Faculty Bibliography

Reoperations during ventricular assist device (VAD) explantation and subsequent heart transplantation are difficult procedures because of dense adhesions, obliterated planes of dissection, and proximity of the right ventricle to the sternum. We present our approach for left VAD explantation to minimize potential complications that may occur during this procedure.

Despite advances in mechanical circulatory support, cardiogenic shock continues to have a high mortality. We reviewed our experience with pulsatile versus non-pulsatile temporary mechanical support at our institution to determine optimal strategy for survival. From January 2001 to December 2003, mechanical support for cardiogenic shock was instituted in 38 patients. Non-pulsatile devices (NP group) were used in 22 patients and pulsatile devices (P group) in 16 patients. Indications for the NP group were post-cardiotomy shock (PCS) in 17, myocardial infarction in 2, and isolated post-cardiotomy right ventricular failure in 3 patients. In the P group, 9 had the device placed for PCS, 3 for viral myocarditis, 1 after myocardial infarction, and 3 for right ventricular (RV) failure. Overall, bleeding, limb ischemia, and multi-system organ failure were higher in NP group with 5 weaned and 3 surviving to discharge (14%). In the P group, survivors included 7 weaned and 3 transplanted patients (63%). With the exception of isolated RV failure, we obtained a dismal survival result with ECMO/centrifugal circuits for treatment of cardiogenic shock. For refractory pump failure, improved survival was achieved by using intermediate-term pulsatile devices with early transition to a chronic device and/or heart transplantation.

Both heart failure (HF) and cardiac surgery with cardiopulmonary bypass result in a release of neurohormones, with a variety of physiologic effects. Administration of exogenous B-type natriuretic peptide (BNP) has beneficial hemodynamic effects and reduces the level of several neurohormones in HF patients. BNP is currently being investigated in the perioperative management of cardiac surgery patients and may be especially beneficial for patients with ventricular dysfunction, pulmonary hypertension, or renal dysfunction. Using a neurohormonal approach to supportive therapy may enhance future strategies for patients undergoing cardiac surgery, especially those at greatest risk for complications.

BACKGROUND: Patients with acute right ventricular (RV) failure after cardiotomy have a poor prognosis. We evaluated the surgical and long-term outcomes of patients with isolated RV failure that required right ventricular assist device (RVAD) support. METHODS: Between 1991 and 2002, a total of 30 patients received RVAD support for isolated RV dysfunction. We evaluated survival, duration of mechanical support, post-RVAD hemodynamics, and RV function. RESULTS: Right ventricular failure developed in patients after coronary artery bypass surgery alone or combined with valve surgery (12 patients), valvular surgery (5), ascending aortic replacement (6), heart transplantation (3), and pulmonary endarterectomy (4). Mean age was 58 +/- 15 years, and 17 (57%) were women. Surgery was emergent in 5 (73%) patients. Centrifugal pumps were used in 21, extra corporeal membrane oxygenation in 8, and as Abiomed pump in 1 patient. Overall, 17 (57%) patients died while receiving assist device support, 3 of sepsis, 2 of stroke, and 12 of inability to wean from the device. We successfully weaned RVAD support in 13 (43%) patients, with a median duration of support of 5 days (range, 2-8 days). Ten survived to hospital discharge. After RVAD removal, mean pulmonary artery pressure was 25.1 +/- 6.5 mmHg, cardiac output was 4.8 +/- 2.0 liters, and central venous pressure was 16.5 +/- 3.7 mmHg. Echocardiogram after RVAD removal showed normal RV function in 2 patients and in 11 patients demonstrated improvement. CONCLUSION: After cardiotomy, patients with RV failure who require mechanical support continue to have increased mortality. For patients successfully weaned from the RVAD, residual RV dysfunction is compatible with survival. More liberal use of RV mechanical support may be indicated for patients with acute RV failure.

BACKGROUND: The purpose of this study was to compare operative mortality and midterm outcome of patients with ischemic mitral regurgitation (MR) undergoing either coronary artery bypass grafting (CABG) alone or CABG with mitral valve (MV) repair. METHODS: From 1996 to 2001, 51 consecutive patients underwent CABG with MV repair for ischemic MR. All patients in this group were matched to similar patients with ischemic MR undergoing CABG alone during the same 6-year period using propensity analysis (considering 24 covariates, including severity of MR and New York Heart Association [NYHA] class). RESULTS: Propensity score matching yielded 51 closely matched control patients. Preoperative MR severity was 3+ or 4+ in 94% of CABG with MV repair and 96% of CABG-alone patients, and 86% of patients in each group were NYHA class III or IV. Operative mortality was 3.9% +/- 2.8% in both groups. Survival was also similar between CABG with MV repair and CABG alone at 1 year (84% +/- 5% versus 82% +/- 5%) and 3 years (70% +/- 7% versus 71% +/- 7% (p = 0.43). Among survivors, NYHA class improved at follow-up (50 +/- 20 months) from 3.4 +/- 0.7 to 1.7 +/- 1.0 for CABG with MV repair (p < 0.001) and from 3.4 +/- 0.7 to 1.8 +/- 1.0 for CABG alone (p < 0.001). CONCLUSIONS: Operative mortality, midterm survival, and late functional class were similar between two well-matched groups of patients undergoing CABG for ischemic MR, differing only in the addition of MV repair. Whereas MV repair can be added safely to CABG in this group of high-risk patients without increasing mortality, its impact on late survival and functional class may be limited.

BACKGROUND: The purpose of this study was to determine the incidence of neurologic hand complications after radial artery harvesting and to compare the harmonic scalpel versus conventional cold scalpel technique. METHODS: From 1995 to 2000, 786 radial arteries were harvested from 782 patients for coronary artery bypass grafting. From 1995 to 1997, the conventional cold scalpel technique was used (422 patients), and from 1998 to 2000, the harmonic scalpel was used (360 patients). Mean follow-up was 4.2 +/- 2.1 years and was 90% complete. Symptoms included thumb weakness or numbness, tingling, or pain in the hand. RESULTS: The incidence of neurologic hand complications was similar with both techniques (11.2% +/- 3.5% cold, 11.0% +/- 3.6% harmonic, p > 0.95), and in 19% (13 of 67 with symptoms) there was complete resolution within 1 year. Symptoms persisted long-term in 9.0% +/- 3.2% cold scalpel and 9.0% +/- 3.3% harmonic scalpel patients (p > 0.81), but were considered a "constant and significant source of discomfort" in only 0.6% +/- 0.9% cold scalpel and 1.4% +/- 1.3% harmonic scalpel patients (p > 0.41). CONCLUSIONS: The incidence of adverse neurologic outcomes causing significant long-term discomfort in the hand was low using either the cold scalpel or harmonic scalpel technique. However, a significant number of patients had neurologic hand symptoms in both groups, and this should be included when discussing operative risks with the patient.

BACKGROUND: The surgical treatment of mitral valve regurgitation (MR) at the time of aortic valve replacement (AVR) remains controversial. The purpose of this study was to evaluate the change in severity of MR following isolated AVR, and to determine survival benefit. METHODS: Between 1991 and 2001, 250 patients underwent isolated AVR; 196 patients had concomitant functional MR. Follow-up transthoracic echocardiography (TTE) was available on 107 patients, with a median of 818 +/- 752 days. Aortic valve was stenotic in 77 and regurgitant in 30 patients. RESULTS: Mean age was 67 +/- 15 years and 57 (53%) were male. Preoperative MR was trivial (1+) in 27 (25%), mild (2+) in 44 (41%), moderate (3+) in 29 (27%), and severe (4+) in 7 (7%). At follow-up TTE, MR improved by 1 or 2 grades in 48 patients (45%). Of patients with preoperative 2+ MR, 19 (43%) improved, 16 (36%) remained unchanged, and 9 (21%) worsened. Although some patients with preoperative 3+ MR exhibited improvement, 11 (38%) remained with moderate-to-severe MR. Of those with a preoperative MR of 4+, 3 (71%) improved, and 4 remained with 3-4+ MR. For patients with preoperative 1 to 2+ MR, survival at 3 years was 98% compared to 78% for those with 3 to 4+ MR (p = 0.038). CONCLUSION: Functional MR does not always improve after isolated AVR. Survival is lower for patients with preoperative 3 to 4+ MR. Moderate-to-severe MR should be repaired at the time of aortic valve surgery.