Reevaluation of Self-Expanding Metal Stents as a Bridge to Surgery for Acute Left-Sided Malignant Colonic Obstruction: Six Years Experience

Manufacturing, Processing, and Characterization of Self-Expanding Metallic Stents: A Comprehensive Review

This paper aims to review the State of the Art in metal self-expanding stents made from nitinol (NiTi), showing shape memory and superelastic behaviors, to identify the challenges and the opportunities for improving patient outcomes. A significant contribution of this paper is its extensive coverage of multidisciplinary aspects, including design, simulation, materials development, manufacturing, bio/hemocompatibility, biomechanics, biomimicry, patency, and testing methodologies. Additionally, the paper offers in-depth insights into the latest practices and emerging trends, with a special emphasis on the transformative potential of additive manufacturing techniques in the development of metal stents. By consolidating existing knowledge and highlighting areas for future innovation, this review provides a valuable roadmap for advancing nitinol stents.

Which treatment strategy is optimal for acute left-sided malignant colonic obstruction? A Bayesian meta-analysis

PURPOSE

This study aimed to determine the best treatment for acute left-sided malignant colonic obstruction (ALMCO) among emergency surgery (ES), self-expanding metallic stent (SEMS), transanal drainage tube (TD), and decompressive stoma (DS).

METHOD

Articles that compared two or more treatments of ALMCO were searched from PubMed, Cochrane Library, and Embase. Network meta-analyses were performed to calculate the outcomes of primary anastomosis, stoma creation, morbidity, mortality, and 5-year survival.

RESULTS

Fifty-one articles met inclusion criteria. TD was the optimal treatment in performing primary anastomosis [probability of ranking first (Pro-1) 0.96], while ES was the worst [probability of ranking fourth (Pro-4) 0.99]. More permanent stoma was formed in ES and TD groups than in SEMS and DS groups [OR (95%CI): TD vs SEMS: 4.12 (1.89, 9.45); TD vs DS: 3.39 (1.46, 8.75); ES vs DS: 2.55 (1.73, 4.17); SEMS vs ES: 0.33 (0.24, 0.42)]. More morbidity occurred in ES group than in SEMS group [OR (95%CI): ES vs SEMS: 1.44 (1.14, 1.82)]. Besides, SEMS was ranked first in avoiding infection (Pro-4 0.95). For in-hospital mortality, ES was ranked first (Pro-1 0.93). TD was ranked first in recurrence (Pro-1 0.97) and metastasis (Pro-1 0.98). There was no discrepancy in 5-year overall and disease-free survival among all strategies.

CONCLUSION

SEMS as a bridge to surgery reduces stoma formation, and morbidity especially the infection rate with relatively great oncological outcomes. Therefore, SEMS should be recommended first for ALMCO in the medical center with experience and conditions.

Long-term outcomes of stent-related perforation in malignant colon obstruction: a systematic review and meta-analysis

PURPOSE

The placement of self-expandable metallic stents as a bridge to surgery in malignant colon obstruction is concerning due to the long-term oncological results reported in recent published studies. The aim of this study was to evaluate the oncological consequences of stent-related perforations in patients with malignant colon obstruction and potentially curable disease.

METHODS

MEDLINE, Cochrane Library, Ovid and ISRCTN Registry were searched, with no restrictions. We performed five meta-analyses to estimate the pooled effect sizes by using a random-effect model. The outcomes were global, locoregional and systemic recurrence rate and 3 and 5 year-survival rate depending on the presence or absence of stent-related perforation.

RESULTS

Thirteen studies (950 patients) were included. The overall rate of stent-related perforation was 8.9%. The global recurrence rate was significantly higher in stent-related perforation group (41.2 vs. 30.8%; OR 1.70; 95%CI: 1.02-2.84; p = 0.04). Locoregional recurrence rate was higher in the perforated group than in the non-perforated group (26.6 vs. 12.5%), with statistically significant differences (OR 2.41; 95% CI:1.33-4.34; p = 0.004). No significant differences were found in systemic recurrence rate (13.6 vs. 20.5%; OR 0.77; 95%CI: 0.35-1.7; p = 0.51); 3-year overall survival rate (65.4 vs. 74.8%; OR 0.63; 95% CI:0.29-1.39; p = 0.25) and 5-year overall survival rate (48.3 vs. 58.6%; OR 0.67; 95%CI: 0.27-1.65; p = 0.38).

CONCLUSION

Stent-related perforation is associated with an increased risk of global and locoregional recurrence. The successful placement of the stent as a bridge to surgery in the curative purpose of patients with obstructed colon cancer does not exclude the presence of underlying perforation, with the consequent danger of disease spread. PROSPERO registration number: CRD42020152817.

Long-term survival analysis after endoscopic stenting as a bridge to surgery for malignant colorectal obstruction: comparison with emergency diverting colostomy

OBJECTIVE

The use of colorectal self-expanding metal stents (SEMS) as bridge therapy for malignant colorectal obstruction was first reported more than 20 years ago. However, its use remains controversial. In this study, we aimed to compare the long-term survival of patients with potentially resectable malignant colorectal obstruction who had undergone colorectal SEMS placement and emergency surgery.

METHODS

This study was a retrospective analyses. Patients who received treatment between 2009 and 2017 were included. According to the eligibility criteria, 21 patients were included in the SEMS group and 67 patients were included in the surgical group..

RESULTS

The majority of the patients in the SEMS group were female (57.1%), whereas the majority of those in the surgical group were male (53.7%). The median follow-up time was 60 months for both groups with the same interquartile range of 60 months. There was no difference in the overall survival rate (log rank p=0.873) and disease-free survival rate (log rank p=0.2821) in the five-year analysis. There was no difference in local recurrence rates (38.1% vs. 22.4%, p=0.14) or distant recurrence rates (33.3% vs. 50.7%, p=0.16) in the SEMS and the surgical groups. Technical and clinical success rates of endoscopic stenting were 95.3% and 85.7%, respectively. There were no immediate adverse events (AEs). Severe AEs included perforation (14.3%), silent perforation (4.7%), reobstruction (14.3%), and bleeding (14.3%). Mild AEs included pain (42.8%), tenesmus (9.5%), and incontinence (4.76%). The limitations of this study was retrospective and was conducted at a single center.

CONCLUSIONS

No differences in disease-free and overall survival rates were observed in the five-year analysis of patients with resectable colorectal cancer who had undergone SEMS placement or colostomy for the treatment of malignant colorectal obstruction. Patients in the SEMS group had a higher rate of primary anastomosis and a lower rate of temporary colostomy than did those in the surgery group.

Predictors of Complications and Mortality in Patients with Self-Expanding Metallic Stents for the Palliation of Malignant Colonic Obstruction

INTRODUCTION

Self-expanding metallic stents (SEMS) for palliative purposes in malignant colonic obstruction are an alternative to surgery that has gained popularity over time.

METHODS

We performed a retrospective study of patients submitted to SEMS for palliation of obstructing malignant colorectal cancer from 2005 to 2015 to evaluate predictive clinical factors for complications and mortality.

RESULTS

Forty-five patients with high rates of technical and clinical success were included (97.8 and 95.6%, respectively), with complications occurring in 17.8% (8.9% perforations, 4.4% obstructions, and 4.4% migrations). The length of the stenosis was superior in patients with complications (p = 0.01); 11.1% of patients had a re-intervention (2.2% surgery and 8.9% placement of another SEMS). Relief of obstruction without intervention was maintained until death in 77.8% of patients and in 81.4% of patients who had immediate clinical success. The mortality rate was 37.2% at 30 days, 56.5% at 60 days, and 87.5% at 1 year. There were no predictors of survival identified, including age, sex, tumor stage, metastasis, or complications of the procedure.

DISCUSSION AND CONCLUSIONS

In this study, SEMS placement was associated with a high rate of technical and clinical success and a low rate of complications, being an option to palliate patients with obstructive neoplasia. The length of the stenosis was associated with a greater risk of complications. The majority of stent-related complications can be managed successfully without surgery.