Double-layered covered stent for the treatment of malignant oesophageal obstructions: Systematic review and meta-analysis

Abstract

AIMTo investigate the efficacy of double-layered covered stent in the treatment of malignant oesophageal obstructions.METHODSA systematic review and meta-analysis was performed following the PRISMA process. PubMed (Medline), EMBASE (Excerpta Medical Database), AMED (Allied and Complementary medicine Database), Scopus and online content, were searched for studies reporting on the NiTi-S polyurethane-covered double oesophageal stent for the treatment of malignant dysphagia. Weighted pooled outcomes were synthesized with a random effects model to account for clinical heterogeneity. All studies reporting the outcome of palliative management of dysphagia due to histologically confirmed malignant oesophageal obstruction using double-layered covered nitinol stent were included. The level of statistical significance was set at α = 0.05.RESULTSSix clinical studies comprising 250 patients in total were identified. Pooled technical success of stent insertion was 97.2% (95%CI: 94.8%-98.9%; I2 = 5.8%). Pooled complication rate was 27.6% (95%CI: 20.7%-35.2%; I2 = 41.9%). Weighted improvement of dysphagia on a scale of 0-5 scoring system was -2.00 [95%CI: -2.29%-(-1.72%); I2 = 87%]. Distal stent migration was documented in 10 out of the 250 cases examined. Pooled stent migration rate was 4.7% (95%CI: 2.5%-7.7%; I2 = 0%). Finally, tumour overgrowth was reported in 34 out of the 250 cases with pooled rate of tumour overgrowth of 11.2% (95%CI: 3.7%-22.1%; I2 = 82.2%). No funnel plot asymmetry to suggest publication bias (bias = 0.39, P = 0.78). In the sensitivity analysis all results were largely similar between the fixed and random effects models.CONCLUSIONThe double-layered nitinol stent provides immediate relief of malignant dysphagia with low rates of stent migration and tumour overgrowth

A viewpoint on material and design considerations for oesophageal stents with extended lifetime

“…The Niti-S design incorporates an inner dog-boneshaped NiTiNOL stent covered in a polyurethane layer surrounded by an uncoated NiTiNOL mesh (Fig. 11) [35,36]. The uncoated mesh allows tissue ingrowth to occur, thus improving anchorage and reducing the risk of stent migration.…”

Recent Advances in Manufacturing Innovative Stents

“…The performed experiments have shown a suitable adherence of PUR coating to the stent surface, as well as improved biocompatibility and long-term stability comparing to the non-coated stents [18,[35][36][37][38]. Since the beginning of using polyurethane as a stent coating material (early 1990s), such stents were applied in coronary artery perforation [37], for treatment of esophagorespiratory fistulas [38,39], recurrent benign urethral stricture [40], malignant biliary [41,42], esophageal [43,44] or gastroduodenal obstruction [45], and irresectable esophageal carcinoma [46].…”

Self-Expandable Metallic Stent Placement for the Palliation of Esophageal Cancer

“…Systematic review and meta-analysis studies have demonstrated a technical success rate of virtually 100% and improvements in dysphagia scores by at least 2 points within 1–2 days of the procedure in > 95% patients (327282930). Self-expandable plastic stents (SEPS) are similar to SEMS with regard to relief of dysphagia in the short term, but adverse events such as migration occur more often with SEPS (31), making SEMS preferable over SEPS for palliating malignant esophageal strictures.…”

“…In several randomized controlled trials, SEMS placement has been shown to provide superior efficacy to photodynamic therapy, laser therapy, and surgical bypass for the palliation of malignant esophageal strictures ( 21 22 23 24 25 26 ). Systematic review and meta-analysis studies have demonstrated a technical success rate of virtually 100% and improvements in dysphagia scores by at least 2 points within 1–2 days of the procedure in > 95% patients ( 3 27 28 29 30 ). Self-expandable plastic stents (SEPS) are similar to SEMS with regard to relief of dysphagia in the short term, but adverse events such as migration occur more often with SEPS ( 31 ), making SEMS preferable over SEPS for palliating malignant esophageal strictures.…”

“…Complications of SEMS placement can also be classified as major and minor. Major complications are life-threatening conditions such as ERF, bleeding, and perforation; minor complications are those that are not life-threatening, including migration, tumor ingrowth and overgrowth, and food impaction ( 3 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 ).…”