Vittorio Vanini

Repair of congenital malformations of the mitral valve: early and midterm results.

BACKGROUND The aims of this study were to determine early and midterm survival and freedom from reoperation, and to identify the predictors for poor postoperative outcome in children undergoing mitral valve (MV) repair owing to congenital malformations of the mitral valve. METHODS Between January 1990 and February 2001, 94 consecutive children with congenital MV disease underwent valve repair. The mean age was 5.2+/-3.3 years (range 20 days to 15 years). Twenty-five (26.6%) children were less than 1 year old. Isolated MV disease was found in 21 (22.4%) patients. MV stenosis was the predominant lesion in 21 (22.4%) patients with a mean left atrial to left ventricle diastolic peak gradient of 24.5+/-9.2 mm Hg. MV regurgitation was the predominant pathophysiology in 73 (77.6%) patients with a mean regurgitation grade of 3.3+/-0.7. RESULTS The hospital mortality was 8.5% (8 of 94). Three patients required permanent pacemaker implantation owing to complete atrioventricular block. Two patients underwent mediastinal exploration for significant bleeding. Postoperatively the echocardiography color Doppler study demonstrated a significantly lower mean end diastolic left atrium to left ventricle gradient 8.7+/-2.2 mm Hg (p < 0.001) in patients with MV stenosis and a mean regurgitation grade of 0.9+/-0.6 (p < 0.001) in patients with MV regurgitation. Actuarial survival and actuarial reoperation-free survival were 89.2% and 76.3%, respectively. Multivariate analysis demonstrated that age less than 1 year (p = 0.035), hammock MV (p = 0.0093), cardiothoracic ratio greater than 0.6 (p < 0.0001), and associated cardiac anomalies (p = 0.003) were strong predictors for poor overall freedom from reoperation and midterm survival. CONCLUSIONS Mitral valve repair for congenital mitral valve disease yields acceptable early and midterm mortality and reoperation rates. Strong predictors for poor overall freedom from reoperation and midterm survival were age less than 1 year, hammock MV, cardiothoracic ratio greater than 0.6, and associated cardiac anomalies.

Postoperative outcome in patients with anomalous origin of one pulmonary artery branch from the aorta

OBJECTIVES The aim was to review our experience with the surgical repair of the anomalous origin of one pulmonary branch from the aorta (AOPA). MATERIALS AND METHOD Between January 1991 and March 2002, eight patients with AOPA underwent surgical correction. Three patients presented isolated AOPA. Five patients presented right AOPA and three, left AOPA. Implantation of the AOPA to the main pulmonary artery was performed by: (I) direct anastomosis in two patients with left AOPA; (II) interposition of a synthetic graft in one patient with left AOPA; (III) employing an autologous pericardial patch in two patients with right AOPA; (IV) using an aortic flap in three other patients with right AOPA. The mean follow-up time was 37.7 months. RESULTS One patient died postoperatively due to progressive heart failure unresponsive to inotropic support. Early postoperative pulmonary hypertension crisis was identified in another patient. Within 1 year after surgery, the mean residual gradient across the anastomotic site at follow-up was 14+/-8 mmHg. The patient undergoing interposition of a synthetic graft presented a residual gradient of 29 mmHg and underwent reoperation at almost 2.5 years after the first correction. The residual gradient in patients undergoing correction according to technique I was 17+/-3 mmHg, and in patients undergoing implantation of the AOPA according to techniques III or IV was 9.5+/-4.6 mmHg (P=0.11). Similarly, the Tc-99m scintigraphy demonstrated that a lower lung perfusion (the lung perfused from the respective AOPA compared with the contralateral lung) in patients undergoing AOPA implantation according to technique I was 59+/-6(%) and in patients undergoing techniques III or IV was 72+/-4.5(%) (P=0.038). At follow-up, all patients were alive. CONCLUSION The AOPA from the aorta is a rare but important entity, necessitating a scrupulous preoperative and intraoperative evaluation. Patients presenting this anomaly may undergo correction using various surgical techniques with acceptable results. The techniques employing autologous tissues for enlarging and lengthening the AOPA seems to be associated with less restenosis at the anastomotic site, however, larger series of patients are required to confirm such outcome.

A possible cardioprotective effect of heat shock proteins during cardiac surgery in pediatric patients.

BACKGROUND Overexpression of heat shock proteins (Hsps) is associated to myocardial protection and it has been suggested that they could be a marker of cardiac preservation in conditions such as extracorporeal circulation. Aim of this study was to evaluate if cardioplegic arrest can modify the expression of Hsps in the heart and if this alteration is associated to cardiac preservation. METHOD The levels of Hsp 27, Hsp 60, and both the constitutive and the inducible form of Hsp 70 were measured in the cardiac tissue from right atrium of pediatric patients before and after aortic cross-clamping (ACC) during cardiopulmonary bypass surgery for correction of congenital heart disease (n=20). The quantitative evaluation of Hsps was made by Western blotting analysis after tissue extraction and protein separation. Hsp 72 mRNA expression was also evaluated in pre- and post-ACC samples of eight subjects by semiquantitative RT-PCR. Peripheral levels of Troponin I, Myoglobin, LDH, CK, CK-MB were measured in basal conditions and at 12 and 24h after cardiosurgery as markers of heart damage. RESULTS The cardioplegic arrest did not significantly modify the mean levels of all the Hsps measured. Hsp 72 levels increased after cardioplegia in the 40% of the patients and all Hsps in the 28% of subjects. The patients whose levels of Hsps are increased after cardioplegia are associated with lower post-surgery concentrations of all the markers of cardiac injury. CONCLUSIONS This observation suggests a relationship between the increase of Hsps and the reduction of cardiac injury.

Surgical closure of muscular ventricular septal defects using double umbrella devices (intraoperative VSD device closure)

OBJECTIVES Surgical closure of some muscular ventricular septal defects has been proven to be difficult. In order to simplify the surgical technique we have used intraoperatively Rashkind double umbrella devices to occlude muscular ventricular septal defects. METHODS On the basis of haemodynamic and echocardiographic study five children aged 4, 6, 7, 14 and 41 months were considered suitable candidates for intraoperative closure of muscular ventricular septal defects (midmuscular in three cases, apical in two) by Rashkind devices. Three of them had previously undergone pulmonary artery banding at 10, 11 and 41 days, respectively. During hypothermic cardiopulmonary by pass a delivery system was introduced across the tricuspid valve into the right ventricle and then passed through the ventricular septal defect; the distal umbrella of a 17 mm device was opened in the left ventricular cavity; a traction was applied to the introducer and the proximal umbrella was opened on the right side straddling the interventricular septum; the device was then secured on the right side by few stitches. In one case because of the wide diameter of the ventricular septal defect two umbrellas were used. The surgical procedure was completed with debanding and/or closure of other defects close to the aortic or tricuspid valve. RESULTS Immediate results, tested by epicardial or transesofageal echo, showed a minimal residual shunt in 4 patients and a moderate shunt in one. No early deaths occurred. A complete atrioventricular block developed in 1 patient who had an additional perimembranous defect closed with a prosthetic patch: a permanent pace maker was inserted 3 months after the operation. There was a late death for untractable right ventricular failure in 1 patient who had a large residual shunt erroneously considered moderate. In this patient, the size of the defect was underestimated both preoperatively then intraoperatively. The four survivors are doing well with no signs of hemodynamically significant residual shunts. CONCLUSIONS The use of Rashkind umbrella devices for closing intraoperatively muscular defects can be helpful to standard surgical techniques when technical problems make patch closure difficult. Its use avoid the need of left ventriculotomy. Careful definition of the size of the defect is mandatory to select suitable candidates.

Anomalous origin of the left pulmonary artery from the aorta. Our experience and literature review

Abstract Three patients with anomalous origin of the left pulmonary artery (AOLPA) from the aorta underwent surgical correction. Two patients presented with an isolated malformation and one with an associated ventricular septal defect. One of the patients with an isolated malformation presented with an AOLPA from the descending thoracic aorta. Implantation of the AOLPA to the main PA trunk was performed by direct anatomosis in two patients and by interposition of a synthetic graft in the other patient with AOLPA from the descending aorta. All patients survived the operation. Low cardiac output was identified in one patient. The mean residual gradient through the anastomotic site was 21 mmHg at follow-up. We found almost 72 cases with AOLPA reported in the literature with a high mortality rate in patients not undergoing surgery. The most frequently found associated malformation is tetralogy of Fallot and ventricular septal defect. AOLPA from the aorta is a rare but important entity, necessitating a scrupulous preoperative and intraoperative evaluation. Patients with AOLPA can undergo surgical repair with excellent results.

A Comparative Study of the Effects of Carbon Dioxide and Perfusion Rewarming on Limited Circulatory Occlusion During Surface Hypothermia, Under Halothane and Ether Anesthesia

Effects of the use of 5% CO(2) and surface-rewarming or perfusion- rewarming on safe total circulatory occlusion time, blood gases and carbohydrate metabolism were studied in 25 dogs subjected to surface hypothermia (18 C) and 30 minutes of circulatory occlusion under halothane or ether anesthesia. Under halothane anesthesia, all animals with 100% 0(2) developed motor disorders while one of five surface-rewarmed dogs and none of the perfusion-rewarmed dogs developed motor disorders with 5% CO(2). Under ether anesthesia, all were normal with either 100% 0(2) or when 5% CO(2) was added. Ventricular fibrillation occurred in one dog at 21C under halothane anesthesia with 5% CO(2). Blood lactate levels remained low through hypothermic procedures when 5% CO(2) was used. Perfusion rewarming had little effect on lactate levels. The use of 100% 0(2) resulted in slightly higher lactate levels, especially in the ether anesthetized group, but these levels still remained within the upper limit of the normal range. Significant differences in lactate levels between halothane and ether anesthesia suggest different mechanisms of tissue circulation and metabolism during hypothermia. Halothane anesthesia can be useful with the use of CO(2) for surface hypothermia with 30 minutes circulatory occlusion but is still inferior to ether.

A modified technique for repair of the anomalous origin of the right pulmonary artery from the ascending aorta

We report a modified technique of right pulmonary artery implantation to the main pulmonary artery with interposition of a tube created from the great arterial wall for an anomalous origin of the right pulmonary artery from the right lateral aspect of the ascending aorta. This technique offers extra autologous tissue length and reduced tension at the anastomotic site. It also offers the possibility to place the anomalous right pulmonary artery anterior to the ascending aorta, avoiding the aortic compression. This technique was employed successfully in a 15-week-old female.

Pulmonary artery banding and ventricular septal defect enlargement in patients with univentricular atrioventricular connection and the aorta originating from an incomplete ventricle

BACKGROUND In patients with univentricular atrioventricular connection and the aorta originating from an incomplete ventricle, subaortic stenosis is generally due to a restrictive ventricular septal defect (RVSD), that may be present at birth or develop after palliative procedures. In particular, a primary role in the genesis of the RVSD has been ascribed to pulmonary artery banding (PAB). The aim of this paper is to analyse the possible risk factors for the development of an RVSD, including PAB, and the results of one of the proposed procedures for treatment of this condition (RVSD enlargement). METHODS We retrospectively reviewed clinical records and outpatient records of 24 consecutive patients with univentricular atrioventricular connection and the aorta originating from the incomplete ventricle that received their first treatment at our institution from January 1991 to April 2000. The variables age, sex, weight, diagnosis, surgical procedures, associated anomalies, associated surgical procedures, were considered. RESULTS Four patients (16.7%) had absent left atrioventricular connection, seven (29.7%) had absent right atrioventricular connection and discordant ventriculo-arterial connection, and 13 (54.7%) had double inlet left ventricle and discordant ventriculo-arterial connection. Five patients (20.8%) had associated coarctation or hypoplasia of the aorta, and eight (33.3%) had pulmonary stenosis or atresia. Median age at the first operation was 7.5 days (range: 1-376). Median weight was 3.5 kg (range: 1.9-6.3). Seventeen patients underwent pulmonary artery banding, one underwent a Damus-Kaye-Stansel connection, one received a Glenn shunt and five a modified Blalock-Taussig shunt. Early mortality was 12.5%. The only variable associated with operative mortality was the presence of coarctation or hypoplasia of the aorta (P=0.004). Ten patients (41.6%) developed subaortic stenosis. None of the tested variables, including pulmonary artery banding, was associated with the development of subaortic stenosis. Subaortic stenosis was due to a restrictive VSD in eight patients, six of whom underwent direct VSD enlargement by muscular resection and are well at last follow-up (four complete repairs). None of the procedures was complicated by complete heart block. In two cases subaortic stenosis was treated by a Damus-Kaye-Stansel connection. A single patient died during follow-up, and 11 patients have achieved a complete one-ventricle repair. CONCLUSION In our experience, pulmonary artery banding was not associated with an increased risk of developing an RVSD. VSD enlargement proved to be safe and effective for treatment of subaortic stenosis due to an RVSD.

Surgical treatment of arrhythmias related to congenital heart diseases

BACKGROUND Supraventricular arrhythmias complicate operated and unoperated congenital heart disease, especially when atrial dilatation coexists. METHODS We evaluated the results of intraoperative ablation in a group of 23 patients with chronic supraventricular tachyarrhythmias (mostly intraatrial reentry) that were unresponsive to conventional medical therapy. All procedures were performed consecutively between September 1999 and November 2001. Ablation was done during redo operations (Fontan conversion to total cavopulmonary connection in 16 patients) in 18 patients and during primary surgical correction in 5 patients. The mean age at operation was 25 +/- 12 years (2 to 50 years). Cryoablation was done in 10 patients and radiofrequency ablation in 13 patients. Nineteen patients had ablation in one atrium and 4 had ablation in both atria. A generous atrial reduction was always performed at the end of the operation. RESULTS The operative mortality rate was 13% (3 patients) from causes unrelated to ablation. In 20 survivors, the ablation was effective immediately. Eight patients required a permanent pacemaker. During a mean follow-up of 22 +/- 4 months, atrial arrhythmias recurred in 25% (5 patients) and were controlled with medical therapy, whereas 1 patient required pacemaker implantation. CONCLUSIONS Intraoperative treatment of unresponsive atrial tachyarrhythmias associated with operated or unoperated congenital heart disease is feasible and the midterm results are encouraging.

A modified 'single patch' technique for complete atrioventricular septal defect correction

We propose a modified single-patch technique consisting in plication of the patch on the left side, which then is sutured with the free edge of the left atrioventricular valve. The proposed technique offers all the advantages of the single-patch technique and at the same time provides additional tissue for reconstructing appropriately the left atrioventricular valve in cases with leaflet tissue deficiency such as severely dysplastic valve, double orifice left atrioventricular valve. This modification augments the left atrioventricular valve tissue appropriately to the orifice size, promotes leftward displacement and improved coaptation with the mural leaflet.