Introduction:

An anastomotic leak is a serious complication following gastrointestinal surgery where a surgical connection (anastomosis) between two sections of the bowel leaks luminal contents.

Early recognition and management of this complication are crucial due to the potential for severe intra-abdominal contamination, sepsis, multi-organ failure, and even death.

Risk Factors

The risk factors for an anastomotic leak include both patient-specific and surgical factors:

Patient Factors

– Use of medications such as corticosteroids and immunosuppressants
– Lifestyle factors such as smoking and excessive alcohol consumption
– Comorbidities like diabetes mellitus
– Nutritional status, including obesity or malnutrition

Surgical Factors

– Emergency surgical procedures
– Prolonged operative times
– Pre-existing peritoneal contamination from pus or feces
– Type of anastomosis, with esophageal-gastric and colorectal anastomoses being particularly high-risk

Clinical Features

• Anastomotic leaks typically present within 3 to 5 days postoperatively but can occur at any time.
• Common symptoms include worsening abdominal pain and signs of sepsis.
• In some cases, patients might exhibit more subtle symptoms such as a prolonged ileus.
• On physical examination, patients may show localized or generalized abdominal tenderness and signs of peritonitis.
• If left untreated, the patient’s condition can rapidly deteriorate.

Investigations

• For suspected anastomotic leaks, urgent blood tests including a full blood count (FBC), C-reactive protein (CRP), and clotting screen should be performed.
• An arterial blood gas test to assess pH and lactate levels is also recommended.
• The definitive diagnostic test is a CT scan with intravenous contrast, which can reveal gas or enteric contents outside the bowel lumen. Depending on the anastomosis location, oral contrast or contrast enemas can be used to aid in diagnosis.

Management

Management of an anastomotic leak focuses on timely resuscitation and controlling contamination:

Initial Management

– Keep the patient nil by mouth (NBM)
– Administer broad-spectrum antibiotics
– Provide resuscitative intravenous fluids
– Insert a urinary catheter for fluid balance monitoring

Definitive Management

• Minor leaks can be managed conservatively with intravenous antibiotics, bowel rest, and possibly percutaneous drainage. 
• Endoluminal vacuum therapy, like Endo-SPONGE®, is an option for select cases, particularly small leaks in low rectal anastomosis. 
• Severe leaks, especially in patients showing systemic signs of sepsis or with extensive leaks, often require surgical intervention. This may involve laparotomy, washout, refashioning of the anastomosis, and/or formation of a defunctioning stoma.