonomic (poly)neuropathy
  E11.43 Type 2 diabetes mellitus with diabetic autonomic (poly)neuropathy
  E13.43 Other specified diabetes mellitus with diabetic autonomic (poly)neuropathy
  K31.89 Other diseases of stomach and duodenum
ICD-10-PCS (effective 10/01/15) 0DH60MA, 0DH63MZ, 0DH64MA Surgical, gastrointestinal system, insertion, stomach, stimulation lead, code by approach open, percutaneous or percutaneous endoscopic 
Type of Service Surgery  
Place of Service Inpatient/outpatient  

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive.

This medical policy was developed through consideration of peer-reviewed medical literature generally recognized by the relevant medical community, U.S. FDA approval status, nationally accepted standards of medical practice and accepted standards of medical practice in this community, Blue Cross and Blue Shield Association technology assessment program (TEC) and other non-affiliated technology evaluation centers, reference to federal regulations, other plan medical policies and accredited national guidelines.

"Current Procedural Terminology© American Medical Association.  All Rights Reserved" 

History From 2014 Forward     

10/03/2018 

Annual review, no change to policy intent. Updating background, rationale and references. 

 09/04/2018

Interim review providing medical necessity criteria for some uses of this technology. No other changes to policy intent. 

10/02/2017 

Annual review, no change to policy intent. Updating description, regulatory status, rationale and references. 

10/05/2016 

Annual review, no change to policy intent. Updating background, description, regulatory status, rationale and references. 

10/27/2015 

Annual review, no change to policy intent. Updated coding, added guidelines. 

10/09/2014

Annual review. Updated background, description, rationale and references. Added regulatoring status and coding section. No change to policy intent.


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