探讨应用3D打印心血管模型在Liwen术式治疗梗阻性肥厚型心肌病术前评估中的可行性及有效性。

回顾性研究2018年10月至2019年5月于空军军医大学西京医院诊治的梗阻性肥厚型心肌病并施行Liwen术式治疗的患者8例。术前采集患者CT检查影像学数据，将其导入Mimics软件进行重建，结合3D打印技术制作患者全心解剖模型，即进行术前影像学评估。患者均在超声引导下行经皮心肌内室间隔射频消融术，经胸超声行术中监测并评价手术情况，术后1、3、6个月及每年进行随访观察，结合影像学及3D打印技术进行术后评估。采用配对t检验比较术前术后左心室射血分数、二尖瓣反流量的差异，采用Wilcoxon符号秩检验比较术前术后静息和负荷时左心室流出道压差数据差异。

8例患者成功施行了Liwen术式，3D打印模型能够准确复制患者心脏的个体化解剖结构，辅助Liwen术式治疗梗阻性肥厚型心肌病术前评估，术中手术情况和术后3D打印模型与实际手术情况相符。与术前比较，术后6个月左心室射血分数增加［（58.36±6.21）% vs （46.25±7.62）%］，最大室间隔厚度减小［（13.92±3.56）mm vs （25.42±4.93）mm］，二尖瓣反流量减小［（1.04±0.41）ml vs （10.14±3.72）ml］，差异均具有统计学意义（t=7.998、14.539、4.726，P=0.015、0.005、0.041），静息时和负荷后左心室流出道压差均减小［90.45（90.00，110.00）mmHg vs 7.00（6.00，10.00）mmHg；141.00（89.25，150.00）mmHg vs 16.50（15.00，17.85）mmHg］，差异均具有统计学意义（Z=2.521，P=0.012；Z=2.521，P=0.012）。术前纽约心脏协会心功能分级Ⅲ级者5例，Ⅳ级者3例，术后6个月纽约心脏协会心功能分级Ⅰ级为6例，Ⅱ级2例。

3D打印技术辅助Liwen术式术前评估对治疗心肌肥厚具有可行性与有效性。

To explore the feasibility and validity of preoperative evaluation of Liwen procedure for obstructive hypertrophic cardiomyopathy using 3D printing cardiovascular model.

A retrospective study was conducted on eight patients with obstructive hypertrophic cardiomyopathy who were treated at Xijing Hospital, Air Force Military Medical University from October 2018 to May 2019. Liwen procedure was successfully performed. CT imaging data were collected before operation, and the data were imported into Mimics software for reconstruction. The patients' whole-heart anatomical models were made by 3D printing technology for preoperative imaging evaluation. Ultrasound-guided percutaneous intramyocardial septal radiofrequency ablation was monitored and evaluated by transesophageal echocardiography during the operation. Follow-up observations were carried out at 1, 3, and 6 months after the operation during the first year and every year thereafter. Postoperative evaluation was made by combining imaging and 3D printing techniques. The data including left ventricular ejection fraction, maximum thickness of interventricular septum, and mitral regurgitation before and after operation were compared by paired t test. The data including pressure difference of left ventricular outflow tract and after loading were compared by Wilcoxon signed-rank test.

Liwen procedure was successfully performed in eight patients with obstructive hypertrophic cardiomyopathy. The cardiac function, ventricular septal hypertrophy, and left ventricular outflow tract obstruction were significantly improved after operation. The 3D printing model could accurately reproduce the individual anatomical structure of the patients and assist the preoperative evaluation of Liwen procedure. The intraoperative and postoperative 3D printing models were consistent with the actual operation. Compared with the value before operation, the left ventricular ejection fraction increased significantly at 6 months after operation [(58.36±6.21)% vs (46.25±7.62)%, t=7.998, P=0.015], and the maximum thickness of interventricular septum [(13.92±3.56) mm vs (25.42±4.93) mm, t=14.539, P=0.005] and the mitral regurgitation [(1.04±0.41) ml vs (10.14±3.72) ml, t=4.726, P=0.041] decreased significantly. The pressure difference of left ventricular outflow tract [90.45 (90.00, 110.00) mmHg vs 7.00 (6.00, 10.00) mmHg, Z=2.521, P=0.012] and the pressure difference of left ventricular outflow tract [141.00 (89.25, 150.00) mmHg vs 16.50 (15.00, 17.85) mmHg, Z=2.521, P=0.012] decreased significantly after loading. There were three cases with NYHA class Ⅳ and five cases with NYHA class Ⅲ before operation, while there were six patients with NYHA class I and two patients with NYHA class Ⅱ at 6 months after operation.

3D printing technology is feasible and effective in preoperative evaluation of Liwen procedure for obstructive hypertrophic cardiomyopathy.