Use of a specially designed partially covered self-expandable metal stent (PSEMS) with a 40-mm diameter for the treatment of upper gastrointestinal suture or staple line leaks in 11 cases

Introduction

The use of self-expandable stents to treat postoperative leaks and fistula in the upper gastrointestinal (GI) tract is an established treatment for leaks of the upper GI tract. However, lumen-to-stent size discrepancies (i.e., after sleeve gastrectomy or esophageal resection) may lead to insufficient sealing of the leaks requiring further surgical intervention. This is mainly due to the relatively small diameter (≤30 mm) of commonly used commercial stents. To overcome this problem, we developed a novel partially covered stent with a shaft diameter of 36 mm and a flare diameter of 40 mm.

Methods

From September 2008 to September 2010, 11 consecutive patients with postoperative leaks were treated with the novel large diameter stent (gastrectomy, n = 5; sleeve gastrectomy, n = 2; fundoplication after esophageal perforation, n = 2; Roux-en-Y gastric bypass, n = 1; esophageal resection, n = 1). Treatment with commercially available stents (shaft/flare: 23/28 mm and 24/30 mm) had been unsuccessful in three patients before treatment with the large diameter stent. Due to dislocation, the large diameter stent was anchored in four patients (2× intraoperatively with transmural sutures, 2× endoscopically with transnasally externalized threads).

Results

Treatment was successful in 11 of 11 patients. Stent placement and removal was easy and safe. The median residence time of the stent was 24 (range, 18–41) days. Stent dislocation occurred in four cases (36 %). It was treated by anchoring the stent. Mean follow-up was 25 (range, 14–40) months. No severe complication occurred during or after intervention and no patient was dysphagic.

Conclusions

Using the novel large diameter, partially covered stent to seal leaks in the upper GI tract is safe and effective. The large diameter of the stent does not seem to injure the wall of the upper GI tract. However, stent dislocation sometimes requires anchoring of the stent with sutures or transnasally externalized threads.     

Endoscopic stenting for benign upper gastrointestinal strictures and leaks

Background

Self-expandable metal stents (SEMS) and self-expandable plastic stents (SEPS) maybe used for the treatment of benign upper gastrointestinal (GI) leaks and strictures. This study reviewed our experience with stent insertions in patients with benign upper GI conditions.

Methods

Patients who underwent stent placement for benign upper GI strictures and leaks between March 2007 and April 2011 at a tertiary referral academic center were studied using an endoscopic database and electronic patient records. The technical success, complications, and clinical improvement after stent removal were compared according to type of stent. The outcomes measured were clinical response, adverse events, and predictors of stent migration.

Results

Thirty-eight patients (50 % male, mean age = 54 years, range = 12–82) underwent 121 endoscopic procedures. Twenty patients had stents placed for strictures, and 18 had stents placed for leaks. Stent placement was technically successful in all patients. The average duration of stent placement was 54 days (range = 18–118). Clinical improvement immediately after stent placement was seen in 29 of the 38 patients (76.3 %). Immediate post-procedure adverse events occurred in 8 patients. Late adverse events were seen in 18 patients. Evidence of stent migration occurred in 16 patients and was seen in 42 of the 118 successfully placed stents (35.5 %). Migration was more frequent with fully covered SEMS (p = 0.002). After stent removal, 27 patients were evaluable for long-term success (median follow-up time of 283 days, IQR 38–762). Resolution of strictures or leaks was seen in 11 patients (40.7 %). Predictors for long-term success included increasing age and if the stent did not cross the GE junction.

Conclusions

Placement of SEPS and SEMS for benign refractory strictures and fistulas has modest long-term clinical efficacy and is limited by a significant migration rate. Stent migration is common and frequent with fully covered SEMS compared to other types of stents, regardless of indication or location.     

A retrospective analysis of early and late outcome of biodegradable stent placement in the management of refractory anastomotic colorectal strictures

Background

Benign colorectal strictures are treated conventionally by endoscopic dilation. Experience using SEMS for benign colonic strictures is limited, and outcomes to date have been disappointing. Refractory colorectal strictures remain challenging to be treated with surgery. Polydioxanone-based stent are biodegradable (BD) stent CE approved for esophageal strictures. This study was designed to investigate retrospectively the safety and the efficacy of these stents for the management of strictures refractory to multiple sessions of dilation.

Methods

Patients with postsurgical benign strictures located within 20 cm from anal verge, refractory to mechanical or pneumatic dilation (at least 3 sessions) were included in this analysis. Clinical success was defined as the absence of occlusive symptoms and the ability to pass through the stricture with a regular size colonoscope. All patients were predilated before stent placement. Stents were released under fluoroscopic control. All patients were under stool softeners for 3 months. Follow-up was scheduled with endoscopic and fluoroscopic controls within 90 days from stent deployment and afterwards by telephone interview and/or ambulatory consultation.

Results

Eleven patients (7 males, mean age 62.3 ± 8.5 years) were included. Technical success was achieved in all the patients. Stent migration was observed in four patients within the first 2 weeks after stent placement. Stent migration was followed by recurrence of stricture and obstructive symptoms in all the cases. Among the seven patients who completed the process of stent biodegradation, five of them had complete resolution of the stricture and relief of symptoms. Two of 11 patients required surgical treatment during the follow-up period (mean 19.8 (range 42–15) months). The overall success rate of the BD stent was 45 %.

Conclusions

This retrospective analysis of a limited number of patients demonstrated that nondedicated esophageal BD stents are associated with high risk of migration and clinical success in less than 50 % of patients. Dedicated stents with large diameter and antimigration findings could potentially improve the outcome of patients with refractory benign colorectal strictures.     

Short-term stenting using fully covered self-expandable metal stents for treatment of refractory biliary leaks, postsphincterotomy bleeding, and perforations

Background

Fully covered self-expandable metal stents (FCSEMS) have been used as a rescue therapy for several benign biliary tract conditions (BBC). Long-term stent placement commonly occurs, and prolonged FCSEMS placement is associated with the majority of the complications reported. This study evaluated the duration of stenting and the efficacy and safety of temporary FCSEMS placement for three BBCs: refractory biliary leaks, postsphincterotomy bleeding, and perforations.

Methods

This was a retrospective case series with long-term follow-up of 25 patients who underwent FCSEMS placement for BBCs. This study included 17 patients with postcholecystectomy refractory biliary leaks who had previously undergone unsuccessful sphincterotomy and plastic stent placement, 4 patients with difficult-to-control postsphincterotomy bleeding, and 4 patients with a perforation following endoscopic sphincterotomy. Stents were removed according to clinical evidence of problem resolution. The review included stenting duration, safe FCSEMS removal, clinical efficacy, complications, and long-term outcomes. During the follow-up period, ERCP and cholangioscopy procedures were performed to exclude the possibility of bile duct lesion development.

Results

Complete resolution of the initial condition was achieved in all patients. Patients with biliary leaks had a median stent duration time of 16 days (range 7–28 days). Patients with bleeding had stents removed after a median time of 6 days (range 3–15 days). Patients with perforations had their stents removed after a median time of 29.5 days (range 21–30 days). There were no complications related to stenting.

Conclusions

Temporary placement of a FCSEMS for 30 days or less is an effective rescue therapy for refractory biliary leaks, difficult-to-control post-endoscopic sphincterotomy bleeding, and perforations. Duration of stenting should be different for each type of condition. Stents can be safely removed, and short-term stenting is associated with the absence of early and late complications.     

Gastrojejunostomy by pure natural orifice transluminal endoscopic surgery using a newly designed anastomosing metal stent in a porcine model

Background

The accepted palliative treatment for malignant gastric outlet obstruction (GOO) is surgical bypass or placement of self-expandable metal stents. We developed a safe and simple natural orifice transluminal endoscopic surgery (NOTES) technique for gastrojejunostomy using a fully covered, anastomosing metal stent in a porcine model.

Methods

Under general anesthesia, 11 pigs underwent gastrojejunostomy with a 4 cm length anastomosing metal stent. After gastrotomy formation using a needle knife, the jejunum was drawn into the stomach with alligator forceps. A jejunotomy was then performed in the gastric cavity, which was followed by deployment of an anastomosing metal stent under fluoroscopic guidance. Next, the first portion of the duodenum was resected by an endoscopic linear stapler via laparoscopy, thereby creating the model of GOO. Oral feeding was resumed 24 h after the procedure, and animals were euthanized at 1, 2, and 4 weeks after the operation.

Results

Side-to-side gastrojejunostomy was successfully completed through NOTES in 10/11 animals. Ten pigs stayed healthy until the planned sacrifice. The mean gastrojejunostomy procedure time was 41 min (range 15–94 min). By postmortem examination, anastomoses were still intact without intraperitoneal necrosis or adhesion. Histological examination revealed adequate submucosal apposition in all ten experimental pigs undergoing successful endoscopic gastrojejunostomy.

Conclusion

Creating a gastrojejunostomy by NOTES using an anastomosing metal stent seems to be a safe, feasible, durable, and reproducible method for GOO.     

Factors associated with 30-day readmission and long-term efficacy of enteral stent placement for malignancy

Background

Readmissions to the hospital within 30 days of discharge (30-day readmission rate) may impact stent use in palliative treatment of cancer.

Objective

Our objective was to investigate the incidence of readmission and factors predicting readmissions and long-term outcomes in patients with self-expanding metal stents (SEMS) placed for malignant obstruction.

Methods

Retrospective analysis of all patients who underwent placement of SEMS from 2007 to 2012 for malignant esophageal, gastroduodenal, and colonic obstruction. Incidence and variables associated with 30-day readmission and long-term outcomes were determined.

Results

A total of 191 patients underwent stent placement. The 30-day readmission rate was 17.3 % (N = 33). Readmissions were for stent-related complications in 7.3 % (N = 14) and non-stent-related complications in 9.9 % (N = 19). Stent placement was technically successful in 185 of 191 (96.9 %) and clinically successful in 170 of 191 (89.0 %) patients. On long-term follow-up, 32 (16.8 %) patients needed re-intervention. The mean stent patency was 142 days. Readmission within 30 days was independently associated with development of early complications (<7 days) following stent placement (odds ratio [OR] 5.90; 95 % confidence interval [CI] 2.04–17.1), while the stent location did not impact readmission risk. On Cox regression analysis, American Society of Anesthesiologists physical classification (OR 1.36; 95 % CI 1.02–1.87) and stent location in the esophagus (OR 1.82; 95 % CI 1.10–3.02) were independently associated with long-term mortality.

Conclusions

Early complications following stent placement increase the risk of 30-day readmission. SEMS is efficacious long-term for palliation of malignant gastrointestinal obstruction.     

Fully Covered Self-Expanding Metal Stents Are Effective For Benign Esophagogastric Disruptions and Strictures

Purpose

Self-expanding fully covered metal stents (CSs) are ideal for use in benign esophagogastric disease. We reviewed our experience with CS to evaluate outcomes, to determine a role for CS in a standard treatment for benign esophageal conditions, and to compare our results with recently published studies.

Methods

We performed a retrospective chart review from 2005 to 2012.

Results

A total of 57 CSs were placed in 44 patients. Indications were stricture (11 patients), anastomotic leak (20), perforation (7), and tracheoesophageal fistulae (6). For GI tract disruptions, open repair or diversion was avoided in 31/33 patients (93.9 %) but required an associated drainage procedure in 22/33 (67 %) patients. Resolution does not depend on achieving radiological control with 6/26 (23 %) having evidence of a persistent leak. Benign strictures were dilated at a mean of 3.7 times prior to stenting. Adjunctive intra-mucosal steroid injections were used in 8/11 patients. Stents were removed at a mean of 33 days. At a mean of 283 days of follow-up, 6/11 (54.5 %) had symptom resolution. The most common complication was stent migration occurring in 17.5 % of patients overall.

Conclusion

Covered stents are an effective adjunct in the management of benign upper gastrointestinal tract fistulae, leaks, perforations and benign strictures.     

The use of biodegradable (SX-ELLA) oesophageal stents to treat dysphagia due to benign and malignant oesophageal disease

Background

Biodegradable (BD) oesophageal stents have been available commercially only since 2008 and previous published research is limited. Our aim was to review the use of BD stents to treat dysphagia in benign or malignant oesophageal strictures.

Methods

Patients were identified from a prospective interventional radiological database. BD stents were inserted radiologically under fluoroscopic control.

Results

Between July 2008 and February 2011, 25 attempts at placing SX-ELLA biodegradable oesophageal stents were made in 17 males and five females, with a median age of 69 (range = 54–80) years. Two patients required more than one BD stent. Indications were benign strictures (n = 7) and oesophageal cancer (n = 17). One attempt was unsuccessful for a technical success rate of 96% with no immediate complications. Clinical success rate was 76%. Median dysphagia score before stent insertion was 3 (range = 2–4) compared to 2 (range = 0–3) after stent insertion (p = 0.0001).

Conclusion

BD stents provide good dysphagia relief for the life time of the stent. They may help avoid the use of feeding tubes in patients having radical chemoradiotherapy or awaiting oesophagectomy. They do not require removal or interfere with radiotherapy planning via imaging. However, the reintervention rate is high after the stent dissolves.     

Long-term efficacy of modified retrievable stents for treatment of achalasia cardia

Aim

To investigate the efficacy, safety and optimal duration of placement of modified retrievable metal stents for treatment of achalasia cardia.

Methods

Patients were randomly divided into groups A (N = 26, modified stents for 3 days), B (N = 26, modified stents for 2 days), C (N = 24, balloon dilation), and D (N = 25, regular stents for 2 days). Clinical symptom scores were recorded at baseline, 6 months, and during long-term follow-up.

Results

Seventy-seven patients with achalasia underwent stent placement (100 % success rate of implantation and extraction, no perforation). No stent migration or drop-off occurred in groups A and B. In group D, stent drop-off and migration was observed in 2 and 1 patients, respectively. Two patients in group C sustained esophageal perforation. Patients in the modified stent (A and B), balloon dilated (C) and regular stents (D) groups experienced significant improvement in dysphagia at 6 months, with recurrence in 1.92, 8.33 and 28 %, respectively. The clinical symptom score in the modified stent groups was significantly lower than that in the balloon dilated group (P = 0.01). During long-term follow-up, the symptom scores in modified stent groups were significantly lower than that in the balloon dilated (P < 0.01) and regular stent (P < 0.01) groups.

Conclusion

Modified retrievable metal stents required an optimal placement duration of 2 days were safe with no incidence of migration or drop-off and had a lower recurrence of symptoms.

     

Removable and repositionable covered metal self-expandable stents for leaks after upper gastrointestinal surgery: experiences in a tertiary referral hospital

Background

Anastomotic leakages are severe complications of upper gastrointestinal surgery with serious morbidity and mortality. Until recently, only abscess drainage was possible. Since 2007, removable and repositionable covered metal self-expandable stents (RReCoMSeS) have been used in our hospital to cover leaks.

Methods

Patients with postsurgical gastrointestinal leaks treated with RReCoMSeS between January 2007 and March 2010 were retrospectively evaluated and described.

Results

Twenty-six patients were treated with RReCoMSeS (totally covered Choo/Hanaro and partially covered Endoflex stents). Included patients had anastomotic leaks after esophagectomy (15) and bariatric surgery (11). Overall successful sealing of the leak occurred in 81 % (including multiple procedures). In total 33 RReCoMSeS were used (mean 1.3 stents and 1.7 procedures per patient). Twenty-one of 33 RReCoMSeS succeeded in sealing the leak (64 %). Migration occurred in 24 % RReCoMSeS, and 9 % disintegrated. One stent (3 %) caused a perforation.

Conclusions

RReCoMSeS are a safe alternative for treating postsurgical leaks in the upper gastrointestinal tract. In 81 % of patients and with 64 % of the inserted stents, leaks were sealed successfully, with few complications. Fewer stents per patient were needed thanks to their repositionability. Stent migration is a major problem.     

Covered self-expandable metal stents are more associated with complications in the management of malignant colorectal obstruction

Background

The use of self-expandable metal stents (SEMS) for the treatment of malignant colorectal obstruction is increasing. However, results of risk factors for its complications are inconsistent. This study aimed to examine the clinical effectiveness of the procedure as well as the complications and risk factors associated with the complications.

Methods

Medical records of patients with malignant colorectal obstruction who underwent endoscopic placement of covered or uncovered SEMS were reviewed retrospectively. The procedure was performed by two endoscopists with experience in pancreatobiliary endoscopy.

Results

A total of 152 patients were included (102 men; mean age, 70 ± 12.5 years). The procedure was performed for palliative management in 83 patients and performed as a bridge to surgery in 69 patients. There were 111 uncovered stents and 41 covered stents. The technical success rate was 100 % and the clinical success rate 94.1 %. Overall complications were observed in 49 patients (32.2 %) during the follow-up period (median, 98 days; interquartile range, 19–302 days). Obstruction (17.1 %), migration (7.9 %), perforation (5.2 %), bleeding (1.3 %), and tenesmus (0.7 %) were the causes of the complications. Stage IV disease, carcinomatosis peritonei, complete obstruction of the colon, palliative intention, and covered stents increased the complications based on the univariate analysis. Multivariate analysis revealed that complete obstruction of the colon and covered stents were significantly independent risk factors for complications. In the palliative group, Kaplan–Meier analysis showed significantly shorter median duration to the onset of complications in the covered stent group than in the uncovered stent group.

Conclusions

Although SEMS in patients with malignant colorectal obstruction is effective both as palliative therapy and as a bridge to surgery, one-third of patients experienced complications. Severity of obstruction and stent type can influence outcomes.     

Endoscopic therapy for esophageal perforation or anastomotic leak with a self-expandable metallic stent

Background

Leaks of the esophagus are associated with a high mortality rate and need to be treated as soon as possible. Therapeutic options are surgical repair or resection or conservative management with cessation of oral intake and antibiotic therapy. We evaluated an alternative approach that uses self-expandable metallic stents (SEMS).

Methods

Between 2002 and 2007, 31 consecutive patients with iatrogenic esophageal perforation (n = 9), intrathoracic anastomotic leak after esophagectomy (n = 16), spontaneous tumor perforation (n = 5), and esophageal ischemia (n = 1) were treated at our institution. All were treated with endoscopic placement of a covered SEMS. Stent removal was performed 4 to 6 weeks after implantation. To exclude continuous esophageal leak after SEMS placement, radiologic examination was performed after stent implantation and removal.

Results

SEMS placement was successful in all patients and a postinterventional esophagogram demonstrated full coverage of the leak in 29 patients (92%). In two patients, complete sealing could not be achieved and they were referred to surgical repair. Stent migration was seen in only one patient (3%). After removal, a second stent with larger diameter was placed and no further complication occurred. Two patients died: one due to myocardial infarction and one due to progressive ischemia of the esophagus and small bowl as a consequence of vascular occlusion. Stent removal was performed within 6 weeks, and all patients had radiologic and endoscopic evidence of esophageal healing.

Conclusions

Implantation of covered SEMS in patients with esophageal leak or perforation is a safe and feasible alternative to operative treatment and can lower the interventional morbidity rate.     

Role of endoscopic stents and selective minimal access drainage in oesophageal leaks: feasibility and outcome

Background

Leaks following oesophageal surgery are considered to be amongst the most dreaded complications and contributory to postoperative mortality. Controversies still exist regarding the best option for the management of oesophageal leaks due to lack of standardized treatment protocols. This study was designed to analyse the feasibility outcome and complications associated with placement of removable, fully covered, self-expanding metallic stents for oesophageal leaks with concomitant minimally invasive drainage when appropriate.

Methods

The study group included 32 patients from a prospectively maintained database of oesophageal leaks, with the majority being anastomotic leaks after minimally invasive oesophagectomy (n = 28), followed by laparoscopic cardiomyotomy (n = 3) and extended total gastrectomy (n = 1). The procedures took place between March 2007 and April 2013.

Results

Most patients had an intrathoracic leak (n = 22), with a mean time to detection of the leak following surgery of 7.50 days (SD = 2.23). Subsequent to endoscopic stenting, enteral feeding via a nasojejunal tube was started on the second day and oral feeding was delayed until the 14th day (n = 31). Six patients underwent thoracoscopic (n = 5) or laparoscopic drainage (n = 1) along with stenting for significant mediastinal and intra-abdominal contamination. The stent migration rate of our study was 8.54 %. The overall success in terms of preventing mortality was 96 %.

Conclusion

Endoscopic stenting should be considered a primary option for managing oesophageal leaks. Delayed oral intake may reduce the incidence of stent migration. Larger stents (bariatric or colorectal stents) serve as a useful option in case of migrated stents. Combined minimally invasive procedures can be safely adapted in appropriate clinical circumstances and may contribute to better outcomes.     

Partially covered esophageal stents cause bowel injury when used to treat complications of bariatric surgery

Background

We hypothesized that an esophageal nitinol stent that is mainly silicone-covered but partially uncovered may allow tissue ingrowth and decrease the migration rate seen with fully covered stents and still allow safe stent removal. The aim of this study was to evaluate the first human results of using partially covered stents for anastomotic complications of bariatric surgery.

Methods

This was a retrospective evaluation of all patients with staple-line complications after bariatric surgery who received a partly covered stent at a single tertiary-care bariatric center. The stents varied in length from 10 to 15 cm and in diameter from 18 to 23 mm.

Results

From April 2009 to April 2010, eight patients received partially covered stents on 14 separate occasions. The indications were gastrojejunal stricture in four, acute leak in two, acute leak followed by a later stricture in one, and a perforated anastomotic ulcer in one patient. Single stents were placed in 12 sessions and two overlapping stents in two sessions. At the time of stent deployment, one patient had the uncovered proximal end of the stent in the stomach, with all others in the distal esophagus. Immediate symptom improvement occurred in 12/14 stent placements. Oral nutrition was initiated for 10/14 stent treatments within 48 h. Stents were removed after 25 ± 10 days. Minor stent displacement occurred with 9/13 stents, with the proximal end of the stent moving into the stomach, though the site of pathology remained covered. The stents were difficult to remove when tissue ingrowth was present. One patient required laparoscopic removal and one required two endoscopy sessions for removal. At the time of removal of ten stents, where the proximal end was found in the stomach, four had gastric ulceration, three had gastric mucosa replaced by granulation tissue, and three had normal gastric mucosa. In four cases where the proximal portion of the stent stayed in the esophagus, the esophageal deployment zone had abnormalities: three with granulation tissue and one with denuding of the esophageal mucosa. The distal uncovered portion of the stent in the Roux limb never became embedded in the mucosa and caused minimal injury.

Conclusions

A partially covered stent was successful in keeping the site of the pathology covered and provided rapid symptom improvement and oral nutrition in most patients. The proximal end of the stent generally moved from the esophagus to the stomach, probably due to esophageal peristalsis. The proximal uncovered portion of the stent causes significant bowel mucosal injury and sometimes becomes embedded in the esophagus or the stomach, making removal difficult. We no longer use partially covered stents.     

Fully covered removable nitinol self-expandable metal stents (SEMS) in malignant strictures of the esophagus: a multicenter analysis

Background

Fully covered esophageal self-expandable metallic stents (SEMS) often are used for palliation of malignant dysphagia. However, experience and data on these stents are still limited. The purpose of this multicenter study was to evaluate the efficacy and safety of fully covered nitinol SEMS in patients with malignant dysphagia.

Methods

37 patients underwent placement of a SEMS during a 3?year period. Five patients underwent SEMS placement as a bridge to surgery: one for tracheoesophageal fistula in the setting of squamous cell carcinoma of the esophagus, one for perforation in setting of esophageal adenocarcinoma, 27 for unresectable esophageal cancer (16 adenocarcinoma, 11 squamous cell carcinoma), two for lung cancer, and one for breast-cancer-related esophageal strictures.

Results

SEMS placement was successful in all 37 patients. Immediate complications after stent deployment included chest pain (n?=?6), severe heartburn (n?=?1), and upper gastrointestinal bleeding requiring SEMS revision (n?=?1). Dysphagia scores improved significantly from 3.2?±?0.4 before stent placement to 1.4?±?1.0 at 1?month (P?P?P?=?0.0018) at 6?months. The stent was removed in 11 patients (30%) for the following indications: resolution of stricture (n?=?3), stent malfunction (n?=?5), and stent migration (n?=?3). After stent removal, three patients were restented, three underwent dilation, and two underwent PEG placement. Mean survival for the 37 patients after stent placement was 146.3?±?143.6 (range, 13–680) days.

Conclusions

Our study suggests that fully covered SEMS placement improve dysphagia scores in patients with malignant strictures, particularly in the unresectable population. Further technical improvements in design to minimize long-term malfunction and migration are required.     

A novel animal model of gastrointestinal obstruction for the development of stent

Background

The need for newer gastrointestinal (GI) stents has been continuously raised. Newly developed stents are generally tested for physical properties in vitro and directly introduced to clinical practice because there is no reliable animal model of GI obstruction. The aim of this study was to establish an animal model both that can represent obstruction of the GI tract and be used to develop new stents.

Material and methods

Surgical obstruction of the descending colon by wrapping with a nonabsorbable synthetic mesh and rubber bands was made in 17 healthy mongrel dogs. Four days later, a covered self-expanding metallic stent was placed for the obstructed segment in each dog under fluoroscopic guidance. Patency and migration of the inserted stents were evaluated clinically on a daily basis and fluoroscopically on a weekly basis. After sacrifice of the dogs, the degree and extent of residual colonic obstruction were assessed fluoroscopically. The specimen of the colonic obstructed segment was examined microscopically.

Results

In all 17 mongrel dogs, segmental obstruction in the descending colon was successfully created and confirmed with fluoroscopic examination using a contrast medium. The percentage of luminal narrowing ranged from 99%–100%. Stent placement was technically successful in all 17 dogs. During the follow-up period, stent migration occurred in 12 dogs and indwelling time of a stent ranged from 0–95 d (mean 29.2 ± 38.8 d). On postmortem pathologic examination, it was found that fibrosis had newly formed outside the colonic longitudinal muscle layer in all dogs.

Conclusions

Our canine colonic obstruction model is the first animal model that can be feasible for developing a new design of stent and provide in vivo data on complications, particularly stent migration.     

Pancreatic duct stenting for the duration of ERCP only does not prevent pancreatitis after accidental pancreatic duct cannulation: a prospective randomized trial

Background

Pancreatic duct stent placement during endoscopic retrograde cholangiopancreatography (ERCP) has been recommended in patients at risk for post-ERCP pancreatitis. However, the optimal duration of stent placement remains an open question. Our aim was to compare the efficacy of pancreatic stenting for the duration of ERCP only with spontaneous dislodgment/deferred endoscopic removal in preventing post-ERCP pancreatitis after accidental wire-guided pancreatic duct cannulation.

Methods

All patients in whom accidental wire-guided pancreatic duct cannulation had occurred during ERCP underwent immediate 5-Fr unflanged pigtail pancreatic duct stenting before attempting any other endoscopic maneuver. At the end of the ERCP, patients were randomly assigned to immediate stent removal (group A) or to leaving the stent in place (group B). Assessment of post-ERCP pancreatitis was blind.

Results

Post-ERCP pancreatitis occurred in 6/21 (29 %) patients in group A and in 0/19 patients in group B (P = 0.021); the two groups were well matched for their baseline characteristics. Post-ERCP pancreatitis was mild in two patients, moderate in two patients, and severe in two patients. Stents dislodged spontaneously in 14/19 (74 %) patients within 24–96 h; uneventful endoscopic removal was carried out after 96 h in 5 cases. Proximal stent migration did not occur in any case.

Conclusions

Pancreatic duct stent placement for the duration of ERCP only does not prevent post-ERCP pancreatitis. Pancreatic stents should be left in place until spontaneous dislodgment occurs or endoscopic removal is deemed timely. 5-Fr unflanged pigtail stents remain in place for a period sufficient to prevent post-ERCP pancreatitis and do not migrate proximally.     

Comparison of uncovered and covered stents for the treatment of malignant duodenal obstruction caused by pancreaticobiliary cancer

Background

Few clinical studies to date have compared different types of self-expandable metallic stents (SEMS) and their outcomes in patients with pure duodenal obstruction caused by pancreaticobiliary cancer. The aim of this study was to compare the clinical effectiveness and side effects of uncovered and covered SEMS for the palliation of duodenal obstruction caused by pancreaticobiliary cancer.

Methods

We retrospectively analyzed all patients with pancreaticobiliary cancer who underwent upper endoscopy with SEMS placement for malignant duodenal obstruction at the National Cancer Center of Korea between April 2003 and December 2010. The technical and clinical success rates of the procedure, complications, and durations of stent patency and overall survival were evaluated.

Results

We identified 70 patients with a mean age of 51.2 years (range = 39–81 years); of these, 46 (65.7 %) had pancreatic cancer, 9 (12.9 %) had bile duct cancer, 11 (15.7 %) had gallbladder cancer, and 4 (5.7 %) had cancer of the ampulla of Vater. Twenty-four patients (34.3 %) received covered SEMSs and 46 (65.7 %) received uncovered SEMSs. Technical and clinical success rates were similar for the covered and uncovered stent groups. The complication rate was higher in the covered than in the uncovered group (62.5 vs. 34.8 %, P = 0.025), due primarily to a significantly higher stent migration rate (20.8 vs. 0 %, P = 0.004). Perforation as a late complication occurred in four patients, two in each group (8.3 vs. 4.3 %, P = 0.425). Stent patency tended to be shorter for covered than for uncovered duodenal stents (13.7 ± 8.6 weeks vs. not reached, P = 0.069).

Conclusions

The use of uncovered stents may be a preferred option for duodenal obstruction secondary to pancreaticobiliary malignancies, since they were effective in preventing stent migration and tended to have longer patency than covered stents. Careful attention should be paid to signs and symptoms of perforation during follow-up.     

Covered stents in cervical anastomoses following esophagectomy

Introduction

Anastomotic complications after esophagectomy are relatively frequent. The off-label use of self-expanding covered metal stents has been shown to be an effective initial treatment for leaks, but there is a paucity of literature regarding their use in cervical esophagogastric anastomoses. We reviewed our outcomes with anastomotic stenting after esophagectomy with cervical esophagogastric reconstruction.

Methods

All stents placed across cervical anastomoses following esophagectomy from 2004 to 2014 were retrospectively reviewed. Indications for surgery and stent placement were collected. For patients with serial stents, each stent event was evaluated separately and as part of its series. Success was defined as resolution of indicated anastomotic problem for at least 90 days. Complications were defined as development of stent-related problems.

Results

Twenty-three patients had a total of 63 stents placed (16 % prophylactic, 38 % leak, 46 % stricture). Sixty percent of patients had successful resolution of their initial anastomotic problem; 67 % required more than one stent. Strictures and leaks healed in 27 and 70 % of patients, respectively, at a median of 55.5 days. Stent-related complications occurred in 78 % of patients. Complications (per stent event) included 62 % migration, 11 % clinically significant tissue overgrowth, 8 % minor erosion (ulcers), and 8 % major erosion. Stents placed for stricture were more likely to result in complications, especially migration (76.7 vs. 48.5 %, p = 0.02). Preoperative chemoradiation was a significant risk factor for erosion (22.5 vs. 4.3 %, p = 0.05), but not for overall complications. Patients with major erosions had longer stent duration compared to those without (92 vs. 36 days, p = 0.14).

Discussion

Although stents are effective at controlling post-esophagectomy anastomotic leaks, they are not effective for treating strictures. Stents have high complication rates, but most are minor. Chemoradiation is a risk factor for stent erosion. Caution should be used when stent duration exceeds 2–3 months due to the risk of erosion.

     

Self-expandable Metallic Stents in Patients with Stage IV Obstructing Colorectal Cancer

Background

The aim of the present study was to analyze the results of our experience with elective placement of self-expandable metallic stents (SEMS) in patients with stage IV obstructing colorectal cancer. A systematic review of the literature was also carried out to analyze the factors influencing the results of SEMS placement and to determine if there has been any improvement in the more recent period.

Materials and methods

The results of a personal series of 100 patients were analyzed. There was no case of mortality or major morbidity. The systematic review included 27 articles published from April 2007 to December 2011.

Results

In our experience the technical success rate was 96 % and the clinical success rate was 92 %. During the follow-up period a repeat colonoscopy was needed in 31 % of the patients for recurrent symptoms of obstruction due to fecal impaction (19 %), tumor growth (8 %), or stent dislodgment (4 %). Review of the literature showed similar results, with a significant improvement in the reports of the last 6 years; procedures performed on an emergency basis had poorer results.

Conclusions

Self-expandable metallic stent placement offers a valid alternative to surgery in patients with obstructing stage IV colorectal cancer, but careful follow-up is required.