Malcolm MacDonald, MD

Abstract

Anomalous aortic origin of a coronary artery (AAOCA) is a rare congenital heart defect that has been associated with myocardial ischemia and sudden death. Controversies exist regarding the diagnosis, treatment, and long-term recommendations for patients with AAOCA. The purpose of this study is to evaluate the medium-term results of surgical repair for AAOCA.From January 1999 through August 2010, 50 patients underwent surgical repair of AAOCA. The median age at surgery was 14 years (range, 5 days to 47 years). Thirty-one patients had the right coronary originate from the left sinus of Valsalva, 17 had the left coronary originate from the right sinus, and 2 had an eccentric single coronary ostium. Twenty six of the 50 patients had symptoms of myocardial ischemia preoperatively, and 14 patients had associated congenital heart defects. Repair was accomplished by unroofing in 35, reimplantation in 6, and pulmonary artery translocation in 9.There was no operative mortality. The median time of follow-up has been 5.7 years. Two patients were lost to follow-up, and 1 patient required heart transplantation 1 year after AAOCA repair. In the remaining 47 postoperative patients, all have remained free of cardiac symptoms and no one has experienced a sudden death event.The surgical treatment of AAOCA is safe and appears to be highly effective in eliminating ischemic symptoms. These medium-term results are encouraging and suggest that many patients may be able to resume normal activities.

View details for DOI 10.1016/j.athoracsur.2011.03.127

View details for Web of Science ID 000293221000050

View details for PubMedID 21718962

Abstract

Favorable outcomes in Ebstein's anomaly are predicated on tricuspid valve competence and right ventricular function. Successful valve repair should be aggressively pursued to avoid the morbidity of prosthetic tricuspid valve replacement. We report our experience with valve-sparing intracardiac repair, emphasizing novel concepts and techniques of valve repair supplemented by selective bidirectional Glenn (BDG).Between June 1993 and December 2008, 57 nonneonatal patients underwent Ebstein's anomaly repairs. The median age at operation was 8.1 years. All were symptomatic in New York Heart Association (NYHA) functional class II (n = 38), III (n = 17), or IV (n = 1). Preoperatively, 26 had mild or moderate cyanosis at rest. We used a number of valve reconstructive techniques that differed substantially from those currently described. BDG was performed in 31 patients (55%) who met specific criteria.No early or late deaths occurred. At the initial repair, 3 patients received a prosthetic valve. Four patients required reoperation for severe tricuspid regurgitation. Repeat repairs were successful in 2 patients. At follow-up (range, 3 months to 6 years), all patients were acyanotic and in NYHA class I. Tricuspid regurgitation was mild or less in 49 (86%) and moderate in 6 (11%). Freedom from a prosthesis was 91% (52 of 57).Following a protocol using BDG for ventricular unloading in selected patients with Ebstein's anomaly can achieve a durable valve-sparing repair using the techniques described. Excellent functional midterm outcomes can be obtained with a selective one and a half ventricle approach to Ebstein's anomaly.

View details for DOI 10.1016/j.athoracsur.2009.07.019

View details for Web of Science ID 000272029100037

View details for PubMedID 19932271

Abstract

Our approach to the extracardiac conduit Fontan operation has evolved over time from full-pump, to partial-pump, to completely off-pump. This study is designed to report our overall experience with the extracardiac conduit Fontan operation and to evaluate the evolution in bypass technique on postoperative outcomes.From September 1992 to April 2005, 285 patients, median age 4.5 years (1.4-44 years), median weight 16 kg (9.4-94 kg), underwent a primary extracardiac conduit Fontan procedure. Early and late outcomes were analyzed for the entire cohort and for 2 patient groups depending on whether an oxygenator was used in the bypass circuit (166 patients; 58%) or not (119 patients; 42%).Early failure (including death and takedown) occurred in 7 patients (2.5%). Prevalence of new early postoperative sinus node dysfunction necessitating a permanent pacemaker was 0.4%, and that of new tachyarrhythmias necessitating discharge home on a regimen of antiarrhythmia medications was 2.5%. Ten-year actuarial freedom from Fontan failure, new sinus node dysfunction necessitating a permanent pacemaker, and reoperation for conduit thrombosis or stenosis was 90%, 96%, and 98%, respectively. Fenestration rate was lower (P = .001) in the no-oxygenator group (8%) than in the oxygenator group (25%). Patients in the no-oxygenator group had lower intraoperative Fontan pressure (12.0 +/- 2.3 vs 13.5 +/- 2.4 mm Hg, P < .001), common atrial pressure (4.6 +/- 1.8 vs 5.3 +/- 1.8 mm Hg, P = .003), and transpulmonary gradient (7.5 +/- 2.1 vs 8.3 +/- 2.2 mm Hg, P = .013) than did the oxygenator group.The extracardiac conduit Fontan operation coupled with minimal use of extracorporeal circulation is associated with favorable intraoperative hemodynamics, low fenestration rate, minimal risk of thrombosis or stenosis, and minimal early and late rhythm disturbance.

View details for DOI 10.1016/j.jtcvs.2006.05.066

View details for PubMedID 17059923

Abstract

The use of a right ventricle to pulmonary artery (RV-PA) conduit in the Norwood procedure has been proposed to increase postoperative hemodynamic stability. A valve within the conduit should further decrease RV volume load. We report our clinical experience with this modification.From February 2002 through August 2005, we performed 88 consecutive Norwood procedures using RV-PA conduits. We used composite valved conduits made from cryopreserved homograft and polytetrafluoroethylene (PTFE) in 66 cases (54 pulmonary, 12 aortic homografts), other valved conduits in 14, and unvalved PTFE in 8 cases. Hospital survival was 88.6% overall and increased to 93.1% after the initial year. Early interventions were required in 18 patients (16 for cyanosis). Prestage II cardiac catheterization was performed at a mean age of 126 days. Mean Qp/Qs was 1, with mean aortic saturation 71%, mean O2 extraction 24%, and mean right ventricular end-diastolic pressure 9 mm Hg. Patient weight, use of an aortic homograft valve in the conduit, stage I palliation within the first year of our experience, and low O2 extraction and high transpulmonary gradient prestage II were risk factors for overall death. Early interventions were more frequent in aortic valve conduits compared with all other conduits.The valved RV-PA conduit was associated with low early mortality after the Norwood procedure. The majority of these patients had normal cardiac output and well-maintained RV function. There may be a higher risk for early conduit interventions and death when aortic valve homografts are used in the RV-PA conduit.

View details for PubMedID 16820644

View details for DOI 10.1016/j.jtcvs.2005.06.028

View details for Web of Science ID 000233896300046

View details for PubMedID 16308032

View details for Web of Science ID 000232956403391

Abstract

Laboratory and clinical data have confirmed the deleterious effects of deep hypothermic circulatory arrest. Long-term data and rigorous neuropsychiatric data are currently sparse, but that which are available show adverse outcomes following circulatory arrest, and therefore support the use of continuous perfusion techniques. There are no available long-term data on continuous perfusion techniques with respect to neurologic outcomes, but using these techniques the incidence of postoperative seizures or other neurologic events is rare. Currently available bypass systems and microsurgical techniques have allowed continuous flow and regional perfusion to become practical alternatives. Several innovative techniques for avoiding circulatory arrest during neonatal aortic arch reconstruction for univentricular and biventricular hearts are described. It would appear prudent and desirable to provide continuous perfusion now that long-term survival after repair of even the most complex cardiac anomalies including single ventricle defects is commonplace.

View details for PubMedID 11994869