Creation of ventricular septal defects on the beating heart in a new pig model.

BACKGROUND/AIMS: So far, surgical and interventional therapies for muscular ventricular septal defects (mVSDs) beyond the moderator band have had their limitations. Thus, alternative therapeutic strategies should be developed. We present a new animal model for the evaluation of such strategies. METHODS: In a pig model (n = 9), anterolateral thoracotomy was performed for exposure of the left ventricle. mVSDs were created under two- and three-dimensional echocardiography with a 7.5-mm sharp punch instrument, which was forwarded via a left ventricular puncture without extracorporeal circulation. RESULTS: Creation of mVSDs was successful in all animals (n = 9) confirmed by echocardiography, hemodynamic measurements and autopsy. The defects were located in the midmuscular (n = 4), apical (n = 1), inlet (n = 2) and anterior part (n = 2) of the muscular septum. All animals were hemodynamically stable for further procedures. The diameter and shunt volume of the mVSDs were 4.8-7.3 mm (mean: 5.9 mm) and 12.9-41.3% (mean: 22.1%), respectively. Autopsy confirmed in all animals the creation of a substantial defect. CONCLUSION: The described new technique for creation of an mVSD on the beating heart in a pig model is suitable for the evaluation of new therapeutic strategies for mVSD closure.

Surgical management in paediatric patients with left abnormal subclavian artery and right aortic arch.

Left abnormal subclavian artery and right aortic arch is described as a rare cause of dyspnoea and dysphagia in paediatric patients. The optimal surgical management of such cases is not clearly established. We propose a single-stage repair by transection of the patent ductus arteriosus or ligamentum arteriosum and an additional transection of the left abnormal subclavian artery with reimplantation into the common carotid artery.

Borderline hypoplastic left heart malformations: Norwood palliation or two-ventricle repair?

BACKGROUND: Patients with hypoplastic left heart syndrome (HLHS) and associated malformations undergo Norwood palliation or potentially a two-ventricle repair. METHODS: Since 8/99, 8 patients with typical HLHS and two with DILV underwent Norwood/Fontan palliation (group I). Three other patients (group II) had two-ventricle repair. Anatomy was: aortic atresia, coarctation, unrestrictive VSD (patient 1), hypoplastic mitral and aortic valve, arch and LV, coarctation (patients 2 and 3). Surgical procedures were Norwood arch reconstruction with either Rastelli operation (patient 1) or ASD-closure (patients 2 and 3). RESULTS: Operative mortality in group I was 1/8 (day 22; RV-failure). Two patients died before Glenn (sepsis, RV-failure). Six patients underwent Glenn procedure successfully. No patient died in group II. Echocardiography after 13 +/- 7.4 months showed mild homograft dysfunction (patient 1) and an LVOT-gradient of 20 mmHg (patient 3). Clinical condition of all survivors in both groups is good. CONCLUSION: Some anatomical subsets of HLHS with borderline mitral valves and small left ventricles may undergo two-ventricle repair despite severe LVOTO. Mortality and morbidity seem to be lower, but selection criteria are so far not defined.