Introduction: There is an over-reliance on operative time as a surrogate marker for operative difficulty (OD) for liver resection, which fails to capture the full spectrum the procedure. This study aimed to develop an objective method to assess OD in liver resection and stratify quality outcomes based on OD. Methods: A retrospective review of patients undergoing liver resection for malignant disease between 1999-2023 at a tertiary hospital was completed from a prospectively collected database. Principal component analysis was applied to operative time, estimated blood loss, total time of hepatic inflow occlusion and number of units of blood transfused intraoperatively to derive an OD score using the z-score. Patients were stratified to three groups using Gaussian mixture models (GMM). Textbook oncological outcomes (TOO) and futile resection rates were compared using Chi-squared analysis. Subgroup analysis for overall survival (OS) and disease-free survival (DFS) was completed using the Kaplan-Meier method. Results: Of 729 patients, 699 met the inclusion criteria. GMM identified three distinct OD groups: low (n=540), moderate (n=143), and high (n=16). TOO and non-futile resection rates declined with increasing OD: 77% and 58% (low), 47% and 52% (moderate), and 6% and 19% (high), respectively (p<0.001). Among patients with cholangiocarcinoma, median OS was inversely correlated with OD (40 months low, 16 months moderate, 7 months high, p=0.004). In patients with colorectal liver metastases, there was a trend towards worse OS and DFS with increasing OD, however, this did not reach statistical significance. Conclusion: An objective OD score was developed that showed increasing OD was associated with poorer post-operative outcomes. Integrating the OD score supports more transparent, data-informed surgical decision-making and helps align expectations between teams and patients. Further external prospective studies are required to validate these findings.

Purpose Bile duct brushings (BDB) have low diagnostic sensitivity, negative predictive value and no known prognostic information. We aimed to assess the diagnostic and prognostic performance of BDB and identify clinicopathological factors associated with false-negative BDB. Methodology BDB at Christchurch hospital between January 2018 to March 2024 were retrospectively identified. Patient history, biochemical markers, radiology, management and outcomes were analysed. BDB were categorised according to WHO guidelines. Results Of 418 BDB, 7 (1.7%) were insufficient, 231 (55.3%) benign, 33 (7.9%) atypical, 7 (1.7%) pancreaticobiliary neoplasm, 21 (5.0%) suspicious for malignancy and 119 (28.5%) malignant. Final diagnoses were 156 (37.3%) benign, 157 (37.6%) pancreatic adenocarcinoma, 64 (15.3%) cholangiocarcinoma, 8 (1.9%) ampullary adenocarcinoma, 7 (1.7%) pre-malignant and 26 (6.2%) other malignancies. 140 BDB were true positives, 0 false positives, 117 false-negatives (FN) and 161 true negatives (TN) giving sensitivity 54.5%, specificity 100%, PPV 100% and NPV 57.9%. Compared with TN, FN patients were older (median 73 vs 68 years, p<.001) and more likely to have metabolic disease (59.8% vs 37.7%, p<.001), but less likely to have a history of pancreatitis (8.5% vs 17.0%, p=.030), prior cholangitis (0.9% vs 7.5%, p=.007) or alcohol dependence (0.9% vs 9.4%, p=.003). 42 patients underwent surgery; 6 and 20-month survival rates of 98% and 42% respectively. Comparing those alive at 20 months (20m-A) with those deceased by 20 months (20m-D), bilirubin and CA19-9 did not differ; however, malignant BDB cytology was more frequent in 20m-D (76.5%), whereas benign cytology was more frequent in 20m-A (48.0%) (p=.030). Conclusion BDB has high specificity but limited sensitivity for indeterminate biliary strictures, with false negatives associated with distinct patient factors. WHO BDB cytology categories also appear to stratify survival, suggesting potential prognostic value.

Purpose: Laparoscopic cholecystectomy remains the standard of care for acute cholecystitis; however, a subset of patients is unsuitable for surgery due to frailty, significant comorbidity, hostile anatomy, or advanced malignancy. Endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) using a lumen-apposing metal stent offers a minimally invasive alternative. This study reports clinical outcomes of EUS-GBD and characterises the preoperative factors influencing patient selection. Methodology: A retrospective single-centre audit was performed of all EUS-GBD procedures undertaken between 2020 and 2024 at a tertiary hospital in Melbourne, Australia. All procedures were performed by experienced endoscopists using lumen-apposing metal stents (AXIOS™). Demographic, clinical, and outcome data were collected. Preoperative risk was assessed using the Clinical Frailty Scale (CFS), Charlson Comorbidity Index (CCI), Karnofsky Performance Scale, and the ACS NSQIP surgical risk calculator. Results: Thirty-five patients (median age 75 years) underwent EUS-GBD. Technical success was achieved in 33/35 patients (94%), with clinical symptom resolution in 30/35 (86%). Ninety-day mortality was 26% (n=9); all deaths occurred in patients with metastatic or locally advanced malignancy. Only one patient (3%) required readmission for recurrent acute cholecystitis within 90 days. The majority of patients had active malignancy (20/35). Median CFS was 5 (IQR 4–5), median CCI was 6 (IQR 2–8), and median Karnofsky score was 70 (IQR 55–90). Sixty per cent had a NSQIP-predicted mortality exceeding 10% for laparoscopic cholecystectomy. Patients with higher functional status were selected primarily due to hostile anatomy. Conclusion: EUS-GBD is a safe and effective alternative for high-risk patients with acute cholecystitis, demonstrating high technical and clinical success with low recurrence. Current surgical risk tools broadly align with clinician judgement in patient selection; however, prospective trial data is required to help develop a dedicated framework.