Gastric Peristalsis Control by Mono Situ Electrical Stimulation: a Preliminary Study

Closed-loop gastric electrical stimulation versus laparoscopic adjustable gastric band for the treatment of obesity: a randomized 12-month multicenter study

OBJECTIVE

To compare the weight loss, change in quality of life (QOL) and safety of closed-loop gastric electrical stimulation (CLGES) versus adjustable gastric band (LAGB) in the treatment of obesity.

METHODS

This multicenter, randomized, non-inferiority trial randomly assigned the patients in a 2:1 ratio to laparoscopic CLGES versus LAGB and followed them for 1 year. We enrolled 210 patients, of whom 50 were withdrawn preoperatively. Among 160 remaining patients (mean age=39±11 years; 75% women; mean body mass index=43±6 kg m^-2) 106 received CLGES and 54 received LAGB. The first primary end point was non-inferiority of CLGES versus LAGB, ascertained by the proportion of patients who, at 1 year, fulfilled: (a) a ⩾20% excess weight loss (EWL); (b) no major device- or procedure-related adverse event (AE); and (c) no major, adverse change in QOL. Furthermore, ⩾50% of patients had to reach ⩾25% EWL. The incidence and seriousness of all AE were analyzed and compared using Mann-Whitney's U-test.

RESULTS

At 1 year, the proportions of patients who reached all components of the primary study end point were 66.7 and 73.0% for the LAGB and CLGES group, respectively, with a difference of -6.3% and an upper 95% CI of 7.2%, less than the predetermined 10% margin for confirming the non-inferiority of CLGES. The second primary end point was also met, as 61.3% of patients in the CLGES group reached ⩾25% EWL (lower 95% CI=52.0%; P<0.01). QOL improved significantly and similarly in both groups. AE were significantly fewer and less severe in the CLGES than in the LAGB group (P<0.001).

CONCLUSIONS AND RELEVANCE

This randomized study confirmed the non-inferiority of CLGES compared with LAGB based on the predetermined composite end point. CLGES was associated with significantly fewer major AE.

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

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(R)) 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 stimulation for weight loss

The prevalence of obesity is growing to epidemic proportions, and there is clearly a need for minimally invasive therapies with few adverse effects that allow for sustained weight loss. Behavior and lifestyle therapy are safe treatments for obesity in the short term, but the durability of the weight loss is limited. Although promising obesity drugs are in development, the currently available drugs lack efficacy or have unacceptable side effects. Surgery leads to long-term weight loss, but it is associated with morbidity and mortality. Gastric electrical stimulation (GES) has received increasing attention as a potential tool for treating obesity and gastrointestinal dysmotility disorders. GES is a promising, minimally invasive, safe, and effective method for treating obesity. External gastric pacing is aimed at alteration of the motility of the gastrointestinal tract in a way that will alter absorption due to alteration of transit time. In addition, data from animal models and preliminary data from human trials suggest a role for the gut-brain axis in the mechanism of GES. This may involve alteration of secretion of hormones associated with hunger or satiety. Patient selection for gastric stimulation therapy seems to be an important determinant of the treatment’s outcome. Here, we review the current status, potential mechanisms of action, and possible future applications of gastric stimulation for obesity.

Implantable gastric stimulator does not prevent the increase in plasma ghrelin levels that occurs with weight loss

The SHAPE (Screened Health Assessment and Pacer Evaluation) trial was a 24 month randomized multicenter placebo-controlled study to determine the efficacy of an implantable gastric stimulator (IGS) for weight loss. This report is an investigator-initiated sub-study at one site designed to assess whether IGS affects plasma levels of ghrelin and peptide YY (PYY). The device was implanted in all subjects but was activated in the TREATMENT group (n = 7, BMI = 41.5 ± 2.0 kg/m2) and remained inactive in the CONTROL (n = 6, BMI = 39.5 ± 1.7 kg/m2) during the first 12 months. IGS was activated in both groups during months 12-24. Fasting venous blood was drawn at months 0, 12, and 24 and an oral glucose tolerance test (OGTT) was performed at month 12. Although there was no difference in weight loss at 6 months (

CONTROL

-6.6 ± 1.5% vs.

TREATMENT

-6.2 ± 1.4%), at 24 months the CONTROL group exhibited weight gain from baseline (+2.2 ± 1.5%) that was significantly different from the weight loss in the TREATMENT group (-1.9 ± 1.4%; P < 0.05). At 12 months, fasting ghrelin was significantly increased (P < 0.05) in the TREATMENT group (285 ± 35 to 336 ± 35 pg/ml; weight change, -4.9 ± 1.4%), but not in the CONTROL (211 ± 36 to 208 ± 35 pg/ml; weight change, -3.4 ± 1.5%). No significant change was observed in postprandial suppression of plasma ghrelin or in fasting and postprandial PYY levels. In conclusion, IGS does not prevent the increase in fasting plasma ghrelin levels associated with weight loss. Further studies are needed to determine whether changes in technology can improve weight loss and maintenance, perhaps using gut hormones as biomarkers of possible efficacy.

Gastrointestinal electrical stimulation for treatment of gastrointestinal disorders: gastroparesis, obesity, fecal incontinence, and constipation

Electrical stimulation of the gastrointestinal (GI) tract is an attractive concept. Since these organs have their own natural pacemakers, the electrical signals they generate can be altered by externally delivering electric currents by intramuscular, serosal, or intraluminal electrodes to specific sites in the GI tract. This article reviews the advances in electrical stimulation of the GI tract by describing various methods of GI electrical stimulation and their peripheral and central effects and mechanisms; updating the status of GI electrical stimulation in the clinical settings of gastroparesis, obesity, fecal incontinence, and constipation; and predicting future directions and developments of GI electrical stimulation technology and their areas of possible clinical applications.

Plasma ghrelin and gastric pacing in morbidly obese patients

Gastric pacing is a new treatment of morbid obesity. Patients experience increased satiety, the ability to reduce food intake, and a resultant weight loss. We hypothesized that the appetite-stimulating hormone ghrelin is involved in the changed appetite and eating behavior resulting from gastric pacing. Eleven morbidly obese patients (mean body mass index of 46 kg/m2) were treated with gastric pacing. The peripheral blood levels of ghrelin 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 hypoenergetic meal (1130 kJ [270 kcal]). Patients were followed monthly for vital signs and weight level. Gastric pacing resulted in a significant weight loss of a mean 10.4 kg or 4.4 body mass index units after 6 months of treatment. No negative side effects or complications were observed during the treatment. Ghrelin levels decreased significantly in response to food intake at all visits. After activation of the pacemaker, levels of ghrelin were significantly increased (P<.01) as compared with before activation. Weight loss correlated significantly with increased ghrelin levels (R=0.69, P<.05). Gastric pacing is a promising therapy for morbid obesity. It is suggested that increased ghrelin after gastric pacing is an adaptation to negative energy balance without a causal role in weight loss or body weight maintenance.

Effect of acute gastric electrical stimulation on the systemic release of hormones and plasma glucose in dogs

This study evaluated the effect of gastric electrical stimulation (GES) with various parameters on plasma concentrations of satiety-related peptides and glucose. GES was performed in nine healthy dogs via electrodes implanted in the middle of the lesser curvature. Four sessions were performed in each animal: control, stimulation with IGS (implantable gastric stimulation for obesity, 0.3 m sec), modified IGS (2 msec), and long pulses (300 msec). Blood samples were collected at 15 and 0 min before the meal and at 15, 30, and 60 min after the meal. GES was initiated 30 min before the first blood sample and maintained throughout collection. Plasma ghrelin, leptin, insulin and glucose were measured. The total AUCs of plasma ghrelin and leptin were not significantly affected by GES. The total AUC of plasma insulin was significantly lower with IGS and long pulse parameters (P < 0.05). The total AUC for plasma glucose was significantly lower in sessions with long pulses and modified IGS parameters (P < 0.05). We conclude that acute GES is able to change the release of some satiety-related peptides. Whether this is associated with the changed eating behavior and weight loss in obese patients needs further investigation.

Looking to the future: electrical stimulation for obesity

Among all classes of therapies for morbid obesity-behavioral, drugs, devices, and surgery-devices for electrical stimulation are a relatively new approach. This article reviews the history of electrical therapies for the gastrointestinal tract with an emphasis on the development of stimulation for obesity. Based on similar animal work, electrical stimulation of the gastrointestinal tract has been applied to treat morbid obesity much in the way it has been used to treat nausea and vomiting. The current status of gastrointestinal electrical stimulation for the treatment of morbid obesity is reviewed, with an emphasis on human studies. The physics of electrical stimulation and the possible mechanism of stimulation in the gastrointestinal tract, including for the treatment of morbid obesity, are also discussed. Future work on stimulation for obesity offers the opportunity for better understanding of possible mechanisms of action.

Update on obesity surgery

The prevalence of obesity in the United States has reached epidemic proportions. With more than 30 million Americans clinically obese, the younger population has also been affected. Surgical therapy should be offered to the severely obese patient who is refractory to nonsurgical therapy, as established by the 1991 NIH Consensus Conference on Gastrointestinal Surgery for Severe Obesity. Surgery is currently the most effective therapy for weight loss. It is far more effective than any other treatment modality, both in terms of the amount of weight loss and in terms of durability in maintaining weight loss.

Does vagal nerve stimulation affect body composition and metabolism? Experimental study of a new potential technique in bariatric surgery

BACKGROUND

It has been shown that vagal nerve stimulation (VNS) can affect body mass. The aim of this study was to evaluate effect of VNS on body mass, body composition, metabolic rate, and plasma leptin and IGF-I levels.

METHODS

Eight female pigs were included in the study. Under general anesthesia, a bipolar electrode was implanted on the anterior vagal nerve by laparoscopy. Group A was treated by VNS, and group B was the control. After 4 weeks, stimulation was discontinued in group A and started in group B. The following parameters were evaluated: body mass, body composition, metabolic rate, plasma leptin and IGF-1 levels and intramuscular fat content (IMF).

RESULTS

VNS attenuated body weight gain (2.28 +/- 3.47 kg vs 14.04 +/- 6.75 kg; P = .0112, for stimulation and nonstimulation periods, respectively), backfat gain (0.04 +/- 0.26 mm vs 2.31 +/- 1.12 mm) and IMF gain (-3.76 +/- 6.06 mg/g MS vs 7.24 +/- 12.90 mg/g MS; P = .0281). VNS resulted in lower backfat depth/loin muscle area ratio (0.33 +/- 0.017 vs 0.38 +/- 0.35; P = .0476). Lower plasma IGF-I concentration was found after VNS (-3.67 +/- -11.55 ng/mL vs 9.86 +/- 10.74 ng/mL; P = .0312). No significant changes in other parameters were observed.

CONCLUSIONS

VNS affects body weight mainly at the expense of body fat resources; however, metabolic rate is not affected.

The Implantable Gastric Stimulator for Obesity

OBJECTIVE

To evaluate the efficacy of a gastric stimulation procedure for the treatment of morbid obesity.

METHODS

All implantable gastric stimulator systems were implanted in a laparoscopic procedure. We focused on the results of the LOSS (Laparoscopic Obesity Stimulation Survey) study, which was a multicenter European survey of 16 hospitals. To date, 91 patients have undergone implantable gastric stimulator implantation in the LOSS study.

RESULTS

The patient population was comprised of 62 (68%) women and 29 (32%) men. The mean age was 41 years, mean weight was 116kg, and mean body mass index was 41 kg/m(2). All surgical procedures were successfully completed. There were no deaths, and no severe peri- or postoperative complications. The mean excess weight loss (EWL) was 20% at 12 months after surgery and about 25% at 2 years after implantation. Baroscreen-selected patients achieved a 31.4% EWL, which was significantly different to the EWL of those patients who were not selected by this screening (15% EWL) [p < 0.01].

CONCLUSION

Gastric pacing is a promising, minimally invasive, safe, and effective surgical method that results in very little impairment of the patient. Patient selection for gastric stimulation therapy seems to be an important determinant of treatment outcome.

Long-term follow-up of gastric stimulation for obesity: the Mestre 8-year experience

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(R)) 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.

Progress in implantable gastric stimulation: summary of results of the European multi-center study

BACKGROUND

The Implantable Gastric Stimulator (IGS(R)), a pacemaker-like device, has been found to be safe and effective to induce and maintain weight loss. The LOSS (Laparoscopic Obesity Stimulation Survey) is a prospective non-randomized trial which enrolled 69 patients involving 11 investigator centers in 5 European Countries. In 19 patients, ghrelin was analyzed.

METHODS

Between January 2002 and December 2003, 69 patients (F/M 49/20), mean age 41 years (18-65) underwent IGS implantation. Mean BMI was 41 (35-57), mean weight 115.0 kg (65-160) and mean excess weight (EW) 52 kg (13-89). The IGS was actived 30 days after implantation. In a subset of 19 patients studied further, 0, 6, and 12 months appetite and satiety score were evaluated and 0 and 6 months ghrelin profile was analyzed.

RESULTS

The mean +/- standard error %EWL was: 8.6+/-1.8 at 1 month, 15.8+/-2.3 at 3 months, 17.8+/-2.6 at 6 months, 21.0+/-3.5 at 10 months, and 21.0+/-5.0 at 15 months. There were no intraoperative surgical or long-term complications. 7 intra-operative gastric penetrations occurred, observed by gastroscopy, without sequelae. 1 patient required a reoperation to remove a retained lead needle. In the subset of 19 patients, appetite was reduced and post-prandial and inter-prandial satiety was increased after IGS implantation. In the 19 patients, despite weight reduction, ghrelin did not increase.

CONCLUSION

IGS can be implanted laparoscopically with minimal perioperative complications. Appetite is reduced and satiety is increased after the implantation. Ghrelin levels could be one of the mechanisms explaining weight loss and weight maintenance in IGS patients. If weight loss is maintained, IGS could be considered a good option for selected patients.

Gastric pacing for morbid obesity: plasma levels of gastrointestinal peptides and leptin

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.

Laparoscopic surgical concepts of morbid obesity

BACKGROUND

According to the WHO, obesity and obesity with associated morbidity constitute a chronic, multi-factorial condition requiring treatment. Conservative treatment has been shown in long-term studies to be ineffective in morbid obesity. Surgical treatments break down into restrictive, malabsorptive, combined restrictive and malabsorptive or motility-reducing procedures.

METHOD AND RESULTS

Laparoscopic implantation of an adjustable gastric band is an efficient restrictive measure for treating the majority of patients with this condition. The adjustable gastric band enables weight loss and food intake to be adapted to the individual patient's need. Of these patients, 80-90% can expect to lose 55-70% of their excess weight. Vertical banded gastroplasty is losing ground among the restrictive options. Preliminary experiences are encouraging, but the long-term results are disappointing when assessed by the standard criteria. Gastric bypass is gaining ground in Europe and is a standard procedure in the USA. This operation is estimated to give a 70-80% loss in excess weight, and provides a better quality of life than do restrictive procedures. The biliopancreatic diversion with duodenal switch combines a sleeve gastrectomy with a duodeno-ileal switch to achieve maximum weight loss. Consistent excess weight loss of between 70% and 80% is achieved, with acceptable decreased long-term nutritional complications. The laparoscopic approach to this procedure has successfully created a surgical technique with optimum benefit and minimal morbidity, especially in the super-obese patient. Intra-gastric stimulation is the least invasive surgical procedure at present. However, the excess weight loss is lowest with this method, at only 32% in the first 2 years after the operation.

CONCLUSION

Provided that safety recommendations are observed, laparoscopic operations for obesity have a fairly low risk. The mortality rate in centres with experienced staff is less than 0.3%. The death rate due to untreated morbid obesity is significantly higher than in a comparable group of patients after surgery.

Gastric electrical stimulation as therapy of morbid obesity: preliminary results from the French study

BACKGROUND

Gastric electrical stimulation to treat morbid obesity, using the Transcend Implantable Gastric Stimulator (IGS), is being evaluated. We present our preliminary results from the French segment of the worldwide study to evaluate this therapy.

METHODS

Institutionally-approved informed consent was obtained from all patients. The IGS is placed laparoscopically. The system has two implantable components: 1) a lead with two electrodes that is implanted in a gastric lesser curvature muscle tunnel; 2) the lead is connected to an electrical pulse generator positioned subcutaneously on the abdominal wall. Two electrode positions were used; half (6/12, 50%) were "low" near the pes anserinus, and the other 50% "high" nearer the esophagogastric junction. Intraoperative gastroscopy is used to diagnose inadvertent gastric perforation. 12 patients (5 M, 7 F) had the IGS implanted between July 2000 and February 2001. Mean age was 40.6 years (31-51). Mean weight was 122.2 kg (93-146), mean BMI was 42.7 kg/m2 (39.1-48.6), and mean excess weight was 60 kg (42-74). Electrical stimulation commenced 1 month after implantation.

RESULTS

All devices were successfully placed laparoscopically. There were no deaths or major operative complications. Postoperative course was uneventful in all cases. In 25% (3/12), postoperative lead dislodgement occurred; 2 of the 3 had their leads replaced. By 9 months, mean excess BMI lost was 30 +/- 24% or 16 +/- 12 kg.

CONCLUSION

Implanting the IGS to treat morbid obesity is technically feasible and safe. Lead dislodgement has been simply and satisfactorily corrected. Satisfactory short-term weight loss has been achieved in a subset of patients. Long-term efficacy must now be determined.

Gastric pacing as therapy for morbid obesity: preliminary results

BACKGROUND

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

METHODS

Morbidly obese subjects (BMI > or = 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 achieved 38 and 67 %EBL. In the second study, every patient lost weight. At 36 months follow-up, 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 (IGS) as therapy for human morbid obesity: report from the 2001 IFSO symposium in Crete

This supplement contains reports from a symposium on a novel approach to treat obesity, gastric myo-electrical stimulation, that was held at the IFSO in Greece in 2001. There were four presentations. Xavier Pi-Sunyer from Columbia University in New York discussed medical risks of obesity. Karl Miller from Austria presented technical aspects of the surgery. Valerio Cigaina from Italy, the originator of the concept, reviewed his 7-year results with this therapy. Finally, Jerome D'Argent from France gave his preliminary results employing higher energy electrical stimulation parameters. Customarily weight loss data are presented as percent excess weight lost (%EWL), an antiquated measurement, e.g. all subjects were purchasing life insurance, the poor and minorities were under-represented and those with heart disease, malignancies or diabetes were excluded. In this supplement weight loss data are presented in a novel manner: percent excess body mass index (BMI) lost %EBL. This innovation merits an explanation and justification. The NIH/NIDDK convened a panel, chaired by Professor Pi-Sunyer, that concluded that for adults a BMI of 25 should be considered the upper limit of normal. Accordingly, we have proposed that BMI units in excess of 25 be considered to represent 100% of the excess weight of an individual. The USA FDA has agreed to accept weight loss data presented as %EBL. The intriguing data presented justify further evaluation of this novel, potentially useful and relatively benign treatment of obesity.

Implantable electrical gastric stimulation to treat morbid obesity in the human: operative technique

BACKGROUND

The surgery to place the implantable gastric stimulator (IGS) is described.

METHODS

There are two implantable components to the IGS. One is the electrical stimulator itself, which is placed in the anterior abdominal wall. It is connected to a bipolar lead that is positioned in the muscle wall of the stomach. We describe the procedure that is necessary to safely place the components.

RESULTS

4 patients have been implanted using techniques that were developed and refined around the world. There were no operative deaths. All procedures were successfully completed laparoscopically. Two (2/4) connections required revision because the leads were not fully inserted into the header of the generator.

CONCLUSIONS

The operation to implant the IGS is safe and simple to perform. Attention to technical details is essential.

Gastric pacing as therapy for morbid obesity: preliminary results

BACKGROUND

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

METHODS

Morbidly obese subjects (BMI > or = 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 achieved 38 and 67 %EBL. In the second study, every patient lost weight. At 36 months follow-up, 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 (IGS) as therapy for human morbid obesity: report from the 2001 IFSO symposium in Crete

This supplement contains reports from a symposium on a novel approach to treat obesity, gastric myo-electrical stimulation, that was held at the IFSO in Greece in 2001. There were four presentations. Xavier Pi-Sunyer from Columbia University in New York discussed medical risks of obesity. Karl Miller from Austria presented technical aspects of the surgery. Valerio Cigaina from Italy, the originator of the concept, reviewed his 7-year results with this therapy. Finally, Jerome D'Argent from France gave his preliminary results employing higher energy electrical stimulation parameters. Customarily weight loss data are presented as percent excess weight lost (%EWL), an antiquated measurement, e.g. all subjects were purchasing life insurance, the poor and minorities were under-represented and those with heart disease, malignancies or diabetes were excluded. In this supplement weight loss data are presented in a novel manner: percent excess body mass index (BMI) lost %EBL. This innovation merits an explanation and justification. The NIH/NIDDK convened a panel, chaired by Professor Pi-Sunyer, that concluded that for adults a BMI of 25 should be considered the upper limit of normal. Accordingly, we have proposed that BMI units in excess of 25 be considered to represent 100% of the excess weight of an individual. The USA FDA has agreed to accept weight loss data presented as %EBL. The intriguing data presented justify further evaluation of this novel, potentially useful and relatively benign treatment of obesity.

Implantable electrical gastric stimulation to treat morbid obesity in the human: operative technique

BACKGROUND

The surgery to place the implantable gastric stimulator (IGS) is described.

METHODS

There are two implantable components to the IGS. One is the electrical stimulator itself, which is placed in the anterior abdominal wall. It is connected to a bipolar lead that is positioned in the muscle wall of the stomach. We describe the procedure that is necessary to safely place the components.

RESULTS

4 patients have been implanted using techniques that were developed and refined around the world. There were no operative deaths. All procedures were successfully completed laparoscopically. Two (2/4) connections required revision because the leads were not fully inserted into the header of the generator.

CONCLUSIONS

The operation to implant the IGS is safe and simple to perform. Attention to technical details is essential.