Risk factors that influenced clinical failure were carcinomatosis, obstruction attributed to ECM, palliative SEMS placement, covered stent insertion and rectal obstruction
The efficacy and safety of self-expandable metal stents (SEMS) placement for malignant rectal obstruction are comparable to those for left colonic obstruction, according to researchers from Yonsei University College of Medicine and Seoul National University College of Medicine, Seoul, South Korea. However, the authors of the paper, ‘Clinical Outcomes of Self-Expandable Metal Stents for Malignant Rectal Obstruction’, published in the journal, Diseases of the Colon and Rectum, noted that obstruction because of extracolonic malignancy (ECM) can negatively impact clinical outcomes and therefore alternative surgical interventions should be considered.
The paper’s authors write that although SEMS are widely used to treat malignant colorectal obstruction, data on clinical outcomes of stent placement for rectal obstruction specifically are lacking. Therefore, they sought to investigate the clinical outcomes of SEMS in malignant rectal obstruction in comparison with those in left colonic obstruction and to identify factors associated with clinical failure and complication.
In this retrospective, single centre study, the records of 573 patients (men=340) who underwent stent placement for malignant rectal or left colonic obstruction between January 2005 and December 2013 were reviewed retrospectively. A total of 154 patients (26.9%) underwent SEMS placement for rectal obstruction and 419 (73.1%) for left colonic obstruction. In 455 patients (79.4%), obstructions were caused by primary colorectal cancer and in 118 (20.6%) by an ECM.
SEMS placement was performed for palliation in 357 patients (62.3%) and as a bridge to surgery in 216 (37.7%). A total of 193 patients (33.7%) had peritoneal seeding, 189 (33.0%) experienced total obstruction and 395 (72.5%) had uncovered stents. In patients with rectal (vs left colonic) obstruction, rates of obstruction attributed to ECM (33.8% vs 15.8%; p<0.001) and SEMS use for palliation (78.6% vs 56.3%; p<0.001) were significantly higher.
SEMSs were placed successfully in 534 (93.2%) of 573 patients with clinical success achieved in 482 patients (90.3%). Technical success rates of the two study groups (rectum vs left colon, 93.5% vs 93.1%; p=0.86) did not differ significantly, but the clinical success rate was lower in patients with rectal obstruction (85.4% vs 92.1%; p=0.02).
In total, 136 patients experienced complications (28.2%; early=45; late=99), the most common complication was re-obstruction (n=103 patients; 21.4%), followed by stent migration (n=22; 4.6%), perforation (n=17; 3.5%), bleeding (n=13; 2.7%), anal pain (n=11; 2.2%) and incontinence (n=1;0.2%). The authors reported that the complication rate was higher in patients with rectal obstruction (37.4% vs 25.1%; p=0.01).
Risk factors that influenced clinical failure were carcinomatosis (p<0.001), obstruction attributed to ECM (p<0.001), palliative SEMS placement (p<0.001), covered stent insertion (p=0.01) and rectal obstruction (p=0.02). In multivariate analysis, the researchers identified obstruction attributed to ECM (p<0.001) and covered stent usage (p=0.005) as independent risk factors for clinical failure.
“The efficacy and safety of SEMS placement for malignant rectal obstruction were comparable to those for left colonic obstruction. Moreover, in contrast to current clinical guidelines, SEMS insertion could be considered as an option for the management of patients with lower rectal cancer (≤5 cm from anal verge) who had relatively limited life expectancy or surgically unfit condition,” the authors concluded. “However, because obstruction attributed to ECM, use of covered stents, and total obstruction, rather than rectal obstruction itself, negatively impact clinical outcomes of SEMS placement, these factors must be kept in mind by endoscopists when deciding on appropriate treatments and might be potential indications for alternative surgical intervention.”
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