Groot Koerkamp, Bas

Abstract Background Some centres advocate preoperative radiotherapy in patients with pancreatic cancer and arterial involvement despite a lack of Level 1 evidence on survival benefit. Although it has been suggested that preoperative radiotherapy may increase the risk of postpancreatectomy haemorrhage (PPH) and morbidity, evidence is again lacking. This study investigated the association between preoperative radiotherapy and both PPH and major morbidity following arterial divestment/resection during pancreatic adenocarcinoma resection after chemotherapy. Methods Consecutive patients diagnosed with pancreatic adenocarcinoma and > 180° arterial involvement who were treated with preoperative chemotherapy with or without radiotherapy followed by pancreatic resection with arterial divestment/resection were included in the study. Logistic regression analyses including propensity score-based overlap weighting were performed to investigate associations between radiotherapy and in-hospital PPH grade B/C and major morbidity, expressed as adjusted risk differences (aRDs). Results Overall, 246 patients undergoing pancreatic resection with arterial resection (169, 69%) or divestment (77, 31%) were included. Radiotherapy was not associated with PPH (aRD 6%; 95% confidence interval (c.i.) −3 to 14), regardless of arterial divestment (aRD 3%; 95% c.i. −5 to 11) or arterial resection (aRD 12%; 95% c.i. 1 to 23; Pinteraction = 0.189). Radiotherapy was associated with a 14% (95% c.i. 2 to 25) higher risk of major morbidity, especially after arterial resection (aRD 27%; 95% c.i. 11 to 43) compared with arterial divestment (aRD −12%; 95% c.i. −35 to 11; Pinteraction = 0.006) and after external beam radiotherapy (aRD 21%; 95% c.i. 8 to 32) compared with stereotactic body radiotherapy (aRD −12%; 95% c.i. −27 to 6; Pinteraction = 0.0001). Ninety-day mortality was increased, albeit not significantly, after preoperative radiotherapy (10 (8%) versus 3 (3%) deaths with versus without preoperative radiotherapy, respectively; P = 0.067). Conclusions Radiotherapy before resection of pancreatic cancer with > 180° arterial involvement was associated with an increased risk of postoperative major morbidity when arterial resection, but not arterial divestment, was performed. This risk should be taken into account when considering preoperative radiotherapy in patients who may require arterial resection.

Abstract Background The increased use of superior mesenteric artery (SMA) divestment has been a driver behind the increased resection rate for locally advanced pancreatic cancer following preoperative therapy. This has also resulted in an increase in the rate of postoperative neurogenic diarrhoea, but knowledge about postoperative neurogenic diarrhoea is lacking. The aims of this study were to determine the incidence, risk factors, management, and outcomes of neurogenic diarrhoea after SMA divestment/resection for pancreatic adenocarcinoma. Methods This multicentre retrospective study included consecutive patients undergoing pancreatic adenocarcinoma resection, including SMA divestment/resection, after preoperative chemotherapy with or without radiotherapy between 2016 and 2022. Primary endpoints were the incidence of postoperative neurogenic diarrhoea, associated factors, treatment strategies, and outcomes. Secondary endpoints were the rate of adjuvant chemotherapy and the impact of neurogenic diarrhoea on overall survival (OS). Results Overall, 291 patients who underwent pancreatic resection with concomitant SMA divestment (240, 82%) or resection (51, 18%) were included in the study. Postoperative neurogenic diarrhoea was diagnosed in 193 patients. The adjusted risk of developing neurogenic diarrhoea was 59% (95% confidence interval (c.i.) 46 to 73) after ≤ 180° SMA divestment, 80% (95% c.i. 67 to 93) after > 180° SMA divestment, and 77% (95% c.i. 66 to 88) after SMA resection. Postoperative neurogenic diarrhoea was treated with non-opioid drugs (29, 15%), non-opium opioids (140, 73%), opium tincture (69, 36%), and/or octreotide (49, 25%), and normalized in 51% of patients. After adjusting for confounders, neurogenic diarrhoea was not significantly associated with OS (hazard ratio 0.83; 95% c.i. 0.55 to 1.25). Conclusion Neurogenic diarrhoea occurred in two-thirds of patients following resection of pancreatic adenocarcinoma with concomitant SMA divestment/resection, particularly after > 180° SMA divestment or SMA resection. Although challenging to manage, neurogenic diarrhoea is not associated with impaired OS. Evidence-based treatment strategies are needed for adequate management.

Importance Total pancreatectomy (TP) is indicated for advanced pancreatic cancer or multifocal tumors. Furthermore, TP may be performed to avoid the risk of pancreatic fistula in selected patients to improve the perioperative risk profile. Objective To define reference values for TP based on a low-risk cohort treated at expert centers. Design, Setting, and Participants This multicenter study analyzed outcomes from patients undergoing primary TP for malignant or benign lesions from 25 international expert centers from January 2017 to November 2023. Low-risk patients undergoing TP (LR-TP) were without vascular resections or significant comorbidities. Exposures TP. Main Outcomes and Measures Twenty reference values were derived from the 75th or the 25th percentile of the median values of all centers. Outcomes of LR-TP were compared with a cohort of TP with vascular resection, TP due to high-risk pancreatic anastomosis, and the benchmark values for low-risk pancreatoduodenectomy. Results Of 994 patients, 333 (33.5%; median [IQR] age, 66 [58-72] years; 171 male [51.4%]) qualified as the LR-TP cohort. Reference values included blood loss (≤1000 mL), major complications (≤37%), 3-month postoperative mortality (<6%), and retrieved lymph nodes (≥29). Compared with TP with vascular resections, reference cutoffs were not met for major complications (51% vs LR-TP ≤37%) and 90-day mortality (11% vs LR-TP ≤6%). For TP due to high-risk anastomosis, failure to rescue rate (38% vs ≤6%) and 90-day mortality (11% vs LR-TP ≤6%) were not met. Compared with pancreatoduodenectomy, reference values for postoperative mortality were 3 times higher for LR-TP (≤2% vs ≤6%) and less for resected lymph nodes (≥16 vs ≥29). Conclusions and Relevance This case-control study provided global reference values for TP, indicating significantly higher postoperative morbidity and mortality compared with pancreatoduodenectomy. Perioperative morbidity of TP was especially increased in patients with vascular resections. These reference values can serve for quality control of pancreatic surgery.

Objective: To determine the prevalence of clinical significance reporting in contemporary comparative effectiveness research (CER). Background: In CER, a statistically significant difference between study groups may or may not be clinically significant. Misinterpreting statistically significant results could lead to inappropriate recommendations that increase health care costs and treatment toxicity. Methods: CER studies from 2022 issues of the Annals of Surgery , Journal of the American Medical Association , Journal of Clinical Oncology , Journal of Surgical Research , and Journal of the American College of Surgeons were systematically reviewed by 2 different investigators. The primary outcome of interest was whether the authors specified what they considered to be a clinically significant difference in the “Methods.” Results: Of 307 reviewed studies, 162 were clinical trials and 145 were observational studies. Authors specified what they considered to be a clinically significant difference in 26 studies (8.5%). Clinical significance was defined using clinically validated standards in 25 studies and subjectively in 1 study. Seven studies (2.3%) recommended a change in clinical decision-making, all with primary outcomes achieving statistical significance. Five (71.4%) of these studies did not have clinical significance defined in their methods. In randomized controlled trials with statistically significant results, sample size was inversely correlated with effect size ( r = −0.30, P = 0.038). Conclusions: In contemporary CER, most authors do not specify what they consider to be a clinically significant difference in study outcome. Most studies recommending a change in clinical decision-making did so based on statistical significance alone, and clinical significance was usually defined with clinically validated standards.

Objective: The aim of this study was to define robust benchmark values for the surgical treatment of perihilar cholangiocarcinomas (PHC) to enable unbiased comparisons. Background: Despite ongoing efforts, postoperative mortality and morbidity remains high after complex liver surgery for PHC. Benchmark data of best achievable results in surgical PHC treatment are however still lacking. Methods: This study analyzed consecutive patients undergoing major liver surgery for PHC in 24 high-volume centers in 3 continents over the recent 5-year period (2014–2018) with a minimum follow-up of 1 year in each patient. Benchmark patients were those operated at high-volume centers (≥50 cases during the study period) without the need for vascular reconstruction due to tumor invasion, or the presence of significant co-morbidities such as severe obesity (body mass index ≥35), diabetes, or cardiovascular diseases. Benchmark cutoff values were derived from the 75th or 25th percentile of the median values of all benchmark centers. Results: Seven hundred eight (39%) of a total of 1829 consecutive patients qualified as benchmark cases. Benchmark cut-offs included: R0 resection ≥57%, postoperative liver failure (International Study Group of Liver Surgery): ≤35%; in-hospital and 3-month mortality rates ≤8% and ≤13%, respectively; 3-month grade 3 complications and the CCI: ≤70% and ≤30.5, respectively; bile leak-rate: ≤47% and 5-year overall survival of ≥39.7%. Centers operating mostly on complex cases disclosed better outcome including lower post-operative liver failure rates (4% vs 13%; P = 0.002). Centers from Asia disclosed better outcomes. Conclusion: Surgery for PHC remains associated with high morbidity and mortality with now the availability of benchmark values covering 21 outcome parameters, which may serve as key references for comparison in any future analyses of individuals, group of patients or centers.