**12. Conclusions**

to recovery before exposing the compromized left ventricle to systemic pressures and con‐

Right ventricular mechanical support is also difficult following the acute volume/pressure overload of a PI-VSD with recovery unpredictable and potentially prolonged. Unfortunate‐ ly, there is little data to guide decision making other than clinical judgment and center expe‐

Residual shunts after repair pose a unique challenge for patients requiring mechanical sup‐ port. Careful attention to left and right ventricular flows and pressures are critical to com‐ pensate for the residual shunt – and prevent worsening of over-circulation [39]. If residual shunts are significant then biventricular support, either with long-term ventricular assist de‐ vices or extra-corporeal membrane oxygenation, may allow for a period of recovery and sta‐ bilization prior to an attempted repair in an otherwise very high-risk surgical patient [44]. The decision to intervene surgically on residual shunts, because of the extremely high opera‐ tive mortality as discussed above, must clearly be made in the context of the overall clinical condition of the patient. Small defects can be managed medically and can be surprisingly

The need for mechanical support, while attractive in unstable post-operative patients, is also not without substantial risks. Often there is need for aggressive anti-coagulation, multiple surgical procedures (i.e. device change-outs, explants, re-operation for bleeding, etc), and overall patient recovery is more difficult when tethered to external VAD controllers. In addi‐

A total artificial heart, by definition, eliminates native cardiac recovery and mandates car‐ diac transplantation, nevertheless, it may be an option with appropriate resources and expe‐ rience in highly selected patient with few other comorbidities and in general, is probably a

Residual shunts are found in up to 25% of patients after definitive repair [43]. The etiology of residual shunts is either a missed defect at the time of initial repair, dehiscence of a patch (sewn to necrotic or friable tissue), or further extension of the initial defect. Fortunately, most residual shunts tend to be physiologically tolerated and spontaneous closure has been reported. Operative re-intervention is associated with a >60% mortality [27] and surgery is reserved for patients in heart failure failing medical management or those with large shunts (Qp:Qs>2.0) [34]. Because of the high operative mortality with repairing residual or recur‐ rent shunts there has been interest, but limited success, with percutaneous closure devices [41]. Nevertheless, the role of percutaneous closure and the ideal devices are undefined [35] and probably best reserved for use in those centers with extensive experience in the closure

tion, the risks for infectious complications with long-term support are considerable.

rience with management of acute post-cardiotomy right heart failure.

tractile function [19].

314 Principles and Practice of Cardiothoracic Surgery

well tolerated physiologically for years.

**11.3. Residual/Recurrent Defects**

poor idea.

of congenital VSDs.

Ventricular septal defects after acute myocardial infarction are rare events. With modern re‐ perfusion strategies, septal defects occur in up to 0.02% of acute myocardial infarctions. De‐ spite advances and experiences in the management of these complex patients, operative mortality still approaches 50% with major risks including cardiogenic shock, renal failure, right and/or left ventricular failure, size of the defect with degree of shunting, posterior/infe‐ rior locations, and residual post-repair shunting. While some patients may present late or benefit from watchful waiting and a delayed repair, typically surgical intervention is indi‐ cated prior to irreversible end-organ damage. Repair techniques emphasize closure of the defect and protecting the injured septum from left ventricular pressures while avoiding ad‐ ditional injury to the already compromised left and right ventricles. Post-operative manage‐ ment is typically challenging considering the inherent pre-operative biventricular dysfunction and often encountered end-organ dysfunction. Those who survive their initial event and operation tend to have favorable 5 and 10-year survivals.
