EP427 - Right-Sided Colo-Pleural Fistula from Diverticulitis in a Medically Complex Patient

Purpose/Background: Colo-pleural fistulas are rare and potentially life-threatening complications, typically described in isolated case reports. They are most commonly associated with colonic malignancy, Crohn's disease, trauma with diaphragmatic injury, diaphragmatic hernia, or prior abdominal surgery. In rare instances, diverticular disease can lead to fistula formation, though these are typically left-sided due to the liver shielding the right diaphragm. Among patients with complicated diverticulitis, fistulas occur in approximately 2%, with colovesical and colovaginal being most common. Colo-pleural fistulas often present with vague or atypical respiratory symptoms, including dyspnea, chest pain, cough, and fever, and may be mistaken for primary pulmonary disease. This should be distinguished from colo-bronchial fistulas, which typically present with productive, foul-smelling sputum. Surgical management often includes colon and fistula resection, empyema evacuation with decortication, and diaphragmatic repair. Management remains challenging, particularly in patients with significant comorbidities who may not tolerate surgery.

Methods/Interventions: An 85-year-old male with cardiac amyloidosis, myelodysplastic syndrome, and heart failure with reduced ejection fraction presented with abdominal pain and dyspnea. Initial CT imaging revealed a right-sided subphrenic abscess with associated pleural effusion. Interventional radiology was consulted and performed CT-guided drainage with culture and drain placement, yielding purulent material. Patient was continued on IV antibiotics and abscess cultures grew Streptococcus anginosus. Given his last colonoscopy demonstrated diverticulosis, suspicion remained high for diverticular involvement as the source of infection.

Results/Outcomes: A multidisciplinary team including Surgery, Infectious Disease, and Cardiology deemed the patient a poor candidate for definitive surgical repair. He was discharged on hospital day seven with the drain in place and completed a 28-day course of IV antibiotics. Repeat CT imaging two months later demonstrated a persistent gas-containing pleural collection (8.2 x 2.4 cm) and a fistulous tract extending from the hepatic flexure through the diaphragm into the pleural cavity. Despite this, the patient remained clinically stable with improved respiratory symptoms. He continued to follow with Colorectal Surgery and Infectious Disease in the outpatient setting.

Conclusion/Discussion: Colo-pleural fistulas are exceedingly rare. The anatomical separation of the colon and pleural space, particularly on the right side where the liver provides a barrier, makes such fistulas particularly unusual. Interestingly, there are no published case reports of colo-pleural fistula in patients with Chilaiditi syndrome or hepato-diaphragmatic interposition. This case illustrates a rare instance of a right-sided colo-pleural fistula in the context of colonic diverticulitis and subphrenic abscess formation. The case underscores the diagnostic challenge of these fistulas, which may mimic pulmonary disease. Fistula interrogation with CT colonography and pleural fluid analysis are essential for diagnosis. While surgical repair remains standard, this case demonstrates that in select high-risk patients, non-operative management-using image-guided drainage, tailored antibiotic therapy, and close monitoring-can be successful. A multidisciplinary approach was critical to achieving an acceptable outcome in this complex patient.

CT imaging showing right-sided subphrenic abscess and associated pleural effusion.
CT imaging showing right-sided subphrenic abscess and associated pleural effusion.
Repeat CT imaging showing persistent right-sided colo-pleural fistula.
Repeat CT imaging showing persistent right-sided colo-pleural fistula.