Urgent Management of Obstructing Colorectal Cancer: Divert, Stent, or Resect?

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.

Efficacy and Feasibility of Complete Mesocolic Excision with Central Vascular Ligation in Complicated Colorectal Cancer

Complete mesocolic excision (CME) with central vascular ligation (CVL) involves sharp dissection through the embryological planes. However, it may be associated with high mortalities and morbidities especially in colorectal emergencies. This study aimed to investigate the outcomes of CME with CVL in complicated colorectal cancers (CRCs). This was a retrospective study of emergency CRC resection in a tertiary center between March 2016 and November 2018. A total of 46 patients, with a mean age of 51 years, underwent an emergency colectomy for cancer (males, 26 [56.5%]; females, 20 [43.5%]). CME with CVL was performed for all patients. The mean operative time and blood loss were 188 min and 397 mL, respectively. Only five (10.8%) patients presented with burst abdomen, whereas only three (6.5%) presented with anastomotic leakage. The mean length of vascular tie was 8.7 cm, and the mean number of harvested lymph nodes (LNs) was 21.2. Emergency CME with CVL is a safe and feasible technique when performed by a colorectal surgeon and will result in obtaining a superior specimen with a large number of LNs.

Structural optimization and in vivo evaluation of a colorectal stent with anti-migration and anti-tumor properties

Clinically, colorectal stents can only palliatively relieve obstruction caused by colorectal cancer (CRC), with a high incidence of stent migration and tumor-related re-obstruction. To overcome these shortcomings, we developed a colorectal stent composed of a structure-optimized nitinol braided stent and a tubular film including an inner layer of poly (ethylene-co-vinyl acetate) (EVA) and a segmental outer layer of EVA with paclitaxel (PTX). The braiding pattern, segment number, and end shape of the stent were optimized based on the mechanical properties, ex vivo and in vivo anti-migration performance, and tissue response of the stent. The optimized nitinol stent had a structure of one middle segment in a hook-pattern and two end segments in a cross-pattern with two studs on each end in a staggered arrangement. Structure-optimized colorectal stents were prepared and evaluated in vivo. PTX released from the stent was mostly distributed in the rabbit rectum in contact with it. The biosafety of the colorectal stent was evaluated using blood tests, biochemical analysis, anatomical observation, and pathological analysis. The anti-tumor effect of the stent was also evaluated by endoscopy, anatomical observation, and pathological and immunohistochemical analyses in rabbits with orthotopic CRC. The results demonstrate that the optimized colorectal stents have effective anti-migration ability and anti-tumor effects with good biosafety. STATEMENT OF SIGNIFICANCE: In order to overcome the most common disadvantages of migration and re-obstruction of colorectal stents clinically, a colorectal stent composed of a structure-optimized nitinol stent and a tubular film including an inner layer of EVA and a segmental outer layer of EVA with PTX was put forward in this study. The optimized nitinol stent had a structure of one middle segment in hook-pattern and two end segments in cross-pattern with two studs on each end in staggered arrangement. The resulting colorectal stent has been proved with good anti-migration ability, anti-tumor effects, and biosafety in vivo, which provides a safe and effective potential treatment modality for patients with colorectal cancer.

Comparison of colonic stenting and stoma creation as palliative treatment for incurable malignant colonic obstruction

BACKGROUND AND AIM

Self-expandable metal stent (SEMS) is a favorable therapeutic option for patients with incurable malignant colonic obstruction (MCO). However, their long-term efficacy and safety compared with those of stoma creation have not been well investigated. This study aimed to compare these long-term outcomes between these two techniques in patients with incurable MCO.

METHODS

This retrospective cohort included patients with incurable MCO with SEMS insertion (n = 105) and stoma creation (n = 97) between January 2009 and December 2019. The primary outcomes were patency after the procedure and 1-year re-intervention rates.

RESULTS

The patency of the SEMS group was lower than that of the stoma group (88.9 vs 93.2% at 6 months, 84.1 vs 90.5% at 12 months, and 65.8 vs 90.5% at 18 months; log-rank test, P = 0.024), but 1-year re-intervention rates were not different between the groups (10 vs 8%, P = 0.558). The median patency durations were 190 days for SEMS insertion and 231 days for stoma creation. Majority (84%) of SEMS patients did not require any re-intervention until death. The early complication rate did not differ between the groups (P = 0.377), but SEMS insertion had fewer late minor complications than stoma creation (5 vs 22%, P = 0.001).

CONCLUSION

SEMS insertion is a safe and effective treatment for patients with incurable MCO. Although SEMS insertion had a lower patency than stoma creation, especially after 1 year, the 1-year re-intervention rates were not different, and SEMS durability was sufficient in most patients.

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.

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.

Management of Malignant Large-Bowel Obstruction

An otherwise healthy 59-year-old man presented to the emergency department with 2 weeks of narrowed stools, 5 days of obstipation, and 1 day of abdominal pain, nausea, and vomiting. Computed tomography revealed an obstructing sigmoid mass without evidence of metastatic disease, and the CEA was 1.2 ng/mL. Flexible sigmoidoscopy confirmed a circumferentially obstructing distal sigmoid neoplasm. Endoscopic stent placement was immediately followed by a firm distended abdomen. An upright radiograph obtained following the procedure demonstrated free intraperitoneal air. An emergent Hartmann procedure was performed for iatrogenic colon perforation in a patient with malignant obstruction and chronic dilation of the proximal colon.