Survival outcome of surgical resection compared to non-resection for Bismuth type IV perihilar cholangiocarcinoma

BACKGROUND/OBJECTIVES

Bismuth type IV perihilar cholangiocarcinoma has been considered an unresectable disease. The aim of the study was to assess whether the surgical resection of type IV perihilar cholangiocarcinoma was associated with better survival rates.

METHODS

The data of 117 patients diagnosed with type IV perihilar cholangiocarcinoma at Keimyung University Dongsan Hospital from 2005 to 2020 were retrospectively reviewed. The Bismuth type was assigned based on the patient's radiological imaging findings. The primary outcomes were the surgical results and median overall survival.

RESULTS

The demographic characteristics of the 117 patients with type IV perihilar cholangiocarcinoma were comparable between the surgical resection and non-resection groups. Thirty-two (27.4%) patients underwent surgical resections. A left hepatectomy was performed in 16 patients, right hepatectomy in 13 patients, and a central bi-sectionectomy in three patients. The remaining 85 patients received non-surgical treatments. Thirteen (10.9%) received palliative chemotherapy, and 72 (60.5%) patients received conservative treatment including biliary drainage. The patients in the resection group showed significantly longer median overall survival than the patients in the non-resection group (32.4 vs 16.0 months; P = 0.002), even though the positive resection margin rate was high (62.5%). Surgical complications occurred in 15 (46.9%) patients. Complications of Clavien-Dindo classification grade III or higher occurred in 13 (40.6%) patients and grade V in two patients (6.3%).

CONCLUSION

Surgical resection for Bismuth type IV perihilar cholangiocarcinoma is technically demanding. The survival of the resection group was significantly better than that of the non-resection group. The resection of selected patients achieved a curative goal with acceptable postoperative morbidity, although the microscopically positive resection margin rate was high.

Associations of Serum Tumor Biomarkers with Integrated Genomic and Clinical Characteristics of Hepatocellular Carcinoma

INTRODUCTION

Serum α-fetoprotein (AFP), Lens culinaris agglutinin-reactive AFP (AFP-L3), and des-γ-carboxy-pro-thrombin (DCP) are useful biomarkers of hepatocellular carcinoma (HCC). However, associations among molecular characteristics and serum biomarkers are unclear. We analyzed RNA expression and DNA variant data from The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC) to examine their associations with serum biomarker levels and clinical data.

METHODS

From 371 TCGA-LIHC patients, we selected 91 seen at 3 institutions in Korea and the USA and measured AFP, AFP-L3, and DCP from preoperatively obtained serum. We conducted an integrative clinical and molecular analysis, focusing on biomarkers, and validated the findings with the remaining 280 patients in the TCGA-LIHC cohort.

RESULTS

Patients were categorized into 4 subgroups: elevated AFP or AFP-L3 alone (↑AFP&L3), elevated DCP alone (↑DCP), elevation of all 3 biomarkers (elevated levels of all 3 biomarkers [↑All]), and reference range values for all biomarkers (RR). CTNNB1 variants were frequently observed in ↑DCP patients (53.8%) and RR patients (38.5%), but ↑DCP patients with a CTNNB1 variant had worse survival than RR patients. TP53 sequence variants were associated with ↑AFP (30.8%) and ↑DCP (30.8%). The Wnt-β-catenin signaling pathway was activated in the ↑AFP&L3, whereas liver-related Wnt signaling was activated in the RR. TGF-β and VEGF signaling were activated in ↑AFP&L3, whereas dysregulated bile acid and fatty acid metabolism were dominant in ↑DCP. We validated these findings by showing similar results between the test cohort and the remainder of the TCGA-LIHC cohort.

CONCLUSIONS

Serum AFP, AFP-L3, and DCP levels can help predict variants in the genetic profile of HCC, especially for TP53 and CTNNB1. These findings may facilitate development of an evidence-based approach to treatment.

Liquid Biopsy from Bile-Circulating Tumor DNA in Patients with Biliary Tract Cancer

Simple Summary

Utilization of cell free DNA for diagnosing and monitoring patients with biliary tract cancers is emerging and promising. The strength of the present study is in its description of a novel approach using bile rather than blood or tissue samples, which is particularly relevant in biliary tract cancers. This paper largely serves as a proof of concept that ctDNA from bile is potentially feasible.

Abstract

Although liquid biopsy of blood is useful for cancer diagnosis and prediction of prognosis, diagnostic and prognostic value of ctDNA in bile fluid for BTCs are not clear yet. To determine whether liquid biopsy for circulating tumor DNA (ctDNA) can replace tissue biopsy when assessing somatic mutations in biliary tract cancers (BTCs). Bile samples were obtained from 42 patients with BTC. Matched formalin-fixed paraffin-embedded (FFPE) samples were obtained from 20 of these patients and matched plasma samples from 16 of them. Droplet digital PCR (ddPCR) was used for detection KRAS somatic mutation. KRAS mutations were identified in the bile ctDNA of 20 of 42 (48%) patients. Patients with mutant KRAS showed significantly worse survival than those with wild-type KRAS (2-year survival rates: 0% vs. 55.5%, respectively; p = 0.018). There was 80.0% mutational concordance between the paired bile ctDNA and FFPE samples, and 42.9% between the plasma and FFPE samples. On transcriptomic sequencing of one set of paired bile and FFPE samples, expression level of KRAS-associated signaling oncogenes in the bile and tissue samples showed a strong positive correlation (r = 0.991, p < 0.001). Liquid biopsy of bile reliably detect mutational variants within the bile ctDNA of BTC patients. These results suggest that bile is an effective biopsy fluid for ctDNA analysis.

Molecular heterogeneity in intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) is a heterogeneous primary liver cancer, and currently there exist only a few options of targeted therapy. Histopathologically, iCCA is sub-classified according to morphology (mass forming type, periductal infiltrating type, and intraductal growing type) and histology (small duct type and large duct type). According to different histopathological types, clinical features such as risk factors and prognosis vary. Recent developments in genomic profiling have revealed several molecular markers for poor prognosis and activation of oncogenic pathways. Exploration of molecular characteristics of iCCA in each patient is a major challenge in a clinical setting, and there is no effective molecular-based targeted therapy. However, several recent studies suggested molecular-based subtypes with corresponding clinical and pathological features. Even though the subtypes have not yet been validated, it is possible that molecular features can be predicted based on clinicopathological characteristics and that this could be used for a more rational approach to integrative clinical and molecular subclassification and targeted therapy. In this review, we explored the genomic landscape of iCCA and attempted to find relevance between clinicopathologic and molecular features in molecular subtypes in several published studies. The results reveal future directions that may lead to a rational approach to the targeted therapy.

Outcomes of Pediatric Liver Transplantation in Korea Using Two National Registries

Background: This retrospective study aimed to evaluate overall survival and the risk factors for mortality among Korean pediatric liver transplantation (LT) patients using data from two national registries: the Korean Network Organ Sharing (KONOS) of the Korea Centers for Disease Control and Prevention and the Korean Organ Transplantation Registry (KOTRY). Methods: Prospectively collected data of 755 pediatric patients who underwent primary LT (KONOS, February 2000 to December 2015; KOTRY, May 2014 to December 2017) were retrospectively reviewed. Results: The 1-, 5-, 10-, and 15-year survival rates were 90.6%, 86.7%, 85.8%, and 85.5%, respectively, in KONOS, and the 1-month, 3-month, 1-year, and 2-year survival rates were 92.1%, 89.4%, 89.4%, and 87.2%, respectively, in KOTRY. There was no significant difference in survival between the two registries. Multivariate analysis identified that body weight ≥6 kg (p <0.001), biliary atresia as underlying liver disease (p = 0.001), and high-volume center (p < 0.001) were associated with better survival according to the KONOS database, while hepatic artery complication (p < 0.001) was associated with poorer overall survival rates according to the KOTRY database. Conclusion: Long-term pediatric patient survival after LT was satisfactory in this Korean national registry analysis. However, children with risk factors for poor outcomes should be carefully managed after LT.

Prognostic subclass of intrahepatic cholangiocarcinoma by integrative molecular-clinical analysis and potential targeted approach

BACKGROUND

Although molecular characterization of iCCA has been studied recently, integrative analysis of molecular and clinical characterization has not been fully established. If molecular features of iCCA can be predicted based on clinical findings, we can approach to distinguish targeted treatment. We analyzed RNA sequencing data annotated with clinicopathologic data to clarify molecular-specific clinical features and to evaluate potential therapies for molecular subtypes.

METHODS

We performed next-generation RNA sequencing of 30 surgically resected iCCA from Korean patients and the clinicopathologic features were analyzed. The RNA sequences from 32 iCCA resected from US patients were used for validation.

RESULTS

Patients were grouped into two subclasses on the basis of unsupervised clustering, which showed a difference in 5-year survival rates (48.5% vs 14.2%, p = 0.007) and similar survival outcome in the US samples. In subclass B (poor prognosis), both data sets were similar in higher carcinoembryonic antigen and cancer antigen 19-9 levels, underlying cholangitis, and bile duct-type pathology; in subclass A (better prognosis), there was more frequent viral hepatitis and cholangiolar-type pathology. On pathway analysis, subclass A had enriched liver-related signatures. Subclass B had enriched inflammation-related and TP53 pathways, with more frequent KRAS mutations. CCA cell lines with similar gene expression patterns of subclass A were sensitive to gemcitabine.

CONCLUSIONS

Two molecular subtypes of iCCA with distinct clinicopathological differences were identified. Knowledge of clinical and pathologic characteristics can predict molecular subtypes, and knowledge of different subtype signaling pathways may lead to more rational, targeted approaches to treatment.

Appropriate treatment modality for solitary small hepatocellular carcinoma: Radiofrequency ablation vs. resection vs. transplantation?

There has been controversy regarding the first-line treatment modality for the patients who have small solitary hepatocellular carcinoma (HCC); radiofrequency ablation (RFA) or percutaneous ethanol injection (PEI), surgical hepatic resection (HR) and liver transplantation (LT). For selection of treatment modality of HCC, it should be considered of hepatic reservoir function as well as the tumor stage. If the liver function is good enough, HR may be the first choice regardless of the tumor size. However, recent studies comparing RFA with resection showed comparable outcome and similar survival rates. RFA, HR and LT provide good outcome for patients who have small HCCs. RFA would be desired in patients who have below 3.0 cm in size and low alpha-fetoprotein (<200 ng/mL). However, in small HCC with high tumor marker, HR should be considered. Better patient selection for the ‘resection first’ approach and early detection of recurrence can achieve better outcomes of the salvage LT strategy. Another benefit of resection first strategy is that it make possible to do enlist of LT for patients before recurrence at high risk of HCC recurrence after resection on the basis of pathologic aggressiveness, microvascular invasion and/or satellites nodule. They should be applied appropriately according to the tumor size, location, tumor markers and underlying liver parenchymal disease.

The optimal surgical resection approach for T2 gallbladder carcinoma: evaluating the role of surgical extent according to the tumor location

Purpose

The clinical behavior of T2 gallbladder cancer varies among patients. The aims of this study were to identify prognostic factors for survival and recurrence, and to determine the optimal surgical strategy for T2 gallbladder cancer.

Methods

We conducted a retrospective analysis of 78 patients with T2 gallbladder cancer who underwent surgical resection for gallbladder cancer.

Results

Twenty-eight patients (35.9%) underwent simple cholecystectomy and 50 (64.1%) underwent extended cholecystectomy. Among 56 patients without LN metastasis (n = 20) or unknown LN status (no LN dissection, n = 36), the 5-year disease-free survival rates were 81.6%, and 69.8% (P = 0.080). In an analysis according to tumor location, patients with tumors located on the hepatic side (n = 36) had a higher recurrence rate than patients with tumors located on the peritoneal side only (n = 35) (P = 0.043). On multivariate analysis, R1 resection and lymph node metastasis were significant, independent prognostic factors for poor disease-free and overall survival.

Conclusion

R0 resection and LN dissection are an appropriate curative surgical strategy in patients with T2 gallbladder cancer. Tumors located on the hepatic side show worse prognosis than tumors located on the peritoneal side only, hepatic resection should be considered.

Impact of preoperative endoscopic cholangiography and biliary drainage in Ampulla of Vater cancer

BACKGROUND

Ampulla of Vater (AOV) carcinoma is a rare malignancy but has a relatively good prognosis. The aims of this study were to determine the clinicopathologic factors associated with survival and disease recurrence in patients with AOV cancer, focusing on the impact of preoperative endoscopic retrograde cholangiopancreatography (ERCP) and type of biliary drainage (endoscopic retrograde biliary drainage [ERBD] or percutaneous transhepatic biliary drainage [PTBD]).

METHODS

We retrospectively reviewed the medical records of 80 patients who underwent curative resection for AOV cancer at a single institution between 1995 and 2015. The clinicopathologic factors associated with survival and disease recurrence were analyzed using univariate and multivariable tests.

RESULTS

The 5-year disease-free and overall actuarial survival rates were 39.3% and 51.3%, respectively. Moderate or poor differentiation, preoperative ERCP, advanced T stage, lymph node metastases, advanced stage and lymphovascular invasion were associated with disease-free survival in univariate analyses. The prognosis was worse in patients who underwent ERBD than in patients who underwent PTBD or no biliary drainage. Multivariable analysis showed that advanced AJCC stage and preoperative ERCP were independent risk factors for recurrence. Patient who underwent preoperative ERCP had a significantly higher rate of early distant metastasis within 1 year, especially in patients with early stage AOV cancer.

CONCLUSIONS

Preoperative ERCP was an independent risk factor for postoperative recurrence in patients with AOV cancer, and is characterized by early distant metastasis in early stage cancer. Therefore, unnecessary ERCP should be avoided in patients with AOV cancer. If biliary drainage is necessary, PTBD may be preferred to ERBD in AOV cancer.

Anatomical resection of hepatocellular carcinoma: A critical review of the procedure and its benefits on survival

Hepatocellular carcinoma (HCC) is the sixth most common type of cancer and the third most frequent cause of cancer-related death. Advances in preoperative assessment of HCC (e.g., imaging studies and liver function tests), surgical techniques, and postoperative care have improved the surgical outcomes and survival of patients who undergo hepatic resection for HCC. However, in the last 20 years, the long-term survival after hepatectomy has remained unsatisfactory owing to the high rates of local recurrence and multicentric occurrence. Anatomical liver resection (AR) was introduced in the 1980s. Although several studies have revealed tangible benefits of AR for HCC, these benefits are still debated. Because most HCCs occur in patients with liver cirrhosis and poor hepatic function, there are many factors that affect survival, including the surgical method. Nevertheless, many studies have documented the perioperative and long-term benefits of AR in various conditions. In this article, we review the results of several recently published, well-designed comparative studies of AR, to investigate whether AR provides real benefits on survival outcomes. We also discuss the potential pitfalls associated with this approach.

Prognostic factors after hepatic resection for the single hepatocellular carcinoma larger than 5 cm

Purpose

This study aimed to determine which factors affect the prognosis of hepatectomy for hepatocellular carcinoma (HCC) larger than 5 cm, including the prognostic difference between tumor sizes from 5–10 cm and larger than 10 cm.

Methods

The medical records of 114 patients who underwent hepatectomy for single HCC larger than 5 cm were reviewed and analyzed retrospectively.

Results

In the analysis of the entire cohort of 114 patients, the 5-year overall and diseases-free survival rates were 50% and 29%, respectively. In a comparison of survival rates between groups, tumor sizes of 5 to 10 cm and larger than 10 cm, the overall and disease-free survival rates were not significantly different, respectively (54% vs. 41%, P = 0.433 and 33% vs. 23%, P = 0.083). On multivariate analysis, positive hepatitis B, high prothrombin induced by vitamin K absence or antagonist-II levels over 200 mIU/mL, and vascular invasion (micro- and macrovascular invasion) were independent prognostic factors for recurrence after hepatic resection. However, tumor size larger than 10 cm was not significant for recurrence after resection.

Conclusion

This study shows that surgical resection of solitary HCC larger than 5 cm showed favorable overall survival. And there is no survival difference with tumors between 5–10 cm and larger than 10 cm.

Confinement to the intrapancreatic bile duct is independently associated with a better prognosis in extrahepatic cholangiocarcinoma

BACKGROUND

Actual differences of long term outcome of extrahepatic cholangiocarcinoma according to the location of the tumor have not yet been studied. The aim of this study was to evaluate the prognosis and optimal surgical procedure for middle (BD) cancer.

METHODS

Among 109 patients with carcinoma of the extrahepatic BD underwent surgical resection, curative resection of extrahepatic BD cancer was performed in 90 patients. They were classified into three groups according to the location of tumors: DISTAL (n = 32), tumor was confined to the intrapancreatic bile duct; MID (n = 20), tumor was located between below the confluence of the hepatic duct bifurcation and suprapancreatic portion of the BD; and DIFFUSE (n = 38), tumor was located diffusely.

RESULTS

Tumor involving the middle BD (MID or DIFFUSE) had a higher rate of perineural invasion as compared to the DISTAL group. The overall and disease-free survival rate for the MID or DIFFUSE group was significantly worse than that of DISTAL. In the MID/DIFFUSE group, there was no significant difference of survival according to the type of the operation (pancreaticoduodenectomy or segmental BD resection). The multivariate analysis showed that tumor involving middle BD (MID or DIFFUSE group) and node metastasis were independently poor prognostic factors for the disease free and overall survival.

CONCLUSION

Extrahepatic cholangiocarcinoma involving the extrapancreatic BD has a worse prognosis than those confined to the intrapancreatic BD. In patients with tumors confined to the middle BD, BD resection can be considered as an alternative surgical procedure to pancreaticoduodenectomy, if an R0 resection can be accomplished.

Successful Treatment of Combined Aspergillus and Cytomegalovirus Abscess in Brain and Lung After Liver Transplant for Toxic Fulminant Hepatitis

Invasive aspergillosis is one of the most important and fatal complications after liver transplant, especially in patients with involvement of the central nervous system. We present a case of a patient who developed cerebral and pulmonary aspergillosis, coinfected with cytomegalovirus, after liver transplant for toxic fulminant hepatitis. The patient was treated successfully with neurosurgical intervention and voriconazole. Voriconazole is considered more effective in cerebral aspergillosis than other anti-fungal agents due to the greater penetration into central nervous system and higher cerebrospinal fluid and brain tissue levels.

AROS Is a Significant Biomarker for Tumor Aggressiveness in Non-cirrhotic Hepatocellular Carcinoma

Despite a low risk of liver failure and preserved liver function, non-cirrhotic hepatocellular carcinoma (HCC) has a poor prognosis. In the current study, we evaluated an active regulator of SIRT1 (AROS) as a prognostic biomarker in non-cirrhotic HCC. mRNA levels of AROS were measured in tumor and non-tumor tissues obtained from 283 non-cirrhotic HCC patients. AROS expression was exclusively up-regulated in recurrent tissues from the non-cirrhotic HCC patients (P = 0.015) and also in tumor tissues irrespective of tumor stage (P < 0.001) or BCLC stage (P < 0.001). High mRNA levels of AROS were statistically significantly associated with tumor stage (P < 0.001), BCLC stage (P = 0.007), alpha fetoprotein (AFP) level (P = 0.013), microvascular invasion (P = 0.001), tumor size (P = 0.036), and portal vein invasion (P = 0.005). Kaplan-Meir curve analysis demonstrated that HCC patients with higher AROS levels had shorter disease-free survival (DFS) in both the short-term (P < 0.001) and long-term (P = 0.005) compared to those with low AROS. Cox regression analysis demonstrated that AROS is a significant predictor for DFS along with large tumor size, tumor multiplicity, vascular invasion, and poor tumor differentiation, which are the known prognostic factors. In conclusion, AROS is a significant biomarker for tumor aggressiveness in non-cirrhotic hepatocellular carcinoma.

Improved severe hepatopulmonary syndrome after liver transplantation in an adolescent with end-stage liver disease secondary to biliary atresia

Hepatopulmonary syndrome (HPS) is a serious complication of end-stage liver disease, which is characterized by hypoxia, intrapulmonary vascular dilatation, and liver cirrhosis. Liver transplantation (LT) is the only curative treatment modality for patients with HPS. However, morbidity and mortality after LT, especially in cases of severe HPS, remain high. This case report describes a patient with typical findings of an extracardiac pulmonary arteriovenous shunt on contrast-enhanced transesophageal echocardiography (TEE), and clubbing fingers, who had complete correction of HPS by deceased donor LT. The patient was a 16-year-old female who was born with biliary atresia and underwent porto-enterostomy on the 55th day after birth. She had been suffered from progressive liver failure with dyspnea, clubbing fingers, and cyanosis. Preoperative arterial blood gas analysis revealed severe hypoxia (arterial O2 tension of 54.5 mmHg and O2 saturation of 84.2%). Contrast-enhanced TEE revealed an extracardiac right-to-left shunt, which suggested an intrapulmonary arteriovenous shunt. The patient recovered successfully after LT, not only with respect to physical parameters but also for pychosocial activity, including school performance, during the 30-month follow-up period.

Inflammatory pseudotumors mimicking intrahepatic cholangiocarcinoma of the liver; IgG4-positivity and its clinical significance

BACKGROUND

Inflammatory pseudotumor (IPT) of the liver is a benign condition with a good prognosis. However, it is difficult to distinguish clinical and radiological findings of IPT from those of malignancies. The aims of this study are to determine the clinical, radiological, and pathological characteristics, particularly relating to the role of the autoimmune mechanism in the development of inflammatory pseudotumours (IPTs) of the liver, and to suggest appropriate diagnostic and therapeutic strategy.

STUDY DESIGN

The clinical, diagnostic, and pathological characteristics including IgG4 immunohistochemical stain and follow-up data of 22 IPT patients were retrospectively analyzed.

RESULTS

The patients were 16 men and 6 women with a mean age of 59 years. Fifteen patients (68.2%) had associated biliary diseases. Of the 16 patients treated conservatively, the masses completely resolved in 10 patients, and reduced in size in 5 patients within the first 6 months. The remaining 6 patients were treated by surgical resection. IgG4 staining of 17 tissue samples from 22 patients were negative, most of the infiltrate being of fibrohistiocytic type, whereas 4 of 5 lymphoplasmacytic cells of dominant tumors show positive staining of IgG4. Although IgG4-related sclerosing cholangitis was mostly of lymphoplasmacytic type, other histological and clinical characteristics were similar in both types of IPTs.

CONCLUSIONS

IPTs of the liver can be diagnosed based on radiological and pathological findings by needle biopsy. Although the lymphoplasmacytic type of IPTs seems to correspond to IgG4-related disease, as assessed by IgG4 immunohistochemical stain, its clinical significance is unknown. Although most IPTs can be resolved with conservative therapy, surgical resection should be considered in cases of uncertain biopsy result, presumed malignant lesion, combination with other pathology, or lack of response to conservative management.

An imported case of cystic echinococcosis in the liver

A 25-year-old Uzbek male presented with right upper abdominal pain for 20 days. On radiologic studies, a huge cystic mass was noticed in the right liver which was suspected as parasitic. The patient received right hepatic segmentectomy (segment 7), and the surgically resected mass was confirmed as cystic echinococcosis (CE), measuring 10.5 cm in its diameter. The inner surface of the cyst was bile-stained. The patient was discharged on the 8th hospital day, and was rechecked 6 months after the surgical intervention without any evidence of recurrence. The present report describes findings of an imported case of CE which represented ultrasound images of the 'ball of wool'.

Genes associated with recurrence of hepatocellular carcinoma: integrated analysis by gene expression and methylation profiling

Gene expression is suppressed by DNA methylation. The goal of this study was to identify genes whose CpG site methylation and mRNA expression are associated with recurrence after surgical resection for hepatocellular carcinoma (HCC). Sixty-two HCCs were examined by both whole genome DNA methylation and transcriptome analysis. The Cox model was used to select genes associated with recurrence. A validation was performed in an independent cohort of 66 HCC patients. Among fifty-nine common genes, increased CpG site methylation and decreased mRNA expression were associated with recurrence for 12 genes (Group A), whereas decreased CpG site methylation and increased mRNA expression were associated with recurrence for 25 genes (Group B). The remaining 22 genes were defined as Group C. Complement factor H (CFH) and myosin VIIA and Rab interacting protein (MYRIP) in Group A; proline/serine-rich coiled-coil 1 (PSRC1), meiotic recombination 11 homolog A (MRE11A), and myosin IE (MYO1E) in Group B; and autophagy-related protein LC3 A (MAP1LC3A), and NADH dehydrogenase 1 alpha subcomplex assembly factor 1 (NDUFAF1) in Group C were validated. In conclusion, potential tumor suppressor (CFH, MYRIP) and oncogenes (PSRC1, MRE11A, MYO1E) in HCC are reported. The regulation of individual genes by methylation in hepatocarcinogenesis needs to be validated.

Optimal cycle of intermittent portal triad clamping during liver resection in the murine liver

We designed this experimental study to determine the optimal cycle for intermittent inflow occlusion during liver resection. A cycle of intermittent clamping (IC) for 15 minutes of ischemia followed by reperfusion for 5 minutes during liver resection is currently the most popular protocol used by experienced liver centers. As each period of reperfusion is associated with bleeding, longer periods of clamping would be advantageous. However, the longest safe duration of successive ischemia is unknown. Three groups of mice were subjected to a total liver ischemic period for 90 minutes; 2 groups underwent IC for 15 or 30 minutes, respectively, followed by 5 minutes of reperfusion, while the control group was subjected to continuous inflow occlusion only. The degree of tissue injury was assessed using biochemical and histological markers, as well as animal survival. While serious injury was observed in the continuous clamping group, both IC groups were associated with minimal injury, including lesser degrees of apoptosis and necrosis. All animals survived in the IC groups, while all animals died following 90 minutes of continuous inflow occlusion. In conclusion, intermittent portal pedicle clamping with 15- or 30-minute cycles is highly protective. A period of 30 minutes clamping should be preferred, since this would decrease the amount of blood loss associated with each cycle. This data should be confirmed in humans, and may represent a change in the current practice of hepatic surgery.

Laparoscopic appendectomy is feasible for the complicated appendicitis

We reviewed the results of 339 consecutive appendectomies, including perforated appendicitis, to assess the advantages of the laparoscopic approach for acute appendicitis. Three hundred and eighty-eight patients underwent appendectomy at the Keimyung University Kyungju Dongsan Hospital between March 1994 and June 1996; 339 patients were treated using laparoscopic appendectomy (LA), and 49 patients who were treated with open appendectomy. Special emphasis was given to the results of LA in 27 patients with perforated appendicitis. The mean duration of the operating time for LA was 48.9 minutes. For six patients (1.8%), the procedure was converted to open surgery. Minor complications developed in eight patients (2.4%). There were no complications in the 27 patients with perforated appendicitis. Our experience with LA in perforated appendicitis is limited, but our results show that LA is a safe and acceptable procedure for all forms of acute appendicitis.