Occult cytomegalovirus infection presents anastomotic leakage after gastrectomy: Two case reports

Rationale: Cytomegalovirus (CMV) remains latent and causes disease in immunocompromised patients. However, surgical stress may also trigger reactivation without overt immunosuppression, leading to severe complications. Patient Concerns: Both patients developed life-threatening postoperative bleeding and anastomotic leakage after gastrectomy. The complications were difficult to resolve, leading to transfer to our hospital’s intensive care unit in the first case and repeated reoperations for leakage in the second case. Diagnoses: Refractory postoperative anastomotic leakage associated with occult CMV infection. Interventions: CMV infection was confirmed by whole-blood CMV PCR and treated with intravenous ganciclovir. Supportive measures, including endoscopic vacuum therapy, were performed to manage the anastomotic defects. Outcomes: In Case 1, leakage and bleeding persisted despite antiviral therapy, resulting in death from respiratory failure. In Case 2, antiviral initiation following CMV diagnosis led to significant improvement in anastomotic healing, and recovery without further major complications. Lessons: Occult CMV infection should be considered in patients with recurrent postoperative anastomotic leakage, even in the absence of overt immunosuppression. Early diagnosis and prompt antiviral-therapy may improve outcomes.