Comparison of uncovered stent with covered stent for treatment of malignant colorectal obstruction

Intestinal stents: Structure, functionalization and advanced engineering innovation

Intestinal stents are a palliative treatment option that solves many shortcomings of traditional surgeries for cancer-induced intestinal obstructions. The present review provides an overview of the incidence, clinical manifestations and limitations in the treatment of intestinal cancers. The paper also discusses material property requirements, indications, complications and the future of stent-assisted therapy. The advantages and disadvantages of different materials and processing techniques for intestinal stents are reviewed along with new stent treatment combinations for colorectal cancer. Challenges that require further cooperative studies are also detailed. The future development of intestinal stents will depend on innovation in material designs as well as the utilization of multi-functional strategies and innovative engineering solutions.

Short-Term Outcomes of Colorectal Stenting Using a Low Axial Force Self-Expandable Metal Stent for Malignant Colorectal Obstruction: A Japanese Multicenter Prospective Study

(1) Background: Endoscopic colorectal stenting with high technical success and safety is essential in discussing the oncological outcomes for the management of malignant colorectal obstruction. Mechanical properties of self-expandable metal stents are usually considered to affect clinical outcomes. (2) Methods: A multicenter, prospective study was conducted in Japan. A self-expandable metal stent with low axial force was inserted endoscopically. The primary endpoint was clinical success, defined as the resolution of symptoms and radiological findings within 24 h. Secondary endpoints were technical success and adverse events. Short-term outcomes of 7 days were evaluated in this study. (3) Results: Two hundred and five consecutive patients were enrolled. Three patients were excluded, and the remaining 202 patients were evaluated. The technical and clinical success rates were 97.5% and 96.0%, respectively. Major stent-related adverse events included stent migration (1.0%), insufficient stent expansion (0.5%), and stent occlusion (0.5%). No colonic perforation was observed. There were two fatal cases (1%) which were not related to stent placement. (4) Conclusions: The placement of self-expandable metal stents with low axial force is safe with no perforation and showed high technical and clinical success rates in short-term outcomes for the management of malignant colorectal obstruction.

A novel animal model of colonic stenosis to aid the development of new stents for colon strictures

BACKGROUND

The incidence of colonic stenosis, primarily caused by colon cancer and Crohn's disease, is increasing each year. The development of safer stents for colonic stenosis is required because perforation associated with cancer stent placement worsens the prognosis and stent placement for anastomotic stenosis due to Crohn's disease or colectomy is not first choice due to the high migration rate. The wall of the large intestine where the stent is inserted receives the complex forces from the peristaltic movement of the large intestine and stool in addition to the reaction tension of the stent, causing perforation and migration. Animal models may help develop new and safe stents, but no animal model closely reproduces the condition of human colonic stenosis. Herein, we present a novel animal model of colonic stenosis, which closely replicates the human colonic size.

METHODS

The artificial colonic stenosis model was developed by wrapping the porcine colon with a silicone sheet after laparotomy. The usefulness of the model was evaluated by investigating the availability of endoscopic stent placement, morphological maintenance of colonic stenosis, adverse effects on pigs, and modeling time. The first three and the last three modeling times were analyzed using Student's t-test.

RESULTS

Endoscopic stent placement was performed in all cases without intraoperative complications. There were no postoperative model complications or deaths. Adhesions to the surrounding tissue in the abdominal cavity of the artificial colon stenosis were slight. The morphology of the isolated artificial stenoses was completely maintained, and no necrosis or perforation was observed.

CONCLUSIONS

We developed a novel and feasible animal model of colonic stenosis using pigs. We believe that this animal model will be useful for developing a safer stent for obstruction caused by benign diseases and colon cancer.

Definition of large bowel obstruction by primary colorectal cancer: A systematic review

AIM

Controversies on therapeutic strategy for large bowel obstruction by primary colorectal cancer mainly concern acute conditions, being essentially different from subacute obstruction. Clearly defining acute obstruction is important for design and interpretation of studies as well as for guidelines and daily practice. This systematic review aimed to evaluate definitions of obstruction by colorectal cancer in prospective studies.

METHOD

A systematic search was performed in PubMed, Embase and the Cochrane Library. Eligibility criteria included randomized or prospective observational design, publication between 2000 and 2019, and the inclusion of patients with an obstruction caused by colorectal cancer. Provided definitions of obstruction were extracted with assessment of common elements.

RESULTS

A total of 16 randomized controlled trials (RCTs) and 99 prospective observational studies were included. Obstruction was specified as acute in 28 studies, complete/emergency in five, (sub)acute or similar terms in four and unspecified in 78. Five of 16 RCTs (31%) and 37 of 99 cohort studies (37%) provided a definition. The definitions included any combination of clinical symptoms, physical signs, endoscopic features and radiological imaging findings in 25 studies. The definition was only based on clinical symptoms in 11 and radiological imaging in six studies. Definitions included a radiological component in 100% of evaluable RCTs (5/5) vs. 54% of prospective observational studies (20/37, P = 0.07).

CONCLUSION

In this systematic review, the majority of prospective studies did not define obstruction by colorectal cancer and its urgency, whereas provided definitions varied hugely. Radiological confirmation seems to be an essential component in defining acute obstruction.

The Association of Coloproctology of Great Britain and Ireland consensus guidelines in emergency colorectal surgery

AIM

There is a requirement for an expansive and up to date review of the management of emergency colorectal conditions seen in adults. The primary objective is to provide detailed evidence-based guidelines for the target audience of general and colorectal surgeons who are responsible for an adult population and who practise in Great Britain and Ireland.

METHODS

Surgeons who are elected members of the Association of Coloproctology of Great Britain and Ireland Emergency Surgery Subcommittee were invited to contribute various sections to the guidelines. They were directed to produce a pathology-based document using literature searches that were systematic, comprehensible, transparent and reproducible. Levels of evidence were graded. Each author was asked to provide a set of recommendations which were evidence-based and unambiguous. These recommendations were submitted to the whole guideline group and scored. They were then refined and submitted to a second vote. Only those that achieved >80% consensus at level 5 (strongly agree) or level 4 (agree) after two votes were included in the guidelines.

RESULTS

All aspects of care (excluding abdominal trauma) for emergency colorectal conditions have been included along with 122 recommendations for management.

CONCLUSION

These guidelines provide an up to date and evidence-based summary of the current surgical knowledge in the management of emergency colorectal conditions and should serve as practical text for clinicians managing colorectal conditions in the emergency setting.

Comparing the mechanical properties of a self-expandable metallic stent for colorectal obstruction: Proposed measurement method of axial force using a new measurement machine

OBJECTIVES

Colorectal stenting is widely performed using self-expandable metallic stents (SEMSs), but the mechanical properties have not been evaluated. Therefore, we conducted an in vitro study to evaluate the mechanical properties of colorectal SEMSs.

METHODS

Eighteen individual types and sizes of uncovered SEMSs were evaluated for their mechanical properties. Radial force was measured using a measurement machine. Axial force (AF) was measured by two methods: a conventional manual method and a new method using a measurement machine. The correlation of these two methods was evaluated. We also proposed an "AF zero border" that was defined as the angle at which the torque force disappeared.

RESULTS

Radial force versus diameter curves and AF versus angle curves were influenced by the structure and the size of each stent. There was excellent correlation of AFs measured by the new and conventional manual method (y = 21.434x, R = 0.881, P < 0.0001). Colorectal SEMSs could be categorized into five subgroups according to the mechanical properties. Most hook-wired SEMSs had the AF of zero border.

CONCLUSIONS

This is the first report to evaluate the mechanical properties of colorectal SEMSs, and these data may provide useful information for the clinical use and development of colorectal SEMS. Furthermore, the new measurement machine might standardize the measuring method of AF.

Comparison of different types of covered self-expandable metal stents for malignant colorectal obstruction

BACKGROUND

Stent migration is one of the main drawbacks of covered self-expandable metal stent (SEMSs), occurring in up to 40% of malignant colorectal obstruction management cases. Various types of covered SEMSs have been developed to reduce this risk. We aimed to compare the effectiveness and complication rates of the flare-type covered SEMS (Flare) with those of the double-layered covered SEMS (ComVi).

METHODS

We performed a prospective, randomized study in four tertiary referral centers between July 2016 and April 2018. Patients with malignant colorectal obstruction were eligible for the study. The primary outcome was migration rate as observed within the first month. Rates of technical success, clinical success, and complications within the first month were also assessed.

RESULTS

A total of 60 patients were included (mean age, 70.5 ± 12.5 years; male, 31 [51.7%]). Flare and ComVi stents were applied in 30 patients each. The Flare and ComVi groups showed comparable technical success rates (90% [27/30] vs. 96.7% [29/30], p = 0.605) and clinical success rates (85.2% [23/27] vs. 75.9% [22/29], p = 0.589). Migration occurred in three (11.1%) and four (13.8%) cases in the Flare and ComVi groups, respectively, without significant difference (p = 0.99), and the risk of other complications, including perforation and re-obstruction, did not differ between the two groups.

CONCLUSIONS

Our study indicates that both flare-shape and double-layered covered SEMSs are equally effective options for the management of malignant colorectal obstruction with low migration rates when compared with previously reported migration risk of covered SEMS.

Uncovered versus covered stent in management of large bowel obstruction due to colorectal malignancy: a systematic review and meta-analysis

PURPOSE

To compare outcomes of uncovered stent and covered stent in management of large bowel obstruction secondary to colorectal malignancy.

METHODS

We conducted a search of electronic databases identifying studies comparing outcomes of uncovered and covered stents in management of large bowel obstruction secondary to colorectal malignancy. The Cochrane risk-of-bias tool and the Newcastle-Ottawa scale were used to assess the included studies. Random or fixed effects modelling were applied as appropriate to calculate pooled outcome data.

RESULTS

One randomised controlled trial (RCT) and nine observational studies, enrolling 753 patients, were identified. Uncovered stent was associated with lower risks of complications (RR 0.57 95% CI 0.44-0.74, P < 0.0001), tumour overgrowth (RR 0.29 95% CI 0.09-0.93, P = 0.04), and stent migration (RR 0.29 95% CI 0.17-0.48, P < 0.00001); longer duration of patency (MD 18.47 95% CI 10.46-26.48, P < 0.00001); lower need for stent reinsertion (RR 0.38 95% CI 0.17-0.86, P = 0.02); and higher risk of tumour ingrowth (RR 4.53 95% CI 1.92-10.69, P = 0.0008). Rates of technical success (RR 1.02 95% CI 0.99-1.04, P = 0.21), clinical success (RR 1.03 95% CI 0.98-1.08, P = 0.32), perforation (RD 0.01 95% CI - 0.03-0.02, P = 0.65), bleeding (RD 0.00 95% CI - 0.03-0.03, P = 0.98), stool impaction (RR 0.56 95% CI 0.12-2.04, P = 0.38) and stent obstruction (RR 2.23 95% CI 0.94-5.34, P = 0.97) were similar.

CONCLUSIONS

Our results suggest that uncovered stents are superior as indicated by fewer complications, lower rates of stent migration, longer duration of patency and a reduced need for stent reinsertion. The best available evidence is mainly derived from non-randomised studies; there is a need for more RCTs.

Predictors of outcome for endoscopic colorectal stenting: a decade experience

PURPOSE

Endoscopic stenting is used with increasing frequency to treat colorectal conditions. Little is known about what influences outcome. This study aimed to determine the impact of various factors on the short- and long-term results of colorectal stenting.

METHODS

A retrospective review was conducted of all endoscopic stenting procedures performed by a colorectal surgeon at a tertiary referral institution between 2003 and 2013. Main outcome measures included technical success, clinical success, complications, and predictors of outcome.

RESULTS

Of the stent procedures, 183 were performed in 165 patients. The majority of patients (90 %) presented with a malignant obstruction (intrinsic colonic vs. extrinsic non-colonic). Carcinomatosis was present in 22 % of patients with malignancy, and it was associated with lower technical success compared to non-carcinomatosis (adjusted odds ratio [AOR] 0.2 [95 % confidence interval (CI) 0.1-0.8]; p = 0.021). Colonic malignancy was associated with higher clinical success compared to non-colonic malignancy (AOR 3.8 [95 % CI 1.4-10.3]; p = 0.009). Carcinomatosis increased the risk of complications compared to non-carcinomatosis (AOR 3.2 [95 % CI 1.0-10.0]; p = 0.049). The risk of complication was higher when a stent was deployed in the rectum compared to the colon (AOR 4.1 [95 % CI 1.5-11.7]; p = 0.008). The use of a covered stent was associated with higher complication rate compared to a non-covered stent (AOR 13.6 [95 % CI 2.6-71.2]; p = 0.002). Balloon dilation was associated with an increased risk of complications (AOR 4.6 [95 % CI 1.3-16.2]; p = 0.017).

CONCLUSIONS

Carcinomatosis was associated with lower technical success rate. Clinical success was higher in patients with a primary colonic malignancy. The use of a covered stent, balloon dilation of stricture, lesions in the rectum, and carcinomatosis were associated with higher risk for complications.

Surgical palliation of gastric outlet obstruction in advanced malignancy

Gastric outlet obstruction (GOO) is a common problem associated with advanced malignancies of the upper gastrointestinal tract. Palliative treatment of patients’ symptoms who present with GOO is an important aspect of their care. Surgical palliation of malignancy is defined as a procedure performed with the intention of relieving symptoms caused by an advanced malignancy or improving quality of life. Palliative treatment for GOO includes operative (open and laparoscopic gastrojejunostomy) and non-operative (endoscopic stenting) options. The performance status and medical condition of the patient, the extent of the cancer, the patients prognosis, the availability of a curative procedure, the natural history of symptoms of the disease (primary and secondary), the durability of the procedure, and the quality of life and life expectancy of the patient should always be considered when choosing treatment for any patient with advanced malignancy. Gastrojejunostomy appears to be associated with better long term symptom relief while stenting appears to be associated with lower immediate procedure related morbidity.

Technical and Clinical Outcomes Following Colonic Stenting: A Seven-Year Analysis of 268 Procedures

AIMS

To assess the factors contributing to the technical and clinical success of colorectal stenting for large bowel obstruction.

METHODOLOGY

268 cases of colonic stenting for large bowel obstruction were performed in 249 patients of mean age of 72 years (28-98) between 2006 and 2013. The majority of strictures were due to malignant disease, 244/268 (91 %). Diverticular strictures accounted for 24/268 (9 %).

RESULTS

Overall technical success rate was 81 % (217/268), with a clinical success rate of 65 % (174/268). Duration of symptoms ranged from 0 to 180 days (mean 8 days). Technical success rate was seen to decrease with increasing symptom duration. For symptom duration of less than 1 week, technical success was 85.4 % (181/212) versus 69.6 % (39/56) for those with symptoms of greater than a week (p < 0.05). Clinical success rates fell from 71.3 % (107/150) to 59.3 % (70/118) (p < 0.05) when attempting to stent lesions of greater than 5 cm. There was also a significant reduction in clinical success when stenting lesions on a bend rather than a straight segment of colon 75.7 % (109/144) versus 59.7 % (74/124) (p < 0.05). A total of 20 (7.46 %) perforations were identified during the study. Stent migration occurred in 6.6 % of cases. In-stent stenosis occurred in 3.3 %. The overall 30-day all cause mortality rate was 9 %.

CONCLUSION

Lesion size, location and duration of obstructive symptoms are statistically significant determinants of patient outcome. These factors could be used to advise patient selection for colonic stenting or direct progression to surgical intervention.

Treatment of gastric outlet obstruction that results from unresectable gastric cancer: Current evidence

Malignant gastric outlet obstruction (GOO) is a common condition that results from locally advanced malignancies in the upper gastrointestinal tract, such as pancreatic, gastric, and other carcinomas. Two types of procedures for malignant GOO, namely, gastrojejunostomy (GJ) with laparotomy or a laparoscopic approach and endoscopic stenting (ES), are currently available. Although numerous previous reports have clarified the benefits and drawbacks of each procedure, whether GJ or ES should be used in patients with GOO that results from gastric cancer who may have a longer life expectancy than patients with other malignancies has not been determined. In this review, which focuses on gastric cancer-induced GOO, we analyzed the two systematic reviews and a meta-analysis that compared GJ and ES and outlined the current status of GOO treatment. We also provide an updated review that includes laparoscopic GJ. Various data from 13 studies in one review and 6 studies in another review were analyzed. Although the main results of the present review indicated that both GJ and ES were efficacious treatments in patients with GOO that resulted from gastric cancer, current evidence suggests that GJ may be the preferable procedure given its good performance status and improved prognosis in gastric cancer patients.

Self-Expanding Metallic Stents for the Management of Emergency Malignant Large Bowel Obstruction: a Systematic Review

OBJECTIVES

This paper evaluates the safety and effectiveness of self-expanding metallic stents (SEMS) for the management of emergency malignant colorectal obstruction in patients otherwise requiring multi-stage surgery. No systematic review has been conducted comparing SEMS to only multi-stage surgery.

METHODS

Bibliographic databases, including Cochrane, PubMed, EMBASE, and CINAHL, were searched in September 2011 and repeated in November 2013. A pre-determined protocol outlined the study inclusion and appraisal.

RESULTS

Forty articles were included, seven compared SEMS to multi-stage surgery. Included studies were of low to moderate quality. Bowel perforation was the most severe stent-related complication, while tumor- and stent-related events occurred most frequently. No significant differences in rates of obstruction relief were reported between treatments, and results regarding relative quality of life were inconclusive. SEMS recipients progressed to elective surgery sooner and required shorter post-procedural hospital stays, but commonly required re-intervention. SEMS provided enduring palliative relief of obstruction, with comparable survival longevity between treatments. Conclusion: SEMS placement is a viable alternative to multi-stage surgery, providing patients with benefits as a bridge-to-surgery and relief of obstruction in a palliative context, with minimal differences in clinical success and safety compared to multi-stage surgery.

Acute Treatment of Malignant Colorectal Occlusion: Real Life Practice

Introduction

Colorectal cancer presents itself as acute bowel occlusion in 10–40% of patients. There are two main therapeutic approaches: urgent surgery and endoluminal placement self-expandable metallic stents (SEMS).

Aims and Methods

This study intended to better clarify the risk/benefit ratio of the above-mentioned approaches. We conducted a retrospective longitudinal multicenter study, including 189 patients with acute malignant colorectal occlusion, diagnosed between January 2005 and March 2013.

Results

Globally (85 patients – 35 bridge-to-surgery and 50 palliative), SEMS's technical success was of 94%. Palliative SEMS had limited clinical success (60%) and were associated with 40% of complications. SEMS occlusion (19%) was the most frequent complication, followed by migration (9%) and bowel perforation (7%). Elective surgery after stenting was associated with a higher frequency of primary anastomosis (94% vs. 76%; p = 0.038), and a lower rate of colostomy (26% vs. 55%; p = 0.004) and overall mortality (31% vs. 57%; p = 0.02). However, no significant differences were identified concerning postoperative complications. Regarding palliative treatment, no difference was found in the complications rate and overall mortality between SEMS and decompressive colostomy/ileostomy. In this SEMS subgroup, we found a higher rate of reinterventions (40% vs. 5%; p = 0.004) and a longer hospital stay (14, nine vs. seven, three days; p = 0.004).

Conclusion

SEMS placement as a bridge-to-surgery should be considered in the acute treatment of colorectal malignant occlusion, since it displays advantages regarding primary anastomosis, colostomy rate and overall mortality. In contrast, in this study, palliative SEMS did not appear to present significant advantages when compared to decompressive colostomy.

Stents for colorectal obstruction: Past, present, and future

Since the development of uncovered self-expanding metal stents (SEMS) in the 1990s, endoscopic stents have evolved dramatically. Application of new materials and new designs has expanded the indications for enteral SEMS. At present, enteral stents are considered the first-line modality for palliative care, and numerous types of enteral stents are under development for extended clinical usage, beyond a merely palliative purpose. Herein, we will discuss the current status and the future development of lower enteral stents.

Role of self-expanding metal stents in patients with malignant colorectal obstruction: A systematic review and meta-analysis

AIM: To assess the safety and efficacy of self-expandable metal stents (SEMSs) for malignant colorectal obstruction.

METHODS: Data regarding technical success, clinical success, and procedure related complications were collected from included studies. DerSimonian-Laird random effects model was used to generate the overall outcome. Thirty international studies with a total of 2058 patients with malignant colorectal obstruction were included.

RESULTS: The technical and clinical success rates for SEMS placement were 94% (95%CI: 92-96) and 91% (95%CI: 88-93), respectively. Overall complication rate for SEMS was 23% (95%CI: 18-29). Stent migration 8% (95%CI: 6-10) and stent obstruction 8% (95%CI: 6-11) were the most common complications, followed by perforation 5% (95%CI: 4%-7%). Surgical or endoscopic re-interventions were needed in 14% (95%CI: 10-18) of patients. Endoscopic repeat stent placement was required in 8% (95%CI: 6-10), while surgical intervention was needed in 6% (95%CI: 4-8).

CONCLUSION: SEMS are effective when used as palliation or bridge to surgery for malignant colorectal obstruction with high technical and clinical success. About 14% of patients require repeat endoscopic or surgical intervention for stent failure or to manage stent related complications.

Clinical efficacy of endoscopic treatment for benign colorectal stricture: balloon dilatation versus stenting

BACKGROUND/AIMS

There has been a lack of research comparing balloon dilatation and self-expandable metal stent (SEMS) placement to determine which is better for long-term clinical outcomes in patients with benign colorectal strictures. We aimed to compare the clinical efficacy and complication rates of balloon dilatation and SEMS placement for benign colorectal strictures from a variety of causes.

METHODS

Between January 1999 and January 2012, a total of 43 consecutive patients who underwent endoscopic treatment for benign colorectal stricture (balloon only in 29 patients, SEMS only in seven patients, and both procedures in seven patients) were retrospectively reviewed.

RESULTS

Thirty-six patients underwent endoscopic balloon dilatation, representing 65 individual sessions, and 14 patients received a total of 17 SEMS placements. The initial clinical success rates were similar in both groups (balloon vs SEMS, 89.1% vs 87.5%). Although the reobstruction rates were similar in both groups (balloon vs SEMS, 54.4% vs. 57.1%), the duration of patency was significantly longer in the balloon dilatation group compared with the SEMS group (65.5±13.3 months vs. 2.0±0.6 months, p=0.031).

CONCLUSIONS

Endoscopic balloon dilatation is safe and effective as an initial treatment for benign colorectal stricture and as an alternative treatment for recurrent strictures.

Endoluminal occlusion devices: technology update

Endoluminal occlusion has been performed since the early beginning of interventional radiology. Over recent decades, major technological advances have improved the techniques used and different devices have been developed for changing conditions. Most of these occlusion devices have been implemented in the vascular territory. Early embolization materials included glass particles, hot contrast, paraffin, fibrin, and tissue fragments such as muscle fibers and blood clots; today, occlusion materials include metallic devices, particles, and liquid materials, which can be indicated for proximal or distal occlusion, high-flow and low-flow situations, and in large-caliber and small-caliber vessels, based on need. Technological progress has led to a decreased size of delivery catheters, and an increase in safety due to release systems that permit the withdrawing and replacement of embolization material. Furthermore, bioactive embolization materials have been developed to increase the efficacy of embolization or the biological effect of medication. Finally, materials have been modified for changing indications. Intravascular stents were initially developed to keep an artery open; however, by adding a covering membrane, these stents can be used to occlude the wall of a vessel or other endoluminal structures. This article gives an overview of the devices most utilized for occlusion of endoluminal structures, as well as their major purpose in the endovascular territory.

Short-term outcomes following the use of self-expanding metallic stents in acute malignant colonic obstruction--a single centre experience

BACKGROUND

Colonic self-expanding metallic stents (SEMS) may provide prompt relief of acute malignant colorectal obstruction (AMCO) and are increasingly used either palliatively or as a bridge to surgery (BTS) in patients in whom a definitive surgical approach is unsuitable. We evaluated short-term outcomes of malignant colorectal obstructive patients who underwent SEMS insertion in our institution over a 3-year period.

METHODS

A prospectively maintained database was reviewed to identify all patients who presented to our institution with AMCO between August 2010 and 2013 and who were treated with a SEMS either temporarily or permanently. Additional data was retrieved from chart reviews and operation notes.

RESULTS

Sixteen patients (12 males, 4 females) each had a single stent inserted during the study period, either palliatively (n = 11) or as a BTS (n = 5). The technical and clinical success rates were both 87.5% (14/16). The two unsuccessful stenting cases both had disseminated disease and required emergency surgery while five patients with curable disease proceeded to elective resections. There was no procedure-related mortality or stent-related perforations. The mean (standard deviation) length of stay post acute surgery was longer than elective surgery [45 ± 21.2 vs. 15.8 ± 4.0, days]. All patients in the BTS group were stoma-free post-operatively, while both patients who had emergency surgery ended up with permanent stomas. Finally, the stent complication rate was 6.2% (1/16), secondary to migration.

CONCLUSIONS

Although limited by a small sample size, the study shows that SEMS have favourable short-term outcomes. Further adequately powered trials are needed to confirm those findings.

Stenting for Emergency Colorectal Obstruction: An Analysis of 204 Patients in Relation to Predictors of Failure and Complications

Background and Aims:

Self-expanding metallic stents are increasingly used in the management of malignant and benign colorectal obstructions. We aimed to identify relevant predictive factors for stent failure and stent-related complications.

Material and Methods:

We conducted a retrospective single-center analysis of 204 consecutive patients who underwent emergency colorectal stenting procedures because of symptomatic bowel obstructions from 1996 to 2011 at the Sisters of Charity Hospital Linz, Austria.

Results:

A total of 204 patients (median age 74 years) with 36 (17.7%) benign and 168 (82.3%) malignant obstructions were included in the study. Technical success was achieved in 92.5% and clinical success in 86.8% of the cases. Major complications occurred in 2.9% and minor ones in 19.6%. Overall mortality during a median follow-up period of 4.3 years was 73% (149 patients). Relevant predictors of increased risk of complications were extracolonic obstruction (p = 0.001), complete obstruction (p = 0.066), and inflammatory bowel disease (p = 0.05). Stent localization at the splenic flexure, a stenosis of >8 cm in length, and the need for endoscopic guidance were associated with higher rates of technical and/or clinical stenting failure.

Conclusion:

Colorectal stenting is less invasive than other means of emergency treatment for large bowel obstruction; it is generally safe and effective in different types of colorectal obstruction. However, relevant rates of failure and complications were recorded and predictors could be determined.

Conformable covered versus uncovered self-expandable metallic stents for palliation of malignant gastroduodenal obstruction: a randomized prospective study

BACKGROUND

A conformable self-expandable metallic stent was developed to overcome the limitation of previous self-expandable metallic stents. The aim of this study was to evaluate outcomes after placement of conformable covered and uncovered self-expandable metallic stents for palliation of malignant gastroduodenal obstruction.

METHODS

A single-blind, randomized, parallel-group, prospective study were conducted in 4 medical centres between March 2009 and July 2012. 134 patients with unresectable malignant gastroduodenal obstruction were assigned to a covered double-layered (n=66) or uncovered unfixed-cell braided (n=68) stent placement group. Primary analysis was performed to compare re-intervention rates between two groups.

RESULTS

120 patients were analysed (59 in the covered group and 61 in the uncovered group). Overall rates of re-intervention were not significantly different between the two groups: 13/59 (22.0%) in the covered group vs. 13/61 (21.3%) in the uncovered group, p=0.999. Stent migration was more frequent in the covered group than in the uncovered group (p=0.003). The tumour ingrowth rate was higher in the uncovered group than in the covered group (p=0.016).

CONCLUSIONS

The rates of re-intervention did not significantly differ between the two stents. Conformable covered double-layered and uncovered unfixed-cell braided stents were associated with different patterns of stent malfunction.

Perforation in colorectal stenting: a meta-analysis and a search for risk factors

BACKGROUND

Recent studies suggest that there is a substantial risk of perforation after colorectal stent placement.

OBJECTIVE

To identify risk factors for perforation from colonic stenting.

DESIGN

A meta-analysis of 86 studies published between 2005 and 2011.

SETTING

Multicenter review.

PATIENTS

All patients who underwent colorectal stent placement.

INTERVENTION

Colorectal stent placement.

MAIN OUTCOME MEASUREMENTS

The occurrence of perforation with subgroup analyses for stent design, stricture etiology, stricture dilation, and concomitant chemotherapy, including the use of bevacizumab.

RESULTS

A total of 4086 patients underwent colorectal stent placement; perforation occurred in 207. Meta-analysis revealed an overall perforation rate of 7.4%. Of the 9 most frequently used stent types, the WallFlex, the Comvi, and the Niti-S D-type had a higher perforation rate (>10%). A lower perforation rate (<5%) was found for the Hanarostent and the Niti-S covered stent. Stenting benign strictures was associated with a significantly increased perforation rate of 18.4% compared with 7.5% for malignant strictures. Dilation did not increase the risk of perforation: 8.5% versus 8.5% without dilation. The subgroup of post-stent placement dilation had a significantly increased perforation risk of 20.4%. With a perforation rate of 12.5%, bevacizumab-based therapy was identified as a risk factor for perforation, whereas the risk for chemotherapy without bevacizumab was 7.0% and not increased compared with the group without concomitant therapies during stent therapy (9.0%).

LIMITATIONS

Heterogeneity; a considerable proportion of data is unavailable for subgroup analysis.

CONCLUSIONS

The perforation rate of colonic stenting is 7.4%. Stent design, benign etiology, and bevacizumab were identified as risk factors for perforation. Intraprocedural stricture dilation and concomitant chemotherapy were not associated with an increased risk of perforation.

Own experiences of endoscopic self-expandable stent placement for malignant colorectal ileus

Introduction

Acute low neoplasm ileus requires emergency surgery. Nowadays there are increased numbers of patients with comorbidities, which causes higher risk of intra- and postoperative complications.

Aim

To evaluate the clinical usefulness of endoscopic self-expandable stent placement for malignant colorectal ileus.

Material and methods

Twenty-one patients (8 women and 13 men), mean age 66.7 years, with low neoplasm obstruction, underwent endoscopic stenting of the stricture. This procedure was performed as a bridge to the surgery especially for high-risk patients. Eight of them had coagulation system impairment, 5 severe metabolic disorders, 4 circulatory insufficiency, 3 severe malnutrition and 1 patient undiagnosed synchronic rectal tumor. In 10 patients cancer was located in the sigmoid colon, in 7 in the rectum, in 2 in the ascending colon, and the transverse and ascending colon was involved in another 2 patients.

Results

All 21 patients (100%) underwent endoscopic stenting successfully. There were no complications after stent placement. The authors underline that placement of expandable metallic stents for patients with malignant colon obstruction with acute ileus is a safe and effective method. It gives an opportunity for quick balance of fluid, electrolyte, and the coagulation system and improvement of efficiency of the circulatory and respiratory system.

Conclusions

Endoscopic treatment of ileus helps precisely estimate tumor advancement and gives the possibility of a single stage radical surgical procedure.

Status and literature review of self-expandable metallic stents for malignant colorectal obstruction

Use of colorectal stents has increased dramatically over the last decades. Colorectal stents offer an alternative way to relieve fatal intestinal obstruction and can take place of emergency surgery, which associated with significant morbidity and mortality and a high incidence of stoma creation, to elective resection. Although there remain a few concerns regarding the use of stents as a bridge to surgical resection, use of self-expandable metallic stents for palliation in patients with unresectable disease has come to be generally accepted. Advantages of colorectal stents include acute restoration of luminal patency and allowance of time for proper staging and surgical optimization, and the well-known disadvantages are procedure-related complications including perforation, migration, and stent failure. General indications, procedures, and clinical outcomes as well as recent evidences regarding the use of colorectal stents will be discussed in this review.

Novel method of stent insertion for malignant lower rectal obstruction with proximal releasing delivery system (with video)

BACKGROUND

Self-expandable metal stents are an alternative to preoperative and palliative colostomy for patients with malignant colorectal obstruction. However, self-expandable metal stent placement is considered unsuitable or contraindicated for patients with malignant lower rectal obstruction within 5 cm of the anal verge because the exposed stent portion can irritate the distal rectum and cause anal pain and a foreign body sensation.

OBJECTIVE

To describe our experience with 6 patients with malignant lower rectal obstruction who underwent stent insertion with a proximal releasing delivery system (PRDS).

DESIGN

Prospective clinical series outcome study.

SETTING

A tertiary-care referral university hospital.

PATIENTS

This study involved all patients at our center who had a malignant lower rectal obstruction within 5 cm of the anal verge caused by rectal cancer and bladder cancer.

INTERVENTION

Uncovered stent with the PRDS with endoscopic and fluoroscopic guidance.

MAIN OUTCOME MEASUREMENTS

Technical and clinical success rate, adverse event rate, and stent migration rate.

RESULTS

All stents were placed at the expected location. Technical and clinical success rates were 100%. Two patients reported anal pain, which was controlled with analgesics. One case of tumor ingrowth occurred after 5 months and was treated with reinsertion of a stent with the PRDS. After stent insertion, the patients received chemotherapy, chemoradiotherapy, or conservative care.

LIMITATIONS

Small number of patients and no comparison group. Further prospective, randomized, controlled trials are needed.

CONCLUSIONS

Uncovered stent insertion with the PRDS is a feasible, safe, and effective treatment for the patient with malignant lower rectal obstruction within 5 cm from the anal verge.

Acute GI obstruction

Acute gastrointestinal obstruction occurs when the normal flow of intestinal contents is interrupted. The blockage can occur at any level throughout the gastrointestinal tract. The clinical symptoms depend on the level and extent of obstruction. Various benign and malignant processes can produce acute gastrointestinal obstruction, which often represents a medical emergency because of the potential for bowel ischemia leading to perforation and peritonitis. Early recognition and appropriate treatment are thus essential. The typical clinical symptoms associated with obstruction include nausea, vomiting, dysphagia, abdominal pain and failure to pass bowel movements. Abdominal distention, tympany due to an air-filled stomach and high-pitched bowel sounds suggest the diagnosis. The diagnostic process involves imaging including radiography, ultrasonography, contrast fluoroscopy and computer tomography in less certain cases. In patients with uncomplicated obstruction, management is conservative, including fluid resuscitation, electrolyte replacement, intestinal decompression and bowel rest. In many cases, endoscopy may aid in both the diagnostic process and in therapy. Endoscopy can be used for bowel decompression, dilation of strictures or placement of self-expandable metal stents to restore the luminal flow either as a final treatment or to allow for a delay until elective surgical therapy. When gastrointestinal obstruction results in ischemia, perforation or peritonitis, emergency surgery is required.

Evidence-based recommendations on colorectal stenting: a report from the stent study group of the korean society of gastrointestinal endoscopy

Recently, placement of self-expandable metallic stents has been used for the treatment of colorectal obstruction. As domestic awareness of colorectal cancer has increased, the number of colorectal stenting procedures performed has also increased. We aimed to provide evidence-based recommendations for colorectal stenting to aid gastroenterologists in making informed decisions regarding the management of patients who present with colorectal obstruction. The working group consisted of eight gastroenterologists who actively practice and conduct research in the field of colorectal stenting and are the members of the Stent Study Group of the Korean Society of Gastrointestinal Endoscopy. A literature search was conducted using the PubMed, Embase, KoreaMed, and the Cochrane Library databases to identify relevant articles published between January 2001 and June 2012. Based on the modified Delphi process, 10 recommendation statements regarding indications, usefulness, methodology and complications of colorectal stenting, and alternative treatments for malignant colorectal obstruction were determined. The contents will be widely distributed, and periodically revised to reflect the latest knowledge. These evidence-based recommendations for colorectal stenting will provide gastroenterologists and patients with appropriate and balanced information, and will improve the quality of care.

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.

Feasibility of a new self-expandable metallic stent for patients with malignant colorectal obstruction

AIM

Stent migration due to peristalsis of the colon is one of the unresolved complications of colonic self-expandable metallic stent (SEMS) placement. Axial force (AF), a recovery force of the stent to a straight position after bending, has been considered a factor influencing the conformability of the digestive tract. An uncovered SEMS (Niti-S Enteral Colonic Uncovered Stent, D-type; Taewoong, Inc., Gimpo, South Korea) with improved conformability is considered to decrease migration.

METHODS

Thirty three consecutive patients with symptomatic colorectal obstruction between March 2006 and December 2011 underwent endoscopic stent placement for palliation to estimate the efficacy and safety of Niti-S stents prospectively in four tertiary referral centers.

RESULTS

Technical and clinical success rates were 100% and 97%, respectively. Seventeen patients had the following complications: ingrowth (n = 6), overgrowth (n = 1), collapse of the SEMS (n = 1), stool impaction (n = 2), migration (n = 1), bleeding (n = 3), and tenesmus (n = 3). The patient with migration had no recurrent symptoms until death. Of these 17 patients, 10 required re-interventions. Seven patients underwent an additional SEMS implantation. One patient underwent surgery for stoma creation. Two patients had stool impaction, and they underwent endoscopic cleaning. The median duration of patency was 347.0 ± 65.5 days. The mean survival time after stent insertion was 240.1 ± 39.9 days.

CONCLUSION

The new SEMS effectively relieves malignant colorectal obstruction. Good conformability, according to the very low AF, may contribute to the low incidence of migration.

A temporary self-expanding metallic stent for malignant colorectal obstruction

AIM: To investigate the clinical safety and efficacy of a temporary self-expanding metallic stent (SEMS) for malignant colorectal obstruction.

METHODS: From September 2007 to June 2012, 33 patients with malignant colorectal obstruction were treated with a temporary SEMS. The stent had a tubular configuration with a retrieval lasso attached inside the proximal end of the stent to facilitate its removal. The SEMS was removed one week after placement. Clinical examination, abdominal X-ray and a contrast study were prospectively performed and both initial and follow-up data before and at 1 d, 1 wk, and 1 mo, 3 mo, 6 mo and 12 mo after stent placement were obtained. Data collected on the technical and clinical success of the procedures, complications, need for reinsertion and survival were analyzed.

RESULTS: Stent placement and removal were technically successful in all patients with no procedure-related complications. Post-procedural complications included stent migration (n = 2) and anal pain (n = 2). Clinical success was achieved in 31 (93.9%) of 33 patients with resolution of bowel obstruction within 3 d of stent removal. Eleven of the 33 patients died 73.81 ± 23.66 d (range 42-121 d) after removal of the stent without colonic re-obstruction. Clinical success was achieved in another 8 patients without symptoms of obstruction during the follow-up period. Reinsertion of the stent was performed in the remaining 12 patients with re-obstruction after 84.33 ± 51.80 d of follow-up. The mean and median periods of relief of obstructive symptoms were 97.25 ± 9.56 d and 105 ± 17.43 d, respectively, using Kaplan-Meier analysis.

CONCLUSION: Temporary SEMS is a safe and effective approach in patients with malignant colorectal obstruction due to low complication rates and good medium-term outcomes.

A systematic review and meta-analysis of randomized trials and prospective studies comparing covered and bare self-expandable metal stents for the treatment of malignant obstruction in the digestive tract

BACKGROUND

Self-expandable metal stents (SEMS) are widely used for the palliative treatment of malignant gastrointestinal obstruction. Our aim was to evaluate the evidence comparing covered and bare SEMS in the digestive tract using meta-analytical techniques.

METHODS

A literature search was performed using PubMed, Cochrane Library, and Embase databases for comparative studies assessing the two types of stents. The primary outcomes of interest were stent patency and patient survival; second outcomes included technical success, clinical success, tumor ingrowth, tumor overgrowth, and stent migration. A random-effects model was conducted. Pooled analysis was done separately based on the different segments of the digestive tract.

RESULTS

Eleven studies (8 randomized controlled trials and 3 prospective cohort studies) including a total of 1376 patients were identified. Covered SEMS were equivalent to bare SEMS in terms of technical success, clinical success, stent patency (gastroduodenal obstruction: HR =0.87, 95% CI 0.53-1.42; colorectal obstruction: HR =0.89, 95% CI 0.18-4.45; biliary obstruction: HR =0.73, 95% CI 0.41-1.32) and survival rates (esophageal obstruction: HR =1.80, 95% CI 0.73-4.44; gastroduodenal obstruction: HR =0.83, 95% CI 0.55-1.26; biliary obstruction: HR =0.99, 95% CI 0.77-1.28), although bare stents were more prone to tumor ingrowth (esophageal obstruction: RR =0.10, 95% CI 0.01-0.77; gastroduodenal obstruction: RR =0.12, 95% CI 0.03-0.55; colorectal obstruction: RR =0.21, 95% CI 0.06-0.70; biliary obstruction: RR =0.21, 95% CI 0.06-0.69), whereas covered stents had the higher risk of stent migration (gastroduodenal obstruction: RR =5.01, 95% CI 1.53-16.43; colorectal obstruction: RR =11.70, 95% CI 2.84-48.27; biliary obstruction: RR =8.11, 95% CI 1.47-44.76) and tumor overgrowth (biliary obstruction: RR =2.03, 95% CI 1.08-3.78).

CONCLUSION

Both covered and bare SEMS are comparable in efficacy for the palliative treatment of malignant obstruction in the digestive tract. Each type of the stents has its own merit and demerit relatively.

A prospective evaluation of short-term and long-term results from colonic stenting for palliation or as a bridge to elective operation versus immediate surgery for large-bowel obstruction

BACKGROUND

The efficacy and safety of self-expandable metallic stent (SEMS) placement as a bridge to elective surgery or definitive palliation versus emergency operation to treat colorectal obstruction is debated. This study aimed to evaluate the outcomes of patients with colorectal obstruction treated using different strategies.

METHODS

Subjects admitted to the authors' department with colorectal obstruction (n = 134) were studied prospectively. They underwent endoscopic stenting as a bridge to elective surgery (SEMS group: n = 49) or for definitive palliation (n = 34). A total of 51 patients underwent immediate surgery without stenting (NO-SEMS). Treatment was decided by the senior on-call surgeon.

RESULTS

Placement of SEMS was technically successful in 95.3 % and clinically successful in 98.7 % of cases. The short-term complications in the SEMS group were perforation (n = 1, 1.2 %), migration (n = 4, 4.9 %), occlusion (n = 4, 4.9 %), colon bleeding (n = 3, 3.7 %), and abdominal pain (n = 6, 7.4 %). The postoperative complication rate was 32.7 % in the SEMS group versus 60.8 % in the NO-SEMS group (P = 0.005), with a significant reduction in wound infections (26.5 vs 54.9 %; P = 0.004), abdominal abscess (14.3 vs 39.2 %; P = 0.006), respiratory morbidity (10.2 vs 37.3 %; P = 0.002), and intensive care treatment (10.2 vs 33.3 %; P = 0.007). The median postoperative hospital stay was 10 versus 15 days (P = 0.001). The in-hospital mortality rate in both groups was 2 %. Long-term follow-up evaluation showed less incisional hernia (6.3 vs 22.0 %; P = 0.04) and definitive stoma formation (6.3 vs 26.0 %; P = 0.01) in the SEMS group than in the NO-SEMS group, respectively. Kaplan-Meier survival curves showed a benefit for the SEMS group (log-rank test, 0.004). The long-term SEMS-related complication rate for the palliative patients was 43.8 %. The hospital readmission rate for SEMS complications was 34.4 %. Overall clinical success was 81.2 %.

CONCLUSIONS

In case of colorectal obstruction, endoscopic colon stenting as a bridge to elective operation should be considered as the treatment of choice for resectable patients given the significant advantages for short- and long-term outcomes. Palliative stenting is effective but associated with a high rate of long-term complications.

Favorable long-term clinical outcome of uncovered D-weave stent placement as definitive palliative treatment for malignant colorectal obstruction

BACKGROUND

Most self-expandable metallic stents for colorectal placement are uncovered because of the high migration rate of covered stents. However, the optimal stent design for colorectal use remains unclear.

OBJECTIVE

The purpose of this study was to evaluate the efficacy and safety of a double-wire woven uncovered stent for definitive palliative treatment of malignant colorectal obstruction.

DESIGN

This study was a prospective, single-arm, observational clinical study of patients enrolled between December 2005 and September 2010.

SETTINGS

This study was conducted at a referral hospital in Japan.

PATIENTS

Twenty-four consecutive patients with malignant colorectal obstruction were included in the study.

INTERVENTIONS

A double-wire woven uncovered stent was placed by use of a standard through-the-scope endoscopic placement technique.

MAIN OUTCOME MEASURES

Technical, initial clinical, and long-term clinical success were measured. Long-term clinical success was defined as sustained relief of obstructive symptoms without reintervention until the patient's death.

RESULTS

The Karnofsky performance status score before stent placement was 60 (median, interquartile range, 42.5-67.5). Twenty of 24 patients had primary colorectal cancer, and 4 had extracolorectal malignancies. The site of obstruction was the ascending colon in 10 patients, descending colon in 4 patients, sigmoid colon in 7 patients, and rectum in 3 patients. Technical, initial, and long-term clinical success rates were 100%, 100%, and 83%. Median stent patency time was 149 days (interquartile range, 45-198 days). Median survival time after stent placement was 155 days (interquartile range, 68-231 days). Four patients (17%) had negative outcomes including stent occlusion by tumor ingrowth (8%) and stent migration (8%). The highest Karnofsky performance status score after stent placement was 70 (median; interquartile range, 50-70). The Karnofsky performance status score improved after stent placement (p = 0.002).

LIMITATIONS

This study was limited because it was a single-arm, single-center study, and it had a small sample size.

CONCLUSIONS

Endoscopic placement of double-wire woven uncovered stents is effective and safe as definitive palliative treatment for patients with malignant colorectal obstruction.

Comparison of efficacy between uncovered and covered self-expanding metallic stents in malignant large bowel obstruction: a systematic review and meta-analysis

AIM

Insertion of a self-expandable metallic stent (SEMS) can rapidly relieve colorectal obstruction. This study aimed to compare the efficacy between uncovered and covered SEMSs in the treatment of malignant colorectal obstruction.

METHOD

A systematic search in Medline, Embase, the Cochrane controlled trials register and bibliographies of retrieved articles was performed. Randomized controlled trials and other comparative studies comparing uncovered and covered SEMSs for treatment of malignant colorectal obstruction were selected for this systematic review and meta-analysis. The main outcome measures were technical success, clinical success, tumour ingrowth, tumour overgrowth, early migration (≤ 7 days), late migration (> 7 days), overall complications and the duration of stent patency.

RESULTS

Compared with covered SEMSs, uncovered SEMSs were associated with a lower late migration rate (relative risk 0.25; 95% CI 0.08, 0.80; P = 0.02), a higher tumour ingrowth rate (relative risk 5.99; 95% CI 2.23, 16.10; P = 0.0004) and a prolonged stent patency (weighted mean difference 15.34 days; 95% CI 4.31, 26.37; P = 0.006). There was no significant difference in technical success, clinical success, tumour overgrowth, early migration, perforation or overall complications between the two groups.

CONCLUSION

Tumour ingrowth occurred more frequently in the uncovered SEMS group, while late migration was more common in the covered SEMS group.

Clinical outcomes of palliative self-expanding metallic stents in patients with malignant colorectal obstruction

OBJECTIVE

Self-expanding metallic stents (SEMS) are useful palliative option and a bridge to surgery in malignant colorectal obstruction. The aim of this study was to evaluate the clinical outcomes of SEMS to palliate colorectal malignant obstruction.

METHODS

Malignant colorectal obstructive patients who underwent SEMS insertion at the National Cancer Center, Korea from January 2004 to June 2008 were enrolled in the study. Patients' clinical characteristics, outcomes and complications for palliative SEMS insertion were retrospectively analyzed.

RESULTS

A total of 54 patients were enrolled in the palliative SEMS group and 48 patients with obstructive CRC were included in the SEMS as the bridge to surgery group. Obstruction of the left colon occurred in 52 patients of the palliative SEMS group and all patients in SEMS as bridge to surgery group. For primary SEMS insertion, the technical success (TS) rate was 87.0% and the clinical success (CS) rate 89.4%, while the rates of early and late complications were 24.1% and 23.4%, respectively. There was no procedure-related mortality. Stent migration rate was higher in the cases treated with small diameter and covered type of stents. Median time to reobstruction and migration were 85 and 101 days, respectively. TS and CS rates for SEMS reinsertion were comparable to those for primary SEMS insertion.

CONCLUSIONS

Palliative SEMS are effective and favorable procedures for malignant colorectal obstruction but with some complications. Stent migration is associated with covered type and small diameter stents while other factors including length of stent and chemotherapy do not affect stent complications in the present study.

Multivariate Analysis of the Survival Rate for Treatment Modalities in Incurable Stage IV Colorectal Cancer

PURPOSE

The aim of this study was to compare survival in patients that underwent palliative resection treatment versus non-resection for incurable colorectal cancer (ICRC).

METHODS

The case records of 201 patients with ICRC between January 2000 and December 2009 were reviewed. Demographics, American Society of Anesthesiologists (ASA) score, carcinoembryonic antigen (CEA) level, the location of the colon cancer, histology, metastasis, treatment options and median survival were analyzed retrospectively. We divided the patients into four groups according to the treatment modalities: resection alone, resection with post-operative chemotherapy, non-resection treatment by chemotherapy alone, and stent or bypass. Median survival times were compared according to each treatment option, and the survival rates were analyzed.

RESULTS

105 patients underwent palliative resection whereas 96 were treated with non-resection modalities. A palliative resection was performed in 44 cases for resection alone and in 61 cases for resection with post-operative chemotherapy. In patients treated with non-resection of the primary tumor, chemotherapy alone was done in 65 cases and stent or bypass in 31 cases. Multivariate analysis showed a median survival of 14 months in patients with palliative resections with post-operative chemotherapy, which was significantly higher than those for chemotherapy alone (8 months), primary tumor resection alone (5 months), and stent or bypass (5 months). Gender, age, ASA score, CEA level, the location of colon cancer, histology and the presence of multiple metastases were not independent factors in association with the median survival rate.

CONCLUSION

In the treatment of ICRC, palliative resection followed by post-operative chemotherapy shows the most favorable median survival compared to other treatment options.

Use of a nitinol stent to palliate a colorectal neoplastic obstruction in a dog

CASE DESCRIPTION

A 12-year-old castrated male Labrador Retriever was evaluated for clinical signs associated with colorectal obstruction.

CLINICAL FINDINGS

The dog had a 2-week history of tenesmus and hematochezia. On rectal examination, an annular colorectal mass was palpable extending orad into the pelvic canal. The original diagnosis of the colorectal mass was a mucosal adenoma. The dog was maintained on a low-residue diet and fecal softeners for a period of 13 months after initial diagnosis. At that time, medical management was no longer effective.

TREATMENT AND OUTCOME

Placement of a colonic stent was chosen to palliate the clinical signs associated with colorectal obstruction. By use of fluoroscopic and colonoscopic guidance, a nitinol stent was placed intraluminally to open the obstructed region. Placement of the stent resulted in improvement of clinical signs, although tenesmus and obstipation occurred periodically after stent placement. At 212 days after stent placement, the patient had extensive improvement in clinical signs with minimal complications; however, clinical signs became severe at 238 days after stent placement, and the dog was euthanized. Histologic evaluation of the rectal tumor from samples obtained during necropsy revealed that the tumor had undergone malignant transformation to a carcinoma in situ.

CLINICAL RELEVANCE

A stent was successfully placed in the colon and rectum to relieve obstruction associated with a tumor originally diagnosed as a benign neoplasm. Placement of colorectal stents may be an option for the palliation of colorectal obstruction secondary to neoplastic disease; however, clinical signs may persist, and continuation of medical management may be necessary.

Clinical outcomes and risk factors for technical and clinical failures of self-expandable metal stent insertion for malignant colorectal obstruction

BACKGROUND

Although self-expandable metal stent (SEMS) insertion is widely used for relief of malignant colorectal obstructions, the immediate technical and clinical failure rates of SEMSs and the associated risk factors remain largely unknown.

OBJECTIVE

To identify rates and factors predictive of technical and clinical failure of SEMSs when their use is attempted for the decompression of malignant colorectal obstruction.

DESIGN

Retrospective chart review.

SETTING

A tertiary-care academic medical center in South Korea.

PATIENTS

This study involved a total of 412 patients with malignant colorectal obstruction in whom SEMS insertion was attempted.

INTERVENTION

Placement of colonic SEMSs.

MAIN OUTCOME MEASUREMENTS

Technical success and immediate and long-term clinical success rates.

RESULTS

Technical and clinical failures were found in 36 of 276 patients (13.0%) and 39 of 240 patients (16.3%) in the palliative group, respectively, and in 3 of 136 patients (2.2%) and 7 of 133 patients (5.3%) in the preoperative group, respectively. Factors associated with technical failure were extracolonic origin of tumor, the presence of carcinomatosis, and a proximal obstruction site. Factors associated with long-term clinical failure in the palliative group were combined dilation procedure, no additional chemotherapy, and extracolonic origin of the tumor. In the preoperative group, only older patients had both higher technical failure and clinical failure rates.

LIMITATIONS

This was a single-institution, retrospective analysis.

CONCLUSION

Although colorectal SEMS placement is generally safe and effective, it is associated with clinically important technical and clinical failure rates. The identification of risk factors for the failure of colorectal SEMSs found in this study might help physicians decide between surgical decompression and endoscopic stenting in patients with malignant colorectal obstruction.

Enteral stents

The American Society for Gastrointestinal Endoscopy (ASGE) Technology Committee provides reviews of existing, new, or emerging endoscopic technologies that have an impact on the practice of GI endoscopy. Evidence-based methodology is used, with a MEDLINE literature search to identify pertinent clinical studies on the topic and a MAUDE (U.S. Food and Drug Administration Center for Devices and Radiological Health) database search to identify the reported complications of a given technology. Both are supplemented by accessing the "related articles" feature of PubMed and by scrutinizing pertinent references cited by the identified studies. Controlled clinical trials are emphasized, but in many cases, data from randomized, controlled trials are lacking. In such cases, large case series, preliminary clinical studies, and expert opinions are used. Technical data are gathered from traditional and Web-based publications, proprietary publications, and informal communications with pertinent vendors. Technology Status Evaluation Reports are drafted by 1 or 2 members of the ASGE Technology Committee, reviewed and edited by the committee as a whole, and approved by the Governing Board of the ASGE. When financial guidance is indicated, the most recent coding data and list prices at the time of publication are provided. For this review, the MEDLINE database was searched through August 2010 for articles related to enteral, esophageal, duodenal, and colonic stents. Technology Status Evaluation Reports are scientific reviews provided solely for educational and informational purposes. Technology Status Evaluation Reports are not rules and should not be construed as establishing a legal standard of care or as encouraging, advocating, requiring, or discouraging any particular treatment or payment for such treatment.

Outcomes of secondary stent-in-stent self-expandable metal stent insertion for malignant colorectal obstruction

BACKGROUND

Although self-expandable metal stents (SEMSs) are widely used for the treatment of malignant colorectal obstruction, they often become occluded by tumor ingrowth.

OBJECTIVES

To determine the therapeutic effectiveness of secondary stent-in-stent SEMS insertion for the management of occluded SEMS in patients with malignant colorectal obstruction and to identify predictive factors associated with clinical outcomes in terms of immediate clinical success, stent patency, and complications.

DESIGN

Retrospective case series.

SETTING

A tertiary-care academic medical center in South Korea.

PATIENTS

Between November 2005 and July 2010, among a total of 309 patients who underwent SEMS insertion for unresectable malignant colorectal obstruction at Severance Hospital, 87 underwent secondary SEMS insertion. Of these, 36 patients underwent secondary SEMS placement as stent-in-stent.

INTERVENTIONS

Placement of secondary colorectal stent-in-stent SEMSs.

MAIN OUTCOME MEASUREMENTS

Immediate and long-term clinical success and complications.

RESULTS

Immediate clinical success was achieved in 27 of 36 patients (75%), and the median duration of stent patency was 170 days. Factors associated with immediate clinical success included a long duration between the previous stent and stent-in-stent insertion. Moreover, the absence of carcinomatosis was associated with long-term clinical success.

LIMITATIONS

This was a retrospective, nonrandomized, single-center study.

CONCLUSIONS

Secondary stent-in-stent SEMS placement led to good outcomes in patients with malignant colorectal obstruction, despite a slightly lower success rate compared with primary SEMS placement. Patency duration of the primary SEMS and carcinomatosis were important factors predictive of immediate and long-term clinical success of stent-in-stent insertion, respectively.

Expandable metal stents for malignant colorectal strictures

The surgical management of malignant colorectal obstruction is still controversial and has higher associated mortality and complication rates compared with elective surgery. Placement of self-expanding metallic stents (SEMS) has been proposed as an alternative therapeutic approach for colonic decompression of patients with acute malignant obstruction. SEMS placement may be used both as a bridge to surgery in patients who are good candidates for curative resection and for palliation of those patients presenting with advanced stage disease or with severe comorbid medical illnesses.

Ten-year retrospective study of treatment of malignant colonic obstructions with self-expandable stents

PURPOSE

To describe the use of self-expandable metallic stents to manage malignant colorectal obstructions and to compare the radiation dose between fluoroscopic guidance of stent placement and combined endoscopic and fluoroscopic guidance.

MATERIALS AND METHODS

From January 1998 to December 2007, 467 oncology patients undergoing colorectal stent placement in a single center were included in the study. Informed consent was obtained in all cases. All procedures were performed with fluoroscopic or combined fluoroscopic and endoscopic guidance. Inclusion criteria were total or partial colorectal obstruction of neoplastic origin. Exclusion criteria were life expectancy shorter than 1 month, suspicion of perforation, and/or severe colonic neoplastic bleeding. Procedure time and radiation dose were recorded, and technical and clinical success were evaluated. Follow-up was performed by clinical examination and simple abdominal radiographs at 1 day and at 1, 3, 6, and 12 months.

RESULTS

Of 467 procedures, technical success was achieved in 432 (92.5%). Thirty-five treatments (7.5%) were technical failures, and the patients were advised to undergo surgery. Significant differences in radiation dose and clinical success were found between the fluoroscopy and combined-technique groups (P < .001). Total decompression was achieved in 372 cases, 29 patients showed remarkable improvement, 11 showed slight improvement, and 20 showed clinical failure. Complications were recorded in 89 patients (19%); the most significant were perforation (2.3%) and stent migration (6.9%). Mean interventional time and radiation dose were 67 minutes and 3,378 dGy·cm(2), respectively.

CONCLUSIONS

Treatment of colonic obstruction with stents requires a long time in the interventional room and considerable radiation dose. Nevertheless, the clinical benefits and improvement in quality of life justify the radiation risk.

Severity of initial stent angulation predicts reintervention after successful palliative enteral stenting for malignant luminal obstruction

BACKGROUND AND AIM

Recurrent stent obstruction necessitating reintervention is problematic and incompletely understood. The aim of the present study was to identify factor(s) predisposing to reintervention.

METHODS

Retrospective review of patients (n = 117) referred to a single major endoscopic referral centre for palliative enteral stenting from 1999 to 2006. Twelve were excluded due to inadequate follow-up data (n = 7) or initial radiographic documentation (n = 5). A total of 105 patients (gastroduodenal n = 57, colonic n = 48) were therefore analyzed. The primary outcome of interest was recurrent obstruction necessitating reintervention. Kaplan-Meier analysis of potential factors predisposing to reintervention, including stent angulation (mild [<15°], moderate [15°-90°], severe [>90°]) was completed for 98 patients (technically successful enteral stenting).

RESULTS

Technical and clinical success were achieved in 98 of 105 (93.3%) and 92 of 98 (93.9%) cases, respectively. Post-stenting median survival was 97.5 days (range 3-1054). Eighteen patients (18.4%) required reintervention for stent obstruction at a median time to reintervention of 85 days (range 7-481). Increased stent angulation (severe vs mild hazard ratio 6.73 (95% confidence interval 1.59-27.59), P = 0.009) was the only statistically significant factor in multivariate analysis predicting reintervention.

CONCLUSIONS

Despite its limitation as a retrospective review, this study found that reintervention for stent obstruction is necessary in almost one in five cases, and increasing severity of stent angulation is the most important risk factor.

Colonic stents: the modern treatment of colonic obstruction

Colonic stents traditionally have been used for the management of colorectal cancer, either as a palliative treatment or as a bridge to surgery. More recently, colonic stents have also been advocated as part of the therapy of benign strictures. A number of colonic stents are available worldwide, four of which are made in the USA. These stents are classified as covered or uncovered, with similar clinical applications. Technical and clinical success rates are similar among these different stents, as well as the rate of complications, which mainly consist of obstruction and migration. The deployment systems utilize fluoroscopy, endoscopy, or both. More recently, stents became available that are deployed "through the scope" (TTS) making the procedure faster. However, this advance does not exclude the use of fluoroscopy, particularly in those cases where the direct visualization of the proximal end of the stricture is absent. The increasing experience in the management of colorectal cancer with colonic stents decreases the morbidity and mortality, as well as cost, in comparison with surgical intervention for acute colonic obstruction. Management with colonic stents can also rule out proximal synchronous lesions after initial decompression prior to definitive surgery. Benign conditions may also be treated with stents. A multidisciplinary approach for the use of colonic stents during assessment and management of acute colonic obstruction is necessary in order to achieve a satisfactory outcome, whether that be better quality of life or improved survival.

Self-expandable metal stents (SEMS) can serve as a bridge to surgery or as a definitive therapy in patients with an advanced stage of cancer: clinical experience of a tertiary cancer center

BACKGROUND

Self-expandable metal stents (SEMS) can be used to relieve benign and malignant colorectal obstruction.

AIMS

The aim of this study was to determine the outcomes of SEMS for malignant colorectal obstruction.

METHODS

Retrospective review was done of patients who underwent endoscopic SEMS placement from 2001 to 2007.

RESULTS

Forty-six patients (23 M), mean age 60 years (range 24-82) underwent endoscopic SEMS placement. Cancer types included: 28 colorectal, and 18 metastatic cancers. The locations of the obstruction were as follows: two in the ascending colon, one in the hepatic flexure, three in the transverse colon, two in the splenic flexure, two in the descending colon, 26 in the sigmoid colon, and ten in the rectum. In 39 of the 46 cases (84.8%), placement of a single SEMS was successful covering the entire strictures, but in seven cases, two of the stents were placed in tandem resulting in adequate overage of stricture. Technical success was achieved in all cases. Clinical success was achieved in 39 out of 46 cases (84.8%). Two perforations were detected immediately and day 5 after SEMS placement, resulting in one death and one emergent surgery. Mean follow-up was 126 days (range 2-1,210). Twenty-eight of the 46 patients (61%) died during the follow-up period with the median overall survival being 3.52 months (95% CI: 2.34-4.41 months).

CONCLUSIONS

Placement of SEMS for the treatment of colorectal obstruction is feasible and safe. In our institution, where SEMS are primarily used to palliate terminal disease, technical and clinical success rates were high without significant morbidity and mortality. On long-term follow-up, patients died from their advanced disease with infrequent recurrent obstruction or stent-related complications.

Outcome of palliative self-expanding metal stent placement in malignant colorectal obstruction according to stent type and manufacturer

BACKGROUND

Self-expandable metallic stents (SEMS) of varying designs and materials have been developed to reduce complications, but few comparative data are available with regard to the type of stent and the stent manufacturer. We analyzed the success rates and complication rates, according to stent type (uncovered vs. covered stent) and individual stent manufacturer, in malignant colorectal obstruction.

METHODS

From November 2001 to August 2008, 103 patients were retrospectively included in this study: four types of uncovered stents in 73 patients and two types of covered stents in 30 patients. The SEMS was inserted into the obstructive site by using the through-the-scope method.

RESULTS

Technical and clinical success rates were not different between stent type or among stent manufacturers: 100 and 100% (p = ns) and 100 and 96.6% (p > 0.05), respectively, in uncovered and covered stents. Stent occlusion and migration rates were 12.3 and 3.3% (p = 0.274) and 13.7 and 16.7% (p = 0.761), respectively, in uncovered and covered stents, and 11.1, 5, and 9% (p = 0.761) and 25.9, 15, and 0% (p = 0.037) in Wallstent, Niti-S, and Bonastent uncovered stents, respectively.

CONCLUSIONS

The placement of SEMS is an effective and safe treatment for patients with malignant colorectal obstruction. Although minor differences in outcome were detected according to the type and the manufacturer of the stents, no statistically significant difference was observed, except in stent migration among the stent manufacturer.