Enterra Therapy Research Articles

Impact of Gastric Electrical Stimulation on Economic Burden of Refractory Vomiting: A French Nationwide Multicentre Study

Medico-economic data of patients suffering from chronic nausea and vomiting are lacking. In these patients, gastric electrical stimulation (GES) is an effective, but costly treatment. The aim of this study was to assess the efficacy, safety and medico-economic impact of Enterra therapy in patients with chronic medically refractory nausea and vomiting. Data were collected prospectively from patients with medically refractory nausea and/or vomiting, implanted with an Enterra device and followed for two years. Gastrointestinal quality of life index (GIQLI) score, vomiting frequency, nutritional status and safety were evaluated. Direct and indirect expenditure data were prospectively collected in diaries. Complete clinical data were available for142 patients (60 diabetic, 82 non-diabetic) and medico-economic data were available for 96 patients (36 diabetic, 60 non-diabetic), 24 months after implantation. GIQLI score increased by 12.1 ± 25.0 points (p < .001), with a more significant improvement in non-diabetic than in diabetic patients (+15.8 ± 25.0 points, p < .001 versus 7.3 ± 24.5 points, p = .027, respectively). The proportion of patients vomiting less than once per month increased by 25.5% (p < .001). Hospitalisations, time off work and transport were the main sources of costs. Enterra therapy decreased mean overall healthcare costs from 8873 US$ to 5525 US$ /patient/year (p= .001), representing a saving of 3348 US$ per patient and per year. Savings were greater for diabetic patients (4096 US$ /patient/year) than for non-diabetic patients (2900 US$ /patient/year). Enterra therapy is an effective, safe and cost-effective option for patients with refractory nausea and vomiting. gov Identifier: NCT00903799.

Wisconsin's Enterra Therapy Experience: A multi-institutional review of gastric electrical stimulation for medically refractory gastroparesis

Gastric electrical stimulation is a treatment for symptoms of diabetic or idiopathic gastroparesis refractory to medical management. We sought to evaluate the outcomes of gastric electrical stimulation in the state of Wisconsin during a more than 10-year period. Data were collected prospectively from patients undergoing implantation of the gastric electrical stimulation to initiate gastric electrical stimulation therapy at two Wisconsin institutions from 2005-2017. The Gastroparesis Cardinal Symptom Index was administered during clinical encounters and over the phone preoperatively and postoperatively. A total of 119 patients received gastric electrical stimulation therapy (64 diabetic and 55 idiopathic). All devices were placed laparoscopically. Mean follow-up was 34.1 ± 27.2 months in diabetic and 44.7 ± 26.2 months in idiopathic patients. A total of 18 patients died during the study interval (15.1%). No mortalities were device-related. Diabetics had the greatest rate of mortality (25%; mean interval of 17 ± 3 months post implantation). GCSI scores improved, and prokinetic and narcotic medication use decreased significantly at ≥1 year. Satisfaction scores were high. Gastric electrical stimulation therapy led to the improvement of symptoms of gastroparesis and a better quality of life. Patients were able to decrease the use of prokinetic and narcotic medications and achieve long-term satisfaction. Diabetic patients who develop symptomatic gastroparesis have a high mortality rate over time.

Effectiveness of gastric neurostimulation in patients with gastroparesis.

Background:Patients with gastroparesis have significantly delayed gastric emptying because of impaired nerve function. Gastric neurostimulation from Enterra Therapy provides electrical pulses to the stomach tissue that promotes stimulation of stomach smooth muscle, thereby enhancing gastric emptying. This study evaluates the effectiveness of Enterra Therapy (Medtronic, Minneapolis, Minnesota) in reducing symptoms and improving the quality of life of patients with drug-refractory gastroparesis.Material and Methods:In this study 25 patients underwent minimally invasive, laparoscopic placement of the Enterra Therapy device. Patients were asked to rank their severity of symptoms and quality of life retrospectively by completing the Gastrointestinal Symptoms Rating Scale and Short Form 36 Health Survey with respect to their condition before and 6 months after initiation of Enterra Therapy.Results:Eighteen patients completed the surveys. Patients showed statistically significant improvement in their overall Gastrointestinal Symptoms Rating Scale scores and the mental health component of the Short Form 36 Health Survey.Discussion:Currently, Enterra Therapy has Humanitarian Use Device status, which means that more clinical evidence is needed to prove its effectiveness in gastroparesis. By showing that Enterra Therapy reduces symptoms of gastroparesis and improves patient quality of life, this study contributes to the increasing amount of data supporting its use and potential Food and Drug Administration approval.

Gastric electrical stimulation with Enterra therapy improves symptoms of idiopathic gastroparesis.

BackgroundGastric electrical stimulation (GES) is a therapeutic option for intractable symptoms of gastroparesis (GP). Idiopathic GP (ID-GP) represents a subset of GP. AIMS: A prospective, multicenter, double-blinded, randomized, crossover study to evaluate the safety and efficacy of Enterra GES in the treatment of chronic vomiting in ID-GP.MethodsThirty-two ID-GP subjects (mean age 39; 81% F, mean 7.7 years of GP) were implanted with GES. The stimulator was turned ON for 1½ months followed by double-blind randomization to consecutive 3-month crossover periods with the device either ON or OFF. ON stimulation was followed in unblinded fashion for another 4.5 months. Twenty-five subjects completed the crossover phase and 21 finished 1 year of follow-up.Key ResultsDuring the unblinded ON period, there was a reduction in weekly vomiting frequency (WVF) from baseline (61.2%, P < 0.001). There was a non-significant reduction in WVF between ON vs OFF periods (the primary outcome) with median reduction of 17% (P > 0.10). Seventy-five percent of patients preferred the ON vs OFF period (P = 0.021). At 1 year, WVF remained decreased (median reduction = 87%, P < 0.001), accompanied by improvements in GP symptoms, gastric emptying and days of hospitalization (P < 0.05).Conclusions & Inferences(i) In this prospective study of Enterra GES for ID-GP, there was a reduction in vomiting during the initial ON period; (ii) The double-blind 3-month periods showed a non-significant reduction in vomiting in the ON vs OFF period, the primary outcome variable; (iii) At 12 months with ON stimulation, there was a sustained decrease in vomiting and days of hospitalizations.

Laparoscopic Gastric Electrical Stimulation for Medically Refractory Diabetic and Idiopathic Gastroparesis

BackgroundGastric electrical stimulator (GES) implantation is effective in certain patients with gastroparesis; however, laparotomy is often employed for placement. The aim of this study is to review outcomes of patients who underwent laparoscopic GES therapy for diabetic and idiopathic gastroparesis at a large referral center. MethodsPatients who underwent GES (Enterra Therapy System; Medtronic, Minneapolis, MN) implantation with subsequent interrogation and programming between March 2001 and November 2011 were analyzed. ResultsA total of 113 patients underwent GES placement or revision during the study period. One hundred eleven patients underwent primary GES at our institution, while two patients underwent GES generator revision at our institution. Primary operations were completed laparoscopically in 110 of 111 cases, with one conversion to laparotomy due to severe adhesions. At a mean follow-up of 27 months (1–113), symptom improvement was achieved in 91 patients (80 %) and was similar for both the diabetic and idiopathic subgroups. Need for supplemental nutrition (enteral and/or parental) decreased in both groups. ConclusionsGES placement is feasible using a laparoscopic approach. Medical refractory gastroparesis in the diabetic and idiopathic groups had significant symptom improvement with no difference between the two groups. Need for supplemental nutrition is decreased following GES.

Gastric Neuromodulation With Enterra System for Nausea and Vomiting in Patients With Gastroparesis

Gastric electrical stimulation (GES) has been introduced for treating gastric motility disorders, such as gastroparesis, and obesity. A special method of GES using high frequency-short pulses, called Enterra® Therapy, has been clinically applied to treat nausea and vomiting in patients with gastroparesis. However, its mechanisms are not well understood. General methodologies of GES published in the literature are systematically reviewed and their main effects and application are presented. The major part of this review is focused on Enterra Therapy since this is the only method that has been used clinically. A number of different GES methods have been proposed. GES with long pulses or dual pulses, but not short pulses, are able to alter (enhance or inhibit) such parameters of gastric motility as gastric slow waves and gastric emptying. Synchronized GES has been reported to improve antral contractions. GES with high frequency-short pulses, or Enterra Therapy, is known to improve nausea and vomiting in patients with gastroparesis and has a response rate of 50-70%. Improved gastric accommodation, direct enteric nervous system effects, enhanced vagal activity, and activation of central neurons are believed to be the underlying mechanisms involved in the antiemetic effect of this therapy. GES with high frequency-short pulses effectively reduces nausea and vomiting in patients with gastroparesis. This antiemetic effect could be mediated via enteric, autonomic, and/or central neural mechanisms. Further systematic and controlled studies are needed to improve the efficacy of Enterra Therapy and to understand its mechanisms of action.

OC-061 Gastric electrical stimulation for intractable gastroparesis

IntroductionSevere, drug-unresponsive gastroparesis is a debilitating condition. Treatment with gastric electrical stimulation using Enterra® was granted humanitarian device exemption status by the FDA in 2000. The largest case-series (N=221) reports...

Su1568 Assessment of Muscular Loss After Bariatric Surgery Through Bioimpedancy

Background: Gastroparesis is a disorder of chronic nausea and vomiting that may result in failure to thrive. Etiologies are multifactorial, but most often are classified as diabetic, idiopathic, post-surgical, or medication induced. Several large series have shown efficacy of gastric pacer implantation in certain groups with gastric dysfunction. However, laparotomy is often employed for placement. The aim of this study is to review outcomes of all patients who underwent gastric pacer therapy regardless of etiology.Methods: Patients who underwent gastric pacer (Enterra Therapy System; Medtronic, Minneapolis, MN) implantation with subsequent interrogation and programming between March 2001 and November 2011 were analyzed. Data reviewed included demographics, pre-operative symptoms, operative technique, and post-operative symptom and nutritional improvement. Results: A total of 113 patients underwent gastric pacer placement during the study period. Mean age was 40 years (19-88) and 83% of patients were female. Operations were completed laparoscopically in 110/111 cases, with one conversion to laparotomy due to severe adhesions. Two cases involved pacer revision for battery replacement. Gastroparesis symptoms were present for a mean duration of 4.8 years prior to surgery (1-20). Surgical intervention was only offered for patients with medical refractory diabetic and idiopathic gastroparesis. Prior to implantation, thirty-three patients were on supplemental nutrition (23 on jejunal feeds and 10 on total parental nutrition). There were no operative or immediate peri-operative complications. Battery depletion occurred in 6 patients at a mean interval of 75 months. Pacer malfunction occurred in 4 cases. Two of these cases required removal secondary to lead erosion, 1 underwent conversion to Roux-en Y gastric bypass, and 1 had no therapy. At a mean followup of 24 months, symptom improvement was achieved in 91 patients (80%) and was similar for both the diabetic and idiopathic subgroups. Post-operatively, 15 of 23 patients were able to discontinue supplemental nutrition. BMI increased in both the idiopathic and diabetic cohorts (see Graph 1 and 2). Four patients underwent conversion to laparoscopic Rouxen-Y gastric bypass for persistent poorly controlled symptoms and morbid obesity with associated comorbidities. Symptom control was achieved in 2 of these patients with an overall mean excess weight loss of 22% (8-39) at 7 month follow-up (3-12). Conclusion: Gastric pacer placement is feasible using a laparoscopic approach. Medical refractory gastroparesis in the diabetic and idiopathic groups had significant symptom improvement with no difference between the two groups. Gastric pacing may decrease the need for ongoing supplemental nutrition.

Gastric Stimulation is an Option for Patients With Refractory Cyclical Vomiting Syndrome: One Year Follow up

Background: Post-surgical gastroparesis (PSG) develops in up to 10% of patients who undergo intentional or inadvertent vagotomy and in up to 50% of patients undergoing surgery for gastric outlet obstruction. Dumping syndrome is also a possible outcome from these surgeries. Aim: The aims of this study were to: 1) describe the clinical features of patients presenting with PSG symptoms; 2) identify surgeries associated with PSG; 3) distinguish PSG from a possible Dumping Syndrome. Methods: Medical and surgical history, symptoms assessment (PAGI-SYM,PAGI -QOL, Beck Depression Inventory (BDI), State-Trait Anxiety Inventory (STAI), and standardized 4-hour radionuclide gastric emptying test (GET) on patients with at least 12 weeks of gastroparesis (GP) symptoms were performed. Data were analyzed from the ongoing NIDDK GP Registry. All results are presented as percent or mean ± SD. Results: Out of 571 patients, 23 (4 %) qualified as having PSG symptoms. Of these 19 (83%) were F; mean age 48.0±13.2 years; mean BMI 24.7 ±6.5 (61% had a BMI ≤ 24). The mean symptoms duration was 6 years and onset of GP symptoms was associated with the following surgeries: Nissen Fundoplication (52%), partial gastric resection (22%); myotomy or esophago-gastrectomy (9% each); and stomach stapling and vagotomy (4% each). 52% of patients had been hospitalized in the past year and nausea with abdominal pain was the major indication for 78% of these admissions. 52% were on prokinetics, 78% on antiemetics, 78% on PPI / H2 blockers and 26% were on narcotics. None of the patients underwent Botox and 1 had Enterra therapy. The results of GET separated patients with PSG symptoms into: Group A-17(74%) with delayed GETmean value of 43.3 %± 26% retention at 4h (min-14; max -100% ), and 9 (53%) of them had severely delayed gastric emptying (>35% retention at 4h) and Group B6 (26%) without delayed GET, with a mean of 5.3% food retention at 4 h (min-1, max-7%) and with 2 (33%) of these patients meeting the criterion for Dumping Syndrome with ≤30% retention at1h. Overall, the highest mean PAGI-SYM score was for nausea 3.7 ± 1.3(max 5) and early satiety at 3.7±1.3. 17% of all studied patients had severe depression by BDI, 30% had severe STAI score. The average PAGI-QOL score was 2.7±1.1; with the poorest QOL for the diet sub-score (1.6±1.2). There were no statistical differences in symptoms or psychological parameters between the two groups. Conclusions: 1) In the setting of post-gastric and -esophageal surgeries, symptoms associated with delayed, normal or rapid emptying of the stomach are clinically indistinguishable and only GET could guide further medical and therapeutic approaches 2) Nissen Fundoplication is now the major surgery associated with PSG symptoms and could be attributed to “accidental” vagal nerve injury during surgery.

Symptom Relief After Gastric Electric Stimulation Treatment (Enterra Therapy) is Related to Percent Change in Gastric Retention in Diabetic but Not Post-Surgical or Idiopathic Gastroparesis : A Sensitivity Analysis With Logistic Regression Models

G A A b st ra ct s may induce abnormal gastric slow wave patterns, however these patterns are poorly understood, because of the incomplete detail provided by previous recording methods (EGG / sparse-electrodes). In this study, we describe gastroparetic slow wave patterns in highresolution (HR) spatiotemporal detail. Methods: Patients with diabetic (n=10) and idiopathic (n=2) gastroparesis undergoing gastric stimulator implantation were enrolled (median age 41 yrs, mean ‘total symptom score’ 17±2 out of 20, mean 4-hr gastric emptying 28±19%). HR electrical mapping was performed using flexible arrays (256 electrodes; 4 mm spacing) placed over the anterior corpus and/or corpus-antrum border immediately after laparotomy. Propagation patterns were quantified by isochronal mapping. Results were compared to data from 12 patients with no known stomach pathology undergoing routine surgery, who were assessed in the same manner. Mean ± SEM are reported. Results: Slow wave propagation was exclusively normal in all controls (29 recordings; mean duration 4.65 min; freq. 2.8±0.3 c/min), whereas a range of abnormal propagation patterns were observed in 11/12 gastroparetics (21 recordings; mean duration 7.3 min). Diabetics: Abnormalities comprised incomplete conduction blocks (n=6 recordings; 3.0±0.2 c/min), corpus ectopic pacemakers (n=6; 3.5±0.3 c/min), antral focal events (n=2), and complete conduction block with escape (n=1; 2.2 c/ min). There was also one instance each of regular antral tachygastria (4 c/min), and disorganized / fibrillation-type behavior in the corpus with multiple wavelets propagating (n=1; 4.9 c/min). Wavefront collisions and retrograde propagation were each recorded in 5 patients. Idiopathics: Both patients demonstrated highly disorganized propagation with incomplete conduction blocks, competing ectopics, retrograde propagation, and colliding wavefronts. Conclusion: A diverse range of slow wave initiation and conduction abnormalities were revealed by HR mapping in patients with gastroparesis. Several dysrhythmic mechanisms are described here for the first time in humans. These abnormalities were spatially complex, meaning they might go undetected by lower resolution tests such as EGG. The clinical significance of these findings needs to be determined.

Gastric Electrical Stimulation Improves Outcomes of Patients With Gastroparesis for up to 10 Years

We assessed the long-term clinical outcomes of gastric electrical stimulation (GES) therapy with Enterra (Enterra Therapy System; Medtronic, Minneapolis, MN) in a large cohort of patients with severe gastroparesis. Gastroparesis patients (n=221; 142 diabetic, 48 idiopathic, and 31 postsurgical) treated with Enterra (Medtronic) for 1-11 years were retrospectively assessed; 188 had follow-up visits and data were collected for at least 1 year (mean 56 months, range 12-131 months). Total symptom scores (TSSs), gastric emptying, nutritional status, weight, hospitalizations, use of prokinetic and/or antiemetic medications, levels of HbA1c levels (in diabetic patients), and adverse events were evaluated at the beginning of the study (baseline) and during the follow-up period. TSS, hospitalization days, and use of medications were significantly reduced among all patients (P<.05). More patients with diabetic (58%) and postsurgical gastroparesis (53%) had a greater than 50% reduction in TSS than those with idiopathic disease (48%; P=.32). Weight significantly increased among all groups, and 89% of J-tubes could be removed. At end of the follow-up period, all etiological groups had similar, abnormal delays in mean gastric retention. Thirteen patients (7%) had their devices removed because of infection at the pulse generator site. GES therapy significantly improved subjective and objective parameters in patients with severe gastroparesis; efficacy was sustained for up to 10 years and was accompanied by good safety and tolerance profiles. Patients with diabetic or postsurgical gastroparesis benefited more than those with idiopathic disease.

Gastric Electrical Stimulation With Enterra Therapy Improves Symptoms From Diabetic Gastroparesis in a Prospective Study

Gastric electrical stimulation (GES) treats refractory gastroparesis by delivering electric current, via electrodes, to gastric smooth muscle. Enterra therapy (Medtronic, Inc, Minneapolis, MN) uses an implantable neurostimulator with a high-frequency, low-energy output. We performed a controlled, multicenter, prospective study to evaluate the safety and efficacy of Enterra therapy in patients with chronic intractable nausea and vomiting from diabetic gastroparesis (DGP). Patients with refractory DGP (n = 55; mean age, 38 y; 66% female, 5.9 years of DGP) were given implants of the Enterra gastric stimulation system. After surgery, all patients had the stimulator turned on for 6 weeks and then they randomly were assigned to groups that had consecutive 3-month, cross-over periods with the device on or off. After this period, the device was turned on in all patients and they were followed up, unblinded, for 4.5 months. The median reduction in weekly vomiting frequency (WVF) at 6 weeks, compared with baseline, was 57% (P < .001). There was no difference in WVF between patients who had the device turned on or off during the cross-over period (median reduction, 0%; P = .215). At 1 year, the WVF of all patients was significantly lower than baseline values (median reduction, 67.8%; P < .001). Patients also had significant improvements in total symptom score, gastric emptying, quality of life, and median days in the hospital. In patients with intractable DGP, 6 weeks of GES therapy with Enterra significantly reduced vomiting and gastroparetic symptoms. Patients had improvements in subjective and objective parameters with chronic stimulation after 12 months of GES, compared with baseline.

Enterra® Therapy: gastric neurostimulator for gastroparesis

Gastroparesis is a chronic disorder of gastric motility characterized by delayed gastric empting in the absence of mechanical obstruction, which can lead to symptoms of nausea, vomiting, bloating, abdominal pain, postprandial fullness and weight loss. Although there are many etiologies, the primary causes are diabetes or are idiopathic. The mainstay of treatment is dietary and drug therapies. However, many patients will continue to suffer intractable symptoms despite these treatments. Gastric neurostimulation with the Enterra® Therapy system has been approved for use under the Humanitarian Device Exemption by the US FDA. The device produces pulses of electrical stimulation that are delivered to the stomach continuously. One randomized clinical trial and multiple nonrandomized unblinded clinical trials and case series have documented improvement of symptoms in intractable diabetic and idiopathic gastroparesis. The purpose of this article is to introduce the Enterra Therapy gastric neurostimulator. Gastroparesis and its pathophysiology will be discussed in this clinical context to enhance the understanding of the device and its development. We will analyze the device in detail, its placement and the results of studies evaluating its efficacy.

What Are the Optional Parameters of the Enterra Gastric Electrical Stimulation to Achieve Long Term Symptom Control in Gastroparetic Patients?

Purpose: Gastric electrical stimulation (GES) with Enterra Therapy (ET) has been proven as a safe and effective treatment option in patients with medically refractory gastroparesis (GP). Limited data is available regarding the electrical parameters and settings utilized that can result in successful long term out-come for GES therapy. To analyze the differences in stimulation parameters from the time of initiation of neuromodulation to the last follow-up (up to 10 years) in three, etiologically distinct groups of GP who were implanted at one center, and followed up by one team of investigators. Methods: 221 patients diagnosed with GP (164 F) mean age 38 (18-70) [142 diabetics (DM), 48 idiopathics (ID), 31 post-surgical (PS)] were implanted with GES at our site between 1998-2008. Baseline stimulation settings were as follows: frequency- 14 Hz, current (I) 5 mA, pulse width 330 μsec, and 0.1 sec ON, 5.0 sec OFF. At each follow-up visit (1-2 per year), GP symptoms were evaluated and stimulation parameters reviewed. Standardized protocol was used to adjust stimulation settings based on impedance (R) reading and symptom control. Results: The programming information (median readings) from 185 patients (119 DM, 39ID, 27 PS) for comparing baseline (programmed at surgery) to last follow-up (mean 55 months; range 12-131) is in the Table. 60%DM, 49%ID, 59%PS achieved at least 50% reduction in their GP symptoms, and 32%, 23%, 22%, respectively, required no changes in their settings to reach this outcome. Voltage adjustment with subsequent change in current ≥10 mA took place in 10% of DM, 15% of ID, and 14% of PS. Four DM, 3 ID and 1 PS patient utilized 1-2 sec ON and 3-4 sec OFF. The frequency of stimulation was not changed in any of our Enterra patients. Four patients needed battery replacements during follow-up (between 6-7 years after initiating Enterra). Interestingly, the baseline voltage in DM was significantly lower than in ID (P<0.05) but similar to voltage in PS group.TableConclusion: 1. During long term follow-up of GES patients, stimulation parameters were changed resulting in a significant voltage increase, which was similar in the 3 groups DM, ID and PS. 2. Better symptom improvement among patients with DM and PS etiologies could be related to their lower baseline voltage and follow-up resistance values. 3. Our data suggests that a “conservative” approach to changing parameters during interrogation of the gastric stimulator, based on GI symptoms status results in effective clinical outcomes. Disclosure: Dr Irene Sarosiek - Consultant: Medtronic, Inc. Dr McCallum - Consultant: Medtronic, Inc.

T1811 Changes in Brain Processing Following Acquired Obesity

were performed at the completion of the experiments to assess possible tissue damages in the liver. Result: A) The parameters (train on-time of 0.1s, off-time of 4.9s, 14Hz, 0.3ms, 4mA) used in the Enterra Therapy for treating nausea and vomiting was found to be effective in reducing blood glucose. In the normal rats, HES decreased the levels of blood glucose by 27%-31% at time points 60', 75' and 90' compared with sham HES (P<0.05) in the oral glucose test. B) In the type-I diabetic rats, 3-hr HES resulted in a significant reduction in blood glucose in the fasting state (491.3±7.3 mg/dl vs. 543.1±17.9 mg/dl, P<0.02). In the normal fed condition, 8-hr HES but not sham-HES reduced blood glucose by 23% (417.1±15.1 mg/dl vs. 321.5±16.8 mg/dl, p<0.001). The amount of food intake was not altered by HES,indicating that the reduced blood glucose was not attributed to a reduction in food intake. C) Similarly, in the type-II diabetic rats, 3-hr HES but not sham-HES reduced fasting blood glucose by 20%. Eight hour HES also significantly reduced the blood glucose level by 14% during regular feeding. D) No adverse events were reported in any rats during HES. Histopathological analyses revealed no tissue damages in the liver. Conclusions: Chronic HES is feasibly and safe. HES is capable of reducing both fasting and fed blood glucose in normal, type-I and type-II diabetic rats. Further studies are warranted to optimize stimulation parameters and locations to make HES more efficacious.

Quality of Life and Symptomatic Response to Gastric Neurostimulation for Gastroparesis

BackgroundGastroparesis can be a difficult problem with patients suffering from nausea, vomiting, bloating, and pain intractable to medical management. Gastric neurostimulation has been developed as an adjunctive treatment for patients with diabetic and idiopathic gastroparesis unresponsive to pharmacologic and dietary treatment. The purpose of this study is to report symptomatic and quality-of-life response to gastric neurostimulation. MethodsThis study was approved by the institutional review board, and patients had informed consent. The gastric neurostimulation device (Enterra therapy, Medtronic, Inc., Minneapolis, MN, USA) is approved by the Food and Drug Administration under the Humanitarian Device Exemption. Candidates for placement were patients with either idiopathic or diabetic gastroparesis who had symptomatic failure to dietary changes and to prokinetic and antiemetic drugs. Before placement, the patients’ symptoms were recorded, and patients completed the Gastrointestinal Symptom Rating Scale (GSRS, three domains: dyspeptic syndrome, indigestion syndrome, and bowel dysfunction syndrome) and the Short Form-36 (SF-36, eight domains: physical functioning, role-physical, role-emotional, bodily pain, vitality, mental health, social functioning, general health, plus a health transition item). The device was surgically placed using a hybrid laparoscopic/open technique. Patients were followed and adjustments made on the device until satisfactory symptom control was achieved. At that time, patients completed both the GSRS and SF-36, and comparisons were made to preoperative values. ResultsForty-two patients had the device placed, 29 women, aged 41 (SD +14) years, 24 diabetic patients, 17 idiopathic patients, one postgastrectomy patient. Median follow-up was 12 months (range 1–42 months). There was a 2% immediate postoperative morbidity rate and 7% long-term morbidity rate (device extrusion). Thirty-one patients (74%) responded to gastric neurostimulation of variable degrees. Eleven patients had no response or had worsening symptoms. Of the patients who responded, there were statistically significant improvements in all three domains of the GSRS. Median scores (with interquartile ranges): dyspeptic syndrome, 9 (7–11.5) to 4 (2.5–6), p = 0.02; indigestion syndrome, 5 (2–7) to 4 (0–5), p = 0.05; bowel dysfunction syndrome, 3 (2–3) to 1 (0–1), p = 0.01. In the SF-36, there were statistically significant improvement in the health transition item, 4 (4–5) to 1.5 (1–3), p = 0.01; and social functioning domain, 25 (12.5–62.5) to 75 (50–87.5), p = 0.03. ConclusionsThree quarters of gastroparesis patients responded to gastric neurostimulation to variable degrees. Gastrointestinal-specific symptoms are improved in responders. Patients felt that there health and social functioning (SF) improved, although there was no significant difference in the other domains. These results are encouraging considering that these patients had intractable symptoms with no other effective treatments available.

Small Case Series of Gastric Stimulation for the Management of Transplant-Induced Gastroparesis

Gastroparesis is a recognized complication following organ transplantation with incidences reported between 24 and 83%. Gastroparesis can complicate medical management in these patients leading to the inability to take medications and possibly chronic transplant rejection. Gastric electrical stimulation (GES) has been shown in both controlled and uncontrolled studies to reduce the frequency of nausea and vomiting and lead to weight gain in patients with gastroparesis refractory to standard medical treatment; however, there is little evidence to support the use of GES in transplant recipients. The goal was to evaluate the response of transplant patients with gastroparesis to GES and compare to nontransplant recipients. A questionnaire consisting of 11 questions was administered to investigate symptoms. Patients were asked to score these symptoms before and after surgery using a 0-5 Likert scale. Thirteen consecutive patients underwent placement of the Enterra (Medtronic, Minneapolis, MN) device with a mean follow-up of 12 +/- 6.1 months. All three transplant patients (100%) reported an improvement in quality of life. Similarly, transplant patients were as likely as the diabetic or idiopathic patients to demonstrate improvements in symptoms of nausea, vomiting, and retching and prandial symptoms following Enterra therapy. In fact, transplant patients reported improvement in appetite and bloating symptoms more frequently than diabetics (P = 0.055 and P = 0.037, respectively). Posttransplantation gastroparesis responds to therapy with Enterra GES as well as in patients with idiopathic or diabetic gastroparesis. Enterra therapy should be prospectively investigated in this population of patients.

T1032 The Incidence, Spectrum and Management of Complications Encountered During 10 Years Experience with Enterra Therapy for the Treatment of Severe Gastroparesis

T1032 The Incidence, Spectrum and Management of Complications Encountered During 10 Years Experience with Enterra Therapy for the Treatment of Severe Gastroparesis

Electrical stimulation for gastroparesis

Gastroparesis is a disabling, and sometimes fatal, disease that often does not respond to medical treatment. This single-surgeon prospective study examines the safety and 6-month efficacy of electrical stimulation for the treatment of gastroparesis. Sixteen patients with medically refractory gastroparesis underwent laparoscopic implantation of an electrical stimulator device (Enterra Therapy, Medtronic, Minneapolis, MN, USA) consisting of a subcutaneous stimulator and two gastric wall leads. Gastric emptying scans (GES) confirmed the diagnosis of gastroparesis. Patients were evaluated preoperatively using a self-administered GI symptomatology questionnaire and RAND 36 Health Survey. Once patients were >6-months from implantation, a repeat GES was obtained and patients completed a postoperative GI symptomatology questionnaire and RAND 36 Health Survey. Ten of 16 patients in this case series were >6-months from implantation. One was lost to follow-up. An F-test was used to establish equality of standard deviations between the 16 patients evaluated preoperatively and the subset of 10 patients evaluated postoperatively. A Student's t-test was used to evaluate the significance of differences in pre- and postoperative results. Average operating time was 117 min with no intraoperative complications. The majority of patients were discharged on postoperative day 1. There were two complications in the postoperative period. Patients experienced a significant decrease in nausea and vomiting as measured by the GI symptomatology questionnaire. Half of all patients no longer required gastric prokinetic medications and there was a subjective reduction of pyrosis, early satiety, and epigastric pain. A significant increase in quality of life as measured by the RAND 36 Health Survey was seen, and six of eight patients no longer demonstrated gastroparesis on GES. Laparoscopic implantation of an electrical stimulation device is a safe and effective treatment by subjective and objective standards for the management of medically refractory gastroparesis.