Endoscopic Bilio-Duodenal Bypass: Outcomes of Primary and Revision Efficacy of Combined Metallic Stents in Malignant Duodenal and Biliary Obstructions

Background

Self-expandable metal stents (SEMSs) can be used for palliation of combined malignant biliary and duodenal obstructions. However, the results of the concomitant stent placement for the duration of the patients’ lives, as well as the need for and efficacy of endoscopic revision, are unclear.

Aim

This study evaluated the clinical effectiveness of SEMS placement for combined biliary and duodenal obstructions throughout the patients’ lives and the need for endoscopic revision.

Methods

This study is a retrospective multicenter study of 50 consecutive patients who underwent simultaneous or sequential SEMS placement for malignant biliary and duodenal obstructions. The data were collected to analyze the sustained relief of obstructive symptoms until the patients’ death and the efficacy of endoscopic revision, as well as stent patency, adverse events, survival and prognostic factors for stent patency.

Results

Technical and immediate clinical success was achieved in all of the patients. Duodenal stricture occurred before the papilla in 35 patients (70 %), involved the papilla in 11 patients (22 %) and was observed distal to the papilla in four patients (8 %). Initial biliary stenting was performed endoscopically in 42 patients (84 %) and percutaneously in eight patients. After combined stenting, 30 patients (60 %) required no additional intervention until the time of their death. The remaining 20 patients were successfully treated using endoscopic stent reinsertion: nine patients needed biliary revision, three patients needed duodenal restenting and eight patients needed both biliary and duodenal reinsertion. The median duodenal stent patency and median biliary stent patency were 34 and 27 weeks, respectively. The median survival after combined stent placement was 18 weeks. A Cox multivariate analysis showed that duodenal stent obstruction after combined stenting was a risk factor for biliary stent obstruction (hazard ratio 6.85; 95 % confidence interval 1.43–198.98; P = 0.025).

Conclusions

Endoscopic bilio-duodenal bypass is clinically effective, and the majority of the patients need no additional intervention until their death. Endoscopic revision is feasible and has a high success rate.     

Efficacy of a Metallic Stent Covered with a Paclitaxel-Incorporated Membrane Versus a Covered Metal Stent for Malignant Biliary Obstruction: A Prospective Comparative Study

Background

The placement of a self-expandable metallic stent (SEMS) is a widely used nonsurgical treatment method in patients with unresectable malignant biliary obstructions but SEMS is susceptible to occlusion by tumor ingrowth or overgrowth.

Aim

The efficacy and safety of a metallic stent covered with a paclitaxel-incorporated membrane (MSCPM) in which paclitaxel provided an antitumoral effect was compared prospectively with those of a covered metal stent (CMS) in patients with malignant biliary obstructions.

Methods

Patients with unresectable distal malignant biliary obstructions (n = 106) were prospectively enrolled in this study at multiple treatment centers. A MSCPM was inserted endoscopically in 60 patients, and a CMS was inserted in 46 patients. Patients underwent systemic chemotherapy regimens alternatively according to disease characteristics.

Results

The two groups did not differ significantly in mean age, male to female ratio, or mean follow-up period. Stent occlusion due to tumor ingrowth occurred in 12 patients who received MSCPMs and in eight patients who received CMSs. Stent patency and survival time did not differ significantly between the two groups (p = 0.116, 0.981). Chemotherapy had no influence on stent patency, but gemcitabine-based chemotherapy was a significant prognostic factor for survival time (p = 0.012). Complications, including cholangitis and pancreatitis, were found to be acceptable in both groups.

Conclusions

Although the use of a MSCPM produced no significant differences in stent patency or patient survival in patients with malignant biliary obstructions compared with the use of a CMS, this study demonstrated that MSCPM can be used safely in humans.     

Technical Feasibility and Revision Efficacy of the Sequential Deployment of Endoscopic Bilateral Side-by-Side Metal Stents for Malignant Hilar Biliary Strictures: A Multicenter Prospective Study

Background

Theoretically, the side-by-side bilateral placement of metal stents may be technically easier than stent-in-stent bilateral placement in stent revision. However, side-by-side placement can be technically challenging, as the deployment of the first stent can preclude the passage of the second stent.

Aim

We explored the technical feasibility and revision efficacy of endoscopic bilateral side-by-side stent placement for malignant hilar biliary strictures.

Methods

Forty-four patients with Bismuth type II or higher malignant hilar biliary strictures were enrolled in seven academic tertiary referral centers. Endoscopic placement of side-by-side bilateral metal stents with 7F thin delivery shaft was performed. The outcome measurements were the technical and functional success, adverse events, endoscopic revision success rate, and stent patency.

Results

Overall, the technical and functional success rates were 91 % (40/44), and 98 % (39/40), respectively. Two of the failed patients were converted successfully with subsequent contralateral stent-in-stent placement, and the other patients underwent percutaneous intervention. Early stent-related adverse events occurred in 10 %. The endoscopic revision rate due to stent malfunction during follow-up (median: 180 days) was 45 % (18/40; tumor ingrowth in 4 and in-stent sludge impaction/stone formation in 14 patients). The endoscopic revision success rate was 92 % (12/13). Five patients with comorbidity underwent initial percutaneous intervention. The median survival and stent patency periods were 180 and 157 days, respectively.

Conclusions

The sequential placement of a metal stent with a 7F thin delivery shaft in bilateral side-by-side procedures may be feasible and effective for malignant hilar biliary strictures and for endoscopic stent revision.     

The Stent Patency and Migration Rate of Different Shaped Plastic Stents in Bile Flow Phantom Model and In Vivo Animal Bile Duct Dilation Model

Background/Aim

In research and development of biliary plastic stents (PS), continuous efforts have been made to overcome short patency time and high rate of migration. The aim of this study was to evaluate the patency and migration rate of different PS shapes for a given period of time.

Methods

Using an in vitro bile phantom model, we compared the patency among different shapes of PS (three straight PS, four double-pigtail PS, and a new screw-shaped PS). We performed an analysis of the degree of luminal narrowing by light microscopic examination. Using an in vivo swine model, we compared the patency and migration rate among the three different types of PS.

Results

Eight weeks after the bile exposure in the bile flow phantom model, 80 PS were retrieved and analyzed. The straight PS showed less biofilm formation and luminal narrowing than other types of PS (p < 0.05). Forty-nine PS were inserted into the dilated bile ducts of 10 swine models, and 39 PS were successfully retrieved 8 weeks later. The stent migration occurred less frequently in the double-pigtail PS and the screw-shaped PS than it did in the straight PS (11.1, 10, and 27.3%, respectively). However, there was no statistical difference in stent patency among the different shapes.

Conclusions

Stent patency may not be significantly different depending on the shape of PS for 8 weeks. The screw-shaped PS showed similar patency and migration rate to the double-pigtail PS. These results may help guiding future PS development and clinical decisions.

     

Endoscopic placement of a new short-term biodegradable pancreatic and biliary stent in an animal model: a preliminary feasibility study (with videos)

Background and purpose

Recently, biodegradable pancreatic stents have been designed and placed in vivo and in vitro. The aim of this study is to investigate the feasibility of endoscopic stenting using the novel, braided, self-expandable, biodegradable, pancreatic and biliary stent in a pig model.

Methods

A braided, self-expandable, biodegradable stent was endoscopically placed into the pancreatic duct and bile duct in 4 pigs. Eventually, necropsy was performed to evaluate the stent placement after the procedure.

Results

Pancreatic and biliary stents were successfully inserted and easily deployed across the papilla into the main pancreatic duct and bile duct, respectively, in all the animals under endoscopic and fluoroscopic guidance. Necropsy performed immediate following stent placement, found that stents had been placed across the papilla and stent expansion had occurred in all cases.

Conclusions

Although this stent is not radiopaque and the number of cases was small in this experimental study, endoscopic stenting using this novel, braided, self-expandable, biodegradable, pancreatic and biliary stent was feasible in the pig model. Further animal studies to evaluate the short-term patency, tissue reactivity and degradability of the stents are warranted.     

Favorable clinical outcome using a covered stent following transjugular intrahepatic portosystemic shunt in patients with portal hypertension

Aims

To compare retrospectively the clinical outcomes in patients treated with transjugular intrahepatic portosystemic shunt (TIPS) using the novel polytetrafluoroethylene-covered stents (Fluency) and bare stents.

Materials and methods

Sixty consecutive patients with portal hypertension treated with TIPS from April 2007 to April 2009 were included. TIPS creation was performed with Fluency stent grafts in 30 patients (group A) and with bare stents in 30 patients (group B). Liver function, TIPS patency and clinical outcomes were evaluated every 3 months after procedures.

Results

During hospitalization, there were no cases of hepatic encephalopathy (HE) and recurrence of variceal bleedings. Acute shunt occlusion was found in one patient in each group. Follow-ups were performed in group A with average time of 6.16 ± 3.89 months and in group B with 8.34 ± 4.42 months. The rates of recurrent bleeding, shunt occlusion, HE and mortality were 0.03, 0.0, 16.7 and 0% in group A, and 20.0, 30.0, 20.0 and 13.3% in group B, respectively. There was no difference of HE between group A and group B. The decrease of portal pressure and portosystemic pressure gradient, and the increase of portal flow were 34.1 and 23.3%, 60.0 and 52.8%, and 189.5 and 111.1% in group A and B, respectively. There were no differences of liver function between group A and B.

Conclusion

The Fluency stent graft is relatively safe and effective in TIPS creation, with a high patency rate compared with bare stents.     

Long-Term Risk of Cholangitis in Patients with Metal Stents for Malignant Biliary Obstruction

Background

Patients with malignant biliary obstruction are commonly living longer than previously due to improved oncologic therapies, often exceeding expected times of self-expanding metal stent patency.

Aims

The purpose of this study was to assess the long-term risk and impact of cholangitis in these patients.

Methods

Retrospective review of electronic medical records at an academic medical center.

Results

One hundred and one patients had a self-expanding metal stent placed for malignant biliary obstruction. The median survival after SEMS was 214 days. Of these patients, 22 % developed at least one episode of cholangitis requiring inpatient admission, 20 % (9/45) of patients were hospitalized for cholangitis at 6 months, 40 % (8/20) at 1 year, and 75 % (3/4) at 2 years. All of the (8/8) patients receiving chemotherapy prior to hospitalization for cholangitis experienced delays in subsequent chemotherapy. Follow-up of 36 episodes of cholangitis revealed a 14 % 30-day mortality.

Conclusions

Cholangitis develops commonly in long-term survivors with self-expanding metal stents for malignant biliary obstruction, and is associated with delays in chemotherapy and a 14 % 30-day mortality.     

Long-term fecal diverting device for the prevention of sepsis in case of colorectal anastomotic leakage: an animal experiment

Background

A new fecal diverting device (FDD) was fabricated for fecal diversion from the proximal colon above the anastomosis to outside the anus for protecting the rectal anastomosis. The aim of the study is to evaluate the safety and effectiveness of the FDD.

Methods

After a pilot study, a prospective observational trial was performed in 34 mongrel dogs. The experiment comprised of segmental resection and anastomosis of the colon, fixation of the FDD, and observation for 3 weeks (n?=?15) and more than 3 weeks (n?=?19) without initiation of parenteral nutrition.

Results

Four cases of perioperative death unrelated to the FDD were excluded. Twenty-six (87 %) of the 30 dogs survived. Sixteen (53 %) dogs were able to retain the FDD for more than 3 weeks until 82 days. The autopsy findings revealed that four (15 %) dogs showed colonic wall erosions and mucosal scarring respectively at the band fixation area without evidence of serious septic complications. The surviving dogs retained the FDD for more than 6 days. Mortality occurred in four of the five dogs that expelled the FDD within three postoperative days. A closed abscess cavity as the evidence of anastomotic leakage was noted in seven (23 %) of the surviving dogs.

Conclusions

The newly designed fecal diverting device can be retained for more than 3 weeks until 82 days without any serious complications. The FDD may prevent sepsis in case of anastomotic leakage if it is retained for more than 6 days.     

Endoscopic stent placement above the intact sphincter of Oddi for biliary strictures after living donor liver transplantation

Background and study aims

Biliary complications are one of the most serious morbidities after liver transplantation. Inside-stent is a plastic stent placed above the sphincter of Oddi without endoscopic sphincterotomy against biliary strictures. Our aims were to analyze the long-term efficacy of inside-stent placement in patients with biliary stricture after living donor liver transplantation.

Patients and methods

Ninety-four patients who experienced biliary stricture that employed duct-to-duct reconstruction were treated with inside-stent placement. Treatment outcomes, including stricture resolution, recurrence, inside-stent patency, and morbidity rate were evaluated retrospectively.

Results

Ninety-two patients could be evaluated. Resolution of stricture was eventually observed in 81 of 92 patients with an average of 1.4 sessions of endoscopic retrograde cholangiography. Of the 81 patients who achieved the resolution of the stricture, recurrent biliary stricture that required intervention occurred in 8 patients. Conversely, stricture remission was achieved 73 patients (90.1 %) during 53 months follow-up after stent removal. Median duration of patency of the initial stent was 189 (range 2–1228) days. Stent dislocation occurred in 10 patients. Adverse event related to inside-stent placement was pancreatitis in 18 cases (mild 13, moderate 5).

Conclusions

Inside-stent placement achieved long-term patency and high remission rate in patients with biliary stricture after liver transplantation.     

Percutaneous Transhepatic Treatment Using Retrievable Covered Stents in Patients with Benign Biliary Strictures: Mid-term Outcomes in 68 Patients

Background

Percutaneous balloon dilation of benign biliary stricture has been the most widely used alternative to endoscopic treatment; however, the rate of recurrence has varied from 15 to 44 %. Recently, several investigators have reported that percutaneous transhepatic placement of retrievable covered stents is feasible for the treatment of benign biliary strictures. However, these studies had only a small number of patients and had short follow-up periods.

Aim

The purpose of this study was to investigate the mid-term outcomes of a retrievable covered stent for treatment of benign biliary strictures.

Methods

We retrospectively assessed 68 patients who underwent percutaneous transhepatic placement and removal of a retrievable covered stent between March 2007 and November 2012, for treatment of benign biliary strictures. Forty-two patients had not previously undergone interventional treatment, whereas 26 had recurrent or refractory strictures despite previous percutaneous procedures.

Results

Placement of the retrievable covered stents was technically successful in all patients. Stent migration occurred in 11 (16.2 %) patients. The mean indwelling period of drainage catheter and stent were 5.8 months (range, 3–22.5 months) and 3 months (range, 2–6.5 months), respectively. Clinical success was achieved in 59 (86.8 %) patients. During the mean follow-up of 36 months (range, 8.5–65 months), 12 (20 %) of 60 patients had recurrence of clinically significant strictures. The primary patency rates at 1, 2, 3, 4, and 5 years were 91, 89, 76, 68, and 68 %, respectively.

Conclusion

Mid-term outcomes suggested that percutaneous treatment of benign biliary strictures using a retrievable covered stent was a clinically effective method.     

Metallic stents are more efficacious than plastic stents in unresectable malignant hilar biliary strictures: a randomized controlled trial

Background

Endoscopic biliary stenting is a well-established palliative treatment for unresectable malignant biliary strictures, for which plastic tube stents (PSs) and self-expandable metallic stents (SEMSs) are most commonly used. The efficacy of these stents has been extensively described in distal biliary strictures, but not in hilar biliary strictures. The present study aimed to compare the efficacy of PSs and SEMSs for unresectable malignant hilar biliary strictures.

Methods

From June 2004 to November 2008, 60 patients were enrolled and prospectively randomized into the PS or SEMS group.

Results

The 6-month patency rate was significantly higher in the SEMS group than in the PS group (81 vs. 20%; p = 0.0012). Kaplan–Meier analysis showed significantly longer patency in the SEMS group than in the PS group (p = 0.0002); the 50% patency period was 359 days in the SEMS group and 112 days in the PS group. There was no significant difference in the overall survival period between the PS and SEMS groups (p = 0.2834). The mean number of reinterventions for stent failures was significantly lower in the SEMS group (0.63 times/patient) than in the PS group (1.80 times/patient) (p = 0.0008). The overall total cost for the treatment was significantly lower in the SEMS group than in the PS group (p = 0.0222).

Conclusions

SEMSs were associated with a longer patency than PSs in patients with unresectable hilar biliary stricture. SEMSs were also more advantageous in reducing the number of reintervention sessions and the overall treatment cost.     

Obstructive sleep apnea in Asian primary school children

Purpose

The objectives of this study were to examine the prevalence of obstructive sleep apnea (OSA) in primary school children, relationships between OSA and tonsillar hypertrophy, adenoid, and patency of the nasal cavity, and the effects of the tonsillar hypertrophy and adenoid on the nasal patency.

Methods

An examination of the palatine tonsils and anterior rhinoscopy, completion of a questionnaire survey, a measurement of nasal resistance, an examination for sleep apnea at home using portable polysomnography device, and radiography of pharyngeal tonsil were performed in 152 primary school children.

Results

The obstructive apnea hypopnea index (O-AHI) increased with enlargements in the palatine tonsils. The adenoidal nasopharyngeal ratio (A/N ratio) decreased with advances in grade. A significant difference was observed in the O-AHI between those with and without adenoid. The median value of the O-AHI increased with advances in grade. The nasal resistance was significantly higher in the group with adenoid compared as in the group without. It was also higher in the nasal disease group with OSA than in the group without. Full polysomnography(PSG) was recommended in 16 (10.5 %) of 152 who underwent the examination using the portable polysomnography device, and of the eight who underwent PSG, six (75 %) were confirmed to have OSA, while its prevalence in all subjects was estimated as 7.9 %.

Conclusions

Disturbances in nasal respiration as well as tonsillar hypertrophy and adenoid were found to be a risk factor of OSA in primary school children.     

Long-Term Follow-Up of TIPS Created with Expanded Poly-Tetrafluoroethylene Covered Stents

Background

Transjugular intrahepatic portosystemic shunts (TIPS) created with expanded poly-tetrafluoroethylene-covered stents have largely replaced bare metal stents. Short-term shunt patency is typically assessed with protocol Doppler ultrasound (US), while little information exists with regard to long-term patency.

Aim

We investigated the value of Doppler US in assessing TIPS patency as well as long-term clinical outcomes.

Methods

A retrospective analysis of 59 patients with covered stents used for TIPS between January 2001 and December 2011 was performed.

Results

Fifty-four patients had early (median 9 days) Doppler US follow-up. Seven of eight patients with an abnormal baseline US required stent revisions. None of the 46 patients with normal baseline Doppler US required revisions within the first 6 months; six of these patients subsequently had a portogram because of symptoms, but all TIPS were patent. Fifty-two patients survived for long-term (>6 months) follow-up, averaging 654 days and three Doppler US exams. Five of six patients with abnormal follow-up Doppler US required revisions, whereas none of the 46 patients with normal follow-up US had revisions. The recurrence of symptoms of portal hypertension and/or hepatic encephalopathy (HE) was low (4/52 patients). No significant predictors of long-term stenosis were identified. Post-TIPS HE was independent of pre-TIPS HE or Child-Pugh score.

Conclusions

Short-term patency and that at approximately 2 years after TIPS placement was 87 and 77 %, respectively. We conclude that Doppler US at least 1 week after TIPS is warranted, but repeated Doppler US follow-up is probably not necessary in the absence of clinical symptoms.     

Enemas with n-Acetylcysteine Can Reduce the Level of Oxidative Damage in Cells of the Colonic Mucosa Diverted from the Faecal Stream

Background

Oxidative stress has been related to inflammation of the colonic mucosa in patients with diversion colitis (DC).

Aim

The purpose of this study was to evaluate the antioxidants effects of n-acetylcysteine (NAC) in colon segments without faecal stream.

Methods

Thirty-six Wistar rats were subjected to diversion of the faecal stream by proximal colostomy and a distal mucosal colon fistula. They were distributed into three experimental groups of 12 animals each; the animals in each group underwent daily enemas containing saline solution (control group) or either a 25 or 100 mg/kg dose of NAC (treated groups). In each group, animals were sacrificed after 2 or 4 weeks. The degree of inflammation was determined by histopathological analysis and stratified by inflammatory grading scale. Oxidative DNA damage was measured by comet assay. The Mann–Whitney test and ANOVA were used for statistical analysis; p < 0.05 was considered significant.

Results

The oxidative DNA damage in colon segments without faecal stream was significantly lower in animals treated with either concentration of NAC than in control group, regardless of the duration of intervention (p < 0.01).

Conclusions

Intrarectal application of NAC reduces the inflammation as well as DNA oxidative damage and could be beneficial as a complementary agent in the treatment of DC.     

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.     

Multicenter study evaluating factors for stent patency in patients with malignant biliary strictures: development of a simple score model

Background

Self-expanding metal stents (SEMS) are known to have a significantly higher patency rate than plastic stents. We aimed to identify prognostic factors, besides stent type, for stent patency and to develop a score model that could further aid in guiding stent choice for the palliation of a malignant biliary stricture.

Methods

A retrospective multicenter study was conducted. Data on consecutive patients who had a stent placed between January 2002 and July 2009 were collected. Cumulative stent occlusion rates were analyzed by Kaplan?CMeier curves and log rank testing, and prognostic factors were assessed by Cox regression analysis.

Results

A total of 690 stents (512 plastic stents, 174 SEMS) were endoscopically placed in 390 patients. At 8?weeks, stent occlusion had occurred in 32% of the plastic stents and 11% of the SEMS. Multivariate analysis indicated that plastic stents (hazard ratio [HR] 2.5, 95% confidence interval [CI] 1.9?C3.5), a tight stricture requiring preceding dilation (HR 1.8, 95% CI 1.3?C2.5), and a high initial bilirubin level (>50???mol/L (HR 1.3, 95% CI 1.0?C1.7) were independently associated with an increased risk of stent occlusion. A score model based on these 3 factors was able to distinguish between stent procedures with a relatively high and low risk of stent occlusion (median 14 vs. 26?weeks, respectively).

Conclusion

Besides plastic stents, stricture severity requiring preceding dilation, and initial higher bilirubin level were associated with a shorter period of stent patency. A simple score model based on these factors was able to predict stent occlusion and may aid in choosing the most appropriate stent type in individual patients.     

Biliary Stenting in Patients with Malignant Biliary Obstruction: Comparison of Double Layer, Plastic and Metal Stents

Background and Aim

The double layer stent (DLS) has a unique design and has been used for palliation of malignant biliary obstruction, but literature on this stent is limited. Our aim was to compare plastic (PS), DLS and metal stents (MS) in terms of complication rates, time to occlusion, and patency rate in patients with malignant biliary obstruction (MBO).

Methods

A retrospective review of stents placed for MBO at our institution in the period between January 2009 and April 2011 was conducted. A total of 114 stents were identified, of which 44 were MS (39 %), 37 DLS (32 %), and 33 PS (29 %). A stent was considered occluded when an unplanned stent removal or intervention occurred due to clinical suspicion of biliary obstruction.

Results

Stents remained patent for 95 days (range 7–359 days) in the DLS group and 59 days (range 7–228 days) in the PS group (P = 0.014) and 128.7 days (range 4–602 days) in the metal stent group. Twenty-seven percent (n = 9) of PS occluded after a mean of 60 days while 16 % (n = 7) of MS occluded after a mean of 87 days and 5 % (n = 2) of DLS occluded after a mean of 85 days (DLS vs. PS P = 0.012, DLS vs. MS P = 0.13, MS vs. PS P = 0.22).

Conclusions

DLS are superior to PS in patients with MBO and appear to be comparable to MS. MS had a longer patency rate but were comparable to DLS in early and late complications. We speculate that the less expensive DLS may be a cost effective alternative in the palliation of MBO.     

Activation of alpha-smooth muscle actin-positive myofibroblast-like cells after chemotherapy with gemcitabine in a rat orthotopic pancreatic cancer model

Background

To investigate the behavior of activated pancreatic stellate cells (PSCs), which express alpha-smooth muscle actin (α-SMA), and pancreatic cancer cells in vivo, we examined the expression of α-SMA-positive myofibroblast-like cells in pancreatic cancer tissue after treatment with gemcitabine (GEM) using a Lewis orthotopic rat pancreatic cancer model.

Methods

The effect of GEM on DSL-6A/C1 cell proliferation was determined by cell counting method. The orthotopic pancreatic cancer animals were prepared with DSL-6A/C cells, and treated with GEM (100 mg/kg/weekly, for 3 weeks). At the end of treatment, α-SMA expression, fibrosis, transforming growth factor (TGF)-β1 and vascular endothelial growth factor (VEGF) were evaluated by histopathological and Western blot analyses.

Results

DSL-6A/C1 cell proliferation was significantly reduced by co-culturing with GEM in vitro. Survival time of pancreatic cancer animals (59.6 ± 13.4 days) was significantly improved by treatment with GEM (89.6 ± 21.8 days; p = 0.0005). Alpha-SMA expression in pancreatic cancer tissue was significantly reduced after treatment with GEM (p = 0.03), however, there was no significant difference in Sirius-red expression. Expression of VEGF was significantly reduced by GEM treatment, but the expression of TGF-β1 was not inhibited.

Conclusion

GEM may suppress not only the tumor cell proliferation but also suppress PSCs activation through VEGF reduction.     

Palliative Stent for Malignant Colonic Obstruction by Extracolonic Malignancy: A Comparison with Colorectal Cancer

Background and Aim

Palliative self-expandable metal stent placement for colonic obstruction arising from an extracolonic malignancy might be as useful as that for colorectal cancer, but data are limited. The purposes of this study were to investigate success and complications of stent placement in patients with extracolonic malignancy and to compare long-term clinical outcomes for an extracolonic malignancy group with those for a colorectal cancer group.

Patients and methods

We reviewed short-term and long-term outcomes for patients treated with palliative stents for colonic obstruction by extracolonic malignancy (n = 44) or unresectable colorectal cancer (n = 53) from January 2006 to March 2011.

Results

Neither the technical success (93.2 vs. 98.1 %, respectively; P = 0.326) nor clinical success (77.3 vs. 84.9 %, respectively; P = 0.433) of stent placement differed significantly in the two groups. Complications as a result of stent placement also differed only slightly in the two groups (perforation: 4.8 % (two cases) vs. 0 %, respectively; migration: 4.8 vs. 5.8 %, respectively, P = 0.343). With regard to long-term outcomes, although stent patency was shorter in the extracolonic malignancy group (P = 0.015), because overall survival in this group was also shorter (P = 0.018), it was sufficient for palliative purposes.

Conclusions

Palliative stent placement was equally effective and safe for treatment of colonic obstruction arising from either extracolonic malignancy or unresectable colorectal cancer. Even in cases of colonic obstruction arising from extracolonic malignancy, stent placement should be considered as primary palliative therapy.     

Bilateral Metal Stents for Hilar Biliary Obstruction Using a 6Fr Delivery System: Outcomes Following Bilateral and Side-by-Side Stent Deployment

Background and Study Aim

Controversy exists on optimal endoscopic management for palliation of malignant hilar obstruction, with advocates for metal “side-by-side” (SBS) and “stent-in-stent” (SIS) techniques. We sought to evaluate the technical feasibility, efficacy, and outcomes of bilateral biliary self-expanding metal stents (SEMS) for treatment of malignant hilar obstruction using a stent with a 6Fr delivery system.

Patients and Methods

This was a single-center, retrospective review of all patients who underwent bilateral placement of Zilver^® biliary SEMS for malignant hilar obstruction from January 2010 to August 2012. Patients underwent endoscopic retrograde cholangiopancreatography with placement of stents using either the SIS or SBS stent techniques.

Results

Twenty-four patients (19 men, mean age 63 years) underwent bilateral stenting for malignant hilar obstruction during the study period. Seventeen and seven patients underwent the SBS and SIS technique, respectively. Cholangiocarcinoma (n = 14) was the most common cause of hilar obstruction. Initial technical success was achieved in 24/24 (100 %) of patients; however, 12 (50 %) patients required re-intervention during the study period (median 98 days). Comparison of the SBS and SIS groups revealed no statistical difference with respect to need for re-intervention (P = 0.31), successful re-intervention (P = 0.60), or procedural length (P = 0.89).

Conclusions

Use of bilateral Zilver^® SEMS in either the SBS or SIS configuration is safe, technically feasible, and effective for drainage of malignant hilar obstruction; however, duration of stent patency and procedure-free survival remain variable.