Title : Intrapericardial incarceration of preperitoneal fat after subxiphoid pericardial window
Abstract:
Intrapericardial incarceration of preperitoneal fat is an exceptionally rare complication of subxiphoid pericardial window creation. We report a 70yearold Hispanic Mexican woman with morbid obesity (BMI 45 kg/m²), hypertension, type 2 diabetes, and hypothyroidism who developed recurrent pericardial effusion after COVID19 infection and laparoscopic cholecystectomy. A subxiphoid pericardial window was performed, but nine months later she presented with positional dyspnea, dizziness, and hypotension. Transthoracic echocardiography was unremarkable, yet noncontrast chest computed tomography revealed a 3cm defect in the central tendon of the diaphragm through which an 11 × 7 × 4 cm fat mass herniated into the pericardial sac, compressing the right cardiac chambers. Urgent median sternotomy permitted safe reduction of the incarcerated preperitoneal fat and primary closure of the diaphragmatic defect with interrupted 10 polyglactin (Vicryl) sutures, without mesh reinforcement. The postoperative course was uneventful; at fouryear followup the patient remained asymptomatic (NYHA I) with no recurrence. This case underscores that transthoracic echocardiography may miss extrinsic intrapericardial masses and that cross-sectional imaging is essential for diagnosis when patients with prior pericardial peritoneal communication develop unexplained positional cardiopulmonary symptoms. The pathophysiology likely involves iatrogenic creation of a diaphragmatic communication allowing gradual herniation of preperitoneal fat under increased intraabdominal pressure, resulting in dynamic cardiac compression. Surgical management should be individualized; median sternotomy provided optimal exposure for reduction and direct primary repair, offering durable long term outcomes for small, well defined defects. The report complies with the SCARE 2025 checklist, emphasizing transparent case reporting and ethical standards. This case adds to the limited literature on intrapericardial diaphragmatic hernias, highlighting a novel mechanism of obstruction and a successful operative strategy that may guide future management of similar iatrogenic complications.
