Impella Support for Surgical Ventricular Septal Defect Repair

Abstract

Acute postinfarct ventricular septal defect (VSD) is associated with high mortality due to a combination of cardiogenic shock and a complex repair in recently infarcted fragile myocardium.1Although the Impella heart pump is established as support for cardiogenic shock, it is relatively contraindicated in postinfarct VSD because of potential right-to-left shunt or stroke due to VSD tissue-related embolus. On autopsy, early repair is technically difficult due to tissue friability and as a result, 38% of surgically repaired patients have evidence of recurrent interventricular septal rupture.2Delayed surgical repair (>7 days) is associated with superior survival - 54% after 7 days versus 18% prior - but hemodynamic instability may prevent delay.3Case reports have shown successful early left ventricular unloading with Impella patients with acute postinfarct VSD before surgical repair.4,5We discuss our algorithm for pre-repair Impella support in which we stratify pre-repair support based on the Qp/Qs ratio. For VSD with Qp/Qs >2.5, we use a preoperative Impella heart pump and have not demonstrated reversal in the left-to-right shunt on echocardiography and/or stroke. Our findings are consistent with theoretical models of unloading as demonstrated by shifts in pressure-volume loops.6