Abstract
BackgroundTo examine residual defects(RS) and examined the rate of spontaneous RS closure over time to identify factors associated with the occurrence and spontaneous closure of these defects after two different operation methods.MethodsIn this retrospective analysis, we enrolled only patients with perimembranous VSDs (pmVSDs) and reviewed the clinical records of patients who underwent repair for pmVSDs between January 2016 and January 2019. All patients underwent surgery with either cardiopulmonary bypass (the CPB group) or minimally invasive closure of transthoracic VSDs under the guidance of TEE (the MIC group). There were 189 patients who underwent CPB surgery and 211 patients who underwent MIC surgery. Ultimately, there were 37 patients with RSs in the CPB group (surgical repair via CPB) and 39 patients with RSs in the MIC group (minimally invasive closure of transthoracic VSDs). Postoperatively, all surgical patients were required to return for outpatient follow-up visits, and echocardiography was required to evaluate the RS. Assessments included shunt velocity and RS size.ResultsIn the CPB group, 16 patients had a small RS, and 21 patients had a moderate RS. The comparison between the variables such as weight, preoperative VSD size, and RS size revealed no significant differences except RS size (P=0.000). To compare the spontaneous closure rates of the two sizes of RSs(the moderate group and small size group), Kaplan-Meier plots were used. These plots show that the small size was more likely to undergo spontaneous closure (P=0.034), but the final spontaneous closure rate was not significantly different (P=1.000).In the MIC group, there were 29 patients in the small group and 10 patients in the moderate group, and the variables such as weight, preoperative VSD size, and preoperative VSD size showed no significant differences except RS size and the rate of no spontaneous closure (P=0.000 vs. 0.045). The Kaplan-Meier plots (Figure 2) showed that the small size was RSs were more likely to undergo spontaneous closure (P=0.004), while the final spontaneous closure rate was significantly different between groups (P=0.045).At 2 years post-operation, 7 patients still had RSs, and the overall spontaneous closure rate was 90.8%. The size of the RS on discharge was the only variable identified, on Cox regression, to be predictive of the likelihood of spontaneous closure. The univariate analysis, however, showed that shunt velocity had no association with spontaneous closure. Factors including age, weight, sex, surgical technique, and VSD size had no association with spontaneous closure.ConclusionThe RS incidence and spontaneous closure rates were not significantly different two different operation methods. Small RSs were more likely to undergo spontaneous closure in both groups.