Background: Clinically relevant postoperative pancreatic fistula (CR-POPF) remains a leading cause of morbidity after laparoscopic distal pancreatectomy (LDP), with rates plateauing at 20%–30%. Staple-line clip reinforcement is a widely used technical adjunct intended to reduce CR-POPF, but multicenter randomized evidence supporting its routine use is lacking. This study aimed to evaluate whether routine clip reinforcement reduces CR-POPF incidence and whether its effect is influenced by pancreatic texture or friability. Materials and methods: This multicenter, open-label, randomized clinical trial was conducted at three tertiary referral centers in the Republic of Korea between June 2021 and February 2025. A total of 190 adult patients undergoing elective LDP were randomized 1:1 to stapled transection with metallic clip reinforcement (clip group, n = 96) or standard stapled transection alone (no-clip group, n = 94). The primary outcome was CR-POPF incidence (ISGPS grade B or C). Prespecified subgroup analyses assessed treatment-by-subgroup interactions according to pancreatic texture, friability, body mass index, and operation time. Results: In the intention-to-treat analysis, CR-POPF occurred in 21 of 96 patients (21.9%) in the clip group and 26 of 94 patients (27.7%) in the no-clip group [risk difference, −5.8% (95% CI, −17.5%–6.0%); P = 0.45]. No grade C fistulas occurred. Per-protocol analysis yielded consistent results. No significant treatment effect modification was observed in any prespecified subgroup. Multivariable analysis identified prolonged operation time as the only independent risk factor for CR-POPF [adjusted OR, 1.012 per minute (95% CI, 1.004–1.020); P = 0.004]. Conclusion: Routine staple-line clip reinforcement during LDP did not significantly reduce CR-POPF incidence. These findings do not support its routine use in an unselected LDP population and suggest that operative efficiency may be a more relevant target for CR-POPF prevention than additional technical reinforcement.

BACKGROUND:Inverse probability weighting (IPW) is a widely used method to estimate the causal effect of treatment from observational data. However, it can be unstable when extreme propensity score (PS) values lead to very large weights. Overlap weights (OW), which emphasize subjects in areas of covariate overlap, reduce the influence of extreme PS without excluding participants. While the OW method has shown strong performance in simulations with continuous outcomes, its utility in binary outcome settings-common in health research-has not been thoroughly evaluated. METHODS:We conducted simulation studies to evaluate the performance of OW in comparison to other PS weighting methods including IPW, trimmed IPW, and matching weights, in settings with extreme PS values and a binary outcome. Using simulated datasets with varying degrees of PS overlap and treatment prevalence, we assessed covariate balance and treatment effect estimation performance. The performance of the PS weighting methods was further illustrated through an application to data from a study on pancreatic ductal adenocarcinoma. RESULTS:In simulation studies, IPW's performance deteriorated markedly as the overlap in the covariate distribution decreased. In contrast, OW achieved exact covariate balance and consistently showed the highest efficiency among all methods evaluated. In the application to real-world data characterized by low treatment prevalence and substantial covariate imbalance, OW also outperformed the other methods in terms of both standard error and covariate balance. CONCLUSION:These findings suggest superior performance of OW in terms of covariate balance and estimation efficiency in settings with extreme PS and a binary outcome.

(1) Background: The aim of this study was to compare the survival benefit of radical antegrade modular pancreatosplenectomy (RAMPS) with conventional distal pancreatosplenectomy (cDPS) in left-sided pancreatic cancer. (2) Methods: A retrospective propensity score matching (PSM) analysis was conducted on 333 patients who underwent RAMPS or cDPS for left-sided pancreatic cancer at four tertiary cancer centers. The study assessed prognostic factors and compared survival and operative outcomes. (3) Results: After PSM, 99 patients were matched in each group. RAMPS resulted in a higher retrieved lymph node count than cDPS (15.0 vs. 10.0, p < 0.001). No significant differences were observed between the two groups in terms of R0 resection rate, blood loss, hospital stay, or morbidity. The 5-year overall survival rate was similar in both groups (cDPS vs. RAMPS, 44.4% vs. 45.2%, p = 0.853), and disease-free survival was also comparable. Multivariate analysis revealed that ASA score, preoperative CA19-9, histologic differentiation, R1 resection, adjuvant treatment, and lymphovascular invasion were significant prognostic factors for overall survival. Preoperative CA19-9, histologic differentiation, T-stage, adjuvant treatment, and lymphovascular invasion were independent significant prognostic factors for disease-free survival. (4) Conclusions: Although RAMPS resulted in a higher retrieved lymph node count, survival outcomes were not different between the two groups. RAMPS was a surgical option to achieve R0 resection rather than a standard procedure.

Background: The aim of this study is to investigate the perioperative composite textbook outcomes of pancreatic surgery after minimally invasive pancreatoduodenectomy (MIPD). Materials and methods: The cohort study was conducted across 10 institutions and included 1552 patients who underwent MIPD registered with the Korean Study Group on Minimally Invasive Pancreatic Surgery between May 2007 and April 2020. We analyzed perioperative textbook outcomes of pancreatic surgery after MIPD. Subgroup analyses were performed to assess outcomes based on the hospital volume of MIPD. Results: Among all patients, 21.8% underwent robotic pancreatoduodenectomy. High-volume centers (performing >20 MIPD/year) performed 88.1% of the procedures. The incidence of clinically relevant postoperative pancreatic fistula was 11.5%. Severe complications (Clavien–Dindo grade ≥IIIa) occurred in 15.1% of the cases. The 90-day mortality rate was 0.8%. The mean hospital stay was 13.7 days. Textbook outcomes of pancreatic surgery success were achieved in 60.4% of patients, with higher rates observed in high-volume centers than in low-volume centers (62.2% vs. 44.7%, P<0.001). High-volume centers exhibited significantly lower conversion rates (5.4% vs. 12.5%, P=0.001), lower 90-day mortality (0.5% vs. 2.7%, P=0.001), and lower 90-day readmission rates (4.5% vs. 9.6%, P=0.006) than those low-volume centers. Conclusion: MIPD could be performed safely with permissible perioperative outcomes, including textbook outcomes of pancreatic surgery, particularly in experienced centers. The findings of this study provided valuable insights for guiding surgical treatment decisions in periampullary disease.

675 Background: The association of resection margin status with recurrence and survival after pancreatectomy for pancreas ductal adenocarcinoma (PDAC) remains controversial. The aim of this study was to identify the effect of R1 resection on recurrence pattern and survival after distal pancreatectomy for left-sided PDAC. Methods: Patients who underwent distal pancreatectomy for PDAC at two high-volume institutions between January 2010 and December 2017 were retrospectively reviewed. Perioperative characteristics, pathological outcomes, recurrence pattern and survival data were collected to compare R0 resection and R1 resection. Results: Among 558 patients who underwent distal pancreatectomy for PDAC, 158 patients (28.3%) showed R1 resection margin. R1 patients were associated with large tumor size (3.3 cm vs. 3.7 cm, p= 0.006) and lower number of positive lymph nodes (1.3 vs. 2.0, p= 0.001). Median overall survival (37.3 months vs. 20.1 months, p< 0.001) and recurrence-free survival (14.6 months vs. 6.9 months, p< 0.001) significantly differed between the R0 and R1 groups. Disease recurrence patterns were not statistically different between the two groups ( p = 0.182). Among the recurrence patterns, peritoneal carcinomatosis had the shortest recurrence-free survival (5.6 months, p < 0.05) and overall survival (13.6 months, p < 0.05) compared with all other recurrence patterns. Conclusions: R1 resection margin after distal pancreatectomy was associated with poor survival and early recurrence. There is no significant difference in recurrence pattern between R0 and R1. Among the recurrence patterns, peritoneal carcinomatosis showed the worst prognosis.

Background: Hospital volume remains controversial on postoperative outcome after minimally invasive pancreatoduodenectomy (MIPD).A few studies report that an objective hospital volume threshold is associated with safety of MIPD.The aim of this study is to identify whether there is a difference in postoperative outcomes in high-volume and low-volume center by single surgeon's operation.Methods: The patients undergoing MIPD at a high volume center (Asan Medical Center) and at a low volume center (Kangbuk Samsung hospital) from July 2018 and December 2022 were retrospectively reviewed.After operating on 56 cases at high volume center, 30 cases were performed at low volume center by single surgeon.Demographics, perioperative and pathologic outcomes were compared between the two groups.Results: Even though patients of high volume center had better surgical conditions than low volume center due to lower BMI (23.1 kg/m 2 vs. 25.0 kg/m 2 , p = 0.012), ASA scores (p < 0.001), and large pancreas duct size (3.3 mm vs. 2.2 mm, p < 0.001), there were no statistical differences in operation time (356 min vs. 370 min, p = 0.340) and open conversion rate (1.8% vs. 0.0%, p = 0.651).In addition, there were no differences in Clavien Dindo grade 3 or higher complication rate (7.1% vs. 6.7%, p > 0.999), post-operative pancreatic fistula (10.7% vs. 6.7%, p = 0.708) , delayed gastric emptying (0.0% vs. 3.3%, p = 0.349), post pancreatectomy hemorrhage (5.4% vs. 3.3%, p > 0.999), 90-day mortality (0.0% vs. 0.0%, p > 0.999) and hospital stay after operation (10.27 days vs. 10.73 days, p = 0.649) between high and low volume center.The proportion of malignancy was also not significantly different between two groups (66.1% vs. 60.0%,p = 0.576).Conclusions: This study suggests that MIPD can also be performed feasibly and safely by a skilled surgeon in low volume center.

Surgical resection is the only curative treatment for pancreatic ductal adenocarcinoma (PDAC). Currently, the TNM classification system is considered the standard for predicting prognosis after surgery. However, the prognostic accuracy of the system remains limited. This study aimed to develop new predictive nomograms for resected PDAC. The clinicopathological data of patients who underwent surgery for PDAC between 2006 and 2015 at five major institutions were retrospectively reviewed; 885 patients were included in the analysis. Cox regression analysis was performed to investigate prognostic factors for recurrence and survival, and statistically significant factors were used for creating nomograms. The nomogram for predicting recurrence-free survival included nine factors: sarcopenic obesity, elevated carbohydrate antigen 19–9, platelet-to-lymphocyte ratio, preoperatively-identified arterial abutment, estimated blood loss (EBL), tumor differentiation, size, lymph node ratio, and tumor necrosis. The nomogram for predicting overall survival included 10 variables: age, underlying liver disease, chronic kidney disease, preoperatively found portal vein invasion, portal vein resection, EBL, tumor differentiation, size, lymph node metastasis, and tumor necrosis. The time-dependent area under the receiver operating characteristic curve for both nomograms exceeded 0.70. Nomograms were developed for predicting survival after resection of PDAC, and the platforms showed fair predictive performance. These new comprehensive nomograms provide information on disease status and are useful for determining further treatment for PDAC patients.

A family of self-normalized CUSUM tests for structural change under long memory is proposed. The test statistics apply non-parametric kernel-based long-run variance estimators and have well-defined limiting distributions that only depend on the long-memory parameter. A Monte Carlo simulation shows that these tests provide finite sample size control while outperforming competing procedures in terms of power.

Robotic pancreatectomy, which has received attention in recent years, is subdivided into robotic distal pancreatectomy and robotic pancreatoduodenectomy. Benign and borderline malignant pancreatic tumors can be treated with robotic pancreatectomy, which has several advantages inherent to robotic surgery. The indications for robotic pancreatectomy are similar to those of laparoscopic pancreatectomy, and there are no absolute contraindications. The perioperative outcomes of robotic pancreatectomy are comparable to those of open or laparoscopic pancreatectomy. A high spleen preservation rate, low intraoperative blood loss, and a low open conversion rate are advantages of robotic pancreatectomy. Although robotic pancreatectomy is possible for the treatment of pancreatic cancer, appropriate case selection is required, and more research is needed. Copyright (C) 2022, Society of Gastrointestinal Intervention.

Background: Splenic vessel preserving distal pancreatectomy is difficult operation because of manipultaing small blood vessel without injury of splenic artery and vein.There is a report that robotic single site plus one port distal pancreatectomy is feasible and safe, but only a few cases were performed with vessel preservation.Recently, we experienced first case of robotic single site plus one port splenic vessel preserving distal pancreatectomy.Methods: This operation was first case of robotic distal pancreatectomy in our institution.A 56 years-old male was diagnosed with neuroendocrine tumor.The preoperative image studies revealed a 1.7 cm sized avid enhancing mass with focal calcification at far tail of pancreas.The patient was scheduled to undergo single site plus one port robotic distal pancreatectomy (Davinci-Xi).Results: Robotic single site plat form was used through umbilical incision and additional 12 mm port was used at left side of umbilicus.Robotic camera, one robotic single site arm and assistant's instrument was used through umbilical port, and the other robotic endo-wrist function instrument was used through additional 12 mm port.The total operation time was 135 minutes and the estimated blood loss was 10 mL without transfusion.The operation proceeded from the splenic hilum to the pancreas body with identifying and preservation of splenic artery and vein.The biopsy revealed R0 resection.The patient recovered well without complication, and was discharged on the 6th postoperative day.Conclusions: Robotic single site plus one port splenic vessel preserving distal pancreatectomy was feasible and safe for far pancreas tail mass.

We aimed to examine the predictive value of changes in perioperative carbohydrate antigen (CA) 19-9 levels for patients operated for perihilar cholangiocarcinoma (pCCA). A total of 322 patients who underwent curative resection for pCCA were divided into three groups: normal preoperative CA19-9 (CA19-9 ≤ 37 U/mL), normalization (preoperative CA19-9 > 37 U/mL, postoperative CA19-9 ≤ 37 U/mL), and non-normalization (pre- and postoperative CA19-9 > 37 U/mL) groups. The association of clinicopathological factors with overall survival (OS) was investigated. The non-normalization group (n = 82) demonstrated significantly worse OS than the normal CA19-9 (n = 114) and normalization (n = 126) groups (5-year OS, 16.9%, 29.4%, and 34.4%, respectively; both p ≤ 0.001). The cutoff points of 300 U/mL for preoperative (p = 0.001) and 37 U/mL for postoperative (p < 0.001) CA19-9 levels showed the strongest prognostic values. In the non-normalization group, patients who underwent R1 resection displayed significantly worse OS than those who underwent R0 resection (median OS, 10.2 vs. 15.7 months; p = 0.016). Multivariate analysis revealed that lymph node metastasis (hazard ratio (HR), 2.07; p < 0.001), postoperative CA19-9 > 37 U/mL (HR, 1.94; p < 0.001), transfusion (HR, 1.74; p = 0.002), and T stage (T3,4) (HR, 1.67; p = 0.006) were related to worse OS. Persistent high CA19-9 level after resection of pCCA and R1 resection, especially in the non-normalization group, was associated with poor OS. A high postoperative CA19-9 level was an independent prognostic factor in resected pCCA.

Introduction:To evaluate the predictive factors associated with the early recurrence of early-stage pancreatic ductal adenocarcinoma (PDAC).Methods: This study enrolled 407 patients with stage I PDAC undergoing upfront surgical resection between January 2000 and April 2016.Early recurrence was defined as a diagnosis of recurrence within 6 months of surgery.The optimal cutoff values were determined by receiver operating characteristic (ROC) analyses.Univariate and multivariate analyses were performed to identify the risk factors for early recurrence.Results: Of the 407 patients, 304 (74.7%) experienced disease recurrence within a median time of 10 months.Among 98 patients (24.1%) with early recurrence, 26 (26.5%) and 72 (73.5%) experienced local and distant recurrences, respectively.In total, 253 (62.2%) patients received adjuvant chemotherapy.The optimal cutoff values for early recurrence were 70 U/mL and 2.85 cm for carbohydrate antigen (CA) 19-9 levels and tumor size, respectively, on ROC curve analysis.Of 181 patients with CA 19-9 levels of > 70 U/mL, 59 (32.6%) had early recurrence, compared to 39 (17.4%) among 226 patients with CA 19-9 levels of ≤ 70 U/mL (p < 0.001).Multivariate analysis revealed that a CA 19-9 level of > 70 U/mL (p = 0.006), tumor size > 2.85 cm (p = 0.004), poor differentiation (p = 0.008), and non-adjuvant chemotherapy (p = 0.025) were significant risk factors for early recurrence in early-stage PDAC.Conclusions: Elevated CA 19-9 level (cutoff value > 70 U/mL) can be a reliable predictive factor for early recurrence in early-stage PDAC.As adjuvant chemotherapy can prevent early recurrence, it should be recommended for patients susceptible to early recurrence.

RAS was associated with acceptable procedure-related morbidity and mortality as well as appropriate oncologic outcomes for HCC patients.

Early recurrence in pancreatic ductal adenocarcinoma (PDAC) is a decisive factor in determining a patient's prognosis. We determined in our current study whether circulating tumour cells (CTCs) exist in the blood of PDAC patients and can be used as a predictor of recurrence patterns (i.e. time and site) after surgical resection. Between December 2017 and November 2018, the mononuclear cell layer was obtained from the peripheral blood of 36 patients diagnosed with PDAC. CTCs were then isolated using the CD-PRIME™ platform and detected via immunostaining. The patient records were analyzed to correlate these data with survival and recurrence patterns. Twelve patients were CTC-positive (33.3%) and showed a significantly frequent rate of systemic recurrence (distant metastases and peritoneal dissemination) (p = 0.025). On multi-variable logistic regression analysis, CTC positivity was an independent risk factor for early recurrence (p = 0.027) and for systemic recurrence (p = 0.033). In summary, the presence or absence of CTC in the blood of the patients with PDAC could help predict the recurrence pattern after surgery. PDAC patients with CTC positivity at tumour diagnosis should therefore undergo a comprehensive strategy for systemic therapy and active monitoring to detect possible early recurrence.

BACKGROUND:Pancreatic ductal adenocarcinoma (PDAC) is a serious disease with a poor prognosis. Only a minority of patients undergo surgery due to the advanced stage of the disease, and patients with early-stage disease, who are expected to have a better prognosis, often experience recurrence. Thus, it is important to identify the risk factors for early recurrence and to develop an adequate treatment plan. AIM:To evaluate the predictive factors associated with the early recurrence of early-stage PDAC. METHODS:This study enrolled 407 patients with stage I PDAC undergoing upfront surgical resection between January 2000 and April 2016. Early recurrence was defined as a diagnosis of recurrence within 6 mo of surgery. The optimal cutoff values were determined by receiver operating characteristic (ROC) analyses. Univariate and multivariate analyses were performed to identify the risk factors for early recurrence. RESULTS:Of the 407 patients, 98 patients (24.1%) experienced early disease recurrence: 26 (26.5%) local and 72 (73.5%) distant sites. In total, 253 (62.2%) patients received adjuvant chemotherapy. On ROC curve analysis, the optimal cutoff values for early recurrence were 70 U/mL and 2.85 cm for carbohydrate antigen 19-9 (CA 19-9) levels and tumor size, respectively. Of the 181 patients with CA 19-9 level > 70 U/mL, 59 (32.6%) had early recurrence, compared to 39 (17.4%) of 226 patients with CA 19-9 level ≤ 70 U/mL (P < 0.001). Multivariate analysis revealed that CA 19-9 level > 70 U/mL (P = 0.006), tumor size > 2.85 cm (P = 0.004), poor differentiation (P = 0.008), and non-adjuvant chemotherapy (P = 0.025) were significant risk factors for early recurrence in early-stage PDAC. CONCLUSION:Elevated CA 19-9 level (cutoff value > 70 U/mL) can be a reliable predictive factor for early recurrence in early-stage PDAC. As adjuvant chemotherapy can prevent early recurrence, it should be recommended for patients susceptible to early recurrence.

Background: Incidentally detected, small nonfunctioning pancreatic neuroendocrine tumors (NF-PNETs) are increasingly diagnosed on imaging modalities. This retrospective investigation evaluated the clinicopathologic characteristics and perioperative and oncologic outcomes in patients with small NF-PNETs undergoing curative resection. Methods: The medical records of 444 patients who underwent pancreatic resection for NF-PNETs at a single, large-volume institution between January 2000 and December 2018 were retrospectively reviewed. Patients were divided into those with small (=2 cm) and large (>2 cm) tumors based on the largest tumor diameter on preoperative computed tomography (CT). Outcomes were also evaluated in subgroups of patients with small NF-PNET who did and did not undergo lymphadenectomy. Results: Of the 444 patients with NF-PNETs, 195 (43.9%) had small (=2 cm) and 249 (56.1%) had large (>2 cm) NF-PNETs. The rate of parenchyma-preserving surgery (14.4% vs. 7.2%, p = 0.014) and the ratio of spleen preservation for left-sided pancreatectomy (65.6% vs. 38.3%, p < 0.001) were higher in the small NF-PNET group. Size on CT >2 cm (p < 0.001, hazard ratio [HR]: 5.836, 95% confidence interval [CI]: 2.474-13.769), presence of perineural invasion (p < 0.001, HR: 3.025, 95% CI: 1.640-5.577), World Health Organization (WHO) Grade 2 (p = 0.007, HR: 2.861, 95% CI: 1.325-6.176), and WHO Grade 3 (p < 0.001, HR: 11.537, 95% CI: 5.282-25.199) were independent predictors of disease-free survival (DFS). DFS did not differ significantly in patients with small NFPNETs who did and did not undergo lymphadenectomy (p = 0.886). Conclusions: Assessment of long-term oncologic outcomes suggests that surgical resection may cure small NF-PNETs. Minimally invasive surgery and organ-preserving surgery are acceptable treatment options for select patients with small NF-PNETs. The effect on survival outcomes of lymph node dissection for small NF-PNETs remains unclear.

Radical antegrade modular pancreatosplenectomy (RAMPS) is considered an effective procedure for left-sided pancreatic ductal adenocarcinoma (PDAC). However, whether there are differences in perioperative outcomes, pathologies, or survival outcomes between anterior RAMPS (aRAMPS) and posterior RAMPS (pRAMPS) has not been reported previously. We retrospectively reviewed and compared the demographic, perioperative, histopathologic, and survival data of patients who underwent aRAMPS or pRAMPS for PDAC. We also compared these two groups among patients without periadrenal infiltration or adrenal invasion. A total of 112 aRAMPS patients and 224 pRAMPS patients were evaluated. Periadrenal infiltration, neoadjuvant treatment, and concurrent vessel resection were more prevalent in the pRAMPS group. After excluding patients with periadrenal infiltration, 106 aRAMPS patients were compared with 157 pRAMPS patients. There were no significant differences between the aRAMPS and pRAMPS groups in the pathologic tumor size, resection margin, proportion of tangential margin in the R1 resection, and number of harvested lymph nodes. The median overall survival and disease-free survival also did not differ significantly between the two groups. We cautiously suggest that pRAMPS will not necessarily provide more beneficial histopathologic outcomes and survival rates for left-sided PDAC cases without periadrenal infiltration. If periadrenal infiltration is not suspected, aRAMPS alone should be sufficiently effective.

PurposeThis study was conducted to evaluate the prognostic values of the 7th and 8th American Joint Committee on Cancer (AJCC) staging systems for patients with resected perihilar cholangiocarcinoma (PHCC).Materials and MethodsA total of 348 patients who underwent major hepatectomy for PHCC between 2008 and 2015 were identified from a single center. Overall survival (OS) was estimated using the Kaplan-Meier method and compared across stage groups with the log-rank test. The concordance index was used to evaluate the prognostic predictability of the 8th AJCC staging system compared with that of the 7th.ResultsIn the 8th edition, the stratification of each group of T classification improved compared to that in the 7th, as the survival rate of T4 decreased (T2, 31.2%; T3, 13.9%; T4, 15.1%; T1- T2, p=0.260; T2-T3, p=0.001; T3-T4, p=0.996). Both editions showed significant survival differences between each N category, except between N1 and N2 (p=0.063) in 7th edition. Differences of point estimates between the 8th and 7th T and N classification and overall stages were +0.028, +0.006, and +0.039, respectively (T, p=0.005; N, p=0.115; overall stage, p=0.005). In multivariable analysis, posthepatectomy liver failure, T category, N category, distant metastasis, histologic differentiation, intraoperative transfusion, and resection margin status were associated with OS.ConclusionThe prognostic predictability of 8th AJCC staging for PHCC improved slightly, with statistical significance, compared to the 7th edition, but its overall performance is still unsatisfactory.