Comparison of three kinds of self-expandable metallic stents induced granulation tissue hyperplasia in the rabbit trachea

To compare stent-induced granulation tissue hyperplasia of bare (SEMS), polyurethane-covered (PU-SEMS) and electrospun nanofibre-covered (EN-SEMS) self-expandable metallic stents in the rabbit trachea. Twenty-seven rabbits were randomly assigned to 3 groups that received SEMS, PU-SEMS or EN-SEMS. Computed tomography and sacrifice were performed as scheduled. Haematoxylin–eosin and Masson’s trichrome staining protocols were performed for pathological analysis. The data for tracheal ventilation area ratio, qualitative histological scoring, number of epithelial layers, and thicknesses of papillary projection and submucosa were documented and statistically analysed. All stents were successfully placed under the guidance of fluoroscopy without complications. Post-stenting 3 and 7 days, computed tomography revealed that the fully expandable EN-SEMS was similar to the SEMS and PU-SEMS. The mean stented tissue score in the SEMS group was higher than those of both the PU-SEMS and EN-SEMS groups at 3 days post-stenting. The pathological findings suggested that there was no papillary projection formation 3 days after stent placement. The thickness of papillary projection in the SEMS group was significantly higher than those of the PU-SEMS and EN-SEMS groups at 7 days post-stenting. After stenting 4 weeks, the tracheal ventilation area ratio of SEMS, PU-SEMS and EN-SEMS was 0.214 ± 0.021, 0.453 ± 0.028 and 0.619 ± 0.033, respectively. There were significant between-group differences. In conclusion, the stent-induced granulation tissue formation in EN-SEMS is less severe than that of PU-SEMS and SEMS. EN-SEMS has smaller radial force, and the tracheal ventilation ratio after stent placement better than that of PU-SEMS.

Use of self-expandable metallic stents for endoscopic biliary decompression decreases stent complications in pancreatic cancer patients receiving chemotherapy

Background Both plastic stents and self-expandable metallic stents (SEMSes) are used for endoscopic biliary decompression (BD) among patients with pancreatic cancer (PAC). Cholangitis or stent occlusion often interrupts or ends chemotherapy. We investigated cholangitis, stent occlusion, and chemotherapy interruption rates for SEMSes and plastic stents among patients receiving chemotherapy for PAC. Materials and methods We retrospectively analyzed data for 293 PAC patients who received a biliary stent at Helsinki University Hospital during 2000–2017. Patients received chemotherapy as palliative treatment (PT: n = 187) or neoadjuvant treatment (NAT: n = 106). Among participants, 229 had a plastic stent (PT: n = 138, NAT: n = 91) and 64 had a SEMS (PT: n = 49, NAT: n = 15). Results Overall, 15.6% (n = 10) of patients with SEMSes (PT: 20.4%, n = 10, NAT: 0%) and 53.0% (n = 121) of patients with plastic stents (PT: 69.3%, n = 95, NAT: 28.5%, n = 26) experienced one or more stent complications (p < 0.001). Cholangitis developed in 6.3% (n = 8) of PT patients with SEMSes. No patients with SEMSes receiving NAT (n = 15) experienced cholangitis. However, 31.9% (PT: 42.8%, n = 59, p = 0.001; NAT: 15.4%, n = 14, p = 0.211) of patients with plastic stents developed cholangitis. Among all patients receiving NAT or PT, cholangitis interrupted chemotherapy 6 times (9.4%) in SEMS patients and 61 times (26.6%) in plastic stent patients (p = 0.004). Stent occlusion without cholangitis interrupted NAT or PT 2 times (2.1%) in SEMS patients and 31 times (13.5%) in plastic stent patients (p = 0.023). Conclusions SEMS is recommended for BD among patients with PAC receiving chemotherapy. Among both PT and NAT patients, patients with SEMS experience a lower stent failure rate, lower rate of cholangitis, and fewer chemotherapy interruptions than patients with plastic stents.

Salvage therapy of bleeding esophageal tumor by fully covered self-expandable metallic stent: A case report

The role of self-expandable metallic stents is gradually evolving for a diverse group of benign and malignant gastrointestinal tract problems, with luminal obstruction being by far the most common. Although its role in refractory variceal bleeding is well established, it has rarely been tried for tumor-related bleeding, with only a few case reports in this regard. We share our experience of successfully controlling esophageal tumor–related bleeding with the use of a fully covered self-expandable metallic stent. A 58-year-old woman with irresectable distal esophageal cancer, presented with hematemesis. Esophago-gastro-duodenoscopy revealed an obstructing esophageal tumor with diffuse oozing of blood. This was unamenable to local injection of adrenaline and hemospray; therefore, a temporary self-expandable metallic stent was parked to create a tamponade effect. This successfully stopped bleeding and the patient remained asymptomatic till discharge. However, she was lost to follow-up, and therefore, the stent was removed after a period of 5 months instead of 2 weeks.