Primary Endoluminal Techniques for Weight Loss

1998

2002

2004

2008

2013

2018

US morbidly obese population BMI >40

7.0%

8.9%

9.8%

10.3%

10.6%

11.3%

US obese population, BMI >35 with comorbidities (millions)

9.1%

11.7%

14.1%

15.7%

16.9%

18.7%

Number of bariatric procedures

13,365

72,177

121,055

210,820

246,896

386,186

Human trials of endoluminal treatments of obesity are limited to small patient populations and short follow-up. Several companies have no human data but have innovative devices in development. It is this fertile ground of overwhelming demand from well-informed patients combined with evolving technologies that has given birth to many endoluminal and minimally invasive procedure concepts. The convergence of emerging endoscopic technology and the demand for less invasive therapy for obesity in the coming years will place the bariatric endoscopist in a unique position to advance the treatment of this disease.

The rate of bariatric surgery increased from 6.3 to 32.7 procedures per 100,000 adults each year between 1998 and 2005, and the continued pressure to provide ambulatory surgery, endoluminal, and transgastric therapy has the potential to effect major changes in the way obesity is treated. Currently, our surgical procedures can create excess weight loss in patients with morbid obesity ranging from 40 to 80% with acceptably low complication rates [5, 6]. The concepts described in this chapter use natural orifice access (trans-oral) to eliminate the trauma of abdominal incisions; this lower risk approach may also expand interest among patients and referring physicians. While current technology is being applied endoluminally, there is interest in pursuing more advanced procedures within the peritoneal cavity using natural orifice surgery. These applications are known as natural orifice transluminal endoscopic surgery (NOTES), and interests of this emerging field are managed by the Natural Orifice Surgery Consortium for Assessment and Research (NOSCAR). NOSCAR has established guidelines for the development and clinical use of NOTES technology [7, 8]. With the potential benefits of natural orifice access surgery, these approaches may represent a potentially safer, simpler, and less costly option than current minimally invasive procedures.

Primary endoluminal therapy for bariatric patients is rapidly evolving with concepts and devices early in their development cycle. Though early results are promising, long-term data is absent. We must be vigilant in evaluating the next generation of devices within well-constructed clinical trials in order to determine their safety, efficacy, and durability.

Category 1: Gastric Restriction

Generally these devices utilize upper endoscopy to place sutures or tissue anchors in the stomach in order to reduce gastric volume. However, there are innovative oral devices to restrict intake as well. Below are the devices currently being evaluated in this application and their potential indication for the treatment of obesity.

The EndoCinch (C.R. Bard, Murray Hill, NJ) product has previously been used to treat GERD. It has been recently used for endoluminal gastroplasty by Fogel et al. in several studies in both adults and adolescents with positive results. Figure 19.1 illustrates the pattern to those sutures deployed in a continuous and cross-linked fashion from the proximal fundus to the distal body in order to restrict gastric volume. Once the series of stitches are completed, the continuous suture is tightened and secured with a suture fastening device, thus limiting functional gastric volume.

Fig. 19.1

This device functions by suctioning tissue into the capsule mounted on the tip of the endoscope and advancing a hollow needle, preloaded with a T tag suture, through the captured tissue. Before sending the needle through, the tissue is heated to stimulate scarring as an adjunct to tissue bridging. The advancing needle tip remains safely within the shaft of the device and pushes the fastener across the base of the tissue fold. Anterior and posterior suture bites are taken starting at the most distal point in the stomach (a). If a continuous suture was used, the device is then removed over the suture (b) and the suture fastening device is placed over the ends of the suture outside the patient and passed down into the stomach (c). Once the tissue is approximated, the suture fastening device is deployed and the gastroplasty is complete (d). If interrupted sutures are used, this sequence is repeated for each plication point

The largest study completed by Fogel et al. was completed in Venezuela (the study institution in Venezuela did not have an IRB), and it should be noted that many successfully screened patients were not eligible due to insufficient health insurance coverage or a means of covering the procedure costs. In this study of 64 patients, the majority were female (49 women (76.6%)) with a mean BMI of 39.9 ± 5.1 (range 28.0–60.2 kg/m²) and had a mean preoperative weight of 104.8 ± 18.5 kg (range 74–178 kg). Their ages ranged from 16 to 62 years, with a mean (SD) of 31.5 ± 10.1 years. Results of these 64 patients were further subdivided by BMI: group 1 (baseline BMI ≥40 kg/m²), group 2 (baseline BMI 35–40 kg/m²), and group 3 (baseline BMI <35 kg/m²), with a total of 33, 19, and 12 patients in each group, respectively. There was no statistically significant difference in the mean ages of the three BMI groups; however, group 3 had a higher female:male ratio with approximately 92% female. At the study’s conclusion, patients did not report any serious adverse events, and no overnight observations were required.

One year follow-up in their study included 59 of the 64 patients (94.1%). Routine endoscopic follow-up was not performed, however. Overall percent excess weight loss (%EWL) results at 1, 3, and 12 months were 21.1 ± 6.2%, 39.6 ± 11.3%, and 58.1 ± 19.9%, respectively [9].

Fogel and colleagues also reported their results in 2009 of trans-oral gastroplasty in 21 obese adolescents at 18 months with an average %EWL of 61% without serious adverse events [10]. Patients ranged in age from 13 to 17 years of age, and the majority were female (n = 18) with a mean BMI of 36.2 kg/m² and weighed between 80 and 157 kg. Patients returned for follow-up at 1, 3, 6, 12, and 18 months post-procedure. The most recent data indicates eight patients with 18 months follow-up resulted in EWL of 61.5% (45.7–77.3%). Also reported was 12-month follow-up with a mean EWL of 67.3% (51.7–82.9) and 6-month follow-up with mean EWL of 63.8% (range, 47.1–80.5%).

There are several new technologies without any human data. Shown in Fig. 19.2, Apollo Endosurgery (Austin, TX) has developed Overstitch Endoscopic Suture System to provide physicians the ability to perform several different types of tissue apposition within the gastrointestinal tract. Bard’s second-generation Restore Suturing System™ (RS2) devices as well as Apollo’s instrument share a key improvement over previous endoluminal stitching systems, allowing the surgeon to reload the suture without the need for removing the endoscope. These devices are disposable and are used with standard flexible endoscopes. A pilot study of endoluminal gastric plication has been completed using the Restore Suturing System. The 12-month follow-up data demonstrated the safety and feasibility of this procedure in 18 patients at two sites. At 12 months (n = 14), investigators observed decreases in the mean weight (−11.0 ± 10.0 kg, P = 0.0006), mean BMI (−4.0 ± 3.5 kg/m², P = 0.0006), and mean waist circumference (−12.6 ± 9.5 cm, P = 0.0004). The mean excess weight loss at 12 months was 27.7 ± 21.9%. The proportion of patients with an EWL of ≥20% or ≥30% was 57% and 50%, respectively. However, the plications were not found to be durable on endoscopic evaluation [11].

Fig. 19.2

Apollo Endosurgery Overstitch Endoscopic Suture System

Also, SafeStitch (Miami, FL) is currently developing the Intraluminal Gastroplasty Device which works by suctioning two sides of the stomach lining into position for suturing and placing a row of sutures through the two sides of the stomach mimicking an intraluminal gastroplasty. As Fig. 19.3 reveals, it functions by injecting adrenaline into the mucosa, elevating it for excision, excising the top layer of the entrapped stomach wall, releasing this tissue, removing the device, and tightening the sutures.

Fig. 19.3

SafeStitch is currently developing the Intraluminal Gastroplasty Device. It functions by injecting adrenaline into the mucosa, elevating it for excision, excising the top layer of the entrapped stomach wall, releasing this tissue, removing the device, and tightening the sutures

Deviere et al. and Moreno et al. are authors on two recent publications regarding the trans-oral gastroplasty, or TOGA™ System (Satiety, Inc, Palo Alto, CA) [12, 13]. The TOGA System is a flexible stapler introduced endoscopically under direct vision (Fig. 19.4). The result of the fired device is an endoluminal gastric plication with full thickness apposition thus reducing reduced total gastric volume. At this point, the device has been shown to be feasible and safe with good preliminary results. The technology uses opposing vacuum extensions to approximate and staple anterior and posterior walls of the stomach. The stapler is closed and fired, allowing a serosa-to-serosa apposition of anterior and posterior walls of the stomach, parallel with the lesser curvature, creating a gastric partition. The stapler is withdrawn and reloaded to extend the endoluminal sleeve up to total length of 8 cm from the GEJ. In the final step to the procedure, an internal diameter of approximately 20 mm is reduced to approximately 12 mm by using the TOGA restrictor at the distal end of the plication.

Fig. 19.4

The TOGA System is a flexible stapler introduced endoscopically. The result of the fired device is an endoluminal gastric plication with full thickness apposition thus reducing reduced total gastric volume. After the device is placed into the stomach, a structural wire is deployed to distend the greater curvature laterally (a). The suction chambers of the device engage the anterior and posterior gastric walls under direct vision from a retroflexed endoscope (b). Once the tissue is captured, the stapler is fired to approximate the gastric walls and this sequence is repeated two or three times to create a vertical gastroplasy (c)

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