Cleft closure and undersizing annuloplasty improve mitral repair in atrioventricular canal defects
ABSTRACT Reoperation rates to correct left atrioventricular valve regurgitation after primary repair of atrioventricular canal defects remain relatively high. The causes of valvular regurgitation are likely multifactorial, and simple cleft closure is often insufficient to prevent recurrence.
To elucidate the mechanisms leading to regurgitation, we conducted hemodynamic studies using isolated native mitral valves. Anatomy of these valves was altered to mimic atrioventricular canal type valves and studied under pediatric hemodynamic conditions. The impact of subvalvular geometry, cleft closure, annular dilatation, and annular undersizing on regurgitation were investigated.
Papillary muscle position did not have a significant effect on regurgitation. Cleft closure had a significant impact on valvular competence, with reduction in regurgitation volume with increased cleft closure. Regurgitation volume decreased from 12.5 +/- 2.4 mL/beat for an open cleft to 4.9 +/- 1.9 mL/beat for a partially closed cleft and to 1.4 +/- 1.6 mL/beat when the cleft was completely closed. Annular dilatation had a significant impact on regurgitation even after cleft closure. A 40% increase in annular size increased regurgitation by 59% for a partially closed cleft and by 84% for a fully closed cleft. Reducing the annular size by 20% from the physiologic level decreased the regurgitation volume by 12% for a fully open cleft and by 58% for the partially closed cleft case.
Annular dilatation after primary repair has a potentially significant role in the recurrence of atrioventricular valve regurgitation. Reducing the annular size and restricting dilatation as an adjunct to cleft closure is a promising surgical approach in such valve anatomies.
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ABSTRACT: Background: Partial atrioventricular septal defect (P-AVSD) is a common congenital heart disease. Because of the presence of left and right atrioventricular valve deformities and the shift in the atrioventricular node and cardiac conduction bundle, the surgical repair of P-AVSD is difficult. This study was performed to compare the effects on the coronary sinus septum in the left versus the right atrium during surgical treatment for P-AVSD and report our experiences regarding the application of on-pump beating heart surgery under mild hypothermia for patients with P-AVSD.Materials and Methods: The effects of on-pump beating heart surgery were analyzed retrospectively in 87 P-AVSD patients. Of the 87 total patients, 84 with anterior mitral leaflet cleft underwent valvuloplasty and 3 underwent mitral valve replacement. Seventy-seven patients underwent tricuspid valve annuloplasty, 2 underwent tricuspid valve replacement, and 1 underwent left superior vena cava ligation, and 3 patients with atrial fibrillation were treated with radiofrequency ablation. Patients with an ostium primum atrial septal defect underwent autologous pericardial modified Kirklin repair. Of these, 46 patients had their coronary sinus septum separated into the left atrium and 41 had their coronary sinus retained in the right atrium. Fingertip oxygen saturation was compared between patients in whom the coronary sinus was separated to the left atrium and those in whom the coronary sinus was retained in the right atrium.Results: There was 1 postoperative early death (1.15%) due to respiratory failure, and 1 patient had a III degree atrioventricular block (1.15%) and underwent implantation of a permanent pacemaker. The fingertip oxygen saturation levels of the left atrium group were 96.81 ± 3.17 preoperatively, 95.37 ± 4.62 at 7 days postoperatively, and 94.53 ± 4.95 at 3 months postoperatively. Those of the right atrium group were 98.53 ± 2.84 preoperatively, 97.19 ± 3.57 at 7 days postoperatively, and 96.89 ± 4.19 at 3 months postoperatively. During the follow-up period, which ranged from 3 months to 7 years, the cardiac function was adequately restored.Conclusions: On-pump beating heart surgery under mild hypothermia is a safe and feasible method. The retention of the coronary sinus in the right atrium might maintain oxygen saturation.Heart Surgery Forum 10/2013; 16(5):E257-63. DOI:10.1532/HSF98.2013217
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ABSTRACT: Rapid preclinical evaluations of mitral valve (MV) mechanics are currently best facilitated by bench models of the left ventricle (LV). This review aims to provide a comprehensive assessment of these models to aid interpretation of their resulting data, inform future experimental evaluations, and further the translation of results to procedure and device development. For this review, two types of experimental bench models were evaluated. Rigid LV models were characterized as fluid-mechanical systems capable of testing explanted MVs under static and or pulsatile left heart hemodynamics. Passive LV models were characterized as explanted hearts whose left side is placed in series with a static or pulsatile flow-loop. In both systems, MV function and mechanics can be quantitatively evaluated. Rigid and passive LV models were characterized and evaluated. The materials and methods involved in their construction, function, quantitative capabilities, and disease modeling were described. The advantages and disadvantages of each model are compared to aid the interpretation of their resulting data and inform future experimental evaluations. Repair and percutaneous studies completed in these models were additionally summarized with perspective on future advances discussed. Bench models of the LV provide excellent platforms for quantifying MV repair mechanics and function. While exceptional work has been reported, more research and development is necessary to improve techniques and devices for repair and percutaneous surgery. Continuing efforts in this field will significantly contribute to the further development of procedures and devices, predictions of long term performance, and patient safety.Cardiovascular Engineering and Technology 09/2014; 6(2). DOI:10.1007/s13239-014-0196-4 · 1.41 Impact Factor
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ABSTRACT: OBJECTIVES: Recurrent left atrioventricular valve (LAVV) regurgitation after atrioventricular septal defect (AVSD) repair is a difficult technical issue. This study exposes the various techniques successively employed to repair the recurrent LAVV regurgitation and their different outcomes. Emphasis however will be put on the new technique used in our unit called cleft patch augmentation, which has been used continuously since 1998 in the anatomical context of normal papillary muscles (NPMs). METHODS: This is a retrospective follow-up study using a Cox regression model for risk analyses from November 1991 to July 2008, including 45 patients who underwent reoperation for LAVV regurgitation after AVSD repair. Of those, 3 patients were lost to follow-up; therefore , 42 patients were included in the study. With regard to the AVSD morphology, there were partial AVSD in 12, complete AVSD in 30. RESULTS: Age at the primary valve repair was 1.5 ± 2.1 years and the time span to the reoperation was 7.1 years in median (0.41–12.3 years). Age at the first reoperation was 10.1 ± 6.8 years. Median follow-up after the reoperation was 7.4 years. Three patients died in the follow-up period. Freedom from second reoperation at 10 years was 72.8% [59.5–89.0% of 95% confidence interval (CI)]. Of 37 patients with NPMs, freedom from reoperation at 10 years was 59.4% (37.2–94.7% 95% CI) in cleft closure group whereas, in the cleft patch augmentation group, it was 92.3% (78.9–100% 95% CI) (P = 0.04). Five patients required valve replacement. CONCLUSIONS: Surgical result for the redo LAVV repair had good outcomes. In the NPM group, the cleft patch augmentation technique had better results. Various techniques may have to be performed in combination according to the morphological features.European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 02/2015; DOI:10.1093/ejcts/ezv013 · 2.81 Impact Factor