Pericardial hernia: an unusual complication of convergent atrial fibrillation ablation.

A 59-year-old woman with highly symptomatic recurrent paroxysmal atrial fibrillation had failed antiarrhythmic therapy and pulmonary vein isolation. Owing to her large left atrial size and failed pulmonary vein isolation, she underwent the convergent atrial fibrillation ablation. A 3-cm subxiphoid incision was made at the central tendon of diaphragm above the liver, medial to the falciform ligament. Through this port, the VisiTrax ablation device (nContact, Inc., Morrisville, NC, USA) was advanced into the pericardial space and ablation was performed at the posterior left atrium and around the pulmonary veins. Subsequently, through an transseptal approach, endocardial lesions were created at the posterior antrum of the left superior pulmonary vein. Bidirectional block was confirmed across all four veins and a right-sided cavotricuspid isthmus line was created. Amiodarone was continued for 3 months. Four months after the procedure, she complained of constant bloating. Physical examination and routine laboratories were normal. Echocardiography showed an echogenic mass anterior to her heart. Computed tomography of her chest confirmed a diaphragmatic hernia with portions of greater omentum and transverse colon extending into the pericardium (Fig. 1). Laparoscopic hernia repair was performed. Diaphragmatic and pericardial openings were closed with figure of eight sutures and her abdominal symptoms resolved. Figure 1: CT chest showing diaphragmatic hernia with portions of greater omentum and transverse colon extending into the pericardium. Diaphragmatic hernia is rare and usually congenital or traumatic [1]. There are few case reports documenting diaphragmatic hernias following a pericardial window, pacemaker placement [2] and coronary artery bypass graft [3]. Being a minimally invasive procedure, the convergent ablation has minimal complications [4]. We have modified our technique to create a more posterior pericardial access site and we have not had any further cases of intrapericardial hernia. Alternatively, routine closure of the diaphragmatic access with a suture may also reduce the possibility of hernia formation.