Valve replacement in children

With increasing experience in the surgical management of children with congenital heart disease has come an increasing use of prosthetic valves. They have been employed in a wide variety of conditions ranging from simple congenital stenosis or incompetence to an essential part of repair of more complex disorders. As in adult cardiac surgery, there has been considerable debate over the exact prostheses that should be used in individual circumstances. As we point out in this article, experience has varied both geographically and with time. Our own experience at Great Ormond Street, for example, has been of initial satisfaction with results of mechanical valves followed by enthusiasm for, sequentially, the Hancock and the Ionescu prostheses. Now we have turned full circle and predominantly use mechanical valves, primarily owing to the extraordinary incidence of premature, degenerative calcification of bioprosthetic valves in children. The exact rates of degeneration of these valves are variable; thus it is difficult to relate prosthesis survival to the growth rate of the child. The experience with homograft valve replacements is encouraging, since they do not seem to degenerate so rapidly. Valve replacement in children carries a high risk. The younger the child, the higher the risk, with mitral valve replacement being the most dangerous procedure of all. We conclude that valve replacement in children is a procedure that should not be taken lightly and for which, at present, mechanical valves offer the best prognosis, despite the small risk of anticoagulation.

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Resumen Con la adquisición de una creciente experiencia en el manejo quirúrgico de niños con enfermedad congénita del corazón se registra un incremento en el uso de válvulas prostéticas. Tales válvulas han sido utilizadas en una amplia variedad de condiciones clínicas que van desde la simple estenosis o insuficiencia congénita hasta el reemplazo como parte esencial de la corrección de anomalías de mayor complejidad. En la cirugía cardiaca del adulto se ha presentado considerable controversia sobre el tipo exacto de prótesis que deba ser utilizado en cada circunstancia individual. Como lo señalamos en este artículo, la experiencia ha variado según factores geográficos y según la época. Nuestra experiencia en el Hospital for Sick Children de Londres, por ejemplo, ha sido la de una satisfacción inicial con los resultados de las válvulas mecánicas, seguida por entusiasmo por las prótesis de Hancock y luego de Ionescu y, ahora, dando un giro completo, volvemos a usar predominantemente válvulas mecánicas. Se discuten las razones para ésto, lo cual se relaciona primordialmente con la extraordinaria incidencia de calcificación degenerativa y prematura de las válvulas bioprostéticas en niños. Los índices exactos de degeneración de estas válvulas son variables, y por lo tanto es difícil establecer la relación entre la supervivencia de la prótesis y la tasa de crecimiento del niño. La experiencia con los reemplazos con homoinjertos valvulares es estimulante, puesto que éstos no parecen degenerar tan rápidamente. El reemplazo valvular en niños conlleva un alto riesgo. Entre más joven el niño mayor es el riesgo, con el reemplazo de la válvula mitral como el procedimiento más peligrosos entre todos. Hemos llegado a la conclusión de que el reemplazo valvular en niños no es un procedimiento que pueda ser emprendido con ligereza y para el cual, en la época actual, las válvulas mecánicas ofrecen el mejor pronóstico a pesar del riesgo menor que implica la anticoagulación.

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Résumé Avec l'extension du traitement chirurgical des cardiopathies congénitales de l'enfant, l'emploi chez lui des valves prothétiques s'est accru sensiblement. Elles ont été employées pour des altérations très diverses allant de la simple sténose ou insuffisance valvulaire jusqu'aux cardiopathies congénitales complexes ou leur emploi représente une part du traitement. Comme pour l'adulte le choix de la prothèse à employer pour une lésion déterminée a prêté à discussion. D'après l'expérience des auteurs leur choix s'est porté successivement sur les prothèses mécaniques, la prothèse de Hancock, la prothèse de Ionescu pour préférer à nouveau en dernier lieu les prothèses mécaniques. Les raisons de ce retour au choix initial sont exposées, la principale étant la fréquence extraordinaire des calcifications dégénératives précoces au niveau des bio-prothèses valvulaires chez l'enfant. Le taux exact de ce phénomène est variable mais il est difficile d'établir une relation de la survie de la prothèse et le taux de croissance de l'enfant. En revanche les tentatives d'emploi des homogreffes valvulaires sont encourageantes car la dégénéresence calcique paraît plus tardive. En fait, le remplacement valvulaire chez l'enfant comporte des risques importants. Plus jeune est l'enfant, plus grands sont les risques qu'il encourt, le remplacement de la mitrale représentant l'intervention la plus dangereuse. En conclusion: 1) le remplacement valvulaire chez l'enfant ne doit pas être entrepris à la légère; 2) pour le moment la prothèse mécanique offre le meilleur pronostic en dépit d'un faible risque d'anticoagulation.

     

Valve replacement in children

Between May 1979 and September 1998, 202 children underwent surgical treatment for valvular heart disease. Of these 23, who ranged in age from 25 days to 15 years, underwent valve replacement, including 1 reoperation. The valve replacement consisted of the aortic valve in 5 patients, the mitral valve in 3, the tricuspid valves in 9, including 5 systemic atrioventricular valves for atrioventricular discordance, the pulmonary valve in 6, 5 bioprostheses and 18 mechanical prostheses. There were 4 operative deaths, 1 hospital death and 3 late deaths. At the 10-years follow-up, the actual survival rate was 67.8%, the event free rate was 76.1% and the freedom from reoperation rate was 86.2%. Valve re-replacement was performed in only 1 patient due to a thrombosed tricuspid valve. These results suggest that there is a small risk of major complications and reoperation in children who undergo valve replacement, whether a bioprosthetic valve or a mechanical valve. The long-term results of younger patients should be followed more closely according to their growth.     

儿童心脏瓣膜置换手术及其疗效

目的探讨儿童心脏瓣膜置换手术及治疗效果。方法1990年1月至2002年12月，45例14岁以下儿童施行了心脏瓣膜置换手术。其中男26例，女19例。年龄3—14岁，平均10．8岁；≤10岁15例，10～14岁30例。包括先天性心脏瓣膜病32例，风湿性瓣膜病6例，心内膜炎3例，部分型房室管畸形修补术后二尖瓣关闭不全3例，室间隔缺损修补术后主动脉关闭不全1例。行二尖瓣置换23例，其中2例为矫正型大动脉转位行解剖位三尖瓣置换，主动脉瓣置换9例；二尖瓣与主动脉瓣双瓣置换4例；三尖瓣置换9例。5例使用生物瓣膜或同种主动脉瓣，余40例均采用机械瓣膜，包括进口双叶瓣34枚，进口单叶瓣3枚，国产单叶瓣7枚。结果本组手术死亡(术后30d内)2例，死亡率4．4％，均死于手术当日，1例因顽固性心律失常，1例术后低心输出量综合征。生存者随访8个月-12年，平均4．9年。4例晚期死亡，晚期死亡率9．3％。置入机械瓣膜者均采用华法林抗凝治疗，未发生血栓栓塞及抗凝相关并发症，病儿术后心功能均Ⅰ-Ⅱ级。结论儿童瓣膜病病人，大多数可以置入合适的成人型号人工瓣膜，保证其术后生长发育，减少二次手术。采用华法林进行抗凝治疗，经过平均4．5年随访，无血栓栓塞或抗凝有关的出血并发症发生，治疗效果较为满意。     

Aortic valve replacement with concomitant aortoventriculoplasty in children and young adults: long-term follow-up

Sixteen patients (9 male, 7 female) underwent aortic valve replacement (AVR) with a Konno aortoventriculoplasty at the University of Nebraska Medical Center from August, 1976, to May, 1986. There was 1 early death (6%), but no operative deaths have occurred since 1977. There was 1 late death from unknown cause 51 months postoperatively. One patient has been lost to follow-up. Long-term follow-up of 14 patients was 923 months (mean, 66 months; range, 9 to 120 months). Of the 16 patients, 12 (75%) had had previous cardiovascular procedures. A total of thirty-five operations, including the aortoventriculoplasties, were done in the 16 patients. Of the aortic valves inserted, 11 were tissue valves (Carpentier-Edwards, 10; Ionescu-Shiley, 1) and 5 were mechanical valves (St. Jude, 3; Bj?rk-Shiley, 2). Patient age at the time of aortoventriculoplasty ranged from 2 years 3 months to 24 years (median, 11 years 8 months). Size of the aortic annulus ranged from 10 to less than 21 mm (median, 16 mm). Valves inserted ranged from 21 to 29 mm; 13 (81%) of them were 25 mm or larger. In 2 patients, degenerated tissue valves were replaced with mechanical valves after 110 and 33 months. At present, all patients are in New York Heart Association Functional Class I. One female patient married and delivered a normal child approximately five years after AVR with a Carpentier-Edwards valve plus aortoventriculoplasty; she never received anticoagulant medications. We conclude that AVR with a concomitant Konno aortoventriculoplasty can be safely performed in the pediatric and young-adult age groups with satisfactory results for up to ten years.     

Valve reconstruction or replacement for long-term biopsy-induced tricuspid regurgitation following heart transplantation

Abstract  Tricuspid regurgitation following heart transplantation can become a severe problem in a subset of patients, where medical therapy fails. Operative findings are described and results of subsequent results with surgical intervention including repair and replacement are analysed. Although follow-up is short, tricuspid replacement seems superior to reconstruction following heart transplantation. Best results are obtained, if replacement is performed, before right ventricular function deterioates.     

Prosthetic heart valve replacement in children. Results and follow-up of 273 patients

We report the results and long-term follow up in 273 children (aged 2 to 16 years) who underwent prosthetic valve replacement. Mechanical valves (mostly Starr-Edwards) were used in almost all, and in 62 children more than one valve was replaced. Operative mortality was 4.7%. Actuarial survival curves (including hospital mortality) indicate a 86% survival rate at 5 years and 75% at 10 years. For isolated mitral valve prostheses (the largest subgroup), the figures are 87% at 5 years and 82% at 10 and 15 years. The main complication was thromboembolism, which occurred at a linearized rate of 2.7 per 100 patient-years. Actuarial curves indicate that 88% of patients are embolus free at 5 years, and 77% at 10 years. No patient with aortic valve replacement only had an embolism. Five of eight tricuspid prostheses thrombosed. Patients given aspirin and dipyridamole only did not have a higher rate of thromboembolic events than those given warfarin. There were five cases of endocarditis (two fatal) and four of dehiscence. No patient so far has needed replacement of a prosthesis because of somatic growth. Thus valve replacement can be performed with low mortality in children, and with satisfactory long-term survival. Thromboembolism remains a significant problem, although it appears to be less common than in adults. In this study, treatment with antiplatelet drugs only did not carry a higher rate of thromboembolic events than did treatment with warfarin.     

Long-term results of valve replacement in the right side of the heart in congenital heart disease--comparative study of bioprosthetic valve and mechanical valve

Valve replacements in the right side of the heart (TVR and PVR) were done on 16 patients with congenital heart disease, mainly tetralogy of Fallot and Ebstein anomaly. Including reoperations, 19 operations were performed on them and 20 artificial valves were inserted. Ten mechanical valves (7 St. Jude Medical valves, 3 Starr-Edwards valves) and 10 bioprosthetic valves (7 Carpentier-Edwards valves, 3 Ionescu-Shiley valves) were used. Age at valve replacement ranged from 9 to 52 years (mean 23.0 years), and the follow-up period was 1.28-19.8 years (mean 5.7 years). Including 2 sudden deaths, late death occurred in 4 patients, on all of whom mechanical valve replacements were done at the primary operation. Five-year survival rate of all patients was 76.4 +/- 12.1%, and 10-year survival rate was 63.6 +/- 15.4%. All the patients who received bioprosthesis at the primary operation survived at the time of this follow-up study. On the contrary, long-term results of mechanical valve was unsatisfactory with the 5-year survival of 62.5 +/- 17.1%. In spite of anti-coagulation therapy with warfarin, three patients with mechanical valve complicated thrombotic valves, which necessitated re-operations. Calcified bioprosthetic valve occurred in one patient with I-S valve 8.5 years after the implantation. Five-year complication-free rate was 87.5 +/- 11.7% for bioprosthesis, whereas it was 50.0 +/- 15.8% for mechanical valve (p less than 0.056). It is concluded that the bioprosthesis is the first choice for the valve replacement in the right side of the heart in congenital heart disease.     

Valve replacement in patients with huge heart]

In general, valve replacement for patients with big heart (cardiac-thoracic rate greater than 0.80) has been considered a contraindication. Mitral valve replacement was done in 11 patients with a C/T rate of 0.81 to 0.97. In addition, aortic valve replacement was performed in 2 patients and tricuspid valvuloplasty in 5. One patient died from low cardiac output after operation. The heart function of the survivor was improved from III or IV to II degree after operation. We consider that active pre- and postoperative management for preserving myocardial function and preoperative technique are important for the successful treatment of patients with huge heart.     

Valve replacement surgery in patients with end-stage renal disease: long-term results

BACKGROUND: The life expectancy of patients with chronic renal failure who are dependent on dialysis is very poor. This study was undertaken to determine time-related outcomes in dialysis patients requiring cardiac valve replacement. METHODS: From 1994 to 2001, 29 end-stage renal disease (ESRD) patients on hemodialysis (HD) program underwent 30 valve replacement operations: 29 received mechanical valves (97%), and one received bioprosthetic valves. The sites of valve replacement were 11 aortic (36.7%), 18 mitral (60%), and one both aortic and mitral (3.3%). Mean age was 42.46 +/- 14.26 years (range 17-75 years). Follow-up was completed in 28 patients (96.5%). RESULTS: Early postoperative mortality (in the first 30 days) was 3.4% (n = 1). The overall estimated Kaplan-Meier survival was 56.7% at 36 months, 46.7% at 60 months, and 43.3% at 96 months. HD program was discontinued for two patients after renal transplantation in the follow-up period. All patients, except the one with bioprosthesis, used warfarin sodium for anticoagulation and none of them had bleeding. One of the patients had a major cerebrovascular accident (CVA) and another one had a minor CVA at the follow-up (6.7%). CONCLUSIONS: Life quality is better and life expectancy is longer after valve replacement in ESRD patients who have valvular disease. Also, longer life expectancy increases the probability for finding donors for kidney transplantation.     

Internal hemipelvectomy and endoprosthetic pelvic replacement: long-term follow-up results

We report on our experiences with internal hemipelvectomy followed by an implantation of a endoprosthetic pelvic replacement (EPR) performed in 15 patients over a period of 15 years. Our primary aim was to determine the indications for this procedure because of its high rate of complications. Due to the malignant character of the disease and the biomechanical stress on the anatomical region, the demands on the surgeon are high. The most important factor is a sufficiently wide resection of the primary tumour because most are chondrosarcomata which do not respond to other therapies. In addition, the malignant character of the tumour has the greatest influence on the long-term results. Internal hemipelvectomy and endoprosthetic pelvic replacement are accompanied by a high rate of operative and postoperative complications. Nevertheless, nearly full anatomical and functional reconstruction can be obtained provided a medium level of function is accepted. Follow-up results of the remaining six still living patients were evaluated by means of three different scoring systems. All patients had only a medium score but emphasised subjective acceptance of the endoprosthetic pelvic replacement even when removal was necessary later on. Because of the lower functional outcome of alternative operative procedures such as pseudarthroses and arthrodeses and problems with the replantation of autoclaved autografts or implantation of an allograft, internal hemipelvectomy combined with endoprosthetic pelvic replacement is the treatment of choice for these specific acetabular lesions, provided a complete resection is feasible. Otherwise, an external hemipelvectomy is necessary because even alternative limb-salvaging procedures must incorporate the same complete resection of the tumour. In cases of metastatic lesions, internal hemipelvectomy and endoprosthetic pelvic replacement are indicated relatively because of the systemic character of the disease. The procedure should be considered only when resection of a solitary metastasis enables a cure and/ or prolongation of ilfe with an improved quality of life.     

The modified rectal bladder in children: long-term follow-up

Summary The criteria for evaluation of urinary diversion procedures in children must be strict since their life expectancy is long. Our experience with the modified rectal bladder in children with considerable follow-up periods is reported herein. All patients were continent by day and night. Urography studies revealed a normal upper tract in all cases. Three early complications were encountered among patients who had a submucous tunnel reimplantation. Reflux to the proximal colon or the kidneys was not demonstrated. The metabolic status and growth-rate patterns of these patients were within normal limits without alkaline therapy. All urine samples aspirated from the renal pelves were sterile. We conclude that a modified rectal bladder with a second ileal intussusception valve is the operation of choice whenever urinary diversion in children is indicated.     

Digital replantation in children: a long-term follow-up study

This paper reports a series of 14 cases of digital replantation in children who had had a total of 17 digits traumatically amputated. All but two digits survived, for an overall success rate of 88%. The length of follow-up was between 3 and 14 years (average 8 years). Sensory recovery of all digits was satisfactory. The mean growth rate of replanted digits relative to contralateral digits was 86%. Twelve cases had an excellent result, and one case had a good result. Digital replantation in children is recommended when feasible.     

Valve replacement after T-grafting: "beating heart surgery"

Patent internal thoracic and radial artery T-graft will adequately perfuse the heart during reoperation. Five of 1,023 patients with prior T-grafting had aortic (3) or mitral valve redo operations in which the heart was allowed to beat (after an initial dose of cardioplegia) during the operation without clamping the patent T-graft. Rapid resumption of cardiac function after one dose of cardioplegia and no intraoperative or postoperative evidence of myocardial infarction indicated adequacy of perfusion without apparent myocardial injury. This approach avoids injury to the T-graft from dissection and clamping, saves time, and simplifies the operation.