Statistical analysis
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SECONDARY
Given the exploratory nature of this pilot clinical trial and the absence of previous studies comparing MGVA with the conventional conservative treatment, we did not perform a formal sample size calculation. Therefore, we set a target of 20 patients as a reasonable and affordable goal for this pilot study.All gathered data was summarized by study groups using appropriate statistical methods according to their type. Continuous variables were presented with mean and standard deviation, except for those with asymmetry or lack of normality which were described with median and interquartile range. Categorical variables were reported as the number of cases and the percentage of the total. The demographic and clinical profiles of the included patients were described in total, and by study group. The secondary endpoints were analyzed following the same procedure described below for the QoL. The evolution of the average QoL throughout the 6 months period was described with graphs and descriptive statistics. QoL improvement between the study groups was calculated through a covariance analysis, considering QoL at 2 months (measured by the SF-36 questionnaire) as the dependent variable as well as the study group and QoL at the baseline visit (also measured by the SF-36 questionnaire) as independent variables. Improvement was quantified by estimating the expected marginal effect on QoL at 2 months by study group.A 95% confidence interval (95% CI) for the estimations was provided whenever possible. The statistical analyses were performed with the R program version 4.1.2 for Windows® (R Foundation for Statistical Computing).No interim analysis and no subgroup or adjusted analyses were performed. Also, this study did not have a Data Safety and Monitoring Committee; monitoring was conducted by study team members not involved in patient inclusion and follow-up.