Third-space endoscopy to the rescue: what is the role of gastric peroral endoscopic myotomy in the management of gastric sleeve stenosis?

According to the recent International Federation for the Surgery of Obesity and Metabolic Disorders global registry report [1], the laparoscopic sleeve gastrectomy (LSG) is the most commonly performed bariatric surgical procedure worldwide. The exponential growth of LSG is due to various patient-related factors such as perceived benefits of preserving gastrointestinal tract continuity, absence of hypoabsorptive manifestations, and lack of necessity for aggressive vitamin supplementation. Other significant contributors are operator-dependant factors such as technical ease and short operative times [2]. Nonetheless, complications such as staple line leaks and fistulas, bleeding, and especially gastric sleeve stenosis (GSS) may occur postoperatively [2].

Among the various complications following LSG, GSS is the most heterogeneous in terms of clinical presentation, timing of presentation postoperatively, and response to treatment. As a mainly restrictive operation with intentional narrow gastric tube construction, all patients experience a degree of restriction, which is most pronounced in the early postoperative period. In our experience, patients with even subtle narrowing at the incisura angularis may present with obstructive symptoms. Conversely, patients with severe GSS may occasionally present with only symptoms of gastroesophageal reflux disease, somehow coping with their unfavorable gastric anatomy.

“Gastric peroral endoscopic myotomy (G-POEM) appears to be a safe and effective endoscopic option for refractory gastric sleeve stenosis. Patients in whom pneumatic dilation fails may be suitable for G-POEM in an attempt to avoid complex revisional bariatric procedures.”

In recent case series, the incidence of GSS post LSG varied widely from 0.1 %–3.9 % [3]. This range may be accounted for by the subjective nature of reporting, with a lack of definite parameters to define GSS and the broad patient cohorts. Although diagnostic criteria for GSS still lack clarity, objective measurements such as the ratio of narrowest to widest gastric lumen diameters have recently been proposed as predictors of GSS [4].

In this issue of Endoscopy, Zhang et al. [5] describe the results of gastric peroral endoscopic myotomy (G-POEM) in 13 GSS cases. Their efforts to classify cases as helical (axial deviation) and nonhelical (straight staple line) GSS and to analyze their outcomes independently must be commended. However, readers must be mindful that this is a heterogeneous population, with only 2/13 patients having nonhelical GSS, 3/13 presenting with a concomitant leak, and 3/13 undergoing G-POEM as an initial endoscopic treatment. Therefore, any conclusion on post-treatment outcomes of nonhelical GSS may be premature.

Clinical success was defined as symptomatic improvement with adequate oral intake and no further interventions required [5]. With a median follow-up of 5.8 months (range 4–8.7 months), 10/13 cases were defined as successful: 6/13 had complete symptom resolution, 4/13 were deemed partial responders, and 3/13 required salvage Roux-en-Y gastric bypass (RYGB) for persistent symptoms. Similarly, in our experience with GSS treated with pneumatic dilation, 20 % of “successful cases” were partial responders (< 50 % clinical improvement) but were willing to tolerate their symptoms to avoid salvage RYGB [6]. It is suspected that the majority of partial responders may eventually become failures during long-term follow-up. As such, this relatively short 5.8-month follow-up period may overestimate the success of the G-POEM technique.

From a technical standpoint, G-POEM for GSS is more challenging than the standard G-POEM performed for gastroparesis, owing to the longer tunnel and myotomy required, the tortuosity of the gastric sleeve, and the presence of larger gastric vessels. Previous endoscopic myotomy experience and advanced endoscopic therapeutic skills are necessary before undertaking these challenging cases. The absence of significant adverse events and only two inadvertent inconsequential mucosotomies reflect the advanced technical skills of the senior authors of this article.

Another contentious issue is the quantification of successful response to treatment in GSS. As no validated outcome tools exist, the authors used the Gastroparesis Cardinal Symptom Index (GCSI) score in their analysis [5]. As correctly emphasized by the authors, the GCSI score is not ideal for GSS outcome assessment [5]. This article highlights the deficiency and clear need for future validated questionnaires to adequately assess GSS severity and response to treatment.

An interesting avenue of future research is the potential use of impedance planimetry in the diagnosis, confirmation of adequate myotomy, or even as a predictor of treatment response [7]. In the Zhang et al. article, the authors describe a rather long full-thickness myotomy, with a median length of 8 cm [5]. Future studies aimed at determining the optimal length of myotomy (and possibly its orientation) are required, while acknowledging that such an entity would be difficult to define given the variability in GSS configuration. Specific tools such as impedance planimetry [7] or 3 D computed tomography reconstruction with gastric volumetry [8] may offer additional information to the usual endoscopic and fluoroscopic evaluation. This may enable individual tailoring of the endoscopic myotomy, especially in more complex helical GSS.

In conclusion, based on this small case series, G-POEM appears to be a safe and effective endoscopic option for refractory GSS. Patients in whom pneumatic dilation fails may be suitable for G-POEM in an attempt to avoid complex revisional bariatric procedures. However, the exact treatment algorithm for these challenging GSS cases requires further clarification. Larger sample sizes in prospective institutional review board-approved studies are needed to identify which GSS cases are most likely to benefit from an endoscopic myotomy.

Publication History

Article published online:
14 December 2021

• References

• 1 Welbourn R, Pournaras DJ, Dixon J. et al. Bariatric surgery worldwide: baseline demographic description and one-year outcomes from the second IFSO Global Registry Report 2013–2015. Obes Surg 2018; 28: 313-322
• 2 Sillen L, Andersson E, Olbers T. et al. Obstruction after sleeve gastrectomy, prevalence, and interventions: a cohort study of 9,726 patients with data from the Scandinavian Obesity Surgery Registry (SOReg). Obes Surg 2021; 31: 4701-4707
• 3 Ogra R, Kini GP. Evolving endoscopic management options for symptomatic stenosis post-laparoscopic sleeve gastrectomy for morbid obesity: experience at a large bariatric surgery unit in New Zealand. Obes Surg 2015; 25: 242-248
• 4 Yu JX, Dolan RD, Bhalla S. et al. Quantification of gastric sleeve stenosis using endoscopic parameters and image analysis. Gastrointest Endosc 2021; 93: 1344-1348
• 5 Zhang L, Canto M, Schweitzer M. et al. Gastric peroral endoscopic myotomy (G-POEM) for the treatment of gastric sleeve stenosis: a feasibility and safety study. Endoscopy 2022; 54: 376-381
• 6 Deslauriers V, Beauchamp A, Garofalo F. et al. Endoscopic management of post-laparoscopic sleeve gastrectomy stenosis. Surg Endosc 2018; 32: 601-609
• 7 Yu JX, Baker JR, Watts L. et al. Functional lumen imaging probe is useful for the quantification of gastric sleeve stenosis and prediction of response to endoscopic dilation: a pilot study. Obes Surg 2020; 30: 786-789
• 8 Hanssen A, Plotnikov S, Acosta G. et al. 3D volumetry and its correlation between postoperative gastric volume and excess weight loss after sleeve gastrectomy. Obes Surg 2018; 28: 775-780