**12.1 Hemorrhage**

Significant post-operative hemorrhage after bariatric surgery has been described up to 3.4%, [67] with the most common presenting symptom as tachycardia (46%), followed by melena (32%). Sleeve gastrectomy bleeding can happen from the short gastric vessels or along the staple line after transection of the stomach [68]. Bleeding can also occur from an anastomotic site intraluminally in patients with an additional bypass procedure which typically may be managed medically or endoscopically. Surgery should be considered for hemodynamic instability and failure of endoscopic therapy [67].

## **12.2 Leak**

One of the most dreaded complication after bariatric surgeries are anastomotic leaks or staple-line leaks. Leaks from SG can occur along the staple-line, with an average incidence of 1.5% [69]. Risk factors that contributed to gastrointestinal leak include oxygen dependency, hypoalbuminemia, sleep apnea, hypertension and diabetes. Additional factors that contributed to a higher leak rate include intraoperative provocative testing and placement of drain [70].

Clinical presentation of patients with leaks range from completely asymptomatic, to frank peritonitis, septic shock, and death. Unexplained tachycardia has been shown to be an initial sign of early leak [71]. Other potential signs that should cause a high index of suspicion should include fever (>38C), diffuse abdominal tenderness, cough, and persistent hiccups [72]. A concern about a leak should be investigated urgently with imaging modalities such as upper gastrointestinal series with water-soluble contrast or abdominal CT scan IV and oral contrast. Urgent reoperation is warranted for unstable patients with signs of sepsis. Stable patients with controlled leaks may undergo percutaneous drainage, antibiotic therapy and nutritional support, in conjunction with endoluminal therapies (stenting, clipping) [4, 72].

#### **12.3 Sleeve gastrectomy related complications**

#### *12.3.1 Gastroesophageal reflux disease*

Another SG related complication is new-onset gastroesophageal reflux disease (GERD), or worsening of previous GERD symptoms. A meta-analysis by Yeung et al. demonstrated significant worsening of GERD post-operatively at 19%, with de novo GERD at 23% [73]. Long-term follow up of patients show 28% of LSG patients develop esophagitis, and 8% develop Barrett's esophagus. Endoscopic assessment for presence of hiatal hernia is recommended pre-operatively, as its concomitant repair during SG can help reduce incidence of post-operative GERD [74].

#### *12.3.2 Gastric tube stenosis*

Post-SG stenosis is a rare complication with a reported incidence of 1% – 3.5% [75, 76]. The most common site for stenosis is at the incisura angularis, [76] usually presenting with gastric outlet obstruction symptoms with marked weight loss and malnutrition [4]. Diagnosis can be done with upper gastrointestinal series or contrast enhanced CT scan of the upper abdomen. Factors that contribute to development of stenosis include bougie size and oversewing of the staple line. Endoscopic dilatation is the first line of treatment which usually require multiple sessions. Failure of endoscopic intervention, long segment stenosis, or presence of delayed leakage, abscess or fistula formation necessitates surgical intervention [75, 76].
