Must Clinics Replace 2D by 3D Environments for an Efficient Training of Laparoscopic Novices? A Critical Analysis of the Learning Curve for Basic Skills.

BACKGROUND AND AIMS: Published studies repeatedly demonstrate an advantage of three-dimensional (3D) laparoscopic surgery over two-dimensional (2D) systems but with quite heterogeneous results. This raises the question whether clinics must replace 2D technologies to ensure effective training of future surgeons. METHODS: We recruited 45 students with no experience in laparoscopic surgery and comparable characteristics in terms of vision and frequency of video game usage. The students were randomly allocated to 3D (n = 23) or 2D (n = 22) groups and performed 10 runs of a laparoscopic "peg transfer" task in the Luebeck Toolbox. A repeated-measures ANOVA for operation times and a generalized linear mixed model for error rates were calculated. The main effects of laparoscopic condition and run, as well as the interaction term between the two, were examined. RESULTS: No statistically significant differences in operation times and error rates were observed between 2D and 3D groups (p = 0.10 and p = 0.72, respectively). The learning curve showed a significant reduction in operation time and error rates (both p's < 0.001). No significant interactions between group and run were detected (operation time: p = 0.342, error rates: p = 0.83). With respect to both endpoints studied, the learning curves reached their plateau at the 7th run. CONCLUSION: The result of our study with laparoscopic novices revealed no significant difference between 2D and 3D technology with respect to performance time and the error rate in a simple standardized test. In the future, surgeons may thus still be trained in both techniques.

Hospital volume and mortality in liver resections for colorectal metastasis using population-based administrative data.

BACKGROUND: Approximately one-quarter of patients with colorectal carcinoma develop colorectal liver metastases (CRLM). Surgical treatment with curative intent by hepatic resection is the standard medical care. While some studies with small sample sizes have investigated the relationship between hospital procedure volume and in-hospital mortality for this diagnosis, no population-based study has been conducted. The present study was aimed at closing this gap. METHODS: Based on administrative population-based hospital discharge data (Diagnosis Related Group Statistic), patients diagnosed with CRLM and treated with hepatic resection from 2011 to 2015 were identified. The hospital operation-volume effect on risk-adjusted in-hospital mortality was examined by logistic regression models. RESULTS: During the study period, 5900 patients with CRLM were treated with hepatic resection, of whom 189 (3.2%) died before hospital discharge. Hospitals of different operation-volume quartiles did not differ in terms of mortality rates. Sensitivity analysis investigating the volume-mortality relationship separately for every resection procedure showed no clear result. Procedure frequencies vary among hospitals of different volume quartiles, with low-volume hospitals performing systematically more low-risk procedures (in terms of reduced mortality rate), than high-volume hospitals. CONCLUSION: Based on almost complete German hospital discharge data, the results did not confirm unconditional volume-outcome relationship for CRLM patients.