A secondary learning curve in 3D versus 2D imaging in laparoscopic training of surgical novices.

BACKGROUND: Stereoscopic (3D) imaging can be used to facilitate the learning of basic laparoscopic tasks. Its advantages over traditional endoscopic (2D) imaging include better depth perception and spatial orientation. However, the transition between 3D and 2D imaging systems has not been previously studied. This study compares the acquisition of basic laparoscopic skills in a laparoscopic-naïve population using both imaging systems, and explores the possibility of a secondary learning curve in the transition between systems. METHODS: 26 novice learners were randomly allocated into two arms and taught to perform two basic laparoscopic tasks adopted from the fundamentals of laparoscopic surgery (FLS) curriculum, peg transfer (T1) and pattern cutting (T2) using either 2D or 3D imaging systems. These tasks were repeated until proficiency was achieved. Participants in each arm then repeated the tasks in the other viewing system (2D/3D vs 3D/2D). The parameters measured were: (a) time taken to complete the task and (b) number of attempts to achieve proficiency. RESULTS: There was a significant shortening of time required to achieve proficiency in T2 using a 3D system (mean difference-in-differences = - 65.4, 95% CI - 103.6 to - 27.2, t(24) = - 3.5, p value = 0.002) but no difference between 2D and 3D imaging systems for T1, a simpler task. Sub-group analysis of T1 and T2 between the 2D/3D and 3D/2D arms showed the presence of a secondary learning curve in the 2D/3D arm for both tasks, (T1: ß-estimate - 2.68, 95% CI - 3.68 to - 1.68, p value = 0.0003; T2: ß-estimate - 2.45, 95% CI - 3.75 to - 1.14, p value 0.004), but in the 3D/2D arm there was a secondary learning curve only for T2. (ß-estimate 2.60, 95% CI 1.45-3.76, p value 0.001) CONCLUSION: 3D imaging can be an effective tool to speed the acquisition of proficiency in basic laparoscopic tasks for novice learners, especially in more complex tasks such as pattern cutting. The skills learned in 3D imaging can translate into 2D, albeit with a secondary learning curve.

Predictors of post-operative complications after surgical resection of hepatocellular carcinoma and their prognostic effects on outcome and survival: A propensity-score matched and structural equation modelling study.

INTRODUCTION: Although hepatectomy is the mainstay of curative therapy for hepatocellular carcinoma (HCC), post-operative complications remain high. Presently there is conflicting data on the impact of morbidity on oncologic outcomes. We sought to identify predictors for the occurrence of post-hepatectomy complications, as well as to analyse the impact on overall survival (OS) and recurrence-free survival (RFS). MATERIALS AND METHODS: We performed a retrospective review of 888 patients who underwent resection for HCC from 2001 to 2016 in our institution. RESULTS: A total of 237 patients (26.7%) developed 254 complications of Clavien-Dindo Grade ≥2. Hepatitis B (p = 0.0397), elevated ASA score (p = 0.0002), higher platelet counts (p = 0.0277), raised pre-operative APRI scores (p = 0.0105) and bloodloss (p < 0.0001) were independently associated with the development of complications. After propensity-score matching, 458 patients were compared in a 1:1 ratio (229 with complications versus 229 without). Patients with complications had significantly longer median length of stay (9 days [IQR 7-15] versus 6 days [IQR 5-8], p < 0.0001), higher 90-day mortality rates as well as inferior OS (p = 0.0139), but there was no difference in RFS (p = 0.4577). Age (p = 0.0006), elevated Child Pugh points (p < 0.0001), microvascular invasion (p = 0.0002), multifocal tumours (p = 0.0002), R1 resection (p = 0.0443) and development of complications (p = 0.0091) were independent predictors of inferior OS. CONCLUSION: Post-operative morbidity affected both short-term and OS outcomes after hepatectomy for HCC. Hepatitis B, higher ASA scores, elevated preoperative APRI and increased blood loss were found to predict a higher likelihood of developing complications. This may potentially be mitigated by careful patient selection and adopting strict measures to minimise intraoperative bleeding.