**11. Controversial topics**

42 Front Lines of Thoracic Surgery

years/old. Thirty-six percent presented in acute renal failure, 33% were in atrial fibrillation, and 22% were insulin dependent diabetics. 57% were in NYHA Class IV heart failure with 41% in cardiogenic shock. Intra-aortic balloon pumps were used in only 20% of patients and 60% presented with significant mitral regurgitation. The timing of surgery was 14 ± 12 days from the acute event with 76% undergoing surgery within the first 3 weeks and 31% within the first 24 hours. A key point is again emphasizing the importance of early diagnosis and

Time to OR (d) 21 ± 13 11 ± 8 OR < 24hrs 18 % 43 % Pre-Shock 28 % 57 % Pre-sPAP (mmHg) 42 ± 11 56 ± 14 CPB time (time) 95 ± 28 126 ± 35 Post-IABP 39 % 90 % Post-LVEF (%) 45 ± 2 29 ± 2 Post-Op Renal Failure 25 % 66 %

Table 4. Italian Registry Data. Legend: CPB: Cardiopulmonary bypass, IABP: Intra-aortic balloon pump, LVEF: Left ventricular ejection fraction, sPAP: Systolic pulmonary artery pressures. Table adapted from Cerin et al. Inter Soc Cardiovasc Surg 2003;11:149-154

More recently, Mantovani et al reported their 19-year, single center, experience in 50 patients. Between 1983 and 2002, 50 consecutive patients with a mean age of 66 ± 9 years (range: 45-81) who presented with either anterior (n=30, 60%) or posterior (n=20, 40%) PI-VSDs. Patients developed their defects on average 4 days post-AMI with most within the first week (76%) and only 2 patients presenting after 2 days. Cardiac catheterization was performed in 98% of patients (51% single vessel disease, 35% double, and 14% triple). 56% of patients required a pre-operative IABP and 74% underwent emergent surgery on average 2 days after diagnosis of a PI-VSD. Operative mortality (within 30 days) was 36% with 6 dying in the operating room. Posterior defects were associated with 50% mortality versus 25% for anterior. Other univariate risk factors for early death included: emergent surgery (p=0.02); cross-clamp time >100 minutes (p=0.035); and delayed surgical intervention (>3 days post diagnosis, p=0.0055). Interestingly, in their experience factors not associated with operative mortality included: gender, extent of CAD (single vs triple vessel disease), need for CABG, age (>65 years), or the year of operation (before/after 1992). In a logistic regression analysis, only emergent surgery (odds ration: 10.23) and a delayed treatment (OR: 4.03) were the only predictors of early mortality. Long-term survival was 76.5 ± 7.8 and 56.1 ± 11.5% at 5 and 10 years. No obvious predictors of long-term survival were found in their analysis although patients with residual myocardium at risk from unrevascularized

In the GUSTO trial in which 41,021 patients were randomized to different strategies of reperfusion during AMI, 84 developed a PI-VSD. 34 of these were managed surgically, with 31 (90%) undergoing early treated and 3 (10%) undergoing delayed surgery. Survival in the surgical group was 53% at 30 days and 47% at 1 year. Conversely, for those treated medically, as an indicator of the lethality of this problem, survival at 30 days and 1 year was 6% and 3%, respectively (Crenshaw, 2000). All patients who presented in Class III or IV

regions tended to have a worse long-term prognosis (Mantovani, 2006).

heart failure died.

**Survivors (n=28) Death (n=30)** 

surgery before the onset of shock and organ failure (Table 4).

#### **11.1 Percutaneous closure devices**

Successful application of closure devices in children with congenital VSDs combined with the morbidity and mortality associated with surgical management has prompted enthusiasm for the use of percutaneous closure devices. The role of such devices has been proposed for both the primary closure of acute defects and to assist in the closure of recurrent or residual shunts (Shah, 2005).

While conceptually promising, initial experiences were discouraging and improvements in outcomes were not observed (Pienvichit, 2001). Difficulties in covering not only the actual defect, but also the residual necrotic myocardium predisposed to early recurrence. Early devices tended not to be large enough and were very difficult to position (or re-position if necessary).

In addition, the lack of a overall survival benefit further illustrates that clinical outcomes are not only dictated by closure of the VSD, but sometimes more importantly, a function of the extend of the myocardial infarction – which might be inherently so extensive as to preclude survival.

#### **11.2 Mechanical support**

As discussed, despite advances in surgical and post-operative management, operative mortality is still 10-60%. Even with early intervention biventricular failure is often a significant factor in early post-operative deaths. Short and long-term mechanical support, beyond intra-aortic balloon counterpulsation, is a reasonable option in patients with postoperative ventricular (left, right, or bi) failure and who are felt to be salvagable. Short-term support may be required as a bridge to recovery, while long-term device may be indicated for those with irreversible ventricular failure.

In cases in which there is extensive ventricular infarction/failure, associated free-wall rupture, or when there is excessive bleeding or tension from the ventriculotomy temporary left ventricular support should be considered. With LVAD inflow drainage from the left atrium, the LV is unloaded (i.e. 'atrialized') and may allow time for recovery/healing prior to exposing the injured LV to system pressures and contractile function (Firstenberg 2009).

Right ventricular support is also difficult following the acute volume/pressure overload of a PI-VSD with recovery unpredictable and potentially prolonged. Unfortunately, there is little data to support this use in this application other than clinical judgment and center experience.

Residual shunts after repair pose a unique challenge for patient's requiring mechanical support. Careful attention to left and right ventricular flows and pressures are critical to compensate for the residual shunt – and prevent worsening of over-circulation (Sai-Sudhakar, 2006). If residual shunts are significant then biventricular support may allow for a period of recovery and stabilization prior to an attempted repair in an otherwise very highrisk surgical patient.

The need for mechanical support, while attractive in unstable post-operative patients, is also associated with difficult problems. Often there is need for aggressive anti-coagulation, the need for multiple surgical procedures (i.e. device change-outs, explants, etc), and overall patient recovery is more difficult when tethered to external VAD controllers.

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A total artificial heart precludes native cardiac recovery and obligates transplantation, nevertheless, it may be an option with appropriate resources and experience in highly selected patient with few other comorbidities.

#### **11.3 Residual/recurrent defects**

Residual shunts are found in up to 25% of patients after definitive repair (Skillington, 1990). 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 (Jeppsson, 2005) and surgery is reserved for patients in heart failure failing medical management or those with large shunts (Qp:Qs>2.0) (Murashita, 2010). Because of the high operative mortality with repairing residual or recurrent shunts there has been interest, but limited success, with percutanous closure devices (Shah, 2005). Nevertheless, the role of percutaneous closure and the ideal devices are undefined (Pienvichit, 2001) and probably best reserved for use in those centers with extensive experience in the closure of congenital VSDs.
