The final limitation
of our study was the relatively high withdrawal rate
(23.4%). Although all patients agreed to the study schedule
before enrollment, unavoidable scheduling conflicts
arose. The most common cause was noncompliance with
follow-up owing to a long distance from the center to the
home or personal circumstances. It was inevitable, because
patients could stop their participation in the study
at any point. However, we could ensure that they did not
differ significantly in terms of the preoperative and intraoperative
factors.