Outcome of 141 cases of self-expandable metallic stent placements for malignant and benign colorectal strictures in a single center

Outcomes of colon self–expandable metal stents for malignant vs benign indications at a tertiary care center and review of literature

BACKGROUND

Endoscopic placement of a self-expandable metal stent (SEMS) is a minimally invasive treatment for use in malignant and benign colonic obstruction. However, their widespread use is still limited with a nationwide analysis showing only 5.4% of patients with colon obstruction undergoing stent placement. This underutilization could be due to perceived increase risk of complications with stent placement.

AIM

To review long- and short-term clinical success of SEMS use for colonic obstruction at our center.

METHODS

We retrospectively reviewed all the patients who underwent colonic SEMS placement over a eighteen year period (August 2004 through August 2022) at our academic center. Demographics including age, gender, indication (malignant and benign), technical success, clinical success, complications (perforation, stent migration), mortality, and outcomes were recorded.

RESULTS

Sixty three patients underwent colon SEMS over an 18-year period. Fifty-five cases were for malignant indications, 8 were for benign conditions. The benign strictures included diverticular disease stricturing (n = 4), fistula closure (n = 2), extrinsic fibroid compression (n = 1), and ischemic stricture (n = 1). Forty-three of the malignant cases were due to intrinsic obstruction from primary or recurrent colon cancer; 12 were from extrinsic compression. Fifty-four strictures occurred on the left side, 3 occurred on the right and the rest in transverse colon. The total malignant case (n = 55) procedural success rate was 95% vs 100% for benign cases (P = 1.0, NS). Overall complication rate was significantly higher for benign group: Four complications were observed in the malignant group (stent migration, restenosis) vs 2 of 8 (25%) for benign obstruction (1-perforation, 1-stent migration) (P = 0.02). When stratifying complications of perforation and stent migration there was no significant difference between the two groups (P = 0.14, NS).

CONCLUSION

Colon SEMS remains a worthwhile option for colonic obstruction related to malignancy and has a high procedural and clinical success rate. Benign indications for SEMS placement appear to have similar success to malignant. While there appears to be a higher overall complication rate in benign cases, our study is limited by sample size. When evaluating for perforation alone there does not appear to be any significant difference between the two groups. SEMS placement may be a practical option for indications other that malignant obstruction. Interventional endoscopists should be aware and discuss the risk for complications in setting of benign conditions. Indications in these cases should be discussed in a multi-disciplinary fashion with colorectal surgery.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Uncovered self-expandable metal stents for the treatment of refractory benign colorectal anastomotic stricture

Self-expandable metal stent (SEMS) placement has been suggested as a therapeutic modality for treating benign colorectal strictures. Covered stents are generally used, given the concerns regarding the efficacy and safety of uncovered stents. Hence, few studies have evaluated the efficacy and safety of uncovered SEMSs (UCSEMSs) in patients with refractory benign colorectal anastomotic strictures. In this study, 12 patients with postoperative benign symptomatic anastomotic strictures refractory to pneumatic dilation (range, 2–9) and transient indwelling-covered SEMSs were treated using UCSEMS. All enrolled patients were men (mean age, 61 years). Stent placement was successful in all 12 patients, and early clinical success was achieved in 11 (92%) patients. Four patients (25%) showed successful clinical outcomes without further intervention, but eight patients (75%) were clinically unsuccessful, and showed stricture recurrence or functional obstructive symptoms. Three patients underwent surgery, and the remaining five patients required repeat stent procedures. Despite the high reobstruction rate, the median follow-up period after UCSEMS placement was 16.7 months, demonstrating that UCSEMS may be able to achieve medium-term symptom relief without any complications. Therefore, UCSEMS may be an alternative option in exceptional circumstances in carefully selected patients, where invasive surgical treatments, such as stoma diversion, are not an option, thereby improving patients’ quality of life.

Detection of circulating colorectal cancer cells by a custom microfluid system before and after endoscopic metallic stent placement

Although the detection of circulating tumor cells (CTCs) should be crucial for future personalized medicine, no efficient and flexible methods have been established. The current study established a polymeric custom-made chip for capturing CTCs with a high efficiency and flexibility. As an example of clinical application, the effects of self-expandable metallic stent (SEMS) placement on the release of cancer cells into the blood of patients with colorectal cancer and bowel obstruction were analyzed. This was assessed as the placement of SEMS may cause mechanical damage and physical force to malignant tissue, increasing the risk of cancer cell release into the bloodstream. The present study examined the number of CTCs using a custom-made chip, before, at 24 h after and at 4 days after SEMS placement in patients with colorectal cancer. The results revealed that, among the 13 patients examined, the number of CTCs was increased in three cases at 24 h after SEMS placement. However, this increase was temporary. The number of CTCs also decreased at 4 days after stent placement in most cases. The CTC chip of the current study detected the number of CD133-positive cancer stem-like cells, which did not change, even in the patient whose total number of CTCs temporarily increased. The results indicated that this custom-made microfluid system can efficiently and flexibly detect CTCs, demonstrating its potential for obtaining information during the management of patients with cancer.

Endoscopic stenting of malignant, benign and iatrogenic colorectal disorders: a primer for radiologists

In recent years, endoscopic placement of intraluminal stents is increasingly used to manage a widening range of colorectal disorders. Self-expanding metal stents represent an established alternative to surgery for the palliation of unresectable carcinomas and currently allow a "bridge-to-surgery" strategy to relieve large bowel obstruction and optimise the patients' clinical conditions before elective oncologic resection. Additionally, intraluminal stents represent an appealing option to manage obstructing extracolonic tumours and selected patients with benign conditions such as refractory anastomotic strictures and post-surgical leaks.This educational paper reviews the technical features and current indications of colorectal stenting and presents the expected and abnormal radiographic, CT and MRI appearances observed during the endoscopic management of malignant, benign and iatrogenic colonic disorders with stents. The aim is to provide radiologists with a thorough familiarity with stent-related issues, which is crucial for appropriate reconstruction of focused CT images, correct interpretation of early post-procedural studies and elucidation of stent-related complications such as misplacement, haemorrhage, perforation, migration and re-obstruction.

The ability of positron emission tomography/computed tomography to detect synchronous colonic cancers in patients with obstructive colorectal cancer

Positron emission tomography/computed tomography (PET/CT) is frequently used to detect colorectal cancer. The present retrospective study assessed the ability of PET/CT to identify synchronous colonic lesions in 72 patients with obstructive colorectal cancer. All patients had undergone surgical resection without undergoing preoperative total colonoscopy (TCS) at the Digestive Disease Center (April 2007 to September 2016), and subsequently underwent TCS of the proximal colon within 2 years post-surgery. A total of 11 patients exhibited 18F-fluorodeoxyglucose uptake during PET/CT of the proximal colon (4 invasive cancers, 3 advanced adenomas and 4 false-positive results), and 61 patients had no uptake in the proximal colon. Among these 61 patients, postoperative TCS revealed 2 invasive cancers and 4 advanced adenomas. The sensitivity of PET/CT for detecting synchronous invasive cancers was 66.6% (4/6), with a specificity of 89.4% (59/66), a positive predictive value of 36.4% (4/11), a negative predictive value of 96.7% (59/61), and an accuracy of 87.5% (63/72). Negative PET/CT results indicated a low probability of synchronous lesions in the proximal colon. Thus, PET/CT may be a useful tool for detecting synchronous colonic cancers in patients with obstructive colon cancer.

Colonic stent-induced mechanical compression may suppress cancer cell proliferation in malignant large bowel obstruction

BACKGROUND

The short-term safety and efficacy of insertion of a self-expandable metallic colonic stent (SEMS) followed by elective surgery, "bridge to surgery (BTS)", for malignant large bowel obstruction (MLBO) have been well described; however, the influence on long-term oncological outcomes is unclear. The aim of this study was to evaluate changes in oncological characteristics in colorectal cancer (CRC) tissues after SEMS insertion, focusing on growth factors, cell cycle and apoptosis.

METHODS

From January 2013 to September 2014, a total of 25 patients with MLBO who underwent BTS at our single institution were retrospectively included. Paired CRC tissue samples before (endoscopic biopsy) and after SEMS insertion (surgically resected) were collected from each patient. EGFR, VEGF, Ki-67, p27^kip1 and TUNEL expression were determined by immunohistochemistry.

RESULTS

No clinical or subclinical perforations evaluated by mechanical ulceration pathologically were observed. Epithelial exfoliation, tumour necrosis, infiltration of inflammatory cells and fibrosis were observed in SEMS-inserted surgically-resected specimens. Overall, 84% (21/25) and 60% (15/25) of patients exhibited no change or a decrease in staining category, respectively, for EGFR and VEGF expression after SEMS insertion. A significant decrease in Ki-67 expression was observed in surgically-resected specimens compared with endoscopic biopsy specimens (P < 0.01). The upstream cell cycle inhibitor, p27^kip1, was significantly increased after SEMS insertion (P = 0.049).

CONCLUSIONS

Although the long-term safety of BTS should be determined in a future clinical trial, mechanical compression by SEMS may suppress cancer cell proliferation and this result could provide some insights into the issue.

Endoscopic Stenting for Colorectal Cancer: Lessons Learned From a 15-Year Experience

GOAL

The aim of our prospective study was to analyze the results of endoscopic stenting to treat obstruction due to colorectal cancer and complications after colorectal resection for cancer.

BACKGROUND

Endoscopic stenting for obstructing colorectal cancer has become a common place in clinical practice. However, there is a 2% to 5% risk of bowel perforation, and a percentage of technical failure of 2% to 10%.

MATERIALS AND METHODS

In a 15-year period (August, 1999 to December, 2013), 153 patients with colorectal cancer had endoscopic placement of a self-expandable metal stent for treatment of an obstructing colorectal cancer (133 patients) or for treatment of complications after colorectal resection for cancer (20 patients). They were prospectively evaluated in a database and they form the basis of this report.

RESULTS

There was no case of mortality or major morbidity. Overall technical success was 94.8%. After introducing the use of a pediatric nasogastroscope to pass the obstruction (71 patients), technical success was 100%. Complications in patients in whom the stent was left in place during the follow-up were frequent, requiring a close observation. We had 20 patients with fecal obstruction, 4 cases of stent dislodgment, and 8 cases of obstruction from ingrowth of the tumor. All patients were treated successfully endoscopically.

CONCLUSIONS

Placement of self-expandable metal stents represents a valid technique. A proper training is required.

Outcomes and complications of self-expanding metal stent placement for malignant colonic obstruction in a single-center study

Introduction

Approximately 20% of cases of colorectal cancer are accompanied by acute colonic obstruction. While emergency colonic surgery is associated with high mortality and morbidity rates, placement of a self-expanding metal stent (SEMS) has been suggested as an alternative method. The SEMS placement can serve as either a definitive treatment in palliative cases or a bridge to surgery.

Aim

To summarize the experience of our center in the treatment of malignant colonic obstruction using SEMS placement.

Material and methods

A retrospective review was conducted of all patients who underwent a SEMS placement for colorectal stricture in the study period. The procedures were performed under fluoroscopic guidance with colonoscopic assistance, and uncovered stents were used in all patients.

Results

The study population consisted of 28 patients treated with SEMS placement due to malignant colonic obstruction. The majority of procedures were performed with palliative intent. The overall technical success rate was 96.5%, and clinical success was achieved in all of the successfully placed SEMSs. One fatal complication due to colonic perforation occurred. In the bridge-to-surgery group, all patients experienced tumor resection with no stoma creation.

Conclusions

The SEMS placement is an optimal treatment in the vast majority of acute colonic obstruction cases. Due to the possibility of potentially fatal complications, SEMS procedures should be performed by proficient endoscopists.

Effectiveness and safety of metallic stent for ileocecal obstructive colon cancer: a report of 4 cases

Background and study aims  Self-expandable metallic stents (SEMS) have been widely used for left-sided colorectal obstruction. Few studies on SEMS placement for right-sided colonic obstructions have been reported because stenting in the right colon is technically difficult, particularly in the ileocecal region. We present 4 cases of successful bridge-to-surgery stenting for ileocecal cancer. Using an endoscopic retrograde cholangiopancreatography catheter with a movable tip and a decompression tube was effective for stenting. No adverse events occurred during or after SEMS placement in any of these cases. Short-term stenting for ileocecal cancer seems to be effective and safe.

The role of stents in the management of colorectal complications: a systematic review

BACKGROUND

Complications in colorectal surgery include a wide range of clinical conditions, which increase mortality, morbidity, hospital stay and costs. In some cases, the placement of a self-expanding metal stent may represent a possible therapeutic strategy, avoiding further surgery.

METHODS

In order to verify the feasibility and safety of the technique, we reviewed the medical literature, between January 1997 and 2015, selecting 32 studies. Inclusion criteria were based on Preferred Reporting Items for Systematic reviews and Meta-Analyses recommendations.

RESULTS

The estimated rate of early success was 73.3% (95% CI 66.3-79.3), raising from 25 to 68% in the time frame 1997-2007. The rate of early complications was 31.4% (95% CI 25.3-38.3%), progressively decreasing from 75 to 43% up to 2009. The rate of surgery for acute complication was 9.3% (95% CI 6.0-14.2%), reduced on time course from 25 to 9%. The rate of closure of dehiscence was 74.5% (95% CI 62.8-83.5%), while the rate of long-lasting success was 57.3% (95% CI 50.3-64.0%).

CONCLUSIONS

Endoscopic stenting in the early postoperative management of anastomotic complications after colorectal surgery should be considered in patients with minimal risk for sepsis, as a safe and often effective alternative to surgery. However, in order to establish the safety and efficacy of this technique, prospective studies involving a larger cohort of patients are required.

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 stenting as a bridge to surgery for obstructive colorectal cancer: advantages and disadvantages

PURPOSE

To clarify the advantages and disadvantages of stenting as a bridge to surgery (BTS) by comparing the clinical features and outcomes of patients who underwent BTS with those of patients who underwent emergency surgery (ES).

METHODS

We assessed technical success, clinical success, surgical procedures, stoma formation, complications, clinicopathological features, and Onodera's prognostic nutritional index (OPNI) in patients who underwent BTS and those who underwent ES.

RESULTS

Twenty-six patients underwent stenting, which was successful in 22 (BTS group). The remaining four patients with unsuccessful stenting underwent emergency surgery. A total of 22 patients underwent emergency surgery (ES group). The rates of technical and clinical success were 85.0 and 81.0 %, respectively. The proportion of patients able to be treated by laparoscopic surgery (P = 0.0001) and avoid colostomy (P = 0.0042) was significantly higher in the BTS group. Although the incidence of anastomotic leakage in the two groups was not significantly different, it was significantly reduced by colonoscopic evaluation of obstructive colitis (P = 0.0251). The mean number of harvested lymph nodes (P = 0.0056) and the proportion of D3 lymphadenectomy (P = 0.0241) were significantly greater in the BTS group. Perineural invasion (PNI) was noted in 59.1 and 18.2 % of the BTS group and ES group patients, respectively (P = 0.0053). OPNI and serum albumin decreased significantly after stenting (P = 0.0084).

CONCLUSIONS

The advantages of stenting as a BTS were that it avoided colostomy and allowed for laparoscopic surgery and lymphadenectomy, whereas its disadvantage lay in the decreased PNI and OPNI levels. A larger study including an analysis of prognosis is warranted.

Open surgery versus laparoscopic surgery after stent insertion for obstructive colorectal cancer

PURPOSE

To compare the outcomes of laparoscopic surgery vs. open surgery after insertion of a colonic stent for obstructive colorectal cancer.

METHODS

Between April 2005 and August 2013, 58 patients underwent surgery after the insertion of a colonic stent for obstructive colorectal cancer. We analyzed the outcomes of the patients who underwent laparoscopic surgery vs. those who underwent open surgery.

RESULTS

We compared blood loss, operative time, hospital stay, and complications in 26 patients who underwent laparoscopic surgery and 32 patients who underwent open surgery. Blood loss was significantly less in the laparoscopic surgery group, but operative time was significantly shorter in the open surgery group. The length of hospital stay was shorter in the laparoscopic surgery group than in the open surgery group, but the difference was not significant. There was no significant difference in postoperative surgical complications between the groups.

CONCLUSION

The patients who underwent laparoscopic resection had less blood loss, although no significant difference was found in postoperative morbidity or mortality. Thus, laparoscopic resection after stent insertion is a feasible and safe option for patients with obstructive colorectal cancer.

A Japanese prospective multicenter study of self-expandable metal stent placement for malignant colorectal obstruction: short-term safety and efficacy within 7 days of stent procedure in 513 cases

BACKGROUND

Endoscopic self-expandable metal stent placement has been used as an alternative to surgery for malignant colorectal obstruction; however, factors affecting its clinical outcome are unclear.

OBJECTIVE

To clarify the short-term safety and efficacy of endoscopic self-expandable metal stent placement for malignant colorectal obstruction and to identify factors associated with its clinical and technical failure.

DESIGN

Prospective clinical cohort study.

SETTING

Fourteen academic centers and 32 community hospitals.

PATIENTS

A total of 513 consecutive patients with malignant colorectal obstruction.

INTERVENTION

Endoscopic self-expandable metal stent placement, sharing of stent placement methods among participating facilities.

MAIN OUTCOME MEASUREMENTS

The primary endpoint was clinical success, defined as symptom and radiological finding resolution within 24 hours. Secondary endpoints were technical success and adverse events. The follow-up period was 7 days.

RESULTS

The clinical and technical success rates were 95.5% and 97.9%, respectively. Major adverse events included perforation (2.1%), stent migration (1.0%), and stent occlusion (0.8%). The main causes of perforation were the procedure itself (0.8%) and comorbidities (obstructive colitis and impending perforation) not apparent before stent placement (0.6%). Extrinsic tumor origin was independently associated with the clinical failure after stent placement (odds ratio 4.23; 95% confidence interval, 1.21-14.79; P = .02). Stricture marking trended toward a negative association with technical failure (P = .09).

LIMITATIONS

Noncomparative study.

CONCLUSION

Strict inclusion criteria and stricture marking may improve the technical and clinical success of stent placement.

A Novel Foam Contrast Agent Suitable for Fluoroscopic Interventional Procedure: Comparative Study of Physical Properties and Experimental Intervention in Animal Model

In fluoroscopic contrast study for interventional procedure, liquid contrast agent may be diluted in body fluid, losing its contrast effect. We developed a novel contrast agent of “foam state” to maintain contrast effect for enough time and performed a comparative study of physical properties and its usefulness in experimental intervention in animal model. The mean size of microbubble of foam contrast was 13.8 ± 3.6 µm. The viscosity was 201.0 ± 0.624 cP (centipoise) and the specific gravity was 0.616. The foam decayed slowly and it had 97.5 minutes of half-life. In terms of the sustainability in a slow flow environment, foam contrast washed out much more slowly than a conventional contrast. In experimental colonic stent placement, foam contrast revealed significantly better results than conventional contrast in procedure time, total amount of contrast usage, and the number of injections (p < 0.05). Our foam contrast has high viscosity and low specific gravity and maintains foam state for a sufficient time. Foam contrast with these properties was useful in experimental intervention in animal model. We anticipate that foam contrast may be applied to various kinds of interventional procedures.

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

BACKGROUND/AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Metallic stent insertion with double-balloon endoscopy for malignant afferent loop obstruction

Progress in double-balloon endoscopy (DBE) has allowed for the diagnosis and treatment of disease in the postoperative bowel. For example, a short DBE, which has a 2.8 mm working channel and 152 cm working length, is useful for endoscopic retrograde cholangiopancreatography in bowel disease patients. However, afferent loop and Roux-limb obstruction, though rare, is caused by postoperative recurrence of biliary tract cancer with intractable complications. Most of the clinical findings involving these complications are relatively nonspecific and include abdominal pain, nausea, vomiting, fever, and obstructive jaundice. Treatments by surgery, percutaneous transhepatic biliary drainage, percutaneous enteral stent insertion, and endoscopic therapy have been reported. The general conditions of patients with these complications are poor due to cancer progression; therefore, a less invasive treatment is better. We report on the usefulness of metallic stent insertion using an overtube for afferent loop and Roux-limb obstruction caused by postoperative recurrence of biliary tract cancer under short DBE in two patients with complexly reconstructed intestines.

Palliative self-expandable metal stents for acute malignant colorectal obstruction: clinical outcomes and risk factors for complications

OBJECTIVE

Self-expandable metal stents (SEMSs) have been used as palliative treatment or bridge to surgery for obstructions caused by colorectal cancer (CRC). We assessed the long-term outcomes of palliative SEMSs and evaluated the risk factors influencing complications.

MATERIALS AND METHODS

One hundred and seventy-five patients underwent SEMS placement for acute malignant colorectal obstruction. Of the 72 patients who underwent palliative treatment for primary CRC, 30 patients received chemotherapy (CT) for primary cancer (CT group) and 42 underwent best supportive treatment (BST) without CT (BST group).

RESULTS

There was a significant difference in late migration between the CT group and the BST group (20.0% in CT group, 2.4% in BST group, p = 0.018). Response to CT influenced the rate of late obstruction (0% in disease control, 35.7% in disease progression, p = 0.014). However, late obstruction was not associated with stent properties, such as diameter or type (≤22 mm vs. >22 mm, 13.5% vs. 14.3%, p = 1.00; uncovered stent vs. covered stent, 15.5% vs. 7.1%, p = 0.675) and migration (≤22 mm vs. >22 mm, 16.2% vs. 2.9%, p = 0.108; uncovered stent vs. covered stent, 8.6% vs. 14.3%, p = 0.615) in palliative SEMS.

CONCLUSION

The administration of CT increases the rate of stent migration, and disease control by CT can reduce the risk of obstruction by maintaining the luminal patency of palliative SEMSs.

Uncovered Self-Expanding Metal Stent (SEMS) Four Years After Placement for Long-Term Treatment of a Benign Colonic Obstruction

Self-expanding metal stents (SEMS) have emerged as an alternative to surgery in the treatment of malignant colorectal obstructions. There is limited data about their use for benign colonic obstructions, especially in regards to safety and long-term patency. We present a case in which long-term SEMS placement proved to be a durable option for over 4 years in a patient with a benign colonic stricture.

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.

Systematic review of self-expanding stents in the management of benign colorectal obstruction

AIM

Colorectal obstruction due to benign disease is likely to become more prevalent. Self-expanding stents have been shown to be effective in reducing morbidity and allowing one-stage resection or improved palliation in colorectal cancer. This review assessed the use of self-expanding stents in benign colorectal obstruction.

METHOD

A systematic review was performed using PubMed, Embase and the Cochrane Library. Keywords included: 'benign disease' 'colorectal obstruction', 'stent', 'endoprosthesis' and 'prosthesis' Original articles from all relevant listings were sourced. These were hand searched for further articles of relevance. The main outcome measures assessed were technical and clinical success, perforation, reobstruction and stoma avoidance in the bridge to surgery population.

RESULTS

The search strategy identified 130 articles; the 21 included studies yielded a pooled analysis of 122 patients. Diverticulitis was the predominant aetiology (66/122, 54%). Technical success was achieved in 115/122 (94%) and clinical success in 108/120 (87%) patients. Overall, the perforation rate was 12% (15/122) and the reobstruction rate was 14% (17/122). A stoma was avoided in 48% (23/48) of bridge to surgery patients. Perforation and stoma avoidance in the bridge to surgery group were worse with an aetiology of diverticulitis.

CONCLUSION

Complication rates in stenting for benign colorectal obstruction are higher than for malignant obstruction. On the basis of limited published evidence, stenting cannot be recommended for benign colorectal obstruction.

Local recurrence after stenting for obstructing left-sided colonic cancer

BACKGROUND

Self-expanding metallic stents (SEMS) may be used in acute obstructing left-sided colonic cancers to avoid high-risk emergency surgery. However, oncological safety remains uncertain. This study evaluated the long-term oncological outcome of SEMS as a bridge to elective curative surgery versus emergency resection.

METHODS

A consecutive prospective cohort of patients admitted with obstructing left-sided colonic cancer between 2006 and 2012 was analysed. The decision to stent as a bridge to surgery or to perform emergency surgery was made by the on-call consultant colorectal surgeon in conjunction with a consultant interventional radiologist; when appropriate, they performed the stent procedure together. Primary outcomes were local and distant recurrence, and overall survival. Secondary outcomes were postoperative complications, in-hospital mortality, proportion of procedures undertaken laparoscopically, and anastomosis and stoma rates.

RESULTS

In total, 105 patients with obstructing left-sided colonic cancer were treated with curative intent; 62 were treated with SEMS as a bridge to surgery and 43 had emergency resection. In patients aged 75 years or less, stenting and delayed surgery was associated with a higher local recurrence rate compared with emergency surgery at the end of follow-up (32 versus 8 per cent; P = 0·038). This did not translate into a significant difference in overall survival.

CONCLUSION

SEMS was associated with an increased local recurrence rate.

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.

Self-expanding metallic stents for palliation and as a bridge to minimally invasive surgery in colorectal obstruction

Self-expanding metallic stents are effective for the palliation of malignant obstruction. This study indicates that stents for bowel obstruction may allow for minimally invasive surgical intervention with a shorter hospital stay, lower stoma rate, and earlier chemotherapy administration.

Background and Objectives:

Acute colorectal obstruction is a potentially life-threatening emergency that requires immediate surgical treatment. Emergency procedures had an associated mortality rate of 10% to 30%. This encouraged development of other options, most notably self-expanding metallic stents. The primary endpoint of this study to is to report our group's experience.

Methods:

We performed a retrospective review of 37 patients who underwent self-expanding metallic stent placement for colorectal obstruction between July 2000 and May 2012. Data collected were age, comorbidities, diagnosis, intent of intervention (palliative vs bridge to surgery), complications, and follow-up.

Results:

The study comprised 21 men (56.76%) and 16 women (43.24%), with a mean age of 67 years. The intent of the procedure was definitive treatment in 22 patients (59.46%) and bridge to surgery in 15 (40.54%). The highest technical success rate was at the rectosigmoid junction (100%). The causes of technical failure were inability of the guidewire to traverse the stricture and bowel perforation related to stenting. The mean follow-up period was 9.67 months. Pain and constipation were the most common postprocedure complications.

Discussion:

The use of a self-expanding metallic stent has been shown to be effective for palliation of malignant obstruction. It is associated with a lower incidence of intensive care unit admission, shorter hospital stay, lower stoma rate, and earlier chemotherapy administration. Laparoscopic or robotic surgery can then be performed in an elective setting on a prepared bowel. Therefore the patient benefits from advantages of the combination of 2 minimally invasive procedures in a nonemergent situation. Further large-scale prospective studies are necessary.

Self-expandable metallic stents in patients with stage IV obstructing colorectal cancer

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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.