Outcomes after distal pancreatectomy with or without splenectomy for intraductal papillary mucinous neoplasm: international multicentre cohort study.

BACKGROUND: International guidelines on intraductal papillary mucinous neoplasm (IPMN) recommend a formal oncological resection including splenectomy when distal pancreatectomy is indicated. This study aimed to compare oncological and surgical outcomes after distal pancreatectomy with or without splenectomy in patients with presumed IPMN. METHODS: An international, retrospective cohort study was undertaken in 14 high-volume centres from 7 countries including consecutive patients after distal pancreatectomy for IPMN (2005-2019). Patients were divided into spleen-preserving distal pancreatectomy (SPDP) and distal pancreatectomy with splenectomy (DPS). The primary outcome was lymph node metastasis (LNM). Secondary outcomes were overall survival, duration of operation, blood loss, and secondary splenectomy. RESULTS: Overall, 700 patients were included after distal pancreatectomy for IPMN; 123 underwent SPDP (17.6%) and 577 DPS (82.4%). The rate of malignancy was 29.6% (137 patients) and the overall rate of LNM 6.7% (47 patients). Patients with preoperative suspicion of malignancy had a LNM rate of 17.2% (23 of 134) versus 4.3% (23 of 539) among patients without suspected malignancy (P < 0.001). Overall, SPDP was associated with a shorter operating time (median 180 versus 226 min; P = 0.001), less blood loss (100 versus 336 ml; P = 0.001), and shorter hospital stay (5 versus 8 days; P < 0.001). No significant difference in overall survival was observed between SPDP and DPS for IPMN after correction for prognostic factors (HR 0.50, 95% c.i. 0.22 to 1.18; P = 0.504). CONCLUSION: This international cohort study found LNM in 6.7% of patients undergoing distal pancreatectomy for IPMN. In patients without preoperative suspicion of malignancy, SPDP seemed oncologically safe and was associated with improved short-term outcomes compared with DPS.

Intraoperative paraaortic lymph node sampling during resection for pancreatic cancer: evolving role in the modern chemotherapy era.

BACKGROUND: The role of paraaortic lymph node (PALN) sampling for pancreatic cancer (PC) remains controversial. This study aimed to assess the yield of PALN sampling and its impact on long-term outcomes. METHODS: Patients treated from 2005 to 2018 were included. Since 2015, patients with borderline resectable or unresectable (BR/UR) tumours received standardized neoadjuvant therapy (NAT), whereas patients with resectable tumours underwent upfront resection. RESULTS: Among 771 patients with PALN excision, metastasis was confirmed in 76 patients (10%) and 59 proceeded to planned resection. PALN metastasis was associated with early recurrence and shorter survival after upfront resection (1-year recurrence-free rate: 23% vs 57% for resectable tumours, P < 0.001, 9% vs 52% for BR/UR tumours, P = 0.006; median overall survival (OS): 19 vs 31 months for resectable tumours, P < 0.001, 17 vs 23 months for BR/UR tumours, P = 0.057). In contrast, they were both similar between patients with/without PALN metastasis following NAT for BR tumours (1-year recurrence-free rate, 50% vs 58%, P = 0.88; median OS, 28 vs 35 months, P = 0.45, respectively). CONCLUSIONS: Occult metastasis to PALNs is not uncommon in patients with potentially resectable PC. Its prognostic impact depends on the treatment strategy, and the intraoperative decision for resection should be individualized.

An aberrant right hepatic artery arising from the gastroduodenal artery: a pitfall encountered during pancreaticoduodenectomy.

PURPOSE: Among the variations of the right hepatic artery (RHA), the identification of an aberrant RHA arising from the gastroduodenal artery (GDA) is vital for avoiding damage to the RHA during surgery, since ligation of the GDA is necessary during pancreaticoduodenectomy (PD). However, this variation is not frequently reported. The purpose of this study was to focus on an aberrant RHA arising from the GDA, which was not noted in the classifications reported by Michels and Hiatt. METHODS: A total of 574 patients undergoing a PD between Jan 2001 and Dec 2015 at a tertiary care hospital in Switzerland (n = 366) and between Jan 2009 and May 2015 at a hospital in Japan (n = 208) were included in the analysis. Of these, preoperative CT angiography or/and MRI angiography findings were available for 532 patients. We retrospectively analyzed the hepatic artery variations, patient demographics, and surgical outcomes. RESULTS: Among the 532 patients who received a PD, an RHA originating from the GDA was observed in 19 cases (3.5%). Eleven patients (2.1%) had both an aberrant RHA and an aberrant left hepatic artery (LHA) (Hiatt Type 4). Six patients (1.2%) had a replaced CHA arising from the SMA (Hiatt Type 5). We could, therefore, correctly identify the aberration in all cases. CONCLUSIONS: We observed rarely reported but important aberrant RHA variations arising from the GDA. To prevent injury during PD in patients with this type of aberrant RHA, intensive preparations using CT and/or MRI imaging before surgery and intraoperative liver Doppler ultrasonography are considered to be essential.

Resection and reconstruction of the largest abdominal vein system (the inferior vena cava, hepatic, and portal vein): a narrative review.

Background and Objective: As tumors invade major abdominal veins, surgical procedures are transformed from simple and basic to complicated and challenging. In this narrative review, we focus on what is currently known and not known regarding the technical aspects of major abdominal venous resection and its reconstruction, patency, and oncologic benefit in a cross-cutting perspective. Methods: A systematic literature search was performed in PubMed and Semantic Scholar from inception up to October 18, 2023. We reviewed 106 papers by title, abstract, and full text regarding resection or reconstruction of the inferior vena cava, hepatic vein confluence, portal vein (PV), and middle hepatic vein (MHV) tributaries in living donor liver transplantation (LDLT) in a cross-cutting perspective. Key Content and Findings: The oncologic benefit of aggressive hepatic vein resection with suitable reconstruction against adenocarcinoma remains unclear, and further studies are required to clarify this point. A superior mesenteric/PV resection is now a universal, indispensable, and effective procedure for pancreatic ductal adenocarcinoma. Although many case series using tailor-made autologous venous grafts have been reported, not only size mismatch but also additional surgical incisions and a longer operation time remain obstacles for venous reconstruction. The use of autologous alternative tissue remains only an alternative procedure because the patency rate of customized tubular conduit type to interpose or replace the resected vein is not known. Unlike arterial replacement, venous replacement using synthetic vascular grafts is still rarely reported and there are several inherent limitations except for reconstruction of tributaries of MHV in LDLT. Conclusions: Various approaches to abdominal vein resection and replacement or reconstruction are technically feasible with satisfactory results. Synthetic vascular grafts may be appropriate but have a certain rate of complications.

Two-step artificial intelligence algorithm for liver segmentation automates anatomic virtual hepatectomy.

BACKGROUND: Anatomic virtual hepatectomy with precise liver segmentation for hemilivers, sectors, or Couinaud's segments using conventional three-dimensional simulation is not automated and artificial intelligence (AI)-based algorithms have not yet been applied. METHODS: Computed tomography data of 174 living-donor candidates for liver transplantation (training data) were used for developing a new two-step AI algorithm to automate liver segmentation that was validated in another 51 donors (validation data). The Pure-AI (no human intervention) and ground truth (GT, full human intervention) data groups were compared. RESULTS: In the Pure-AI group, the median Dice coefficients of the right and left hemilivers were highly similar, 0.95 and 0.92, respectively; sectors, posterior to lateral: 0.86-0.92, and Couinaud's segments 1-8: 0.71-0.89. Labeling of the first-order branch as hemiliver, right or left portal vein perfectly matched; 92.8% of the second-order (sectors); 91.6% of third-order (segments) matched between the Pure-AI and GT data. CONCLUSIONS: The two-step AI algorithm for liver segmentation automates anatomic virtual hepatectomy. The AI-based algorithm correctly divided all hemilivers, and more than 90% of the sectors and segments.

Probe-based confocal laser endomicroscopy for real-time evaluation of colorectal liver metastasis in resected surgical specimens.

Probe-based confocal laser endomicroscopy (pCLE) enables real-time examination of tissue structure. This study investigated pCLE with or without fluorescein sodium for the intraoperative diagnosis of colorectal liver metastasis (CLM) and detection of surgical margins. Thirty-four specimens of CLM and adjacent noncancerous tissue were obtained from 21 patients and examined by pCLE between May 2017 and March 2018. Images were obtained both without and with fluorescein sodium applied to the cut surface and compared with hematoxylin and eosin-stained tissue. Fluorescence intensity (FI) was measured by luminance-analysis software. Without external fluorophores, pCLE visualized 91.2% of CLM tissues as an irregular structure with low autofluorescence and 90.5% of noncancerous liver tissues as a regular structure with high autofluorescence. The median FI was significantly lower in cancer than in benign tissue in patients without chemotherapy [70.4 (51.6-110) vs. 48.3 (39.0-59.4), p = 0.002] and with chemotherapy [67.9 (54.6-89.2) vs. 48.6 (28.8-82.1), p < 0.001]. The border was clearly visible; pCLE with fluorescein sodium clearly showed their morphologies. In summary, our study demonstrated real-time pCLE distinguished CLM and noncancerous tissue by differences in structure and FI regardless of prehepatectomy chemotherapy. Fluorescein spray facilitated clear visualization of differences in the morphology.

Artificial intelligence enhances the accuracy of portal and hepatic vein extraction in computed tomography for virtual hepatectomy.

BACKGROUND/PURPOSE: Current conventional algorithms used for 3-dimensional simulation in virtual hepatectomy still have difficulties distinguishing the portal vein (PV) and hepatic vein (HV). The accuracy of these algorithms was compared with a new deep-learning based algorithm (DLA) using artificial intelligence. METHODS: A total of 110 living liver donor candidates until 2017, and 46 donor candidates until 2019 were allocated to the training group and validation groups for the DLA, respectively. All PV or HV branches were labeled based on Couinaud's segment classification and the Brisbane 2000 Terminology by hepato-biliary surgeons. Misclassified and missing branches were compared between a conventional tracking-based algorithm (TA) and DLA in the validation group. RESULTS: The sensitivity, specificity, and Dice coefficient for the PV were 0.58, 0.98, and 0.69 using the TA; and 0.84, 0.97, and 0.90 using the DLA (P < .001, excluding specificity); and for the HV, 0.81, 087, and 0.83 using the TA; and 0.93, 0.94 and 0.94 using the DLA (P < .001 to P = .001). The DLA exhibited greater accuracy than the TA. CONCLUSION: Compared with the TA, artificial intelligence enhanced the accuracy of extraction of the PV and HVs in computed tomography.

Preoperative Predictive Features of Invasive Carcinoma Among Intraductal Papillary Mucinous Neoplasm of the Pancreas.

OBJECTIVE: Noninvasive intraductal papillary mucinous neoplasms (IPMNs) theoretically do not metastasize. The purpose of this study is to preoperatively distinguish invasive carcinomas associated with IPMN from noninvasive IPMN. METHODS: A total of 131 patients who underwent surgical resection for IPMN were retrospectively analyzed to identify the predictors of invasive carcinoma, based on the International Association of Pancreatology Consensus Guidelines. RESULTS: Of the 131 patients, 29 (22%) had invasive carcinomas and 102 (78%) had noninvasive IPMN. An enhancing mural nodule (MN) greater than or equal to 5 mm, obstructive jaundice, an abrupt change in the caliber of the pancreatic duct (PD) with distal pancreatic atrophy, and lymphadenopathy were the significant predictors of invasive carcinoma in univariate analysis. The optimal cutoff value for the size of the enhancing MN to differentiate invasive carcinoma was 13 mm. In multivariate analysis, enhancing MN greater than or equal to 13 mm, obstructive jaundice, and an abrupt change in the PD caliber were the independent predictors. When all these factors were absent, only 17% were invasive carcinomas. CONCLUSIONS: Enhancing MN greater than or equal to 13 mm, obstructive jaundice, and an abrupt change in the PD caliber were predictive factors for invasive carcinoma. Systematic lymph node dissection may be omitted when a high-risk patient has none of these factors.

Stent placement for benign portal vein stenosis following pancreaticoduodenectomy in a hybrid operating room.

Benign portal vein stenosis is a rare complication following pancreaticoduodenectomy. Because a direct surgical approach to the portal vein is difficult due to severe adhesions following pancreaticoduodenectomy, portal vein stent placement is considered a good treatment option. Herein, we report 3 cases of severe portal vein stenosis following pancreaticoduodenectomy that were treated with portal venous stent placement in a hybrid operating room, combining a conventional operating room with an angiography suite. High-resolution images on digital subtraction angiography provide better contrast and support accurate stent placement compared to using a mobile C-arm.