**2. Malabsorptive procedures**

#### **2.1 Gastrointestinal bypass liners**

With the success of the Roux-Y Gastric Bypass (RYGB), attempts have been made to develop nonsurgical endoscopic procedures which mimic the attributes of the RYGB. Several companies have come up with gastrointestinal bypass liners which are removable, replaceable, and do not require gastric stapling or permanent changes to the patient's anatomy.

### *2.1.1 The EndoBarrier*

A promising alternative to bariatric surgery is the EndoBarrier (**Figure 1**) (GI Dynamics Inc., Lexington Massachusetts, USA). This device is an endoluminal duodenal bypass liner (DJBL), which mimics the malabsorptive features of the RYGB.

#### *2.1.1.1 Technique*

The EndoBarrier consists of a single use endoscopic system including a liner, delivery system, and retrieval system. The liner, a Teflon covered sleeve that is impermeable to nutrients, extends 65 cm into the small bowel and can remain in situ for up to 3–12 months. Under general anesthesia, a capsule containing the liner and its anchor will be placed at the duodenal bulb with fluoroscopic guidance. The device has anchors with barbs of nitinol located at its proximal end, which functions as a self-expandable stent. This allows fixation to the duodenal bulb distal to the pylorus, but proximal to the ampulla of Vater. In this way, the liner is anchored proximally, whereas the distal part extends into the jejunum due to peristalsis of the intestine. The liner is open at both sides, to ensure the passage of chyme from the stomach while bypassing the duodenum. Along the outside of the liner, pancreatic juices and bile will enter from the ampulla of Vater, thereby avoiding contact with gastric contents until these exit the sleeve in the jejunum. In this way, it mimics the malabsorptive effects of the RYGB, without the permanent alterations of the intestinal anatomy and its complications. The device is licensed for 1 year, after which it should be removed. In order to remove the liner, a custom drawstring of the device can be grasped with an endoscope, to which the device will collapse and subsequently can be gently removed from the gastrointestinal tract.

#### *2.1.1.2 Efficacy and safety profile*

To date, there have been multiple observational studies and five randomized controlled trials assessing the efficacy of the EndoBarrier [4]. The first post marketing nonrandomized trial was conducted in the United Kingdom, in which 45 obese patients with a mean BMI of 39.9 kg/m2 were recruited [5]. The study comprised a 12-month period with the EndoBarrier inserted and a 6-month follow-up period after it had been explanted. Average implantation time was 27 min and no procedure-related complications occurred. A total of 31/45 patients completed the

**37**

**Figure 1.** *The EndoBarrier.*

*Endoluminal Techniques to Treat Obesity DOI: http://dx.doi.org/10.5772/intechopen.82733*

reduction in BMI of 4.9 kg/m2

BMI of 35 kg/m2

study, 41 patients with a mean BMI of 49 kg/m2

full 12 month-period, whereas 14 patients had a premature removal of the device. In two patients, this was due to a device-related adverse event, namely melena and device migration causing abdominal pain. In the remaining 31 patients, a mean

tion in weight was maintained 6 months after the removal of the device. In another

EndoBarrier and a low calorie diet [6]. After 12 weeks, the mean excess weight loss (EWL) in the device group versus the control group was 19 versus 6.9%, respectively. In one large multicenter trial carried out in the Netherlands, 73 patients were randomized to either EndoBarrier implantation in combination with dietary intervention or dietary intervention alone [7]. Thirty-five subjects with a baseline

just before the device removal, the EndoBarrier group had lost 32.0% [22.0–46.7%] of their excess weight versus 16.4% [4.1–34.6%] in the control group (p < 0.05). In addition, the EndoBarrier-group demonstrated the impact on diabetic control, with improvements in HbA1c of 1.3% compared to 0.3% in the control group. Only one early device removal was reported due to the blockage of the Endobarrier with food. A recent systematic review and meta-analysis assessing the effect of the EndoBarrier on weight loss and glycemic control in obese patients with type 2 diabetes mellitus concluded that the EndoBarrier induces significant weight loss and improves glycemic control in this population [8]. With regard to safety, the most frequently reported side effect of the EndoBarrier is abdominal pain and nausea, which commonly resolves after the body is used to having the device in situ. More serious complications that have been reported are gastrointestinal bleeding, device migration, and the formation of hepatic abscesses. However, the first international data from the EndoBarrier worldwide registry suggest that the likely benefits of the EndoBarrier far outweigh the risks. The registry, including 403 Endobarrier patients, reported 4 cases of hepatic abscesses, 15 cases of gastrointestinal bleeding, and 8 cases of device migration [9]. In conclusion, the EndoBarrier has shown to be a promising and feasible technique that is able to account for significant weight loss in obese patients and moreover improves glycemic control in those with T2DM. However, while the liner is currently licensed for only 1 year, a vast majority of the patients risk to lose the beneficial effects of the device after removal and subsequently will regain weight. In the study of Forner et al., 72% of the patients regained their weight 6 months postremoval of the EndoBarrier [10]. Future research should be focused on reimplantation strategies or a device that could

was observed at 12 months. In addition, this reduc-

received the EndoBarrier for a period of 6 months. After 6 months,

were randomized between the

#### *Endoluminal Techniques to Treat Obesity DOI: http://dx.doi.org/10.5772/intechopen.82733*

*Recent Advances in Laparoscopic Surgery*

reviewing the current literature.

**2. Malabsorptive procedures**

**2.1 Gastrointestinal bypass liners**

changes to the patient's anatomy.

*2.1.1.2 Efficacy and safety profile*

obese patients with a mean BMI of 39.9 kg/m2

*2.1.1 The EndoBarrier*

*2.1.1.1 Technique*

onset of obesity. In this chapter, we aim to present the current state of field regarding investigational procedures in the treatment of obesity that are already available in clinical practice or in advanced stages of development. This chapter outlines their potential mechanism of action and their safety and efficacy in clinical practice, by

With the success of the Roux-Y Gastric Bypass (RYGB), attempts have been made to develop nonsurgical endoscopic procedures which mimic the attributes of the RYGB. Several companies have come up with gastrointestinal bypass liners which are removable, replaceable, and do not require gastric stapling or permanent

A promising alternative to bariatric surgery is the EndoBarrier (**Figure 1**) (GI Dynamics Inc., Lexington Massachusetts, USA). This device is an endoluminal duodenal bypass liner (DJBL), which mimics the malabsorptive features of the RYGB.

The EndoBarrier consists of a single use endoscopic system including a liner, delivery system, and retrieval system. The liner, a Teflon covered sleeve that is impermeable to nutrients, extends 65 cm into the small bowel and can remain in situ for up to 3–12 months. Under general anesthesia, a capsule containing the liner and its anchor will be placed at the duodenal bulb with fluoroscopic guidance. The device has anchors with barbs of nitinol located at its proximal end, which functions as a self-expandable stent. This allows fixation to the duodenal bulb distal to the pylorus, but proximal to the ampulla of Vater. In this way, the liner is anchored proximally, whereas the distal part extends into the jejunum due to peristalsis of the intestine. The liner is open at both sides, to ensure the passage of chyme from the stomach while bypassing the duodenum. Along the outside of the liner, pancreatic juices and bile will enter from the ampulla of Vater, thereby avoiding contact with gastric contents until these exit the sleeve in the jejunum. In this way, it mimics the malabsorptive effects of the RYGB, without the permanent alterations of the intestinal anatomy and its complications. The device is licensed for 1 year, after which it should be removed. In order to remove the liner, a custom drawstring of the device can be grasped with an endoscope, to which the device will collapse and

subsequently can be gently removed from the gastrointestinal tract.

To date, there have been multiple observational studies and five randomized controlled trials assessing the efficacy of the EndoBarrier [4]. The first post marketing nonrandomized trial was conducted in the United Kingdom, in which 45

prised a 12-month period with the EndoBarrier inserted and a 6-month follow-up period after it had been explanted. Average implantation time was 27 min and no procedure-related complications occurred. A total of 31/45 patients completed the

were recruited [5]. The study com-

**36**

full 12 month-period, whereas 14 patients had a premature removal of the device. In two patients, this was due to a device-related adverse event, namely melena and device migration causing abdominal pain. In the remaining 31 patients, a mean reduction in BMI of 4.9 kg/m2 was observed at 12 months. In addition, this reduction in weight was maintained 6 months after the removal of the device. In another study, 41 patients with a mean BMI of 49 kg/m2 were randomized between the EndoBarrier and a low calorie diet [6]. After 12 weeks, the mean excess weight loss (EWL) in the device group versus the control group was 19 versus 6.9%, respectively. In one large multicenter trial carried out in the Netherlands, 73 patients were randomized to either EndoBarrier implantation in combination with dietary intervention or dietary intervention alone [7]. Thirty-five subjects with a baseline BMI of 35 kg/m2 received the EndoBarrier for a period of 6 months. After 6 months, just before the device removal, the EndoBarrier group had lost 32.0% [22.0–46.7%] of their excess weight versus 16.4% [4.1–34.6%] in the control group (p < 0.05). In addition, the EndoBarrier-group demonstrated the impact on diabetic control, with improvements in HbA1c of 1.3% compared to 0.3% in the control group. Only one early device removal was reported due to the blockage of the Endobarrier with food. A recent systematic review and meta-analysis assessing the effect of the EndoBarrier on weight loss and glycemic control in obese patients with type 2 diabetes mellitus concluded that the EndoBarrier induces significant weight loss and improves glycemic control in this population [8]. With regard to safety, the most frequently reported side effect of the EndoBarrier is abdominal pain and nausea, which commonly resolves after the body is used to having the device in situ. More serious complications that have been reported are gastrointestinal bleeding, device migration, and the formation of hepatic abscesses. However, the first international data from the EndoBarrier worldwide registry suggest that the likely benefits of the EndoBarrier far outweigh the risks. The registry, including 403 Endobarrier patients, reported 4 cases of hepatic abscesses, 15 cases of gastrointestinal bleeding, and 8 cases of device migration [9]. In conclusion, the EndoBarrier has shown to be a promising and feasible technique that is able to account for significant weight loss in obese patients and moreover improves glycemic control in those with T2DM. However, while the liner is currently licensed for only 1 year, a vast majority of the patients risk to lose the beneficial effects of the device after removal and subsequently will regain weight. In the study of Forner et al., 72% of the patients regained their weight 6 months postremoval of the EndoBarrier [10]. Future research should be focused on reimplantation strategies or a device that could

**Figure 1.** *The EndoBarrier.*

remain in situ for longer, thereby providing a more permanent solution. A recent study already demonstrated implantation of a new prototype for up to 3 years in two obese subjects with T2DM, but high frequency and severity of AE's still preclude the use of the device for a period longer than 1 year [11]. Efforts are made to kick start further development to combat these issues.
