Updates on endoscopic bariatric therapies from DDW
Four studies presented at this year’s Digestive Disease Week have highlighted the benefits endoscopic bariatric therapies as primary and revisional procedures, as well as an endoluminal techniques to assess the identification of gastric sleeve stenosis (GSS).
In the first paper, ‘Primary Obesity Surgery Endoluminal 2 (pose 2.0): An international multicenter prospective trial with plication durability assessment’ (Presentation Number: 51), an international team of investigators reported the initial results that examined the safety, efficacy and durability of the POSE2 procedure. The POSE2 procedure is performed using the Incisionless Operating Platform (IOP, USGI Medical) and involves a new pattern of full-thickness gastric plications with durable suture anchor pairs that both shortens and tabularizes the greater curvature of the stomach.
The trial included 44 patients enrolled under an IRB protocol in three centres (two in Spain, one in the US under an FDA IDE). The same moderate intensity lifestyle intervention and follow-up implemented across all centres. Time to half gastric emptying (GE1/2) of solids was obtained and the impact on satiety and satiation was measured using standardised questionnaires. Hepatic steatosis was measured via controlled attenuation parameter (CAP) with transient elastography. Weight on Quality of Life (IWQOL) questionnaire was obtained at baseline and at six months and durability of the plications assessed at 12 months with endoscopy and upper GI series.
Forty-four patients (mean age was 44.3±9.4 years, mean BMI 37.3±1.7 kg/m2, 61% female) underwent POSE2 with 19 (IQR 13-21) suture anchor pairs. Mean procedural time was 37min±11min under general anaesthesia. At three months, percent total body weight loss (TBWL) was 13.4±4.1% (n =43/44), 16.7±6.3% (n= 43/44) at six months, 16.2±6.7% (n=43/44) at 12 months and 14.17±7.32% (n=31/39) at 18 months. Percent achieving ≥10% and 15% TBWL was 86% and 56% at 12 months, respectively. Only one patient was lost to follow-up and no serious adverse events reported.
All plications were intact on repeat endoscopy at 12 months or more and 95% of the cohort had significant changes in gastric emptying at six months, compared to baseline. Gastroparesis Cardinal Symptom Index (GCSI) did not change at six weeks compared to baseline (p=0.18), except for the post-prandial fullness subscale, which increased from 0.67 to 4 (p<0.001).
Fasting and post-prandial satiety and satiation scores improved significantly at two and six months, compared to baseline (p<0.001). Alanine aminotransferase improved from a baseline of 33.4mg/dL to 19.1mg/dL at six months (p=0.0074), with a corresponding improvement in hepatic steatosis from a baseline CAP (n=15) of 299 dB/m to 220 dB/m at six months (p=0.00024).
The authors concluded that POSE 2 is a minimally invasive, effective, scalable, and durable endoscopic bariatric and metabolic therapy that targets multiple physiologic appetite pathways, and offers a real therapeutic option to fill the obesity management gap.
In a second presentation by researchers from Brigham and Women's Hospital Department of Medicine, Boston, MA, the Transoral Outlet Reduction (TORe) endoscopic revision technique was reported to have similar weight loss compared to surgical revision at three and five years. The findings were presented in the paper, ‘Endoscopic versus surgical gastrojejunal revision for weight regain in Roux-en-Y gastric bypass patients: Five-year safety and efficacy comparison (Presentation Number: 53)’.
The study researchers noted that Dilated Gastrojejunal Anastomosis (GJA) is an anatomical cause for weight regain following Roux-en-Y Gastric Bypass (RYGB) that can be corrected with diameter reduction through endoscopic (ENDO) or surgical (SURG) revision. The Transoral Outlet Reduction (TORe) endoscopic revision technique is associated with 8.8% total weight loss at five years with few adverse events, however direct comparison to surgical revision remains unknown. Therefore, the researchers compared serious adverse event (SAE) rates and weight loss profiles between ENDO and SURG revisional techniques over a five-year period.
The retrospective matched cohort study included RYGB patients who underwent ENDO or SURG revision for weight regain at least partially attributable to an enlarged GJA (>12mm) at two tertiary referral centres. ENDO patients were matched 1:1 to SURG patients based on age, sex, BMI and weight regain. Demographics, GJA size, serious adverse events (SAEs) and weight profiles were collected.
The primary outcome was comparison of SAE rates between groups, with secondary outcomes including comparisons of the amount of weight loss, reported using percentage of total weight loss (%TWL), at one-, three- and five- years.
In total, the study included 122 RYGB patients with weight regain and an enlarged GJA (61 ENDO, 61 matched SURG), with 53 patients completing five-year follow-up in the ENDO group, compared to 28 in the SURG group. Pre-revision age, sex, time since RYGB, percent weight regain from initial weight loss, weight, BMI and GJA diameter were similar between groups. The SAE rate in the ENDO group (4.9%) was lower than the SURG group (26.2%); p=0.002. SAEs within the ENDO group included GJA stenosis requiring balloon dilation (1), esophageal perforation requiring endoscopic clip closure (1) and gastrointestinal bleeding (1). SAE’s within the SURG group included leak (3), GJA stenosis requiring balloon dilation (2), intra-abdominal infection (2), superficial wound infection (2), ulcer (3), severe abdominal pain (3), gastrointestinal bleeding (2) high-grade small bowel obstruction (1), pancreas injury causing pancreatitis (1), subcutaneous neck emphysema (1) and post-operative pulmonary embolism (1). Although the SURG group experienced significantly greater weight loss at one year, there was no significant differences at three and five years.
The presenters concluded that endoscopic revision of the gastrojejunal anastomosis with TORe is associated with significantly fewer serious adverse events. Despite a lower weight loss at one year, TORe has similar weight loss compared to surgical revision at three and five years.
Revisional endoscopic sleeve gastroplasty
In the third study, ‘Efficacy of endoscopic revision versus pharmacotherapy for management of weight regain after endoscopic sleeve gastroplasty (Presentation Number: 55)’, researchers from New York Presbyterian-Cornell, New York, NY, investigators noted that up to a third of patients can experience plateauing of weight loss or varying degrees of weight regain during follow up after endoscopic sleeve gastroplasty (ESG). Available options for management of weight regain include initiation of pharmacotherapy or redo ESG. The comparative effectiveness of these options is not clear.
In this retrospective analysis of a prospectively maintained database of patients undergoing ESG. Fifty five patients were started on pharmacotherapy and 24 patients underwent redo ESG. The primary outcome of this study was change in total body weight loss (TBWL), defined as the difference between TBWL immediately prior to initiation of pharmacotherapy or performing redo ESG and the TBWL at the end of follow up.
The age (44±12 versus 44±13, p=0.879), gender distribution (64% female versus 57%, p=0.602), and baseline weight (117±32 versus 113±25 Kg, p=0.545) did not differ significantly between groups. The proportion of non-compliant patients (defined as patients who missed their post ESG follow up visits) was significantly higher in the pharmacotherapy group, compared with redo ESG group (67% versus 35%, p=0.008). Despite the difference in compliance, the TBWL did not differ significantly between groups immediately before starting pharmacotherapy or performing redo ESG (11.5% versus 10.4%, p=0.713).
The improvement in TBWL after redo ESG was significantly (both clinically and statistically) better than the improvement after initiation pharmacotherapy (9.5±7% versus 2.2±9%, difference 7.3%, 95%CI 3.5-12.1%, p=0.001). This difference favouring redo ESG remained significant after adjusting for patients' compliance in mutivariable analysis (difference 6.5%, 95%CI 1.9-11.1%, p=0.007).
“ Our results suggest that redo ESG is an effective treatment to induce further weight loss after experiencing a weight loss plateau or weight regain after ESG, while initiation of pharmacotherapy results in primarily stabilising patients' weight without inducing significant further weight loss,” the authors concluded. “Given substantial proportion of patients with weight regain after bariatric procedures including bariatric surgeries, our results highlight an important advantage of ESG as a repeatable minimally invasive procedure.”
Endoluminal Functional Lumen Imaging Probe (ENDOFLIP)
The final presentation, ‘Endoluminal functional lumen imaging probe (ENDOFLIP) can be used to assess severity of gastric sleeve stenosis (Presentation Number: 54)’, by researchers from the University of Michigan, Ann Arbor, MI and Oregon Health & Science University, Portland, OR, examined whether EndoFLIP measurements could be used to characterise severity of gastric sleeve stenosis (GSS). EndoFLIP measures luminal diameter and distensibility indices (DI) and shows promise in characterising GSS, though data remains limited.
Symptoms of GSS include dysphagia, reflux, obstruction and/or pain and endoscopic treatment with serial pneumatic balloon dilation (PBD) has been shown to result in high success, though patients may still require surgical conversion to Roux-en-Y gastric bypass (RYGB).
In their study, the researchers performed a retrospective analysis of a prospective database of patients referred for symptoms suggestive of GSS. Severity of GSS was assessed at the time of EGD, and successive (30, 35 and 40mm) PBD performed every two-four weeks until symptoms resolved. Failure was defined as referral to surgery for RYGB. EndoFLIP measurements were obtained before and after PBD by advancing the catheter (EF325) across the GSS. Measurements were monitored for 60 seconds at 30ml and 40ml and diameter and DI were recorded. All EGDs were performed by a single bariatric endoscopist who was blinded to EndoFLIP measurements. Primary endpoints were pre- and post-dilation luminal diameter and DI of GSS. Secondary outcomes include endoscopic assessment of GSS, patient characteristics and need for surgical revision.
A total of 26 patients were included in the study between 9/2018 and 10/2020. Mean (±SD) age was 45.3 years (± 9.9) and 23 (85%) were female. Mean number of dilations was 2.4 (±1.3) and ten (38%) patients were referred for RYGB. Mild, moderate, and severe GSS was found in ten patients (38%), six patients (23%) and ten (38%) patients, respectively. When stratified by severity, there was no significant difference in age or gender between the groups.
Patients with moderate and severe GSS underwent more PBDs (2.5±1.0 and 3.2±1.6, respectively) than those with mild GSS (1.8±0.8) and were more likely to be referred for surgery, though this was not statistically significant. Both pre- and post-dilation luminal diameters at 30ml and 40ml were significantly larger in those with mild versus moderate or severe GSS. Additionally, pre- and post-dilation DI at 30ml was significantly higher for mild, compared to moderate and severe GSS. While this trend was also seen with pre- and post-dilation DI at 40ml, this was not statistically significant.
“We demonstrate the role of EndoFLIP in the identification and characterization of GSS. EndoFLIP measurements correlate well with endoscopic assessment of GSS,” they concluded. “While more data is needed to determine ideal balloon size and threshold measurements, our results suggests EndoFLIP can helpful in expediting diagnosis and treatment of GSS.”