Early Diagnosis of Anastomotic Leakage After Colorectal Surgery: a Prospective Observational Validation Study of the Dutch Leakage Score, Serum Procalcitonin and Serum CRP: the Italian ColoRectal Anastomotic Leakage (iCRAL) Study Group.

BACKGROUND

Anastomotic leakage is a dreaded major complication after colorectal surgery. The overall incidence of anastomotic dehiscence and subsequent leaks is 2 to 7 percent when performed by experienced surgeons. The lowest leak rates are found with ileocolic anastomoses (1 to 3 percent) and the highest occur with coloanal anastomosis (10 to 20 percent). Leaks usually become apparent between five and seven days postoperatively. Almost half of all leaks occur after the patient has been discharged, and up to 12 percent occur after postoperative day 30. Late leaks often present insidiously with low-grade fever, prolonged ileus, and nonspecific symptoms attributable to other postoperative infectious complications. Small, contained leaks present later in the clinical course and may be difficult to distinguish from postoperative abscesses by radiologic imaging, making the diagnosis uncertain and underreported.

There is no uniform definition of an anastomotic dehiscence and leak. In a review of 97 studies, as an example, 56 different definitions of an anastomotic leak were used. The majority of reports define an anastomotic leak using clinical signs, radiographic findings, and intraoperative findings. The clinical signs include: Pain, Fever, Tachycardia, Peritonitis, Feculent drainage, Purulent drainage. The radiographic signs include: Fluid collections, Gas containing collections. The intraoperative findings include: Gross enteric spillage, Anastomotic disruption.

Risk factors for a dehiscence and leak are classified according to the site of the anastomosis (extraperitoneal or intraperitoneal). A prospective review of 1598 patients undergoing 1639 anastomotic procedures for benign or malignant colorectal disease found a significantly increased risk of anastomotic leak with extraperitoneal compared with intraperitoneal anastomoses (6.6 versus 1.5 percent; 2.4 percent overall).

Major risk factors for an extraperitoneal anastomotic leak include: The distance of the anastomosis from the anal verge (Patients with a low anterior resection and an anastomosis within 5 cm from the anal verge are the highest risk group for an anastomotic leak), Anastomotic ischemia, Male gender, Obesity.