Risk factors for pancreatitis following transpapillary self-expandable metal stent placement

Endoscopic Sphincterotomy before Fully Covered Metal Stent Placement Is Not Required for Distal Malignant Biliary Stricture due to a Pancreatic Head Tumor

Background/Aims

Endoscopic sphincterotomy (EST) is often performed before fully covered self-expandable metal stent (FCSEMS) placement in order to prevent pancreatitis. However, it is not clear whether EST prevents pancreatitis or affects other adverse events (AEs). This study is conducted to evaluate the necessity of EST before FCSEMS placement for distal malignant biliary strictures due to a pancreatic head tumor.

Methods

This study included 68 patients who underwent FCSEMS placement for distal malignant biliary stricture due to a pancreatic head tumor. Treatment outcomes and AEs were retrospectively compared between 32 patients with EST before FCSEMS placement (EST group) and 36 patients without EST (non-EST group).

Results

The success rates of drainage for the EST and non-EST groups were 100% and 97.2%, respectively (P = 0.95). The incidence of pancreatitis in the EST and non-EST groups was 3.1% and 0%, respectively (P = 0.95). The incidence of hyperamylasemia in the EST and non-EST groups was 12.5% and 13.9%, respectively (P = 0.85). The incidence of all AEs in the EST and non-EST groups was 15.6% (pancreatitis: 1, cholecystitis: 2, and stent migration: 2) and 13.9% (cholecystitis: 3, stent migration: 2), respectively (P = 0.89).

Conclusions

EST before FCSEMS placement for distal malignant biliary stricture due to a pancreatic head tumor does not affect the successful drainage and incidence of adverse events. The necessity of EST to prevent pancreatitis before FCSEMS placement was deemed low.

Endoscopic biliary self-expandable metallic stent in malignant biliary obstruction with or without sphincterotomy: systematic review and meta-analysis

Background and aim  To assess the rate of adverse events and the technical success rate of biliary stenting with or without EBS.  Methods  A literature search up to February 2017 was performed. Studies assessing adverse events (AEs) and technical success rates of stenting with or without EBS were considered. Results  Seven studies (870 patients; 12 treatment arms) were included. Early AEs, i. e. those occurring within 30 days, were significantly lower in no-EBS vs. EBS-group (11 % vs . 20.1 %; OR: 0.36, 95 %CI: 0.13 - 1.00). Rates of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis were not significantly different in the two groups (no-EBS vs . EBS: 6.1 % vs 5 %; OR: 1.33, 95 %CI: 0.68 - 2.59). The rate of bleeding was significantly lower in patients without EBS (no-EBS vs EBS: 0 % vs 5 %; OR: 0.12, 95 % CI: 0.03 - 0.45). Rates of cholangitis were significantly lower in patients without EBS (no-EBS vs . EBS: 3.3 % vs. 7.4 %; OR: 0.38, 95 %CI: 0.17 - 0.83). Both late AEs and mortality rates did not significantly differ between no-EBS and EBS patients (19.9 % vs. 18.9 %; OR: 0.93, 95 %CI: 0.56 - 1.53, and 2.5 % vs. 2.9 %; OR: 1.18, 95 %CI: 0.22 - 6.29, respectively). The technical success rate for stent insertion also did not differ (98 % vs. 97.6 %; OR: 1.05, 95 %CI: 0.42 - 2.63). Conclusion  EBS seems to be associated, in the first 30 days after the procedure, with an increased risk of cholangitis and bleeding. No difference was observed in the rate of post-ERCP pancreatitis.

Prospective multicenter study of primary EUS-guided choledochoduodenostomy using a covered metal stent

Background and Objectives:

EUS-guided biliary drainage (EUS-BD) is increasingly reported as a salvage technique after failed endoscopic retrograde cholangiopancreatography, but it is still controversial whether EUS-BD can replace transpapillary biliary stenting. Therefore, we conducted this multicenter, prospective study of EUS-guided choledochoduodenostomy (EUS-CDS) using a covered metallic stent (CMS) as primary biliary drainage for unresectable distal malignant biliary obstruction (MBO).

Methods:

Patients with unresectable distal MBO without any prior drainage are enrolled. Primary endpoint is a technical success and secondary endpoints are adverse events, functional success, and recurrent biliary obstruction (RBO) of EUS-CDS. Clinical outcomes were compared between EUS-CDS and transpapillary stenting as a control.

Results:

A total of 34 patients were enrolled in 10 Japanese institutions. The cause of MBO was pancreatic cancer in 28 patients. Median tumor size and common bile duct diameter were 31 and 13 mm, respectively. Technical success rate was 97% with a median procedure time of 25 min and functional success rate was 100%. The rate of RBO was 29% and the causes of RBO were nontumor related: Migration in 18%, sludge/food impaction in 9%, and stent impaction to the duodenal wall in 3%. Other adverse events were abdominal pain in 6% and cholecystitis in 9%. A median cumulative time to RBO was 11.3 months. The rate of RBO and cumulative time to RBO of EUS-CDS were comparable to those of transpapillary stenting (36% and 9.1 months, respectively).

Conclusion:

EUS-CDS using a CMS as primary biliary drainage was technically feasible and its safety appeared comparable to transpapillary stenting.

Risk Factors for Post-Endoscopic Retrograde Cholangiopancreatography Pancreatitis: Evidence from 1786 Cases

BACKGROUND Postoperative pancreatitis is one of the most serious complications in endoscopic retrograde cholangiopancreatography (ERCP). To detect potential risk factors for post-ERCP hyperamylasemia and pancreatitis. MATERIAL AND METHODS We reviewed 1786 ERCP procedures in Zhongnan Hospital of Wuhan University from January 2015 to April 2018. Clinical data were extracted, and the complications after ERCP procedures were re-evaluated. Single- and multiple-variable analyses were conducted to detect the potential risk factors. RESULTS We found that 1786 procedures were applied on 1707 patients; 64 patients (3.58%) developed pancreatitis, while asymptomatic hyperamylasemia occurred in 263 cases (14.73%). In multivariate analysis, pancreatic deep wire pass (odds ratio [OR]: 2.280, 95% CI [confidence interval]: 1.129-4.605, P=0.022), endoscopic metal biliary endoprosthesis (OR: 2.399, 95% CI: 1.120-5.138, P=0.024), operation after liver transplantation (OR: 3.057, 95% CI: 1.110-8.422, P=0.031), and fistulotomy (OR: 3.148, 95% CI: 1.036-9.561, P=0.043) were identified as independent risk factors for post-ERCP pancreatitis. Pancreatic deep wire pass (OR: 1.678, 95% CI: 1.136-2.478, P=0.009), fistulotomy (OR: 2.553, 95% CI: 1.096-5.948, P=0.030), and younger age (OR: 0.990, 95% CI: 0.980-0.999, P=0.037) were identified as independent risk factors for hyperamylasemia. CONCLUSIONS To prevent post-ERCP pancreatitis, it is important to avoid high-risk procedures such as fistulotomy and pancreatic deep wire pass, especially in high-risk patients with liver transplantation. For patients with endoscopic metal biliary endoprosthesis, clinicians should pay more attention to the occurrence of post-ERCP pancreatitis.

Evaluation of a 12-mm diameter covered self-expandable end bare metal stent for malignant biliary obstruction

Background and study aims  Biliary metallic stents are used to drain unresectable malignant distal biliary obstructions. This study aimed to evaluate the efficacy of a novel 12-mm-diameter covered, self-expandable end bare metal stent (12-mm CSEEMS). Patients and methods  We evaluated 99 patients with unresectable malignant distal biliary obstructions treated with covered biliary metallic stents. Of the 99 patients, 33 underwent 12-mm CSEEMS placement between June 2015 and April 2017 (12-mm-CSEEMS group) and 66 underwent 10-mm fully-covered self-expandable metal stent (FCSEMS) placement between January 2010 and July 2015 (10-mm-FCSEMS group). The overall survival (OS), the recurrent biliary obstruction (RBO), cause of RBO, time to RBO (TRBO) and adverse events in 12-mm-CSEEMS group and 10-mm-FCSEMS group were evaluated retrospectively. Results  The OS tended to be longer in the 12-mm-CSEEMS group (log rank, P  = 0.081) and TRBO was significantly longer in the 12-mm-CSEEMS group (log rank, P  = 0.001) than in the 10-mm-FCSEMS group. Both univariate (HR, 0.449; 95 % CI, 0.27967 - 0.72215; P  = 0.001) and multivariate (HR, 0.458; 95 % CI, 0.28395 - 0.73744; P  = 0.001) Cox hazard analysis found that risk of RBO was significantly lower in 12-mm CSEEMS than in 10-mm FCSEMS. There were no significant differences between the 12-mm-CSEEMS group and 10-mm-FCSEMS group regarding the cause of RBO and adverse events. Conclusions  The 12-mm CSEEMS showed a low risk of RBO compared with 10-mm FCSEMS and was considered to be effective and safe for draining unresectable malignant distal biliary obstruction.

A Prospective Multicenter Study of a Fully Covered Metal Stent in Patients with Distal Malignant Biliary Obstruction: WATCH-2 Study

BACKGROUND

Both fully covered (FC) and partially covered (PC) self-expandable metal stents (SEMSs) are now commercially available for distal malignant biliary obstruction (MBO). While FCSEMS can be easily removed at the time of re-interventions, it is theoretically prone to migration. However, few comparative data between FC and PC SEMSs have been reported.

AIMS

The aim of this study was to compare clinical outcomes of FCSEMS with those of PCSEMS.

METHODS

This was a multicenter, prospective study of FCSEMS for unresectable distal MBO with a historical control of PCSEMS, which was previously reported as the WATCH study. The primary outcome was recurrent biliary obstruction (RBO), and secondary outcomes were stent migration, stent removal, stent-related adverse events, and survival.

RESULTS

A total of 151 cases with unresectable distal MBO undergoing FCSEMS placement were enrolled and compared with a historical cohort of 141 cases undergoing PCSEMS placement. No significant differences were found in the rate of RBO (29 vs. 33%; P = 0.451), time to RBO (318 vs. 373 days; P = 0.382), and survival (229 vs. 196 days; P = 0.177) between FCSEMS and PCSEMS. The rate of stent migration also did not differ significantly between the two groups (14 vs. 8%; P = 0.113). The removal of FCSEMSs was successful in all 24 attempted cases (100%).

CONCLUSIONS

FCSEMSs appeared comparable to PCSEMSs in terms of RBO without a significant increase in stent migration rate in patients with unresectable distal MBO.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000007131.

EUS-Guided Biliary Drainage Versus ERCP for the Primary Palliation of Malignant Biliary Obstruction: A Multicenter Randomized Clinical Trial

OBJECTIVES

The goal of the study was to determine whether endoscopic ultrasound (EUS)-guided biliary drainage (EUS-BD) is comparable to conventional transpapillary stenting with endoscopic retrograde cholangiopancreatography (ERCP) in palliation of malignant distal biliary obstruction. Although ERCP for the palliation of malignant biliary obstruction is the standard of care, post-procedure pancreatitis and stent dysfunctions are not uncommon. While EUS-BD has garnered interest as a viable alternative when ERCP is impossible, its role as a primary palliation of malignant distal biliary obstruction is yet to be proven.

METHODS

We performed random allocation to EUS-BD or ERCP in 125 patients with unresectable malignant distal biliary obstruction at four tertiary academic referral centers in South Korea.

RESULTS

Technical success rates were 93.8% (60/64) for EUS-BD and 90.2% (55/61) for ERCP (difference 3.6%, 95% 1-sided confidence interval lower limit -4.4%, P = 0.003 for noninferiority margin of 10%). Clinical success rates were 90.0% (54/60) in EUS-BD and 94.5% (52/55) in ERCP (P = 0.49). Lower rates of overall adverse events (6.3% vs 19.7%, P = 0.03) including post-procedure pancreatitis (0 vs 14.8%), reintervention (15.6% vs 42.6%), and higher rate of stent patency (85.1% vs 48.9%) were observed with EUS-BD. EUS-BD was also associated with more preserved quality of life (QOL) than transpapillary stenting after 12 weeks of the procedure.

CONCLUSIONS

This study demonstrated comparable technical and clinical success rates between EUS-BD and ERCP in relief malignant distal biliary obstruction. Substantially longer duration of patency coupled with lower rates of adverse events and reintervention, and more preserved QOL were observed with EUS-BD (cris.nih.go.kr, Identifier: KCT0001396, https://cris.nih.go.kr/cris/search/search_result_st01_en.jsp?seq=9716&ltype=&rtype= ).

New 14-mm diameter Niti-S biliary uncovered metal stent for unresectable distal biliary malignant obstruction

AIM

To investigate whether an uncovered self-expandable metal stent (UCSEMS) with a large diameter could prevent recurrent biliary obstruction (RBO).

METHODS

Thirty-eight patients with malignant biliary obstruction underwent treatment with an UCSEMS with a 14-mm diameter (Niti-S 14). Retrospectively, we evaluated technical and functional success rate, RBO rate, time to RBO, survival time, and adverse events in these patients.

RESULTS

Stent placement success and functional success were achieved in all patients. Two patients (5.3%) had RBO due to tumor ingrowth or overgrowth. The median time to RBO was 190 (range, 164-215) d. The median survival time was 120 (range, 18-502) d. The 6-mo non-RBO rate was 91%. Other adverse events other than RBO occurred as follows: Acute cholecystitis, post-ERCP pancreatitis, hemobilia, and fever without exacerbation of liver injury, and liver abscess in 4 (10.3%), 3 (7.9%), 2 (5.3%), 1 (2.6%), and 1 (2.6%), respectively. Migration of the stents was not observed.

CONCLUSION

Niti-S 14 is considered to be a preferable metal stent because of a low rate of RBO with no migration.

International study of endoscopic management of distal malignant biliary obstruction combined with duodenal obstruction

OBJECTIVE

Endoscopic transpapillary or endoscopic ultrasound (EUS)-guided stent placement is used for nonresectable distal malignant biliary obstruction. We conducted a retrospective study to evaluate endoscopic biliary drainage in patients with duodenal obstruction.

METHODS

We included consecutive patients who underwent endoscopic biliary drainage combined with a duodenal stent at 16 referral centers in four Asian countries. The primary outcome was time to recurrent biliary obstruction (TRBO). We assessed TRBO according to the sequence of biliary and duodenal obstruction (group 1/2/3, biliary obstruction first/concurrent/duodenal obstruction first, respectively) or the location of duodenal obstruction (type I/II/III, proximal to/affecting/distal to the ampulla, respectively). We also evaluated functional success and adverse events.

RESULTS

We included 110 patients (group1/2/3, 67/29/14 patients; type I/II/III, 45/46/19 patients; endoscopic retrograde cholangiopancreatography [ERCP]/EUS-guided choledocoduodenostomy/EUS-guided hepaticogastrostomy, 90/10/10 patients, respectively). The median TRBO of all cases was 450 days (interquartile range, 212-666 days) and functional success was achieved in 105 cases (95%). The TRBO did not differ significantly by the timing or location of duodenal obstruction (p = .30 and .79, respectively). The TRBO of metal stents (n = 96) tended to be longer compared with plastic stents (n = 14, p = .083). Compared with ERCP, EUS-guided biliary drainage was associated with a higher rate of adverse events.

CONCLUSION

Transpapillary or transmural endoscopic biliary drainage with a duodenal stent was effective, irrespective of the timing or location of duodenal obstruction. A prospective study is required considering the tradeoff of technical success rate, stent patency, and adverse events (ClinicalTrials.gov number, NCT02376907).

Antireflux Metal Stent as a First-Line Metal Stent for Distal Malignant Biliary Obstruction: A Pilot Study

Background/Aims

In distal malignant biliary obstruction, an antireflux metal stent (ARMS) with a funnel-shaped valve is effective as a reintervention for metal stent occlusion caused by reflux. This study sought to evaluate the feasibility of this ARMS as a first-line metal stent.

Methods

Patients with nonresectable distal malignant biliary obstruction were identified between April and December 2014 at three Japanese tertiary centers. We retrospectively evaluated recurrent biliary obstruction and adverse events after ARMS placement.

Results

In total, 20 consecutive patients were included. The most common cause of biliary obstruction was pancreatic cancer (75%). Overall, recurrent biliary obstruction was observed in seven patients (35%), with a median time to recurrent biliary obstruction of 246 days (range, 11 to 246 days). Stent occlusion occurred in five patients (25%), the causes of which were sludge and food impaction in three and two patients, respectively. Stent migration occurred in two patients (10%). The rate of adverse events associated with ARMS was 25%: pancreatitis occurred in three patients, cholecystitis in one and liver abscess in one. No patients experienced non-occlusion cholangitis.

Conclusions

The ARMS as a first-line biliary drainage procedure was feasible. Because the ARMS did not fully prevent stent dysfunction due to reflux, further investigation is warranted.

Understanding the Mechanical forces of Self-Expandable Metal Stents in the Biliary Ducts

Self-expandable metallic stent (SEMS) was an effective biliary endoprosthesis. Mechanical properties of SEMS, radial and axial force (RF, AF), may play important roles in the bile duct after placement. RF was well known dilation force and influenced on the occurrence of migration. AF, newly proposed by this author, was defined as the recovery force when the SEMS vended. AF was related with the cause of bile duct kinking, pancreatitis, and cholecystitis due to the compression of the bile duct, orifice of the cystic duct, and pancreatic orifice. Ideal SEMS may show high RF and low AF.

Endoscopic management of combined malignant biliary and gastric outlet obstruction

Patients with periampullary cancer or gastric cancer often develop malignant biliary obstruction (MBO) and gastric outlet obstruction (GOO), and combined MBO and GOO is not rare in these patients. Combined MBO and GOO is classified by its location and sequence, and treatment strategy can be affected by this classification. Historically, palliative surgery, hepaticojejunostomy and gastrojejunostomy were carried out, but the current standard treatment is combined transpapillary stent and duodenal stent placement. Although a high technical success rate is reported, the procedure can be technically difficult and duodenobiliary reflux with subsequent cholangitis is common after double stenting. Recent development of endoscopic ultrasound (EUS)-guided procedures enables the management of MBO as well as GOO under EUS guidance. EUS-guided biliary drainage is now increasingly reported as an alternative to percutaneous transhepatic biliary drainage in failed endoscopic retrograde cholangiopancreatography (ERCP), and GOO is one of the major reasons for failed ERCP. In addition to EUS-guided biliary drainage, the feasibility of EUS-guided double-balloon-occluded gastrojejunostomy bypass for MBO was recently reported, and EUS-guided double stenting can potentially become the treatment of choice in the future. However, as each procedure has its advantages and disadvantages, treatment strategy should be selected based on the type of obstruction and the prognosis and performance status of the patient.

Metal or plastic stents for preoperative biliary drainage in resectable pancreatic cancer

INTRODUCTION

In pancreatic cancer, preoperative biliary drainage (PBD) increases complications compared with surgery without PBD, demonstrated by a recent randomised controlled trial (RCT). This outcome might be related to the plastic endoprosthesis used. Metal stents may reduce the PBD-related complications risk.

METHODS

A prospective multicentre cohort study was performed including patients with obstructive jaundice due to pancreatic cancer, scheduled to undergo PBD before surgery. This cohort was added to the earlier RCT (ISRCTN31939699). The RCT protocol was adhered to, except PBD was performed with a fully covered self-expandable metal stent (FCSEMS). This FCSEMS cohort was compared with the RCT's plastic stent cohort. PBD-related complications were the primary outcome. Three-group comparison of overall complications including early surgery patients was performed.

RESULTS

53 patients underwent PBD with FCSEMS compared with 102 patients treated with plastic stents. Patients' characteristics did not differ. PBD-related complication rates were 24% in the FCSEMS group vs 46% in the plastic stent group (relative risk of plastic stent use 1.9, 95% CI 1.1 to 3.2, p=0.011). Stent-related complications (occlusion and exchange) were 6% vs 31%. Surgical complications did not differ, 40% vs 47%. Overall complication rates for the FCSEMS, plastic stent and early surgery groups were 51% vs 74% vs 39%.

CONCLUSIONS

For PBD in pancreatic cancer, FCSEMS yield a better outcome compared with plastic stents. Although early surgery without PBD remains the treatment of choice, FCSEMS should be preferred over plastic stents whenever PBD is indicated.

TRIAL REGISTRATION NUMBER

Dutch Trial Registry (NTR3142).

Metal versus plastic stents for drainage of malignant biliary obstruction before primary surgical resection

BACKGROUND AND AIMS

Preoperative biliary drainage (PBD) with stent placement has been commonly used for patients with malignant biliary obstruction. In PBD, the placement of fully covered self-expandable metal stents (FCSEMSs) may provide better patency duration and a lower incidence of cholangitis compared with plastic stents. We aimed to evaluate which type of stent showed better outcomes in PBD.

METHODS

In this multicenter, prospective randomized trial, we compared PBD with FCSEMSs versus plastic stents in 86 patients with malignant biliary obstruction between January 2012 and December 2014. Patients with obstructive jaundice were randomly assigned to undergo PBD either with plastic stents or FCSEMS placement.

RESULTS

Baseline characteristics were not significantly different between the 2 groups. Endoscopic stent placement was technically successful in all patients. Procedure-related adverse events were not significantly different between the 2 groups (plastic vs FCSEMS group; 16.3% vs 16.3%, P = 1.0). Reintervention was required in 16.3% of the plastic stent group and 14.0% of the FCSEMS group (P = .763). The interval to surgery after PBD (plastic vs FCSEMS group; 14.2 ± 8.3 vs 12.3 ± 6.9 days, P = .426) was not significantly different between groups. Surgery-related adverse events occurred in 43.6% of the plastic stent group and 40.0% of the FCSEMS group (P = .755).

CONCLUSIONS

In patients with resectable malignant biliary obstruction, the outcomes of PBD with plastic stents and FCSEMSs were similar. Considering the cost-effectiveness, PBD with plastic stents may be preferable to FCSEMS placement. (Clinical trial registration number: NCT01789502.).

Pilot study of a novel, large-bore, fully covered self-expandable metallic stent for unresectable distal biliary malignancies

BACKGROUND AND AIM

In patients with unresectable malignant distal biliary obstruction, covered self-expandable metallic stents (CSEMS) may remain patent longer than uncovered self-expandable metallic stents as a result of tumor ingrowth prevention. One main cause of recurrent biliary obstruction (RBO) in CSEMS is sludge formation, which can be prevented using a large-bore stent. Therefore, we developed a novel, 12-mm diameter fully covered SEMS (FCSEMS) and investigated its clinical safety, efficacy, and rate of adverse events.

METHODS

This prospective, multicenter pilot study, which ran between June 2011 and November 2012, included 38 consecutive patients with unresectable malignant distal biliary obstruction. All patients underwent endoscopic insertion of our novel stent. Primary endpoint was non-RBO rate 6 months after placement.

RESULTS

Technical and functional success rates of the procedures were 100%. Six-month non-RBO rate was 50%, and median time to RBO was 184 days. Median survival time was 241 days. Twelve patients died within 6 months after stent placement without RBO. RBO was observed in 10 patients (26%), with seven experiencing stent occlusion and three experiencing stent migration. Adverse events other than RBO (at <30 days) developed in six patients (16%; cholecystitis, one; pancreatitis, one; hyperamylasemia, one; pancreatic ductitis, one; abdominal pain, two). Stent removal for reintervention was successfully completed in eight patients.

CONCLUSION

Our novel FCSEMS may be safe and effective for managing malignant distal obstruction with an acceptable incidence of adverse events.

Covered versus uncovered self-expandable metal stents for malignant biliary strictures: A meta-analysis and systematic review

Self-expandable metal stents (SEMS) are used for palliating inoperable malignant biliary strictures. It is unclear if covered metal stents are superior to uncovered metal stents in these patients. We compared clinical outcomes in patients with covered and uncovered stents. Studies using covered and uncovered metallic stents for palliation in patients with malignant biliary stricture were reviewed. Articles were searched in MEDLINE, PubMed, and Ovid journals. Fixed and random effects models were used to calculate the pooled proportions. Initial search identified 1436 reference articles, of which 132 were selected and reviewed. Thirteen studies (n = 2239) for covered and uncovered metallic stents which met the inclusion criteria were included in this analysis. Odds ratio for stent occlusion rates in covered vs. uncovered stents was 0.79 (95 % CI = 0.65 to 0.96). Survival benefit in patients with covered vs. uncovered stents showed the odds ratio to be 1.29 (95 % CI = 0.95 to 1.74). Pooled odds ratio for migration of covered vs. uncovered stents was 9.9 (95 % CI = 4.5 to 22.3). Covered stents seemed to have significantly lesser occlusion rates, increased odds of migration, and increased odds of pancreatitis compared to uncovered stents. There was no statistically significant difference in the survival benefit, overall adverse event rate, and patency period of covered vs. uncovered metal stents in patients with malignant biliary strictures.

Lower incidence of complications in endoscopic nasobiliary drainage for hilar cholangiocarcinoma

AIM: To identify the most effective endoscopic biliary drainage technique for patients with hilar cholangiocarcinoma.

METHODS: In total, 118 patients with hilar cholangiocarcinoma underwent endoscopic management [endoscopic nasobiliary drainage (ENBD) or endoscopic biliary stenting] as a temporary drainage in our institution between 2009 and 2014. We retrospectively evaluated all complications from initial endoscopic drainage to surgery or palliative treatment. The risk factors for biliary reintervention, post-endoscopic retrograde cholangiopancreatography (post-ERCP) pancreatitis, and percutaneous transhepatic biliary drainage (PTBD) were also analyzed using patient- and procedure-related characteristics. The risk factors for bilateral drainage were examined in a subgroup analysis of patients who underwent initial unilateral drainage.

RESULTS: In total, 137 complications were observed in 92 (78%) patients. Biliary reintervention was required in 83 (70%) patients. ENBD was significantly associated with a low risk of biliary reintervention [odds ratio (OR) = 0.26, 95%CI: 0.08-0.76, P = 0.012]. Post-ERCP pancreatitis was observed in 19 (16%) patients. An absence of endoscopic sphincterotomy was significantly associated with post-ERCP pancreatitis (OR = 3.46, 95%CI: 1.19-10.87, P = 0.023). PTBD was required in 16 (14%) patients, and Bismuth type III or IV cholangiocarcinoma was a significant risk factor (OR = 7.88, 95%CI: 1.33-155.0, P = 0.010). Of 102 patients with initial unilateral drainage, 49 (48%) required bilateral drainage. Endoscopic sphincterotomy (OR = 3.24, 95%CI: 1.27-8.78, P = 0.004) and Bismuth II, III, or IV cholangiocarcinoma (OR = 34.69, 95%CI: 4.88-736.7, P < 0.001) were significant risk factors for bilateral drainage.

CONCLUSION: The endoscopic management of hilar cholangiocarcinoma is challenging. ENBD should be selected as a temporary drainage method because of its low risk of complications.

Does endoscopic sphincterotomy reduce the risk of post-endoscopic retrograde cholangiopancreatography pancreatitis after biliary stenting? A systematic review and meta-analysis

BACKGROUND AND AIM

Endoscopic biliary sphincterotomy (ES) is often carried out prior to placement of a biliary stent apparently to reduce the risk of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). However, the protective effect of ES prior to biliary stenting is controversial. The objective of this meta-analysis is to compare the risk of PEP and other complications after the placement of biliary stent with or without ES in patients with biliary obstruction and bile leak.

METHODS

We carried out a systematic search in several electronic databases for randomized controlled trials (RCT) and observational studies (OS) comparing the risk of PEP after biliary stenting with or without ES. The Mantel-Haenszel method was used to pool data of adverse outcomes into fixed or random effect model meta-analyses.

RESULTS

Seventeen studies (five RCT and 12 OS) with a total of 2710 patients met the inclusion criteria. No significant difference was observed in the risk of PEP with biliary stenting with and without ES (RD -0.01; 95% confidence interval [CI] -0.03, 0.01). In a subgroup analysis of stenting for biliary obstruction, no difference in the risk of PEP was observed with or without ES. However, ES was associated with lower risk of PEP in patients undergoing biliary stenting for bile leak (RD -0.05; CI -0.10, -0.01).

CONCLUSIONS

ES shows risk reduction in prevention of PEP in patients undergoing endoscopic stenting for bile leak. However, placement of biliary stent without ES is not associated with an increased risk of PEP in patients with distal bile duct obstruction with involvement of pancreatic duct.

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 < 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 ≥ 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 < 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.

Basic Knowledge about Metal Stent Development

Biliary self-expandable metal stents (SEMS), a group of non-vascular stents, have been used in the palliative management of biliary obstruction around the world. However, there are still unmet needs in the clinical application of biliary SEMS. Comprehensive understanding of the SEMS is required to resolve the drawbacks and difficulties of metal stent development. The basic structure of SEMS, including the materials and knitting methods of metal wires, covering materials, and radiopaque markers, are discussed in this review. What we know about the physical and mechanical properties of the SEMS is very important. With an understanding of the basic knowledge of metal stents, hurdles such as stent occlusion, migration, and kinking can be overcome to develop more ideal SEMS.

A prospective, multicenter study of a double stent system for palliative treatment of malignant extrahepatic biliary obstructions

BACKGROUND

A double stent system (covered stent in uncovered stent) was designed to provide long-term patency without tumor ingrowth or stent-related complications, such as stent migration, cholecystitis, or pancreatitis.

PURPOSE

To investigate the safety and efficacy of double stents in patients with malignant extrahepatic biliary obstructions.

MATERIAL AND METHODS

This prospective, nonrandomized, multicenter study enrolled 160 consecutive patients (102 men; mean age, 64 years; range, 33-91 years) with malignant extrahepatic biliary obstructions treated with a double stent system from January 2010 to March 2012.

RESULTS

The technical success rate of the double stent placement was 100%. No stent migration was observed. Procedure-related minor (self-limiting hemobilia [n = 6] and cholangitis [n = 2]) and major (pancreatitis [n = 16], cholecystitis [n = 3], and hepatic abscess [n = 2]) complications occurred in a total of 29 patients. The mean serum bilirubin level, which was 8.9 ± 5.6 mg/dL before drainage, decreased to 2.2 ± 4.6 mg/dL 1 month after stent placement (P < 0.001). Successful internal drainage was achieved in 148 patients (92.5%). During the mean follow-up period of 205 days, acute cholecystitis (n = 3) and hepatic abscess (n = 2) occurred in five patients. The median patient survival and stent patency time were 135 days (95% confidence interval [CI], 96-160 days) and 114 days (95% CI, 83-131 days), respectively. Of 153 patients, 22 (14.4%) presented with stent dysfunction due to sludge incrustation (n = 17), tumor overgrowth (n = 4), or blood clot (n = 1), and required repeat intervention. Tumor ingrowth was not observed in any of these patients.

CONCLUSION

Percutaneous treatment of malignant extrahepatic biliary obstruction using a double stent safely and effectively achieves internal biliary drainage.

Endoscopic treatment of malignant biliary strictures

Endoscopic stenting is a widely accepted strategy for providing effective drainage in both extrahepatic and intrahepatic malignant strictures. In patients with extrahepatic malignancies, uncovered self-expanding metal stents (SEMS) provide excellent palliation. Hilar malignancies are probably best palliated by placement of uncovered SEMS although some disagreement exists among experts regarding the type and number of stents for optimal palliation. Preoperative biliary drainage (PBD) is commonly performed although a higher risk of complications and the lack of clear benefit raise questions about this practice. Certain groups of patients such as those with markedly elevated bilirubin levels, and in those in whom neoadjuvant therapy is planned, are good candidates for PBD. Considerable controversy exists regarding the optimal method as well as type of stent for PBD in patients with hilar malignancies. Novel endoscopic therapies, including photodynamic therapy and radiofrequency ablation, have emerged as potential adjuvant therapies in the management of malignant bile duct strictures but need further long-term evaluation to establish survival benefit. This review focuses on the current status of endoscopic therapies for malignant biliary obstructions.

No benefit of endoscopic sphincterotomy before biliary placement of self-expandable metal stents for unresectable pancreatic cancer

BACKGROUND & AIMS

Endoscopic sphincterotomy (ES) is performed routinely before self-expandable metallic stents (SEMS) are placed in malignant distal biliary strictures to prevent postprocedural pancreatitis. However, it is not clear whether ES actually prevents pancreatitis or affects other adverse events (AEs). We conducted a noninferiority trial to examine the necessity of ES before SEMS placement.

METHODS

Two hundred patients with distal biliary strictures caused by unresectable pancreatic cancer were assigned randomly to groups that received ES or did not receive ES (non-ES) before SEMS placement, at 25 hospitals in Hokkaido, Japan, from August 2010 through November 2012. The primary outcome was early AEs (≤30 d) specifically related to the presence or absence of ES (pancreatitis, bleeding, or perforation). Secondary outcomes measured included the effect of ES omission on time to SEMS dysfunction and patient survival times.

RESULTS

The proportions of patients with early AEs were 9.2% in the non-ES group and 10.4% in the ES group (a difference of 1.2%, noninferior). The median times to SEMS dysfunction was longer than 594 days in the non-ES group and 541 days in the ES group (P = .88). The median overall survival times were 202 in the ES group vs 255 days in the non-ES group; P = .20).

CONCLUSIONS

ES before SEMS does not affect the incidence of AEs, SEMS patency, or patient survival times. Our data provide no evidence for a benefit of ES to patients undergoing SEMS placement for a biliary stricture caused by pancreatic cancer. UMIN clinical trials registry number: 000004044.

Suprapapillary versus transpapillary stent placement for malignant biliary obstruction: which is better?

PURPOSE

To compare the complications, stent patency, and patient survival with self-expandable metal stents (SEMSs) placed above or across the sphincter of Oddi in malignant biliary obstruction.

MATERIALS AND METHODS

From January 2008 to December 2012, 155 patients were treated with percutaneous transhepatic SEMS placement. Seventy-four patients underwent suprapapillary stent placement (group A), and 81 patients underwent transpapillary stent placement (group B). Complications rates, stent patency, and patient survival were evaluated and analyzed for potential predictors.

RESULTS

In group A, 68 covered and 28 uncovered SEMSs were placed, and, in group B, 78 covered and 19 uncovered SEMSs were placed. Thirty-six stent-related early complications were observed in a total of 154 patients (23.4%): pancreatitis (n = 23), cholangitis (n = 12), and cholecystitis (n = 1). The early complication rates for groups A and B were 14.9% (11 of 74) and 31.3% (25 of 80), respectively (P = .016). Pancreatitis occurred in three patients (4.1%) in group A and 20 patients (25.0%) in group B (P = .001). Stent location was a single independent predictor of pancreatitis (P < .001). Stent occlusions by tumor growth was more frequently observed in group A than in group B (P = .007), whereas stent occlusion by sludge incrustation was more frequently found in group B than in group A (P = .007). There was no significant difference in cumulative stent patency (P = .401) or patient survival (P = .792) between groups.

CONCLUSIONS

To decrease the incidence of pancreatitis, suprapapillary placement of SEMSs is recommended for malignant biliary obstruction, but not in the lower 2 cm of the common bile duct.

Endoscopic retrograde cholangiopancreatography (ERCP)-related adverse events: post-ERCP pancreatitis

Post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP) is the most common complication of endoscopic retrograde cholangiopancreatography (ERCP), and not uncommonly is the reason behind ERCP-related lawsuits. Patients at high risk for PEP include young women with abdominal pain, normal liver tests, and unremarkable imaging. Procedure-related factors include traumatic and persistent cannulation attempts, multiple injections of the pancreatic duct, pancreatic sphincterotomy, and, possibly, use of precut sphincterotomy. Aggressive hydration, use of rectal indomethacin, and prophylactic pancreatic stenting can diminish the risk (and likely severity) of PEP. Though hugely beneficial, these measures do not supersede careful patient selection and technique.

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).

METHODS

PubMed, EMBASE, Cochrane Library, and Science Citation Index databases up to March 2014 were searched. The primary outcome was incidence of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) and successful stent insertion rate. The secondary outcomes were the incidence of post-ERCP bleeding, stent migration and occlusion. The free software Review Manager was used to perform the meta-analysis.

RESULTS

Three studies (n = 338 patients, 170 in the EST group and 168 in the non-EST group) were included. All three studies described a comparison of baseline patient characteristics and showed that there were no statistically significant differences between the two groups. Three RCTs, including 338 patients, were included in this meta-analysis. Most of the analyzed outcomes were similar between the groups. Although EST reduced the incidence of PEP, it also led to a higher incidence of post-ERCP bleeding (OR = 0.34, 95%CI: 0.12-0.93, P = 0.04; OR = 9.70, 95%CI: 1.21-77.75, P = 0.03, respectively).

CONCLUSION

EST before stent placement may be useful in reducing the incidence of PEP. However, EST-related complications, such as bleeding and perforation, may offset this effect.

Risk factors for covered metallic stent migration in patients with distal malignant biliary obstruction due to pancreatic cancer

BACKGROUND AND AIM

Covered metallic stents (CMSs) were developed to overcome tumor ingrowth in uncovered metallic stents (UMSs) for malignant biliary obstruction, but superiority of CMSs over UMSs is still controversial due to the high migration rate in CMS. Therefore, we conducted this retrospective analysis to clarify risk factors for stent migration, including mechanical properties of CMSs.

METHODS

Patients with unresectable pancreatic cancer, receiving CMS for distal malignant biliary obstruction in five tertiary care centers, were retrospectively studied. Univariate and multivariate analyses to identify prognostic factors for early (< 6 months) stent migration were performed using a proportional hazards model with death or stent occlusion without stent migration as a competing risk. Two mechanical properties were included in the analysis: axial force, the recovery force that leads to a CMS straightening, and radial force (RF), the expansion force against the stricture.

RESULTS

Among 290 patients who received CMS placement for distal malignant biliary obstruction, stent migration rate was 15.2%. CMS migrated early (< 6 months) in 10.0% and distally in 11.7%, respectively. In the multivariate analysis, significant risk factors for early stent migration were chemotherapy (subdistribution hazard ratios [SHR] 4.46, P = 0.01), CMS with low RF (SHR 2.23, P = 0.03), and duodenal invasion (SHR 2.25, P = 0.02).

CONCLUSION

CMS with low RF, chemotherapy, and duodenal invasion were associated with CMS migration from our study.

Transmural biliary drainage can be an alternative to transpapillary drainage in patients with an indwelling duodenal stent

BACKGROUND

Self-expandable metal stents (SEMS) are widely utilized to relieve symptoms of malignant gastric outlet obstruction (GOO), but GOO is frequently complicated by nonresectable distal biliary obstruction. The optimal endoscopic approach to biliary drainage in this setting remains controversial and has yet to be resolved.

AIMS

To compare the safety and efficacy of endoscopic ultrasound-guided transmural biliary drainage (EUS-BD) and transpapillary drainage in patients with an indwelling duodenal SEMS.

METHODS

Patients who underwent EUS-BD or transpapillary drainage for distal malignant biliary obstruction with an indwelling duodenal SEMS between June 2007 and August 2012 at three Japanese tertiary referral centers were identified retrospectively. We compared times to stent dysfunction, causes of dysfunction, and procedural related complications between these two groups.

RESULTS

Twenty patients were included in the study (7 EUS-BD and 13 transpapillary drainage). EUS-BD was performed via hepaticogastrostomy using a SEMS in three patients and via choledochoduodenostomy using a SEMS or a plastic stent in two patients each. Transpapillary drainage was performed using a SEMS in all patients. The stent patency rate in the EUS-BD group was higher than that in the transpapillary drainage group (100 vs. 71% at 1 month and 83 vs. 29% at 3 months, respectively). The rate of stent dysfunction in the EUS-BD group tended to be lower than that in the transpapillary group (14 vs. 54%; P = 0.157). Complication rates were similar between the groups (P = 1.000), with moderate bleeding in one patient in the EUS-BD group and mild pancreatitis in one patient in the transpapillary group.

CONCLUSION

Endoscopic ultrasound-guided transmural biliary drainage is an alternative to transpapillary drainage in patients with an indwelling duodenal SEMS.

Metallic stent with high axial force as a risk factor for cholecystitis in distal malignant biliary obstruction

BACKGROUND AND AIM

Tumor involvement to the orifice of cystic duct (OCD) is a risk factor for cholecystitis after self-expandable metallic stent (SEMS) placement, but its prevention is still difficult. We conducted this multicenter analysis to clarify a type of SEMS or a method to place SEMS which would decrease the incidence of cholecystitis after SEMS placement.

METHODS

The incidence of cholecystitis was studied in consecutive patients receiving SEMS for distal malignant biliary obstruction in five tertiary care centers. Multiple logistic regression analysis was performed to evaluate risk factors for cholecystitis.

RESULTS

A total of 376 patients who received SEMS placement for distal malignant biliary obstruction were analyzed. Tumor involvement to OCD was diagnosed in 25.3%. Overall incidence of cholecystitis was 6.9%. Cholecystitis was observed in 8.0% of 300 patients with covered SEMS, 16.8% of 95 patients with tumor involvement to OCD, 10.8% of 234 patients with SEMS of high axial force (AF), and 12.0% of 158 patients with SEMS length ≤ 60 mm. In the multivariate analysis, tumor involvement to OCD (odds ratio [OR] 5.40, P < 0.001), SEMSs with high AF (OR 5.33, P = 0.002), and SEMS length ≤ 60 mm (OR 3.19, P = 0.010) are risk factors. Among patients with tumor involvement to OCD, the incidence of cholecystitis in SEMS with high and low AF was 25.0% and 5.0%, respectively.

CONCLUSION

This study with an expanded cohort reconfirmed tumor involvement to OCD as a risk factor for cholecystitis after SEMS placement. SEMS with low AF might decrease cholecystitis.

Endoscopic treatment options for cholangiocarcinoma

Cholangiocarcinomas are often locally advanced or have metastasized, and at the time of diagnosis individuals often have a poor prognosis. Endoscopic treatment options traditionally include biliary decompression via stenting to allow for systemic chemotherapy and radiotherapy, with self-expanding metal biliary stents being preferred. Recent developments in locoregional therapy delivered endoscopically, such as photodynamic therapy and radiofrequency abalation, have shown promising results in improving patient survival.

Covered metal stenting for malignant lower biliary stricture with pancreatic duct obstruction: is endoscopic sphincterotomy needed?

Aims. To evaluate the need for endoscopic sphincterotomy (EST) before covered self-expandable metal stent (CSEMS) deployment for malignant lower biliary stricture with pancreatic duct obstruction. Methods. This study included 79 patients who underwent CSEMS deployment for unresectable malignant lower biliary stricture with pancreatic duct obstruction. Treatment outcomes and complications were compared between 38 patients with EST before CSEMS deployment (EST group) and 41 without EST (non-EST group). Results. The technical success rates were 100% in both the EST and the non-EST group. The incidence of pancreatitis was 2.6% in the EST, and 2.4% in the non-EST group (P = 0.51). The incidences of overall complications were 18.4% and 14.6%, respectively, (P = 0.65). Within the non-EST groups, the incidence of pancreatitis was 0% in patients with fully covered stent deployment and 3.6% in those with partially covered stent deployment (P = 0.69). In the multivariate analysis, younger age (P = 0.003, OR 12) and nonpancreatic cancer (P = 0.001, OR 24) were significant risk factors for overall complications after CSEMS deployment. EST was not identified as a risk factor. Conclusions. EST did not reduce the incidence of pancreatitis after CSEMS deployment in patients of unresectable distal malignant obstruction with pancreatic duct obstruction.

A novel, fully covered laser-cut nitinol stent with antimigration properties for nonresectable distal malignant biliary obstruction: a multicenter feasibility study

BACKGROUND/AIMS

Stent migration occurs frequently, but the prevention of complications resulting from covered self-expandable metal stents (C-SEMSs) remains unresolved. We prospectively assessed a newly developed C-SEMS, a modified covered Zeo stent (m-CZS), in terms of its antimigration effect.

METHODS

Between February 2010 and January 2011, an m-CZS was inserted into 42 patients (31 initial drainage cases and 11 reintervention cases) at a tertiary referral center and three affiliated hospitals. The laser-cut stent was flared for 1.5 cm at both ends, with a 1 cm raised bank located 1 cm in from each flared end. The main outcome of this study was the rate of stent migration, and secondary outcomes were the rate of recurrent biliary obstruction (RBO), the time to RBO, the frequencies of complications, and overall survival.

RESULTS

Of the 31 patients with initial drainage, stent migration occurred in four (12.9%, 95% confidence interval, 5.1% to 29.0%), with a mean time of 131 days. RBO occurred in 18 (58%), with a median time to RBO of 107 days. Following previous C-SEMS migration, seven of 10 patients (70%) did not experience m-CZS migration until death.

CONCLUSIONS

m-CZSs with antimigration properties effectively, although not completely, prevented stent migration after stent insertion.

Endoscopic biliary stenting and pancreatitis

Endoscopic biliary stenting across the duodenal papilla can obstruct the adjacent pancreatic orifice and disturb the flow of pancreatic juice, which may result in pancreatitis. However, the relationship of endoscopic biliary stenting to post-procedure pancreatitis has not been thoroughly examined. Therefore, we have reviewed the published literature on this issue. Although biliary stenting, especially with large-bore and self-expandable metallic stents (SEMSs), has been considered a possible additional risk factor for pancreatitis following biliary stenting, most studies have not provided convincing supporting evidence; this failure may be due to inadequate study design or insufficient numbers of subjects. It also remains unclear whether endoscopic sphincterotomy (EST) performed prior to biliary stenting decreases the incidence of post-stenting pancreatitis; some recent studies have claimed that EST is not necessary before biliary stenting, even with placement of SEMSs. Well-designed studies with a large number of subjects will be needed to clarify these issues.

Otaru consensus on biliary stenting for unresectable distal malignant biliary obstruction

Endoscopic biliary drainage with biliary stent placement is the treatment of choice for palliation in patients with malignant biliary obstruction caused by unresectable neoplasms. Various biliary stent designs have become available, but lack of a clear consensus persists on the use of covered versus uncovered metal stents in malignant distal bile duct obstructions, and plastic versus metal stents. In 2012, the European Society of Gastrointestinal Endoscopy indicated guidelines for biliary stenting. Accordingly, the consensus meeting for biliary stenting was held at the Endoscopic Forum Japan 2012, and four selected statements related to stent placement for distal malignant biliary obstruction were discussed to produce a consensus. Two of four statements (related to the usefulness of self-expandable metallic stents, and reintervention after stenting) were agreed upon by almost all participants. Nevertheless, our opinions were divided on the other two statements (necessity of sphincterotomy for stenting, and covered metal stent versus uncovered metal stent). We herein report the results of the meeting, and present proposed new statements via discussion.

Necessity for endoscopic sphincterotomy for biliary stenting in cases of malignant biliary obstruction

Endoscopic biliary stenting is a useful way to treat distal malignant biliary strictures that are not eligible for surgery. A 10-Fr plastic or metal stent is used for stenting. Typically, endoscopic sphincterotomy (EST) has often been carried out as a way to prevent pancreatitis after stent placement given the ease of stent insertion, but EST has flaws such as bleeding and stent migration.The present study describes the need for EST prior to stent placement.

Lethal post-endoscopic retrograde cholangiopancreatography pancreatitis following fully covered metal stent placement in distal biliary obstruction due to unresectable cholangiocarcinoma

Biliary self-expandable metallic stent (SEMS) is the preferred and first-line therapy for unresectable malignant biliary obstruction. To date, several reports have revealed the relatively high incidence of acute complications such as pancreatitis and cholecystitis due to mechanical stent compression. In the present case, we encountered fatal pancreatitis following fully covered metal stent placement. An 85-year-old man had middle bile duct strictures due to cholangiocarcinoma. A 10-mm diameter fully covered SEMS was placed across the papilla for biliary decompression. Laboratory data and physical evidence the following day revealed acute pancreatitis. Therefore, antibiotics and protein degeneration enzyme inhibitors were given. However, his condition did not improve. Two days after the procedure, we removed the stent and returned him to his original hospital. Serum amylase level decreased below 400 mg/dL 6 h after the procedure. However, the acute pancreatitis worsened. Although we treated the patient in the intensive care unit, he died 32 days after the second admission.

Biliary self-expandable metallic stent for unresectable malignant distal biliary obstruction: which is better: covered or uncovered?

Self-expandable metallic stents (SEMS) are a widely accepted biliary endoprosthesis for patients with unresectable malignant distal biliary obstruction. There are two types of SEMS: covered and uncovered. Uncovered SEMS (UCSEMS) embed into the biliary wall due to their mesh structure and self-expandability, and are resistant to migration. However, the disadvantage of UCSEMS is occlusion due to tumor ingrowth (TI) via the stent mesh, and TI is the main cause of UCSEMS occlusion. To overcome this, covered SEMS (CSEMS) were developed and showed longer patency than UCSEMS. However, migration due to the non-embedded stent body is the main cause of CSEMS dysfunction. There are some randomized studies comparing CSEMS and UCSEMS; however, the results are different according to each study. From one meta-analysis, CSEMS showed longer patency than UCSEMS. A literature review revealed that covered SEMS showed longer patency than UCSEMS. Some studies cannot clearly demonstrate the superiority of CSEMS, as the CSEMS used did not prevent TI or migration. Mechanical properties of SEMS may influence the occurrence of complications. A recent clinical study comparing the Covered Wallstent and the Covered WallFlex revealed superiority of the WallFlex for the prevention of migration. Reducing the axial force and increasing the radial force may lead to good results. Migration of CSEMS should be prevented by taking into consideration the mechanical properties of stents and development of anti-migration systems.

Predictive factors for pancreatitis and cholecystitis in endoscopic covered metal stenting for distal malignant biliary obstruction

BACKGROUND AND AIM

Pancreatitis and cholecystitis are major complications after self-expandable metal stent (SEMS) placement in distal malignant biliary obstruction. We aimed to clarify predictive factors for pancreatitis and cholecystitis after covered SEMS placement.

METHODS

We retrospectively reviewed 74 consecutive patients with distal malignant biliary obstruction who underwent initial endoscopic drainage using covered SEMS. Predictive factors for pancreatitis and cholecystitis were evaluated in the 74 patients described above and in 66 patients who had not undergone cholecystectomy.

RESULTS

The incidences of pancreatitis and cholecystitis were 10.8% (8/74) and 6.1% (4/66), respectively. Univariate analysis revealed that non-pancreatic cancer (P = 0.018) and contrast injection into the pancreatic duct (P = 0.030) were significant predictive factors for pancreatitis. Multivariate analysis revealed that non-pancreatic cancer (odds ratio [OR], 4.21; 95% confidence interval [CI], 1.63-14.18; P = 0.007) and contrast injection into the pancreatic duct (OR, 3.34; 95% CI, 1.33-9.60; P = 0.016) were significant independent predictive factors for pancreatitis. On the other hand, univariate and multivariate analyses revealed that tumor involvement to the orifice of the cystic duct (OCD) was a significant independent predictive factor for cholecystitis (OR, 5.85; 95% CI, 1.91-27.74; P = 0.005).

CONCLUSIONS

Non-pancreatic cancer and contrast injection into the pancreatic duct were predictive factors for pancreatitis, and tumor involvement to the OCD was a positive predictive factor for cholecystitis after endoscopic covered SEMS placement for distal malignant biliary obstruction.

Endoscopic retrograde cholangiopancreatography for distal malignant biliary stricture

Endoscopic biliary stent placement is widely accepted as palliation for malignant biliary obstruction or as a treatment of benign biliary stricture. Although various biliary stent designs have become available since self-expandable metallic stents were introduced, no single ideal stent has been developed. An ideal stent should be patent until death, or surgery, in patients with resectable malignant biliary obstruction. Fewer complications, maneuverability, cost-effectiveness, and removability are also important factors. Alternatively, should we develop a novel method for biliary drainage other than biliary stenting via endoscopic retrograde cholangiopancreatography? This article reviews the current status of biliary stenting for malignant biliary obstructions.

Comparison of partially covered nitinol stents with partially covered stainless stents as a historical control in a multicenter study of distal malignant biliary obstruction: the WATCH study

BACKGROUND

Covered self-expandable metal stents (CSEMSs) were developed to prevent tumor ingrowth, but stent migration is one of the problems with CSEMSs.

OBJECTIVE

To evaluate a new, commercially available CSEMS with flared ends and low axial force compared with a commercially available CSEMS without the anti-migration system and high axial force.

DESIGN

Multicenter, prospective study with a historical cohort.

SETTING

Twenty Japanese referral centers.

PATIENTS

This study involved patients with unresectable distal malignant biliary obstruction.

INTERVENTION

Placement of a new, commercially available, partially covered SEMS.

MAIN OUTCOME MEASUREMENTS

Recurrent biliary obstruction rate, time to recurrent biliary obstruction, stent-related complications, survival.

RESULTS

Between April 2009 and March 2010, 141 patients underwent partially covered nitinol stent placement, and between May 2001 and January 2007, 138 patients underwent placement of partially covered stainless stents as a historical control. The silicone cover of the partially covered nitinol stents prevented tumor ingrowth. There were no significant differences in survival (229 vs 219 days; P = .250) or the rate of recurrent biliary obstruction (33% vs 38%; P = .385) between partially covered nitinol stents and partially covered stainless stents. Stent migration was less frequent (8% vs 17%; P = .019), and time to recurrent biliary obstruction was significantly longer (373 vs 285 days; P = .007) with partially covered nitinol stents. Stent removal was successful in 26 of 27 patients (96%).

LIMITATIONS

Nonrandomized, controlled trial.

CONCLUSION

Partially covered nitinol stents with an anti-migration system and less axial force demonstrated longer time to recurrent biliary obstruction with no tumor ingrowth and less stent migration.