Brief Article Open Access
Copyright ©2013 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Dec 14, 2013; 19(46): 8731-8739
Published online Dec 14, 2013. doi: 10.3748/wjg.v19.i46.8731
Preoperative biliary drainage in patients with hilar cholangiocarcinoma undergoing major hepatectomy
Jun-Jie Xiong, Ai-Lin Wei, Chun-Lu Tan, Xu-Bao Liu, Department of Hepato-Biliary-Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
Quentin M Nunes, NIHR Liverpool Pancreas Biomedical Research Unit, Department of Molecular and Clinical Cancer Medicine, Royal Liverpool University Hospital, University of Liverpool, Liverpool L69 3GA, United Kingdom
Wei Huang, Sichuan Provincial Pancreatitis Center, Department of Integrated Traditional Chinese and Western Medicine, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
Samir Pathak, Department of Hepatobiliary and Transplant Surgery, St James’ University Hospital, Leeds LS9 7TF, United Kingdom
Author contributions: Xiong JJ and Nunes QM contributed equally to this work; Xiong JJ and Nunes QM analyzed the data and wrote the paper; Huang W, Wei AL and Tan CL collected the data; Xiong JJ and Pathak S completed the statistical analysis; Xiong JJ, Nunes QM and Huang W reviewed the manuscript; Liu XB designed the research and reviewed the manuscript.
Correspondence to: Xu-Bao Liu, MD, PhD, Professor, Department of Hepato-Biliary-Pancreatic Surgery, West China Hospital, Sichuan University, Guo Xue Rd 37, Chengdu 610041, Sichuan Province, China. liuxb2011@126.com
Telephone: +86-28-85422474 Fax: +86-28-85422872
Received: August 26, 2013
Revised: October 19, 2013
Accepted: November 1, 2013
Published online: December 14, 2013

Abstract

AIM: To investigate the effect of preoperative biliary drainage (PBD) in jaundiced patients with hilar cholangiocarcinoma (HCCA) undergoing major liver resections.

METHODS: An observational study was carried out by reviewing a prospectively maintained database of HCCA patients who underwent major liver resection for curative therapy from January 2002 to December 2012. Patients were divided into two groups based on whether PBD was performed: a drained group and an undrained group. Patient baseline characteristics, preoperative factors, perioperative and short-term postoperative outcomes were compared between the two groups. Risk factors for postoperative complications were also analyzed by logistic regression test with calculating OR and 95%CI.

RESULTS: In total, 78 jaundiced patients with HCCA underwent major liver resection: 32 had PBD prior to operation while 46 did not have PBD. The two groups were comparable with respect to age, sex, body mass index and co-morbidities. Furthermore, there was no significant difference in the total bilirubin (TBIL) levels between the drained group and the undrained group at admission (294.2 ± 135.7 vs 254.0 ± 63.5, P = 0.126). PBD significantly improved liver function, reducing not only the bilirubin levels but also other liver enzymes. The preoperative TBIL level was significantly lower in the drained group as compared to the undrained group (108.1 ± 60.6 vs 265.7 ± 69.1, P = 0.000). The rate of overall postoperative complications (53.1% vs 58.7%, P = 0.626), reoperation rate (6.3% vs 6.5%, P = 1.000), postoperative hospital stay (16.5 vs 15.0, P = 0.221) and mortality (9.4% vs 4.3%, P = 0.673) were similar between the two groups. In addition, there was no significant difference in infectious complications (40.6% vs 23.9%, P = 0.116) and noninfectious complications (31.3% vs 47.8%, P = 0.143) between the two groups. Univariate and multivariate analyses revealed that preoperative TBIL > 170 μmol/L (OR = 13.690, 95%CI: 1.275-147.028, P = 0.031), Bismuth-Corlette classification (OR = 0.013, 95%CI: 0.001-0.166, P = 0.001) and extended liver resection (OR = 14.010, 95%CI: 1.130-173.646, P = 0.040) were independent risk factors for postoperative complications.

CONCLUSION: Overall postoperative morbidity and mortality rates after major liver resection are not improved by PBD in HCCA patients with jaundice. Preoperative TBIL > 170 μmol/L, Bismuth-Corlette classification and extended liver resection are independent risk factors linked to postoperative complications.

Key Words: Obstructive jaundice, Hilar cholangiocarcinoma, Preoperative biliary drainage, Major hepatectomy, Surgical outcome

Core tip: There is currently no consensus on the use of preoperative biliary drainage (PBD) in jaundiced patients with hilar cholangiocarcinoma undergoing major liver resection. We retrospectively analyzed prospectively maintained database of these patients who underwent PBD or not. The baseline characteristics, perioperative and short-term postoperative outcomes between these two groups were compared and no significant differences were identified. We found that a preoperative total bilirubin level > 170 μmol/L, Bismuth-Corlette classification and extended liver resection are three independent risk factors for postoperative complications. There is a need to undertake well-designed, prospective multicenter studies to inform future practice.



INTRODUCTION

Hilar cholangiocarcinoma (HCCA), which was first defined by Klatskin[1] as an adenocarcinoma of the hepatic duct at its bifurcation within the porta hepatis, is associated with a poor prognosis[1,2]. Currently, the only curative treatment is radical surgical resection[3]. However, a R0 resection margin is difficult to achieve because the tumor often infiltrates the portal vein, the hepatic artery and liver parenchyma[4,5]. In order to obtain negative histological margins and improve survival, many surgeons have adopted a more aggressive surgical approach, namely, extended hepatectomy combined with portal vein or hepatic artery resection and reconstruction, and hepato pancreaticoduodenectomy for the treatment of this malignancy[6-8]. However, the majority of patients with HCCA have obstructive jaundice at presentation, which increases the risk of complications, such as sepsis, bleeding and liver failure, especially in patients undergoing major hepatectomy[9,10]. Therefore, preoperative biliary drainage (PBD) was introduced with the aim to abrogate these potential complications in patients with jaundice secondary to HCCA, despite that a consensus on an appropriate cut-off level of total bilirubin (TBIL)[11-14] and duration of drainage[8,15,16] has not been reached yet.

There is still controversy with regard to whether PBD is essentially needed for jaundiced patients with HCCA undergoing major liver resection. It was shown that PBD reverses cholestasis-associated hepatic and systemic toxicity, and improves liver function, nutritional status and cell-mediated immune function[17]. However, concerns were also raised as PBD may associate with an increased incidence of postoperative morbidity and mortality[18-20], although this was not the case for other studies[21,22]. Recently, one multicenter European study including patients undergoing major liver resection for HCCA suggested that overall morbidity was not affected by PBD procedure[14]. Furthermore, preoperative portal vein embolization (PVE), which is restricted to the treatment of postoperative inadequate residual liver volume and induces hypertrophy of the future remnant liver, has led to a change to PBD strategy[23]. PBD followed by PVE prior to major hepatectomy is considered a safe management strategy for HCCA, particularly in patients with remnant liver volume less than 40%[24-26].

The aim of this study was to inform the debate by comparing the perioperative and short-term postoperative outcomes of jaundiced patients with HCCA undergoing curative major liver resection with or without PBD, at a large specialist center in China.

MATERIALS AND METHODS
Study population and preoperative management

The prospectively maintained database for a cohort of consecutive HCCA patients treated at the West China Hospital of Sichuan University between January 2002 and December 2012 was retrospectively reviewed. From the database, only patients with HCCA who had jaundice and underwent major hepatectomy for curative resection were included in this study. Jaundice was defined as a serum TBIL level > 85.5 μmol/L (5 mg/dL). HCCA was defined as lesions arising from the common hepatic duct, left, right, or both hepatic duct and intrahepatic bile duct cancer invading the hepatic hilus[11]. The tumors were classified according to Bismuth-Corlette classification[27].

In our series, blood sampling for serum biochemistry was completed 2-3 d before drainage or surgery. Color Doppler ultrasound and contrast enhanced computed tomography (CT) were used routinely before surgery. Furthermore, magnetic resonance imaging (MRI) was used in most of patients. If distant metastases were suspected, further investigations with positron emission tomography-CT scan were performed. PVE was carried out at our hospital if the remnant liver volume post surgical resection was expected to be less than 50% of the whole liver volume. PBD was performed if patients fulfilled one of the following criteria: duration of jaundice of more than 4 wk; poor nutritional status (serum albumin < 3 g/dL); signs of cholangitis. PBD procedures in our center were percutaneous transhepatic cholangio-drainage (PTCD), endoscopic biliary stenting (EBS), endoscopic nasobiliary drainage (ENBD) and/or surgical drainage. For patients who had inadequate PBD before admission to our hospital, a further drainage by a percutaneous approach was adapted. Adequate PBD was evident by a relief of cholangitis, and an improvement in the liver function and/or the nutritional status of the patient.

Surgical procedures

At our center, curative excision was defined as histologically negative surgical margins with a minimum tumor-free margin of 5 mm at the hepatic stump of the bile duct, the duodenal stump of the bile duct, and the excision surface. It included resection of the gallbladder and extrahepatic bile duct; skeletonization of the vasculature of the hepatoduodenal ligament; and partial hepatectomy, or even removal of the caudate lobe or portal vein or hepatic artery as required. The postoperative biliary drainage was established by a Roux-en-Y hepaticojejunostomy. Major hepatectomy was defined as resection of three or more Couinaud segments. Caudate lobectomy was performed in patients in whom it was considered necessary to achieve complete tumor clearance.

Postoperative complications

While patients were followed routinely after discharge from hospital, as part of this study, we endeavored to investigate the effect of PBD on in-hospital postoperative outcomes. Hence, postoperative mortality was defined as death prior to hospital discharge. All postoperative complications were defined as events that lengthened hospital stay. Infectious complications were defined according to the study by Hochwald et al[19]; these were intraabdominal abscess, wound infection, cholangitis, sepsis and lung infection. Noninfectious complications included liver failure, bile leak, anastomotic leak, abdominal collection, gastrointestinal bleeding, abdominal bleeding, respiratory failure and renal failure. Liver failure was defined as an increased international normalized ratio and concomitant hyperbilirubinemia on or after postoperative day five[28]. Bile leak was defined as the drainage of 50 mL or more of bile from the surgical drain or from drainage of an abdominal collection, over a period of three days or more[29]. In addition, the complications were graded according to the Clavien-Dindo classification of surgical complications[30].

Literature search

Existing literature was also reviewed by performing a systematic search in PubMed, Medline and Embase from January 1990 to May 2013. The following search terms were used: “preoperative biliary drainage” or “percutaneous transhepatic biliary drainage” or “endoscopic biliary drainage” or “endoscopic nasobiliary drainage” or “endoscopic biliary stenting” and ‘‘hilar cholangiocarcinoma’’ or “hilar bile duct cancer’’ or ‘‘proximal bile duct cancer’’ or “Klatskin tumor’’ or ‘‘carcinoma of the hepatic duct confluence’’ along with their synonyms or abbreviations. The search was restricted to studies conducted on human subjects and in the English language only.

Statistical analysis

Data are presented as mean ± SD or median and interquartile range. The χ2 test or Fisher’s exact test or RxC table analysis was used to compare categorical variables, and the Student’s t test or Mann-Whitney U test was used to compare continuous variables. A statistically significant difference was defined as a P value < 0.05. The variables of statistical significance during univariate analysis were included in a follow-up multivariate analysis, by using the logistic regression test. The OR and 95%CI were also calculated for individual factors in the multivariate analysis. All statistical analyses were performed with SPSS software (SPSS version 17.0, Chicago, Illinois).

RESULTS
Baseline characteristics

During the study period, 78 patients with jaundice underwent major hepatic resection for HCCA at our hospital. There were 32 patients in the drained (PBD) group and 46 patients in the undrained (no PBD) group. The baseline characteristics of patients are outlined in Table 1. The drained group was comparable with the undrained group with regards to age, sex, body mass index, comorbidity and previous history of abdominal surgery (P > 0.05 for all). Nine patients in the PBD group had previous abdominal surgery that included 5 cholecystectomies and 4 common bile duct explorations with T-tube drainage. Twelve patients in the undrained group had previous abdominal surgery, which included 6 appendectomies, 4 cholecystectomies and 2 cholecystectomies with common bile duct exploration. Furthermore, there was no significant difference in the TBIL levels at admission between the drained and undrained groups (294.2 ± 135.7 vs 254.0 ± 63.5, P = 0.126).

Table 1 Baseline characteristics n (%).
Drained (n = 32)Undrained (n = 46)P value
Age (yr)59.6 ± 11.058.2 ± 11.30.568
Sex (M/F)21/1128/180.669
Body mass index (kg/m2)20.3 ± 1.921.0 ± 2.50.190
Concomitant diseases
Diabetes2 (6.3)3 (6.5)1.000
Hypertension3 (9.4)7 (15.2)0.678
Cardiovascular2 (6.3)5 (10.9)0.765
Previous history of abdominal surgery9 (28.1)12 (26.1)0.842
Serum total bilirubin (μmol/L)
At admission294.2 ± 135.7254.0 ± 63.50.126
Before surgery108.1 ± 60.6265.7 ± 69.10.000
Time of PBD (d)15.3 ± 3.4--
Time between admission and surgery (d)20.7 ± 2.13.8 ± 1.60.000
Portal vein embolization5 (15.6)3 (6.5)0.355
Bismuth–Corlette classification
I1 (3.1)1 (2.2)1.000
II8 (25)14 (30.4)0.600
IIIa6 (18.8)7 (15.2)0.680
IIIb9 (28.1)15 (32.6)0.673
IV8 (25)9 (19.6)0.567
Perioperative details
Hilar bile duct resection32 (100)46 (100)-
Left hepatectomy17 (53.1)31 (67.4)0.203
Extended left hepatectomy2 (6.3)1 (2.2)0.747
Right hepatectomy8 (25)10 (21.7)0.737
Extended right Hepatectomy5 (15.6)4 (8.7)0.561
Caudate lobectomy8 (25)12 (26.1)0.914
Pedicle clamping17 (53.1)26 (56.5)0.767
Portal vein resection6 (18.8)8 (17.4)0.878
Hepatic artery resection2 (6.3)3 (6.5)1.000
Number of blood Transfusions11 (34.4)24 (52.2)0.120
Intraoperative blood transfusion (mL)900 (800-900)800 (600-1100)0.513
PBD techniques and liver function tests

In the PBD group, 23, 5 and 4 patients underwent PTCD, ENBD, and surgical drainage, respectively. In this study, 4 patients underwent surgical drainage through laparotomy and T-tube placement at the referring hospitals. No patient in this study underwent EBS. Six patients underwent PTCD twice each as a result of previous inadequate drainage. Drainage-related complications occurred in 8 patients (10.3%), with 3 cases of cholangitis and 4 of hemobilia following PTCD, and 1 case of hyperamylasemia following ENBD. All these adverse events were resolved after symptomatic treatment alone before surgery. The mean time between insertion of a biliary drainage catheter preoperatively and surgical resection was 15.3 ± 3.4 (d). PBD significantly improved liver function as evidenced by reduced TBIL (294.2 ± 135.7 vs 108.1 ± 60.6, P = 0.000), direct bilirubin (DBIL) (231.8 ± 87.0 vs 85.2 ± 57.4, P = 0.000), aspartate aminotransferase (AST) (132.1 ± 68.6 vs 86.1 ± 35.8, P = 0.000), alanine aminotransferase (ALT) (123.2 ± 79.1 vs 97.5 ± 62.4, P = 0.004), gamma-glutamyl transpeptidase (GGT) (531.2 ± 434.7 vs 357.6 ± 268.3, P = 0.000) and alkaline phosphatase (ALP) (502.1 ± 356.2 vs 343.5 ± 187.6, P = 0.001), although albumin (ALB) (36.7 ± 4.8 vs 34.8 ± 5.9, P = 0.213) levels remained unchanged.

Perioperative details

All patients in both groups had hilar bile duct resection. There were no significant differences in operation procedure (liver resection) between the two groups. Also, there were no significant differences between the drained and undrained groups in terms of caudate lobectomy, pedicle clamping, portal vein resection, hepatic artery resection, number of patients requiring blood transfusions and intraoperative blood transfusion volume (all P > 0.05).

Postoperative outcomes

Postoperative outcomes are outlined in Table 2. The number of patients with postoperative morbidity in the two groups was comparable (53.1% vs 58.7%, P = 0.626). No significant difference was found in the number of patients who had either infectious morbidity or non-infectious morbidity. Also, there was no significant difference in the incidence of individual complications. In addition, in a subgroup analysis (data not shown in table), there was a higher morbidity (84.6% vs 35.7%, P = 0.028) in patients undergoing right-sided hepatectomy without PBD than patients with PBD. However, in the left-sided hepatectomy group, patients had a higher morbidity (78.9% vs 40.6%, P = 0.018) in the drained group compared to the undrained group. However, there was no difference in the postoperative hospital stay between the two groups (16.5 vs 15, P = 0.221). Two patients in the drained group and 3 patients in the undrained group underwent reoperation. There was no significant difference in mortality (9.4% vs 4.3%, P = 0.673) between the two groups. In the drained group, 1 patient died of multiorgan failure (liver failure and renal failure) while another 2 patients died of septic shock. In the undrained group, one patient died from a massive gastrointestinal bleeding while another 1 patient died of multiorgan failure (liver failure and renal failure).

Table 2 Postoperative outcomes of patients undergoing major hepatectomy n (%).
Drained (n = 32)Undrained (n = 46)P value
Morbidity17 (53.1)27 (58.7)0.626
Infectious morbidity13 (40.6)11 (23.9)0.116
Intra-abdominal abscess (II-IIIa)3 (9.4)2 (4.3)0.673
Wound infection (I-IIIb)4 (12.5)4 (8.7)0.869
Cholangitis (II)1 (3.1)2 (4.3)1.000
Sepsis (IVa-V)2 (6.3)1 (2.2)0.747
Lung infection (II)6 (18.8)5 (10.9)0.325
Noninfectious morbidity10 (31.3)22 (47.8)0.143
Liver failure (II-V)3 (9.4)6 (13)0.890
Bile leak
Remnant liver1 (II-IIIa)2 (6.3)4 (8.7)1.000
Anastomotic leak2 (II-IIIb)1 (3.1)2 (4.3)1.000
Abdominal collection (I-IIIa)6 (18.8)9 (19.6)0.928
Gastrointestinal bleeding (IIIa-V)02 (4.3)0.510
Abdominal bleeding (II-IIIb)1 (3.1)2 (4.3)1.000
Respiratory failure (IVa)03 (6.5)0.265
Renal failure (IVa-V)3 (9.4)4 (8.7)1.000
Mortality (V)3 (9.4)2 (4.3)0.673
Reoperation2 (6.3)3 (6.5)1.000
Postoperative hospital stay (d)16.5 (13.5-20.5)15 (12-18)0.221
Logistic regression analyses

Several variables in this study were analyzed for their association with postoperative morbidity (Table 3). Univariate logistic regression showed that PBD was not a risk factor associated with postoperative morbidity. However, preoperative TBIL > 170 μmol/L (P = 0.021), preoperative AST > 100 U/L (P = 0.036), Bismuth-Corlette classification (P = 0.025) and extended liver resection (P = 0.018) were risk factors associated with postoperative morbidity on univariate logistic regression analysis. Furthermore, multivariate analysis identified preoperative TBIL > 170 μmol/L (OR = 13.690, 95%CI: 1.275-147.028, P = 0.031), Bismuth-Corlette classification (OR = 0.013, 95%CI: 0.001-0.166, P = 0.001) and extended liver resection (OR = 14.010, 95%CI: 1.130-173.646, P = 0.040) as three independent risk factors for postoperative complications.

Table 3 The risk factors for postoperative complications n (%).
VariablenIncidence of complicationsUnivariateMultivariate
P valueORP value
Age (yr)
> 603821 (55.3)0.842
≤ 604023 (57.5)
Sex
Male4925 (51)0.212
Female2919 (65.5)
PBD
Yes3217 (53.1)0.626
No4627 (58.7)
Concomitant diseases
Yes2014 (70)0.155
No5830 (51.7)
Previous abdominal surgery
Yes2111 (52.4)0.663
No5733 (57.9)
Preoperative TBIL
> 170 μmol/L4832 (66.7)0.02113.690 (1.275-147.028)0.031
≤ 170 μmol/L3012 (40)
Preoperative AST
> 100 U/L4731 (66)0.0361.138 (0.157-8.225)0.898
≤ 100 U/L3113 (41.9)
Preoperative ALT
> 100 U/L4429 (65.9)0.0545.664 (0.595-53.905)0.131
≤ 100 U/L3415 (44.1)
Preoperative ALB
> 354126 (63.4)0.189
≤ 353718 (48.6)
Bismuth–Corlette stage
I and II249 (37.5)0.0250.013 (0.001-0.166)0.001
III and IV5435 (64.8)
Extended liver resection
Yes1211 (91.7)0.01814.010 (1.130-173.646)0.04
No6633 (50)
Caudate lobectomy
Yes2012 (60)0.707
No5832 (55.2)
Pedicle clamping
Yes4322 (51.2)0.300
No3522 (62.9)
Vascular resections
Yes1913 (68.4)0.225
No5931 (52.5)
Additional surgery
Yes63 (50)0.742
No7241 (56.9)
Intraoperative blood transfusion
Yes3519 (54.3)0.644
No4325 (59.5)
Results of literature search

Fourteen studies were identified[5,10,14,18-20,31-37] using the defined search strategy (Table 4). Seven studies included patients who had curative resections only[5,14,18,20,31,33,37], while the remaining studies included both curative and palliative resection groups.

Table 4 Studies including resections for hilar cholangiocarcinoma with and without preoperative biliary drainage n (%).
Ref.YearCountryDesignType of PBDSurgical procedures for included patientsPBDnMorbidityP valueMortalityP value
Su et al[10]1996ChinaRetroPTCDCR and PRYes3317 (51.5)NS5 (15.2)NS
No166 (37.5)0
Takada et al[37]1996JapanRetroPTCDCRYes24NA-3 (12.5)NS
No12NA6 (50)
Hochwald et al[19]1999United StatesProPTCDCR and PRYes4236 (85.7)0.0452 (4.8)NS
EBDNo2919 (65.5)4 (14.3)
Figueras et al[31]2000SpainRetroPTCDCRYes1111 (100)NS1 (9)NS
No96 (66)2 (22.2)
Parks et al[36]2000United KingdomRetroPTCDCR and PRYes2011 (55)NS1 (5)NS
EBDNo2711 (40.7)1 (3.7)
Gerhards et al[5]2000The NetherlandsRetroPTCDCRYes9359 (63)NS16 (17)NS
EBDNo1813 (72)3 (17)
Dinant et al[33]2006The NetherlandsRetroPTCDCRYes8356 (67.5)NS14 (16.7)NS
EBDNo146 (42.9)2 (14.3)
Li et al[32]2009ChinaRetroPTCDCR and PRYes5520 (36.3)NS4 (7.3)NS
No5616 (28.6)5 (8.9)
Ferrero et al[18]2009ItalyRetroPTCDCRYes3021 (70)NS1 (3)NS
EBDNo3019 (63)3 (10)
SD
Ercolani et al[34]2010ItalyRetroPTCDCR and PRYes4425 (56.8)NSNA-
EBDNo72 (28.5)NA
El-Hanafy et al[20]2010EgyptRetroPTCDCRYes4627 (58.6)0.0015 (10.8)NS
EBDNo5411 (20.3)3 (5.5)
Yu et al[35]2012ChinaRetroPTCD with bile re-infusionCR and PRYes4814 (29.2)0.0361 (2.1)NS
No3920 (51.3)2 (5.1)
Farges et al[14]2013France and BelgiumRetroPTCDCRYes180123 (68.3)NS17 (9.4)NS
EBDNo186128 (68.8)22 (11.8)
Present studyChinaRetroPTCDCRYes3217 (53.1)NS3 (9.4)NS
EBDNo4627 (58.7)2 (4.3)
SD
DISCUSSION

Currently, the only curative treatment for HCCA is radical surgical resection[3]. Patients with HCCA usually present with concomitant obstructive jaundice, which results in high surgical morbidity and mortality in those undergoing major hepatic resection[38,39]. Furthermore, postoperative liver failure is a common cause of in-hospital death after major hepatectomy in patients with obstructive jaundice[13,40]. PBD offers the advantage of being able to increase the tolerance of cholestatic liver to ischemia, improve the regeneration capacity of the liver and decrease blood loss, which may contribute to reducing morbidity and mortality. However, there were conflicting conclusions from various studies with regards to the benefits of PBD[14,19,20,31,35,41].

In our study, the two groups were comparable with respect to demographics, BMI, comorbidities and serum TBIL levels at admission. PBD-associated complications were low, occurring in 8 patients (10.3%), which may be because EBS was not used in our study[42]. This also illustrates that the drainage techniques and technology used at our center are feasible. The number of patients undergoing PVE before surgery was comparable between the drained and undrained groups. PBD followed by PVE prior to major hepatectomy is considered a safe management strategy[24-26].

The number of patients with postoperative complications was comparable, with 17 patients (53.1%) in the drained group and 27 patients (58.7%) in the undrained group; there was no significant difference in the number of patients who had either infectious complications or non-infectious complications. We found this result to be consistent with most of the studies that were reviewed in our systematic search. Most recently, a multicenter European study by Farges et al[14] reported that there was no significant difference in the rate of complications between drained and undrained groups of patients undergoing major liver resection. However, the infectious complications were not compared in this study and the risk factors for the overall complications were not analyzed. In our study, there was no significant difference in the number of patients with infectious complications between the two groups, which might be because most of them underwent PTCD (71.9%) as compared to endoscopic techniques (ENBD-15.6% and EBS-0%). EBS in particular has been shown to increase the infectious complication rate as compared to other drainage procedures[18,23,42,43]. Three studies[18-20] from our search reported higher infectious complications in patients who underwent PBD. Four studies[5,18,19,31] reported no significant difference in the non-infectious complication rates between the two groups. In our study, patients undergoing right-sided hepatectomy without PBD had a higher morbidity than patients with PBD, whereas contrary results were obained in the left-sided hepatectomy group. This is consistent with the study carried out by Farges et al[14]. Furthermore, while some studies have reported a longer stay in the drained group[20,31], other studies have shown no difference between the two groups[18,19]. In our study, there was no difference in the postoperative hospital stay, reoperation rate and mortality between the two groups.

While PBD was not a risk factor for postoperative complications, preoperative TBIL > 170 μmol/L, a higher Bismuth-Corlette classification and extended liver resection were found to be three independent risk factors for postoperative complications. In our study, PBD reduced the preoperative serum bilirubin level and other liver function indexes significantly as compared to those on admission. However, this did not translate into a significant reduction in the occurrence of postoperative complications, as compared to the undrained group. Previous studies have shown that preoperative bilirubin levels influence postoperative morbidity and mortality rates[18,34]. However, there is no consensus on the serum bilirubin cut-off level before surgery at which PBD should be undertaken. Some studies recommend undertaking PBD at a bilirubin cut-off of 51.3 μmol/L (3 mg/dL) to minimize complications following major surgery[11,12]. Other studies recommend a bilirubin cut-off of more than 85.5 μmol/L (5 mg/dL)[13]. The serum bilirubin level prior to surgery was 108.1 ± 60.6 μmol/L in our study. Farges et al[14] advised that major hepatectomy for jaundiced patients should be delayed until the serum bilirubin level had fallen below 50 μmol/L. Other studies have suggested that PBD should be performed and surgery should be delayed when the preoperative bilirubin level was higher than 171 μmol/L (10 mg/dL)[10,34]. Koyama et al[15] advised that adequate recovery of hepatic function depended not only on the duration of obstructive jaundice prior to decompression, but also on the duration of biliary decompression. Some studies have suggested 3-6 wk of preoperative drainage for obstructive jaundice, with even longer periods proposed with a prolonged biliary obstruction before decompression[8,15,16]. In our study, the PBD catheter remained in situ for a mean of 15.3 d. In light of the above, it is plausible that postoperative outcomes may have improved further, had we kept the PBD catheter in situ longer with a lower preoperative serum bilirubin level. However, we recommend PBD, prior to major hepatectomy, in patients with HCCA with a TBIL above 170 μmol/L.

Gerhards et al[5] had reported a higher Bismuth-Corlette classification was associated with postoperative morbidity. Also Li et al[32] reported that while PBD alleviated liver injury caused by hyperbilirubinemia, it did not decrease the postoperative morbidity and mortality and concomitant hepatectomy and Bismuth-Corlette classification were independent risk factors linked to surgical risks. This is explainable as a higher Bismuth-Corlette classification warrants a more extensive surgical resection, which resulted in higher morbidity[44]. Indeed, in our study, there were many patients with stage III and IV tumors who underwent extended hepatectomy with caudate lobe resection and vascular resection.

We acknowledge the limitations of our study. First of all, our results derive from a retrospective study and are unavoidably subject to selection bias although a consecutive series was reported. Second, the sample size is relatively small, coming from a single center. Moreover, various factors such as the variable procedures for biliary drainage, treatment of patients at other centers prior to transfer to our center and failure of the initial drainage procedure may have contributed to biases in our study. However, as the baseline characteristics of patients prior to surgery were comparable between the drained and undrained groups, we hope that the effect of these factors on postoperative outcome was minimized. Currently, there continues to be a lack of consensus and recommendations on the use of PBD prior to major liver resection for HCCA. This has been highlighted by our study and review of literature. While an adequately powered randomized controlled trial at a single center may be currently unrealistic, in view of the rarity of this tumor, a multicenter study would go a long way in informing future practice.

In summary, short-term postoperative outcomes after major liver resection for HCCA are not improved by PBD, which is consistent with most of published evidence. Preoperative TBIL > 170 μmol/L and Bismuth-Corlette classification and extended liver resection might be three independent risk factors for postoperative complications. There is a need to undertake multicenter studies to inform future practice.

COMMENTS
Background

Whether preoperative biliary drainage (PBD) should be used in jaundiced patients with hilar cholangiocarcinoma (HCCA) undergoing major liver resection remains unclear.

Research frontiers

To investigate the role of PBD in patients with HCCA undergoing major liver hepatectomy using prospectively maintained database from a specialty center. A retrospective comparative analysis was performed comparing the perioperative and short-term postoperative outcomes of patients with PBD or not.

Innovations and breakthroughs

Based on the study, PBD does not improve short-term postoperative outcomes in patients with HCCA undergoing major liver resection. However, Preoperative total bilirubin (TBIL) > 170 μmol/L, Bismuth-Corlette classification and extended liver resection are three independent risk factors for postoperative complications.

Applications

The advantages of PBD was not found in this study; however, higher preoperative TBIL (> 170 μmol/L) was indeed a risk factor for postoperative complications. In addition, taking into account the nature of a retrospective study, there is a need to undertake well-designed, prospective multicenter studies to inform future practice.

Terminology

PBD is an important method for recovery of liver function in patients with obstructive jaundice, which includes the percutaneous transhepatic cholangio-drainage, endoscopic biliary stenting, endoscopic nasobiliary drainage and surgical drainage.

Peer review

This well-written study investigated the short-time postoperative outcomes and risk factors in jaundiced patients as result of HCCA with PBD or not. It may be of interest for hepatobiliary surgeons worldwide.

Footnotes

P- Reviewers: Nakazawa T, Regimbeau JM, Schaap FG S- Editor: Cui XM L- Editor: Wang TQ E- Editor: Zhang DN

References
1.  Klatskin G. Adenocarcinoma of the hepatic duct at its bifurcation within the porta hepatis. An unusual tumor with distinctive clinical and pathological features. Am J Med. 1965;38:241-256.  [PubMed]  [DOI]  [Cited in This Article: ]
2.  Liu F, Li Y, Wei Y, Li B. Preoperative biliary drainage before resection for hilar cholangiocarcinoma: whether or not? A systematic review. Dig Dis Sci. 2011;56:663-672.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 80]  [Cited by in F6Publishing: 72]  [Article Influence: 5.5]  [Reference Citation Analysis (0)]
3.  Kondo S, Takada T, Miyazaki M, Miyakawa S, Tsukada K, Nagino M, Furuse J, Saito H, Tsuyuguchi T, Yamamoto M. Guidelines for the management of biliary tract and ampullary carcinomas: surgical treatment. J Hepatobiliary Pancreat Surg. 2008;15:41-54.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 146]  [Cited by in F6Publishing: 153]  [Article Influence: 9.6]  [Reference Citation Analysis (0)]
4.  Belghiti J, Ogata S. Preoperative optimization of the liver for resection in patients with hilar cholangiocarcinoma. HPB (Oxford). 2005;7:252-253.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 46]  [Cited by in F6Publishing: 49]  [Article Influence: 2.6]  [Reference Citation Analysis (0)]
5.  Gerhards MF, van Gulik TM, de Wit LT, Obertop H, Gouma DJ. Evaluation of morbidity and mortality after resection for hilar cholangiocarcinoma--a single center experience. Surgery. 2000;127:395-404.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 136]  [Cited by in F6Publishing: 149]  [Article Influence: 6.2]  [Reference Citation Analysis (0)]
6.  Nagino M, Kamiya J, Arai T, Nishio H, Ebata T, Nimura Y. “Anatomic” right hepatic trisectionectomy (extended right hepatectomy) with caudate lobectomy for hilar cholangiocarcinoma. Ann Surg. 2006;243:28-32.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 110]  [Cited by in F6Publishing: 117]  [Article Influence: 6.5]  [Reference Citation Analysis (0)]
7.  Miyazaki M, Kato A, Ito H, Kimura F, Shimizu H, Ohtsuka M, Yoshidome H, Yoshitomi H, Furukawa K, Nozawa S. Combined vascular resection in operative resection for hilar cholangiocarcinoma: does it work or not? Surgery. 2007;141:581-588.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 179]  [Cited by in F6Publishing: 170]  [Article Influence: 10.0]  [Reference Citation Analysis (0)]
8.  Seyama Y, Kubota K, Sano K, Noie T, Takayama T, Kosuge T, Makuuchi M. Long-term outcome of extended hemihepatectomy for hilar bile duct cancer with no mortality and high survival rate. Ann Surg. 2003;238:73-83.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 176]  [Cited by in F6Publishing: 239]  [Article Influence: 11.4]  [Reference Citation Analysis (1)]
9.  Belghiti J, Hiramatsu K, Benoist S, Massault P, Sauvanet A, Farges O. Seven hundred forty-seven hepatectomies in the 1990s: an update to evaluate the actual risk of liver resection. J Am Coll Surg. 2000;191:38-46.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 800]  [Cited by in F6Publishing: 778]  [Article Influence: 32.4]  [Reference Citation Analysis (0)]
10.  Su CH, Tsay SH, Wu CC, Shyr YM, King KL, Lee CH, Lui WY, Liu TJ, P’eng FK. Factors influencing postoperative morbidity, mortality, and survival after resection for hilar cholangiocarcinoma. Ann Surg. 1996;223:384-394.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 208]  [Cited by in F6Publishing: 209]  [Article Influence: 7.5]  [Reference Citation Analysis (0)]
11.  Nimura Y, Hayakawa N, Kamiya J, Kondo S, Shionoya S. Hepatic segmentectomy with caudate lobe resection for bile duct carcinoma of the hepatic hilus. World J Surg. 1990;14:535-543; discussion 544.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 336]  [Cited by in F6Publishing: 311]  [Article Influence: 9.1]  [Reference Citation Analysis (0)]
12.  Makuuchi M, Thai BL, Takayasu K, Takayama T, Kosuge T, Gunvén P, Yamazaki S, Hasegawa H, Ozaki H. Preoperative portal embolization to increase safety of major hepatectomy for hilar bile duct carcinoma: a preliminary report. Surgery. 1990;107:521-527.  [PubMed]  [DOI]  [Cited in This Article: ]
13.  Hemming AW, Reed AI, Fujita S, Foley DP, Howard RJ. Surgical management of hilar cholangiocarcinoma. Ann Surg. 2005;241:693-699; discussion 693-699.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 258]  [Cited by in F6Publishing: 239]  [Article Influence: 12.6]  [Reference Citation Analysis (0)]
14.  Farges O, Regimbeau JM, Fuks D, Le Treut YP, Cherqui D, Bachellier P, Mabrut JY, Adham M, Pruvot FR, Gigot JF. Multicentre European study of preoperative biliary drainage for hilar cholangiocarcinoma. Br J Surg. 2013;100:274-283.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 142]  [Cited by in F6Publishing: 153]  [Article Influence: 12.8]  [Reference Citation Analysis (0)]
15.  Koyama K, Takagi Y, Ito K, Sato T. Experimental and clinical studies on the effect of biliary drainage in obstructive jaundice. Am J Surg. 1981;142:293-299.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 126]  [Cited by in F6Publishing: 119]  [Article Influence: 2.8]  [Reference Citation Analysis (0)]
16.  Kawarada Y, Higashiguchi T, Yokoi H, Vaidya P, Mizumoto R. Preoperative biliary drainage in obstructive jaundice. Hepatogastroenterology. 1995;42:300-307.  [PubMed]  [DOI]  [Cited in This Article: ]
17.  van der Gaag NA, Kloek JJ, de Castro SM, Busch OR, van Gulik TM, Gouma DJ. Preoperative biliary drainage in patients with obstructive jaundice: history and current status. J Gastrointest Surg. 2009;13:814-820.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 121]  [Cited by in F6Publishing: 123]  [Article Influence: 8.2]  [Reference Citation Analysis (0)]
18.  Ferrero A, Lo Tesoriere R, Viganò L, Caggiano L, Sgotto E, Capussotti L. Preoperative biliary drainage increases infectious complications after hepatectomy for proximal bile duct tumor obstruction. World J Surg. 2009;33:318-325.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 59]  [Cited by in F6Publishing: 61]  [Article Influence: 4.1]  [Reference Citation Analysis (0)]
19.  Hochwald SN, Burke EC, Jarnagin WR, Fong Y, Blumgart LH. Association of preoperative biliary stenting with increased postoperative infectious complications in proximal cholangiocarcinoma. Arch Surg. 1999;134:261-266.  [PubMed]  [DOI]  [Cited in This Article: ]
20.  El-Hanafy E. Pre-operative biliary drainage in hilar cholangiocarcinoma, benefits and risks, single center experience. Hepatogastroenterology. 2010;57:414-419.  [PubMed]  [DOI]  [Cited in This Article: ]
21.  Kawasaki S, Imamura H, Kobayashi A, Noike T, Miwa S, Miyagawa S. Results of surgical resection for patients with hilar bile duct cancer: application of extended hepatectomy after biliary drainage and hemihepatic portal vein embolization. Ann Surg. 2003;238:84-92.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 154]  [Cited by in F6Publishing: 221]  [Article Influence: 10.5]  [Reference Citation Analysis (0)]
22.  Nimura Y, Kamiya J, Kondo S, Nagino M, Uesaka K, Oda K, Sano T, Yamamoto H, Hayakawa N. Aggressive preoperative management and extended surgery for hilar cholangiocarcinoma: Nagoya experience. J Hepatobiliary Pancreat Surg. 2000;7:155-162.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in F6Publishing: 3]  [Reference Citation Analysis (0)]
23.  Maguchi H, Takahashi K, Katanuma A, Osanai M, Nakahara K, Matuzaki S, Urata T, Iwano H. Preoperative biliary drainage for hilar cholangiocarcinoma. J Hepatobiliary Pancreat Surg. 2007;14:441-446.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 64]  [Cited by in F6Publishing: 72]  [Article Influence: 4.2]  [Reference Citation Analysis (0)]
24.  Konstadoulakis MM, Roayaie S, Gomatos IP, Labow D, Fiel MI, Miller CM, Schwartz ME. Aggressive surgical resection for hilar cholangiocarcinoma: is it justified? Audit of a single center’s experience. Am J Surg. 2008;196:160-169.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 59]  [Cited by in F6Publishing: 57]  [Article Influence: 3.6]  [Reference Citation Analysis (0)]
25.  Nimura Y. Preoperative biliary drainage before resection for cholangiocarcinoma (Pro). HPB (Oxford). 2008;10:130-133.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 87]  [Cited by in F6Publishing: 76]  [Article Influence: 4.8]  [Reference Citation Analysis (0)]
26.  Sano T, Shimada K, Sakamoto Y, Yamamoto J, Yamasaki S, Kosuge T. One hundred two consecutive hepatobiliary resections for perihilar cholangiocarcinoma with zero mortality. Ann Surg. 2006;244:240-247.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 172]  [Cited by in F6Publishing: 187]  [Article Influence: 10.4]  [Reference Citation Analysis (0)]
27.  Bismuth H, Corlette MB. Intrahepatic cholangioenteric anastomosis in carcinoma of the hilus of the liver. Surg Gynecol Obstet. 1975;140:170-178.  [PubMed]  [DOI]  [Cited in This Article: ]
28.  Rahbari NN, Garden OJ, Padbury R, Brooke-Smith M, Crawford M, Adam R, Koch M, Makuuchi M, Dematteo RP, Christophi C. Posthepatectomy liver failure: a definition and grading by the International Study Group of Liver Surgery (ISGLS). Surgery. 2011;149:713-724.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 1224]  [Cited by in F6Publishing: 1478]  [Article Influence: 113.7]  [Reference Citation Analysis (0)]
29.  Capussotti L, Ferrero A, Viganò L, Sgotto E, Muratore A, Polastri R. Bile leakage and liver resection: Where is the risk? Arch Surg. 2006;141:690-694; discussion 695.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 161]  [Cited by in F6Publishing: 156]  [Article Influence: 8.7]  [Reference Citation Analysis (0)]
30.  Dindo D, Demartines N, Clavien PA. Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg. 2004;240:205-213.  [PubMed]  [DOI]  [Cited in This Article: ]
31.  Figueras J, Llado L, Valls C, Serrano T, Ramos E, Fabregat J, Rafecas A, Torras J, Jaurrieta E. Changing strategies in diagnosis and management of hilar cholangiocarcinoma. Liver Transpl. 2000;6:786-794.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 69]  [Cited by in F6Publishing: 87]  [Article Influence: 3.6]  [Reference Citation Analysis (0)]
32.  Li SQ, Chen D, Liang LJ, Peng BG, Yin XY. [The impact of preoperative biliary drainage on surgical morbidity in hilar cholangiocarcinoma patients]. Zhonghua Wai Ke Zazhi. 2009;47:1134-1137.  [PubMed]  [DOI]  [Cited in This Article: ]
33.  Dinant S, Gerhards MF, Rauws EA, Busch OR, Gouma DJ, van Gulik TM. Improved outcome of resection of hilar cholangiocarcinoma (Klatskin tumor). Ann Surg Oncol. 2006;13:872-880.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 139]  [Cited by in F6Publishing: 137]  [Article Influence: 7.6]  [Reference Citation Analysis (0)]
34.  Ercolani G, Zanello M, Grazi GL, Cescon M, Ravaioli M, Del Gaudio M, Vetrone G, Cucchetti A, Brandi G, Ramacciato G. Changes in the surgical approach to hilar cholangiocarcinoma during an 18-year period in a Western single center. J Hepatobiliary Pancreat Sci. 2010;17:329-337.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 41]  [Cited by in F6Publishing: 43]  [Article Influence: 3.1]  [Reference Citation Analysis (0)]
35.  Yu FX, Ji SQ, Su LF, Zhang SC, Zhang QY. Effectiveness and Safety of Preoperative Percutaneous Transhepatic Cholangiodrainage With Bile Re-infusion in Patients With Hilar Cholangiocarcinoma: A Retrospective Controlled Study. Am J Med Sci. 2013;346:353-357.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 7]  [Cited by in F6Publishing: 8]  [Article Influence: 0.8]  [Reference Citation Analysis (0)]
36.  Parks RW, Currie EJ, Madhavan KK, Garden OJ. Increased Bacterobilia Associated with Preoperative Biliary Drainage in Patients with Hilar Cholangiocarcinoma. HPB (Oxford). 2000;2:375-381.  [PubMed]  [DOI]  [Cited in This Article: ]
37.  Takada T, Yasuda H. Value of preoperative biliary drainage prior to bile duct cancer surgery: results of a retrospective review. Asian J Surg. 1996;19:84-87.  [PubMed]  [DOI]  [Cited in This Article: ]
38.  Nimura Y. Hepatectomy for proximal bile duct cancer. Surgical Disease of the Biliary Tract and Pancreas Multidisciplinary Management. New York: Mosby-Year Book 1994; .  [PubMed]  [DOI]  [Cited in This Article: ]
39.  Miyazaki M, Ito H, Nakagawa K, Ambiru S, Shimizu H, Shimizu Y, Okuno A, Nozawa S, Nukui Y, Yoshitomi H. Segments I and IV resection as a new approach for hepatic hilar cholangiocarcinoma. Am J Surg. 1998;175:229-231.  [PubMed]  [DOI]  [Cited in This Article: ]
40.  Neuhaus P, Jonas S, Settmacher U, Thelen A, Benckert C, Lopez-Hänninen E, Hintze RE. Surgical management of proximal bile duct cancer: extended right lobe resection increases resectability and radicality. Langenbecks Arch Surg. 2003;388:194-200.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 127]  [Cited by in F6Publishing: 110]  [Article Influence: 5.2]  [Reference Citation Analysis (0)]
41.  Kennedy TJ, Yopp A, Qin Y, Zhao B, Guo P, Liu F, Schwartz LH, Allen P, D’Angelica M, Fong Y. Role of preoperative biliary drainage of liver remnant prior to extended liver resection for hilar cholangiocarcinoma. HPB (Oxford). 2009;11:445-451.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 112]  [Cited by in F6Publishing: 106]  [Article Influence: 7.1]  [Reference Citation Analysis (0)]
42.  Kawakami H, Kuwatani M, Onodera M, Haba S, Eto K, Ehira N, Yamato H, Kudo T, Tanaka E, Hirano S. Endoscopic nasobiliary drainage is the most suitable preoperative biliary drainage method in the management of patients with hilar cholangiocarcinoma. J Gastroenterol. 2011;46:242-248.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 153]  [Cited by in F6Publishing: 152]  [Article Influence: 11.7]  [Reference Citation Analysis (0)]
43.  Kawakami H, Kondo S, Kuwatani M, Yamato H, Ehira N, Kudo T, Eto K, Haba S, Matsumoto J, Kato K. Preoperative biliary drainage for hilar cholangiocarcinoma: which stent should be selected? J Hepatobiliary Pancreat Sci. 2011;18:630-635.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 40]  [Cited by in F6Publishing: 42]  [Article Influence: 3.2]  [Reference Citation Analysis (0)]
44.  Ogura Y, Mizumoto R, Tabata M, Matsuda S, Kusuda T. Surgical treatment of carcinoma of the hepatic duct confluence: analysis of 55 resected carcinomas. World J Surg. 1993;17:85-92; discussion 92-93.  [PubMed]  [DOI]  [Cited in This Article: ]