Abstract
Objective. To present the results of mitral valve replacement performed in early childhood at A.N.Bakoulev Scientific Center for Cardiovascular Surgery of the Russian Academy of Medical Sciences.
Material and Methods. 89 patients underwent mitral valve replacement surgery for the period from January 2003 to December 2012. The age of patients ranged from 10 months to 5 years, body mass – from 7,4 to 19 kg. The condition of all patients was evaluated to be serious or critical. In most cases mitral valve replacement was performed in the presence of congenital mitral valve regurgitation (61,8 %). All patients were operated under the conditions of cardiopulmonary bypass (87–309 min), hypothermia (24 °С) and hypothermic chemical cardioplegia. All children underwent implantation of mechanical valve prostheses: «St. Jude Medical» (n=68, or 76,4 %), «Carbomedics» (n=7, or 7,9 %), «MedIng» (n=2, or 2,2 %); «Medtronic» HALL (n=4, or 4,4 %), «ATS» (n=7, or 7,9 %), «Sorin» (1, or 1,1 %). The method of supra-annular mitral valve replacement was used in 11 (12,4 %) children. 68 (88,3%) patients were examined in a long-term follow-up after the surgery (from 3 months to 9 years). Somerville grading system was used for developmental and adapted physical activity assessment.
Results. The mortality rate in the short-term postoperative period was 12 (13,5 %) deaths. Complicated postoperative period was observed in 34 (38,2 %) children. 44 children (61,8 %) were classified as Somerville grade 1 and assessed their medical state as good, in 24 (35,3 %) patients parents observed certain reduction in exercise tolerance and susceptibility to acute respiratory tract infections. 2 children had symptoms of severe heart failure. Clinical-instrumental assessment in the long-term follow-up studies showed positive outcomes in all the children. Fluctuations of peak diastolic pressure gradient in prosthetic mitral valve ranged from 5 to 20 mm of mercury, of mean gradient – from 7 to 14 mm of mercury. Augmentation of diastolic pressure gradients in prosthetic mitral valve without its dysfunction was observed in 6 (8,8 %) patients. This phenomenon is related to children's growth, increase of body surface area. These patients underwent successful surgery for replacement of mitral valve prosthesis with a one of a larger diameter.
Conclusion. Mitral valve replacement surgery in early childhood should be considered the operation of choice when there is no possibility to perform valve-sparing surgery. All children who underwent implantation of mechanical valve prosthesis at an early become the candidates for reimplantation surgery. A narrow fibrous ring is not a contraindication for performing valve replacement surgery as it is possible to implant prosthetic valves in the supra-annular position. Adequate anticoagulant therapy is one of the main factors of durable valve prosthesis function. It is necessary to use individualized approach based on clinical assessment and instrumental examination to determine timing of reimplantation.
