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

Colon stenting as a bridge to surgery in obstructive colorectal cancer management

Colonic stent placement is a commonly used bridging strategy for surgery in patients with obstructive colorectal cancer. The procedure involves the placement of a self-expandable metallic stent (SEMS) across the obstructive lesion to restore intestinal patency and alleviate the symptoms of obstruction. By allowing patients to receive surgery in a planned and staged manner with time for preoperative optimization and bowel preparation, stent placement may reduce the need for emergency surgery, which is associated with higher complication rates and poorer outcomes. This review focuses on the role of colon stenting as a bridge to surgery in the management of obstructive colorectal cancer. SEMS as a bridge to surgery for left-sided colon cancer has been demonstrated to be particularly useful; however, further research is needed for its application in cases of right-sided colon cancer. Colon stent placement also has limitations and potential complications including stent migration, re-obstruction, and perforation. However, the timing of curative surgery after SEMS placement remains inconclusive. Considering the literature to date, performing surgery at an interval of approximately 2 weeks is considered appropriate. Therefore, colonic stent placement may be an effective strategy as a bridge to surgery in patients with obstructive colorectal cancer.

Stage IV Colorectal Cancer at Initial Presentation versus Progression during and after Treatment, Differences in Management: Management Differences for Initial Presentation versus Progression of Disease after Initial Treatment

Stage IV colorectal cancer is a prevalent disease and understanding the appropriate treatment options is important. Medical oncologic treatment remains the mainstay of treatment in cases where curative resection is not possible. Surgical intervention is indicated if the primary tumor and associated metastases are amenable to curative resection or if obstructive, bleeding, or perforative complications arise from the tumor. New endoscopic techniques can provide palliation and benefit for patients who cannot undergo surgery and may speed time to chemotherapy initiation. Recently, immunotherapy has shown promise at managing, controlling, and regressing advanced disease, in some cases converting it to curative with resection. For patients that progress while on treatment, continued medical therapy remains the mainstay of treatment. Further research into the benefits of asymptomatic primary tumor resection without curative intent needs to be performed. Colorectal cancer, and more specifically metastatic colorectal cancer, continues to have improved 1- and 5-year survival rates and likely will continue to do so over the coming months and years.

Best Practices in Esophageal, Gastroduodenal, and Colonic Stenting

Endoscopic stenting is an area of endoscopy that has witnessed noteworthy advancements over the last decade, resulting in evolving clinical practices among gastroenterologists around the world. Indications for endoscopic stenting have progressively expanded, becoming a frequent part of the management algorithm for various benign and malignant conditions of the gastrointestinal tract, from esophagus to rectum. In addition to expanded indications, continuous technological enhancements and development of novel endoscopic stents have resulted in an increased success of these approaches and, in some cases, allowed new applications. This review aimed to summarize best practices in esophageal, gastroduodenal, and colonic stenting.

Delaying surgery for optimization after colonic stent bridging is safe for left-sided malignant large bowel obstruction: Result from 10-year experience and risks factor analysis

AIM

To evaluate the operative and oncological results after colonic stent bridging for left-sided malignant large bowel intestinal obstruction and the risk factors for survival and recurrence after definitive surgery.

METHODOLOGY

Consecutive patients who underwent colonic stenting for malignant left-sided colonic obstruction were included. Patients for palliative stenting or emergency surgery, patient with low rectal tumour or peritoneal metastasis were excluded. The primary outcome was overall survival. Secondary outcomes included stent success rate, stenting related complications, rate of stoma formation and long-term oncological outcome including recurrence rate and recurrence free survival rate.

RESULTS

From June 2011 to June 2021, a total of 222 patients underwent colonic stenting. 112 patients were bridged to surgery after initial stenting, but 7 patients dropped out. Overall survival was 35 months (IQR = 17.75-75.25 months) in the early operation group, 30 months (IQR = 17.5-49.5 months) in the delayed surgery group HR 0.981 (95%CI 0.70-1.395, p = 0.907). Sensitivity analysis performed by excluding stent complications and emergency surgery yielded the same conclusion. Overall stenting complications rate was 17.1%. 11 patients (10.4%) required emergency surgery.

CONCLUSION

There was no difference between early and delayed surgery groups (>4weeks) in the overall survival and recurrence in patients who had stent-bridge to surgery for malignant left colonic obstruction. It is safe to defer definitive surgery to optimize patients and allow better recovery from initial obstruction after colonic stenting before definitive surgery without adversely affecting the oncological outcomes.

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.

Detection methods of synchronous colorectal lesions in proximal colon for patients with obstructive colorectal cancer: a literature review

INTRODUCTION

Colorectal cancer holds a high morbidity and mortality rate. As a common method for colorectal cancer detection, colonoscopy has difficulty in passing through the malignant stenosis in patients with obstructive colorectal cancer, which results in incomplete detection and missed diagnosis. The missed synchronous lesions increase the risk of metachronous cancer. Therefore, detecting proximal synchronous lesions in patients with obstructive colorectal cancer should be appreciated before operation.

AREA COVERED

This review evaluates related literature, aiming at providing clinicians with more ideas and attention for detecting proximal synchronous lesions in patients with obstructive colorectal cancer.

EXPERT OPINION

In patients with obstructive colorectal cancer, missed diagnosis of lesions proximal to the obstruction may lead to metachronous colorectal cancer. Except for preoperative colonoscopy which is difficult to pass through malignant stenosis, other methods that can evaluate proximal colon segment are critical. This article introduced several preoperative, intraoperative and postoperative measures for synchronous lesions detection. The choice of methods should base on patients' conditions, aiming at a high diagnostic yield and low risk. Early detection and resection of synchronous lesions in the proximal section of malignant obstruction are expected to minimize the risk of metachronous colorectal cancer and even effect follow-up treatment strategy, which deserves the attention of clinicians.

Localized Photothermal Ablation Therapy of Obstructive Rectal Cancer Using a Nanofunctionalized Stent in a Mouse Model

The self-expanding metal stent (SEMS) is a versatile, palliative treatment method for unresectable, malignant, non-vascular strictures. Colorectal cancer (CRC) is one of the candidates for the application of the SEMS, in combination with the photothermal ablation (PTA) technique that enhances its therapeutic efficacy. The objective of this study was to investigate the efficacy of stent-mediated PTA therapy in an endoscopy-guided, orthotopic rectal cancer model. A total of 30 of 40 mice with the tumor size of grade 4 were included and were divided into three groups of 10 mice each. Group A underwent a gold nanoparticle (AuNP)-coated SEMS but no near-infrared (NIR) irradiation, group B received an uncoated control SEMS with NIR irradiation, and group C received a AuNP-coated SEMS and NIR irradiation together. Colonoscopy and in vivo imaging, immunohistochemical analysis, and quantitative reverse-transcription polymerase chain reaction of major tumor markers were performed. Stent placement and PTA were technically successful using colonoscopy. The tumor grade reduction after PTA is significant in group C, compared with groups A or B (p < 0.001). Molecular analysis validated this observation with a significantly reduced Mapk1 proliferation marker or increased Jnk expression. Histological analysis confirmed the localized PTA therapy using AuNP-coated SEMS profoundly ablated tumor outgrowth through the stent. Our results indicate that this novel strategy of localized PTA therapy could be a promising option for palliative treatment of CRC and to support prolonged stent patency with a decreased tumor volume.

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.

[Palliative endoscopy]

Endoscopy is the leading method in the diagnostics of gastrointestinal malignancies. With the increasing incidences of various tumor entities, a palliative treatment situation is already present in many patients despite an increasing number of screening strategies. Palliative endoscopy can make an essential contribution to alleviation of tumor-related symptoms, such as dysphagia, malnutrition, cholestasis, ileus and pain. Various approaches can be offered to safeguard the nutrition, e.g. percutaneous endoscopic gastrostomy (PEG) and percutaneous endoscopic jejunostomy (PEJ), for maintenance of the gastrointestinal passage (stents) and secretion drainage or to drain congested hollow organs. Furthermore, in cases of inaccessibility or impassability of stenoses due to tumors, endosonographically assisted punctures offer the possibility to guarantee new drainage options or continuities by stent placement. In all interventions possible contraindications and complications must be taken into account.

Endoscopic treatment of Crohn-related strictures with a self-expandable stent compared with balloon dilation: a prospective, randomised, controlled study

OBJECTIVE

Fibrotic strictures in the gastrointestinal tract are frequent in Crohn's disease. Endoscopic dilation is a standard treatment. However, recurrence is common after dilation and there are complications such as bleeding or perforation. Endoscopic treatment using self-expandable metal stents has shown diverging results. The aim of this study was to evaluate the outcome of endoscopic treatment with a self-expandable stent in ileocecal Crohn's disease.

DESIGN/METHOD

Patients with Crohn's disease and a symptomatic ileocecal stricture were eligible for prospective, consecutive inclusion in a single-centre setting. Patients were randomised to treatment with either 18 mm balloon dilatation (Group_DIL) or stenting (Group_STENT) using a 20 mm diameter, partially covered Hanarostent NCN. Patients were followed for a minimum of 24 months postendoscopy. Outcomes were technical success, adverse events and clinical success (defined as no need for repeated interventions).

RESULTS

Thirteen patients (Group_DIL n=6; Group_STENT=7) were included with twelve patients (Group_DIL n=5; Group_STENT=7) being eligible for complete follow-up. Technical success was achieved in all cases. Adverse events were border-line significantly more common in the Group_STENT: 4/7 (57%) (pain: n=3; pain and rectal bleeding: n=1) compared with the Group_DIL: 0/5 (0%), p=0.08, which resulted in preterm termination of the study. The clinical success rate was Group_STENT: 6/7 (86%) vs Group_DIL: 1/5 (20%), p=0.07.

CONCLUSION

Patients with strictures related to Crohn's disease may benefit from treatment with self-expandable metal stents rather than dilatation. However, there seems to be an increased risk for patient pain after stenting, which has to be considered and handled.

TRAIL REGISTRATION NUMBER

The study was registered at Clinical Trials (NCT04718493).

Covered Metal Stent after Dysfunction of Uncovered Stents for Palliation of Gastrointestinal Malignant Obstruction

Background

Self-expanding metal stents (SEMS) have been used for the palliative treatment of malignant gastrointestinal tract obstruction. However, restenosis or incomplete expansion of a first stent is a frequent complication, and the effectiveness of reintervention with placement of a second stent is still controversial.

Objective

To evaluate the clinical outcomes of covered SEMS (cSEMS) placement after dysfunction of uncovered SEMS (uSEMS) by the stent-in-stent technique.

Patients and Methods

We retrospectively studied a consecutive series of patients receiving palliative treatment for malignant gastrointestinal obstruction with cSEMS placement after uSEMS dysfunction in a tertiary center from January 2013 to August 2018. Technical and clinical success, time of patency, and adverse events were analyzed.

Results

Twelve patients were included; their mean age was 60 ± 9 years. Eleven patients had gastric outlet obstruction, and 1 patient had compression of the transverse colon due to gastric neoplasia. In 5 cases, there was absence of early clinical success with uSEMS and stent dysfunction in 7 cases (median patency time: 81 days). There was 100% technical success and 91.7% clinical success after cSEMS placement. There were no adverse events nor need for reintervention. The median patency time after placement of both stents was 163 days (vs. 71 days with the initial stent).

Conclusion

cSEMS placement after uSEMS dysfunction is technically feasible and a clinically effective treatment for patients with recurrent malignant gastrointestinal obstruction, with good stent patency in the medium/long term. This approach seems to be safe and without increase in adverse effects.

Obstructing Left-Sided Colonic Cancer: Is Endoscopic Stenting a Bridge to Surgery or a Bridge to Nowhere?

For the 8-29% colorectal cancers that initially manifest with obstruction, emergency surgery (ES) was traditionally considered the only available therapy, despite high morbidity and mortality rates and the need for colostomy creation. More recently, malignant obstruction of the left colon can be temporized by endoscopic placement of a self-expanding metallic stent (SEMS), used as bridge to surgery (BTS), facilitating a laparoscopic approach and increasing the likelihood that a primary anastomosis instead of stoma would be used. Despite these attractive outcomes, the superiority of the BTS approach is not clearly established. Few authors have stressed the potential cancer risk associated with perforations that may occur during endoscopic stent placement, facilitating neoplastic spread and negatively impacting prognosis. For this reason, the current literature focuses on long-term oncologic outcomes such as disease-free survival, overall survival and recurrence rate that do seem not to differ between the ES and BTS approaches. This lack of consensus has spawned differing and sometimes discordant guidelines worldwide. In conclusion, 20 years after the first description of a colonic stent as BTS, the debate is still open, but the growing number of articles about the use of SEMS as a BTS signifies a great interest in the topic. We hope that these data will finally converge on a single set of recommendations supporting a management strategy with well-demonstrated superiority.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Bridge to surgery using a self-expandable metallic stent for stages II-III obstructive colorectal cancer

BACKGROUND

Bridge to surgery (BTS) using a self-expandable metallic stent (SEMS) for the treatment of obstructive colorectal cancer improves the patient's quality of life. This study aimed to examine prognostic factors of obstructive colorectal cancer.

METHODS

We analyzed stage II-III resectable colon cancer cases (Cur A) retrospectively registered between January 2005 and December 2017. Overall, 117 patients with Cur A obstructive colorectal cancer were evaluated: 67 of them underwent emergency surgery (ES Group) and 50 of them after BTS with SEMS placement (BTS group). We compared surgical results and prognoses between the two groups.

RESULTS

A total of 50 patients underwent endoscopic SEMS placement, which technical success of 96% and morbidity rate of 18%. Primary anastomosis rates were 77.6% in ES and 95.7% in BTS (p <  0.001); postoperative complication, 46.3% in ES and 10.5% in BTS (p <  0.001); pathological findings of lymphatic invasion, 66.7% in ES and 100% in BTS (p <  0.001); venous invasion were 66.8% in ES and 92% in BTS (p = 0.04); and recurrence of 25.4% in ES and 39.1% in BTS. The 3-year overall survival was significantly different between two groups (ES, 86.8%:BTS, 58.8%), BTS is worse than ES (log-rank test; p <  0.001). Venous invasion independently predicted worsened recurrence-free and overall survival.

CONCLUSIONS

The vascular invasiveness was correlated with tumor progression after SEMS placement, and the survival rate was lower in BTS. SEMS potentially worsens prognostic outcomes in stage II-III obstructive colorectal cancer.

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.

Endoscopic Self-Expandable Metallic Stent Insertion without Fluoroscopic Guidance Is Feasible and Safe for Acute Colonic Obstruction Caused by Colorectal Cancer

Aims

Endoscopic self-expandable metallic stent (SEMS) insertion for acute colonic obstruction caused by colorectal cancer (CRC) is always performed under fluoroscopic guidance. This study evaluated the feasibility and safety of an endoscopic stenting procedure without fluoroscopic guidance.

Methods

A total of 36 patients with an acute colonic obstruction caused by CRC underwent endoscopic SEMS insertion using a colonoscope without fluoroscopic guidance, followed by analyses of the technical and clinical success and short-term complications.

Results

Total technical success rate and clinical success rate were 91.7% and 86.1%, respectively. The mean procedure time was 21.2 ± 10.3 minutes. There was no stent dislodgement. One case of hematochezia and two cases of tenesmus occurred in patients with left-sided complete obstructions. No other short-term complications occurred. Procedure time, technical success, and clinical success rate were 16.3 ± 9.4 minutes, 93.1%, and 89.6% for left-sided obstructions, respectively, and were 26.8 ± 10.7 minutes, 85.7%, and 71.4% for right-sided obstructions, respectively. For complete obstructions, procedure time, technical success, and clinical success rate were 22.5 ± 8.9 minutes, 90%, and 83.3%, respectively. In the incomplete cases, procedure time, technical success, and clinical success were 13.5 ± 6.7 minutes, 100%, and 100%, respectively. Technical success, clinical success, and short-term complications were not differed between lesion locations and degrees.

Conclusions

This simple technique is feasible and safe for palliation of acute colonic obstruction caused by CRC.

Endoscopic Management of Malignant Colonic Obstruction

Advanced colorectal cancer can cause acute colonic obstruction, which is a life-threatening condition that requires emergency bowel decompression. Malignant colonic obstruction has traditionally been treated using emergency surgery, including primary resection or stoma formation. However, relatively high rates of complications, such as anastomosis site leakage, have been considered as major concerns for emergency surgery. Endoscopic management of malignant colonic obstruction using a self-expandable metal stent (SEMS) was introduced 20 years ago and it has been used as a first-line palliative treatment. However, endoscopic treatment of malignant colonic obstruction using SEMSs as a bridge to surgery remains controversial owing to short-term complications and longterm oncological outcomes. In this review, the current status of and recommendations for endoscopic management using SEMSs for malignant colonic obstruction will be discussed.

Endoscopic stenting in colorectal cancer

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

Endoscopic Management of Benign Colonic Obstruction and Pseudo-Obstruction

There are a variety of causes of intestinal obstruction, with the most common cause being malignant diseases; however, volvulus, inflammatory bowel disease or diverticulitis, radiation injury, ischemia, and pseudo-obstruction can also cause colonic obstruction. These are benign conditions; however, delayed diagnosis of acute intestinal obstruction owing to these causes can cause critical complications, such as perforation. Therefore, high levels of clinical suspicion and appropriate treatment are crucial. There are variable treatment options for colonic obstruction, and endoscopic treatment is known to be a less invasive and an effective option for such. In this article, the authors review the causes of benign colonic obstruction and pseudo-obstruction and the role of endoscopy in treating them.

Endoscopic stenting for palliation of intra-abdominal gastrointestinal malignant obstruction: predictive factors for clinical success

BACKGROUND

Endoscopic stenting proved to be a safe alternative to surgery for malignant intra-abdominal gastrointestinal obstruction. Although high technical success rates have been reported, some patients do not experience relief in symptoms.

AIM

This study aimed to analyse the factors predicting the effectiveness of stent placement in patients with gastrointestinal obstruction.

PATIENTS AND METHODS

A retrospective study was carried out including 160 patients who underwent palliative stenting for intra-abdominal obstruction in a tertiary centre from December 2012 to July 2017. Technical and clinical success, stent dysfunction and adverse events were analysed.

RESULTS

The rate of technical success was 98%. The rate of early clinical success was 69 and 81% in upper and lower gastrointestinal obstructions, respectively (P=0.107). In the upper tract, obstruction caused by carcinomatosis was the only independent factor predicting early and late clinical failure [odds ratio (OR): 9.7, 95% confidence interval (CI): 2.5-38.4, P=0.001 and OR: 7.6, 95% CI: 1.8-31.9, P=0.006, respectively]. In the colon, Eastern Cooperative Oncology Group score of at least 3 was an independent factor for early clinical failure (OR: 29.8, 95% CI: 1.9-464.9, P=0.002) and obstruction caused by carcinomatosis was an independent factor for late clinical failure (OR: 14.4, 95% CI: 1.7-119.6, P=0.013). Perforation occurred in 4 patients (2.5%) and stent dysfunction occurred in 15% of patients (4% stent migration; 9% restenosis). Carcinomatosis was a risk factor for perforation (P=0.039) and migration was higher with shorter 6 cm stents (P=0.044).

CONCLUSION

Stents are effective and safe for palliation of intra-abdominal obstruction. Carcinomatosis predicts an unfavourable clinical outcome. Palliative stenting as an option should be weighed carefully in these patients.

Sulodexide for Secondary Prevention of Recurrent Venous Thromboembolism: A Systematic Review and Meta-Analysis

Background: Patients with venous thromboembolism have high risk of recurrence after discontinuation of anticoagulant treatment. Extended anticoagulation, such as traditional anticoagulants, can reduce the risk of recurrence but is associated with increased risk of hemorrhage. Sulodexide is a natural glycosaminoglycan mixture which can prevent recurrent venous thromboembolism. However, its clinical efficiency and safety still remain controversial. Methods: A systematic search in Medline, EMBASE, Cochrane Library, Web of Science and bibliographies of retrieved articles was performed. Prospective controlled studies reporting the efficacy and safety of sulodexide on the secondary prevention of recurrent venous thromboembolism were included. Two reviewers independently extracted the following data: first author, year of publication, study design, characteristics of patients, data of interventions, doses of sulodexide, overall duration of drug administration, time of follow-up, efficacy and safety outcomes, adverse effects, and the quality of the included studies. The primary efficacy outcomes were recurrent deep vein thrombosis (DVT) or pulmonary embolism. The secondary efficacy outcomes included distal or superficial vein thrombosis and nonfatal or fatal myocardial infarction, stroke, and acute ischemia of the lower limbs. Safety outcome was possible hemorrhagic episodes. Results: Four studies involving 1,461 patients were enrolled in this study. Meta-analysis showed that sulodexide significantly reduced the recurrent venous thromboembolism [RR 0.51, 95 % CI [0.35, 0.74], P = 0.0004] and superficial vein thrombosis in the sulodexide group [RR 0.41, 95% CI [0.22, 0.76], P = 0.005]. The safety of sulodexide was also reliable. The rate of bleeding was 0.28% in the sulodexide group and 1.60% in the control group, and design of study did not influence these results. Conclusions: Sulodexide could significantly reduce the recurrence of VTE after discontinuation of anticoagulation treatment as compared with placebo.

Clinical Outcomes of Self-Expandable Metal Stents for Malignant Rectal Obstruction

BACKGROUND

Self-expandable metal stents are widely used to treat malignant colorectal obstruction. However, data on clinical outcomes of stent placement for rectal obstruction specifically are lacking.

OBJECTIVE

We aimed to investigate the clinical outcomes of self-expandable metal stents in malignant rectal obstruction in comparison with those in left colonic obstruction and to identify factors associated with clinical failure and complication.

DESIGN

This was a retrospective study.

SETTINGS

The study was conducted at a tertiary care center.

PATIENTS

Between January 2005 and December 2013, medical charts of patients who underwent stent placement for malignant rectal or left colonic obstruction were reviewed retrospectively.

INTERVENTION

Study intervention included self-expandable metal stent placement.

MAIN OUTCOME MEASURES

Technical success, clinical success, and complications were measured.

RESULTS

Technical success rates for the 2 study groups (rectum vs left colon, 93.5% vs 93.1%; p = 0.86) did not differ significantly; however, the clinical success rate was lower in patients with rectal obstruction (85.4% vs 92.1%; p = 0.02). In addition, the complication rate was higher in patients with rectal obstruction (37.4% vs 25.1%; p = 0.01). Patients with rectal obstruction showed higher rates of obstruction because of extracolonic malignancy (33.8% vs 15.8%; p < 0.001) and stent use for palliation (78.6% vs 56.3%; p < 0.001). Multivariate analysis indicated obstruction attributed to extracolonic malignancy and covered stent usage to be independent risk factors for clinical failure. Factors predictive of complications in the palliative group were total obstruction, obstruction because of extracolonic malignancy, and covered stent usage.

LIMITATIONS

This was a retrospective, single-center study.

CONCLUSIONS

The efficacy and safety of stent placement for malignant rectal obstruction were comparable with those for left colonic obstruction. However, obstruction attributed to extracolonic malignancy, use of covered stents, and total obstruction negatively impacted clinical outcomes of self-expandable metal stent placement and must be considered by endoscopists. See Video Abstract at http://links.lww.com/DCR/A417.

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.

Methodological overview of systematic reviews to establish the evidence base for emergency general surgery

BACKGROUND

The evidence for treatment decision-making in emergency general surgery has not been summarized previously. The aim of this overview was to review the quantity and quality of systematic review evidence for the most common emergency surgical conditions.

METHODS

Systematic reviews of the most common conditions requiring unplanned admission and treatment managed by general surgeons were eligible for inclusion. The Centre for Reviews and Dissemination databases were searched to April 2014. The number and type (randomized or non-randomized) of included studies and patients were extracted and summarized. The total number of unique studies was recorded for each condition. The nature of the interventions (surgical, non-surgical invasive or non-invasive) was documented. The quality of reviews was assessed using the AMSTAR checklist.

RESULTS

The 106 included reviews focused mainly on bowel conditions (42), appendicitis (40) and gallstone disease (17). Fifty-one (48·1 per cent) included RCTs alone, 79 (74·5 per cent) included at least one RCT and 25 (23·6 per cent) summarized non-randomized evidence alone. Reviews included 727 unique studies, of which 30·3 per cent were RCTs. Sixty-five reviews compared different types of surgical intervention and 27 summarized trials of surgical versus non-surgical interventions. Fifty-seven reviews (53·8 per cent) were rated as low risk of bias.

CONCLUSION

This overview of reviews highlights the need for more and better research in this field.

Role of colonic stents in the management of colorectal cancers

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

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.

Colorectal Stents: Current Status

A self-expandable metal stent (SEMS) is an effective and safe method for the decompression of colon obstruction. Based on recent evidence, colorectal SEMS is now recommended for the palliation of patients with colonic obstruction from incurable colorectal cancer or extracolonic malignancy and also as a bridge to surgery in those who are a high surgical risk. Prophylactic SEMS insertion in patients with no obstruction symptoms is not recommended. Most colorectal SEMS are inserted endoscopically under fluoroscopic guidance. The technical and clinical success rates of colorectal SEMS are high, and the complication rate is acceptable. Advances in this technology will make the insertion of colorectal SEMS better and may expand the indications of colorectal SEMS in the future.

Role of stenting in gastrointestinal benign and malignant diseases

Advances in stents design have led to a substantial increase in the use of stents for a variety of digestive diseases. Initially developed as a non-surgical treatment for palliation of esophageal cancer, the stents now have an emerging role in the management of malignant and benign conditions as well as in all segments of the gastrointestinal tract. In this review, relevant literature search and expert opinions have been used to evaluate the key-role of stenting in gastrointestinal benign and malignant diseases.

What is the necessity of endoscopist for successful endoscopic stenting in patients with malignant colorectal obstruction?

BACKGROUND AND AIM

Recently, self-expandable metal stents (SEMSs) have been widely used as an initial therapy for relieving malignant colorectal obstructions. However, several factors, including the endoscopist's experience, affect the clinical outcome of SEMSs. The aim of this study was to define the adequate level of experience necessary to perform endoscopic stenting effectively and safely and to identify technical factors for successful stenting.

METHODS

Between March 2009 and June 2012, 160 patients underwent SEMS placement for malignant colorectal obstruction with the intent of palliation or as a bridge to surgery by a single endoscopist who experienced colonoscopy and endoscopic retrograde cholangiopancreatography.

RESULTS

The overall technical and clinical success rates were 86.9 and 86.4%, respectively, and 18 complications (11.3%) were observed. There were no differences in any of the clinical outcomes between the consecutive blocks; however, the procedure time decreased significantly after the first 30 procedures (17.4, 16.9, 13.5, and 12.8 min; P = 0.044). American Society of Anesthesiologists (ASA) class, history of a previous operation, proximal colon obstruction, obstruction caused by an extracolonic malignancy, and palliative SEMS placement were associated with technical failure.

CONCLUSIONS

An endoscopist who experiences a colonoscopy and fluoroscopy performs SEMS placement successfully regardless of the level of experience. After the first 30 procedures, a SEMS insertion could be safely and effectively performed with short procedure time in patients with malignant colorectal obstruction.

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.

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.

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.

SEMS vs cSEMS in duodenal and small bowel obstruction: High risk of migration in the covered stent group

AIM: To compare clinical success and complications of uncovered self-expanding metal stents (SEMS) vs covered SEMS (cSEMS) in obstruction of the small bowel.

METHODS: Technical success, complications and outcome of endoscopic SEMS or cSEMS placement in tumor related obstruction of the duodenum or jejunum were retrospectively assessed. The primary end points were rates of stent migration and overgrowth. Secondary end points were the effect of concomitant biliary drainage on migration rate and overall survival. The data was analyzed according to the Strengthening the Reporting of Observational Studies in Epidemiology guidelines.

RESULTS: Thirty-two SEMS were implanted in 20 patients. In all patients, endoscopic stent implantation was successful. Stent migration was observed in 9 of 16 cSEMS (56%) in comparison to 0/16 SEMS (0%) implantations (P = 0.002). Stent overgrowth did not significantly differ between the two stent types (SEMS: 3/16, 19%; cSEMS: 2/16, 13%). One cSEMS dislodged and had to be recovered from the jejunum by way of laparotomy. Time until migration between SEMS and cSEMS in patients with and without concomitant biliary stents did not significantly differ (HR = 1.530, 95%CI 0.731-6.306; P = 0.556). The mean follow-up was 57 ± 71 d (range: 1-275 d).

CONCLUSION: SEMS and cSEMS placement is safe in small bowel tumor obstruction. However, cSEMS is accompanied with a high rate of migration in comparison to uncovered SEMS.

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.