A multi-institutional randomized phase III study comparing minimally invasive distal pancreatectomy versus open distal pancreatectomy for pancreatic cancer; Japan Clinical Oncology Group study JCOG2202 (LAPAN study).

BACKGROUND: Minimally invasive distal pancreatectomy (MIDP), including laparoscopic and robotic distal pancreatectomy, has gained widespread acceptance over the last decade owing to its favorable short-term outcomes. However, evidence regarding its oncologic safety is insufficient. In March 2023, a randomized phase III study was launched in Japan to confirm the non-inferiority of overall survival in patients with resectable pancreatic cancer undergoing MIDP compared with that of patients undergoing open distal pancreatectomy (ODP). METHODS: This is a multi-institutional, randomized, phase III study. A total of 370 patients will be enrolled from 40 institutions within 4 years. The primary endpoint of this study is overall survival, and the secondary endpoints include relapse-free survival, proportion of patients undergoing radical resection, proportion of patients undergoing complete laparoscopic surgery, incidence of adverse surgical events, and length of postoperative hospital stay. Only a credentialed surgeon is eligible to perform both ODP and MIDP. All ODP and MIDP procedures will undergo centralized review using intraoperative photographs. The non-inferiority of MIDP to ODP in terms of overall survival will be statistically analyzed. Only if non-inferiority is confirmed will the analysis assess the superiority of MIDP over ODP. DISCUSSION: If our study demonstrates the non-inferiority of MIDP in terms of overall survival, it would validate its short-term advantages and establish its long-term clinical efficacy. TRIAL REGISTRATION: This trial is registered with the Japan Registry of Clinical Trials as jRCT 1,031,220,705 [ https://jrct.niph.go.jp/en-latest-detail/jRCT1031220705 ].

Clinical impacts of positive intraepithelial neoplasia at pancreatic transection margin in pancreatic cancer surgery.

BACKGROUND/OBJECTIVES: The outcomes of patients with intraepithelial neoplasia at the pancreatic transection margin after pancreatic cancer surgery remain unclear. We evaluated the clinical impact of pancreatic transection margin status. METHODS: This retrospective observational study included 171 patients who underwent surgery for pancreatic ductal adenocarcinoma between January 2008 and December 2019. Patients were classified into three groups: negative pancreatic transection margin (group N), positive low-grade (group L), and positive high-grade (group H) intraepithelial neoplasia. The clinicopathological findings and prognoses were analyzed for each group. RESULTS: There were 140, 14, and 9 patients in groups N, L, and H, respectively. The median age was significantly higher in group H (p = 0.035). There were no significant differences in male ratio, preoperative chemotherapy administration rate, pretreatment tumor markers, operative procedure, operative time, or blood loss. Overall survival and recurrence-free survival were not significantly different; however, the cumulative risk of recurrence in the remnant pancreas was significantly higher in group H (p = 0.018). CONCLUSIONS: Intraepithelial neoplasia at the pancreatic transection margin did not affect overall/recurrence-free survival. As patients with high-grade intraepithelial neoplasia at the pancreatic transection margin have an increased risk of recurrence in the remnant pancreas, careful postoperative follow-up is required.

Cilostazol improves the prognosis after hepatectomy in rats with sinusoidal obstruction syndrome.

BACKGROUND AND AIM: Safe radical hepatectomy is important for patients with colorectal liver metastases complicated by sinusoidal obstruction syndrome (SOS) after oxaliplatin-based chemotherapy. This study aimed to investigate the impact of preoperative administration of cilostazol (CZ), an oral selective phosphodiesterase III inhibitor, on hepatectomy in rat SOS model. MATERIAL AND METHODS: Rats were divided into NL (normal liver), SOS (monocrotaline [MCT]-treated), and SOS + CZ (MCT + CZ-treated) groups. MCT or CZ was administered orally, and a 30% partial hepatectomy was performed 48 h after MCT administration. Postoperative survival rates were evaluated (n = 9, for each). Other rats were sacrificed on postoperative days (POD) 1 and 3 and evaluated histologically, immunohistochemically, biochemically, and using transmission electron microscopy (TEM), focusing particularly on SOS findings, liver damage, and liver sinusoidal endothelial cell (LSEC) injury. RESULTS: The cumulative 10-day postoperative survival rate was significantly higher in the SOS + CZ group than in the SOS group (88.9% vs 33.3%, P = 0.001). Total SOS scores were significantly lower in the SOS + CZ group than in the SOS group on both POD 1 and 3. Serum biochemistry and immunohistochemistry showed that CZ reduced liver damage after hepatectomy. TEM revealed that LSECs were significantly preserved morphologically in the SOS + CZ group than in the SOS group on POD 1 (86.1 ± 8.2% vs 63.8 ± 9.3%, P = 0.003). CONCLUSION: Preoperative CZ administration reduced liver injury by protecting LSECs and improved the prognosis after hepatectomy in rats with SOS.

Histopathological growth pattern and vessel co-option in intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (iCCA) exhibits different blood imaging features and prognosis depending on histology. To clarity histopathological growth patterns (HGPs) and vascularization processes of iCCA, we collected 145 surgical specimens and histologically classified them into large bile duct (LBD) (20 cases), small bile duct (SBD) (54), cholangiolocarcinoma (CLC) (35), combined SBD-CLC (cSBD-CLC) (26), and ductal plate malformation (DPM) (10) (sub)types. According to the invasive pattern at the interface between tumor and adjacent background liver, HGPs were classified into desmoplastic, pushing, and replacing HGPs. Desmoplastic HGP predominated in LBD type (55.5%), while replacing HGP was common in CLC (82.9%) and cSBD-CLC (84.6%) subtypes. Desmoplastic HGP reflected angiogenesis, while replacing HGP showed vessel co-option in addition to angiogenesis. By evaluating microvessel density (MVD) using vascular markers, ELTD1 identified vessel co-option and angiogenesis, and ELTD1-positive MVD at invasive margin in replacing HGP was significantly higher than those in desmoplastic and pushing HGPs. REDD1, an angiogenesis-related marker, demonstrated preferably higher MVD in the tumor center than in other areas. iCCA (sub)types and HGPs were closely related to vessel co-option and immune-related factors (lymphatic vessels, lymphocytes, and neutrophils). In conclusion, HGPs and vascular mechanisms characterize iCCA (sub)types and vessel co-option linked to the immune microenvironment.

[Two Cases of Portal Vein Stent Placement for Portal Vein Stenosis Due to Recurrence of Pancreatic Cancer].

We report 2 cases of portal vein stent placement for malignant portal stenosis due to recurrence of pancreatic cancer with symptoms of portal hypertension. Case 1: The patient was a 68-year-old female. Five years ago, a mass was found around the aorta on a computerized tomography(CT)scan taken after a residual pancreatectomy for pancreatic cancer. It was diagnosed as lymph node recurrence and S-1 therapy was started. As further tumor enlargement led to portal vein compression, venostasis around the ascending jejunum, anemia, and black stools, a portal vein stent was placed. The portal vein blood flow was improved, the collateral vessels disappeared, and the patient no longer experienced anemia or black stool. Case 2: A 75-year-old female patient underwent a subtotal gastric-sparing pancreaticoduodenectomy and combined resection of the portal vein for pancreas head cancer. On a postoperative CT scan taken 6 months later, a mass compressing the portal vein appeared, which was diagnosed as a local recurrence. As thrombocytopenia was observed, a portal vein stent was placed before starting chemotherapy. The portal vein blood flow and the platelet count improved. Portal vein stenting is an effective procedure for malignant portal stenosis, improving portal blood flow and clinical symptoms.

Two Concepts of Hepatitis B Core-Related Antigen Assay: A Highly Sensitive and Rapid Assay or an Effective Tool for Widespread Screening.

Hepatitis B core-related antigen (HBcrAg) reflects the activity of intrahepatic covalently closed circular DNA. HBcrAg can be detected even in chronic hepatitis B patients in whom serum HBV DNA or hepatitis B surface antigen is undetectable. The HBcrAg measurement system was developed based on two concepts. One is a fully-automated and highly-sensitive HBcrAg assay (iTACT-HBcrAg) and the other is a point-of-care testing (POCT) that can be used in in resource-limited areas. iTACT-HBcrAg is an alternative to HBV DNA for monitoring HBV reactivation and predicting the development of hepatocellular carcinoma. This validated biomarker is available in routine clinical practice in Japan. Currently, international guidelines for the prevention of mother-to-child transmission recommend anti-HBV prophylaxis for pregnant women with high viral loads. However, over 95% of HBV-infected individuals live in countries where HBV DNA quantification is widely unavailable. Given this situation, a rapid and simple HBcrAg assay for POCT would be highly effective. Long-term anti-HBV therapy may have potential side effects and appropriate treatment should be provided to eligible patients. Therefore, a simple method of determining the indication for anti-HBV treatment would be ideal. This review provides up-to-date information regarding the clinical value of HBcrAg in HBV management, based on iTACT-HBcrAg or POCT.

A surgical case of anti-coagulant ileus mimicking small-bowel tumors: a case report.

BACKGROUND: Anti-coagulant ileus, characterized by intramural hematoma due to excessive anti-coagulant therapy, presents a diagnostic challenge. Although previously considered uncommon, recently, reporting cases of anti-coagulant ileus have become more frequent. Herein, we report a rare surgical case of anti-coagulant ileus mimicking small-bowel tumors. CASE PRESENTATION: A 79-year-old man was admitted to our hospital for fatigue. He had been administered warfarin for 5 months for atrial fibrillation. On admission, the patient exhibited mild epigastric tenderness. Laboratory test results revealed anemia (hemoglobin, 8.4 g/dL); unmeasurably prolonged prothrombin time (PT) with international normalized ratio (INR) > 8; and elevated soluble interleukin 2 receptor (sIL-2R) levels (849 IU/mL; normal range, 122-496 IU/mL). Abdominal plain computed tomography (CT) showed a circumferentially thickened intestinal wall at one site in the jejunum and two in the ileum. After hospitalization, bowel obstruction did not improve with conservative treatment. Suspecting small-bowel tumors such as lymphoma, the patient subsequently underwent open surgery on day 3 after admission. No obvious tumor mass was observed intra-operatively. However, only thickened and hemorrhagic segments were identified at the suspected sites. We performed partial jejunal and ileal resections of 12 and 27 cm, respectively. Histopathology confirmed submucosal congestion, edema, and hemorrhage in each area without tumor components, leading to the final diagnosis of intramural hematoma. The postoperative course was uneventful, and he was discharged on postoperative day 9. No recurrence occurred during the 5-year follow-up period. CONCLUSIONS: We encountered a surgical case of anti-coagulant ileus, which was difficult to differentiate from malignant lymphoma based on CT findings and high sIL-2R levels. The possibility of anti-coagulant ileus should always be considered in patients on long-term anticoagulation medication and bowel obstruction with high PT-INR values.

Clinicopathological features of cholangiolocarcinoma and impact of tumor heterogeneity on prognosis: A single institution retrospective study.

Cholangiolocarcinoma (CLC) is an extremely rare tumor classified as a subtype of small duct-type intrahepatic cholangiocarcinoma (iCCA). There are few detailed reports on CLC and the prognostic impact of tumor heterogeneity is not clear. Between April 2006 and June 2022, of the 774 primary liver cancer resection cases who presented at Kanazawa University Hospital, 14 patients were pathologically diagnosed with CLC through immunohistochemical analysis of their molecular and biological features. Clinicopathological features and prognoses were evaluated retrospectively. Additionally, tumor heterogeneity was assessed and tumors were classified into pure and partial types according to the CLC component proportion in a single tumor. Chronic liver disease was observed in nine patients (64.3%). All tumors were mass-forming, and pathological R0 resection was achieved in 11 patients (78.6%). Tumor heterogeneity was classified as pure in 11 (78.6%) and partial in three (21.4%) patients. The median follow-up was 59.5 months (12-114 months). There was no difference in the 5-year disease-specific survival rates between the pure and partial (90.0% vs. 100.0%; P=0.200) types, but rates were significantly higher in the R0 resection group compared with those in the R1 resection group (100.0% vs. 50.0%; P=0.025). In conclusion, these results suggest that it is important for CLC patients to achieve curative resection, and CLC may have a good prognosis regardless of the proportion of CLC components in a single tumor.

Impact of aging on peribiliary glands in ischemia-reperfusion injury.

BACKGROUND: The detailed mechanisms underlying the development of ischemia-type biliary lesions (ITBLs) in aged donor grafts remain unclear. In the present study we aimed to investigate the impact of aging on the response of the peribiliary gland (PBG) to ischemia-reperfusion injury (IRI) and its temporal changes. METHODS: Experiments were performed using a 90-min partial warm liver ischemia model in male Wistar rats of two age groups: young (7-8 weeks old) and old (52-60 weeks old). Liver tissues were obtained 24, 72, and 168 h after IRI. Histopathological and immunohistochemical assessments of the perihilar bile duct (PHBD), including the PBG, distal to the clip-clamped site were performed. RESULTS: Young rats showed little change in the bile duct tissues after IRI. However, old rats showed an increased PBG volume in the PHBD and marked PBG cell proliferation 24 h after IRI. Bile duct wall thickening with narrowing of the lumen peaked 72 h after IRI. Mucus production and oxidative stress in the PBG were significantly higher in old than in young rats after IRI. These findings showed a trend toward improvement 168 h after IRI. CONCLUSION: Age-dependent differences in the response of the PBG to IRI may be related to differences in ITBL frequency.

Long-term outcomes after spleen-preserving distal pancreatectomy with splenic vessels preservation or resection: A nationwide survey of the Japanese Society of Pancreatic Surgery.

BACKGROUND: Spleen preserving distal pancreatectomy is achieved by either splenic vessel resection or splenic vessel preservation. However, the long-term outcomes of spleen-preserving distal pancreatectomy with splenic vessel resection and spleen-preserving distal pancreatectomy with splenic vessel preservation are not well known. This study aimed to evaluate the long-term outcomes of spleen-preserving distal pancreatectomy with splenic vessel resection and spleen-preserving distal pancreatectomy with splenic vessel preservation. METHODS: The study included a total of 335 patients who underwent spleen-preserving distal pancreatectomy during the study period and underwent computed tomography or magnetic resonance imaging 3 and 5 years after surgery in the Japan Society of Pancreatic Surgery member institutions. We evaluated the diameter of the perigastric and gastric submucosal veins, patency of the splenic vessels, and splenic infarction. Preoperative backgrounds and short- and long-term outcomes were compared between the 2 groups. RESULTS: Forty-four (13.1%) and 291 (86.9%) patients underwent spleen-preserving distal pancreatectomy with splenic vessel resection and spleen-preserving distal pancreatectomy with splenic vessel preservation, respectively. There were no significant differences in short-term outcomes between the 2 groups. Regarding long-term outcomes, the prevalence of perigastric varices was higher (P = .006), and platelet count was lower (P = .037) in the spleen-preserving distal pancreatectomy with splenic vessel resection group. However, other complications, such as gastric submucosal varices, postoperative splenic infarction, gastrointestinal bleeding, reoperation, postoperative splenectomy, and other hematologic parameters, were not significantly different between the 2 groups 5 years after surgery. In terms of the patency of splenic vessels in spleen preserving distal pancreatectomy with splenic vessel preservation cases, partial or complete occlusion of the splenic artery and vein was observed 5 years after surgery in 19 (6.5%) and 55 (18.9%) patients, respectively. CONCLUSION: Perigastric varices and thrombocytopenia were observed more in spleen-preserving distal pancreatectomy with splenic vessel resection, yet late clinical events such as gastrointestinal bleeding and splenic infarction are acceptable for spleen-preserving distal pancreatectomy with splenic vessel preservation.

Morphology of the Dorsal Pancreatic Artery and Its Oncological Significance in Pancreatic Cancer.

OBJECTIVES: Although the dorsal pancreatic artery (DPA) is an important artery that supplies the pancreas, its morphology has not been sufficiently studied. We investigated the morphology of the DPA and the progression of pancreatic cancer along this vessel. MATERIALS AND METHODS: Overall, 142 patients with pancreatic cancer who underwent surgical resection at Kanazawa University Hospital between 2004 and 2015 were enrolled. We examined the morphology of the DPA using preoperative computed tomography and cancer progression along the DPA using resected specimens. We investigated the anatomical structures surrounding the DPA through cadaveric examination. RESULTS: The analysis of computed tomography images revealed the presence of the DPA in 141 patients. In typical cases, the DPA divides into a head and a body branch. Histopathological examination revealed cancer progression along the DPA in 32 patients. Cancer progression along the DPA was identified as a factor associated with a poor prognosis in pancreatic head or body cancer. Cadaveric examination showed the presence of abundant nerve and lymphatic tissues along the DPA. CONCLUSIONS: It is important to remove the soft tissue surrounding the DPA during surgery for pancreatic head or body cancer because it may serve as an important route for cancer progression.

Predictors of portal vein thrombosis after simultaneous hepatectomy and splenectomy: A single-center retrospective study.

BACKGROUND: Although postoperative portal vein thrombosis (PVT) is a frequent complication of splenectomy, few studies have examined PVT after simultaneous hepatectomy and splenectomy (HS). The aim of this study was to clarify the risk factors for and characteristics of PVT after HS. METHODS: This retrospective observational study included 102 patients, including 76 with liver cirrhosis (LC) and 26 without, who underwent HS between April 2004 and April 2021. The incidence and location of postoperative PVT detected on contrast-enhanced CT 1 week after surgery were analyzed. In addition, pre- and intraoperative parameters were compared between patients with postoperative PVT and those without in order to determine risk factors for PVT after HS. RESULTS: Among the 102 patients, 29 (28.4 %), including 32.9 % with LC and 15.4 % without LC, developed PVT after surgery. Among the 29 patients with PVT, 21 (72.4 %), 4 (13.8 %), and 4 (13.8 %) developed thrombus in the intrahepatic portal vein only, extrahepatic portal vein only, and both the extra- and intrahepatic portal veins, respectively. Multivariable analysis showed that preoperative splenic vein dilatation was an independent risk factor for PVT after HS (odds ratio: 1.53, 95 % confidence interval: 1.156-2.026, P = 0.003). CONCLUSION: Our results suggest that splenic vein dilatation is an independent risk factor for PVT after simultaneous HS, and that PVT after HS occurs more frequently in the intrahepatic portal vein. After HS for cases with dilated splenic veins, we should pay particular attention to the PVT development in the intrahepatic portal vein regardless of the type of liver resection.