Unexpected Pulmonary Embolism Following Sequential Surgeries for Cholecystocolonic Fistula and Transverse Colon Perforation: A Case Report

Abstract

Introduction:
Pulmonary embolism is a fatal postoperative complication, particularly in patients undergoing  major abdominal surgery complicated by intra-abdominal infection and immobilization. Although rare, cholecystocolonic fistulas with associated colonic perforation and sepsis markedly elevate the risk of venous thromboembolism and pulmonary embolization.

Case Presentation:
A 56-year-old male presented with a three-week history of right upper quadrant abdominal pain, nausea, and vomiting. Magnetic Resonance Cholangiopancreatography (MRCP) demonstrated gallbladder wall thickening, emphysematous changes, and cholelithiasis. The patient underwent two sequential abdominal surgeries: laparoscopic adhesiolysis with partial cholecystectomy and primary colonic repair, followed by an exploratory laparotomy with right hemicolectomy and ileostomy for colonic perforation. On postoperative day 11 after the second surgery, he developed acute respiratory distress, hypoxia, and hemodynamic instability. PE was suspected and subsequently confirmed by characteristic electrocardiographic changes and a markedly elevated D-dimer level (19.83 µg/mL). The patient responded well to anticoagulation and supportive care and was discharged on hospital day 29 without complications.

Discussion:
PE remains a significant cause of postoperative morbidity and mortality, particularly following major abdominal surgeries complicated by sepsis, inflammation, and immobility. This case highlights the multifactorial etiology of thromboembolism, including multiple surgical interventions for cholecystocolonic fistula and colonic perforation, ongoing septic burden, and surgical stress. Systemic inflammation and infection create a hypercoagulable state, while delayed mobilization further increases venous thromboembolism risk. 

Conclusion:
Early recognition and prompt management of pulmonary embolism are essential in high-risk postoperative patients. A multidisciplinary care approach is critical to improve clinical outcomes and ensure a favorable prognosis.