Anastomotic leak is one of the most serious complications following gastrointestinal (GI) surgery, with considerable implications for patient morbidity, length of hospital stay, reoperation rates, and mortality1. Despite advancements in surgical techniques, perioperative care, and tissue-sealing technologies, the burden of anastomotic failure remains clinically significant and economically costly1.

The incidence of anastomotic leaks varies widely, influenced by anatomical site, patient condition, and surgical complexity. Colorectal and upper gastrointestinal anastomoses are particularly vulnerable, with reported leak rates ranging from 2% to 25% in various studies2,4. Several patient- and surgery-related factors have been identified as contributors, including advanced age, malnutrition, anemia, diabetes, hypoalbuminemia, emergency procedures, and prolonged operative time2,5. Male sex has also been independently associated with increased risk, especially in lower GI anastomoses3.

Emergency surgeries further amplify the risk due to suboptimal physiological conditions, contamination, and insufficient preoperative preparation5. Prolonged operative duration, often reflecting technical challenges or intraoperative complications, is another strong predictor of anastomotic failure6.

Given the diversity of anastomotic techniques and patient presentations in GI surgeries, there is a need for institution-specific data to evaluate real-world leak rates and associated risk profiles. This study aims to determine the incidence of anastomotic leaks in a tertiary care setting and identify contributing factors that may influence anastomotic integrity. By elucidating these associations, we aim to guide clinical decision-making and reinforce preventive strategies in perioperative surgical practice.

Study Design and Setting

This was a prospective observational study conducted over a 3-month period from January 10th to April 10th at the Department of Surgical Gastroenterology and General Surgery, Government Medical College (GMC), Anantapuramu, a tertiary care teaching hospital in Andhra Pradesh, India.

Study Population

A total of 180 consecutive patients undergoing gastrointestinal (GI) anastomosis both elective and emergency procedures were enrolled after obtaining informed consent. Patients of all age groups and both sexes were included. Exclusion criteria were patients undergoing only stoma formation without anastomosis, those lost to follow-up within the first 10 postoperative days, and those with pre-existing intra-abdominal infections.

Data Collection

Baseline demographic data including age, sex, comorbidities (such as diabetes mellitus, anemia, and hypoalbuminemia), and nutritional status were recorded. Surgical details type and site of anastomosis, urgency of surgery (elective or emergency), operative time, and intraoperative findings were documented.

Patients were followed postoperatively for evidence of anastomotic leak, defined clinically by signs such as fever, abdominal pain, feculent drain output, or peritonitis, and confirmed radiologically by contrast-enhanced computed tomography (CT) or imaging showing extravasation of contrast material or intra-abdominal collections adjacent to the anastomosis.

Outcome Measures

The primary outcome was the incidence of anastomotic leak. Secondary outcomes included risk factors contributing to leak, management modality (conservative vs. surgical), mortality, and length of hospital stay.

Statistical Analysis

Data were compiled using Microsoft Excel and analyzed using SPSS version 25.0 (IBM Corp., Armonk, NY). Categorical variables were expressed as frequencies and percentages, while continuous variables were presented as mean ± standard deviation. The association between categorical variables and anastomotic leak was assessed using the Chi-square test or Fisher’s exact test. A p-value < 0.05 was considered statistically significant.

Ethical Considerations

Necessary permissions were taken from concerned authorities before starting the study. Written informed consent was obtained from all participants prior to enrollment.

A total of 180 patients who underwent gastrointestinal (GI) anastomosis were included in the study. The mean age of the study population was 52.6 ± 13.4 years, with a male predominance (60.5%, n=109) (Table 1).

Table 1. Demographic and Clinical Profile of Patients (N = 180)

Incidence and Site Distribution of Anastomotic Leaks

Anastomotic leaks were identified in 27 patients, representing an overall leak rate of 15.0%. The highest leak rates were observed in esophagojejunal (22.7%) and colorectal (22.2%) anastomoses, while duodenojejunal anastomoses had the lowest leak rate at 8.3%. The distribution of leaks across various anastomotic sites is detailed in Table 2.

Table 2. Anastomotic Leak Rate by Site of Anastomosis

Factors Associated with Anastomotic Leak

On univariate analysis, several clinical and perioperative parameters showed a statistically significant association with the occurrence of anastomotic leaks. These included age over 60 years (p=0.02), emergency surgery (p<0.001), hypoalbuminemia (<3.0 g/dL, p<0.001), prolonged operative time (>180 minutes, p=0.001), diabetes mellitus (p=0.01), and preoperative anemia (Hb <10 g/dL, p=0.002). Male gender was not significantly associated with leak occurrence (p=0.22) (Table 3).

Table 3. Association of Risk Factors with Anastomotic Leak

            * Statistically significant; ** Highly significant

Clinical Presentation, Management, and Outcomes

The median time to detection of anastomotic leak was 5 days (range: 3–10 days). The most common presenting features included fever (81%), abdominal pain (74%), and feculent drain output (41%). Diagnosis was made predominantly using contrast-enhanced CT imaging (63%), with the remainder based on clinical suspicion and drain findings.

Among the 27 patients with leaks, 14 cases (51.9%) were managed conservatively with antibiotics and percutaneous drainage, while 13 patients (48.1%) required surgical re-exploration. The mortality rate among patients with anastomotic leak was 22.2%, compared to an overall mortality of 6.1% in the total cohort. Patients with leaks had a significantly prolonged hospital stay (16.4 ± 4.8 days) compared to those without leaks (9.2 ± 3.1 days) (Table 4).

Table 4. Leak Presentation, Management, and Outcomes

Anastomotic leakage remains a critical concern in gastrointestinal surgery, significantly contributing to increased morbidity, re-intervention, prolonged hospitalization, and mortality. The incidence observed in our study (15%) aligns with global data, which suggests leak rates ranging from 2% to over 20% depending on the anastomotic site, surgical approach, and patient-related factors7.

Esophagojejunal and colorectal anastomoses exhibited the highest leak rates in our cohort, consistent with reports that lower GI anastomoses, particularly in the pelvis, are more susceptible due to anatomical, vascular, and pressure-related challenges8,9. Similarly, our findings reaffirm that male gender and emergency surgery, both of which have been previously associated with impaired healing and higher intraoperative stress, are important predictors of leak risk9.

Multiple risk factors were found to be significantly associated with anastomotic leaks in this study—namely, age above 60 years, prolonged operative time, hypoalbuminemia, diabetes, and anemia. These are well-recognized contributors to impaired tissue perfusion, delayed wound healing, and reduced immune competence10,11. Midura et al., in a large national analysis, also demonstrated the compounded effect of these comorbidities on leak risk, with an associated rise in mortality and intensive care utilization11.

The clinical presentation in our patients, with fever and feculent drain output, was typical of early postoperative leaks. CT imaging proved invaluable for timely diagnosis, reinforcing its role in the surveillance of high-risk patients7. The management outcomes in our series, with successful conservative treatment in approximately half of the cases and surgical re-intervention in the rest, reflect current global practices and underscore the importance of individualized, case-based decision-making12.

Importantly, the mortality rate among patients with leaks was 22.2%, comparable to figures reported in literature, where leak-associated mortality may range from 10% to 35% depending on severity and response to management10,12. These findings highlight the necessity of meticulous surgical technique, perioperative optimization, and heightened vigilance in high-risk cases to reduce the incidence and consequences of anastomotic leaks.

Anastomotic leak remains a significant postoperative complication in gastrointestinal surgery, with a notable incidence of 15% in this study. Esophagojejunal and colorectal anastomoses were most commonly affected. Factors such as advanced age, emergency procedures, prolonged operative time, hypoalbuminemia, diabetes, and anemia were significantly associated with increased leak risk. Early recognition, supported by vigilant clinical monitoring and imaging, is critical to timely management. While conservative treatment was successful in selected cases, surgical re-intervention was often required. Strengthening preoperative risk assessment and optimizing modifiable factors may substantially reduce the incidence of leaks, improve outcomes, and enhance patient safety in gastrointestinal surgical practice.

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