Endoscopic treatment of leaks and strictures after laparoscopic one anastomosis gastric bypass

Background: Laparoscopic one anastomosis gastric bypass has become a prominent bariatric procedure. Yet, early and late complications, primarily leaks and strictures, are not uncommon. This study summarizes our experience with endoscopic treatment of laparoscopic one anastomosis gastric bypass complications. Methods: This is a retrospective study of consecutive patients referred to our hospital from 2015 to 2017 with post laparoscopic one anastomosis gastric bypass complications. Therapy was tailored to each case, including fully covered self-expandable metal stents, fibrin glue, septotomy, internal drainage with pigtail stents, through-the-scope and pneumatic dilation. Success was defined as resuming oral nutrition without enteral or parenteral support or further surgical intervention. Results: Nine patients presented with acute or early leaks: 5 (55.6%) had staple-line leaks, 3 (33.3%) had anastomotic leaks and 1 (11.1%) had both. All were treated with stents. Adjunctive endoscopic drainage was applied in 4 patients (44.4%). Overall 5 patients (55.6%) with acute/ early leaks recovered completely, including all 3 patients with anastomotic leak and the patient with both leaks but only 1/5 with staple line leak (20%). Complication rate in the leak group reached 22.2%. Eight patients presented with strictures, 7 at the anastomosis and one due to remnant stomach misalignment. All anastomotic strictures were dilated successfully. However, the patient with the pouch stricture required conversion to Roux-en-Y gastric bypass after 3 failed attempts of dilatation. Conclusion: Endoscopic treatments of laparoscopic one anastomosis gastric bypass complications are relatively effective and safe. Anastomosis-related complications are more amenable to endoscopic treatment compared to staple line leaks.


Background
Morbid obesity has become a major global health threat that leads to severe morbidity including diabetes, hypertension, obstructive sleep apnea and cardiovascular diseases. To date, bariatric surgery is the most effective intervention for weight reduction and remission of associated comorbidities [1]. Laparoscopic one anastomosis gastric bypass (LOAGB), introduced in 1997 [2], is gaining popularity and has become the fourth most performed surgery in Europe and the Asia/Pacific area [1,3]. Results with LOAGB in terms of weight loss and resolution of comorbidities have been promising [4][5][6]. Still, early and late complications occur at an estimated rate of 3.1% and 10% respectively [7]. Potential adverse events include postoperative or chronic leaks and strictures. Endoscopic management of postoperative leaks is challenging and constantly evolving with no clear guidelines. The aim of endoscopic treatment is to divert gut secretion away from the leak site to allow fistula healing and resuming oral nutrition as early as possible. These goals may be achieved by deploying fully covered self-expanding metal stents (FC-SEMS) [8][9][10][11][12][13].
Other strategies including over the scope clips (OTSC), fibrin glue, endoscopic suturing and intragastric drainage (IGD) with double pigtail stent (DPS) have been all described with variable success rate [9,[14][15][16][17]. In cases of chronic leak with perigastric collection formation, a typical complication of laparoscopic sleeve gastrectomy (LSG), the preferred (an effective) endoscopic approach is to enable adequate drainage of the perigastric collection into the stomach by dissecting the septum separating the two cavities (septotomy), and to reduce the intragastric pressure by realignment of the sleeve axis using pneumatic balloon dilatation [18]. Post-surgical strictures are treated with endoscopic dilatation. While anastomotic strictures are amenable to through the scope (TTS) dilation with high success rates [19,20], post LSG strictures due sleeve misalignment are more difficult to treat. In these cases pneumatic dilatation is preferred [21]. The aim of this study was to summarize our experience in treating post LOAGB complications amenable to endoscopic treatment, namely leaks and strictures.

Methods
This was a retrospective study of consecutive patients referred to our departmentwith post LOAGB leaks or strictures between August 2015 and October 2017. The diagnosis was based upon symptoms, imaging and endoscopic studies. Patients were managed by a multidisciplinary team that included bariatric surgeons, gastroenterologists from the bariatric endoscopy service, invasive radiologists and nutritionists. Success was defined as resuming oral nutrition without enteral or parenteral support or further surgical intervention.

Results
Seventeen patients were referred to our clinic, 9 with postoperative leaks and 8 with postoperative strictures.
Overall, 5 of 9 patients (55.6%) were successfully treated as defined by weaning from total parenteral nutrition, resuming oral diet, removal of intra-abdominal draining tubes, and avoidance of further surgical intervention ( Table 2). All 3 patients with anastomotic leak had a favorable outcome. However only 1 of 5 patients with staple line leak had a favorable outcome. Of note, the patient with both anastomotic-and staple line-leaks recovered.
Two patients were referred to Roux-en-Y-gastric bypass (RYGB) conversion. One patient needed urgent laparotomy after 2 weeks of treatment due to stent migration and ileum perforation. Interestingly, this patient did not require further treatment for his staple-line leak. The forth patient died due to respiratory failure unrelated to the endoscopic procedure. Of note, 3 of 4 failed patients (75%) had previous bariatric surgery.

Postoperative stricture group:
Eight patients were diagnosed with stricture based upon symptoms of vomiting and excessive weight loss. All of them were female with a mean age of 49±13.7 and preoperative mean BMI of 38.7±8.7 (kg/m2). Four patients (50%) had previous bariatric surgery (Table 3). Stricture site and mode of treatment are depicted in Table 4. Seven patients (87.5%) presented with anastomotic stricture and one patient (12.5%) with a midpouch kink. The median time between surgery and the first endoscopic dilatation was 63 days (IQR 37-140), and the median number of therapeutic endoscopic dilatations was 3 (2)(3)(4). Anastomotic strictures were TTS-dilated with a maximal balloon diameter of 20 mm and the pouch stricture was pneumatically dilated with a balloon diameter of 30 mm.
Overall success rate was 87.5%. All 7 patients with anastomotic stricture reported significant clinical improvement ( Table 4). The patient with the pouch kink was defined as a treatment failure due to persistent vomiting and weight loss after 3 attempts of pneumatic dilatation and finally underwent conversion to formal RYGBsurgery.

Discussion
Herein we demonstrate that endoscopic treatment of post-LOAGB leaks and strictures is effective and safe. To our knowledge this is the largest series described to date. In 10 of 17 patients a previous bariatric procedure had been performed (58.9%), which is a known risk factor for post-surgery complications [22,23]. Interestingly, LOAGB complications may be divided into anastomosis-related stricture and leaks which resemble those of RYGB [24][25][26], and staple line leaks and remnant stomach axis deviation (kink) which are similar to those of LSG [27-29]. Our data show a 100% (7/7) success rate in TTS dilation of anastomotic strictures without any complications, similar to the 93%-100% success rate for post RYGB anastomotic stricture dilation [30]. Anastomotic leaks controlled with stent insertion also exhibited a favorable outcome with 100% success (3/3), perhaps slightly higher than treatment of post RYGB anastomotic leaks which ranges between 70-94% [30]. In contrast, treatment of staple line leaks exhibited a less favorable outcome with a success rate of only 20% (1/5), compared to 65-95% in acute and early leaks after LSG [30]. Of note, two patients evolved to a late type of leak and received ancillary drainage with septotomy and DPS. Although we achieved excellent control of late and chronic leaks after LSG with this approach [18], currently it succeeded in only one patient. Another patient had remnant stomach misalignment (kink) with failure to dilate it pneumatically.
The high rate of failure in treatment of staple line-related complications may be attributed to the high percent of previous bariatric procedures (60%) in these patients which may prevent an adequate intragastric pressure reduction that would allow the leak to heal The safety profile is acceptable. Overall, we had two major complications. One case of stent migration resulted in small bowel perforation which necessitated urgent laparotomy.
One death occured, however it was not related to the endoscopic procedure.
Our study has several limitations. These include a relatively small group of patients, performance at a single tertiary referral centre, and no control group in the study design.

Ethics approval and consent to participate
The study was approved by the local ethic review board of Tel Aviv Sourasky Medical Center.

Consent for publication
Not applicable.

Availability of data and materials
From the corresponding author on reasonable request.

Competing interests
The authors declare that they have no competing interests.

Funding
There are no resources of funding to be reported or declared.