Learning Curve of Ex Vivo Liver Resection and Autotransplantation in Treating End-Stage Hepatic Alveolar Echinococcosis: A RA-CUSUM Analysis

Background: This retrospective study aimed to evaluate the safety and learning curve of ex vivo liver resection and autotransplantation (ELRA).Methods: A total of 102 consecutive end-stage HAE patients who underwent ELRA between 2014 and 2020 in West China Hospital were enrolled. The primary endpoint was major postoperative complications (comprehensive complication index, CCI > 26). The ELRA learning curve was evaluated using risk-adjusted cumulative sum (RA-CUSUM) methods. The learning phases were determined based on RA-CUSUM analysis and tested for their association with intra- and post-operative endpoints.Results: The median surgery time was 738 (659–818) min, with a median blood loss of 2,250 (1,600–3,000) ml. The overall incidence of major morbidity was 38.24% (39/102). Risk-adjusted cumulative sum analysis demonstrated a learning curve of 53 ELRAs for major postoperative complications. The learning phase showed a significant association with the hemodynamic unstable time (HR −30.29, 95% CI −43.32, −17.25, P < 0.0001), reimplantation time (HR −13.92, 95% CI −23.17, −4.67, P = 0.004), total postoperative stay (HR −6.87, 95% CI −11.33, −2.41, P = 0.0033), and postoperative major morbidity (HR 0.25, 95% CI 0.09, 0.68, p = 0.007) when adjusted for age, disease course, liver function, and remote metastasis.Discussion:Ex vivo liver resection and autotransplantation is feasible and safe with a learning curve of 53 cases for major postoperative complications.

Learning Curve from 100 Cases of Totally Thoracoscopic Mitral Valve Replacement

Background: To investigate and analyze the learning curve of totally thoracoscopic mitral valve replacement and provide a quantitative reference for cardiac surgeons to carry out the operation step by step. Methods: The clinical data were retrospectively analyzed of 100 consecutive patients with totally thoracoscopic mitral valve replacement successively performed by the same surgeon in a single center from May 2019 to June 2020. The learning curve was divided into 2 stages by using cumulative sum analysis, and relevant surgical parameters and perioperative indicators were analyzed. Results: The first stage of the learning curve is the skill acquisition stage, which includes 1 to 40 surgical procedures. The second stage is the proficiency stage, involving 41 to 100 operations. Among the surgical parameters of the patients in the 2 stages, detectable improvements were observed in operative time, cardiopulmonary bypass time, cross-clamp time, and intraoperative injury. After surgery, the amount of drainage, length of hospital stay, blood creatinine levels, and oxygenation index 24 h after surgery were also significantly different between the 2 groups (all P < .05). The age and sex distributions of the patients were balanced, and there was no statistically significant difference in terms of conversion to median sternotomy between the 2 stages (P > .05). Conclusions: Cumulative sum analysis was used to accurately analyze the learning curve of totally thoracoscopic mitral valve replacement, indicating that 40 cases are needed to master the technique.