Explainable artificial intelligence prediction-based model in laparoscopic liver surgery for segments 7 and 8: an international multicenter study.

BACKGROUND: Artificial intelligence (AI) is becoming more useful as a decision-making and outcomes predictor tool. We have developed AI models to predict surgical complexity and the postoperative course in laparoscopic liver surgery for segments 7 and 8. METHODS: We included patients with lesions located in segments 7 and 8 operated by minimally invasive liver surgery from an international multi-institutional database. We have employed AI models to predict surgical complexity and postoperative outcomes. Furthermore, we have applied SHapley Additive exPlanations (SHAP) to make the AI models interpretable. Finally, we analyzed the surgeries not converted to open versus those converted to open. RESULTS: Overall, 585 patients and 22 variables were included. Multi-layer Perceptron (MLP) showed the highest performance for predicting surgery complexity and Random Forest (RF) for predicting postoperative outcomes. SHAP detected that MLP and RF gave the highest relevance to the variables "resection type" and "largest tumor size" for predicting surgery complexity and postoperative outcomes. In addition, we explored between surgeries converted to open and non-converted, finding statistically significant differences in the variables "tumor location," "blood loss," "complications," and "operation time." CONCLUSION: We have observed how the application of SHAP allows us to understand the predictions of AI models in surgical complexity and the postoperative outcomes of laparoscopic liver surgery in segments 7 and 8.

Prognostic impact of the distance from the root of splenic artery to tumor in the patients with pancreatic body or tail cancer.

BACKGROUND: The impact of the distance from the root of splenic artery to tumor (DST) on the prognosis and optimal surgical procedures in the patients with pancreatic body/tail cancer has been unclear. METHODS: We retrospectively analyzed 94 patients who underwent distal pancreatectomy (DP) and 17 patients who underwent DP with celiac axis resection (DP-CAR) between 2008 and 2018. RESULTS: The 111 patients were assigned by DST length (in mm) as DST = 0: n = 14, 0

Phase I study of neoadjuvant S-1 plus cisplatin with concurrent radiation for biliary tract cancer (Tokyo Study Group for Biliary Cancer: TOSBIC02).

Aim: Neoadjuvant chemoradiotherapy may improve survival in patients with advanced cholangiocarcinoma. This Phase I study aimed to determine the recommended dose of neoadjuvant chemoradiotherapy and decide whether to move to a Phase II study. Methods: Patients diagnosed with resectable stage II-IVa cholangiocarcinoma were administered cisplatin (40 [level 0], 50 [level 1 as starting dose], or 60 [level 2] mg/m2), 80 mg/m2 of S-1, and 50.4 Gy of external beam radiation. The recommended dose was defined as a dose one-step lower than the maximum-tolerated dose, which was defined when dose-limiting toxicity was observed in three or more of the six patients. Results: Twelve patients were eligible from November 2012 to May 2016. Ten patients had perihilar cholangiocarcinoma and two patients had distal cholangiocarcinoma. Dose-limiting toxicity was observed in one of the first six patients at level 1 and two of the next six patients at level 2; thus, the maximum-tolerated dose was not determined even at level 2 and the recommended dose was determined as level 2. Four patients had partial response, four patients had stable disease, and two patients had progression of disease because of liver metastases. Finally, nine patients underwent radical surgery and seven cases achieved R0 resection. However, five cases suffered biliary leakage and one suffered intrahospital death due to rupture of the hepatic artery. Conclusion: We determined the recommended dose of neoadjuvant chemoradiotherapy for resectable cholangiocarcinoma. However, we terminated the trial due to a high incidence of morbidity and unexpected mortality.

Short- and long-term outcomes of laparoscopic radical gallbladder resection for gallbladder carcinoma: A multi-institutional retrospective study in Japan.

BACKGROUND/PURPOSE: Laparoscopic resection of gallbladder carcinomas remains controversial. This study aimed to evaluate the surgical and oncological outcomes of laparoscopic procedures for suspected gallbladder carcinoma (GBC). METHODS: In this retrospective study, data regarding suspected GBC treated with laparoscopic radical cholecystectomy before 2020 in Japan, was included. Patient characteristics, surgical procedure details, surgical outcomes, and long-term outcomes were analyzed. RESULTS: Data of 129 patients with suspected GBC who underwent laparoscopic radical cholecystectomy were retrospectively collected from 11 institutions in Japan. Among them, 82 patients with pathological GBC were included in the study. Laparoscopic gallbladder bed resection was performed in 114 patients and laparoscopic resection of segments IVb and V was performed in 15 patients. The median operation time was 269 min (range: 83-725 min), and the median intraoperative blood loss was 30 mL (range: 0-950 mL). The conversion and postoperative complication rates were 8% and 2%, respectively. During the follow-up period, the 5-year overall survival rate was 79% and the 5-year disease-free survival rate was 87%. Recurrence was detected in the liver, lymph nodes, and other local tissues. CONCLUSION: Laparoscopic radical cholecystectomy is a treatment option with potential favorable outcomes in selected patients with suspected GBC.

Surgical and Oncological Outcomes of Salvage Hepatectomy for Locally Recurrent Hepatocellular Carcinoma after Locoregional Therapy: A Single-Institution Experience.

Surgical and oncological outcomes of hepatectomy for recurrent hepatocellular carcinoma (HCC) after locoregional therapy, including locally recurrent HCC (LR-HCC), were examined. Among 273 consecutive patients who underwent hepatectomy for HCC, 102 with recurrent HCC were included and retrospectively reviewed. There were 35 patients with recurrent HCC after primary hepatectomy and 67 with recurrent HCC after locoregional therapies. Pathologic review revealed 30 patients with LR-HCC. Background liver function was significantly worse in patients with recurrent HCC after locoregional therapy (p = 0.002). AFP (p = 0.031) and AFP-L3 (p = 0.033) serum levels were significantly higher in patients with LR-HCC. Perioperative morbidities were significantly more frequently observed with recurrent HCC after locoregional therapies (p = 0.048). Long-term outcomes of recurrent HCC after locoregional therapies were worse than those after hepatectomy, though there was no prognostic difference according to the recurrence patterns after locoregional therapies. Multivariate analyses showed that prognostic factors for resected recurrent HCC were previous locoregional therapy (hazard ratio [HR] 2.0; p = 0.005), multiple HCCs (HR 2.8; p < 0.001), and portal venous invasion (HR 2.3; p = 0.001). LR-HCC was not a prognostic factor. In conclusion, salvage hepatectomy for LR-HCC showed worse surgical outcomes but a favorable prognosis.

The impact of preclinical clerkship in general surgery on medical students' attitude to a surgical career.

PURPOSE: With the advent of a new program for postgraduate medical students in 2004, the number of applicants choosing surgical careers in Japan has been declining. We conducted this study to evaluate the impact of preclinical clerkship and how it affects students' attitudes toward a surgical career. METHODS: The subjects of our study were fifth-year medical students who participated in a clinical clerkship in general surgery in our department between April 2021 and March 2022. We conducted pre- and post-preclinical clerkship surveys to assess the perceived image of surgeons and the impact of clerkship on surgical career interest. RESULTS: Among 132 medical students (77 men and 55 women) who rotated through preclinical clerkship in our department, 125 participated in the survey and 66% expressed interest in a surgical career. In the post-clerkship survey, an increased interest in a surgical career was expressed by 79% of the students; notably, including those who initially expressed interest. Approximately 77% of students were satisfied with the practical skill training they received. CONCLUSION: Engaging medical students early in surgical experience through a preclinical clerkship for general surgery appears to promote their interest in a surgical career.

Clinical implications of lymphadenectomy for invasive ductal carcinoma of the body or tail of the pancreas.

Aim: The appropriate extent of lymphadenectomy for pancreatic cancer of the body/tail has not been standardized worldwide. The present study evaluated the optimal extent of harvesting lymph nodes. Methods: Patients who underwent distal pancreatectomy for invasive ductal carcinoma of the pancreas between 2007 and 2018 were retrospectively reviewed. Patients were subclassified into three groups depending on the tumor location: pancreatic body (Pb), proximal pancreatic tail (Ptp), and distal pancreatic tail (Ptd). The pancreatic tail was further divided into even sections of Ptp and Ptd. Patterns of lymph node metastasis and the impact of lymph node metastasis on the prognosis were examined. Results: A total of 120 patients were evaluated. Fifty-eight patients had a tumor in the Pb, 38 in the Ptp, and 24 in the Ptd. No patients with a Ptd tumor had metastasis beyond the peripancreatic and splenic hilar lymph nodes (LN-PSH). All patients with metastasis to the lymph nodes along the common hepatic artery (LN-CHA) or along the left lateral superior mesenteric artery (LN-SMA) also had metastasis to the LN-PSH. Recurrence after surgery occurred significantly earlier in this population. In a multivariate analysis, metastasis to the LN-CHA or LN-SMA (hazard ratio [HR] 3.3; P = .04) was an independent risk factor for overall survival. Furthermore, high levels of preoperative serum CA19-9 (HR 10.9; P = .013) were a predictive factor for metastasis to the LN-CHA or LN-SMA. Conclusions: Metastasis to the LN-CHA or LN-SMA was rare but a significant prognostic factor in patients with pancreatic body/tail cancer.

A prospective feasibility study of one-year administration of adjuvant S-1 therapy for resected biliary tract cancer in a multi-institutional trial (Tokyo Study Group for Biliary Cancer: TOSBIC01).

BACKGROUND: Although surgery is the definitive curative treatment for biliary tract cancer (BTC), outcomes after surgery alone have not been satisfactory. Adjuvant therapy with S-1 may improve survival in patients with BTC. This study examined the safety and efficacy of 1 year adjuvant S-1 therapy for BTC in a multi-institutional trial. METHODS: The inclusion criteria were as follows: histologically proven BTC, Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1, R0 or R1 surgery performed, cancer classified as Stage IB to III. Within 10 weeks post-surgery, a 42-day cycle of treatment with S-1 (80 mg/m2/day orally twice daily on days 1-28 of each cycle) was initiated and continued up to 1 year post surgery. The primary endpoint was adjuvant therapy completion rate. The secondary endpoints were toxicities, disease-free survival (DFS), and overall survival (OS). RESULTS: Forty-six patients met the inclusion criteria of whom 19 had extrahepatic cholangiocarcinoma, 10 had gallbladder carcinoma, 9 had ampullary carcinoma, and 8 had intrahepatic cholangiocarcinoma. Overall, 25 patients completed adjuvant chemotherapy, with a 54.3% completion rate while the completion rate without recurrence during the 1 year administration was 62.5%. Seven patients (15%) experienced adverse events (grade 3/4). The median number of courses administered was 7.5. Thirteen patients needed dose reduction or temporary therapy withdrawal. OS and DFS rates at 1/2 years were 91.2/80.0% and 84.3/77.2%, respectively. Among patients who were administered more than 3 courses of S-1, only one patient discontinued because of adverse events. CONCLUSIONS: One-year administration of adjuvant S-1 therapy for resected BTC was feasible and may be a promising treatment for those with resected BTC. Now, a randomized trial to determine the optimal duration of S-1 is ongoing. TRIAL REGISTRATION: UMIN-CTR, UMIN000009029. Registered 5 October 2012-Retrospectively registered, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000009347.

Significance of a preoperative tumor marker gradient for predicting microvascular invasion in cases of hepatocellular carcinoma.

Although vascular invasion is an important factor in the progression and treatment of hepatocellular carcinoma (HCC), it remains difficult to determine, on the basis of preoperative imaging alone, whether vascular invasion, especially microvascular invasion, has occurred. The current retrospective study enrolled 292 patients who, between 2004 and 2014, underwent curative hepatectomy as an initial treatment for HCC. The patients were divided between those with (n=70) and those without (n=222) microvascular invasion. Whether tumor-marker-based prediction of microvascular invasion was possible was assessed by comparing the preoperative serum α-fetoprotein (AFP) and prothrombin induced by vitamin K absence or antagonist-II concentrations between two groups of patients. The AFP concentration was significantly higher in patients with microvascular invasion compared with patients without microvascular invasion (P=0.0019). Stepwise logistic regression analysis demonstrated the AFP concentration and the logarithmic conversion ratio of the AFP gradient (log AFP grad) to be useful (P=0.0019; 0.0424) for predicting microvascular invasion. The serum AFP concentration and log AFP grad appear to be clinically useful in predicting microvascular invasion in patients with HCC.

Laparoscopic repeat liver resection after open liver resection: A comparative study from a single-centre.

BACKGROUND: Technological innovations have made it possible to use laparoscopic liver resection in cases with pre-existing adhesions or cicatricial changes. However, laparoscopic repeat liver resection (LRLR) still represents a challenge for surgeons, especially in case of previous open liver surgery. This study evaluated the outcomes of LRLR after open liver resection (OLR) in cases of recurrent liver cancer. MATERIALS AND METHODS: A total of 62 patients who underwent laparoscopic minor liver resection at our institution between September 2012 and September 2016 were retrospectively divided into an LRLR group (n = 13) and a laparoscopic primary liver resection group (LPLR; n = 49). The two groups were compared in terms of patient demographics, surgical procedures and short-term outcomes. Recurrence-free survival (RFS) and overall survival (OS) were compared for patients with hepatocellular carcinoma (HCC) or colorectal liver metastases (CRLMs). RESULTS: There was a significant intergroup difference in the hepatitis virus background, although the two groups' primary histology and pre-operative liver function were comparable. The two groups had statistically similar values for extent of resection, operative time, estimated blood loss, transfusion requirement, conversion to laparotomy, post-operative complications, surgical margins, time to oral intake and hospital stay. No significant differences were detected when we stratified the cases according to low and intermediate difficulty. Furthermore, there were no intergroup differences in RFS or OS in the two groups for patients with HCC and CRLM. CONCLUSIONS: The findings suggest that minor LRLR after OLR is safe and comparable with minor LPLR in the present study.

Activation of extracellular signal-regulated kinase is associated with hepatocellular carcinoma with aggressive phenotypes.

AIM: Sorafenib inhibits multiple kinase signaling pathways, including the rat sarcoma virus (Ras)/rapidly accelerated fibrosarcoma (Raf)/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway, and is a promising therapy for hepatocellular carcinoma (HCC). However, the role of ERK activation in HCC remains unclear. This study was designed to investigate the potential link between ERK activation and aggressive HCC phenotypes. METHODS: We evaluated nuclear ERK expression by immunohistochemistry in 154 resected HCC nodules from 136 patients. We then investigated the associations of ERK expression with the clinicopathological characteristics of HCC, c-MET expression, and the molecular subclass biomarkers Ki-67, keratin 19 (KRT19, CK19, or K19), and sal-like protein 4. Multivariate Cox regression analysis was carried out to determine independent prognostic factors for overall survival and recurrence-free survival. The effects of ERK activation by hepatocyte growth factor (HGF) on eight HCC cell lines were further examined. RESULTS: High-level nuclear expression of ERK was observed in 20 (13%) of 154 nodules and was significantly associated with higher serum alpha-fetoprotein levels (P = 0.034), poorer differentiation (P = 0.003), a higher Ki-67 index (P < 0.001), high-level expression of c-MET (P = 0.008), KRT19 (P = 0.002), or sal-like protein 4 (P < 0.001), and shorter overall survival (multivariate hazard ratio 3.448; P = 0.028) and recurrence-free survival (multivariate hazard ratio 2.755; P = 0.004). HCC cells treated with hepatocyte growth factor showed enhanced cell proliferation together with ERK activation and upregulated KRT19 expression, both of which were inhibited by sorafenib. CONCLUSIONS: High-level ERK activation is associated with a KRT19-positive highly proliferative subtype of HCC with a dismal prognosis. These findings support the key role of the hepatocyte growth factor/c-MET/ERK axis in HCC progression.

Methicillin-resistant Staphylococcus aureus carriers are vulnerable to bloodstream infection after living donor liver transplantation.

BACKGROUND: Bloodstream infection (BSI) is a life-threatening complication after living donor liver transplantation (LDLT). We aimed to explore the incidence and predisposing factors of BSI at our institution. METHODS: We conducted a retrospective cohort analysis on all consecutive adults with BSI within 6 months after LDLT performed between 2005 and 2016. For antimicrobial prophylaxis, ampicillin/sulbactam, cefotaxime, and micafungin were administered. From 2011, methicillin-resistant Staphylococcus aureus (MRSA) carriers were decolonized using mupirocin ointment and chlorhexidine gluconate soap. Risk factors for BSI were identified by uni- and multivariate logistic regression. RESULTS: Of a total of 106 LDLTs, 42 recipients (40%) suffered BSI. The BSI group demonstrated significantly higher in-hospital mortality rates compared with the non-BSI group (24% vs. 7%, P = .01). We identified MRSA carrier (odds ratio [OR], 19.1; P < .001), ABO incompatibility (OR, 2.9; P = .03), and estimated glomerular filtration rate <30 mL/min/1.73m2 (OR, 15.8; P = .02) as independent risk factors for BSI. Decolonization treatment for MRSA carriers did not reduce the incidence of all-cause BSI but reduced the frequency of BSI caused by MRSA. CONCLUSION: To our knowledge, for the first time, MRSA carriers were revealed to be highly vulnerable to BSI after LDLT.

ADAM12 and ADAM17 are essential molecules for hypoxia-induced impairment of neural vascular barrier function.

Neural vascular barrier is essential for the life of multicellular organisms, and its impairment by tissue hypoxia is known to be a central of pathophysiology accelerating the progression of various intractable neural diseases. Therefore, the molecules involved in hypoxia-induced impairment of vascular barrier can be the targets to establish new therapies for intractable diseases. Here, we demonstrate that a disintegrin and metalloproteinases (ADAMs) 12 and 17 expressed in endothelial cells are the molecules responsible for the impairment of neural vascular barrier by hypoxia. Brain microvascular endothelial cells in vitro lost their barrier properties immediately after hypoxic stimulation through diminished localization of claudin-5, a tight junction molecule, on cell membranes. Hypoxic disappearance of claudin-5 from cell membranes and the consequent loss of barrier properties were completely suppressed by inhibition of the metalloproteinase activity which was found to be attributed to ADAM12 and ADAM17. Inhibition of either ADAM12 or ADAM17 was sufficient to rescue the in vivo neural vasculature under hypoxia from the loss of barrier function. This is the first report to specify the molecules which are responsible for hypoxia-induced impairment of neural vascular barrier and furthermore can be the targets of new therapeutic strategies for intractable neural diseases.

Novel strategy for laparoscopic treatment of pT2 gallbladder carcinoma.

BACKGROUND: This study evaluated our new strategy for treating suspected T2 gallbladder carcinoma (GBC) using a laparoscopic approach. METHODS: We examined 19 patients with suspected T2 GBC who were treated laparoscopically (LS group) between December 2007 and December 2013; these patients were compared with 14 patients who underwent open surgery (OS group). Laparoscopic staging was initially performed to exclude factors making the patients ineligible for curative resection. Intraoperative pathological examination of the surgical margin of the cystic duct was performed prior to laparoscopic gallbladder bed resection, and pathological examination was again performed to confirm the presence of carcinoma and the depth of tumor invasion. Surgery was completed when the pathological findings indicated that the patient was cancer free. Lymph node dissection was performed according to the depth of tumor invasion. RESULTS: None of the patients required conversion to laparotomy. For three patients with benign lesions, only gallbladder bed resection was required. Additional regional lymph node dissection was performed in 16 patients in the LS group. The mean operative time (309 vs. 324 min, p = 0.755) and mean number of dissected lymph nodes (12.6 vs. 10.2, p = 0.361) were not significantly different between the LS and OS groups. The intraoperative blood loss was significantly lower (104 vs. 584 mL, p = 0.002) and the postoperative hospital stay was significantly shorter (9.1 vs. 21.6 days, p = 0.002) for LS patients than for those in the OS group. In the LS group, one patient developed postoperative pneumonia, but all patients survived without recurrence after a mean follow-up of 37 months. CONCLUSION: Our strategy for suspected T2 gallbladder GBC is safe and useful, avoids unnecessary procedures, and is associated with similar oncologic outcomes as the open method.

Endoscopic biliary drainage as a bridging procedure to single-stage surgery for perforated choledochal cyst: a case report and review of the literature.

Choledochal cyst (CC)-a congenital anomaly of the bile duct-is rare. We report a 28-year-old woman complaining of epigastralgia who was transferred to our hospital. Physical examination revealed severe tenderness to abdominal palpation without symptoms of diffuse peritonitis. Urgent contrast-enhanced abdominal computed tomography indicated the dilated common bile duct (CBD) was perforated, with a presumed diagnosis of perforated CC. Endoscopic external biliary drainage was performed immediately as a bridging procedure to the definitive surgery. Additional evaluations confirmed a type IVa CC, according to Todani's classification, but no signs of malignancy. Twenty-two days after biliary drainage, laparotomy was performed. A large cystic mass was found in the CBD with a perforated scar on the right-side wall. Because inflammation around the pancreas head was too severe to perform cyst excision safely, the patient underwent subtotal stomach-preserving pancreatoduodenectomy. The postoperative course was uneventful, and the patient was discharged on the 29th postoperative day. Pathologic examination of a specimen showed no malignancy, and the patient has remained well during the 3-year follow-up. Our experience with this case suggests that definitive single-stage surgery for perforated CC in an adult can be performed safely owing to external biliary drainage as a bridging procedure, if manifestation of diffuse peritonitis is not evident.

[Treatment of early rectal carcinoma by transanal resection-a case report].

A 55-year-old female was admitted to Ogikubo Hospital for severe anemia and prolapse of a tumor from the anus, which had developed over 2 years. Rectal examination revealed a giant soft tumor. Endoscopic study revealed a lobulated giant tumor with a granular surface. Gastrografin-enema study showed a giant tumor, which was full of the rectum. Pathological examination showed a well differentiated carcinoma. No other prominent metastatic lesions were demonstrated. The transanal diagnostic resection of rectal cancer was performed in October 2010. This correct diagnosis showed both well differentiated adenocarcinoma and intramucosal carcinoma. We therefore recommend that a tumor of the lower rectum should undergo a diagnostic excision by means of either a local excision, ESD or TEM.