Robotic major and minor hepatectomy: critical appraisal of learning curve and its impact on outcomes.

BACKGROUND: Robotic hepatectomy has gained increasing acceptance across the US. Although the robotic approach offers significant technical advantages, it is still bound by the individual surgeon's learning curve. Proficiency in this approach should theoretically lead to improved peri-operative outcomes. METHODS: Between 2017 and 2020, data on 148 consecutive robotic hepatectomies performed by a single surgeon was retrospectively analyzed. Using cumulative sum (CUSUM) method, intraoperative blood loss (EBL) and operative time were used to assess learning curves for robotic major (n = 58) and minor (n = 90) hepatectomy patients. Perioperative outcomes were compared in regards with proficiency. RESULTS: Proficiency for robotic major and minor hepatectomy was achieved after 22 cases and 34 cases, respectively. No significant differences were observed in patient demographics or tumor characteristics. For robotic major hepatectomy, when compared to early experience, proficiency was associated with a significant improvement in mean EBL (242 mL vs 118 mL, p = 0.0004), operative time (330 min vs 247 min, p = 0.0002), decreased overall complication rate (23% vs 3%, p = 0.039), and length of hospital stay (5.7 days vs 4.1 days, p = 0.004). No difference in conversion rate, mortality or 30 day readmission was seen. For robotic minor hepatectomy, proficiency was associated with significantly decreased mean EBL (115 mL vs 54 mL, p = 0.005), operative time (168 vs 125 min, p = 0.014), and length of hospital stay (2.8 days vs 2.1 days, p = 0.021). No difference was observed in conversion rate, overall complications, mortality or 30 day readmission. CONCLUSION: In the modern era, robotic hepatectomy offers a safe approach with excellent perioperative outcomes. Post learning curve proficiency is associated with significant improvements in perioperative outcomes in both major and minor hepatectomy. Results from our study can serve as a guide to surgeons and programs looking to adopt this technique.

Effects of oral N-acetylcysteine on fatigue, critical power, and W' in exercising humans.

The accumulation of reactive oxygen species (ROS) is associated with muscular fatigue. The antioxidant N-acetylcysteine (NAC) can extend time to fatigue (TTF), but the effect appears to be exercise intensity dependent. The purpose of this study was to determine the effects of an acute oral dose of NAC on time to fatigue (TTF), critical power (CP), W' (curvature constant), V(O2) kinetics and muscle EMG during cycling exercise. Male (n=7) subjects performed four tests at power outputs corresponding to 80, 90, 100, and 110% of the peak power output achieved during the incremental test (Pmax) under NAC and placebo (PLA) conditions. TTF was increased only in the 80% Pmax trial (p=0.033). CP was higher with NAC (NAC: 232±28 W versus PLA: 226±31 W; p=0.032), but W' tended to decrease (NAC: 15.5±3.8 kJ versus W': 16.4±4.5 kJ; p=0.10). The change in W' was negatively related to the change in CP (r = -0.96). MdPF and RMS of EMG tended to change less with NAC. There were no significant differences in V(O2) kinetics. These results demonstrate that oral NAC was successful in extending time to fatigue at 80% Pmax but not at higher work rates.