Colonic stents for malignant bowel obstruction: current status and future prospects

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

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

Management of Malignant Gastric Outlet Obstruction: A Comprehensive Review on the Old, the Classic and the Innovative Approaches

Gastrojejunostomy is the principal method of palliation for unresectable malignant gastric outlet obstructions (GOO). Gastrojejunostomy was traditionally performed as a surgical procedure with an open approach butrecently, notable progress in the development of minimally invasive procedures such as laparoscopic gastrojejunostomies have emerged. Additionally, advancements in endoscopic techniques, including endoscopic stenting (ES) and endoscopic ultrasound-guided gastroenterostomy (EUS-GE), are becoming more prominent. ES involves the placement of self-expandable metal stents (SEMS) to restore luminal patency. ES is commonly the first choice for patients deemed unfit for surgery or at high surgical risk. However, although ES leads to rapid improvement of symptoms, it carries limitations like higher stent dysfunction rates and the need for frequent re-interventions. Recently, EUS-GE has emerged as a potential alternative, combining the minimally invasive nature of the endoscopic approach with the long-lasting effects of a gastrojejunostomy. Having reviewed the advantages and disadvantages of these different techniques, this article aims to provide a comprehensive review regarding the management of unresectable malignant GOO.

Laparoscopic versus open surgery in obstructive colorectal cancer patients following stents placement: a comprehensive meta-analysis of cohort studies

BACKGROUND

Over the past decade, the use of stent placement as a bridge to surgery (BTS) has emerged as an alternative to emergency surgery for patients with (OCRC). However, the optimal surgical approach remains indeterminate. This study seeks to evaluate the safety and feasibility of a combined treatment modality involving stent placement and laparoscopic surgery for OCRC presenting with malignant obstruction.

METHODS

A comprehensive search of PubMed, Cochrane Library, EMBASE, Web of Science, and ClinicalTrials.gov was conducted until June 2023 to identify studies that compared laparoscopic to open surgery in patients with OCBC following stent insertion.

RESULTS

The meta-analysis incorporated 12 cohort studies, encompassing 933 patients. There was no statistically significant difference in the 30-day mortality rates between the two groups (relative risk [RR], 1.09; 95% confidence interval [CI] 0.26 to 4.48; P = 0.95). Compared to the laparoscopic approach group, the open approach group had a higher rate of overall postoperative complications (POCs) (RR 0.52; 95% CI 0.37 to 0.72, P < 0.0001). There was no significant variance in lymph node (LN) dissection number between the groups (mean differences [MD], 1.64; 95% CI - 1.51 to 4.78; P = 0.31). Notably, laparoscopic surgery resulted in less intraoperative blood loss (MD, - 25.84 ml; 95% CI - 52.16 to 0.49; P = 0.05) and a longer operation time (MD, 20.99 mins; 95% CI 2.31 to 39.44; P = 0.03). The laparoscopic approach was associated with a shorter length of hospital stay (LOS) (MD - 3.29 days; 95% CI - 5.27 to 1.31; P = 0.001). Conversely, the open approach group had a higher rate of postoperative surgical site infection (SSI) (RR 0.47; 95% CI 0.23 to 0.96, P = 0.04). Although the number of included studies was insufficient to conduct a meta-analysis, several of them imply that laparoscopic surgery may yield more favorable outcomes in terms of the 3-year overall survival rate (OS), 3-year disease-free survival rate (DFS), 5-year OS, and 5-year DFS when compared to open surgery. It is worth noting that these differences lack statistical significance.

CONCLUSION

In patients with OCRC subjected to stent insertion, laparoscopic surgery arguably presents a modest superiority over open surgery by diminishing the overall postoperative risk and potentially reducing the LOS.

Management of obstructed colorectal carcinoma in an emergency setting: An update

Colorectal carcinoma is common, particularly on the left side. In 20% of patients, obstruction and ileus may be the first clinical manifestations of a carcinoma that has advanced (stage II, III or even IV). Diagnosis is based on clinical presentation, plain abdominal radiogram, computed tomography (CT), CT colonography and positron emission tomography/CT. The best management strategy in terms of short-term operative or interventional and long-term oncological outcomes remains unknown. For the most common left-sided obstruction, the first choice should be either emergency surgery or endoscopic decompression by self-expendable metal stents or tubes. The operative plan should be either one-stage or two-stage resection. One-stage resection with on-table bowel decompression and irrigation can be accompanied or not accompanied by proximal defunctioning stoma (colostomy or ileostomy). Primary anastomosis is more convenient but has increased risks of anastomotic leakage and morbidity. Two-stage resection (Hartmann's procedure) is safer and the most widely used despite temporally affecting quality of life. Damage control surgery in high-risk frail patients is less frequently performed since it can be successfully substituted with endoscopic stenting or tubing. For the less common right-sided obstruction, one-stage surgical resection is more beneficial than endoscopic decompression. The role of minimally invasive surgery (laparoscopic or robotic) is a subject of debate. Emergency laparoscopic-assisted management is advantageous to some extent but requires much expertise due to inherent difficulties in dissecting the distended colon and the risk of rupture and subsequent septic complications. The decompressing stent as a bridge to elective surgery more substantially decreases the risks of morbidity and mortality than emergency surgery for decompression and has equivalent medium-term overall survival and disease-free survival rates. Its combination with neoadjuvant chemotherapy or radiation may have a positive effect on long-term oncological outcomes. Management plans are crucial and must be individualized to better fit each case.

Malignant Acute Colonic Obstruction: Multidisciplinary Approach for Endoscopic Management

Patients presenting with acute colonic obstruction are usually evaluated in the emergency department and multiple specialties are involved in the patients' management. Pre-treatment evaluation is essential in order to establish the correct endoscopic indication for stent implantation. Contrast-enhanced imaging could allow the exclusion of benign causes of colonic obstruction and evaluation of the length of malignant stricture. Endoscopic stenting is the gold standard of treatment for palliative indications whereas there are still concerns about its use as a bridge to surgery. Different meta-analyses showed that stenting as a bridge to surgery improves short-term surgical outcomes but has no role in improving long-term outcomes. Multidisciplinary evaluation is also essential in patients that may be started on or are currently receiving antiangiogenic agents because endoscopic stenting may increase the risk of perforation. Evidence in the literature is weak and based on retrospective data. Here we report on how to correctly evaluate a patient with acute colonic malignant obstruction in collaboration with other essential specialists including a radiologist, surgeon and oncologist, and how to optimize the technique of endoscopic stenting.

Intestinal stent implantation using a water injection device with carbon dioxide and transparent cap: A case report

RATIONALE

Preoperative endoscopic intestinal stent placement can relieve the symptoms of malignant bowel obstruction (MBO) pending investigations, staging, and surgery, but it is a technically challenging procedure. This paper presents a woman with MBO who successfully underwent intestinal stent implantation using a water injection device with carbon dioxide and a transparent cap.

PATIENT CONCERNS

We reported a technique for endoscopic intestinal stent placement. A 60-year-old female patient was admitted for abdominal pain and poor bowel movement for 10 days. Computed tomography at a local hospital suggested local stenosis.

DIAGNOSES

A transparent cap was placed in front of a gastroscope and was used to cross part of the stenotic segment, with water being injected to fill the intestinal cavity continuously. An angiographic catheter was sent along the yellow zebra guidewire passing through the stenotic segment. After exchanging for a colonoscope, a 12-cm intestinal stent was placed along the guidewire.

INTERVENTIONS

The physician used a single-person water injection-assisted colonoscopy technique in combination with a carbon dioxide gas pump to assist with the air insufflation for colonoscope insertion through the lumen and repeatedly injected water solution to ensure a transparent colonoscopic view.

OUTCOMES

No intraoperative or postoperative complications were observed. One week after endoscopic intestinal stent placement, the patient underwent radical left hemicolectomy for colon cancer and release of bowel adhesion. The postoperative pathology revealed adenocarcinoma with perineural invasion. The patient recovered well after surgery.

LESSONS

Single-person intestinal stent implantation using a water injection device with carbon dioxide and a transparent cap can achieve endoscopic intestinal stent placement for MBO.

The clinical outcomes of the radiologic method for self-expandable metal-stent placement in patients with colorectal obstruction: A prospective study

OBJECTIVES

To assess the clinical outcomes of self-expandable metal stent (SEMS) placement for patients with colorectal obstruction.

METHODS

A total of 61 patients underwent SEMS placement using computerized tomography (CT) to confirm malignancy of intrinsic origin and evaluate the exact location, notch, and extent of the disruptive laceration.

RESULTS

The overall technical success rate and clinical success rate of SEMS placement using the radiological method were 59 (96.7%) and 57 (93.4%), respectively. The technical success rate and clinical success rate of SEMS placement in the palliative and bridge to elective surgery (BTS) groups were 35 (97.2%), 24 (96.0%), 33 (91.7%), and 24 (96.0%). The median cumulative primary stent patency duration and patients' survival of SEMS placement was 123 days (95% CI, 65-123 days), and 133 days (95% CI, 72-133 days). The median cumulative primary stent patency duration and patient survival did not differ significantly between the palliative group 119 days; (95% CI, 59-119 days), 128 days; (95% CI, 71-128 days), and the BTS group 120 days; (95% CI, 68-120 days; p = 0.362), 130 days; (95% CI, 78-130 days); p = 0.412).

CONCLUSIONS

The colorectal obstruction had convoluted with curved angulation and located mainly at the rectum, sigmoid, descending colon, and the radiologic method of SEMS placement has more efficacious with a high technical and clinical success rate. However, SEMS placement was highly technical, and clinical success with median stent patency and patient survival did not differ significantly between the palliative group and the BTS group.

An Unusual Complication of Self-Expandable Metal Stent Placement in Malignant Sigmoid Obstruction

Self-expandable metal stent (SEMS) for malignant colorectal obstruction is widely used as a bridge to elective surgery or palliative treatment. However, with the increasing use of SEMS for treatment, complication rates associated with stents have been raised as a concern. We experienced a rare migration-related complication that a stent partially migrated out of the anus with an incarceration. A 62-year-old man was admitted with sigmoid malignant obstruction. Due to multiple metastases, he refused to undergo colostomy, and an uncovered SEMS was placed. Subsequently, he started chemotherapy. Seven months after placement, the stent migrated into the rectum. After unsuccessful attempts to extract the stent, he sought our assistance. We observed that half of the stent was outside the anus, and a 15 mm lump of mucosa was embedded in the proximal end of the stent. After several attempts, we successfully removed the SEMS. Stent incarceration following migration is not a common occurrence, but it serves as a reminder that clinicians need to be more vigilant about complications that may arise after stent implantation. We describe this unusual complication and share our experience about the removal of the stent.

Safety and feasibility of neoadjuvant chemotherapy as a surgical bridge for acute left-sided malignant colorectal obstruction: a retrospective study

BACKGROUND

For colorectal cancer, preoperative (neoadjuvant) chemotherapy is more effective than postoperative chemotherapy because it not only eradicates micrometastases more effectively but also reduces the risk of incomplete intraoperative resection and tumor cell shedding. For the treatment of acute left-sided malignant colorectal obstruction, colorectal stents as well as stoma are being used to relieve the obstructive colorectal cancer, and as a bridge to surgery, allowing easy mobilization and resection of the colon. Neoadjuvant chemotherapy combined with self-expandable metal stents (SEMS) or neoadjuvant chemotherapy combined with decompressing stoma (DS) can be used as a bridge to elective surgery (BTS) as an alternative to emergency surgery in patients with acute left-sided malignant colorectal obstruction, but its benefit is uncertain. The purpose of this study was to evaluate the safety and feasibility of neoadjuvant chemotherapy as a bridge to surgery in the treatment of acute left-sided malignant colorectal obstruction.

METHODS

Data from patients who were admitted with acute left-sided malignant colorectal obstruction between January 2012 and December 2020 were retrospectively reviewed, and patients with gastrointestinal perforation or peritonitis were excluded. We performed one-to-two propensity score matching to compare the stoma requirement, postoperative complications, and other short-term oncological outcomes between the neoadjuvant chemotherapy group and surgery group.

RESULTS

There were no differences in intraoperative blood loss, operative time, one-year postoperative mortality, and postoperative tumor markers between the two groups. The 1-year recurrence-free survival (RFS) rates of neoadjuvant chemotherapy group and surgery group were 96.8 and 91.3% (p = 0.562). The neoadjuvant chemotherapy group was able to reduce stoma rate 1 year after surgery (p = 0.047). Besides, the neoadjuvant group significantly reduced postoperative bowel function time (p < 0.001), postoperative hospital stay (p < 0.001), total hospital stay (p = 0.002), postoperative complications (p = 0.017), reduction in need to stay in the intensive care unit (ICU) (p = 0.042).

CONCLUSIONS

Neoadjuvant chemotherapy as a bridge to elective surgery in patients with acute left-sided malignant colorectal obstruction is safe and has many advantages. Prospective multicenter studies with large samples are needed to further evaluate the feasibility of neoadjuvant chemotherapy.

Endoscopic stent versus diverting stoma as a bridge to surgery for obstructive colorectal cancer: a systematic review and meta-analysis

BACKGROUND

Self-expandable metallic stent (SEMS), an alternative to diverting stoma (DS), has been used as a "bridge to surgery" (BTS) to decompress acute obstruction of colorectal cancer (CRC) for decades. However, whether SEMS is a safe technique for obstruction of CRC without compromising the long-term survival of patients remains unidentified compared to those of DS. The aim of the present study was to elucidate the safety and survival outcomes of SEMS and DS.

METHODS

Embase, PubMed, and Medline were searched for qualified studies published until October, 2020, in which SEMS or DS was performed as a BTS without resection at the same stage. The last search was on December 5th, 2020. The Newcastle-Ottawa scale (NOS) was used to assess the quality of included studies. The major complication rate, mortality, 3-year overall survival (OS), and permanent stoma rate were estimated as outcomes.

RESULTS

The present study was registered on INPLASY (No. 2020100079). Seven eligible studies were included, involving 646 and 712 patients who underwent SEMS and DS treatments, respectively. The Clavien-Dindo I/II grade complication rate was significantly lower in the SEMS group than in the DS group (8.68 vs. 16.85%; RR, 0.59; 95% confidence interval (CI) 0.41-0.84; P = 0.004). The Clavien-Dindo III/IV grade complication rate was comparable in two groups (7.69 vs. 8.79%; RR, 0.82; 95% CI 0.54-1.27; P = 0.37). There were no statistical differences in the short-term mortality (5.16 vs. 4.53%; RR, 1.25; 95% CI 0.75-2.08; P = 0.39), 3-year OS (71.91 vs. 76.60%; RR, 0.93; 95% CI 0.86-1.01; P = 0.10), and permanent stoma rate (22.08 vs. 27.54%; RR, 0.84; 95% CI 0.67-1.06; P = 0.14) between the two groups.

CONCLUSIONS

To some extent, SEMS is a safe BTS technique for acute obstructive CRC, without significant adverse effect on the survival of patients. Given the advantage of minimal invasion, SEMS may be a better alternative to DS for obstructive CRC. However, the conclusions remain to be discussed because of lacking high-quality randomized controlled trails.

Predictors of clinical outcomes of self-expandable metal stent treatment for malignant colorectal obstruction: A Honam Association for the Study of Intestinal Disease (HASID) multicenter study

There has been increased use of self-expandable metal stents (SEMS) in treating malignant colorectal obstruction (MCO). The aim of this study was to investigate factors that are associated with the outcomes of SEMS placement for MCO.Clinical data from patients who underwent SEMS placement for MCO at 6 hospitals in Honam province of South Korea between 2009 and 2018 were reviewed retrospectively. Eight hundred two patients were identified and their data were analyzed. Technical success, clinical success, complications, and predictors of outcome were included as main outcome measures.Technical and clinical success rates were 98.8% (792/802) and 90.1% (723/802), respectively. Complications including stent migration, stent occlusion due to tumor ingrowth and outgrowth, perforation, bacteremia/fever, and bleeding occurred in 123 (15.3%) patients. In multivariate regression analyses, procedure time was significantly associated with the technical success of SEMS placement (P = .001). Longer length of obstruction, the use of covered stent, and longer procedure time were significant independent predictive factors for the clinical success of SEMS placement (odds ratio [OR] 0.974 (95% confidence interval [CI] 0.950-0.990); P = .043, OR 0.255 (95% CI 0.138-0.471); P < .001, and OR 0.957 (95% CI 0.931-0.984); P = .002, respectively). Stage IV colorectal cancer and the use of covered stent were significant independent predictive factors for the development of complications after SEMS placement (OR 2.428 (95% CI 1.407-4.188); P = .001 and OR 3.329 (95% CI 2.060-5.378); P < .001, respectively).Longer length of obstruction, the use of covered stent, and longer procedure time were associated with lower clinical success rates. Having stage IV colorectal cancer and the use of covered stents were associated with an increased risk of complications.

Self-expanding metal stent insertion by colorectal surgeons using a two-person approach colonoscopy without fluoroscopic monitoring in the management of acute colorectal obstruction: a 14-year experience

BACKGROUND

Placement of a self-expanding metal stent (SEMS) in patients presenting with an acute colorectal obstruction (ACO) may obviate emergency surgery (ES), potentially effectively palliating incurable tumors, acting as a bridge to surgery (BTS) in patients with operable or potentially operable tumors and achieving effective decompression of other ACO. We present our experience with SEMS insertion by colorectal surgeons without fluoroscopic monitoring for ACO especially for acute malignant colorectal obstruction (AMCO) for nearly a 14-year period (2007-2020).

AIM

To explore the safety and effectiveness of SEMS insertion in the management of ACO by colorectal surgeons using a two-person approach colonoscopy without fluoroscopic monitoring.

METHODS

We reviewed the medical records of patients retrospectively to identify all patients presenting to our unit with ACO especially with AMCO who had stenting carried out to achieve colonic decompression. All 434 procedures were performed by colorectal surgeons using a two-person approach colonoscopy without fluoroscopic monitoring.

RESULTS

The overall technique success rate and clinic success rate by SEMS insertion were 428/434 (98.6%) and 412/434 (94.9%). The overall incidence of complications by SEMS insertion was 19/434 (4.4%). The complications included clinical perforation (6/434, 1.4%); stent migration (2/434, 0.5%), 1 of which re-stent; stent detachment (fell off) (3/434, 0.7%), none of them with re-stent; stool impaction (6/434, 1.4%), 1 of which re-stent; and abdominal or anal pain (2/434, 0.5%). There was no hemorrhage in any of the 434 patients.

CONCLUSIONS

SEMS insertion is a relatively safe and effective technique for colonic decompression in dealing with ACO as either a BTS or as a palliative measure. It is also a solution to other causes of ACO such as recurrent tumor, benign diseases, or extra-luminal compression. Therefore, ES was largely avoided.

Lumen-apposing metal stent for treatment of malignant biliary obstruction, placed through an uncovered duodenal self-expanding metal stent

The development and refinement of endoscopic stenting techniques in recent years have made endoscopic treatment an important part of palliative care for irresectable malignant disease in the gastrointestinal tract. We present the case of a 82-year-old man with biliary obstruction and duodenal stenosis on the basis of disseminated pancreatic cancer. He was bothered by jaundice and reduced oral intake. This is typically alleviated using stents; however, the placement of a duodenal stent can limit the possibility of subsequent placement of a biliary stent. This therapeutic challenge was solved using a combination of lumen-apposing metal stents (LAMS) and self-expanding uncovered metal stents (SEMS). LAMS is a relatively novel type of stent intended for endoscopic ultrasonography-guided placement. First, we placed a SEMS in the duodenum, a LAMS was subsequently placed through the mesh of the duodenal SEMS, alleviating the biliary system. The patient was able to resume oral intake and his jaundice subsided.

Local drug delivery systems for inflammatory diseases: Status quo, challenges, and opportunities

Inflammation that is not resolved in due course becomes a chronic disease. The treatment of chronic inflammatory diseases involves a long-term use of anti-inflammatory drugs such as corticosteroids and nonsteroidal anti-inflammatory drugs, often accompanied by dose-dependent side effects. Local drug delivery systems have been widely explored to reduce their off-target side effects and the medication frequency, with several products making to the market or in development over the years. However, numerous challenges remain, and drug delivery technology is underutilized in some applications. This review showcases local drug delivery systems in different inflammatory diseases, including the targets well-known to drug delivery scientists (e.g., joints, eyes, and teeth) and other applications with untapped opportunities (e.g., sinus, bladder, and colon). In each section, we start with a brief description of the disease and commonly used therapy, introduce local drug delivery systems currently on the market or in the development stage, focusing on polymeric systems, and discuss the remaining challenges and opportunities in future product development.

Colorectal stent placement assisted by a slim gastroscope: technique and outcomes

BACKGROUND

The distorted anatomy in patients with obstruction renders colon stent placement difficult. Here, we propose two novel techniques for stent implantation.

METHODS

Patients in whom there was difficulty placing the guidewire with the normal method were retrospectively included in our study. All of the patients underwent the technique of combining a slim gastroscope with a normal colonoscope. We assessed the technical success, clinical success, and adverse events associated with self-expanding metal stent placement.

RESULTS

From June 2018 to June 2020, 30.5% of patients with difficult catheterization were included in this study. Finally, stents in 17 of 18 patients (3 rectum, 13 sigmoid colon, 1 descending colon, and 1 hepatic flexure) (94.4%) were placed successfully, assisted by a slim gastroscope with or without radiography, and the obstruction was relieved. Only one remaining patient experienced failure. No intraoperative or 30-day postoperative morbidity or mortality was observed.

CONCLUSION

The present study showed that the stent implantation technique assisted by a slim gastroscope combined with a normal colonoscope was a relatively safe and effective method for abolishing difficult intestinal stenosis. More studies are needed to compare the advantages and disadvantages of this technique with normal endoscopic implantation.

Self-expandable metallic stenting as a bridge to elective surgery versus emergency surgery for acute malignant right-sided colorectal obstruction

Background

The use of a self-expandable metallic stent (SEMS) as a bridge to surgery has increased for patients with obstructing colorectal cancer. However, relatively few reports have compared SEMS as a bridge to elective surgery for acute malignant obstruction of the right-sided colon (MORC) vs. emergency surgery (ES). This study aimed to evaluate the benefits of elective surgery after SEMS placement vs. ES for patients (including stage IV cases) with acute MORC.

Methods

Patients with acute MORC who underwent radical resection for a primary tumour from July 2008 to November 2016 at Zhongshan Hospital of Fudan University were retrospectively enrolled. Postoperative short-term outcomes, progression-free survival (PFS), and overall survival (OS) were compared between the SEMS and ES groups.

Results

In total, 107 patients with acute MORC (35 in the SEMS group and 72 in the ES group) were included for analysis. The Intensive Care Unit admission rate was lower (11.4% vs. 34.7%, P = 0.011), the incidence of complications was reduced (11.4% vs. 29.2%, P = 0.042), and the postoperative length of hospitalisation was significantly shorter (8.23 ± 6.50 vs. 11.18 ± 6.71 days, P = 0.033) for the SEMS group. Survival curves showed no significant difference in PFS (P = 0.506) or OS (P = 0.989) between groups. Also, there was no significant difference in PFS and OS rates between patients with stage II and III colon cancer. After colectomy for synchronous liver metastases among stage IV patients, the hepatectomy rates for the SEMS and ES groups were 85.7% and 14.3%, respectively (P = 0.029). The hazard ratio for colectomy alone vs. combined resection was 3.258 (95% CI 0.858–12.370; P = 0.041).

Conclusion

Stent placement offers significant advantages in terms of short-term outcomes and comparable prognoses for acute MORC patients. For synchronous liver metastases, SEMS placement better prepares the patient for resection of the primary tumour and liver metastasis, which contribute to improved survival.

Comparison of safety between self-expanding metal stents as a bridge to surgery and emergency surgery based on pathology: a meta-analysis

BACKGROUND

To explore the long-term oncological safety of using self-expanding metal stents (SEMS) as a bridge to surgery for acute obstructive colorectal cancer by comparing the pathological results of emergency surgery (ES) with elective surgery after the placement of SEMS.

METHODS

Studies comparing SEMS as a bridge to surgery with emergency surgery for acute obstructive colorectal cancer were retrieved through the databases of Pubmed, Embase, and Cochrane libraries, and a meta-analysis was conducted based on the pathological results of the two treatments. Risk ratios (OR) or mean differences (MD) with 95% confidence intervals (CI) were calculated for the outcomes under random effects model.

RESULTS

A total of 27 studies were included, including 3 randomized controlled studies, 2 prospective studies, and 22 retrospective studies, with a total of 3737 patients. The presence of perineural invasion (RR = 0.58, 95% CI 0.48, 0.71, P < 0.00001), lymphovascular invasion (RR = 0.68, 95% CI 0.47, 0.99, P = 0.004) and vascular invasion (RR = 0.66, 95% CI 0.45, 0.99, P = 0.04) in SEMS group were significantly higher than those in ES group, and there was no significant difference in lymphatic invasion (RR = 0.92, 95% CI 0.77, 1.09, P = 0.33). The number of lymph nodes harvested in SEMS group was significantly higher than that in ES group (MD = - 3.18, 95% CI - 4.47, - 1.90, P < 0.00001). While no significant difference was found in the number of positive lymph nodes (MD = - 0.11, 95% CI - 0.63, 0.42, P = 0.69) and N stage [N0 (RR = 1.03, 95% CI 0.92, 1.15, P = 0.60), N1 (RR = 0.99, 95% CI 0.87, 1.14, P = 0.91), N2 (RR = 0.94, 95% CI 0.77, 1.15, P = 0.53)].

CONCLUSIONS

SEMS implantation in patients with acute malignant obstructive colorectal cancer may lead to an increase in adverse tumor pathological characteristics, and these characteristics are mostly related to the poor prognosis of colorectal cancer. Although the adverse effect of SEMS on long-term survival has not been demonstrated, their adverse effects cannot be ignored. The use of SEMS as the preferred treatment for patients with resectable obstructive colorectal cancer remains to be carefully weighed, especially when patients are young or the surgical risk is not very high.

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.

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.