*9.1.2 Anastomotic insufficiency or staple line leaks*

The insufficiency of an anastomosis or a staple line leak results in a leakage of enteral fluids into the abdomen. The visceral fat, which is present in pathological amounts, can result in occult peritonitis without typical pain symptoms this conditioned a delay of the detection of the insufficiency. Different endoscopic therapeutic procedures have been established in cases of clinical suspicion of an insufficiency or in cases of proven insufficiencies.

In the case of early detection of insufficiency, re-laparoscopy and, if necessary, overstitching may be appropriate. Often a combination of re-laparoscopy, lavage and drainage for sepsis control and endoscopic therapy is indicated. In hospitals with obesity centers and a 24-hour endoscopy rendezvous procedures with intraoperatively endoscopy could be established. Especially in cases of very small leaks, a reliable identification of the leak can be made [40].

The most frequently performed endoscopic therapy for leakages after bariatric surgery worldwide is the stent therapy [41]. A challenge is the stent fixation in bariatric patients. Stent dislocation is the most common complication of this type of therapy. Special bariatric stents have been developed. The leading brands ECBB HanaroStent® (MI-tech, Seoul, South Korea), MegaStent™ (Taewoong, Seoul, South Korea) and Gastro Seal™ (MI-tech, Seoul, South Korea) are stents 2013 [42]. In addition to the common hemo-clips, the endoscopic sewing machine (EndoStich®, Apollo endosurgery, USA) [43, 44] and a special OTSC (OTSC®Stentfix, Ovesco, Germany) can be used for stent fixation [43].

The endoscopic negative pressure therapy (ENPT) is based on an open-pored element (e.g. a sponge), which is either endoluminally inserted at the stage of the leakage or into the resulting insufficiency cavity (intracavitary). The open-pore element is fixed to a drainage with perforations, which is connected to a vacuum source. The negative pressure acts through the pores on the surrounding tissue and results in a continuous drainage of secretions, cell-detruitus and bacteria, the suction induces tissue proliferation [45]. Due to the good clinical results this therapy is used for numerous leakages of the gastrointestinal and urogenital tract [46, 47]. ENPT is also known under the synonyms E-VAC and EVT. For ENPT as primary endoscopic procedure for leakage, possibly in combination with laparoscopy, three studies are currently available with a cumulative success rate of 90.27% in a total of 31 patients [48–50]. In addition, there are numerous case reports and studies, some of which deal with the combined use of ENPT with stent procedures as first and second line therapy [51].

Closure of leakage after bariatric surgery can be successfully performed with OTSC® as first or second line therapy with good results up to closure rates of 86.3% [52, 53].

The drainage of secretions through an internal drainage by implantation of a double-pigtail-drainage to endoluminal can lead to a successful healing of the insufficiency in up to 78% according to the study results [41].
