Diastolic unloading and improved LV pump efficiency early after repair of the insufficient mitral valve.

BACKGROUND: This study aimed to evaluate the acute effect of mitral valve repair (MVR) on LV hemodynamics and geometry in patients with normal ventricular function. METHODS: In 10 patients with severe mitral regurgitation undergoing MVR, pressure-volume relationships were recorded before annuloplasty prior to and after hemodilution and after MVR during stable circulatory condition, using the conductance catheter technique (CC). Analyses were done off-line; volume calibration was based on data obtained after completion of valve repair (mean +/- s.d.). RESULTS: CC showed that only 61 +/- 15 % of left ventricular output was ejected into the systemic circulation, regurgitation volume being 39 +/- 15 %. MVR led to a reduction in LV stroke work index from 4.7 +/- 1.8 mm Hg x l x m (-2) at before valve repair to 2.2 +/- 1.0 mm Hg x l x m (-2) after surgery at unchanged cardiac index. LV diastolic filling parameters improved: LV relaxation time constant tau decreased from 52 +/- 15 to 37 +/- 11 ms and dP/dt (min) increased from - 873 +/- 231 to - 1286 +/- 283 mm Hg x s (-1). CONCLUSIONS: Despite cardioplegic arrest, MVR leads to acute improvement of diastolic LV function early after the operation. This may explain why valve repair has an acute positive effect in patients with impaired LV function.

Mitral-valve replacement in children under 6 years of age.

OBJECTIVE: In patients with congenital mitral-valve disease, reconstructive surgery is the primary goal. However, in cases with severely dysplastic valves or failed repair, mitral-valve replacement (MVR) is the only option. We analyzed, retrospectively, data of 35 patients younger than 6 years of age, who underwent MVR at our institution. METHODS: Between 1974 and 1997, 35 children underwent MVR. The ages ranged from 2.7 months to 5.5 years (mean=1. 9+/-1.7 years) and body weight varied between 3.2 and 16.7 kg (mean=8.2+/-4 kg). The main indication (57%) for valve replacement was severe mitral-valve insufficiency. Eighteen patients (51%) had undergone at least one previous reconstructive operation (mean=1. 46+/-1.86 years) before the MVR. In 29 cases (83%), mechanical prostheses were implanted. Six patients received a bioprosthesis. The size of the prostheses ranged between 14 and 27 mm. RESULTS: The overall hospital mortality was 17.1% (6/35), and decreased from 33 (1974-1985) to 11.5% (1986-1997). Seven children died late. The actuarial survival after 20 years was 51.2+/-13.3%. Eight patients (23%) required 10 reoperations (8.2%/100 patient-years). Freedom from reoperation at 10 years was 50+/-22%. Valve-related complications were thrombo-embolism (n=2; 1.6%/100 patient-years), hemorrhage (n=1; 0.8%/100 patient-years), structural deterioration (n=3; 2.5%/100 patient-years) and non-structural dysfunction (n=3; 2. 5%/100 patient-years). Follow-up is 96% complete, with a total of 122 patient-years (mean=4.2+/-4.7 years). Eighty six percent of the patients are in New York Heart Association (NYHA) class I, 95% have sinus rhythm and 59% do not need medication. All survivors, except for those who received a bioprosthesis, were placed on a regimen of Phenprocoumon (Marcumar((R))), aiming to maintain the International Normalized Ratio (INR) between 2.5 and 3.5. In one third of these children, self-management of oral anticoagulation was performed either by the patients or their parents. CONCLUSIONS: MVR in small children still carries a high risk. In our experience, the long-term results are satisfying. After failed reconstructive surgery, or as a primary procedure, we prefer mechanical prostheses. They are well tolerated and the incidence of anticoagulation-related complications is low.

Aortic valve replacement in children: are we on the right track?

OBJECTIVE: The choice of the ideal prosthesis for aortic valve replacement (AVR) in children is still controversial. Early degeneration of bioprostheses and the potential risks related to anticoagulation in the child have renewed the interest of many surgeons towards the Ross operation. This study concerns our 22-year experience with AVR in children. METHODS: Forty-six children, aged 4 months to 16 years (mean 11.6 years), had AVR between April 1974 and December 1996. Preoperative diagnosis revealed aortic regurgitation (AR) in 25 cases, aortic stenosis (AS) in ten, combined AS and AR in nine and LVOTO in two patients. Of the 46 patients, 26 had 37 previous procedures. Isolated AVR was performed in 19 cases, 27 children underwent 36 concomitant intracardiac procedures. Mechanical prostheses were implanted in 30 children, bioprostheses in eight, aortic homografts in three. Five patients underwent a Ross procedure. RESULTS: There was one hospital death in the latter group (2.1%). Six of seven late deaths occurred in patients who underwent complex intracardiac procedures (15.2%). Reoperation rate was 19.5% (n = 10), differentiating 16.6% for mechanical (5/30 patients) and 50% (4/8 patients) for bioprostheses. The mean follow-up period was 8.01 years, ranging from 0.45 to 21.66 years (304.04 patient-years). There was one hemorrhagic event (2.1%) due to anticoagulation, thrombosis of the mechanical valve occurred in two patients (4.2%). CONCLUSIONS: AVR can be performed with acceptable mortality rate and good long-term results in children. We perform the Ross operation only in selected cases. According to our experience, mechanical prostheses show excellent performances in children with a low incidence of complications related to anticoagulation.

Long-term results after repair of complete atrioventricular septal defects: analysis of risk factors.

BACKGROUND: We analyzed data from 320 patients to evaluate the impact of different preoperative, operative, and postoperative factors on the outcome after repair of complete atrioventricular septal defect. METHODS: Between October 1974 and December 1995, 320 patients with complete atrioventricular septal defect not associated with major cardiac anomalies were operated on. Two hundred seventy-four patients underwent total repair. Sixty-three patients (23%) were less than 6 months old. One hundred ninety-eight (72.2%) underwent primary repair. Seventy-six patients (27.7%) had a previous palliative operation. RESULTS: Operative mortality in patients who underwent primary repair decreased from 17.6% (1974 to 1979) to 5.0% (1990 to 1995) despite an increase in the number of patients younger than 6 months. In patients undergoing a two-stage procedure operative mortality was 3.9% (late mortality, 7.9%). Young age (<6 months) was an incremental risk factor (p = 0.008) for operative mortality in the early study period. Coarctation of the aorta (p = 0.02) and severe dysplastic left atrioventricular valve (p = 0.001) were associated with a higher risk for operative mortality. Freedom from reoperation at 10 years was 82.5% +/- 3.8%. CONCLUSIONS: In patients with complete atrioventricular septal defect, primary repair is the treatment of choice and can be accomplished with good results. In our experience over a period of more than 20 years, earlier date of operation, young age (<6 months), dysplastic left atrioventricular valve, and coexisting coarctation were incremental risk factors for hospital death. The presence of a previously placed pulmonary artery band did not alter the outcome of repair. The reconstructed atrioventricular valve shows a good and long-lasting performance.

The interrupted aortic arch: an overview after 20 years of surgical treatment.

OBJECTIVE AND METHODS: The records of 95 patients with interrupted aortic arch, admitted to our center from 1975 to 1995, were reviewed. We were particularly interested in the long term results and evaluated the impact of the preoperative state on the outcome after surgery. RESULTS: Using the 'Celoria and Patton' classification, 13% were type A, 84% type B and 3% type C. Among various associated anomalies were ventricular septal defects and left ventricular outflow tract obstructions, either subvalvular or due to a hypoplastic annulus or a bicuspid valve. We have also seen complex malformations such as truncus arteriosus communis, double outlet right ventricle and transposition of the great arteries. Preoperative neurological disorders, among them the Di George's syndrome, were found in 29% of the cases. Our long term results show 52 patients to be alive, of which 89% are in good clinical condition. Due to improved operative techniques and changes in the management of neonates respectively, early mortality was 17% between 1985 and 1995 compared to 42% between 1975 and 1985. Reoperations were necessary due to arch stenosis, compression of the bronchus or left ventricular outflow tract obstruction. CONCLUSIONS: Nevertheless, mortality after surgical repair of an interrupted aortic arch has dropped significantly and the preoperative condition plays an important role in the outcome. Sepsis, low output, low weight (under 2400 g), severe left ventricular outflow tract obstruction and complex malformations impeded surgery in 13% of cases. Immediate surgical intervention is the only therapy. Arch continuity and repair of associated anomalies could be achieved in the remaining collective. Most of the children have a good quality of life. The preoperative condition seems to influence late neurological disorders.