Purpose: Anastomotic leak following colorectal resection surgery is associated with short and long-term negative patient outcomes, prolonged hospitalization, and increased healthcare costs. Various patient related and surgical factors are known to contribute to the development of postoperative anastomotic leaks. This study systematically reviewed the literature to assess the incidence of post-operative leak and identify patient factors associated with the development of leaks. Methods:Articles published from 1/1/2003 -8/8/2015 reporting on post-operative anastomotic leak following colorectal resection surgery were identified in the Medline and Embase databases. The rate of post-operative leak, as well as patient and surgical characteristics, were extracted.Results: Forty-three articles met study inclusion criteria. Within the 14,102 cases, 867 patients experienced anastomotic leak, yielding an average leak rate of 6.1%. Patients were primarily male (57.0%) and had a mean age of 60.2 years. The majority of patients received a stapled anastomosis (70.9%), and most resection surgeries were performed for a diagnosis of cancer (80.7%). Comparison of patient characteristics with and without a post-operative leak revealed male gender, diabetes, open surgical procedures, and sutured anastomoses to be risk factors of anastomotic leak. Patients with anastomotic leak had a longer length of stay in the hospital and higher mortality rate than patients without a leak. Conclusions:Anastomotic leak remains a major concern in colorectal resection surgery and occurs in approximately 6.1% of cases. Both patient and surgical factors are associated with the development of post-operative anastomotic leak, which is linked to negative patient outcomes and increased mortality.

048 AbstractPurpose: Anastomotic leak following colorectal resection surgery is associated with high rates of morbidity, infection, and escalated healthcare expenditures. One method to prevent leaks includes early detection through intra-operative testing. This study employed systematic review of the literature to estimate the rate of intra-operative anastomotic leaks in colorectal resection surgery. Method:The Medline and Embase databases were searched to identify articles published between January 1 st , 2003 and August 8 th , 2015 reporting on intra-operative leaks in colorectal resection. The rate of intra-operative testing, intra-and post-operative anastomotic leaks, and surgical methodology were extracted from the final sample of 13 articles.Results: A total of 167 intra-operative leaks were reported within 2,598 colorectal resection surgeries that used intra-operative testing, yielding an average leak rate of 6.4%. Use of laparoscopic techniques was significantly associated with a reduced rate of intra-operative leak (p<0.001). Eight articles reported on the rate of post-operative anastomotic leak in relation to intraoperative testing. Within this sample of 2,098 cases a non-significant trend towards a lower leak rate in the tested population was identified (4.3% v. 6.8%, p=0.051); cases whose leak test was initially positive exhibited a significantly higher rate of post-operative leaks compared to cases with a negative leak test (p=0.006). Conclusion:Intra-operative anastomotic leak testing allows surgeons to address leaks at the time of surgery, and may help to prevent complications in colorectal resection surgery. This study identified a mean intra-operative leak rate of 6.4% in colorectal resection surgery.