In recent years, covered self-expandable metal stent (CSEMS) deployment is widely used for the management of unresectable malignant lower biliary strictures [
Recently, there have been a few reports describing EST before CSEMS deployment for pancreatitis prevention as being unnecessary when the pancreatic duct is obstructed [
In the present study, we retrospectively assessed the need for EST before deployment of CSEMS including fully covered type stents for malignant lower biliary stricture with pancreatic duct obstruction.
We retrospectively analyzed the medical records of 2078 patients, who underwent endoscopic retrograde cholangiopancreatography (ERCP) at St. Marianna University School of Medicine Hospital between January 2007 and December 2012. Among them, this study included 79 consecutive patients (40 male and 39 female) who underwent CSEMS deployment for unresectable malignant lower biliary stricture with pancreatic duct obstruction due to tumor invasion. Pancreatic duct obstruction was radiologically defined by abdominal computed tomography (CT), magnetic resonance cholangiopancreatography (MRCP), and/or ERCP when the main pancreatic duct was obstructed by the tumor and also the distal main pancreatic duct was dilated to 4 mm or more. We chose 4 mm as the cutoff since that is at least twice the size of normal pancreatic duct. Lower biliary stricture was defined as those of more than 2 cm downstream from bifurcation of the common bile duct. We excluded patients who underwent CSEMS deployment above the papilla. We also excluded patients with postoperative anatomy such as Billroth II or Roux-en-Y. The etiology of lower biliary stricture was pancreatic cancer in 73 patients, ampullary carcinoma in 4, gallbladder cancer with direct infiltration of pancreas in 1, and pancreatic metastasis from malignant schwannoma in 1. The diagnosis of unresectable malignant biliary obstruction was based on imaging and/or pathological findings before CSEMS deployment. The mean age of the patients was 72.7 years (range: 44–87 years).
The EST group included 38 patients who underwent EST before CSEMS deployment, and the non-EST group included 41 who did not undergo EST. EST was performed using the electrosurgical generator with 120 Watt Endocut mode, and the incision range was small (incision reaching the hooding fold) or medium (incision up to a portion of the hooding fold) in all patients. Although it was difficult to solve the details for performing EST because of the property of retrospective study, many of the reasons for having performed EST were to prevent pancreatitis or to allow easier passage of accessories. Ultimately, the decision of with or without EST was left to the operator’s discretion. All ERCPs were performed by several experienced endoscopists.
While all CSEMSs were 10 mm in diameter, fully covered type stents were deployed in 22 patients and partially covered type stents in 57. The fully covered type stents used were WallFlex Biliary RX stents (Microvasive, Boston Scientific Corp.) in 11 patients, Niti-S ComVi stents (Taewoong Medical Inc., Seoul, Korea) in 7, Hanaro stents (MItech, Seoul, Korea) in 3, and Zeostent (Zeon Medical Inc., Tokyo, Japan) in 1. The partially covered type stents used were WallFlex Biliary RX stents (Microvasive, Boston Scientific Corp.) in 33 patients, Niti-S ComVi stents (Taewoong Medical Inc., Seoul, Korea) in 22, and WALLSTENT (Microvasive, Boston Scientific Corp., Natick, MA) in 2. All stents whether fully covered type or partially covered type were positioned across the bile duct orifice with about 5 mm of the distal end of the stent protruding into the duodenum on the stent full expansion.
Age, sex, primary diseases, stent types, procedure time, duration of follow-up, technical success rates, dilation rates of stents at the papilla, serum amylase levels, incidence of pancreatitis, and the incidence of complications were retrospectively compared between the EST (
Technical success was defined as a serum total bilirubin level decrease to at most 3 mg/dL or at most 50% of the previous level within 2 weeks after CSEMS deployment. Based on radiography performed at least 5 days after CSEMS deployment, insufficient dilation was defined as the presence of notch constriction at the site of stent across the papilla, and favorable dilation was defined as the absence of such constriction. Serum amylase levels (normal range: 37–124 IU/L) were measured before 3 hours, 1 day, and 2 days after CSEMS deployment. Diagnoses and severities of complications, such as pancreatitis, bleeding, perforation, and cholangitis, were determined according to the consensus criteria proposed by Cotton et al. [
Statistical analysis was carried out using the Prism 5 program (GraphPad Software, Inc., CA, USA) and SPSS (version 19; SPSS, Chicago, IL, USA). The
There were no differences in age, sex, primary disease, stent types, or duration of the follow-up period between the EST and the non-EST groups. Total procedure times were longer for patients in EST group (34 ± 16 min) as compared with those in the non-EST group (27 ± 12 min) (
Patient characteristics.
EST group ( |
Non-EST group ( |
| |
---|---|---|---|
Age (mean ± SD) | 72 ± 11 | 73 ± 9 | 0.589 |
Sex (male/female) | 21/17 | 19/22 | 0.428 |
Pancreatic cancer | 37 | 36 | 0.239 |
Ampullary carcinoma | 0 | 4 | 0.144 |
Gallbladder cancer | 1 | 0 | 0.969 |
Metastatic pancreatic cancer | 0 | 1 | 0.969 |
Incision range of EST | |||
Small | 20 | ||
Medium | 18 | ||
Large | 0 | ||
Covered self-expandable metal stent | |||
Fully covered type | 9 | 13 | 0.427 |
Partially covered type | 29 | 28 | |
Stent length |
6.0 ± 1.0 | 5.8 ± 1.0 | 0.380 |
Procedure time |
34 ± 16 | 27 ± 12 | 0.032 |
Follow-up period |
216 ± 224 | 157 ± 183 | 0.202 |
EST: endoscopic sphincterotomy.
The technical success rates were 100% in both the EST and the non-EST groups. Favorable drainage was thus achieved regardless of whether EST was performed.
The rates of stent dilation at the papilla were 100% in both the EST and the non-EST groups. Even without EST, no notch constriction persisted at the stenting site across the papilla in any patient.
As for the mean serum amylase levels, there were no apparent differences between the EST and the non-EST groups (Table
Comparison of complications between the EST and non-EST groups.
EST group ( |
Non-EST group ( |
| |
---|---|---|---|
Serum amylase level (IU/L, mean ± SD) | |||
Before CSEMS placement | 130 ± 196 | 106 ± 100 | 0.563 |
3 hours after CSEMS placement | 171 ± 232 | 136 ± 108 | 0.638 |
1 day after CSEMS placement | 149 ± 182 | 174 ± 185 | 0.324 |
2 days after CSEMS placement | 118 ± 142 | 154 ± 153 | 0.144 |
Complications (%) | 7 (18.4) | 6 (14.6) | 0.650 |
Pancreatitis | 1 (2.6) | 1 (2.4) | 0.508 |
Cholecystitis | 2 (5.3) | 2 (4.9) | 0.969 |
Cholangitis | 1 (2.6) | 0 (0) | 0.969 |
Bleeding | 1 (2.6) | 0 (0) | 0.969 |
Liver abscess | 1 (2.6) | 0 (0) | 0.969 |
Migration | 1 (2.6) | 3 (7.3) | 0.663 |
EST: endoscopic sphincterotomy. CSEMS: covered self-expandable metal stent.
The incidence of pancreatitis was 2.6% (1/38) in the EST group and 2.4% (1/41) in the non-EST group (
The overall incidence of complications including pancreatitis was 18.4% (7/38) in the EST group and 14.6% (6/41) in the non-EST group (
For the mean serum amylase levels, there were no apparent differences between the FC and PC groups. Pancreatitis occurred in only 1 PC group patient. The incidence of pancreatitis was 0% (0/13) in the FC group and 3.6% (1/28) in the PC group (
Comparison of complications between the FC and PC groups within the non-EST group.
FC group ( |
PC group ( |
| |
---|---|---|---|
Serum amylase level (IU/L, mean ± SD) | |||
Before CSEMS placement | 100 ± 101 | 108 ± 101 | 0.441 |
3 hours after CSEMS placement | 141 ± 102 | 133 ± 112 | 0.695 |
1 day after CSEMS placement | 201 ± 201 | 162 ± 180 | 0.547 |
2 days after CSEMS placement | 135 ± 126 | 163 ± 165 | 0.933 |
Complications (%) | 3 (23.1) | 3 (10.7) | 0.570 |
Pancreatitis | 0 (0) | 1 (3.6) | 0.691 |
Cholecystitis | 2 (15.4) | 0 (0) | 0.177 |
Cholangitis | 0 (0) | 0 (0) | |
Bleeding | 0 (0) | 0 (0) | |
Liver abscess | 0 (0) | 0 (0) | |
Migration | 1 (7.7) | 2 (7.1) | 0.561 |
FC: fully covered type. PC: partially covered type. EST: endoscopic sphincterotomy.
CSEMS: covered self-expandable metal stent.
The overall incidence of complications including pancreatitis was 23.1% (3/13) in the FC group and 10.7% (3/28) in the PC group (
Risk factors for overall complications after CSEMS deployment (univariate analysis).
Complication (+) |
Complication ( |
|
OR (95% CI) | |
---|---|---|---|---|
Female gender | 7 | 32 | 0.770 | 1.2 (0.38–4.1) |
Age (<60 years) | 4 | 4 | 0.022 | 6.9 (1.5–33) |
Nonpancreatic cancer | 4 | 2 | 0.006 | 14 (2.3–89) |
Periampullary diverticulum | 3 | 8 | 0.377 | 2.2 (0.49–9.6) |
Non-EST | 6 | 35 | 0.765 | 0.76 (0.23–2.5) |
Fully covered type stent | 5 | 17 | 0.499 | 1.8 (0.52–6.3) |
Pancreatic duct injection | 3 | 17 | 1.000 | 0.87 (0.21–3.5) |
Biopsy of the bile duct | 0 | 4 | 1.000 | — |
Cytology of bile juice | 1 | 5 | 1.000 | 1.0 (0.11–9.5) |
Intraductal ultrasonography | 1 | 2 | 0.421 | 2.7 (0.22–32) |
Procedure time (>45 minutes) | 2 | 8 | 0.666 | 1.3 (0.2–7.1) |
CSEMS: covered self-expandable metal stent. EST: endoscopic sphincterotomy.
Since there were only 2 patients with post-ERCP pancreatitis, it was a too small number of patients to analyze the risk factor of pancreatitis statistically by uni- and multivariate analysis. As for the risk factor of overall complications, age (<60 years) (
Risk factors for overall complications after CSEMS deployment (multivariate analysis).
|
OR (95% CI) | |
---|---|---|
Age (<60 years) | 0.003 | 12 (2.2–63) |
Nonpancreatic cancer | 0.001 | 24 (3.5–165) |
CSEMS: covered self-expandable metal stent.
CSEMS deployment has been associated with relatively high incidence of pancreatitis with reported incidences ranging from 0 to 7.3% [
There have been a few reports describing EST as not being needed before CSEMS deployment for the prevention of pancreatitis in cases with an occluded pancreatic duct [
Kawakubo et al. [
Moreover, in our results, nonpancreatic cancer was a risk factor for the development of complications after CSEMS deployment by the multivariate analysis. It is thought to be causally related to high incidence of distal migration in patients with ampullary carcinoma. In the patient of ampullary carcinoma, noncovered metallic stent or plastic tube stent may be better than CSEMS.
Finally, our study has some limitations. This was not a prospective study, so selection biases were present with regard to the type of CSEMS used and the EST procedure. The procedure was performed at the discretion of the endoscopists. Because of the retrospective design of our single center study and the limited number of patients, further prospective studies with a large number of patients should be done to confirm our results.
EST did not reduce the incidence of pancreatitis and level of amylase in the distal malignant obstruction case with main pancreatic duct obstruction, and EST was not identified as a risk factor of all complications after CSEMS deployment. A potential advantage of the non-EST approach could be a shorter procedure.