右心室流出道的处理方法与法洛四联症矫治术后右心室功能的相关分析

目的 评价法洛四联症(TOF)右心室流出道(RVOT)处理方法与矫治术后右心功能变化的关系,以期提高矫治手术的中、远期效果.方法 2003年1月至2006年1月,125例TOF患儿接受矫治手术,其中男66例,女59例;手术年龄1～5岁,平均(3.4±1.1)岁;体质量7～26 kg,平均(15.2±5.7)kg.对照组选择20例同龄健康儿童.RVOT处理方法包括跨肺动脉瓣环补片加宽(M1组)67例,右心室漏斗部补片加宽(M2组)6例,经右心室切口非补片修复(M3组)18例,经右心房-肺动脉切口非补片修复(M4组)34例.采用脉冲多普勒(PDE)和组织多普勒超声心动图(TDI)评价右心室功能,选择三尖瓣环收缩期移位(TAPSE)、右心室心肌作功指数(MPI)作为右心室收缩功能指标,测定的三尖瓣瓣环处舒张早期峰速(Em),舒张晚期峰速(Am),计算Em/Am和E/Em比值作为右心室舒张功能指标.计量资料采用单因素方差分析,单因素分析有统计学意义的变量纳入logistic回归分析.计数资料采用x2检验.结果 术后5年随访检查心脏超声发现,M1和M2组的MPI和E/Em显著高于M3和M4组.单因素分析显示,术前Nakata指数、既往分流手术、手术方式、肺动脉瓣反流和术后QRS时间是影响术后MPI的危险因素;术前Nakata指数、手术方式、肺动脉瓣反流和术后QRS时间是影响术后E/Em的危险因素.二元logistic逐步回归分析结果显示,手术方式和术后QRS时间是影响术后MPI的独立因素;术后肺动脉瓣反流是影响术后E/Em的独立因素.结论 TOF术后右心室功能降低与RVOT处理方法有关,舒张功能的降低与术后肺动脉瓣的反流有明显的相关性,收缩功能的降低与手术中应用补片加宽右心室流出道和术后的QRS时间有明显的相关性.心脏超声多普勒技术在测定TOF术后右心室功能和评价术后中、长期疗效有重要的指导意义.     

食管超声心动图评价围术期儿童法洛四联症的右室流出道

目的 运用经食管超声心动图（TEE）对儿童法洛四联症（TOF）的右室流出道（RVOT）情况进行围术期评价。方法 32例TOF病儿体外循环前后分别进行TEE检查，年龄4个月～15岁8个月，平均4．0岁。结果 术前32例均TEE诊断为TOF。31例行根治术，1例行B-T分流术。RVOT扩大补片15例；跨肺动脉瓣环补片（TAP）16例，包括4例切除肺动脉瓣，2例带瓣移植物重建RVOT。术后TEE诊断RVOT残余梗阻5例（16．1％），与是否采用TAP无关（X^2=1．115，P=0．291）。肺动脉反流（PR）16例（51．6％），采用TAP比扩大补片术后更易出现PR（X^2=14．212，P=0．000）。保留原肺动脉瓣可减轻术后PR程度（X^2=5．915，P=0．015）。带瓣移植物重建RVOT可减少术后PR（X^2=8．163，P=0．004）。结论 术前TEE可明确诊断TOF，术后TEE可评价不同手术方法对于RVOT的效果。     

Iatrogenic right ventricular failure in tetralogy of Fallot repairs: reappraisal of a distressing problem

A patient with tetralogy of Fallot experienced isolated right ventricular failure when the right coronary artery was occluded by an encircling suture at the time of closure of the ventricular septal defect. Recognition and correction of the problem allowed weaning from cardiopulmonary bypass and an uneventful recovery. Because ventricular septal defects in tetralogy of Fallot are usually anterior and subaortic, injury to the right coronary artery, in close proximity to the superior aspect of the defect, is a potential danger. When isolated right ventricular failure occurs immediately after repair, suture occlusion of the right coronary artery should be considered as a possible cause.     

Evidence for palliative enlargement of the right ventricular outflow tract in severe tetralogy of Fallot

Objective: If the pulmonary artery (PA) tree in patients with Fallot's tetralogy (TOF) is extremely hypoplastic, a shunt procedure may be difficult and not desirable because of side-effects. Moreover, the failing catch-up growth of the pulmonary annulus is well known. In patients with a severe form of TOF, we performed palliative transannular patching of the right ventricular outflow tract. The early and long-term follow-up was evaluated. Methods: Eleven patients (93 days (10–245 days); 3.5±0.7 kg (2.5–4.3 kg)) had highly symptomatic TOF (Hb: 18±2 g/dl, SO₂: 68±11%); angiographic diameters: RPA: 4.1 mm (2.5–6.4 mm), LPA: 3.4 mm (1.6–7.0 mm), PA trunc: 4.4 mm (2.5–7.0 mm). All 11 underwent transannular enlargement of the right ventricular outflow tract without closure of the ventricular septum defect. A PA index (cross-sectional area of the pulmonary arteries to BSA) was used to compare pre- and postoperative data. For follow-up, the patients were repetitively examined clinically and echocardiographically. Results: Preoperative PA index was 87±40 mm²/m² (normal: 330±35 mm²/m²). Postpalliation angiograms (age: 10–14 months) demonstrated a significant catch-up growth in nine patients (PA index from 99±40 to 310±54 mm²/m²) and inadequate growth in two patients (PA index 63 and 115 mm²/m²). Perioperative mortality was zero. Ten patients (43 months; 6–105 months) underwent elective repair. Six patients received pulmonary homograft valves (6–15 years after repair) because of severe pulmonary valve insufficiency and severe RV dilation. Complications: One patient died 10 months postpalliation due to pneumonia, one patient received a pacemaker after repair and died (2 months post-repair) due to pacemaker failure, a 5-year-old patient died 1 month after repair due to sepsis. All eight long-term survivors (12–17years) are in excellent clinical condition. Echocardiography revealed good RV function and near normal diameters at peak systolic pressures between 25 and 50 mmHg. Only one patient developed brady-arrhythmia; a pacemaker was implanted 8 years after repair and 2 years after homograft implantation. Conclusions: In a very severe form of TOF, palliative right ventricular outflow tract construction may provide the potential for complete repair. In the presented high-risk patient group, mortality was not related to the hypoplastic pulmonary arteries. Obviously, all patients need pulmonary valve implantation in the long run.     

Late right heart reconstruction following repair of tetralogy of Fallot.

Twenty-two symptomatic patients underwent a total of 28 reoperative procedures after initial surgical repair of tetralogy of Fallot. Sixteen of the patients were considered to have unfavorable anatomy of the right ventricular outflow tract (RVOT) or pulmonary artery at the time of initial repair. Pulmonary or tricuspid valve replacement, or replacement of both valves, utilizing a xenograft bioprosthesis was performed in 1 of the 22 initial repairs, 7 of the 22 first reoperations, and 5 of the 6 second reoperations. Ultimately, 14 patients received transannular RVOT patches. The interval between the first and second reoperations for 6 patients who required 2 late reconstructive procedures was 5.8 years. No operative deaths occurred. There were 2 late deaths (1 sudden and 1 due to aspiration). Actuarial survival probability (+/- standard error of the mean) 16 years after initial repair was 72 +/- 21%. Eighteen of the 20 current survivors in the present series are completely asymptomatic without physical restrictions; the other 2 are considered to be in New York Heart Association Functional Class II. No xenograft bioprosthetic dysfunction has occurred to date, but cumulative valve follow-up is limited (13 patient-years). In selected patients, earlier pulmonary or tricuspid valve replacement or replacement of both of these valves can provide some degree of protection against recurrent deterioration.     

The dimensions of the right ventricular outflow tract and pulmonary arteries in tetralogy of Fallot and pulmonary stenosis.

Studies were undertaken of the cineangiograms in 196 consecutive patients entering two institutions with tetralogy of Fallot and pulmonary stenosis, none of whom had previously undergone a surgical procedure. The median age of the patients at the time of the study was 5.9 months. The diameters of the right ventricular infundibulum, pulmonary trunk, and the entirety of the right and left pulmonary arteries were measured (in millimeters), corrected for magnification, and expressed in standard deviation units (Z-values). The median values of the cineangiographically determined diameters of the right ventricular infundibulum and pulmonary trunk were smaller than those of 95% of normal individuals. The median values throughout the right and left pulmonary arteries were within the range of normal. Those of the distal branches of both the right and left pulmonary arteries were similar to the mean values in normal individuals. However, great variability of the dimensions between individuals, and along the pathway in individuals, characterized patients with tetralogy of Fallot. Diffuse narrowing of the pathways both proximally and distally was uncommon. The relation between the diameters of the pulmonary "anulus" and of the distal pulmonary trunk and origin of the left pulmonary artery explained the difficulty of extending an enlarging patch into a wide area distally in some patients.