Machine learning approach to predict postpancreatectomy hemorrhage following pancreaticoduodenectomy: a retrospective study.

BACKGROUND: Postpancreatectomy hemorrhage (PPH) is a rare yet dreaded complication following pancreaticoduodenectomy (PD). This retrospective study aimed to explore a machine learning (ML) model for predicting PPH in PD patients. METHODS: A total of 284 patients who underwent open PD at our institute were included in the analysis. To address the issue of imbalanced data, the adaptive synthetic sampling (ADASYN) technique was employed. The best-performing ML model was selected using the PyCaret library in Python and evaluated based on recall, precision, and F1 score metrics. In addition to assessing the model's performance on the test data, bootstrap validation (n = 1000) with the original dataset was conducted. RESULTS: PPH occurred in 11 patients (3.9%), with a median onset time of 22 days postoperatively. These minority cases were oversampled to 85 using ADASYN. The extra trees classifier demonstrated superior performance with recall, precision, and F1 score of 0.967, 0.914, and 0.937, respectively. Both validation using the test data and bootstrap resampling consistently demonstrated recall, precision, and F1 score exceeding 0.9. The model identified the peak value of C-reactive protein during the first 7 postoperative days as the most significant feature, followed by the preoperative neutrophil-to-lymphocyte ratio. CONCLUSIONS: This study highlights the potential of the ML approach to predict PPH occurrence following PD. Vigilance and early interventions guided by such model predictions could positively impact outcomes for high-risk patients.

High hand grip strength is a significant risk factor and a useful predictor of postoperative pancreatic fistula following pancreaticoduodenectomy.

BACKGROUND: Postoperative pancreatic fistula (POPF) is one of the most critical complications of pancreaticoduodenectomy (PD). Studies on predictive factors for POPF that can be identified preoperatively are limited. Recent reports have highlighted the association between the preoperative nutritional status, including sarcopenia, and postoperative complications. We examined preoperative risk factors for POPF after PD, focusing on nutritional indicators. METHODS: A total of 153 consecutive patients who underwent PD at our institution were enrolled in this study. Preoperative nutritional parameters, including hand grip strength (HGS) and skeletal muscle mass as components of sarcopenia, were incorporated into the analysis. POPFs were categorized according to the International Study Group of Pancreatic Fistula (ISGPF) definition as biochemical (grade A) or clinically relevant (CR-POPF; grades B and C). RESULTS: Thirty-seven of the 153 patients (24.1%) fulfilled the ISGPF definition of CR-POPF postoperatively. In the univariate analysis, the incidence of CR-POPF was associated with male sex, non-pancreatic tumor diseases, a high body mass index, a high HGS and a high skeletal muscle mass index. In the multivariate analysis, non-pancreatic tumor diseases and an HGS ≥23.0 kg were selected as independent risk factors for CR-POPF (P <0.05). CONCLUSIONS: A high HGS, a screening tool for sarcopenia, was a risk factor for CR-POPF. It can accurately serve as a useful predictor of POPF risk in patients undergoing PD. These results highlight the potential of sarcopenia to reduce the incidence of POPF and highlight the need to clarify the mechanism of POPF occurrence.

Prognostic value of geriatric nutritional risk index for patients with biliary tract cancer undergoing surgical resection - a single-institution retrospective cohort study.

Introduction: The geriatric nutritional risk index (GNRI) is an index of nutritional status associated with clinical outcomes in various cancers; however, its prognostic value in biliary tract cancer (BTC) remains to be elucidated. This retrospective study aimed to investigate the association between preoperative GNRI and long-term prognosis of patients with BTC undergoing surgical resection. Material and methods: A total of 213 patients were included. The relationships between GNRI and clinicopathological variables, including inflammatory markers such as C-reactive protein (CRP) and neutrophil-to-lympho-cyte ratio, were analysed. The impact of GNRI on overall survival (OS) and relapse-free survival (RFS) was investigated by Kaplan-Meier curves and Cox proportional hazards models. Results: Applying a GNRI cut-off of 98, the low-GNRI group comprised 135 patients (63%). The low-GNRI group had elevated carbohydrate antigen 19-9 and CRP levels, high rates of preoperative biliary stenting, lymph node metastases, and perineural invasion, and a lower rate of R0 resection than the high-GNRI group. Both OS and RFS in the low-GNRI group were significantly lower. In multivariate analysis, low GNRI was a significant predictor of poor OS (hazard ratio [HR], 1.731; 95% CI: 1.111-2.696; p = 0.015) and RFS (HR, 1.900; 95% CI: 1.231-2.931; p = 0.004), independently of inflammatory and tumour markers, as well as of pathological features. Conclusions: Preoperative GNRI may be an easily accessible predictor of poor prognosis in patients with BTC undergoing surgical resection.

[Two Cases of Elderly Patients with Giant Intrahepatic Cholangiocarcinoma Treated with Multidisciplinary Therapy including Ablation Therapy].

Case 1 consisted of an 86-year-old male diagnosed with intrahepatic cholangiocarcinoma(ICC), approximately 11 cm in diameter, at segment S7/8 of the liver. A total of 4 percutaneous radiofrequency ablations(PRFA)and 3 hepatic arterial infusion chemotherapies(HAIC)of 5-FU were performed. He died after developing lung metastases 27 months after the initial treatment. Case 2 was an 85-year-old female diagnosed with ICC, 8 cm in diameter, at the posterior segment of the liver, with lymph node metastasis. She underwent HAIC of 5-FU and S-1 as well as gemcitabine-based systemic chemotherapy. The main tumor developed 10 months after the initial treatment, and PRFAs were subsequently performed twice for the main lesion. Although the tumor markers gradually decreased, she died of jaundice 33 months after the initial treatment. As one of the multidisciplinary therapies for the giant ICC, ablation therapy may be safe and effective in elderly patients.

[Clinical Study of Peritoneovenous Shunt for Patients with Refractory Ascites Accompanied with Hepatocellular Carcinoma].

BACKGROUND: Hepatic ascites may cause a variety of symptoms and may progress deterioration of quality of life. Peritoneovenous shunt(PV shunt)is technically feasible and useful for the treating of refractory ascites, but sometimes it can be associated with fatal complications. This retrospective study aimed to investigate the effect of PV shunt for patients with refractory ascites, including hepatocellular carcinoma(HCC)patients. SUBJECTS: Between January 2010 and December 2021, we retrospectively analyzed 54 consecutive patients(including 35 HCC patients)with refractory ascites who underwent PV shunt at our institute. RESULTS: Body weight loss after surgery was observed in 39 of the 54 cases, and eGFR improved in 34 cases. There were 17(31.5%)in-hospital deaths. Cases with present of portal vein tumor thrombus, Child-Pugh classification C, ALBI score≥-1.12, or serum total bilirubin≥1.7 mg/dL were significantly higher in hospital-death group than in the discharged from the hospital group. CONCLUSIONS: PV shunt for HCC patients with refractory ascites may be effective for improvement of renal function and symptoms. However, indications for PV shunt should be carefully considered for high-risk patients with adequate preoperative evaluation.

[A Case of Long-Term Survival with S-1/Cisplatin for Liver Hilum Lymph Node Metastasis of Anal Canal Squamous Cell Carcinoma after Chemoradiotherapy].

A 70-year-old woman was admitted to a local hospital because of anal pain during defecation. Anoscopy revealed an anal mass lesion, and the patient was referred to our hospital. Colonoscopy revealed an anal canal tumor with ulceration, and biopsy showed squamous cell carcinoma. The patient was treated with chemoradiotherapy(chemotherapy with capecitabine plus mitomycin C and 54 Gy radiation in the anal region)and achieved complete response. However, metastatic recurrence was detected in a lymph node in the hepatic hilar region. We administered an S-1/CDDP combination chemotherapy (5 courses). For 3 years and 5 months since the initial treatment, the patient survived with no signs of recurrence. We report a rare case of long-term survival with S-1/CDDP for distant metastasis of anal canal squamous cell carcinoma after chemoradiotherapy.

[Clinical Efficacy of Recombinant Human Thrombomodulin for Surgical Patients with Disseminated Intravascular Coagulation Associated with Oncologic Emergency].

AIM: We evaluated the clinical efficacy of recombinant human thrombomodulin(rTM)for surgical patients with disseminated intravascular coagulation syndrome(DIC)associated with an oncologic emergency(OE). SUBJECTS AND METHODS: Thirteen patients who underwent surgery for OE complicated with DIC and were treated with rTM in our institution were evaluated. We retrospectively analyzed the clinical changes of parameters in white blood cell count(WBC), platelet count, CRP, PT-INR and DIC scores after the rTM treatment. RESULTS: The average length of the days using rTM was 4.7 for 12 patients, excluding one who died within 30 days after surgery. Nine of 12 patients(75%)had DIC scores of less than 3 after the rTM treatment. WBC tended to decrease after the rTM treatment, without statistical difference. However, CRP, platelet count, PT-INR and DIC scores were significantly improved after the rTM treatment(p<0.05). CONCLUSIONS: rTM may be useful in the treatment of DIC for surgical OE patients.

[A Rapid Clinical Course of Pulmonary Embolism Associated with Gallbladder Mucinous Carcinoma].

A 51-year-old woman with edema of the lower extremities and exertional dyspnea was admitted to our hospital. Enhanced CT revealed thrombi of the pulmonary artery and a gallbladder tumor. After anticoagulation therapy was started on her, anemia and jaundice progressed; thus, endoscopic retrograde cholangiopancreatography(ERCP)was performed on suspicion of bleeding from a gallbladder tumor. We performed cholecystectomy in emergency to control the anemia due to hemorrhage. Oxygenation suddenly worsened intraoperatively, maintaining her blood pressure became difficult, and the patient decompensated. The histopathological diagnosis was gallbladder mucinous carcinoma with severe lymphatic invasion. Although an autopsy was not performed, pulmonary artery embolism derived from a tumor embolus was the suspected cause of the sudden change of the clinical course.

[Hepatectomy for Intrahepatic Combined Hepatocellular Carcinoma Recurrence in a Hemophilia a Patient with Human Immunodeficiency Virus and Hepatitis C Virus-A Case Report].

A 40's Japanese man had a history of blood transfusion and administration of treatment coagulation factors for hemophilia A since he was 6 years old. He has been on IFN treatment for hepatitis C since he was 14 years old. Lastly, he has been undergoing HAART therapy for human immunodeficiency virus infection since he was 18 years old. Three years ago, he underwent partial hepatectomy for a tumor located in segment 8 of his liver and was diagnosed with combined hepatocellular carcinoma(CHC). Two years and 7 months after the operation, 2 intrahepatic recurrences were detected in the left lobe. He was referred to our hospital to undergo curative resection, and we performed a left lobectomy of the liver for the CHC recurrences. Perioperatively, supplemental factor Ⅷ was administered via APTT. Its activity was used as an index. Postoperatively, the patient was well, was discharged 13 days after surgery, and remained recurrence-free for 4 months.

[A Resected Case of Metachronous Solitary Metastasis of Jejunum after Surgery of Triple Colon Cancers].

A 68-year-old man underwent partial colectomy and double-barrel colostomy for an obstructive colon cancer of the splenic flexure at another hospital 10 years before. He was referred to us with an examination of anemia pointed out in human dock. Lower gastrointestinal endoscopy revealed the tumor occupied the remnant descending colon. We performed remnant left hemicolectomy and diagnosed as triple colon cancers. Six months after the initial operation, he was admitted to us with the chief complaints of abdominal fulness and vomit. Abdominal CT and radiologic enteroclysis after decompression used the ileus tube revealed complete stenosis at the small intestine. We performed surgery with a suspicion of obstruction of the small intestine. The tumor, 5 cm in diameter, occupied the jejunum was detected, and partial resection of the jejunum was performed. Histologically, the tumor was diagnosed as solitary metastasis of jejunum.

[Radiofrequency Ablation for Colorectal Liver Metastases].

AIM: The significance of radiofrequency ablation(RFA)for colorectal liver metastases(CRLM)remains to be elucidated. Therefore, this retrospective study aimed to evaluate the therapeutic efficacy of RFA for local recurrence of CRLM. SUBJECTS: Between June 2005 and June 2017, we retrospectively examined 63 patients(137 nodules)with CRLM who underwent RFA. RESULTS: The local recurrence rate was 36.5%, and the median local recurrence free survival(LRFS)was 26.3 months. We compared treatment background between the 2 groups with(50 nodules)and without(87 nodules)local recurrence. In the multivariate analysis, tumor size of the ablated lesion and method for ablation(direct tumor puncture)were independent risk factors for local recurrence. Receiver operating characteristic curve for tumor size of the ablated lesion showed an optimal cutoff value for tumor size of 1.8 cm(AUC=0.734, 95%CI: 0.612-0.855, p<0.0001). CONCLUSIONS: RFA for effective control of local recurrence of CRLM might be suitable for selected patients with tumor size of ablated lesion ofC1.8 cm and no touch ablation method.

[A Resected Case of Hilar Cholangiocarcinoma Confirmed as Pathological Complete Response Following Neoadjuvant S-1 Monotherapy].

A 74-year-old man was admitted to a local hospital with liver dysfunction. Imaging modalities revealed bile duct stenosis at the bifurcation of the anterior and posterior trunk. Exfoliative cytology of the bile and brushing cytology of the bile duct both revealed Class Ⅴ, and biopsy from the stenotic bile duct showed well differentiated adenocarcinoma. We diagnosed the patient with hilar cholangiocarcinoma and performed extended right bisectionectomy and biliary reconstruction after percuta- neous transhepatic right portal vein embolization(PTPE). Preoperatively, he was administered S-1(80mg/body weight/day) orally for 19 days. Histopathological assessment of the resected specimen revealed hemosiderin-laden macrophages without viable cancer cells, confirmingpatholog ical complete response(pCR).

Efficacy of sequential sorafenib plus hepatic arterial infusion chemotherapy in patients with Barcelona Clinic Liver Cancer stage B and C hepatocellular carcinoma: a retrospective single-institution study.

AIM OF THE STUDY: To evaluate the efficacy of sequential combination therapy using sorafenib and hepatic arterial infusion chemotherapy (HAIC) in patients with Barcelona Clinic Liver Cancer stage B/C hepatocellular carcinoma (HCC). MATERIAL AND METHODS: We recruited 98 BCLC stage B/C HCC patients at our institute, who received either sorafenib monotherapy or planned sequential sorafenib-HAIC combination therapy. A total of 26 patients (combination group) received sorafenib for one or two months, followed by HAIC with a single dose of cisplatin-lipiodol suspension and a continuous infusion of 5-fluorouracil. Sorafenib-HAIC cycles were repeated every 2-3 months. The remaining 72 patients (control group) were treated with sorafenib alone. Clinical characteristics and treatment outcomes were compared between the groups. Inverse probability weighting (IPW) using propensity scores was applied to adjust for the between-group differences in baseline characteristics. RESULTS: The combination group had a significantly lower frequency of extrahepatic metastasis and BCLC stage C disease compared with the control group but had more intrahepatic lesions. The crude median overall survival (OS) was 17.1 months in the combination group compared with 9.7 months in the control group (p = 0.01). The objective response rate was 23.1% in the combination group vs. 6.9% in the control group (p = 0.06). Multivariate analysis identified receipt of sorafenib-HAIC combination (HR: 0.521, 95% CI: 0.297-0.915, p = 0.02) and α-fetoprotein (≥ 400 ng/ml) at baseline as independent factors associated with OS. After adjustment with IPW the combination group still had significantly better OS than the control group (p = 0.04). CONCLUSIONS: The sequential sorafenib-HAIC combination can be an effective and promising treatment option for selected patients with BCLC stage B/C HCC.

The preoperative modified Glasgow prognostic score for the prediction of survival after pancreatic cancer resection following non-surgical treatment of an initially unresectable disease.

AIM OF THE STUDY: Recent advances in chemotherapy have increasingly enabled conversion surgery (CS) in patients with initially unresectable pancreatic cancer (PC), but patient selection remains controversial. We examined the characteristics of patients who would benefit from this procedure. MATERIAL AND METHODS: The clinical and pathological data of 38 patients with unresectable PC, who underwent CS after a favourable response to chemo(radio)therapy at our institute, were investigated. Univariate and multivariate analyses were performed to identify predictors for overall survival (OS). Several inflammation-based scores, such as the modified Glasgow prognostic score (mGPS), were also evaluated. RESULTS: The patients included 13 with locally advanced disease and 25 with metastatic disease. After non-surgical treatment with a median duration of six months, 27 patients (71%) underwent R0/1 resection, and the remainder underwent R2 resection. The two-year and five-year OS from the initial treatment for all patients were 64% and 29%, respectively, and the median survival was 29.1 months. Univariate analysis showed that age < 62 years, preoperative CA19-9 decrease rate ≥ 89%, preoperative mGPS-0, and R0/1 resection were related to a favourable OS. R0/1 resection and mGPS-0 were independent prognostic factors according to multivariate analysis. CONCLUSIONS: Preoperative mGPS is a potential predictor of survival and can aid selection of patients for whom CS could yield promising prognosis for initially unresectable PC.

Patterns of Local Recurrence and Oncologic Outcomes in T3 Low Rectal Cancer (≤5 cm from the Anal Verge) Treated With Short-Course Radiotherapy With Delayed Surgery : Outcomes in T3 Low Rectal Cancer Treated With Short-Course Radiotherapy With Delayed Surgery.

BACKGROUND: Short-course radiotherapy with delayed surgery (SRT-delay) is still under clinical investigation for its efficacy in treating low rectal cancer (≤5 cm from the anal verge). This study was designed to assess the pattern of local recurrence and oncologic outcomes in T3 low rectal cancer treated with SRT-delay. METHODS: This study enrolled T3 low rectal cancer patients without distant metastasis between 2003 and 2015. All patients received total mesorectal excision following SRT-delay (25 Gy/10 fractions/5 days + S-1 radiosensitizer with a 4-week delay of surgery). The median follow-up period was 69 (range 1-149) months. RESULTS: A total 119 consecutive patients had low rectal cancer; 104 (87.4 %) underwent intersphincteric resection (ISR), and 15 (12.6 %) underwent abdominoperineal resection (APR). Fifty-six patients (47.1 %) were ypT-downstaged, 86 (72.2 %) were ypN0, and 10 (8.4 %) had circumferential resection margin involvement. The 5-year local recurrence-free survival, recurrence-free survival, and overall survival were 93.0, 76.2, and 80.5 %, respectively. Nine patients experienced local recurrence: lateral pelvic recurrence in six patients (5.0 %) and central pelvic recurrence in three (2.5 %). CONCLUSIONS: A total of 87.4 % of sphincter-preserving surgeries were performed for T3 low rectal cancer following SRT-delay. Pathological tumor downstaging, circumferential resection margin involvement, local recurrence, and oncologic outcomes were acceptable; therefore, the SRT-delay regimen may be an option for treating T3 low rectal cancer.

Clinicopathological outcomes of preoperative chemoradiotherapy using S-1 plus Irinotecan for T4 lower rectal cancer.

PURPOSE: To investigate the clinicopathological outcomes of patients with T4 lower rectal cancer treated using preoperative chemoradiotherapy with S-1 plus Irinotecan. METHODS: Between 2005 and 2011, 35 patients with T4M0 lower rectal cancer, diagnosed initially as T4a in 12 and as T4b in 23, were treated with 45 Gy of radiotherapy concomitantly with S-1 plus Irinotecan. The median follow-up period was 50.6 months (range 2-123 months). RESULTS: A total of 32 patients (91.4 %) completed the radiotherapy and 26 (74.3 %) completed the full chemotherapy regimen. Radical surgery was then performed in 33 (94.3 %) of the 35 patients after the exclusion of two patients, who had macroscopic residual disease. The pathological diagnosis was downstaged from T4a to ypT0-3 in all 12 of those patients (100 %) and from T4b to ypT0-4a in 20 of those 23 patients (87.0 %). The tumor regression grade of 1a/1b/2/3 (complete response) was 10/8/15/2, respectively. In terms of long-term survival, the 5-year local relapse-free survival rate was 74.8 % and the recurrence-free survival rate was 52.0 %. CONCLUSIONS: This regimen may result in favorable downstaging. Moreover, in this series, pathological evidence of involvement of adjacent organs was rare following preoperative chemoradiotherapy, in the patients with disease diagnosed as T4b at the initial staging.

The short-term outcomes of induction SOX (S-1 + oxaliplatin) ± cetuximab chemotherapy followed by short-course chemoradiotherapy in patients with poor-risk locally advanced rectal cancer.

PURPOSE: To evaluate the safety and efficacy of induction SOX (S-1 + oxaliplatin) ± cetuximab chemotherapy followed by short-course chemoradiotherapy and surgery in patients with poor-risk locally advanced rectal cancer. METHODS: We enrolled eligible patients with poor-risk rectal cancer defined as T3 lower rectal cancer with mesorectal fascia involvement, T4a or T4b tumors or cases with lateral lymph node swelling. The primary endpoint was a pathological complete response (pCR), and the secondary endpoints were the objective response rate (ORR) and the pathological high response rate (Grade 2 plus 3). RESULTS: Twenty eligible patients were enrolled. The majority (75.0 %, 15/20) of the patients completed four cycles of induction chemotherapy, and all patients completed the radiotherapy (25 Gy/10 fractions/5 days). The global rate of Grade 3-4 toxicities was 30.0 % (6/20 patients). The ORRs were 85.0 % (17/20) and 95.0 % (19/20) in the patients who underwent R0 and R1 resection, respectively. The pathological high response rate was 70.0 % (14/20) and the pCR was 10.0 % (2/20). CONCLUSION: The regimen of induction SOX (S-1 + oxaliplatin) ± cetuximab chemotherapy followed by short-course chemoradiotherapy is safe and is associated with good tumor regression in patients with poor-risk locally advanced rectal cancer.

Comparative study of percutaneous radiofrequency ablation and hepatic resection for small, poorly differentiated hepatocellular carcinomas.

AIM: Histologically, poorly differentiated hepatocellular carcinomas (HCC) are considered highly malignant. Here, we aimed to evaluate the relative efficacy and safety of hepatic resection or radiofrequency ablation (RFA) for treating this malignancy. METHODS: Between April 2004 and May 2011, we enrolled 48 patients who had poorly differentiated HCC that had been diagnosed postoperatively by pathological assessment. All the tumors had a maximum diameter of 3 cm and all patients had three or less tumors. Fifteen of these patients underwent hepatic resection (HR group) and 33 patients underwent RFA (RF group). The patient background, tumor characteristics, overall survival rate and recurrence-free survival rate were assessed in both groups. RESULTS: The mean maximum tumor diameter was 2.5 and 2.0 cm in the HR and RF groups, respectively. The prothrombin activity level was 94% and 86% in the HR and RF groups, respectively. The 1-, 3- and 5-year cumulative survival rates were 89.1%, 68.7% and 68.7%, respectively, in the HR group, and 59.2%, 40.9% and 32.7%, respectively, in the RF group. The 1-, 3- and 5-year recurrence-free survival rates were 85.1%, 64.8% and 48.6%, respectively, in the HR group, and 29.0%, 7.2% and 7.2%, respectively, in the RF group. There was a significant difference between these groups (P < 0.05). CONCLUSION: As hepatic resection has greater efficacy than RFA in the treatment of poorly differentiated HCC, even in cases with a small tumor size, we recommend its use for this malignancy.

Predictive factors of portal vein thrombus following splenectomy in patients with severe cirrhosis.

BACKGROUND/AIMS: Splenectomy is performed in patients with severe cirrhosis who have a low platelet count. A portal vein thrombus (PVT) is one of the complications associated with splenectomy. This study aimed to identify predictive factors of postoperative PVT following splenectomy. METHODOLOGY: Twentyeight patients who underwent splenectomy between April 2003 and March 2013 were retrospectively analyzed. Patients were divided into two groups: the PVT(+) group comprising 11 patients who developed postoperative PVT, and the PVT(-) group comprising 17 patients who did not develop postoperative PVT. The patient characteristics of the 2 groups were analyzed. Results: In univariate analysis, the platelet count, rate of simultaneous treatment of hepatocellular carcinoma, and preoperative spleen volume were significantly different between the groups (p < 0.05). In multivariate analysis, preoperative spleen volume alone was an independent factor associated with the development of PVT (p = 0.007). At a preoperative spleen volume cutoff of 450 mL, the sensitivity and specificity were 90% and 73%, respectively. CONCLUSIONS: In patients with severe cirrhosis scheduled to undergo splenectomy, if the preoperative spleen volume is >450 mL, as measured by enhanced computed tomography, preventive administration of anticoagulant therapy is recommended to reduce the risk of PVT development.

Risk of abscess formation after liver tumor radiofrequency ablation: a review of 8 cases wtih a history of enterobiliary anastomosis.

BACKGROUND/AIMS: Rates of postoperative complications after radiofrequency ablation (RFA) remain high for patients who have previously undergone surgery associated with the bile duct. Our purpose is to clarify the rate of postoperative complication and identify preoperative risk factors. METHODOLOGY: This retrospective study reviewed patient backgrounds, ablation areas, and preoperative laboratory data in 8 patients (9 tumors) who underwent RFA after enterobiliary anastomosis. RESULTS: Postoperative complications occurred in 6 of the 8 cases (75%). Postoperative liver abscesses occurred in both the cases of tumor located in the hepatic hilum, i.e., tumor located 5­30 mm from the site of enterobiliary anastomosis. Of the 6 patients with peripherally located tumors, postoperative liver abscesses occurred in 4 patients with elevated preoperative levels of alkaline phosphate (ALP), 3 of whom required abscess drainage. No postoperative complications occurred in the 2 patients with tumors located in the periphery of the liver and with normal preoperative ALP levels. CONCLUSIONS: Postoperative complications are frequent when RFA is performed in patients who have previously undergone enterobiliary anastomosis. These results suggest that RFA after enterobiliary anastomosis should not be recommended. However, the risk may be lower in cases where the nodules are located in the liver periphery and the preoperative ALP level is low.