IWATE criteria are associated with perioperative outcomes in robotic hepatectomy: a retrospective review of 225 resections.

BACKGROUND: Robotic hepatectomy (RH) is increasingly utilized for minor and major liver resections. The IWATE criteria were developed to classify minimally invasive liver resections by difficulty. The objective of this study was to apply the IWATE criteria in RH and to describe perioperative and oncologic outcomes of RH over the last decade at our institution. METHODS: Perioperative and oncologic outcomes of patients who underwent RH between 2011 and 2019 were retrospectively collected. The difficulty level of each operation was assessed using the IWATE criteria, and outcomes were compared at each level. Univariate linear regression was performed to characterize the relationship between IWATE criteria and perioperative outcomes (OR time, EBL, and LOS), and a multivariable model was also developed to address potential confounding by patient characteristics (age, sex, BMI, prior abdominal surgery, ASA class, and simultaneous non-hepatectomy operation). RESULTS: Two hundred and twenty-five RH were performed. Median IWATE criteria for RH were 6 (IQR 5-9), with low, intermediate, advanced, and expert resections accounting for 23% (n = 51), 34% (n = 77), 32% (n = 72), and 11% (n = 25) of resections, respectively. The majority of resections were parenchymal-sparing approaches, including anatomic segmentectomies and non-anatomic partial resections. 30-day complication rate was 14%, conversion to open surgery occurred in 9 patients (4%), and there were no deaths within 30 days postoperatively. In the univariate linear regression analysis, IWATE criteria were positively associated with OR time, EBL, and LOS. In the multivariable model, IWATE criteria were independently associated with greater OR time, EBL, and LOS. Two-year overall survival for hepatocellular carcinoma and intrahepatic cholangiocarcinoma was 94% and 50%, respectively. CONCLUSION: In conclusion, the IWATE criteria are associated with surgical outcomes after RH. This series highlights the utility of RH for difficult hepatic resections, particularly parenchymal-sparing resections in the posterosuperior sector, extending the indication of minimally invasive hepatectomy in experienced hands and potentially offering select patients an alternative to open hepatectomy or other less definitive liver-directed treatment options.

Quality of superior mesenteric and hepatic artery dissection in robotic pancreatoduodenectomy for pancreatic cancer.

This video manuscript by Ikoma and colleagues demonstrates their approach to the superior mesenteric artery and hepatic artery periadventitial dissection. The quality of superior mesenteric artery and hepatic artery dissections should be maintained in robotic pancreatoduodenectomy when performed for pancreatic cancer, to provide the best possible oncological outcomes.

Tumor slice culture as a biologic surrogate of human cancer.

BACKGROUND: The tumor microenvironment (TME) is critical to every aspect of cancer biology. Organotypic tumor slice cultures (TSCs) preserve the original TME and have demonstrated utility in predicting drug sensitivity, but the association between clinicopathologic parameters and in vitro TSC behavior has not been well-defined. METHODS: One hundred and eight fresh tumor specimens from liver resections at a tertiary academic center were procured and precisely cut with a Vibratome to create 250 µm × 6 mm slices. These fixed-dimension TSCs were grown on polytetrafluoroethylene inserts, and their metabolic activities were determined by a colorimetric assay. Correlation between baseline activities and clinicopathologic parameters was assessed. Tissue CEA mRNA expression was determined by RNAseq. RESULTS: By standardizing the dimensions of a slice, we found that adjacent tumor slices have equivalent metabolic activities, while those derived from different tumors exhibit >30-fold range in baseline MTS absorbances, which correlated significantly with the percentage of tumor necrosis based on histologic assessment. Extending this to individual cancers, we were able to detect intra-tumoral heterogeneity over a span of a few millimeters, which reflects differences in tumor cell density and Ki-67 positivity. For colorectal cancers, tissue CEA expression based on RNAseq of tumor slices was found to correlate with clinical response to chemotherapies. CONCLUSIONS: We report a standardized method to assess and compare human cancer growth ex vivo across a wide spectrum of tumor samples. TSC reflects the state of tumor behavior and heterogeneity, thus providing a simple approach to study of human cancers with an intact TME.

Enhanced Recovery via Peripheral Nerve Block for Open Hepatectomy.

BACKGROUND: Enhanced recovery after surgery (ERAS) protocols are now commonplace in many fields of surgery, but only limited data exists for their use in hepatobiliary surgery. We implemented standardized ERAS protocols for all open hepatectomies and replaced thoracic epidurals with a transversus abdominis plane (TAP) block. METHODS: We performed a retrospective cohort study of all patients undergoing open hepatectomy during the 14 months before and 19 months after implementation of an ERAS protocol at our institution (January 2014-September 2016). Trained abstractors reviewed charts for patient demographics, perioperative details, and healthcare utilization. All nursing-reported visual analog scale pain scores were sampled to identify patients with uncontrolled pain (daily mean score > 5). Outcomes included length of stay (LOS), costs, and 30-day readmission. RESULTS: A total of 127 patients (mean age 54.6 ± 13.0 years, 44% female) underwent open liver resection (69 [54%] after ERAS implementation). ERAS protocols were associated with significantly lower rates of ICU admission (47 vs. 13%, p < 0.001), shorter LOS (median 5.3 vs. 4.3 days, p = 0.007), and lower median costs ($3566 less, p = 0.03). Readmission remained low throughout the study period (5% pre-ERAS, 4% during ERAS, p = 0.83). Rates of uncontrolled pain were either the same or better after ERAS implementation through post-operative day #3 (41% pre-ERAS, 23% during ERAS, p = 0.03). DISCUSSION: The use of TAP block for hepatectomy as part of an ERAS protocol is associated with improved quality and cost of care. Surgeons performing liver resections should consider standardization of evidence-based best practices in all patients.