Comparison of efficacies between stents for malignant colorectal obstruction: a randomized, prospective study

Newly designed flared-end covered versus uncovered self-expandable metallic stents for palliation of malignant colorectal obstruction: a randomized, prospective study

BACKGROUND/AIMS

Self-expandable metallic stents (SEMSs) are widely used as palliative or bridge to surgery treatments in patients with malignant colorectal obstruction (MCO). Stent occlusion is more common with uncovered stents, but stent migration is more common with covered stents. Our purpose was to compare the efficacy and safety of a newly designed covered SEMS with an uncovered proximal flared end (CSEMS-UPF) with that of the conventional uncovered SEMS (UCSEMS) in the treatment of MCO.

METHODS

This prospective randomized trial was conducted at a tertiary-care academic hospital. We enrolled 87 patients with stage 4 cancer and MCO: colorectal cancer in 60 patients and extracolonic cancer in 27 patients. Insertion of UCSEMS was randomly assigned to 43 patients, and 44 patients received the CSEMS-UPF. The primary outcome was the duration of stent patency after successful placement. The secondary outcomes were the number of patients with technical and clinical success and early and late complications from the stent insertion.

RESULTS

The median patency of the stent did not differ between the UCSEMS and CSEMS-UPF groups (484 [231-737] days vs. 216 [66-366] days, P= 0.242). The technical and clinical success rates did not differ significantly between the groups, either (100.0% vs. 93.2%, respectively, P= 0.241; 100.0% vs. 92.7%, respectively, P= 0.112), nor did the early (n = 2 [4.7%] vs. n = 4 [9.8%], P> 0.999) or late (n = 12 [27.9%] vs. n = 15 [36.6%], P> 0.999) stent complication rates differ between the groups.

CONCLUSIONS

The UCSEMS and newly developed CSEMS-UPF are similarly effective treatments for MCO, with no differences in the stent migration or occlusion rates (Clinical trial registration number: NCT02640781).

Impact of perforation following self-expandable metal stent as a bridge to surgery for malignant colorectal obstruction: a multicenter study of the Research Group for Stent in the Korean Society of Gastrointestinal Endoscopy

BACKGROUND AND AIMS

Self-expandable metal stents (SEMS) are effective in alleviating malignant colorectal obstruction. However, bowel perforation following SEMS placement remains a significant concern, as it can adversely affect oncological outcomes. This study aimed to evaluate the recurrence and overall survival rates associated with SEMS-related bowel perforations.

METHODS

This multicenter, retrospective analysis included patients with obstructive colorectal cancer who underwent SEMS placement as a bridge to surgery. The data collection period spanned from January 2008 to May 2019, with patient matching in a 1:5 ratio based on age, sex, tumor location, pathological stage, and achievement of curative resection.

RESULTS

Among the 412 patients who received SEMS placement, 25 (6.1%) patients experienced SEMS-related perforations (perforation group), with 21 instances classified as overt and four as silent perforations. Compared with 125 matched controls (non-perforation group), the perforation group showed elevated rates of emergent surgery, open surgery, and stoma formation, as well as a reduced interval from SEMS placement to surgery. The 5-year recurrence rate was notably higher in the perforation group than in the no-perforation group (47.4% vs. 21.5%, p < 0.001), whereas the 5-year survival rate was not significantly different between groups (63.8% vs. 80.0%, p = 0.330).

CONCLUSIONS

SEMS-related perforation led to less favorable surgical outcomes and a higher rate of recurrence, although no notable impact on overall survival was observed. Considering the risk of perforation, these findings support the cautious use of SEMS as a bridge to surgery.

Impact of self-expanding metal stents on long-term survival outcomes as a bridge to surgery in patients with colon cancer obstruction: Current state and future prospects

Since self-expanding metal stents (SEMS) were first introduced in acute colon cancer obstruction, the increased rate of primary anastomosis and improved quality of life following SEMS placement have been clearly shown. However, it was demonstrated that SEMS are associated with higher recurrence rates. Although several trials have shown that overall and disease-free survival in patients following SEMS placement is similar with patients undergoing emergency surgery, obstruction and a high incidence of recurrence imposed many concerns. The optimal time interval from SEMS to surgery is still a matter of debate. Some studies have recommended a time interval of ~2 weeks between SEMS insertion and elective surgery. A prolonged interval of time from SEMS insertion to elective surgery and the administration of neoadjuvant chemotherapy (NAC) has been proposed. SEMS-NAC might have advantages for improving the surgical and long-term survival outcomes of patients with acute colon cancer obstruction, which is an optional approach in the management of acute colon cancer obstruction.

Successful management of malignant colovesical fistula using covered colonic self-expanding metallic stent: a case report

BACKGROUND

A colovesical fistula (CVF) is commonly treated by resection of the intestine containing the fistula or creation of a defunctioning stoma. We herein report a case of successful fistula closure and avoidance of colostomy after placement of a covered colonic self-expanding metallic stent (SEMS) as a palliative treatment for a malignant CVF.

CASE PRESENTATION

A 75-year-old man undergoing infusional 5-fluorouracil and irinotecan chemotherapy plus bevacizumab for recurrent peritoneal dissemination of rectal cancer was admitted to our hospital because of fecaluria with a high-grade fever. Blood tests showed a moderate inflammatory reaction (white blood cell count, 9200/mm3; C-reactive protein, 11.03 mg/dL; procalcitonin, 1.33 ng/mL). Urinary sediment examination showed severe bacteriuria. Abdominal contrast-enhanced computed tomography showed intravesical gas, thickening of the posterior wall of the bladder, and irregular thickening of the sigmoid colon wall contiguous with the posterior bladder wall. Magnetic resonance imaging (MRI) clearly showed a fistula between the bladder and sigmoid colon. Colonoscopy revealed a circumferential malignant stricture 15 cm from the anal verge, and a fistula to the bladder was identified by water-soluble contrast medium. We diagnosed a complicated urinary tract infection (UTI) associated with a CVF due to peritoneal dissemination and started empirical treatment with sulbactam/ampicillin. Given the absence of active inflammatory findings around the fistula on MRI and the patient's physical frailty, we decided to place a covered SEMS to close the fistula. Under fluoroscopic and endoscopic guidance, a covered colonic SEMS of 80-mm length and 20-mm diameter was successfully deployed, and the fistula was sealed immediately after placement. Urine culture on day 3 after stenting was negative for bacteria, and a contrast study on day 5 showed no fistula. The patient was discharged home on day 6 with no complications. The UTI did not recur for 4 months after discharge.

CONCLUSIONS

A covered colonic SEMS was useful for sealing a malignant CVF in a patient unfit for surgery, and MRI was valuable to determine the status of the fistula. A covered colonic SEMS could be an alternative to surgical treatment for CVFs in patients who require palliative care.

Endoscopic stent placement with laparoscopic stent fixation in a patient with obstruction at a gastrojejunostomy anastomosis site

BACKGROUND

Palliative endoscopic stent placement may be considered in patients with malignant gastrointestinal obstruction. Stent migration is a potential complication, particularly for those placed at a surgical anastomosis or across a stricture caused by extra-alimentary tract factors. We report a patient with left renal pelvis cancer and gastrojejunostomy obstruction who underwent endoscopic stent placement and laparoscopic stent fixation.

CASE PRESENTATION

A 60-year-old male with peritoneal dissemination of a left renal pelvis cancer was admitted for treatment of upper gastrointestinal obstruction. A laparoscopic gastrojejunostomy had been previously performed for cancer invasion of the duodenum. Imaging showed gastroduodenal dilation and impaired passage of contrast medium through the efferent loop of the gastrojejunostomy. Gastrojejunostomy anastomosis site obstruction due to dissemination of left renal pelvis cancer was diagnosed. Conservative treatment failed and endoscopic stent placement with laparoscopic stent fixation was performed. After surgery, the patient was able to tolerate oral intake and he was discharged without complications. The patient gained weight and was able to resume chemotherapy, indicating the procedure was effective.

CONCLUSIONS

Endoscopic stent placement with laparoscopic stent fixation for malignant upper gastrointestinal obstruction appears effective in patients with a high risk of stent migration.

Arterial-colonic fistula secondary to colonic stent erosion into the left external iliac artery

Self-expandable metal stent (SEMS) are widely utilized as a bridge to surgical intervention and for palliative treatment of malignant bowel obstructions. The risk of complications associated with SEMS is low in well-selected patients. Stent erosion is a rare but serious adverse event that is associated with high morbidity and mortality. Here, we report the case of a 74-year-old patient with a colonic obstruction secondary to a pelvic mass that was treated with SEMS and radiotherapy, who developed a partial thickness stent erosion and recurrent hematochezia 6 years after placement. Endoscopic retrieval was not technically feasible. During attempted surgical resection, massive hemorrhage occurred from a colonic-arterial fistula to the left external iliac artery resulting in death. While SEMS remain an effective, minimally invasive approach for the management of bowel obstructions, prolonged in-situ lifetime may confer an increased risk of serious adverse events including erosion and fistula formation.

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.

AGA Clinical Practice Update on the Optimal Management of the Malignant Alimentary Tract Obstruction: Expert Review

BACKGROUND & AIMS

The purpose of this expert review is to describe the current methodologies available to manage malignant alimentary tract obstructions as well the evidence behind the various methods (including their efficacy and safety), indications, and appropriate timing of interventions.

METHODS

This is not a formal systematic review but is based on a review of the literature to provide best practice advice statements. No formal rating of the quality of evidence or strength of recommendation is carried out. BEST PRACTICE ADVICE 1: For all patients with alimentary tract obstruction, the decision about specific interventions should be made in a multidisciplinary setting including oncologists, surgeons, and endoscopists and take into account the characteristics of the obstruction, patient's expectations, prognosis, expected subsequent therapies, and functional status. BEST PRACTICE ADVICE 2: For patients who present with esophageal obstruction from esophageal cancer and who are potential candidates for resection or chemoradiation, clinicians should not routinely insert a self-expanding metal stent (SEMS) without multidisciplinary review because of high rates of stent migration, higher morbidity and mortality, and potentially lower R0 (microscopically negative margins) resection rates. BEST PRACTICE ADVICE 3: For patients who present with esophageal obstruction from esophageal cancer who are potential candidates for resection and who have concerns of malnutrition, clinicians may consider the use of enteral feeding tubes (via nasogastric or percutaneous route). Clinicians should be aware of the potential risk of abdominal wall tumor seeding as well as making subsequent gastric conduit formation difficult with percutaneous endoscopic gastrostomy placement. BEST PRACTICE ADVICE 4: For patients who present with esophageal obstruction from esophageal cancer who are not candidates for resection, clinicians should consider either SEMS insertion or brachytherapy as sole therapy or in combination. Clinicians should not consider the use of laser therapy or photodynamic therapy because of the lack of evidence of better outcomes and superior alternatives. BEST PRACTICE ADVICE 5: For patients with malignant esophageal obstruction who are undergoing SEMS placement, clinicians should use a fully covered or partially covered SEMS and not an uncovered SEMS, with consideration of a stent-anchoring/fixation method. BEST PRACTICE ADVICE 6: For patients with gastric outlet obstruction who have a life expectancy greater than 2 months, have good functional status, and who are surgically fit, surgical gastrojejunostomy should be considered. BEST PRACTICE ADVICE 7: For patients with gastric outlet obstruction who are undergoing surgical gastrojejunostomy, a laparoscopic approach is favored over an open approach because of lower blood loss and shorter hospital stay. BEST PRACTICE ADVICE 8: For patients with gastric outlet obstruction who are not candidates for gastrojejunostomy (surgical or endoscopic ultrasound-guided), clinicians should consider the insertion of an enteral stent. BEST PRACTICE ADVICE 9: Enteral stents should not be used in patients with multiple luminal obstructions or severely impaired gastric motility because of the limited benefit in these scenarios. Clinicians can consider placement of a venting gastrostomy in these patients. BEST PRACTICE ADVICE 10: Depending on the experience of the endoscopist, endoscopic ultrasound-guided gastrojejunostomy is an acceptable alternative to surgical gastrojejunostomy and enteral stent placement. Clinicians should be aware that there are currently no dedicated Food and Drug Administration-approved devices for endoscopic ultrasound-guided gastrojejunostomy. BEST PRACTICE ADVICE 11: For patients with malignant colonic obstruction who are candidates for resection, insertion of SEMS is a reasonable choice as a "bridge to surgery" to allow for one-stage, elective resection. BEST PRACTICE ADVICE 12: For patients with malignant colonic obstruction who are not candidates for resection, either SEMS placement or a diverting colostomy are reasonable choices depending on the patient's goals and functional status. BEST PRACTICE ADVICE 13: SEMS is a reasonable option for patients with proximal (or right-sided) malignant obstructions, both as a "bridge to surgery" and in the palliative setting. BEST PRACTICE ADVICE 14: SEMS placement is a reasonable alternative for patients with extracolonic malignancy who are not candidates for surgery, although their placement is more technically challenging, clinical success rates are more variable, and complications (including stent migration) are more frequent.

Factors Associated with Clinical Outcomes of Palliative Stenting for Malignant Colonic Obstruction

Background/Aims

Self-expandable metal stents (SEMSs) can be applied to relieve colorectal obstruction secondary to incurable primary colorectal cancer or extracolonic malignancy. We aimed to identify factors associated with clinical success and the reintervention-free survival (RFS) after palliative stenting.

Methods

Cases of palliative SEMS placement between 2005 and 2019 were retrieved from the institutional database and reviewed retrospectively. Logistic regression and log-rank testing followed by Cox proportional hazard analyses were performed to investigate the predictors of the clinical success of palliative stenting and factors associated with RFS, respectively.

Results

A total of 593 patients underwent palliative stenting for malignant colonic obstruction (MCO). The technical and clinical success rates were 92.9% and 83.5%, respectively. Peritoneal carcinomatosis was a predictor of clinical failure (odds ratio, 0.33; 95% confidence interval [CI], 0.17 to 0.65) in the multivariate analysis. Peritoneal carcinomatosis (hazard ratio [HR], 2.48; 95% CI, 1.69 to 3.64) and stent expansion >90% on day 1 (HR, 1.62; 95% CI, 1.05 to 2.50) were associated with a shorter RFS. Neither clinical success nor RFS was associated with extracolonic malignancy. Re-obstruction, stent migration, and perforation were responsible for most reinterventions after clinically successful palliative stenting.

Conclusions

In patients requiring palliative stenting for MCO, peritoneal carcinomatosis was associated with both clinical failure and short RFS. Stent expansion >90% on postprocedural day 1 was another predictor of a short RFS after clinically successful stenting. A large prospective study is warranted to establish factors associated with RFS after successful palliative stenting for MCO.

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.

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.

Performance Status Is a Predictive Factor of Improvement after Colonic Stenting in Patients with Malignant Stenosis due to Extraparenteral Malignant Tumors

Endoscopic stenting with self-expandable metallic stents is widely accepted for the treatment of malignant colorectal obstruction. Generally, stenting is performed as a bridge-to-surgery for primary colorectal cancer (CRC). Furthermore, palliative colonic stenting is performed for extraparenteral malignant tumors (EPMTs). However, predictive factors for improving clinical outcomes after colonic stenting for EPMTs remain unclear. This study is aimed at evaluating patients with EPMTs who underwent colonic stenting and investigating factors influencing clinical improvement after the stenting procedure. Twenty-one patients with colorectal obstruction by EPMTs were treated using self-expandable metallic stents over a period of 8 years. We divided the enrolled patients into the clinically improved and nonimproved groups after colonic stenting. Variables, including age; sex; type of primary cancer; serum albumin level; location of the obstruction; stent type, length, and diameter; prior chemotherapy treatment; ascites; Eastern Cooperative Oncology Group performance status (PS); technical and clinical success rates; stent-related adverse events; and mortality rates, were evaluated. Technical failure was not observed in all cases. Clinical success, defined as the passage of stool and improvement in the colorectal obstruction scoring system (CROSS) without adverse events, was observed in the 14 patients. Univariate analyses revealed no significant differences in factors other than PS before stenting (P = 0.04) between the improved and nonimproved groups. Colonic stenting for EPMTs was effective. PS may be an independent risk factor of clinical outcomes after stenting.

Stenting as a bridge to surgery for extra-colonic malignancy induced colorectal obstruction: preliminary experience

Background

The majority of colonic obstructions result from colorectal cancer. However, malignancies of extra-colonic origin can also disrupt colorectal patency, and the efficacy of self-expanding metal stents (SEMS) insertion as a bridge to surgery in these patients are still in debate. The aim of this study is to evaluate the efficacy of endoscopic stenting as a bridge to surgery (BTS) for extra-colonic malignancy (ECM)-induced colonic obstruction.

Methods

Thirty-three patients with colonic obstruction due to ECM who received self-expanding metal stents (SEMS) insertion at a single academic tertiary medical center between 2004 and 2015 were included. The purpose of SEMS insertion was determined based on whether the patient’s medical records indicated any surgical plans before SEMS insertion. Technical success was defined as a patent SEMS covering the entire length of the obstruction. Bridging success was defined as elective surgical procedures after the first SEMS insertion.

Results

Among the 33 patients who underwent SEMS insertion for colorectal obstruction due to ECM, nine underwent SEMS as a BTS. Technical success was achieved in 100% (9/9). Seven patients underwent elective surgery after successful decompression with the first SEMS, and the bridging success rate was 77.8% (7/9). Two patients needed secondary stent insertion before elective surgery. However, none of them required emergent surgery. No major complications occurred, including death related to colorectal endoscopic procedures, perforation, or bleeding.

Conclusion

SEMS insertion as a BTS is a good treatment option to avoid emergent surgery in patients with colonic obstruction caused by extra-colonic malignancy.

COMPARATIVE EVALUATION OF THE USE OF COATED AND UNCOATED SELF-EXPANDABLE METALLIC STENTS IN MALIGNANT COLORECTAL OBSTRUCTION

THE OBJECTIVE was to compare the efficacy and rate of complications in patients of groups with uncovered and covered colorectal stents.

METHODS AND MATERIALS. The study included 102 patients who were admitted for emergency with symptoms of malignant colon obstruction, who were randomly installed covered and uncovered SEMS from December 2012 to September 2017.

RESULTS. Clinical success was achieved with uncovered stents in 98 % of cases and 96 % with covered stents (relative risk (RR) 1.02). 95 % confidence interval (CI) 0.954–1.092). The incidence of complications in the group of uncovered stents was 9.8 %, in the group of covered stents – 3.9 % (RR 0.938, CI 0.841–1.046); the frequency of recurrences of obstruction did not significantly different between groups. The median duration of cumulative stent patency was 181 days in the group of uncovered stents and 218 days in the group of covered stents (p=0.427), the difference was statistically insignificant.

CONCLUSION. The use of double covered and double uncovered stents is equally effectively and safely for patients with malignant colorectal obstruction. The frequency of reobstructions did not exceed 4 % and did not differ in the groups of covered and uncovered stents. The choice of the type of stent should be determined individually depending on the clinical situation.

Laparoscopic Approach to Large Bowel Neoplastic Obstruction After Self-Expandable-Metal-Stent (SEMS) Placement

Endoscopic self-expandable metal stent (SEMS) placement as a bridge to surgery in large bowel neoplastic obstruction is an alternative to emergency surgery for the obstructive colorectal neoplasms. This study aims to analyze postoperative and long-term outcomes in a series of patients who underwent laparoscopic colorectal resection after SEMS placement. The analysis, after the stratification based on the time elapsed between the onset of the occlusive symptoms and the SEMS positioning, revealed an interesting result, with lower mortality for patients who underwent the procedure within 24 hours of hospitalization (P=0.0159). This trend may indicate the need to reduce the endoscopic time schedules as much as possible, even if an emergency procedure is needed. The laparoscopic approach, after stent placement as bridge therapy, can be a safe alternative to emergency surgery, if the procedure is precociously applied.

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.

Acute abdominal obstruction: Colon stent or emergency surgery? An evidence-based review

According to the American Cancer Society and Colorectal Cancer Statistics 2017, colorectal cancer (CRC) is one of the most common malignancies in the United States and the second leading cause of cancer death in the world in 2018. Previous studies demonstrated that 8%-29% of patients with primary CRC present malignant colonic obstruction (MCO). In the past, emergency surgery has been the primary treatment for MCO, although morbidity and surgical mortality rates are higher in these settings than in elective procedures. In the 1990s, self-expanding metal stents appeared and was a watershed in the treatment of patients in gastrointestinal surgical emergencies. The studies led to high expectations because the use of stents could prevent surgical intervention, such as colostomy, leading to lower morbidity and mortality, possibly resulting in higher quality of life. This review was designed to provide present evidence of the indication, technique, outcomes, benefits, and risks of these treatments in acute MCO through the analysis of previously published studies and current guidelines.

Outcomes of stent insertion and mortality in obstructive stage IV colorectal cancer patients through 10 year duration

BACKGROUND

Colorectal stents are frequently used in patients with stage IV colorectal cancer with obstruction. However, there are only few studies on changes in outcomes of these patients and on the effect of stents on outcome over a long period of time with ongoing changes in therapeutic strategy, including chemotherapy.

METHODS

We retrospectively evaluated 353 patients with bowel obstruction in stage IV colorectal cancer who underwent colonic stenting between years 2005 and 2014. The study population was divided into three groups based on time periods: 2005-2008, 2009-2011, and 2012-2014.

RESULTS

The frequency of colorectal stent insertion procedure increased over the time periods (13.8%, 18.3%, and 20.8%, respectively). There were no changes in success rate and total complication rate. However, the early complication rate in the 3rd period was significantly lower than in the other periods (15.4% vs. 17.1% vs. 7.2%; P = 0.039). In the multivariate analysis, carcinomatosis (hazard ratio, 1.478; 95% confidence interval, 1.016-2.149; P = 0.041) and covered or partial-covered stent (hazard ratio, 1.733; 95% confidence interval, 1.144-2.624; P = 0.009; hazard ratio, 1.988; 95% confidence interval, 1.132-3.493; P = 0.017, respectively) were associated with increased complication rate. Stent-related perforation was an independent risk factor related with increased mortality. Although survival duration increased over time (P = 0.042), the mortality rate was unchanged across the three time periods.

CONCLUSIONS

Over 10 years, the targeted agent use and survival duration increased, and early complication rate was decreased, without change in late complication rate or mortality rate during the three time periods in patients with obstructive stage IV colorectal cancer and stent insertion.

The factors influencing long-term outcomes of stenting for malignant colorectal obstruction in elderly group in community medicine

PURPOSE

Malignant bowel obstruction is a complication of colorectal carcinoma or metastasis from other carcinoma, and it causes significant damage on the condition of elderly patients; however, the self-expandable metallic stents (SEMSs) have been effectively used either for palliation or for bridging to the surgical procedure for this condition. The aim of this study was to investigate the factors influencing long-term outcomes of old-aged patients with SEMS for large bowel obstruction to develop the strategy for those patients in the community medicine.

METHODS

We performed a retrospective review of 42 patients with a median age of 83.0 years (range, 65-99 years), who underwent SEMS placement for malignant colorectal obstruction between 2006 and 2015 in our hospital. Univariate and multivariate logistic regressions were performed on data from the patients to assess the factors affecting 6-month survival without stent dysfunction.

RESULTS

The study population comprised 24 females (57.1%) and 18 males (42.9%). Of these, 38 patients (90.5%) received SEMS as palliation, whereas 4 patients (9.5%) underwent subsequent surgery. SEMSs were successfully inserted in 97.6% of patients. The median duration of follow-up was 205.0 days (range, 20-1377 days). On multivariate analysis, shorter stents (< 10 cm) yielded better outcomes than longer stents (≥ 10 cm) (P = 0.041), and the Cox proportional hazard model also indicated that shorter stents (P = 0.036) predicted longer event-free survival.

CONCLUSIONS

Elderly patients with malignant bowel obstruction receiving shorter stents had longer event-free survival after stenting with better general condition.

Using stents in the management of malignant bowel obstruction: the current situation and future progress

The use of self-expanding metal stents (SEMS) has been considered an effective and safe alternative to emergency surgery as bridge to surgery or for palliation in advanced colorectal cancer even though more recent data have raised concerns on both early and long-term outcomes when patients are treated with bridge to surgery indications. Areas covered: A comprehensive literature review of articles on endoscopic management of malignant bowel obstruction was performed. Indication, technique, outcomes, benefits and risks of these treatments in acute malignant colonic obstruction were reviewed. The clinical effectiveness and safety of SEMS in obstructive colorectal cancer, as bridge to surgery or for palliation compared to surgery, is discussed. Expert commentary: SEMS placement, when performed in tertiary level center with appropriate expertise in colorectal stenting, may have several advantages over surgery avoiding the potential for surgical morbidity in a typically frail group of patients even though these advantages are to be carefully balanced over the risk of life-threatening, stent-related complications.

Endoscopic stenting as bridge-to-surgery (BTS) in left-sided obstructing colorectal cancer: Experience with conformable stents

BACKGROUND

Compared to emergency surgery, self-expandable metallic stents are effective and safe when used as bridge-to-surgery (BTS) in operable patients with acute colorectal cancer obstruction. In this study, we report data on the new conformable colonic stents.

OBJECTIVES

To evaluate clinical effectiveness of conformable stents as BTS in patients with acute colorectal cancer obstruction.

DESIGN

This was a retrospective study.

SETTINGS

The study was conducted at six Italian Endoscopic Units.

PATIENTS

Data about patients with acute malignant colorectal obstruction were collected between 2007 and 2012.

MAIN OUTCOME MEASURES

All patients were treated with conformable stents as BTS. Technical success, clinical success, rate of primary anastomosis and colostomy, early and late complications were evaluated.

RESULTS

Data about 88 patients (62 males) were reviewed in this study. Conformable SEMS were correctly deployed in 86 out of 88 patients, with resolution of obstruction in all treated patients. Tumor resection with primary anastomosis was possible in all patients. A temporary colostomy was performed in 40. Early complications did not occur. Late complications occurred in 11 patients. Stent migration was significantly higher in patients treated with partially-covered stents compared to the uncovered group (35% vs. 0%, P<0.001). Endoscopical re-intervention was required in 12% of patients. One patient with rectal cancer had an anastomotic dehiscence after surgery and he was successfully treated with endoscopic clipping. One year after surgery, all patients were alive and local recurrence have not been documented.

LIMITATIONS

This was a retrospective and uncontrolled study.

CONCLUSIONS

Preliminary data from this large case series are encouraging, with a high rate of technical and clinical success and low rate of clinically relevant complications. Partially-covered SEMS should be avoided in order to reduce the risk of endoscopic re-intervention.

Radiologic Placement of Uncovered Stents for the Treatment of Malignant Colonic Obstruction Proximal to the Descending Colon

PURPOSE

To evaluate the safety, feasibility, and patency rates of radiologic placement of uncovered stents for the treatment of malignant colonic obstruction proximal to the descending colon.

MATERIALS AND METHODS

This was a retrospective, single-center study. From May 2003 to March 2015, 53 image-guided placements of uncovered stents (44 initial placements, 9 secondary placements) were attempted in 44 patients (male:female = 23:21; mean age, 71.8 years). The technical and clinical success, complication rates, and patency rates of the stents were also evaluated. Technical success was defined as the successful deployment of the stent under fluoroscopic guidance alone and clinical success was defined as the relief of obstructive symptoms or signs within 48 h of stent deployment.

RESULTS

In total, 12 (27.3 %) patients underwent preoperative decompression, while 32 (72.7 %) underwent decompression with palliative intent. The technical success rate was 93.2 % (41/44) for initial placement and 88.9 % (8/9) for secondary placement. Secondary stent placement in the palliative group was required in nine patients after successful initial stent placement due to stent obstruction from tumor ingrowth (n = 7) and stent migration (n = 2). The symptoms of obstruction were relieved in all successful cases (100 %). In the palliative group, the patency rates were 94.4 % at 1 month, 84.0 % at 3 months, 64.8 % at 6 months, and 48.6 % at 12 months.

CONCLUSIONS

The radiologic placement of uncovered stents for the treatment of malignant obstruction proximal to the descending colon is feasible and safe, and provides acceptable clinical results.

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.

Role of self expandable stents in management of colorectal cancers

Acute malignant colorectal obstruction is a complication of colorectal cancer that can occur in 7%-29% of patients. Self-expanding metallic stent placement for malignant colorectal obstruction has gained popularity as a safe and effective procedure for relieving obstruction. This technique can be used in the palliation of malignant colorectal obstruction, as a bridge to elective surgery for resectable colorectal cancers, palliation of extracolonic malignant obstruction, and for nonmalignant etiologies such as anastomotic strictures, Crohn’s disease, radiation therapy, and diverticular diseases. Self-expanding metallic stent has its own advantages and disadvantages over the surgery in these indications. During the insertion of the self-expanding metallic stent, and in the follow-up, short term and long term morbidities should be kept in mind. The most important complications of the stents are perforation, stent obstruction, stent migration, and bleeding. Additionally, given the high risk of perforation, if a patient is treated or being considered fortreatmentwith antiangiogenic agents such as bevacizumab, it is not recommended to use self-expanding metallic stent as a palliative treatment for obstruction. Therefore, there is a need for careful clinical evaluation for each patient who is a candidate for this procedure. The purpose of this review was to evaluate self-expanding metallic stent in the management of the obstruction of the colon due to the colorectal and extracolonic obstruction.

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.

Enteral stents for the management of malignant colorectal obstruction

Colorectal cancer (CRC) is the 3^rd most common cancer in the United States with more than 10000 new cases diagnosed annually. Approximately 20% of patients with CRC will have distant metastasis at time of diagnosis, making them poor candidates for primary surgical resection. Similarly, 8%-25% of patients with CRC will present with bowel obstruction and will require palliative therapy. Emergent surgical decompression has a high mortality and morbidity, and often leads to a colostomy which impairs the patient’s quality of life. In the last decade, there has been an increasing use of colonic stents for palliative therapy to relieve malignant colonic obstruction. Colonic stents have been shown to be effective and safe to treat obstruction from CRC, and are now the therapy of choice in this scenario. In the setting of an acute bowel obstruction in patients with potentially resectable colon cancer, stents may be used to delay surgery and thus allow for decompression, adequate bowel preparation, and optimization of the patient’s condition for curative surgical intervention. An overall complication rate (major and minor) of up to 25% has been associated with the procedure. Long term failure of stents may result from stent migration and tumor ingrowth. In the majority of cases, repeat stenting or surgical intervention can successfully overcome these adverse effects.

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.

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.

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.

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.

Complications and survival in patients undergoing colonic stenting for malignant obstruction

AIM: To investigate whether predicting patients that might be at a higher risk for complications might serve to improve the selection of patients undergoing colonic stenting.

METHODS: A retrospective review of consecutive patients who underwent an attempted self-expandable metal stent (SEMS) insertion for malignant colonic obstruction between November 2006 and March 2013. All patients were either referred for preoperative colonic decompression with the intent of a single surgical procedure, or for palliation of the malignant colorectal obstruction for unresectable cancer. Fisher’s test or χ² test was performed on categorical variables, and the t test for continuous variables. Univariable and multivariable logistic regression were used to examine the association between independent variables and the presence of complications from SEMS insertion.

RESULTS: SEMS insertion was attempted in 73 patients. Males comprised 55.71% and the mean age was 67.41 ± 12.41 years. Of these, 65.15% underwent subsequent surgery, while 34.85% received SEMS as palliation for advanced disease. Extracolonic tumors were only 4.76%. The majority of patients had stage IV disease (63.83%), while the remainder had stage III (36.17%). SEMS were successfully inserted in 93.85% (95%CI: 87.85%-99.85%). Perforations occurred in 4.10%, SEMS migration in 8.21%, and stent re-occlusion from ingrowth occurred in 2.74% of patients. The mean duration of follow up for the patients was 13.52 ± 17.48 mo (range 0-73 mo). None of the variables: age, sex, time between the onset of symptoms to SEMS insertion, time between SEMS insertion and surgery, length of the stenosis, location of the stenosis, albumin level, or receiving neoadjuvant chemotherapy, could predict the development of complications from either SEMS insertion nor prolonged survival.

CONCLUSION: None of the variables could predict the development of complications or survival. Further studies are required to identify patients who would benefit the most from SEMS.

Colorectal stenting as first-line treatment in acute colonic obstruction

Tumoral obstructions in almost the entire gastrointestinal tract can be resolved with interventional digestive endoscopy techniques. Self-expanding metal stent (SEMS) insertion in the obstructed colon is a minimally invasive and relatively simple procedure providing an effective first-line treatment for relief of acute malignant obstruction symptoms and serving either as a preoperative or “bridge to surgery” procedure or as palliative definitive care. This technique was introduced in the early 1990s. Although there is still debate about its real value, a lot of reports have been published since then and the procedure is advocated by many surgical groups as the method of choice for the initial treatment of left-sided tumoral colonic obstruction. Before the procedure, colonic obstruction has to be diagnosed by abdominal radiographs, water contrast enema and/or a computed tomography scan. The greatest information is provided by the latter and it is perhaps the method of choice prior to stenting. Skills and training are mandatory, as in all interventional procedures. The key step for success is to cross the malignant stricture with a guidewire. Care must be taken not to over insufflate an obstructed colon during the procedure. SEMS slide over the guidewire through the endoscope working channel or in parallel, outside the endoscope. An average 7% perforation rate has been reported during the procedure and other minor complications can appear in the follow up. However, as a whole, this technique seems to compare favorably with surgery.

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.

Palliative treatment for incurable malignant colorectal obstructions: a meta-analysis

AIM

To perform a meta-analysis of palliative stent placement vs palliative surgical decompression for management of incurable malignant colorectal obstructions.

METHODS

The databases of Medline, Web of Science, Embase, and the Cochrane Central Register of Controlled Trials were searched from their inception to July 2012 for studies (prospective, retrospective, randomized controlled trials, and case-control trials) designed as comparative analyses of patients with incurable malignant colorectal obstructions treated by self-expanding metallic stents (SEMS) or palliative surgery. No language restrictions were imposed. The main outcome measures were hospital stay, intensive care unit admission, clinical success rate, 30-d mortality, stoma formation, complications, and overall survival time. The data extraction was conducted by two investigators working independently and using a standardized form. The Mantel-Haenszel χ² method was used to estimate the pooled risk ratios with 95%CI under a fixed-effects model; when statistical heterogeneity existed in the pooled data (as evaluated by Q test and I² statistics, where P < 0.10 and I² < 25% indicated heterogeneity), a random-effects model was used.

RESULTS

Thirteen relevant articles, representing 837 patients (SEMS group, n = 404; surgery group, n = 433), were selected for analysis. Compared to the surgery group, the SEMS group showed lower clinical success (99.8% vs 93.1%, P = 0.0009) but shorter durations of hospital stay (18.84 d vs 9.55 d, P < 0.00001) and time to initiation of chemotherapy (33.36 d vs 15.53 d, P < 0.00001), and lower rate of stoma formation (54.0% vs 12.7%, P < 0.00001). Additionally, the SEMS group experienced a significantly lower rate of 30-d mortality (4.2% vs 10.5%, P = 0.01). Stent-related complications were not uncommon and included perforation (10.1%), migration (9.2%), and occlusion (18.3%). Surgery-related complications were slightly less common and included wound infection (5.0%) and anastomotic leak (4.7%). The rate of total complications was similar between these two groups (SEMS: 34.0% vs surgery: 38.1%, P = 0.60), but the surgery-related complications occurred earlier than stent-related complications (rate of early complications: 33.7% vs 13.7%, P = 0.03; rate of late complications: 32.3% vs 12.7%, P < 0.0001). The overall survival time of SEMS- and surgery-treated patients was not significantly different (7.64 mo vs 7.88 mo).

CONCLUSION

SEMS is less effective than surgery for palliation of incurable malignant colorectal obstructions, but is associated with a shorter time to chemotherapy and lower 30-d mortality.

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.

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.

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 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.

The learning curve for colorectal stent insertion for the treatment of malignant colorectal obstruction

BACKGROUND/AIMS

We aimed to assess the effectiveness of self-expanding metal stent (SEMS) insertion by evaluating the learning curve in relation to the experience of an endoscopist.

METHODS

We retrospectively analyzed the outcomes of 120 SEMS insertion procedures performed by one endoscopist in patients with malignant colorectal obstruction. We compared the technical and clinical success rates, complication rates, and duration of the procedures by quartiles.

RESULTS

The mean age of the patients (76 men and 44 women) was 64.6 years. The overall technical success rate was 95.0% (114/120), and the clinical success rate was 90.0% (108/120). The median procedure duration was 16.2 minutes (range, 3.4 to 96.5 minutes). From the first to the last quartile, the technical success rates were 90.0%, 96.7%, 96.7%, and 96.7% (p=0.263), and the clinical success rates were 90.0%, 90.0%, 96.7%, and 83.3% (p=0.588), respectively. Procedure-related complications were observed in 28 patients (23.3%). The complication rates for SEMS insertion when patients were divided by quartiles were 26.7%, 23.3%, 10.0%, and 33.3% (p=0.184), respectively. Moreover, the number of stents per procedure was 1.13, 1.03, 1.00, and 1.00 (p=0.029), respectively. The median duration of SEMS insertion decreased significantly, 20.9 to 14.8 minutes after the first 30 procedures (p=0.005).

CONCLUSIONS

An experienced endoscopist was able to perform the SEMS insertion procedure easily and effectively after performing 30 SEMS insertions.

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.