Comparison of Wallstent and Ultraflex stents for palliation of malignant left-sided colon obstruction: a retrospective, case-matched analysis

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- and long-term outcomes of self-expanding metallic stent placement vs. emergency surgery for malignant colorectal obstruction

The European Society of Gastrointestinal Endoscopy does not recommend self-expanding metal stent (SEMS) placement as a bridge to surgery (BTS) for malignant colorectal obstruction (MCRO). However, no universally accepted consensus has been determined. The present study aimed to evaluate the short- and long-term outcomes of SEMS placement vs. emergency surgery (ES) for MCRO. Surgical resection of colorectal cancer was performed in 3,840 patients between April 2001 and June 2016. Of these, 93 patients had MCRO requiring emergency decompression. Only patients in whom the colorectal lesion was ultimately resected were included; thus, the present study included 62 patients treated with MCRO via SEMS placement as a BTS (n=25) or via ES (n=37). The rates of laparoscopic surgery, primary anastomosis, stoma formation, lymph node dissection, adverse events, 30-day mortality and disease-free survival were evaluated. The clinical success rate of SEMS placement was 92.0% (23/25). Compared with the ES group, the SEMS group had higher rates of laparoscopic surgery (68.0 vs. 2.7%; P<0.001) and primary anastomosis (88.0 vs. 51.4%; P=0.003), a greater number of dissected lymph nodes (30 vs. 18; P=0.001), and lower incidences of stoma formation (24.0 vs. 67.6%; P=0.002) and overall adverse events (24.0 vs. 62.2%; P=0.004). The 30-day mortality and disease-free survival of the SEMS group were not significantly different to that of the ES group (0 vs. 2.7%; P=1.000; log-rank test; P=0.10). In conclusion, as long as adverse events such as perforation are minimized, SEMS placement as a BTS could be a first treatment option for MCRO. The present study is registered in the University Hospital Medical Network Clinical Trials Registry (UMIN R000034868).

Efficacy of uncovered colonic stents for extrinsic versus intrinsic malignant large bowel obstruction

BACKGROUND

Previous studies evaluating self-expandable metal stents (SEMS) for management of malignant extrinsic colon obstruction have yielded conflicting results. We evaluated the efficacy of uncovered SEMS for extrinsic colon malignancy (ECM) versus intrinsic colon malignancy (ICM).

METHODS

Retrospective review of all patients referred for colonic SEMS at a tertiary cancer center between 2007 and 2018 was performed. Primary outcome measures were technical success, clinical success, intervention rate, and overall survival.

RESULTS

138 patients with ECM and 119 patients with ICM underwent attempted stent placement. The rectum and/or sigmoid colon was the most common stricture site. Technical success was lower in the ECM group [86% vs 96% (p = .009)]. Clinical success was lower in the ECM group both at 7 days [82% vs 95% (p = .004)] and at 90 days [60% vs 86% (p < .001)]. Subsequent intervention was required more frequently [44% vs 35%; p = .23] and earlier [median 9 vs 132 days; p < .001] in the ECM group. Median overall survival in the ECM group was 92 vs 167 days. Among predictive variables analyzed, the ECM group had a higher frequency of peritoneal metastasis (87% vs 32%; p < .001), multifocal strictures with requirement for multiple stents (20% vs 6%; p = .002), sharp angulated strictures (39% vs 25%; p = .04) , and radiation therapy (21% vs 10%; p = .02).

CONCLUSIONS

Colonic SEMS for ECM is associated with lower technical and clinical success with earlier intervention rates compared with ICM. Our findings can be used to better inform patients and referring providers as well as guide new stent design to enhance efficacy in this population.

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.

Newly developed self-expandable Niti-S MD colonic metal stent for malignant colonic obstruction

BACKGROUND

Colonic stents are increasingly used to treat acute malignant colonic obstructions. The WallFlex and Niti-S D type stents are the commonly used self-expandable metallic stents available in Japan since 2012. WallFlex stent has a risk of stent-related perforation because of its axial force, while the Niti-S D type stent has a risk of obstructive colitis because of its weaker radial force. Niti-S MD type stents not only overcome these limitations but also permit delivery through highly flexible-tipped smaller-caliber colonoscopes.

AIM

To compare the efficacy and safety of the newly developed Niti-S MD type colonic stents.

METHODS

This single-center retrospective observational study included 110 patients with endoscopic self-expandable metallic stents placed between November 2011 and December 2018: WallFlex (Group W, n = 37), Niti-S D type (Group N, n = 53), and Niti-S MD type (Group MD, n = 20). The primary outcome was clinical success, defined as a resolution of obstructive colonic symptoms, confirmed by clinical and radiological assessment within 48 h. The secondary outcome was technical success, defined as accurate stent placement with adequate stricture coverage on the first attempt without complications.

RESULTS

The technical success rate was 100% in Groups W, N, and MD, and the overall clinical success rate was 89.2% (33/37), 96.2% (51/53), and 100% (20/20) in Groups W, N, and MD, respectively. Early adverse events included pain (3/37, 8.1%), poor expansion (1/37, 2.7%), and fever (1/37, 2.6%) in Group W and perforation due to obstructive colitis (2/53, 3.8%) in Group N (likely due to poor expansion). Late adverse events (after 7 d) included stent-related perforations (4/36, 11.1%) and stent occlusion (1/36, 2.8%) in Group W and stent occlusion (2/51, 3.9%) in Group N. The stent-related perforation rate in Group W was significantly higher than that in Group N (P < 0.05). No adverse event was observed in Group MD.

CONCLUSION

In our early and limited experience, the newly developed Niti-S MD type colonic stent was effective and safe for treating acute malignant colonic obstruction.

Endoscopic stenting in colorectal cancer

Acute malignant large bowel obstruction presents as one of the few emergencies of colorectal cancer (CRC). Management of this condition can either be by (I) upfront surgery or (II) the use of self-expanding metallic stent (SEMS) as a bridge to elective surgery. For patients with metastasis, the use of SEMS is reported to enable earlier commencement of chemotherapy. Although the use of SEMS in patients with acute malignant large bowel obstruction looks promising, it is plagued by its own set of complications and divided opinion over its long-term outcomes. Conflicting data are present, and definitive indication requires further evaluation and debate. This article will describe the typical presentation of patients with acute malignant large bowel obstruction. An introduction to the SEMS insertion procedural steps will be undertaken. Following which the article aims to review the safety profile of SEMS and the short- and long-term outcomes of SEMS in both the curative and palliative setting.

Long-term tumour outcomes of self-expanding metal stents as 'bridge to surgery' for the treatment of colorectal cancer with malignant obstruction: a systematic review and meta-analysis

PURPOSE

To explore the long-term oncological results of self-expanding metal stents (SEMS) as a surgical transition compared with those of simple emergency surgery.

METHODS

A systematic review of studies involving long-term tumour outcomes comparing SEMS with emergency surgery was conducted. All studies included information on 3-year and 5-year survival rates, 3-year and 5-year disease-free survival (DFS) rates, and local and overall recurrence rates; the results were expressed as odds ratios.

RESULTS

Overall, 24 articles and 2508 patients were included, including 5 randomised controlled trials, 3 prospective studies, and 16 retrospective studies. The 3-year survival rate (odds ratio (OR) = 0.88, 95% confidence interval (CI) 0.69-1.12, P = 0.05), 5-year survival rate (OR = 0.91, 95% CI 0.70-1.17, P = 0.67), 3-year DFS rate (OR = 1.14, 95% CI 0.91-1.42, P = 0.65), 5-year DFS rate (OR = 1.35, 95% CI 0.91-2.02, P = 0.17), overall recurrence rate (OR 1.04, 95% CI 0.77-1.41, P = 0.14), and local recurrence rate (OR 1.37, 95% CI 0.84-2.23, P = 0.92) were determined. There was no significant difference between the randomised and observational studies in the subgroup analysis, and the 5-year survival rate was higher in studies with a stent placement success rate of ≥ 95%.

CONCLUSION

SEMS implantation was a viable alternative in malignant left colon obstruction as a transition to surgery; its long-term survival results, including 5-year DFS and overall survival, were equivalent to those of emergent surgery.

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.

Colonic self-expanding metal stent (SEMS) as a bridge to surgery in left-sided malignant colonic obstruction: an 8-year review

INTRODUCTION

Colonic stenting has evolved to be an alternative to emergency laparotomy in the management of acute left-sided malignant colonic obstruction. This retrospective comparative study aimed to review the outcomes of colonic stent as bridge to surgery with emergency operation in a regional hospital in Hong Kong.

METHOD

Consecutive patients who were admitted from January 2006 to July 2014 with diagnosis of malignant left-sided colonic obstruction (from splenic flexure to rectosigmoid colon) were included. Patients with peritonitis or disseminated disease were excluded. Colonic stenting was attempted in all eligible patients when fluoroscopy was available in the endoscopy suite during office hour. Otherwise, emergency operation was performed. For patients with clinical success in colonic stenting, interval colectomies were performed. The postoperative outcomes, including the 30-days mortality, the stoma creation rate, the complication rate as well as the survival data were analyzed on an intention-to-treat (ITT) basis.

RESULTS

From January 2006 to July 2014, 62 patients underwent colonic stenting and 40 patients underwent emergency operations. The technical success rate and the clinical success rate of stenting were 95.2 and 83.9 %, respectively. Laparoscopic resection was achieved in 74.2 % in the stenting group. More primary anastomoses were performed in the stenting group (71.0 vs. 27.5 %, p = 0.000). The stenting group had a significantly lower permanent stoma rate (16.1 vs. 52.5 %, p < 0.000), fewer Dindo grade III to IV postoperative morbidity (16.1 vs. 40 %, p = 0.007), and the 30-day mortality rate was lower (3.2 vs. 17.5 %, p = 0.018), translating into a better overall 5-year survival rate. The disease-free survival was comparable between the two groups.

CONCLUSIONS

Colonic self-expanding metal stent is effective in the management of acute left-sided colonic obstruction. It is associated with reduced stoma creation rate and postoperative morbidity. The oncological safety is not jeopardized by stenting and the interval operation.

Self-expanding metallic stent improves histopathologic edema compared with transanal drainage tube for malignant colorectal obstruction

AIMS

To compare the usefulness of the self-expanding metallic stent (SEMS) with that of the transanal drainage tube (TDT) and emergency surgery after failure of decompression (ESFD) in patients with malignant colonic obstruction (MCO), and to evaluate post-decompression histopathologic changes.

METHODS

From January 2010 to June 2015, 39 patients with MCO received SEMS, TDT, and ESFD. We evaluated the outcomes including success rates of placement, clinical outcomes after decompression, and histopathologic findings of the resected specimens.

RESULTS

Technical success rates were 100% for SEMS and 78.9% for TDT. Clinical success rates were 100% for SEMS and 80.0% for TDT. Postoperative ileus was significantly less frequent after SEMS than after TDT (p = 0.014). Histopathologic edema grade was significantly lower for SEMS than for TDT and ESFD (p < 0.0001). There was no significant difference between edema grade and duration of decompression in the TDT group (p = 0.629), while all patients with SEMS were classified in a low edema grade (grade 0-2). The rate of stoma creation was significantly higher in patients with a high edema grade (grade 3) than in those with a low edema grade (grade 0-2) (p = 0.003). There was no microscopic perforation in any group.

CONCLUSION

Significantly greater resolution of histopathologic edema was achieved after placement of SEMS than after placement of TDT. These findings provide an indication of favorable clinical outcomes of SEMS in comparison with TDT and ESFD. This article is protected by copyright. All rights reserved.

Role of colonic stents in the management of colorectal cancers

Colorectal cancer is one of the commonly encountered cancers across the Western World. In United Kingdom, this constitutes third most common ranked cancer and second most common ranked cause of cancer related deaths. Its acute presentation as a malignant colonic obstruction imposes challenges in its management. Colonic stent has been used for many years to alleviate acute obstruction in such cases allowing optimisation of patient’s physiological status and adequate staging of cancer. In this review, current literature evidence regarding use of colonic stent in acute malignant colonic obstruction is critically appraised and recommendations on the use of colonic stent are advocated.

Self-Expanding Metallic Stents Versus Surgical Intervention as Palliative Therapy for Obstructive Colorectal Cancer: A Meta-analysis

BACKGROUND

Although self-expanding metallic stents (SEMS) are useful tools for relieving large bowel obstructions in patients with colorectal cancer (CRC), their efficacy in a palliative setting has not been validated. This meta-analysis aimed to evaluate the feasibility of SEMS as a palliation for unresectable CRC patients with bowel obstructions and to determine their contribution to the prognosis of CRC, compared with surgical intervention.

METHODS

We conducted a literature search of the PubMed and Cochrane Library databases. We selected all controlled trials that compared SEMS with surgical interventions as palliative treatments in unresectable obstructive CRC patients. The primary outcome was early complications, and the secondary outcomes were mortality, other morbidities, and long-term survival rates.

RESULTS

Ten studies met our inclusion criteria. SEMS significantly reduced the risk of early complications (odds ratio [OR] 0.34; 95% confidence interval [CI] 0.20-0.58%; P<0.01), mortality (OR 0.31; 95% CI 0.15%-0.64%; P<0.01), and stoma creation (OR 0.19; 95% CI 0.12-0.28%; P<0.01). Although SEMS placement was significantly associated with a higher risk of perforation of the large bowel (OR 5.25 95% CI 2.00-13.78%; P<0.01) and late complications (OR 1.94; 95% CI 0.90-4.19%; P=0.03), it also contributed significantly to better long-term survival (hazard ratio 0.46; 95% CI 0.31-0.68%; P<0.01).

CONCLUSIONS

Compared with surgical intervention, SEMS could provide feasible palliation for patients with bowel obstructions and unresectable CRC, because of their acceptable morbidity rates and better patient prognoses.

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.

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.

Stent-in-stent technique for removal of embedded partially covered self-expanding metal stents

BACKGROUND

Removal of embedded partially covered self-expanding metal stents (PCSEMS) is associated with an increased risk of adverse events compared with removal of fully covered self-expanding stents (FCSES) due to tissue ingrowth. Successful removal of embedded PCSEMS has been described by the stent-in-stent (SIS) technique.

AIMS

To report the first US experience from three high-volume quaternary care centers on the safety and efficacy of the SIS technique for removal of embedded PCSEMS.

METHODS

Retrospective study of outcomes for consecutive patients who underwent the SIS for removal of embedded PCSEMS over a 5-year period.

RESULTS

Twenty-seven embedded PCSEMS were successfully removed using the SIS technique (100 %) from 25 patients (11 males), median age 65 (range 37-80). All stents were successfully removed in one endoscopic session (no repeat SIS procedures were required for persistently embedded stents). The embedded PCSEMS had been in situ for a median of 76 days (range 26-501). Median SIS dwell time (FCSES in situ of PCSEMS) was 13 days (interquartile range 8-16 days; range 4-212 days). One adverse event (self-limited bleeding) occurred during a median follow-up period of 3 months (range 1-32). No patients died, required surgery, or had long-term disability due to adverse events attributed to the SIS technique. Twelve patients required additional interventions following SIS procedure for persistence or recurrence of the underlying pathology.

CONCLUSION

When performed by experienced endoscopists, safe and effective removal of embedded PCSEMS can be achieved via the SIS technique.

The Effectiveness of Self-Expandable Metallic Stent Insertion in Treating Right-Sided Colonic Obstruction: A Comparison between SEMS and Decompression Tube Placement and an Investigation of the Safety and Difficulties of SEMS Insertion in Right Colons

Objectives. Self-expandable metallic stent (SEMS) is widely used to treat malignant colonic obstruction. However, most reports about SEMS insertion have concentrated on the left colon. This study aimed to (1) investigate the effectiveness of SEMS insertion compared with conventional decompression tube for right-sided colonic obstruction and (2) compare the safety and technical success of SEMS insertion between left- and right-sided colonic obstructions. Methods. The data from thirty-seven patients who underwent SEMS or conventional decompression tube placement for malignant colonic obstruction in our hospital were analyzed retrospectively. Technical and clinical success, complications, and technical difficulties were analyzed. We compared the results between SEMS insertion and decompression tube placement in right colons and the outcomes of SEMS insertion between right- and left-sided colonic obstructions. Results. For right colons, the clinical success rate of SEMS insertion (100%) was significantly higher than that of decompression tube placement (55.9%). Concerning SEMS insertion, the technical difficulty and safety of SEMS insertion were similar between right- and left-sided colonic obstructions. Conclusion. SEMS insertion for right-sided colon is significantly more effective than conventional decompression tube placement, and this procedure was safer and less technically challenging than expected. SEMS insertion should be considered for treating right-sided malignant colonic obstruction.

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.

Analysis of risk factors associated with complications of colonic stenting for malignant obstruction

Self expanding metalic stent (SEMS) application can cause serious problems up to one third of the patients and some studies reported negative effect of SEMSs on survival in patients with malignancy. The SEMS type especially the rigid one like Wall-stent rather than more flexible type Ultraflex was also reported to have bad impact on the risk of perforation we believe that stent based management protocol for patients with non-perforating left sided obstructing colorectal cancer is a complex method that needs qualified medical and technical team.

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.

Influence of K-ras status and anti-tumour treatments on complications due to colorectal self-expandable metallic stents: a retrospective multicentre study

BACKGROUND

This study aimed to explore the relationship between K-ras status, anti-tumour treatments, and the complications of colorectal self-expandable metallic stenting in colorectal cancer.

METHODS

This is a retrospective, multicentre study of 91 patients with obstructive advanced colorectal cancer palliated with enteral stents between 2007 and 2011.

RESULTS

K-ras wild-type tumours were diagnosed in 44 patients (48.4%); 82 (90.1%) received chemotherapy and 45 (49.4%) had additional biological therapy (34 bevacizumab, 11 cetuximab). Twenty-one (23.1%) experienced stent-related complications: 11 (52.4%) occurred in the K-ras mutant group (P=0.9). K-ras wild-type patients were not less likely to develop adverse events than K-ras mutant patients (OR, 0.99; 95% CI: 0.4-2.7). Overall mean time to complication was 167.6 days (range 4-720 days), with no difference between the two groups (141 vs. 197 days; P=0.5). Chemotherapy did not influence the risk of complications (OR, 0.56; 95% CI: 0.14-2.9), and there was no evidence that patients treated with chemotherapy and cetuximab were more likely to experience stent-related complications than patients treated with chemotherapy alone, or untreated (OR, 1.2; 95% CI: 0.2-5.9). Although perforation rates were higher with bevacizumab-based treatment (11.8% vs. 7%), this result was not statistically significant (P=0.69).

CONCLUSIONS

K-ras mutation status, chemotherapy, and biological treatments should not influence colorectal stent-related complication rates.

Self-expandable metal stents for malignant colonic obstruction: data from a retrospective regional SIED-AIGO study

BACKGROUND

Self-expandable metal stents are a non-surgical option for the treatment of symptomatic malignant colorectal obstruction as palliative treatment or as a bridge to surgery.

AIMS

To report data from a regional study on self-expandable metal stent (SEMS) placement for malignant colorectal obstruction.

METHODS

Two hundred and four patients (male 54.9%, mean age of 69.5 ± 14.2) were retrospectively evaluated and data on technical and clinical success, and complications, were analyzed.

RESULTS

Technical and clinical success rates were 99% and 94.6% respectively, with 36.7% treated on an emergency basis and 63.3% electively. Palliative treatment was administered to 70.1%, and as a bridge to surgery for 29.9%. Complications were 17 neoplastic ingrowths, 10 stent migrations, and 4 perforations. Palliative treatment was associated with a higher risk of stent ingrowth (p=0.003), and chemotherapy with a lower risk of stent ingrowth (p=0.009).

CONCLUSION

This regional study, although it has certain limitations, confirms the positive role of self-expandable metal stents in the treatment of symptomatic malignant colorectal obstruction, and that chemotherapy decreases the risk of ingrowth.

The new nitinol conformable self-expandable metal stents for malignant colonic obstruction: a pilot experience as bridge to surgery treatment

Introduction. Self-expandable metal stents (SEMS) are a nonsurgical option for treatment of malignant colorectal obstruction also as a bridge to surgery approach. The new nitinol conformable stent has improved clinical outcomes in these kinds of patients. We report a pilot experience with nitinol conformable SEMS placement as bridge to surgery treatment in patients with colorectal obstruction. Materials and Methods. Between April and August 2012, we collected data on colonic nitinol conformable SEMS placement in a cohort of consecutive symptomatic patients, with malignant colorectal obstruction, who were treated as a bridge to surgery. Technical success, clinical success, and adverse events were recorded. Results. Ten patients (7 male (70%)), with a mean age of 69.2 ± 10.1, were evaluated. The mean length of the stenosis was 3.6 ± 0.6 cm. Five patients (50%) were treated on an emergency basis. The median time from stent placement to surgery was 16 days (interquartile range 7–21). Technical and clinical success was achieved in all patients with a significant early improvement of symptoms. No adverse events due to the SEMS placement were observed. Conclusion. This pilot study confirmed the important role of nitinol conformable SEMS as a bridge to surgery option in the treatment of symptomatic malignant colorectal obstruction.

A novel anchoring system for colonic stents: a pilot in vivo study in a porcine model

BACKGROUND

Colorectal stents have a proven role in colorectal cancer as palliative care or a bridge to surgery. However, their efficacy and anchoring to the tissue varies according to stent design with stent migration rates up to 50 %. We present preliminary in vivo results of a new end-luminal anchoring system for stent fixation to the rectal canal. The aim was to assess the efficacy and safety of the stent using the anchoring system while subjecting the device to daily abdominal pressures related to daily activities in a porcine animal model.

METHODS

Ex vivo anatomical and physical studies were performed to improve the system's structure and safety. Four female pigs were followed for the acute and chronic (16 weeks) period. Two animals were euthanized and underwent en-bloc pelvic visceral excision and histopathological examination. Device fixation time, animal behavior, device patency, anoscopic examination and histopathological features were assessed.

RESULTS

Mean anchoring time was 13.83 weeks (standard error ± 1.38 weeks). One of the animals experienced early device expulsion with no complications. No obstruction was noted in any of the animals. Macroscopic examination revealed mild focal submucosal scarring in one animal and a normal examination in the other. Hematoxylin and eosin staining revealed mucosal ulceration and mixed inflammatory cell infiltrate, with no signs of granulomata, foreign body giant cell reaction or microabscess formation.

CONCLUSIONS

A novel fixation device designed for long-term intrarectal implantation was well tolerated and maintained anal canal patency without migration. Larger studies are needed before its implementation in humans.

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.

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.

Angular positioning of stent increases bowel perforation after self-expandable metal stent placement for malignant colorectal obstruction

Background/Aims

Some factors like stent wires, balloon dilatation and use of guide wires seems to increase perforation after self-expandable metal stent (SEMS) placement, but few studies mentioned about the relationship between angulation of malignant stricture and perforation. The present study aimed to confirm that more angular positioning of stents increases perforation.

Methods

This study was conducted with retrospectively evaluation at Digestive Disease Center, CHA Bundang Medical Center, CHA University. Between January 2002 and August 2011, SEMS was inserted in 130 patients with malignant colorectal obstruction. We studied the difference in the angle of stenosis between perforation and non-perforation groups using fluorography images.

Results

SEMS insertion was performed in 130 cases of obstruction due to colon cancer. Perforation occurred in eight patients (6.2%) of them. Thirteen cases were excluded from the analysis due to poor fluoroscopic images. Among the eight patients with perforation, the mean stenosis angle was 109.9° compared to 153.1° in the nonperforation group, indicating that the angle was more acute in the perforation group (p=0.016).

Conclusions

This study shows that more angular positioning of stent increases bowel perforation after SEMS placement for malignant colorectal obstruction.

Clinical outcomes following secondary self-expandable metal stent (SEMS) insertion due to previous stent migration in malignant colorectal obstruction

BACKGROUND

There has been no research on the clinical outcomes of secondary self-expandable metal stent (SEMS) placement after initial stent migration. Therefore, this study aimed to assess the clinical outcomes of secondary SEMS placement after initial stent migration compared to the outcomes of secondary SEMS placement done for reasons other than migration and identify factors predictive of long-term outcomes.

METHODS

Between January 2005 and February 2011, a total of 422 patients underwent SEMS insertion for malignant colorectal obstruction at Severance Hospital. Of these, there were 98 cases of secondary SEMS placement, 38 of which were due to previous stent migration. We compared the clinical outcomes of secondary SEMS between stent migration and nonmigration groups. We also sought to identify risk factors for long-term outcomes of secondary SEMS after initial stent migration.

RESULTS

The baseline clinical characteristics were similar between the two groups. The technical and clinical success rates of secondary SEMS insertion in the migration and nonmigration groups were 94.7% and 83.3% (p = 0.09) and 73.7% and 53.3% (p = 0.122), respectively. In the migration group, sustained clinical success after secondary SEMS was associated with the absence of complications after insertion of the first stent (p < 0.001) and a longer time interval (more than 100 days) between the first and second stent insertion (p = 0.011).

CONCLUSIONS

Our data showed that secondary colorectal SEMS after stent migration is safe and effective. Moreover, the sustained clinical success of the secondary stent following migration was dependent on the outcomes of the first stent.

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.

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.

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.

Endoskopische Möglichkeiten der Behandlung von Nahtinsuffizienzen im Rektum

<b><i>Hintergrund: </i></b>Anastomoseninsuffizienzen stellen eine gefürchtete Komplikation der kolorektalen Chirurgie dar. Endoskopische Techniken haben sich in der Therapie der Leckagen zunehmend etabliert. In dieser Übersicht möchten wir einen Überblick der wichtigsten endoskopischen Verfahren geben. <b><i>Methode: </i></b>Systematische Recherche der vorhandenen Literatur. <b><i>Ergebnisse: </i></b>Die bedeutendsten endoskopischen Verfahren zur Behandlung der kolorektalen Anastomoseninsuffizienzen stellen die Fibrininjektion, die Vakuumschwammtherapie (Endo-Sponge), spezielle Clip-Systeme (OTSC) sowie die Stentimplantation dar. Der breiten klinischen Anwendung dieser Verfahren steht jedoch eine unzureichende Studienlage gegenüber. <b><i>Schlussfolgerung: </i></b>Die Einschätzung der Wertigkeit der einzelnen endoskopischen Verfahren untereinander und in speziellen therapeutischen Situationen hängt im Wesentlichen von der Erfahrung der Untersucher ab. Es bedarf der Durchführung randomisierter, prospektiver Studien, um diese Erfahrungen zu objektivieren.

Dual-design expandable colorectal stent for a malignant colorectal obstruction: preliminary prospective study using new 20-mm diameter stents

Objective

To evaluate the safety and effectiveness of a 20-mm diameter dual-design expandable colorectal stent for malignant colorectal obstruction.

Materials and Methods

The study series included 34 patients with malignant colorectal obstruction who underwent implantation of a 20-mm dual-design expandable colorectal stent in our department between March 2009 and June 2010. The 20-mm dual-design expandable colorectal stent was placed by using a 3.8-mm delivery system that had 28-mm diameter proximal and distal ends. Among the 34 patients, stent placement for palliation was performed in 20 patients, while stent placement for bridge to surgery was performed in 14 patients.

Results

A 97% (33 of 34) success rate was achieved for the stent placement. The perforation rate in the bridge to surgery group was 7% (1 of 14), compared to 0% (0 of 19) in palliative group. Migration occurred in one of 33 patients (3%) at 30 days after stent placement.

Conclusion

The placement of a 20-mm diameter dual-design stent appears to be clinically safe and effective for the management of colorectal obstruction, with low perforation and migration rates.

Colonic stenting as a bridge to surgery in malignant large-bowel obstruction: a report from two large multinational registries

OBJECTIVES

To date, this is the largest prospective series in patients with malignant colorectal obstruction to evaluate the effectiveness and safety of colonic self-expanding metal stents (SEMSs) as an alternative to emergency surgery. SEMSs allow restoration of bowel transit and careful tumor staging in preparation for elective surgery, hence avoiding the high morbidity and mortality associated with emergency surgery and stoma creation.

METHODS

This report is on the SEMS bridge-to-surgery subset enrolled in two multicenter international registries. Patients were treated per standard of practice, with documentation of clinical and procedural success, safety, and surgical outcomes.

RESULTS

A total of 182 patients were enrolled with obstructive tumor in the left colon (85%), rectum (11%), or splenic flexure (4%). Of these patients, 86% had localized colorectal cancer without metastasis. Procedural success was 98% (177/181). Clinical success was 94% (141/150). Elective surgery was performed in 150 patients (9 stomas) and emergency surgery in 7 patients for treatment of a complication (3 stomas). The overall complication rate was 7.8% (13/167), including perforation in 3% (5/167), stent migration in 1.2% (2/167), bleeding in 0.6% (1/167), persistent colonic obstruction in 1.8% (3/167), and stent occlusion due to fecal impaction in 1.2% (2/167). One patient died from complications related to surgical management of a perforation.

CONCLUSIONS

SEMSs provide an effective bridge to surgery treatment with an acceptable complication rate in patients with acute malignant colonic obstruction, restoring luminal patency and allowing elective surgery with primary anastomosis in most patients.

Colorectal stents for the management of malignant colonic obstructions

BACKGROUND

Colorectal cancer is one of the most common cancer in the western world. Acute colonic obstruction is one of the common presentations of colon cancer. Emergency surgical decompression is the traditional treatment of choice but is associated with high morbidity and mortality. In recent years colonic stents have been used to relieve the obstruction.

OBJECTIVES

The aim was to compare the colonic stenting versus emergency surgical decompression with regards to benefits and risks.

SEARCH METHODS

Searches were carried out May 2010 in the Cochrane Colorectal Cancer Specialised Register, the Cochrane Central Register of Controlled Trials, Ovid MEDLINE, Ovid EMBASE and Ovid CINAHL.

SELECTION CRITERIA

Randomised clinical trials comparing colonic stenting versus surgical decompression for obstructing colorectal cancers were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Data on the characteristics of the trial, methodological quality of the trials, mortality, morbidity, technical and clinical success rate, operating time, hospital stay and other measured secondary outcomes from each trial were collected. And the data were analysed with both the fixed-effect and the random-effects models using RevMan Analysis. For each outcome, odds ratio (OR) with 95% confidence intervals (CI) based on available data analysis was calculated.

MAIN RESULTS

Five randomised trials were identified with a total of 207 participants, 102 to colorectal stenting and 105 to emergency surgery. There was statistically significant higher clinical success rate in the emergency surgery group. The average time of clinical relief of obstruction was 0.66 day in the colonic stent group and was 3.55 days in the emergency surgery group. The stent insertion was successful in 86.02% of attempted stent placements. There was no statistically significant difference in the 30-day mortality between two groups. The 30 day mortality rate was similar, 2.3% in both groups. The stent related perforation rate was 5.88%. The stent migration rate was 2.13%. The stent obstruction rate was 2.13%. There was no statistically significant difference in overall complication rate in both groups. The complication rate was 39.22% in the colonic stent group and was 45.71% in the emergency surgery group. The mean hospital stay was 11.53 days in the colonic stent group and was 17.15 days in the emergency surgery group. The mean procedure/operating time was 113.93 minutes in the colonic stent group compared to 143.85 minutes in the emergency surgery group. The median blood loss was 50 ml in the colonic stent group and 350 ml in the emergency surgery group.

AUTHORS' CONCLUSIONS

The use of colonic stent in malignant colorectal obstruction seems to have no advantage over emergency surgery. The clinical success rate was statistically higher in emergency surgery group. However, use of colorectal stents seems to be as safe in the malignant colorectal obstruction as the emergency surgery with no statistically significant difference in the mortality and morbidity. Colorectal stents are associated with acceptable stent perforation, migration and obstruction rates. The advantages of colorectal stent includes shorter hospital stay and procedure time and less blood loss. However, due to the variability in the sample size and trial designs in the included studies, further randomised trials with bigger sample size and well defined trial design are needed to achieve the robust evidence.

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.

Through-the-scope large diameter self-expanding metal stent placement as a safe and effective technique for palliation of malignant colorectal obstruction: a single center experience with a long-term follow-up

OBJECTIVE

The aim of this study was to evaluate the outcomes of through-the-scope (TTS) large diameter self-expanding metal stent (SEMS) placement for palliation of malignant colorectal obstruction.

MATERIAL AND METHODS

Between January 2005 and December 2009, all patients who underwent endoscopic SEMS placement for palliation of malignant colorectal obstruction were prospectively enrolled.

RESULTS

Thirty-nine patients (17M and 22F; mean age 75.9 ± 10.6 years, range 50-91) were enrolled. The most frequent location was the sigmoid colon (13 cases). The causes of obstruction were colorectal malignancy in 32 patients and extracolonic malignancy in 7. Technical success was achieved in 36/39 patients (92.3%) and clinical success in 35/39 patients (89.7%). Technical failure was related to female sex (p = 0.04) and the extracolonic etiology of the stricture (p < 0.001). There were three early complications: two procedure-related perforations successfully managed conservatively and one hemorrhage treated with APC. Early complications were related to the location of strictures at the recto-sigmoid junction (p < 0.001). Late complications occurred in 10 patients: 8 of these patients experienced occlusive symptoms (attributable to tumor ingrowth in 5 cases and stool impaction in 3 cases); the remaining 2 were one case of tumor ingrowth with sub-occlusive symptoms and hemorrhage, and one case of distal migration. There was no procedure-related mortality and all complications were managed without surgical intervention. SEMS patency duration was 236 ± 128 days (range 31-497) and mean survival of the patients was 259 ± 121 days (range, 32-511).

CONCLUSIONS

In our experience, TTS large-diameter SEMS placement is a safe and effective treatment for palliation of malignant colorectal obstruction.

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.

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.

Colonic perforation after stent placement for malignant colorectal obstruction--causes and contributing factors

Self-expanding metal stents (SEMS) are used to manage malignant colorectal obstruction. Colonic perforation is the most worrisome complication from colonic stenting. We reviewed causes and contributing factors of perforation with colonic stent placement in patients with malignant colorectal obstruction. Articles from both English and foreign language publications were identified from Medline. Data were collected on causes, timing, treatment and mortality related to perforation. A total of 2287 patients from 82 articles were included in this analysis, which showed an overall perforation rate of 4.9%. Perforation rates for palliation and bridge to surgery (BTS) were not significantly different (4.8% vs. 5.4%, p = 0.66); over 80% occurred within 30 days of stent placement (half during or within one day of the procedure). The mortality rate related to perforation was 0.8% per stented patient, but the mortality of patients experiencing perforation was 16.2%. There was no significant difference (p = 0.78) in the mortality rates between the palliation and the BTS group and concomitant chemotherapy, steroids, and radiotherapy are risk factors of perforation. The overall perforation related mortality is far less than that of patients undergoing emergency surgery for bowel obstruction.

Fluoroscopic management of complications after colorectal stent placement

Colorectal self-expanding metal stents have been widely used as a bridge to surgery in patients with acute malignant colonic obstruction by allowing a single-stage operation, or as a definitive palliative procedure in patients with inoperable tumors. Colonic stents are placed under either fluoroscopic or combined endoscopic and fluoroscopic guidance, with similar technical-success and complication rates. Placement of colonic stents is a very safe procedure with a low procedure-related mortality rate, but serious complications can develop and reinterventions are not uncommon. Most of the complications can be treated by minimally invasive or conservative techniques, while surgical interventions are required for most patients with perforation.

Efficacy and safety of colonic stenting for malignant disease in the elderly

BACKGROUND

Self-expandable metal stents (SEMS) are an accepted palliation for malignant colorectal obstruction. Outcomes of stent insertion solely in older patients are unknown.

OBJECTIVE

To compare outcomes of SEMS insertion for malignant colorectal disease, in older versus younger patients.

METHODS

Forty-three patients were retrospectively identified as having undergone SEMS insertion for obstructing colorectal cancer. Of these, 24 were > or = 70 years of age (older patient group) and 19 were <70 years of age (younger patient group).

RESULTS

There was no significant difference in successful SEMS insertion between the groups (88% in older versus 100% in younger patients, p > 0.05). Furthermore, the complication rate was similar in both groups (12.5% versus 26%, p > 0.10). There was no difference in median survival (113 days versus 135 days, p > 0.09).

CONCLUSION

Colorectal stenting for malignant disease in older patients is both safe and effective with comparative success and complication rates to a younger population.

Comparison of ultraflex and niti-s stents for palliation of unresectable malignant gastroduodenal obstruction

AIM

Self-expandable metallic stents are widely used for palliation of malignant gastric outlet obstruction (GOO), but clinical outcomes of different stents have not been compared. Here, we compared outcomes in patients with a GOO receiving either an Ultraflex (UF) or a Niti-S (NS) stent.

METHODS

Prospective outcomes in 53 patients receiving palliative placement of an NS stent for symptomatic GOO over a 3-year period were compared with those obtained retrospectively in 31 patients receiving a UF stent in a previous 5-year period. Main outcome measurement was between-group comparison of clinical outcome, complications, and reintervention.

RESULTS

Baseline characteristics between the groups were comparable. No difference in technical or clinical success rate was observed. Median procedure time for NS placement was shorter than for UF (15 vs 40 min; P < 0.0001). Complications were more frequent with NS than with UF placement, albeit without statistical significance (16% vs 25%). Although two severe complications occurred in each group, neither was stent related in the NS group. Reintervention was more frequent in the NS group (3% vs 21%; P = 0.0485). Median survival time was 53 versus 88 days for UF versus NS stents, respectively.

CONCLUSION

Although no significant difference was seen with regard to feasibility, reintervention was less frequent with UF stents than with NS stents. However, UF stents require much more procedure time, and a complicated and difficult placement procedure. These observations suggest that although NS stents placed using a through-the-scope technique may be more patient friendly than UF stents, further optimization of through-the-scope stents is still required. Further prospective comparison of NS and UF stents in GOO treatment is warranted.