Gastric Pacing for the Treatment of Morbidly Obese Patients

by V. Cigaina, A. Saggioro, L. Gracco, L. Pivotto, G. Tamburrano

Background: A novel method to treat morbid obesity is presented – gastric electrical pacing. Follow-ing animal research, human investigation in a total of 24 patients in three cohorts began in 1995.

Methods : Morbidly obese subjects (BMI 40) received electrical stimulation devices in 1995/6 (n=4), 1998 (n=10) and 2000 (n=10). Electrodes were positioned intramuscularly on the anterior gastric wall at the lesser curvature. BMI = body mass index; %EBL = % excess BMI (>25) lost.

Results: Patients reported satiety for food with less food.The 2 patients from the first study followed for >5 years have 38 and 67 %EBL. In the second study, every patient lost weight.At 36 months followup, the mean %EBL was 24±10 SD (n=10).

Conclusions: Implantable gastric pacing is a safe procedure and causes changes in eating habits in morbidly obese humans,resulting in decreased food intake and weight loss.


Implantable Gastric Stimulation for the Treatment of Morbid Obesity

by Valerio Cigaina, MD

Background: The implantable gastric stimulator (IGS), a pacemaker-like device, has been found to be safe and effective to induce and maintain weight loss.We present our experience with 20 morbidly obese patients.

Methods: Between September 20 and November 22, 2002, 20 patients (F/M 12/8), mean age 40.3 years (23-62) underwent IGS implantation. Mean BMI was 40.9(33.9-48.2), mean weight 115.0 kg (87.0-137.0) and mean excess weight (EW) 51.3 kg (35.6-70.1). Co-morbitidies were: 3 cases of hypertension, 1 diabetes, 1 dislipidemia and 1 depression. Mean operative time was 58.5 min (37-85). The IGS was actived 30 days after implantation. Patients were advised to follow a low calorie diet and behavior modification (to avoid fat and to ingest more liquids during meals, to chew slowly, to eat vegetables before main meals, and to perform exercise daily).

Results: Mean ± standard error percent excess weight loss (%EWL) was: 10.6±1.8 at 1 month; 15.0±2.3 at 2 months; 16.6±2.6 at 3 months; 18.1±3.5 at 4 months; 15.5±3.5 at 6 months; 18.9±3.5 at 8 months; and 23.8±5.0 at 10 months. There were no intra-operative surgical or long-term complications. There were 3 intra-operative gastric penetrations, observed by gastroscopy, without sequelae. One patient with hypertension ceased his medical therapy at the 4th month.

Conclusion: IGS can be implanted laparoscopicall y with minimal perioperative complications. The observed weight loss is comparable to other noninvasive procedures. If weight loss is maintained, IGS could be considered as a first choice therapy in the treatment of morbid obesity in selected patients.


Long-Term Follow-Up of Gastric Stimulation for Obesity: The Mestre 8-Year Experience

by Valerio Cigaina, MD

Background: 10 years experience with gastric stimulation demonstrates promise, in particular because weight loss is achieved and maintained without drugs or side-effects.We report on a total of 65 patients who have received an Implantable Gastric Stimulator (IGS®) since 1995.

Methods: 65 patients have received an IGS and were monitored for weight loss as well as co-morbidities. Gastroesophageal Reflux Disease (GERD) was assessed by endoscopy and symptoms were evaluated. An acute Holter study was performed on 4 patients pre-implant, post-implant, and post-activation of the IGS. Oral glucose tolerance test (OGTT) using a 76-g bolus of oral dextrose was done before device implantation and after-activation. Gastric emptying was tested on 19 of the patients using Tc99, both pre-implant and 6 months post-implant. Resting Energy Expenditure (REE) was studied in 15 patients using indirect calorimetry at 3 different points in time: pre-activation, 6 months post-implant, and 12 months post-implant. Blood pressure was measured using an electronic wrist device to overcome potential artifacts due to arm fat.

Results: IGS patients lost significant weight with no side-effects and experienced significant and rapid improvements in blood pressure. Almost all of the GERD patients reported symptomatic relief during gastric pacing. OGTT demonstrated improved response to insulin at 7 months post-stimulation. The gastric emptying and REE tests were less conclusive, to a great extent because of the small sub-population of patients.

Conclusion: While the exact mechanisms of gastric stimulation remain incompletely understood, it appears that the implantation of an IGS is associated with weight loss, an improvement (decrease) in blood pressure in hypertensive patients, and a reduction or elimination of symptoms in those who had GERD. This promising weight loss therapy warrants further study, in particular because of its intriguing results with co-morbidities.


Gastric Pacing for Morbid Obesity: Plasma Levels of Gastrointestinal Peptides and Leptin

by Valerio Cigaina and Angelica L. Hirschberg

Gastric pacing for morbid obesity: plasma levels of gastrointestinal peptides and leptin. Obes Res. 2003;11: 1456–1462. Objective: A gastric pacemaker has been developed to treat morbid obesity. Patients experience increased satiety, the ability to reduce food intake, and a resultant weight loss. However, the mechanism behind the changed eating behavior in paced patients is still under investigation.

Research Methods and Procedures: This study was performed on 11 morbidly obese patients (mean BMI, 46.0 kg/m2 ) treated with gastric pacing. The peripheral blood levels of satiety signals of cholecystokinin (CCK), somatostatin, glucagon-like peptide-1 (GLP-1), and leptin were studied 1 month before gastric pacer implantation, 1 month after implantation, and 6 months after activation of electrical stimulation. Blood samples were drawn 12 hours after fasting and in response to a hypocaloric meal (270 kcal). Patients were followed monthly for vital signs and weight level.

Results: Gastric pacing resulted in a significant weight loss of a mean of 10.4 kg (4.4 BMI units). No negative side effects or complications were observed during the treatment. After activation of the pacemaker, meal-related response of CCK and somatostatin and basal levels of GLP-1 and leptin were significantly reduced (p  0.05) compared with the tests before gastric pacing. The weight loss correlated significantly with a decrease of leptin levels (R 0.79, p  0.01).

Discussion: Gastric pacing is a novel and promising therapy for morbid obesity. Activation of the gastric pacer was associated with a decrease in plasma levels of CCK, somatostatin, GLP-1, and leptin. More studies are necessary to elucidate the correlations between satiety, weight loss, and digestive neuro-hormone changes.


Pacing the Stomach: Our Experience on Two Obese Patient Populations

by V. Cigaina, A. Saggioro

Background: After successful animal studies in 1992, the first human implant of a gastric pacemaker to modify the gastric environment behavior and treat morbid obesity was performed in 1995. A cohort of 10 patients started to be followed with longterm data collected from 1998. A further group of 10 patients were implanted during 2000. Purpose: Evaluate the safety (in terms of reported complications) and effectiveness (in terms of weight loss) of gastric stimulation in the morbidly obese population.

Methods: 20 subjects, between 41 and 69 of BMI, 4 males and 16 females, age ranging between 23 to 62 years, were implanted with a second generation Implantable Gastric Stimulator (IGS™), Transcend ™, supplied by Transneuronix Inc., New Jersey, USA. 13 of these subjects received a new pacer as a replacement for a previous device. The pacer was placed in the subcutaneous abdominal fat over the muscular fascia and connected to a bipolar lead, which was placed under general anesthesia and by video-laparoscopy, in the lesser curvature of the gastric antral wall. The pacer was activated thirty days after the implant. The patients were discouraged to drink alcohol and sweet beverages. Monthly clinical controls were obtained for the first 6 months period, and every three months thereafter.

Results: The first patient, of 1995 trial, lost 90% of her excess body mass at 21 months after the implant. After pacer replacement she reached 60-70% of Excess Body Mass Loss (EBL) and maintained it till the 52nd month, when she had lead dislodgment.

There have been no deaths or other major complications.The main feeling reported from all the patient population during the gastric pacing was an early and increased satiety, which reinforced the patients’ efforts for food intake reduction. Despite the electrical stimulation of the stomach, no peptic related disorders or gastrointestinal side effects were reported. GERD was improved after stimulation. There have been 6 intra-operative gastric penetrations, as noted on operative gastroscopy without any clinical sequellae. Of the 13 replacements, six had lead dislodgments (two partial, four total), which occurred between the first and fourth months. This was probably due to inadequate tine length on the leads. Subsequently, after those events, all leads were fixed using sutures and only one partial dislocation was reported.

Conclusions: Long-term studies continue to show that gastric pacing can be a safe and effective procedure. A metabolic change or a new standpoint in the brain-gut axis is hypothesized, and studies regarding mechanisms of weight loss due to gastric pacing are progressing.


Treatment of Obesity with the Transcend® Implantable Gastric Stimulator: MULTI-CENTER STUDY

by V. Cigaina, J. Dargent, M. Belachew, L. Melissas, K. Miller, F. Favretti, F. Horber


Laparoscopic gastric pacing (LGP) is a minimally invasive technique that is performed for the treatment of obesity. LGP was first developed in the early 1990s for gastroparesis, and was also found to be effective in the treatment of obesity. The application of electrical current to the stomach alters gastric myoelectrical activity, without any changes in the gastrointestinal anatomy. The exact mechanism of LGP remains to be elucidated. However, potential mechanisms to assess the success of LGP might include an increased feeling of satiety as the result of reduced gastric emptying, or changes in neuropeptide levels.

LGP is a minimally invasive technique that is potentially safe and effective for treating obesity; nevertheless, the selection of patients for gastric stimulation therapy appears to be an important determinant of the outcome of this treatment.

This article reviews the current status, potential mechanisms of action, operating techniques, complications, postoperative management and outcomes, and possible future applications of gastric stimulation in obesity management.


Gastric Pacing and Morbid Obesity: The Role of the Autonomic Nervous System (ANS)

by V. Cigaina, R. Bacci


Gastric stimulation has been shown to be a safe and effective therapy for morbid obesity in several clinical studies from 1995. This new therapy model is not mutilating for the digestive system, has not the common risks of bariatric surgery, and has not side effects. Clinical reports suggest, for the( IGS®), a neuromodulation activity of the brain-gut axis.

The gastric wall has, neurologically, a milestone role in the brain-gut autonomic system.

A clinical study was designed in order to investigate correlations between gastric pacing, the Autonomic Nervous System (ANS) and the metabolic syndrome in obesity.


MedAutonomic Brain NeuroModulator: A Brief Summary of the Fundamental Science and Research

by Valerio Cigaina MD, Dr. Paolo Fabris, John Gonzales PhD

The purpose of this paper is to provide an overview of the science and research that lies behind MedAutonomic’s pathbreaking device, the Brain NeuroModulator (BNM). Our focus is to establish that there is a body of evidence that strongly supports our approach to addressing functional diseases related to the metabolic syndrome and an imbalance in the autonomic nervous system.

A functional disease becomes a pathology of the organ if left untreated for a long period of time. For example, if GERD is not corrected then the esophagus will be damaged. If hyperglycemia is not corrected, the atherosclerosis organ damage from diabetes will become systemic. The same idea holds for diastolic hypertension and overeating in the obese.


Upper Endoscopic Procedure for the Gastric Brain Neuro-Modulator Implant: First Experience

by Valerio Cigaina*, Alfredo Saggioro** , Paolo Fabris***

*Surgical Department - Umberto I Hospital - Venezia-Mestre – ITALY

**Dietetic and Clinical Nutrition Unit c/o Gastrointestinal Department. Umberto I Hospital Venezia-Mestre Italy

***Engineering Milan Company


We are evaluating the feasibility of an upper endoscopic outpatient procedure to implant a small bioelectric device, a brain neuro-modulator (BNM), in the thickness of the gastric wall.

The BNM has been designed in order to tune the sympathetic/parasympathetic balance of the autonomic nervous system (ANS). This adjustment is relevant to addressing the metabolic syndrome and/or functional disorders1.