Mid-Term Results of Reconstruction of the Right Ventricular Outflow Tract Using Cryopreserved Homografts

PURPOSE: Homograft benefits include excellent hemodynamics, resistance to infection, decreased thromboembolic events, ease of handling, and lack of need for anticoagulation. We examined the short and mid-term results of right ventricular outflow tract (RVOT) reconstruction using cryopreserved homografts. PATIENTS AND METHODS: From May 1998 to May 2005, 20 patients (male:female=10:10) underwent RVOT reconstruction using cryopreserved homografts. The median age was 23.8 years (range, 0.9 to 43.3 years) and the median body weight was 57kg (range, 7.3 to 80kg). Eighteen patients underwent re-operation after shunt or corrective operations. Homograft failure was defined as either re-operation for homograft replacement or patient death. Homograft dysfunction was defined as grade 3 or more than 3 of graft regurgitation and more than 40mmHg of transvalvular pressure gradient under echocardiographic examination. RESULTS: No operative mortality occurred and there were three major complications. Graft failure was observed in one male patient with tetralogy of Fallot. The 8-year freedom from graft failure was 87.5+/-11.7% and the 7-year freedom from graft dysfunction was 62.3+/-17.9%. Multivariable analysis revealed that the independent factor for graft dysfunction was age less than 10 years. In the analysis according to age group, the 7-year freedom from graft dysfunction in the group of patients older than 10 years was 100% and 25.0+/-21.7% in patients age 10 or younger (p= 0.03). CONCLUSION: Right ventricular outflow reconstruction using cryopreserved homografts provided excellent short and mid-term results in most patients in this study. However, in patients younger than 10 years old, homografts for RVOT reconstruction showed a high dysfunction rate at mid-term.

Reparación del miocardio mediante la terapia con células madre / Myocardial repair with bone marrow stem cell therapy

Para evaluar la efectividad del transplante de células madre en pacientes con infarto del miocardio e insuficiencia cardíaca crónica severa mediante técnicas de cardiología nuclear, se estudiaron 15 pacientes revascularizados: nueve (grupo I) recibieron células madre autólogas de médula ósea. Los 6 restantes correspondieron al grupo II (controles). Se les realizó evaluación clínica, ventriculografía radioisotópica y gammagrafía de perfusión con SPECT-gatillado (tecnecio-99m MIBI; protocolo de dos días: dipiridamol – reposo), antes y tres meses después del proceder. A los tres meses hubo mejoría clínica en el 89 por ciento de los pacientes del grupo I. La fracción de eyección de ventrículo izquierdo aumentó: de 32±9 por ciento a 44±13 por ciento (p=0.03; grupo I) y de 38±2 por ciento a 48±14 por ciento (p NS; grupo II). La velocidad máxima de llenado se incrementó de 120±11 a 196±45 VTD/seg (p=0.03; grupo I). El score sumado del dipiridamol disminuyó significativamente sólo en el grupo I (de 35±5 a 23±14; p=0.02). La mejoría de la perfusión estuvo relacionada con el sitio de implante en el 60 por ciento de los casos. Concluimos que el transplante de células madre de médula ósea es efectivo en pacientes con insuficiencia cardíaca crónica severa de etiología isquémica.