Outcomes of Distal Pancreatectomy With Celiac Axis Resection for Pancreatic Cancer.

OBJECTIVES: This study aimed to show the clinical and oncologic outcomes of distal pancreatectomy with celiac axis resection (DP-CAR) from a high-volume single center and analyze them from diverse perspectives. METHODS: Forty-eight patients with pancreatic body and tail cancer with celiac axis involvement who underwent DP-CAR were included in the study. The primary outcome was morbidity and 90-day mortality, and the secondary outcome was overall survival and disease-free survival. RESULTS: Morbidity (Clavien-Dindo classification grade ≥3) occurred in 12 patients (25.0%). Thirteen patients (27.1%) had pancreatic fistula grade B and 3 patients (6.3%) had delayed gastric emptying. The 90-day mortality was 2.1% (n = 1). The median overall survival was 25.5 months (interquartile range, 12.3-37.5 months) and median disease-free survival was 7.5 months (interquartile range, 4.0-17.0 months). During the follow-up period, 29.2% of participants survived for up to 3 years and 6.3% survived for up to 5 years. CONCLUSIONS: Despite its associated morbidity and mortality, DP-CAR should be considered as the only therapeutic option for pancreatic body and tail cancer with celiac axis involvement when carried out on carefully selected patients performed by a highly experienced group.

Laparoscopic versus open pancreaticoduodenectomy with major vein resection for pancreatic head cancer.

BACKGROUND/PURPOSE: Laparoscopic pancreaticoduodenectomy (PD) with major vein resection is a challenging procedure. Herein, we evaluated the feasibility and safety of laparoscopic vein resection in pancreatic head cancer with portal vein/superior mesenteric vein (PV/SMV) invasion, and compared the survival rate following laparoscopic surgery with that following open surgery. METHODS: We retrospectively reviewed the electronic medical records of all patients with pancreatic head cancer who underwent surgery performed by a single surgeon from January 2015 to December 2017. Kaplan-Meier curves were plotted to compare the disease-free survival, while Cox-proportional hazard models were used to analyze prognostic factors for survival. RESULTS: Among 76 patients, 63 underwent open PD and 13 underwent laparoscopic PD with PV/SMV resection. There was no significant difference in the rate of complications, including portal vein stenosis and portal vein thrombus, recurrence of tumors, or pathological outcomes after surgery between the groups. There was also no significant difference in disease-free survival (p = .803) between the two groups. Additionally, the surgical method was not an independent prognostic factor for disease-free survival. CONCLUSIONS: Laparoscopic PD with major vein resection can be feasibly performed in select patients with abutment and focal narrowing of the PV/SMV in pancreatic head cancer.

Mixed adenoneuroendocrine carcinoma of the ampulla of Vater: Three case reports and a literature review.

Mixed adenoneuroendocrine carcinoma is defined as a tumor with a mixture of adenocarcinoma components and neuroendocrine neoplasm components. Each of these two components of mixed adenoneuroendocrine carcinoma accounts for at least 30% of all tumors. Mixed adenoneuroendocrine carcinoma might be located in the ampulla of Vater, a very rare location compared to other organs. Thus, its treatment and prognosis plans have not been established yet. We report three cases of mixed adenoneuroendocrine carcinoma occurring in the ampulla of Vater. Each patient had a different clinical course. In general, difficulty in preoperative diagnosis, risk of early recurrence, and poor disease course were main hallmarks of mixed adenoneuroendocrine carcinoma arising from the ampulla of Vater. However, one patient in this case report survived although she did not receive adjuvant chemotherapy due to her old age. Therefore, it is important to establish a careful treatment strategy for mixed adenoneuroendocrine carcinoma arising from the ampulla of Vater.

Minimally invasive versus open pancreaticoduodenectomy for distal bile duct cancer: an inverse probability of treatment weighting analysis of outcomes.

BACKGROUND: Minimally invasive pancreaticoduodenectomy (MIPD) has been extended to periampullary cancers, but the oncologic outcome of MIPD for distal bile duct cancer (DBDC) has not been confirmed yet. METHODS: Patients who underwent pancreaticoduodenectomy (PD) for DBDC of stage I-IIb from 2015 to 2019 at a tertiary referral center were identified and divided into open PD (OPD) and MIPD groups, the latter including laparoscopic and robotic procedures. Survival was compared between the two groups after inverse probability of treatment weighting (IPTW) using predetermined factors, and exploratory mediation analysis was performed using surgery-derived outcomes. RESULTS: MIPD (n = 81) group had more female patients (46.9% vs 31.6%, p = 0.011) and longer operation time (366.2 min vs. 279.1 min, p < 0.001) than the OPD (n = 288) group before IPTW. Otherwise, intraoperative and immediate postoperative outcomes were comparable between the two groups. In oncologic outcomes, MIPD group showed comparable 3-year overall survival (78.2% vs 75.0%, p = 0.062) and recurrence-free survival (51.2% vs 53.4%, p = 0.871) rates with OPD group before IPTW, and MIPD was not related with survival (hazard ratio [HR] 0.61, 95% confidence interval [CI] 0.29-1.26, p = 0.18) and recurrence (HR 1.01, 95% CI 0.67-1.53, p = 0.949) after IPTW with consideration of potential mediators. Sensitivity analysis using propensity score matching also showed similar results for survival (HR 0.68, 95% CI 0.32-1.44, p = 0.312) and recurrence (HR 1.12, 95% CI 0.67-1.88, p = 0.653). CONCLUSION: MIPD and OPD groups showed similar postoperative and oncologic outcomes. MIPD could be a considerable treatment option without oncological compromise in high-volume centers.

Real-world outcomes of adjuvant gemcitabine versus gemcitabine plus capecitabine for resected pancreatic ductal adenocarcinoma.

Background: Adjuvant chemotherapy is the standard treatment after curative-intent surgery for pancreatic ductal adenocarcinoma (PDAC). The phase-3 ESPAC-4 trial demonstrated significantly improved overall survival (OS) with Gemcitabine plus capecitabine (GemCap) over Gemcitabine (Gem) in Europe. We conducted a retrospective efficacy and safety evaluation of GemCap versus Gem in an Asian population. Methods: This retrospective analysis included 292 patients with PDAC who received adjuvant Gem or GemCap after curative resection between January 2017 and December 2020 at Asan Medical Center, Seoul, Korea. Results: Adjuvant Gem and GemCap were administered to 161 (55.1%) and 131 (44.8%) patients, respectively. The Gem group had significantly older patients (median 66 versus 63 years, p = 0.001); otherwise, the groups had similar baseline characteristics. With median follow-up durations of 39.4 [95% confidence interval (CI), 36.9-45.0] and 39.4 (95% CI, 34.7-41.6) months in the Gem and GemCap groups, the median OS was 36.8 (95% CI, 29.7-43.5) and 46.1 (95% CI, 31.5-not reached) months in the Gem and GemCap groups, respectively [unadjusted hazard ratio (HR) = 0.7; 95% CI, 0.5-1.0; p = 0.07). The median recurrence-free survival was 14.3 (95% CI, 12.9-17.7) and 17.0 (95% CI, 13.3-28.2) months, respectively (p = 0.5). Hand-foot skin reactions (any grade, 15.3% versus 0.6%; p < 0.001), neutropenia (78.6% versus 67.7%, p = 0.04) and thrombocytopenia (30.5% versus 20.5%, p = 0.04) were more common in the GemCap group. Multivariate analysis revealed adjuvant GemCap - compared with Gem - to be significantly associated with better OS (adjusted HR = 0.6; 95% CI, 0.4-0.9; p = 0.01). Otherwise, moderate or poor histological grade, lymph node positivity, positive resection margin, and elevated CA 19-9 (>median) were significantly associated with worse OS. Conclusions: Adjuvant GemCap showed the consistent clinical outcomes with the ESPAC-4 trial. As mFOLFIRINOX is the new standard treatment for medically fit patients with resected PDAC, further evaluation of optimal adjuvant chemotherapy in daily practice is warranted.

Minimally invasive distal pancreatectomy: Chronologic changes in the trends and clinical outcomes through a 15-year, single-center experience with 2212 patients.

BACKGROUND: We identified the chronologic changes in the clinical outcomes of minimally invasive distal pancreatectomy (MIDP) for left-sided pancreatic tumors in a single high-volume center over a period of 15 years. METHODS: Between 2005 and 2019, 2212 patients underwent planned MIDP. Chronologic changes were analyzed according to 5-year intervals (P1, P2, P3). Furthermore, we assessed the prognostic factors of open conversion and postoperative complications. RESULTS: Minimally invasive distal pancreatectomy has steadily increased during the last 15 years when compared to open distal pancreatectomy, from 10.8% to 84.9%. Also, MIDP for pancreatic ductal adenocarcinoma (PDAC) has been steadily increasing from 5.6% to 68.4%. According to the 5-year intervals, lengths of hospital stay decreased, but age and American Society of Anesthesiologists (ASA) ≥3 increased; conversely, the rates of Clavien-Dindo classification ≥grade 3 (9.5%) and postoperative pancreatic fistula (39.7%) showed no differences. The 90-day mortality and open conversion rates were 0.2% and 3.5%, respectively. Multivariate logistic regression analysis revealed malignancy and extended pancreatectomy were risk factors for open conversion. Furthermore, the poor prognostic factors for severe complications were malignancy, extended pancreatectomy, and ASA ≥3. CONCLUSION: Minimally invasive distal pancreatectomy has become a popular procedure not only for benign cases but also for malignant ones. However, well-organized training, experience and skill are necessary, especially for poor-performance patients and extensively malignant conditions.

Predictive Performance of Current Nodal Staging Systems in Various Categories of Pancreatic Cancer.

BACKGROUND: Nodal staging systems (NSS) for pancreatic ductal adenocarcinoma (PDAC) classify patients on the basis of number of metastatic lymph nodes (MLN), metastatic/retrieved lymph node ratio (LNR), and log odds of positive LN (LODDS). The relative prognostic performance of these NSS, however, remains unclear. PATIENTS AND METHODS: We identified 2584 patients who underwent surgery for PDAC between 2010 and 2019. Subgroups of each staging system were classified using K-adaptive partitioning method and assessed by comparing time-dependent areas under the curve (AUC) 5 years after surgery. RESULTS: Patients were subgrouped by MLN (0, 1-3, ≥ 4), LNR (0, 0-0.23, > 0.23), and LODDS (< - 3.5, - 3.5 to - 0.970, > - 0.97). All three NSS were independent prognostic factors for overall survival (OS) and recurrence-free survival (RFS). The AUCs for OS were comparable for the MLN (0.622), LNR (0.609), and LODDS (0.596) systems. Subgroup evaluation based on 12 retrieved lymph nodes (RLN), R1 resection, and extent of resection showed that the AUCs of the MLN and LNR NSS were comparable for OS and RFS regardless of the number of RLNs, R1 resection, and extent of resection. By contrast, the AUCs of the LODDS NSS were lower. CONCLUSION: The NSS based on the number of MLN is the best prognostic indicator, with prognostic performance comparable to the other NSS and greater convenience for practical use. This NSS was applicable regardless of the numbers of RLN, R1 resection, and extent of resection.

Usefulness of Inflammation-Based Prognostic Scores in Patients with Surgically Treated Pancreatic Ductal Adenocarcinoma.

In this study, we evaluated the prognostic value of inflammation-based prognostic scores in patients undergoing curative surgery for pancreatic ductal adenocarcinoma (PDAC). A retrospective analysis was conducted for 914 patients undergoing curative surgical resection for PDAC between January 2011 and April 2016. Inflammation-based scores of modified Glasgow Prognostic Score (mGPS), neutrophil-lymphocyte ratio, and platelet-lymphocyte ratio were assessed. mGPS was classified as high (1 or 2) or low (0). Median age was 63 (range, 33-88) years; 538 patients (58.9%) were male. A high mGPS was independently associated with poor overall survival (OS) and disease-free survival (DFS) (median OS: 25.4 months vs. 20.4 months, p = 0.001; median DFS: 11.6 months vs. 9.3 months, p = 0.002), poor OS in patients with TNM stage I PDAC (44 months vs. 24.8 months, p = 0.001), and poor OS and DFS in patients with tumors located at the pancreatic head or uncinate process (OS: 25.4 months vs. 20.4 months; p = 0.007, DFS: 11.4 months vs. 8.87 months; p = 0.005). Preoperative mGPS was a significant prognostic factor for PDAC after curative resection; thus, mGPS can be a useful prognostic predictive factor in patients with TNM stage I PDAC, especially for tumors located at the head and uncinate.

Preoperative serum carbohydrate antigen 19-9 levels predict early recurrence after the resection of early-stage pancreatic ductal adenocarcinoma.

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.

Analysis of KRAS Mutation Subtype in Tissue DNA and Cell-Free DNA Using Droplet Digital PCR and the Function of Cell-Free DNA as a Recurrence Predictive Marker in Pancreatic Cancer.

KRAS mutation is a major regulator in the tumor progression of pancreatic cancer. Here, we compared the frequency and mutation burden of KRAS mutation subtypes with paired tumor tissue and blood in patients and examined their clinical significance. DNA from tumor tissues and cell-free DNA (cfDNA) from preoperative blood were obtained from 70 patients with pancreatic cancer. Subtypes and mutation burdens of KRAS G12D and G12V mutations were evaluated using droplet digital PCR. Comparing the presence of mutations in tissue, accumulative and simultaneous mutations of G12D or G12V were identified of 67 (95.7%), and 48 patients (68.6%). Conversely, in blood, they were only identified in 18 (25.7%) and four (5.7%) patients; respectively. Next, comparing the mutation burden in tissue, the mutation burden varied from less than 0.1 to more than five, whereas that of cfDNA in blood was mostly between one and five, as cases with a mutation burden lower than 0.1 and higher than five were rare. Finally, the presence of the G12V mutation alone in cfDNA and the combination of the G12V mutation with elevated CA 19-9 levels were associated with poor recurrence-free survival. These fundamental data on the KRAS mutation subtypes and their clinical significance could support their potential as predictive markers for postoperative recurrence.

The clinicopathologic and operative characteristics of patients with small nonfunctioning pancreatic neuroendocrine tumors.

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 NF-PNETs 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.

Arterial resection during pancreatectomy for pancreatic ductal adenocarcinoma with arterial invasion: A single-center experience with 109 patients.

Pancreatectomy for pancreatic cancer with arterial invasion is controversial and performed infrequently. As its indication evolves and neoadjuvant chemotherapy also evolves, it is meaningful to identify short- and long-term outcomes of pancreatectomy with arterial resection (AR). This study aimed to retrospectively analyze the clinical outcomes of pancreatectomy with AR for pancreatic ductal adenocarcinoma.Patients with pancreatic ductal adenocarcinoma treated with pancreatectomy with AR at our institute between January 2000 and April 2017 were retrospectively reviewed. Operative outcome and survival were compared according to the presence of neoadjuvant chemotherapy.This study included 109 patients (38 underwent surgery after neoadjuvant chemotherapy, 71 underwent upfront surgery). The median hospital stay was 17 (interquartile range, 12-26.5) days. Clinically relevant postoperative pancreatic fistula (grade B or C) occurred in 14 patients (12.8%). The major morbidity (≥grade III) and mortality rates were 26.6% and 0.9%, respectively. R0 resection was achieved in 80 patients (73.4%). Microscopic actual tumor invasion into the arterial wall was identified in 25 patients (22.9%). The median overall survival (OS) of all patients was 18.4 months. The neoadjuvant chemotherapy group showed better OS than the upfront surgery group, without statistical significance (25.3 vs 16.2 months, P = .06). Progression-free survival was better in patients with neoadjuvant chemotherapy (13.2 vs 7.1 months, P = .01). Patients with partial response to neoadjuvant chemotherapy showed better OS than those with stable disease (33.7 vs 17.5 months, P = .04).Pancreatectomy with AR for advanced pancreatic cancer showed acceptable procedure-related morbidity and mortality. A survival benefit of neoadjuvant chemotherapy was identified, compared to upfront surgery.

Predictive Factors Associated with Complications after Laparoscopic Distal Pancreatectomy.

Although laparoscopic distal pancreatectomy (LDP) has become more popular, the postoperative complication rate remains high. We sought to identify the risk factors for post-LDP complications. We examined 1227 patients who underwent LDP between March 2005 and December 2015 at a single large-volume center. We used logistic regression for the analysis. The overall (13.2%) and major (3.3%) complication rates were determined. Postoperative pancreatic fistula was the most frequent complication, and 58 patients (4.7%) had clinically significant (grade B) pancreatic fistulas. No 90-day mortality was recorded. Long operative time (≥200 min), large estimated blood loss (≥320 mL), LDP performed by an inexperienced surgeon (<50 cases), and concomitant splenectomy were identified as risk factors for overall complications using a logistic regression model. For major complications, male sex (p = 0.020), long operative time (p = 0.005), and LDP performed by an inexperienced surgeon (p = 0.026) were significant predictive factors. Using logistic regression analysis, surgery-related factors, including long operative time and LDP performed by an inexperienced surgeon, were correlated with overall and major complications of LDP. As LDP is a technically challenging procedure, surgery-related variables emerged as the main risk factors for postoperative complications. Appropriate patient selection and sufficient surgeon experience may be essential to reduce the complications of LDP.

A Comparative Study of Laparoscopic versus Open Pancreaticoduodenectomy for Ampulla of Vater Carcinoma.

Several studies have compared laparoscopic pancreaticoduodenectomy (LPD) and open pancreaticoduodenectomy (OPD) in patients with periampullary carcinoma; however, only a few studies have made such a comparison on patients with ampulla of Vater cancer (AVC). We compared the perioperative and oncologic outcomes between LPD and OPD in patients with AVC using propensity-score-matched analysis. A total of 359 patients underwent PD due to AVC during the study period (76 LPD, 283 OPD). After propensity score matching, the LPD group showed significantly longer operation time than did the OPD group (400.2 vs. 344.6 min, p < 0.001). Nevertheless, the LPD group had fewer painkiller administrations (8.3 vs. 11.1, p < 0.049), fewer Grade II or more severe postoperative complications (15.9% vs. 34.8%, p = 0.012), and shorter postoperative hospital stays (13.7 vs. 17.3 days, p = 0.048), compared with the OPD group. There was no significant difference in recurrence-free outcomes and overall survival between the two groups (p = 0.754 and 0.768, respectively). Compared with OPD, LPD for AVC had comparative oncologic outcomes with less pain, less postoperative morbidity, and shorter hospital stays. LPD may serve as a promising alternative to OPD in patients with AVC.

Association between Metformin Use and Clinical Outcomes Following Pancreaticoduodenectomy in Patients with Type 2 Diabetes and Pancreatic Ductal Adenocarcinoma.

Retrospective studies on the association between metformin and clinical outcomes have mainly been performed on patients with non-resectable pancreatic ductal adenocarcinoma and may have been affected by time-related bias. To avoid this bias, recent studies have used time-varying analysis; however, they have only considered the start date of metformin use and not the stop date. We studied 283 patients with type 2 diabetes and pancreatic ductal adenocarcinoma following pancreaticoduodenectomy, and performed analysis using a Cox model with time-varying covariates, while considering both start and stop dates of metformin use. When start and stop dates were not considered, the metformin group showed significantly better survival. Compared with previous studies, adjusted analysis based on Cox models with time-varying covariates only considering the start date of postoperative metformin use showed no significant differences in survival. However, although adjusted analysis considering both start and stop dates showed no significant difference in recurrence-free survival, the overall survival was significantly better in the metformin group (Hazard ratio (HR), 0.747; 95% confidence interval (CI), 0.562-0.993; p = 0.045). Time-varying analysis incorporating both start and stop dates thus revealed that metformin use is associated with a higher overall survival following pancreaticoduodenectomy in patients with type 2 diabetes and pancreatic ductal adenocarcinoma.

Comparison of Minimally Invasive Versus Open Pancreatoduodenectomy for Pancreatic Ductal Adenocarcinoma: A Propensity Score Matching Analysis.

Background: Few studies have compared perioperative and oncological outcomes between minimally invasive pancreatoduodenectomy (MIPD) and open pancreatoduodenectomy (OPD) for pancreatic ductal adenocarcinoma (PDAC). Methods: A retrospective review of patients undergoing MIPD and OPD for PDAC from January 2011 to December 2017 was performed. Perioperative, oncological, and survival outcomes were analyzed before and after propensity score matching (PSM). Results: Data from 1048 patients were evaluated (76 MIPD, 972 OPD). After PSM, 73 patients undergoing MIPD were matched with 219 patients undergoing OPD. Operation times were longer for MIPD than OPD (392 vs. 327 min, p < 0.001). Postoperative hospital stays were shorter for MIPD patients than OPD patients (12.4 vs. 14.2 days, p = 0.040). The rate of overall complications and postoperative pancreatic fistula did not differ between the two groups. Adjuvant treatment rates were higher following MIPD (80.8% vs. 59.8%, p = 0.002). With the exception of perineural invasion, no differences were seen between the two groups in pathological outcomes. The median overall survival and disease-free survival rates did not differ between the groups. Conclusions: MIPD showed shorter postoperative hospital stays and comparable perioperative and oncological outcomes to OPD for selected PDAC patients. Future randomized studies will be required to validate these findings.

A Novel Biodegradable Tubular Stent Prevents Pancreaticojejunal Anastomotic Stricture.

Stricture of pancreatic-enteric anastomoses is a major late complication of a pancreaticoduodenectomy for the treatment of a periampullary tumor and can lead to exocrine and endocrine insufficiency such as malnutrition and diabetes mellitus. We investigated the safety and efficacy of a biodegradable tubular stent (BTS) for preventing a pancreaticojejunostomy (PJ) anastomotic stricture in both a rat and porcine model. The BTS was manufactured using a terpolymer comprising poly p-dioxanone, trimethylene carbonate, and glycolide. A cohort of 42 rats was randomized into 7 groups of 6 animals each after BTS placement into the duodenum for the biodegradation assay. A total of 12 pigs were randomized equally into a control and BTS placement group. The effectiveness of the BTS was assessed by comparing radiologic images with histologic results. Surgical procedures and/or BTS placements were technically successful in all animals. The median mass losses of the removed BTS samples from the rat duodenum were 2.1, 6.8, 11.2, 19.4, 26.1, and 56.8% at 1, 2, 3, 4, 6, and 8 weeks, respectively. The BTS had completely degraded at 12 weeks in the rats. In the porcine PJ model, the mean luminal diameter and area of the pancreatic duct in the control group was significantly larger than in the BTS group (all p < 0.05). BTS placement thus appears to be safe and effective procedure for the prevention of PJ anastomotic stricture. These devices have the potential to be used as a temporary stent placement to treat pancreatic-enteric anastomoses, but further investigations are required for optimization in human.

Robotic versus laparoscopic distal pancreatectomy for left-sided pancreatic tumors: a single surgeon's experience of 228 consecutive cases.

BACKGROUND: Laparoscopic distal pancreatectomy (LDP) has gained popularity for the treatment of left-sided pancreatic tumors. Robotic systems represent the most recent advancement in minimally invasive surgical treatment for such tumors. Theoretically, robotic systems are considered to have several advantages over laparoscopic systems. However, there have been few studies comparing both systems in the treatment of distal pancreatectomy. We compared perioperative and oncological outcomes between the two treatment modalities. METHODS: A retrospective analysis was conducted of all consecutive minimally invasive distal pancreatectomy cases performed by a single surgeon at a high-volume center between January 2015 and December 2017. RESULTS: The analysis included 228 consecutive patients (LDP, n = 182; Robotic-assisted laparoscopic distal pancreatectomy [R-LDP], n = 46). Operative time was significantly longer in the R-LDP group than in the LDP group (166.4 vs. 140.7 min; p = 0.001). In a subgroup analysis of patients who underwent the spleen-preserving approach, the spleen preservation rate associated with R-LDP was significantly higher than that associated with LDP (96.8% vs. 82.5%; p = 0.02). In another subgroup analysis of patients with pancreatic cancer, there were no significant differences in median overall and disease-free survival between the two groups. CONCLUSIONS: R-LDP is a safe and feasible approach with perioperative and oncological outcomes comparable to those of LDP. R-LDP offers an added technical advantage that enables the surgeon to perform a complex procedure with good ergonomic comfort.

Comparative analysis of afferent loop obstruction between laparoscopic and open approach in pancreaticoduodenectomy.

BACKGROUND: Afferent loop obstruction (ALO) is a rare mechanical complication of pancreaticoduodenectomy (PD) and is associated with a high rate of morbidity and mortality. METHODS: Data from patients who underwent PD between May 2007 and July 2017 at a single large-volume center were retrospectively reviewed. RESULTS: Of the 3,223 patients who underwent PD, 67 developed ALO. More patients in the laparoscopic PD (LPD) group had developed ALO due to internal herniation than did those in the open PD (OPD) group (46.2 vs. 4.7%, P < 0.001). Patients in the LPD group also showed earlier occurrence of ALO (ALO occurrence within 60 days: 76.9 vs. 22.2%, P < 0.001) and more frequent requirement for surgical treatment (76.9 vs. 18.9%, P < 0.001) than did those in the OPD group. CONCLUSIONS: The characteristics of ALO were significantly different between patients who had received LPD and OPD. The most common cause of ALO in the LPD group was internal herniation occurring in the early postoperative period. Internal herniation following LPD may be prevented by routine closure of mesocolic window and should be treated by emergency surgery if it occurs.

Prognostic value of adjacent organ resection in patients with left-sided pancreatic ductal adenocarcinoma following distal pancreatectomy.

BACKGROUND: We evaluated whether distal pancreatectomy (DP) with adjacent organ resection (AOR) affected perioperative outcomes and survival in patients with left-sided pancreatic ductal adenocarcinoma (PDAC). METHODS: Retrospective cohort study was conducted at single large volume academic medical center from January 2000 to December 2016. RESULTS: Five hundred and twenty-three patients had undergone standard DP (without additional vessel/organ resection) and 40 had undergone DP with AOR due to adjacent organ infiltration. There were no differences of postoperative morbidity and hospital stay between the two groups. In the patients with AJCC 8th stage I and II PDAC, there were significant differences of median disease-specific and progression-free survivals between the standard and AOR groups (37.9 vs. 20.2 months; P = 0.05, 20 vs. 10 months; P = 0.028, respectively). DP with AOR was identified as independent prognostic factor of stage I and II PDAC by multivariate Cox regression analysis. CONCLUSIONS: Distal pancreatectomy with AOR could be an acceptable surgical treatment for left-sided PDAC. However, AOR group shows poor prognosis than that of the standard group in patients with AJCC 8th stage I and II PDAC. AOR should be considered indicative of a more aggressive tumor in AJCC 8th stage I and II PDAC.