Chapter 25: Surgical Treatment of Complications of Myocardial Infarction, Ventricular Septal Defect, Myocardial Rupture, and Left Ventricular Aneurysm

INTRODUCTION

Acute myocardial infarction can require surgical intervention for many reasons. Most commonly, patients may have coronary artery stenosis that may be amenable to coronary artery bypass grafting, either to halt the progress of the acute infarction, or to prevent subsequent angina, reinfarction, or death (see Chapters 20 to 25). Myocardial infarction can also result in refractory congestive heart failure and/or circulatory shock due to inability of the left and/or right ventricles to maintain the cardiovascular circulation. These patients may benefit from ventricular replacement therapy that include cardiac transplantation (see Chapter 61), extracorporeal membrane oxygenation (see Chapter 19) or placement of left and/or right ventricular assist devices (see Chapter 63). Acute myocardial infarction can have a number of other mechanical consequences that may need to be addressed surgically. These can include acute and chronic ischemic mitral regurgitation and even papillary muscle rupture (see Chapter 38) and functional tricuspid regurgitation (see Chapter 44). Three final and potentially catastrophic mechanical complications of acute myocardial infarction are addressed in this chapter and include postinfarction ventricular septal defect, cardiac rupture, and left ventricular aneurysm.

POSTINFARCTION VENTRICULAR SEPTAL DEFECT

Postmortem description of a postinfarction ventricular septal defect was first made in 1845 by Latham.¹ The first antemortem clinical diagnosis of a postinfarction ventricular septal defect was made in 1923 by Brunn.² Sager³ in 1934 established specific clinical criteria for diagnosis and associated postinfarction septal rupture with coronary artery disease.

The first successful surgical repair of a postinfarction ventricular septal defect was made in 1956 by Cooley in a patient 9 weeks after the diagnosis of septal rupture.⁴ The approach used was a right ventriculotomy similar to that used in patients with congenital ventricular septal defects. Thereafter the surgical mortality was sufficiently high that the strategy was to limit operation to those patients surviving for more than a month after acute septal perforation.⁵ Delayed surgery also had the advantage of allowing septal healing to facilitate more secure closure of the septal rupture.⁶ Heimbecker⁶ described septal defect repair through a left ventriculotomy in the zone of infarction combined infarctectomy and aneurysmectomy.⁷ Approaching the septal defect through the left ventricular infarct had distinct advantages of providing better exposure of the apical and inferior septum than did a right ventriculotomy. The left ventriculotomy also did not unnecessarily injure the otherwise critical right ventricle and allowed surgical remodeling of the infarcted portion of the left ventricle. Daggett et al⁸ in 1977 first reported a large series of 43 patients with improved surgical outcomes using a combination of infarctectomy and prosthetic patch material. In addition to the improved results overall, Daggett et al were able to successfully treat inferoposterior septal defects that previously had been problematic.^9-11 In 1995 David described 44 patients treated with infarct excluding patches with excellent mortality of 19% and unusually low incidence ...