Response letter to “Acute cholangitis: Does malignant biliary obstruction vs choledocholithiasis etiology change the outcomes?” with imaging aspects

Radiological imaging findings may contribute to the differentiation of malignant biliary obstruction from choledocholithiasis in the etiology of acute cholangitis.

Endoscopic ultrasound-guided biliary drainage using electrocauteryenhanced lumen-apposing metal stent for malignant biliary obstruction:A promising procedure

In this editorial,we comment on the article by Peng et al.Palliative drainage for biliary obstruction resulting from unresectable malignant lesions includes internal and external drainage.The procedures of biliary drainage are usually guided by fluoroscopy or transcutaneous ultrasound,endoscopic ultrasound(EUS),or both.Endoscopic retrograde cholangiopancreatography(ERCP)has been primarily recommended for the management of biliary obstruction,while EUS-guided biliary drainage and percutaneous transhepatic biliary drainage(PTBD)are alternative choices for cases where ERCP has failed or is impossible.PTBD is limited by shortcomings of a higher rate of adverse events,more reinterventions,and severe complications.EUS-guided biliary drainage has a lower rate of adverse events than PTBD.EUS-guided biliary drainage with electrocautery-enhanced lumen-apposing metal stent(ECE-LAMS)enables EUS-guided biliaryenteric anastomosis to be performed in a single step and does not require prior bile duct puncture or a guidewire.The present meta-analysis showed that ECELAMS has a high efficacy and safety in relieving biliary obstruction in general,although the results of LAMS depending on the site of biliary obstruction.This study has highlighted the latest advances with a larger sample-based comprehensive analysis.

Imaging features of malignant vs stone-induced biliary obstruction:Aspects to consider

Radiological studies play a crucial role in the evaluation of patients with biliary duct obstruction,allowing for the guidance of clinical diagnosis towards a malignant or stone-induced etiology through the recognition of relevant imaging features,which must be continuously revisited given their prognostic significance.This article aims to emphasize the importance of recognizing crucial imaging aspects of malignant and stone-induced biliary obstruction.

Role of endoscopic-ultrasound-guided biliary drainage with electrocautery-enhanced lumen-apposing metal stent for palliation of malignant biliary obstruction

In this editorial,we discuss the article by Peng et al in the recent issue of the World Journal of Gastrointestinal Surgery,focusing on the evolving role of endoscopicultrasound-guided biliary drainage(EUS-BD)with electrocautery lumen apposing metal stent(LAMS)for distal malignant biliary obstruction.Therapeutic endoscopy has rapidly advanced in decompression techniques,with growing evidence of its safety and efficacy surpassing percutaneous and surgical approaches.While endoscopic retrograde cholangiopancreatography(ERCP)has been the gold standard for biliary decompression,its failure rate approaches 10.0%,prompting the exploration of alternatives like EUS-BD.This random-effects meta-analysis demonstrated high technical and clinical success of over 90.0% and an adverse event rate of 17.5%,mainly in the form of stent dysfunction.Outcomes based on stent size were not reported but the majority used 6 mm and 8 mm stents.As the body of literature continues to demonstrate the effectiveness of this technique,the challenges of stent dysfunction need to be addressed in future studies.One strategy that has shown promise is placement of double-pigtail stents,only 18% received the prophylactic intervention in this study.We expect this to improve with time as the technique continues to be refined and standardized.The results above establish EUS-BD with LAMS as a reliable alternative after failed ERCP and considering EUS to ERCP upfront in the same session is an effective strategy.Given the promising results,studies must explore the role of EUS-BD as first-line therapy for biliary decompression.

Acute cholangitis: Does malignant biliary obstruction vs choledocholithiasis etiology change the clinical presentation and outcomes?

BACKGROUND Whether clinical outcomes of acute cholangitis(AC)vary by etiology is unclear.AIM To compare outcomes in AC caused by malignant biliary obstruction(MBO)and common bile duct stones(CBDS).METHODS This retrospective study included 516 patients undergoing endoscopic retrograde cholangiopancreatography(ERCP)due to AC caused by MBO(MBO group,n=56)and CBDS(CBDS group,n=460).Clinical and laboratory parameters were compared between the groups.Propensity score matching(PSM)created 55 matched pairs.Confounders used in the PSM analysis were age,sex,time to ERCP,and technical success of ERCP.The primary outcome comparison was 30-d mortality.The secondary outcome comparisons were intensive care unit(ICU)admission rate,length of hospital stay(LOHS),and 30-d readmission rate.RESULTS Compared with the CBDS group,the MBO group had significantly lower body temperature,percentage of abnormal white blood cell counts,and serum levels of aspartate aminotransferase,alanine aminotransferase,and creatinine.Body temperature,percent abnormal white blood cell count,and serum aspartate aminotransferase levels remained significantly lower in the MBO group in the PSM analysis.Platelet count,prothrombin time/international normalized ratio,and serum levels of alkaline phosphatase and total bilirubin were significantly higher in the MBO group.The MBO group had a significantly higher percentage of severe AC(33.9%vs 22.0%,P=0.045)and received ERCP later(median,92.5 h vs 47.4 h,P<0.001).However,the two differences were not found in the PSM analysis.The 30-d mortality(5.4%vs 0.7%,P=0.019),ICU admission rates(12.5%vs 4.8%,P=0.028),30-d readmission rates(23.2%vs 8.0%,P<0.001),and LOHS(median,16.5 d vs 7.0 d,P<0.001)were significantly higher or longer in the MBO group.However,only LOHS remained significant in the PSM analysis.Multivariate analysis revealed that time to ERCP and multiple organ dysfunction were independent factors associated with 30-d mortality.CONCLUSION MBO patients underwent ERCP later and thus had a worse prognosis than CBDS patients.Therefore,clinicians should remain vigilant in MBO patients with clinically suspected AC,and perform ERCP for biliary drainage as soon as possible.

Effectiveness of a new approach to minimally invasive surgery in palliative treatment of patients with distal malignant biliary obstruction

BACKGROUND Palliative endoscopic biliary drainage is the primary treatment option for the management of patients with jaundice which results from distal malignant biliary obstruction(DMBO).In this group of patients,decompression of the bile duct(BD)allows for pain reduction,symptom relief,chemotherapy administration,improved quality of life,and increased survival rate.To reduce the unfavorable effects of BD decompression,minimally invasive surgical techniques require continuous improvement.AIM To develop a technique for internal-external biliary-jejunal drainage(IEBJD)and assess its effectiveness in comparison to other minimally invasive procedures in the palliative treatment of patients with DMBO.METHODS A retrospective analysis of prospectively collected data was performed,which included 134 patients with DMBO who underwent palliative BD decompression.Biliary-jejunal drainage was developed to divert bile from the BD directly into the initial loops of the small intestine to prevent duodeno-biliary reflux.IEBJD was carried out using percutaneous transhepatic access.Percutaneous transhepatic biliary drainage(PTBD),endoscopic retrograde biliary stenting(ERBS),and internal-external transpapillary biliary drainage (IETBD) were used for the treatment of studypatients. Endpoints of the study were the clinical success of the procedure, the frequency andnature of complications, and the cumulative survival rate.RESULTSThere were no significant differences in the frequency of minor complications between the studygroups. Significant complications occurred in 5 (17.2%) patients in the IEBJD group, in 16 (64.0%)in the ERBS group, in 9 (47.4%) in the IETBD group, and in 12 (17.4%) in the PTBD group.Cholangitis was the most common severe complication. In the IEBJD group, the course ofcholangitis was characterized by a delayed onset and shorter duration as compared to other studygroups. The cumulative survival rate of patients who underwent IEBJD was 2.6 times higher incomparison to those of the PTBD and IETBD groups and 20% higher in comparison to that of theERBS group.CONCLUSIONIEBJD has advantages over other minimally invasive BD decompression techniques and can berecommended for the palliative treatment of patients with DMBO.

Unveiling the potential of electrocautery-enhanced lumen-apposing metal stents in endoscopic ultrasound-guided biliary drainage

This editorial delves into Peng et al's article,published in the World Journal of Gastrointestinal Surgery.Peng et al's meta-analysis investigates the effectiveness of electrocautery-enhanced lumen-apposing metal stents(ECE-LAMS)in ultrasound-guided biliary drainage for alleviating malignant biliary obstruction.Examining 14 studies encompassing 620 participants,the research underscores a robust technical success rate of 96.7%,highlighting the efficacy of ECE-LAMS,particularly in challenging cases which have failed endoscopic retrograde cholangio pancreatography.A clinical success rate of 91.0% underscores its impact on symptom alleviation,while a reasonably tolerable adverse event rate of 17.5% is observed.However,the 7.3% re-intervention rate stresses the need for post-procedural monitoring.Subgroup analyses validate consistent outcomes,bolstering the applicability of ECE-LAMS.These findings advocate for the adoption of ECELAMS as an appropriate approach for biliary palliation,urging further exploration in real-world clinical contexts.They offer valuable insights for optimizing interventions targeting malignant biliary obstruction management.

Multicenter study of endoscopic preoperative biliary drainage for malignant distal biliary obstruction

AIM: To determine the optimal method of endoscopic preoperative biliary drainage for malignant distal biliary obstruction.METHODS: Multicenter retrospective study was conducted in patients who underwent plastic stent (PS) or nasobiliary catheter (NBC) placement for resectable malignant distal biliary obstruction followed by surgery between January 2010 and March 2012. Procedure-related adverse events, stent/catheter dysfunction (occlusion or migration of PS/NBC, development of cholangitis, or other conditions that required repeat endoscopic biliary intervention), and jaundice resolution (bilirubin level &#x0003c; 3.0 mg/dL) were evaluated. Cumulative incidence of jaundice resolution and dysfunction of PS/NBC were estimated using competing risk analysis. Patient characteristics and preoperative biliary drainage were also evaluated for association with the time to jaundice resolution and PS/NBC dysfunction using competing risk regression analysis.RESULTS: In total, 419 patients were included in the study (PS, 253 and NBC, 166). Primary cancers included pancreatic cancer in 194 patients (46%), bile duct cancer in 172 (41%), gallbladder cancer in three (1%), and ampullary cancer in 50 (12%). The median serum total bilirubin was 7.8 mg/dL and 324 patients (77%) had &#x02265; 3.0 mg/dL. During the median time to surgery of 29 d [interquartile range (IQR), 30-39 d]. PS/NBC dysfunction rate was 35% for PS and 18% for NBC [Subdistribution hazard ratio (SHR) = 4.76; 95%CI: 2.44-10.0, P &#x0003c; 0.001]; the pig-tailed tip was a risk factor for PS dysfunction. Jaundice resolution was achieved in 85% of patients and did not depend on the drainage method (PS or NBC).CONCLUSION: PS has insufficient patency for preoperative biliary drainage. Given the drawbacks of external drainage via NBC, an alternative method of internal drainage should be explored.

outcomes of preoperative endoscopic nasobiliary drainage and endoscopic retrograde biliary drainage for malignant distal biliary obstruction prior to pancreaticoduodenectomy

AIM to compare the outcomes of preoperative endoscopic nasobiliary drainage (ENBD) and endoscopic retrograde biliary drainage (ERBD) in patients with malignant distal biliary obstruction prior to pancreaticoduodenectomy (PD). METHODS Data from 153 consecutive patients who underwent preoperative endoscopic biliary drainage prior to PD between January 2009 and July 2016 were analyzed. We compared the clinical data, procedure-related complications of endoscopic biliary drainage (EBD) and postoperative complications of PD between the ENBD and ERBD groups. Univariate and multivariate analyses with odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to identify the risk factors for deep abdominal infection after PD. RESULTS One hundred and two (66.7%) patients underwent ENBD, and 51 (33.3%) patients underwent ERBD. Endoscopic sphincterotomy was less frequently performed in the ENBD group than in the ERBD group (P = 0.039); the EBD duration in the ENBD group was shorter than that in the ERBD group (P = 0.036). After EBD, the levels of total bilirubin (TB) and alanine aminotransferase (ALT) were obviously decreased in both groups, and the decreases of TB and ALT in the ERBD group were greater than those in the ENBD group (P = 0.004 and P = 0.000, respectively). However, the rate of EBD procedure-related cholangitis was significantly higher in the ERBD group than in the ENBD group (P = 0.007). The postoperative complications of PD as graded by the Clavien-Dindo classification system were not significantly different between the two groups (P = 0.864). However, the incidence of deep abdominal infection after PD was significantly lower in the ENBD group than in the ERBD group (P = 0.019). Male gender (OR = 3.92; 95% CI: 1.63-9.47; P = 0.002), soft pancreas texture (OR = 3.60; 95% CI: 1.37-9.49; P = 0.009), length of biliary stricture (= 1.5 cm) (OR = 5.20; 95% CI: 2.23-12.16; P = 0.000) and ERBD method (OR = 4.08; 95% CI: 1.69-9.87; P = 0.002) were independent risk factors for deep abdominal infection after PD. CONCLUSION ENBD is an optimal method for patients with malignant distal biliary obstruction prior to PD. ERBD is superior to ENBD in terms of patient tolerance and the effect of biliary drainage but is associated with an increased risk of EBD procedure-related cholangitis and deep abdominal infection after PD. (C) The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.

Biliary stenting with or without sphincterotomy for malignant biliary obstruction:A meta-analysis

AIM: To investigate the benefits of endoscopic sphincterotomy (EST) before stent placement by meta-analysis of randomized controlled trials (RCTs).

Prognostic relevance of circulating CK19 mRNA in advanced malignant biliary tract diseases

AIM: To determine the role of circulating tumor cells (CTCs) in prediction of the overall survival of patients with advanced malignant biliary tract obstruction. METHODS: We investigated the prognostic value of CTCs by examining two markers, cytokeratin (CK) 19 and human telomerase reverse transcriptase (hTERT) mRNA, in 40 patients diagnosed with advanced malig- nant biliary tract diseases. Quantitative real-time re- verse transcription polymerase chain reaction was used to detect CK19 and hTERT mRNA in the peripheral blood of these patients. Overall survival was analyzed using the Kaplan-Meier method and Cox regression modeling.RESULTS: Positive CK19 and hTERT mRNA expression was detected in 45% and 60%, respectively, of the 40 patients. Univariable analysis indicated that positive CK19 mRNA expression was significantly associated with worse overall survival (P = 0.009). Multivariable analysis determined that positive CK19 mRNA expres- sion, patient's age and serum bilirubin were each inde- pendently associated with overall survival. CONCLUSION: CK19 mRNA expression levels in pe- ripheral blood appear to provide a valuable marker to predict the overall survival of patients with advanced malignant biliary tract obstruction.

Folfirinox chemotherapy prolongs stent patency in patients with malignant biliary obstruction due to unresectable pancreatic cancer

Background:Stent insertion for biliary decompression to relieve jaundice and subsequent biliary infection is necessary for patients with biliary obstruction caused by pancreatic cancer,and it is important to keep the stent patent as long as possible.However,few studies have compared stent patency in terms of chemotherapy in patients with pancreatic cancer.This study aimed to evaluate the differences in stent patency in terms of recently evolving chemotherapy.Methods:Between January 2015 and May 2017,161 patients with pancreatic cancer who had undergone biliary stent insertion with a metal stent were retrospectively analyzed.The relationship between chemotherapy and stent patency was assessed.Additionally,overall survival according to the treatment,risk factors for stent patency,and long-term adverse events were evaluated.Results:Median stent patency was 42 days for patients with the best supportive care and 217 days for patients with chemotherapy(conventional gemcitabine-based chemotherapy and folfirinox)(P<0.001).Furthermore,the folfirinox group showed the longest median stent patency and overall survival,with 283 days and 466 days,respectively(P<0.001)despite higher adverse events rate.Patients who underwent folfirinox chemotherapy after stent insertion had better stent patency in multivariate analysis(HR=0.26;95%CI:0.12–0.60;P=0.001).Conclusions:Compared with patients who received best supportive care only,patients who underwent chemotherapy after stent insertion had better stent patency.More prolonged stent patency can be expected for patients with folfirinox than conventional gemcitabine-based chemotherapy.

Predictive factors for the failure of endoscopic stent-instent self-expandable metallic stent placement to treat malignant hilar biliary obstruction

AIM To investigate the factors predictive of failure when placing a second biliary self-expandable metallic stents(SEMSs). METHODS This study evaluated 65 patients with an unresectable malignant hilar biliary obstruction who were examined in our hospital. Sixty-two of these patients were recruited to the study and divided into two groups: the success group, which consisted of patients in whom a stent-in-stent SEMS had been placed successfully, and the failure group, which consisted of patients in whom the stent-in-stent SEMS had not been placed successfully. We compared the characteristics of the patients, the stricture state of their biliary ducts, and the implemented endoscopic retrograde cholangiopancreatography(ERCP) procedures between the two groups.RESULTS The angle between the target biliary duct stricture and the first implanted SEMS was significantly larger in the failure group than in the success group. There were significantly fewer wire or dilation devices(ERCP catheter, dilator, or balloon catheter) passing the first SEMS cell in the failure group than in the success group. The cut-off value of the angle predicting stent-in-stent SEMS placement failure was 49.7 degrees according to the ROC curve(sensitivity 91.7%, specificity 61.2%). Furthermore, the angle was significantly smaller in patients with wire or dilation devices passing the first SEMS cell than in patients without wire or dilation devices passing the first SEMS cell. CONCLUSION A large angle was identified as a predictive factor for failure of stent-in-stent SEMS placement.

Revision of bilateral self-expandable metallic stents placed using the stent-in-stent technique for malignant hilar biliary obstruction

Background: Endoscopic biliary decompression using bilateral self-expandable metallic stent(SEMS) placed using the stent-in-stent(SIS) technique is considered favorable for unresectable malignant hilar biliary obstruction(MHBO). However, occlusion of the bilateral SIS placement is frequent and revision can be challenging. This study was performed to investigate the efficacy, the long-term patency and the appropriate approach for revision of occluded bilateral SIS placement in unresectable MHBO. Methods: From January 2011 to July 2016, thirty-eight patients with unresectable MHBO underwent revision of occluded bilateral SIS placement. Clinical data including success rates and patency of revision, were retrospectively analyzed. Results: The technical success rate of revision was 76.3%. The clinical success rate of revision was 51.7% and mean patency of revision was 49.1 days. No significant predictive factor for clinical failure of revision was observed. The cell size of SEMS was not found to have significant effects on clinical success rates or revision patency. Conclusions: Revision of occluded bilateral SIS placement for MHBO showed fair patency and clinical success rate. Revision method and cell size of SEMS were not found to influence clinical outcomes.

Safety and efficacy of transpapillary bridged bilateral side-by-side stenting for unresectable malignant hilar biliary obstruction

To the Editor:Biliary drainage is most frequently performed among endoscopic procedures using pancreatobiliary endoscopy.A large-diameter metallic stent can significantly extend the patency period rather than a plastic stent for extrahepatic biliary stricture.;However,the optimal drainage for the hilar biliary obstruction is still controversial.

Biliary metal stents should be placed near the hilar duct in distal malignant biliary stricture patients

BACKGROUND Endoscopic biliary drainage using a self-expandable metallic stent(SEMS)has been widely performed to treat distal malignant biliary obstruction(DMBO).However,the optimal position of the stent remains unclear.AIM To determine the ideal position for SEMS placement.METHODS In total,135 DMBO patients underwent SEMS(uncovered or covered)placement over a ten-year period.A total of 127 patients with biliary obstruction between the junction of the cystic duct and Vater’s papilla were enrolled.An SEMS was placed through the upper common bile duct 2 cm from the biliary hilar duct in 83 patients(Hilar group)or near the top of the biliary obstruction in 44 patients(Lower group).Technical and functional success,adverse events,and risk factors for SEMS dysfunction were evaluated.RESULTS The stent patency period was significantly longer in the Hilar group than in the Lower group(P value<0.01).In multivariate analysis,the only statistically significant risk factor for SEMS dysfunction was being in the Lower group(hazard ratio:9.94,95%confidence interval:2.25–44.0,P<0.01).CONCLUSION A longer patency period was achieved by positioning the SEMS near the biliary hilar duct.

Effects of Danshen Injection on the Malignant Obstructive Jaundice in the SD Rat Model

To observe the effects of Danshen on the growth of hepatocellular carcinoma in the SD rats, a model of malignant obstructive jaundice was established by inoculation of transplanted tumor into the hepatic portal with the walker-256 hepatocarcine line, which resulted in the obstruction by the infiltration and metastasis of hepatocellular carcinoma. SD rats were divided into 4 groups： the rats were treated by 0.9 % NS （n=24, control group）, inosine＋vitamin C （n=40, InV group）, Danshen （n=40, DS group） and 5-FU （n=40, 5-FU group）, respectively. The liver function, morphological changes and the expressions of PCNA, VEGF and ICAM-1 in carcinoma foci, peri-carcinoma tissues, adjacent lobe （left-internal lobe） and lung tissues were observed after the treatment with the 4 agents. Our results showed that the protective effect of Danshen on liver function was significantly better than that of NS and 5-FU （P〈0.01）. No significant difference in protective effect was observed between DS group and lnV group （P〉0.05）. Danshen also provided protective effect on the morphological damage of liver caused by obstructive jaundice. The rates of carcinoma-inhibition and metastasis inhibition were significantly higher than those of NS and inosine＋vitamin C （P〈0.01）. No significant difference in this regard existed between DS group and 5-FU group （P〉0.05）. The expressions of PCNA,VEGF and ICAM-1 PCNA, VEGF and ICAM-1 in carcinoma foci, peri-carcinoma tissues, adjacent lobe （left-internal lobe） and lung tissues were lower than those in control group and InV group, with the differences being significant （P〈0.01）. No significant differences were found between DS group and 5-FU group in the expression levels of PCNA and VEGF （P〉0.05） but ICAM-1 （P〈0.05）. It is concluded that Danshen injection not only has protective effects on liver injury caused by obstructive jaundice, but can inhibit the proliferation and growth of hepatocarcinoma, interfere with the vascularization of tumors, prevent recurrence and metastasis of hepatocarcineoma.

Percutaneous insertion of a novel dedicated metal stent to treat malignant hilar biliary obstruction

BACKGROUND Percutaneous bilateral biliary stenting is an established method for the management of unresectable malignant hilar biliary obstruction.AIM To evaluate the efficacy and safety of a novel uncovered biliary stent, specifically designed for hilar reconstruction.METHODS This, single-center, retrospective study included 18 patients(mean age 71 ± 11 years;61.1% male) undergoing percutaneous transhepatic Moving cell stent(MCS) placement for hilar reconstruction using the stent-in-stent technique for malignant biliary strictures, between November 2020 and July 2021. The Patients were diagnosed with cholangiocarcinoma(12/18;66.6%), gallbladder cancer(5/18;27.7%), and colorectal liver metastasis(1/18;5.5%). Primary endpoints were technical(appropriate stent placement) and clinical(relief from jaundice) success. Secondary endpoints included stent patency, overall survival, complication rates and stent-related complications.RESULTS The technical and clinical success rates were 100%(18/18 cases). According to Kaplan-Meier analysis, the estimated overall patient survival was 80.5% and 60.4% at 6 and 12 mo respectively, while stent patency was 90.9% and 68.2% at 6 mo and 12 mo respectively. The mean stent patency was 172.53 ± 56.20 d and median stent patency was 165 d(range 83-315). Laboratory tests for cholestasis significantly improved after procedure: mean total bilirubin decreased from 15.2 ± 6.0 mg/d L to 1.3 ± 0.4 mg/d L(P < 0.001);mean γGT decreased from 1389 ± 832 U/L to 114.6 ± 53.5 U/L(P < 0.001). One periprocedural complication was reported. Stent-related complications were observed in 5 patients(27.7%), including 1 occlusion(5.5%) and 1 stent migration(5.5 %).CONCLUSION Percutaneous hilar bifurcation biliary stenting with the MCS resulted in excellent clinical and technical success rates, with acceptable complication rates. Further studies are needed to confirm these initial positive results.

Comparison of plastic and self-expandable metal stents in the palliative treatment of malignant biliary obstruction: a meta-analysis

Objective： Stent placement is one of the main methods in the palliative treatment of malignant biliary obstruc- tion, including plastic and self-expandable metal stents. The comparison of stent patency between self-expandable metal and plastic stents in palliation of malignant biliary obstruction is meaningful. We carried out a meta-analysis to summarize current evidence for clinical efficacy of self-expandable metal and plastic stents in the treatment of malignant biliary obstruc- tion. Methods： A comprehensive search of several databases including CNKI, Wanfang Data, Sino MED. A fixed-effects or random-effects model was used to pool data of aU study endpoint. Sensitivity analysis was also performed. Results： Eight randomized clinical trials were identified, including 633 patients. These results suggested that the self-expandable metal stents were associated with a significantly longer stent patency （OR = 8.15; 95% CI： 2.80-23.76; 12 = 85%）. No publication bias was observed. Conclusion： Self-expanding metal stents have a longer patency than plastic stents and offer adequate palliation in patients with malignant bUiary obstruction.

Catheter tract implantation metastases associated with percutaneous biliary drainage for extrahepatic cholangiocarcinoma

AIM： To estimate the incidence of catheter tract implantation metastasis among patients undergoing percutaneous transhepatic biliary drainage （PTBD） for extrahepatic cholangiocarcinoma, and to provide data regarding the management of this unusual complication of PTBD by reviewing cases reported in the literature. METHODS： A retrospective analysis of 67 consecutive patients who underwent PTBD before the resection of extrahepatic cholangiocarcinoma was conducted. The median follow-up period after PTBD was 106 too. The English language literature （PubMed, National Library of Medicine, Bethesda, MD, USA）, from .lanuary 1966 through December 2004, was reviewed. RESULTS： Catheter tract implantation metastasis developed in three patients. The cumulative incidence of implantation metastasis reached a plateau （6%） at 20 mo after PTBD. All of the three patients with implantation metastasis died of tumor progression at 3, 9, and 20 mo after the detection of this complication. Among the 10 reported patients with catheter tract implantation metastasis from extrahepatic cholangiocarcinoma （including our three patients）, two survived for more than 5 years after the excision of isolated catheter tract metastases. CONCLUSION： Catheter tract implantation metastasis is not a rare complication following PTBD for extrahepatic cholangiocarcinoma. Although the prognosis for patients with this complication is generally poor, the excision of the catheter tract may enable survival in selected patients with isolated metastases along the catheter tract.