Watchman封堵器左心耳封堵术的学习曲线分析

Learning curve assessment for left atrial appendage closure with the Watchman occluder

目的探讨Watchman封堵器左心耳封堵术的学习曲线。方法回顾性分析2015年12月至2018年6月杭州师范大学附属医院心内科同一操作医师连续实施的39例Watchman封堵器左心耳封堵术患者临床资料。按手术时间顺序分为A组(2015年12月至2016年10月)、B组(2016年11月至2017年9月)、C组(2017年10月至2018年6月),每组13例。选择手术时间、X线透视时间、术中造影时间、封堵伞释放时间、对比剂用量5项指标描述学习曲线,学习曲线的描绘采用累积和(CUSUM)分析法,同时结合并发症情况对学习曲线进行探讨。结果 39例患者的手术时间、X线透视时间、术中造影时间、封堵伞释放时间和对比剂用量的平均值分别为(108.74±48.73)min、(14.69±5.60)min、(38.10±16.18)min、(15.03±7.19)min和(251.28±94.23)ml。手术各时间节点及对比剂用量随手术例数的增加呈先下降后稳定趋势。三组患者的手术时间、X线透视时间比较,差异均有统计学意义(均P<0.05),而术中造影时间、封堵伞释放时间、对比剂用量比较,差异均无统计学意义(均P>0.05)。对手术时间、X线透视时间进一步分析,平均手术时间A组比B组、C组分别多71.84 min和105.00 min,B组比C组多33.16 min,差异均有统计学意义(均P<0.001)。平均X线透视时间A组比B组、C组分别多7.84 min、9.46 min,差异均有统计学意义(均P<0.001);B组与C组的平均X线透视时间比较,差异无统计学意义(P>0.05)。三组患者并发症发生率比较,A组、B组、C组发生率分别为30.77%、23.08%、15.38%,差异无统计学意义(P=0.273)。CUSUM学习曲线拟合优度R^2为0.9461,拟合方程∑_i(CUSUM值)=–0.0589X^2+2.2626X–0.835,拟合曲线在手术例数累积至第20例时,曲线相应点的切线斜率k变为负值。结论随着术者经验的积累,Watchman封堵器左心耳封堵术的安全性不断提高,累积手术例数达到20例时能够较好掌握此项技术,降低并发症发生率。

Objective To investigate the learning curve of left atrial appendage closure with Watchman occluder. Methods A retrospective analysis was carried out on the clinical data of 39 consecutive patients who underwent left atrial appendage closure by the same cardiologist from December 2015 to June 2018 in the affiliated hospital of Hangzhou Normal University. The patients were divided into three groups according to the procedure time, with 13 cases in each one, marked by A (from December, 2015 to October, 2016), B (from November, 2016 to September, 2017) and C (from October, 2017 to June, 2018). The time of procedure, X-ray fluoroscopy, intraoperative angiography, occluder release and the amount of contrast medium were recorded as evaluating indicators. The learning curve was indicated with the cumulative sum (CUSUM) analysis,and the curve-fi tting of CUSUM was designed through SPSS 18.0. This research also discussed the learning curve in combination with complications. Results The average time of procedure,X-ray fl uoroscopy,intraoperative angiography,occluder release were(108.74±48.74)min,(14.69±5.61)min,(38.10±16.18) min and (15.03±7.20)min, respectively;and the average amount of contrast medium volume was (251.28±94.23)ml. There were signifi cant diff erences in the time of procedure and X-ray fluoroscopy among the three groups (P<0.05), but there were no significant diff erences in the time of intraoperative angiography, occluder release and in the amount of contrast medium (P>0.05). With the increasing of surgical cases, all sectors of time nodes and the amount of contrast medium showed a trend of gradual stabilization after descending fi rst. The mean procedure time of the group A was 71.84min more than the group B and 105.00min more than the group C, with signifi cant diff erence (P<0.001). In the term of the mean X-ray fluoroscopy time, the group A was 7.84min and 9.46min more than the group B and C, respectively, but there was no signifi cant diff erence between group B and group C (P>0.05). From group A to group C, the complication rates declined dramatically (30.77%,23.08%, 15.38% for group A, B and C, respectively), although there were no signifi cant diff erences in complication rates among the three groups (P>0.05). The fitting equation was Σi (CUSUM)=–0.0589X2+2.2626X–0.835, and the R2 value was 0.9461. The curve slope turned into negative at the 20th case. Conclusions With the increasing of operator’s experience, the safety of left atrial appendage closure was increased. At least 20 cases are needed for cardiologists to master this technique, and further to reduce the rate of complications.