Interventricular septal hematoma detected by transesophageal echocardiography after congenital heart surgery in an infant: a case report

BACKGROUND: Interventricular septal hematoma is an extremely rare complication following congenital heart surgery. During cardiac surgery, interventricular septal hematomas can be detected only by intraoperative transesophageal echocardiography. Here, we report an interesting case of interventricular septal hematoma that was accidentally found in an infant following ventricular septal defect (VSD) closure. CASE PRESENTATION: Transesophageal echocardiography images were acquired from a 1-month-old boy after surgical repair of a large (6.5 mm) perimembranous outlet VSD with interventricular septal flattening. Surgical correction was performed with auto-pericardium and 7–0 Prolene sutures. The patient was successfully weaned from cardiopulmonary bypass, and transesophageal echocardiography showed no VSD leakage and good ventricular function. However, approximately 30 min later, two anechoic masses were found within the interventricular septum, which were suspected to be interventricular septal hematomas; the larger mass measured 1.51 [Formula: see text] 1.48 cm. The swollen interventricular septum showed decreased contractility and compressed both the right and left ventricles. However, there was no change in the size of hematomas or a significant hemodynamic instability for 30 min of observation. Therefore, expecting spontaneous resolution of the hematomas, the interventricular septum was not explored, and the patient was removed from cardiopulmonary bypass. On postoperative day 4, follow-up transthoracic echocardiography revealed thrombi filling the hematomas. The patient was discharged on postoperative day 15 and followed up with regular echocardiographic evaluations. CONCLUSIONS: We describe a unique case of interventricular septal hematoma after VSD closure. Surgical manipulation of perimembranous VSD and injury of the septal perforating artery may contribute to the development of an interventricular septal hematoma. Moreover, conservative treatment and serial echocardiographic evaluation generally show gradual hematoma resolution in hemodynamically stable patients. Pediatric cardiac anesthesiologists should be aware of this rare complication after VSD repair. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40001-021-00552-4.