Surgical Endoscopy

, Volume 25, Issue 9, pp 3028–3033

Human experience with an endoluminal, endoscopic, gastrojejunal bypass sleeve


    • Division of Minimally Invasive Surgery, Department of SurgeryUniversity of California
  • Roberto Rumbaut
    • Hospital de Tec de Monterrey
  • C. Paul Swain
    • Imperial College of London
  • Gustavo Torres
    • Hospital de Tec de Monterrey
  • Luis Morales
    • Hospital de Tec de Monterrey
  • Lizcelly Gonzales
    • Hospital de Tec de Monterrey
  • Sarah Schultz
    • Division of Minimally Invasive Surgery, Department of SurgeryUniversity of California
  • Mark Talamini
    • Division of Minimally Invasive Surgery, Department of SurgeryUniversity of California
  • Santiago Horgan
    • Division of Minimally Invasive Surgery, Department of SurgeryUniversity of California

DOI: 10.1007/s00464-011-1665-6

Cite this article as:
Sandler, B.J., Rumbaut, R., Paul Swain, C. et al. Surg Endosc (2011) 25: 3028. doi:10.1007/s00464-011-1665-6



This report describes the authors’ experience with a unique endoluminal, endoscopically delivered and retrieved gastroduodenojejunal bypass sleeve, including short-term weight loss and changes in comorbidities.


A prospective, single-center trial was designed. The patients were morbidly obese individuals who met the National Institutes of Health criteria for bariatric surgery. The device used was a unique gastroduodenojejunal bypass sleeve secured at the esophagogastric junction with endoscopic and laparoscopic techniques and designed to create an endoluminal gastroduodenojejunal bypass. At completion of the trial, the device was explanted with endoscopic retrieval. The primary end points were safety and incidence of adverse events. The secondary outcomes included the percentage of excess weight loss and changes in comorbidities, specifically glucose control, use of antihyperglycemic medications, and changes in hemoglobin A1c levels.


From July 2008 to February 2010, 24 patients were enrolled in the trial. The gastroduodenojejunal bypass sleeve was implanted, left in situ, and then retrieved. The 7 men and 17 women in the study had a mean preoperative body mass index of 42 kg/m2. The device was successfully delivered in 22 of the 24 patients (92%) and retrieved endoscopically from all 22 patients in whom it was implanted (100%). Two patients were excluded from the study preprocedurally. The one patient was excluded preoperatively due to noncompliance with the preoperative liquid diet. For the other excluded patient, the device was not attempted endoscopically due to significant inflammation at the gastroesophageal junction at the time of laparoscopic evaluation. Of the 22 patients who had the device implanted, 17 maintained it (77%) and completed the full 12-week trial. These patients had 39.7% excess weight loss at completion of the study. The primary reason for early explantation of the device was early postoperative dysphagia. The seven patients with preoperative diabetes mellitus all had normal blood glucose levels throughout the trial, and none required antihyperglycemic medications. All four patients with elevated hemoglobin A1c levels preoperatively showed improvement by the end of the trial.


This trial demonstrated that the endoluminal gastroduodenojejunal sleeve can achieve excellent weight loss at 12 weeks. No patient safety issues were encountered. Adverse effects were minimal and resolved at endoscopic device removal. Effective glycemic control was demonstrated through use of the device during the trial. Long-term results are needed.


Endoluminal gastroduodenojejunal bypassGastroduodenojejunal bypass sleeveMorbid obesity

Morbid obesity is a debilitating disease process with significant consequences, including substantial morbidity, from even simple surgical procedures. As the incidence and prevalence of obesity increase dramatically across the United States, with more than 32% of US adults considered obese in 2008 [1] the benefits of minimally invasive approaches have become significant.

Minimally invasive surgery has significantly changed the treatment of morbid obesity by decreasing ventral hernia risks, infection rates, and other surgical morbidities. Endoluminal and natural orifice approaches to surgical procedures can be seen as extensions of these surgical concepts with potential to improve obese patient care.

Natural orifice and endoluminal surgery have been introduced with the intent to improve upon laparoscopic surgery. The theoretical advantages include less pain, lower hernia risks, improved cosmesis, and the possibility of procedures performed with the patient under sedation and without general anesthesia. Several reports of natural orifice approaches and other endoluminal approaches to bariatric surgery have been described [25]. Many attempt to mimic either the restriction or the malabsorption seen with the Roux-en-Y gastric bypass, considered the gold standard for bariatric surgery in the United States. Endoscopic delivery of these devices without the need for bowel resection or anastomosis, together with the ability to reverse the procedure or remove the device, is a characteristic shared by many of these concepts.

This report describes the human experience with an endoluminal, endoscopic gastroduodenojejunal bypass sleeve (ValenTx, Inc. Carpinteria, CA). The device was designed to mimic both the restriction and the malabsorption seen with the Roux-en-Y gastric bypass.


Study design

An institutional review board-approved, prospective, single-center trial was designed. Patients were enrolled who met the 1991 National Institutes of Health guidelines for bariatric surgery and had a body mass index (BMI) greater than 40 kg/m2 or exceeding 35 kg/m2 with comorbidities. The primary end points of the trial were the safety of the device, including the incidence of any adverse event. The secondary outcomes included the percentage of excess weight loss and changes in comorbidities seen during the trial.

The comorbidities monitored included diabetes mellitus type 2, hypertension, and hypercholesterolemia or elevated triglyceride levels. Diabetes mellitus improvements included changes in hemoglobin A1c levels as well as evaluation of the dosage and frequency of antihyperglycemic medications. Hypertension was considered improved if the systolic or diastolic pressures were improved or the patient had been able to decrease or eliminate the need for antihypertensive medications. Hypercholesterolemia and elevated triglyceride levels were considered improved if the patient had improvement in fasting laboratory values or had experienced a decrease in the preexisting medication dose.

All the patients provided written, informed consent according to an approved protocol from our institutional review board. They all had undergone a screening history and physical examination, a screening barium upper gastrointestinal swallow study, and a baseline laboratory evaluation. During the trial, data were recorded according to approved study forms.


After consent had been obtained, the patients were administered prophylactic antibiotics, together with appropriate deep vein thrombosis prophylaxis, and placed under general anesthesia in a supine position on the operating room table. The procedure began with placement of a long overtube extending through the pylorus into the duodenal bulb. Through this overtube, the gastroduodenojejunal bypass sleeve, pictured in Figs. 1 and 2, was delivered via a delivery catheter to the level of the first portion of the duodenum.
Fig. 1

The gastroduodenojejunal bypass sleeve is an implantation device delivered endoscopically with laparoscopic assistance, anchored at the gastroesophageal junction, and deployed down through the pylorus and extending through the duodenum into the proximal jejunum
Fig. 2

Close-up image of the sleeve’s proximal aspect at the point of attachment to the implanted cuff

The sleeve, a 120-cm-long fluoropolymer, was deployed down through the pylorus using the toposcopic delivery technique with computer-regulated pressure and flow monitoring. Fluoroscopic guidance also was used to ensure adequate deployment of the sleeve through the duodenum into the proximal jejunum. Once the sleeve was adequately deployed downstream into the bowel, the delivery catheter was removed, and the overtube was exchanged for a shorter overtube in preparation for the proximal cuff attachment.

Next, the patient was repositioned in a supine lithotomy position. The abdomen was prepped and draped in standard surgical fashion for the laparoscopic portion of the procedure. After placement of one 12-mm and three 5-mm trocars, together with a Nathanson liver retractor, the gastroesophageal (GE) junction was dissected circumferentially at the level of the diaphragmatic hiatus using ultrasonic dissection, and a Penrose drain was placed to assist with further manipulation.

The polyester cuff was positioned endoscopically at the GE junction at the level of the Z-line. The positioning was completed with the assistance of a removable stent, which helped with visualization of the esophageal lumen at the GE junction. The attachment was performed using eight endoscopically delivered, full-thickness suture anchors deployed in a circumferential manner with the assistance of laparoscopic visualization to ensure full-thickness suture-anchor placement and to avoid visceral injury. Once the cuff had been anchored, the stent was detached endoluminally and removed through the overtube via a drawstring at its proximal end.

After cuff attachment, the left and right diaphragmatic crura were laparoscopically approximated with suture closure. The Penrose drain and all the trocars were removed, and the incisions closed appropriately. The patient then was awakened from anesthesia.

Postoperatively, the patient was monitored in the hospital for 2–4 days. A gastrograffin swallow study was performed on postoperative day 1 to evaluate sleeve and cuff positioning. Once this was completed, the postoperative diet was initiated. This consisted of a full liquid diet for the first 2 weeks, followed by a pureed diet for 2 weeks, then progressed to regular food without caloric restriction. The patient was followed with regular appointments and scheduled laboratory evaluation to monitor for anemia, routine chemistries, liver function panels, pancreatic enzyme levels, and strict blood glucose monitoring.

At completion of the study period, the device was removed endoscopically using standard sedation protocols. This was completed through endoscopic ligation of the eight anchoring sutures. The cuff then was gently mobilized using an endoscopic grasper, and after circumferential detachment was ensured, gently slid out of the esophagus together with the attached sleeve.


From July 2008 to February 2010, the trial prospectively enrolled 24 patients (7 men [29%] and 17 women [71%]) with a mean age was 40.2 years (range, 23–55 years) and a mean body mass index (BMI) of 42 kg/m2 (range, 35.4–50.8 kg/m2). The mean starting weight was 114.8 kg (range, 81.8–177.8 kg). Seven of the patients who completed the study had at least one comorbid condition. All seven patients had diabetes mellitus type-2. In addition, two of these patients had hypertension, and three had hyperlipidemia.

Of the 24 patients, 22 had attempted device implantation. One patient was excluded preoperatively because she was noncompliant with the preoperative liquid diet. The remaining exclusion occurred after laparoscopic dissection had begun, and implantation was not performed due to significant inflammation at the GE junction. The mean time for sleeve deployment was 11 min (range, 3–55 min). The mean operative time from skin incision to closure was 65 min (range, 37–116 min). A total of 22 explanations were performed, and all 22 were completed entirely endoscopically.

No procedure-related complications were encountered, and no operative conversions were performed during the device implantation. No operative assistance was needed during endoscopic removal.

Of the 22 implanted patients, 5 (23%) underwent explantation before the 12-week scheduled removal. One explantation occurred during the first week after implantation, two during week 2, and two during week 3. Each of these patients experienced pain with swallowing, three during the liquid diet phase and two during the pureed diet phase. The pain completely resolved at explantation of the device. Laboratory values remained normal for each patient before and after device explantation.

No device migration occurred during the study period, and no patient experienced device obstruction. One patient had difficulty with the transition to pureed food at 2 weeks. Follow-up barium swallow showed the device to be fully deployed in a good position within the small bowel, but the sleeve had kink within the stomach. Follow-up endoscopy was performed during week 3 to straighten the sleeve, with good result, and the patient then transitioned to solid foods without further difficulty. No laboratory abnormality was encountered during the study. No adverse event related to the device or the procedure occurred throughout the trial period.

Weight loss data were available for all 17 patients who completed the study. The average starting BMI was 42 kg/m2 (range, 35.4–50.8 kg/m2). The average percentage of excess weight loss was 39.7% (range, 27–64%), as seen in Fig. 3. The average total weight loss was 16.8 kg (range, 8.6–30.8 kg). All the patients reported earlier and greater satiety as well as lower food intake after device implantation.
Fig. 3

Summary of the mean percentage of excess weight loss (%EWL) for the patients during the 12-week trial

Comorbidity data were tracked for the patients with preexisting medical conditions. Of the 17 patients who completed the study, 7 had diabetes mellitus type-2, 2 had hypertension, and 3 had hyperlipidemia. All of the seven diabetic patients required medication to control their disease before the procedure. None of the seven required antihyperglycemic medication after device implantation. Four of the seven patients had elevated hemoglobin A1c levels at baseline, and each improved this value during the trial period. The two patients who had hypertension were able to stop their antihypertensive medications by the end of the trial. Three of the patients had hyperlipidemia before device implantation, and these values had normalized by completion of the study.

Safety monitoring included routine laboratory screening during the trial period. The screening tests included complete blood count, serum electrolytes, liver function panels, and serum pancreatic enzyme levels, all of which remained normal throughout the study period.


Morbid obesity, a devastating disease process with serious life-limiting consequences, is becoming increasingly more prevalent in many Western countries. Conservative treatment options, including lifestyle changes, medication introduction, and even supervised dietary modification, have produced only modest success in treating this disorder [6, 7]. Surgical intervention has proved to be the most successful and reproducible method for achieving effective weight loss in the treatment of morbid obesity.

Despite the success of surgery, many patients are hesitant to pursue measures viewed by some as radical or extreme. The reasons behind this are not entirely clear, but many fear complications of the surgery such as anastomotic leak, abscess, marginal ulceration, food intolerance, dumping syndrome, permanent anatomic alteration of the gastrointestinal tract, and long-term nutritional risks. The role of minimally invasive bariatric surgery still is evolving as device and procedure improvements are continually achieved. Endoscopic devices and procedures are the natural extension and evolution of this minimally invasive movement.

This study evaluated the safety and early efficacy of the endoluminal bypass sleeve device. The design of this device is thought to reproduce the restrictive and malabsorptive features seen with a Roux-en-Y gastric bypass, the gold standard for surgical weight loss in the United States. A food bolus passes through the esophagus into the device, and then down through the 120-cm polymer sleeve into the proximal jejunum, creating a gastric, duodenal, and biliopancreatic bypass.

Of the 22 devices implanted by the three surgeons in the study, 5 required early explantation during the first 3 weeks of the study. We believe this was related to cuff position in the distal esophagus. In first two device explantations, the cuff had been placed a bit too high, resulting in significant pain and restriction when the two patients swallowed. Both patients experienced some nausea and pain when swallowing liquids. With device explantation, the pain at swallowing resolved completely for both patients.

The remaining three early explanted patients were asymptomatic for the first 2 weeks during the liquid phase of the postoperative diet, but when transitioning to pureed foods, experienced pain with swallowing. Radiographic evaluation showed that the cuff was positioned a bit high. Endoscopic device explantation resulted in pain resolution.

The remaining 17 patients tolerated the device for the full 12-week study period. No significant pain or intolerances were seen during this period in this group. No patient reported any dietary restriction once the transition to solid food was made, but most reported small meal size and early satiety. No significant nausea or vomiting was seen during the trial other than in the five patients requiring early device explantations.

The sleeve devices were anchored at the level of the GE junction through suturing between the polyester cuff and the esophageal wall. The remaining sleeve position varied between the patients in the trial because the sleeve had no attachment points other than the proximal cuff. Most of the patients had a length of 10–40 cm in the stomach, with the remainder of the 120 cm length in the duodenum and proximal jejunum.

The attachment procedure was both an endoscopic and a laparoscopic procedure because the laparoscopy allowed external visualization to ensure full-thickness suture placement at the cuff–GE junction level. The laparoscopic dissection of the GE junction was circumferential because the sutures were placed full-thickness in a circumferential fashion. The posterior diaphragmatic crural closure was necessary to prevent iatrogenic hiatal hernia.

In this early device development phase, the laparoscopic visualization was deemed necessary to ensure patient safety. With future device improvement and development, the laparoscopic visualization may be eliminated, allowing this procedure to be performed entirely endoscopically.

The three endoscopists in the trial performed all 22 endoscopic device explanations. The mean time to explantation was significantly longer for the first three procedures because endoscopic shears were used to cut the prolene suture anchors. As the technique was improved, endoscopic ablation catheters were used to melt the suture material gently, allowing much shorter explantation times.

No complications with explantation of the device were seen. Adherence to the esophageal wall was a theoretical concern, but this was not encountered at removal of the cuff or device.

The 39.7% average excess weight loss seen during the 12-week study was an interesting finding for a short-term study design. The gastroduodenojejunal sleeve appears to be very effective in achieving significant weight loss, and no significant adverse effects of this weight loss were seen, specifically no problems with dehydration, diarrhea, abdominal pain, nausea, or emesis, except for the five patients requiring early explantation described earlier. Side effects of rapid weight loss, although significant concerns, were not seen during this short trial.

The effectiveness of the gastroduodenojejunal sleeve was substantial and likely related to the significant early satiety described by most of the patients. The device functions both as a restrictive device limiting food intake and as a malabsorptive device limiting nutrient contact at the duodenal and jejunal mucosal surface level. The malabsorptive effects of the device, although effective for the short-term weight loss seen in this trial, were not significant enough to cause symptoms of dumping syndrome, abdominal cramping, or any steatorrhea in the short term, but more investigation is warranted.

The effects of the liquid diet, although important in the early portion of the trial, likely did not have an impact on the patients’ success with weight loss because their diet was restricted only in the first 2 weeks after implantation. The comorbidity changes seen with improvement in diabetes, hypertension, and hyperlipidemia all are compatible with this degree of weight loss. The 12-week trial design, although short, was intended to demonstrate the short-term safety of the gastroduodenojejunal sleeve, and although this was established with this short-term follow-up period, the long-term efficacy of the device remains an unanswered question and an area of ongoing investigation.


The gastroduodenojejunal bypass sleeve can be safely implanted, left in situ, and removed endoscopically without significant adverse side effects. The weight loss results seen with this device approach those published for Roux-en-Y gastric bypass and sleeve gastrectomy in the short term. Continued patient follow-up assessment, enrollment, and further study are warranted to evaluate the gastroduodenojejunal bypass sleeve, to establish its mid- and long-term safety, and to establish further the clinical effectiveness of the device in treating morbid obesity.


Bryan J. Sandler, Roberto Rumbaut, Gustavo Torres, Luis Morales, and Lizcelly Gonzales have served as consultants for ValenTx Corporation. Santiago Horgan and C. Paul Swain have served as consultants for and have an equity interest in ValenTx Corporation. Sarah Schultz and Mark Talamini have no conflicts of interest or financial ties to disclose.

Copyright information

© Springer Science+Business Media, LLC 2011