Short-term outcome of Polytetrafluoroethylene Membrane Valve versus Transannular Pericardial patch Reconstruction of Right Ventricular Outflow Tract in Tetralogy of Fallot : a Randomized Controlled Trial

Abstract Introduction: Reconstruction of right ventricular outflow tract during primary repair of tetralogy of Fallot often requires the placement of a transannular patch which results in pulmonary regurgitation (PR). We compared the short-term outcomes of bicuspid polytetrafluoroethylene membrane valve versus transannular pericardial patch reconstruction of the right ventricular outflow tract. Methods: Thirty consecutive patients undergoing primary repair of tetralogy of Fallot were randomly allocated to two groups - polytetrafluoroethylene valve (PTFEV) group (n=15) and transannular pericardial patch (TAP) group (n=15). The two groups had similar preoperative demographic characteristics. We compared the short-term clinical and echocardiographic outcomes between these groups. The transthoracic echocardiographic follow-up was performed at one week, one month and six months after surgery. Results: The PTFEV group had significantly lower central venous pressure in the immediate postoperative period compared to the TAP group (7.60±2.06 vs. 10.13±1.73, P=0.002). Extubation time was significantly shorter in the PTFEV group compared to the TAP group (12.93±7.55 hrs vs. 22.23±15.11 hrs, P=0.04). PR in the PTFEV group was absent in five patients at 24 hours post-surgery. At the study endpoint, PR was absent in six, trivial in one and mild in eight patients in the PTFEV group compared to TAP group, where all 15 patients had severe PR. Conclusion: The bicuspid polytetrafluoroethylene membrane valves significantly decrease the central venous pressure in the immediate postoperative period, facilitate early extubation and, thus, prevent ventilator-related comorbidities. They achieve a high degree of pulmonary competence and do not increase the right ventricular outflow tract gradient in short-term follow-up.

摘要 引言：法洛四联症（tetralogy of Fallot）一期修复术中重建右心室流出道（right ventricular outflow tract）时，通常需植入跨环补片（transannular patch），该操作可引发肺动脉反流（pulmonary regurgitation, PR）。本研究对比双叶聚四氟乙烯膜瓣（bicuspid polytetrafluoroethylene membrane valve）与跨环心包补片（transannular pericardial patch, TAP）行右心室流出道重建的短期预后效果。
方法：连续纳入30例行法洛四联症一期修复术的患者，按随机原则分为两组——聚四氟乙烯膜瓣组（polytetrafluoroethylene valve group, PTFEV组，n=15）与跨环心包补片组（n=15）。两组患者术前人口统计学特征无显著差异。本研究对比两组的短期临床与超声心动图预后指标，分别于术后1周、1个月及6个月行经胸超声心动图（transthoracic echocardiographic）随访。
结果：与跨环心包补片组相比，聚四氟乙烯膜瓣组术后即刻中心静脉压显著更低（7.60±2.06 vs. 10.13±1.73，P=0.002）。聚四氟乙烯膜瓣组拔管时间显著短于跨环心包补片组（12.93±7.55 h vs. 22.23±15.11 h，P=0.04）。术后24小时，聚四氟乙烯膜瓣组有5例患者无肺动脉反流。本研究终点时，聚四氟乙烯膜瓣组中6例患者无肺动脉反流、1例为微量反流、8例为轻度反流；而跨环心包补片组全部15例患者均存在重度肺动脉反流。
结论：双叶聚四氟乙烯膜瓣可显著降低术后即刻中心静脉压，促进早期拔管，从而预防呼吸机相关并发症（ventilator-related comorbidities）。该瓣膜可实现较高的肺动脉功能完整性，且在短期随访中未增加右心室流出道压差（right ventricular outflow tract gradient）。