My Experience of Six Endoscopic Weight Loss Procedures

I participated in a training programme on Endoscopic Sleeve Gastroplasty (ESG) using the OverStitch® endoscopic suturing device from Apollo Endosurgery, held at Olympus’s Medical Expert Academy in Hamburg, on June 21-22, 2016. The focused two-days hands-on and didactic sessions, complemented by informal discussions with experts in bariatric endoscopy and bariatric surgery, prompted reflection on my personal journey (as a bariatric surgeon) with endoscopic weight loss procedures.

My earliest encounter with an endoscopic aid for weight loss was the Orbera® intra-gastric balloon system (manufactured originally by Allergan, and now acquired by Apollo Endosurgery). I became acquainted with Orbera® as a tool that could be used to mitigate surgical risk in super-super obese patients (BMI>50 kg/m2) by serving as an intermediate weight loss intervention prior to bariatric surgery (usually a laparoscopic sleeve gastrectomy as the first-stage of a biliopancreatic diversion with duodenal switch). It soon became apparent to me that the Orbera® balloon was attractive also as a definitive weight loss aid for patients at the lower end of the obesity spectrum; such patients often required temporary assistance to lose a substantial quantum of weight in order to achieve a realistic body weight-target that could then be maintained by lifestyle modification.

I am fairly convinced by physiological data that the metabolic mechanisms involved in weight loss and weight maintenance are sufficiently different that balloon removal does not necessarily lead to reversion to the starting level. Nonetheless, concern remained that a limited-duration device would not serve the needs of many patients, particularly because the weight loss that can be achieved with balloon therapy is quite limited in comparison to bariatric surgery (recent data that were used by the USA FDA for approval of Orbera® in 2015 indicate average excess weight loss of 25%).

My exploration of alternative and permanent endoscopic weight loss procedures led to a chance encounter (in 2010) that evolved into to an instructive and exciting preliminary association with Satiety Inc. (based in the Bay Area of California), which had devised the TOGA® (Trans-Oral Gastroplasty) procedure. TOGA® comprised endoscopic stapling, resulting in a gastric configuration that resembled conceptually the vertical banded gastroplasty operation (minus the band) or the Magenstrasse and Mill operation (without division of the stomach). In the class of incision-less weight loss procedures, TOGA® was highly appealing. It successfully recapitulated the mechanism of established bariatric operations, whilst avoiding the risks of surgery (and fixed restrictive devices).

My negotiations will Satiety Inc. resulted in an agreement to establish the first UK centre for TOGA® at the Nuffield Hospital in Leeds. I travelled to Rome to observe the procedure, and plans were in place to travel to Minnesota in January 2011 for cadaveric training, prior to launching the UK programme. Unexpectedly, venture capital funding for Satiety Inc. was withdrawn in December 2010, and TOGA® was consigned (at least, to date) to the status of a vignette in the history of bariatric endoscopy. Clinical trial data indicated average excess weight loss of 30-50% at one year after an optimized TOGA® procedure.

Although, no doubt, a disappointing setback, the collapse of the TOGA® project, accelerated my impetus for endoscopic bariatric procedures. In 2011, I started to perform the POSE® procedure (Primary Obesity Surgery Endoscopic, from USGI Inc.) at the Spire Hospital in Leeds, and the EndoBarrier® (from GI Dynamics Inc.) at the Nuffield Hospital in Leeds. From August 2011 to May 2012, a colleague and I performed POSE® for 10 patients {7 women and 3 men; median age (range), 43 years (30-68)}. Their median initial weight (range) was 102 kg (74-150) with BMI of 35.1 kg/m2 (30.8-42.8). At 3 months follow-up, patients achieved median total body weight loss of 10%. We did not have any serious adverse events; all procedures were performed on a day-case or overnight stay basis, and no patient was re-admitted to hospital. Our early experience with POSE® appeared encouraging, and it seemed likely that loss of 15% of total body weight at one year (the accepted target for endoscopic bariatric procedures) could be achieved. Once again (reminiscent of my encounter with TOGA®), the POSE® practice was curtailed abruptly because of corporate strategy to withdraw the device from the UK market.

I continue to offer the EndoBarrier® (an endoscopically-placed duodeno-jejunal liner); although, risk benefit analysis is now skewed by concern about liver abscesses, an adverse event that resulted in premature termination of a clinical trial in the USA. Notwithstanding, the mechanistically conceptual appeal of the EndoBarrier® is engagement of the ‘foregut’ neuro-hormonal model of the Roux-en-Y gastric bypass. Like the bypass, EndoBarrier® appears to ameliorate diabetes by triggering hormonal changes independently of weight loss, and this device may play an important role in the treatment of obese diabetic patients, particularly when medical treatment has provided poor control.

The next endoscopic device that I used was the Obalon® intra-gastric balloon, in 2014-2015, at the Spire Hospital Leeds. Conceptually broadly similar to the Orbera® balloon, Obalon® offered two possible advantages. One advantage was quite real: endoscopy for introduction of the balloon was avoided because the Obalon® balloon could be swallowed as a tightly packed capsule; the capsule was confirmed to be in the stomach by fluoroscopy, and it was then inflated with pressurized gas via a thin catheter that trailed out from the mouth and could be snapped off (at a self-closing valve in the balloon). The second advantage was potential: the ‘dose’ of appetite-control and fullness could be adjusted by introduction of a second balloon (up to a maximum of three balloons), over a period of weeks. Also, it was proposed that the gas-filled Obalon® balloon was likely to rise to the fundus of the stomach, and to better engage the Ghrelin pathway. The results appeared promising but, once again (as with POSE®), corporate strategy led to withdrawal of the device. To me, Obalon® emphasized the evanescent nature of innovative weight loss interventions.

Finally: endoscopic sleeve gastroplasty (ESG) using the OverStitch®. More than 500 procedures have been performed worldwide. Follow my blog for more information as my experience evolves.

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