RESUMO
The radial force of esophageal stents may not completely change during extraction and therefore, the procedure of stent removal may cause tissue damage. The present study reports the manufacture of 2 novel detachable stents, which were designed to reduce tissue damage through their capacity to be taken or fall apart prior to removal and evaluated the supporting properties of these stents and the extent of local mucosal injury during their removal. The stents were manufactured by braiding, heat-setting, coating and connecting. The properties of the stents were evaluated by determining the following parameters: Expansion point, softening point, stent flexibility, radial compression ratio and radial force. A total of 18 rabbits with induced esophageal stricture were randomly assigned to 3 groups as follows: Detachable stent (DS) group, biodegradable stent (BS) group and control group. The stricture rate, complications, survival, degradation and stent removal were observed over 8 weeks. The stents of the DS and BS groups provided a similar supporting effect. The stricture rate, incidence of complications and survival were also similar between the 2 groups, while significant differences were noted between the DS and control groups and between the BS and control groups. In the BS group, the stents were degraded and moved to the stomach within 7 weeks (2 in 6 weeks and 3 in 7 weeks). The debris was extracted using biopsy forceps. In the DS group, all stents were easy to remove and 2 cases exhibited minor hemorrhage. In conclusion, the 2 types of novel detachable stent provided an equally efficient supporting effect in vitro and in vivo and may reduce the incidence of secondary injury during stent removal.
RESUMO
OBJECTIVE: Pancreatic duct guidewire placement (PDGP) includes double guidewire technique (DGT) and transpancreatic sphincterotomy (TPS). DGT can be switched to TPS with ease due to the existing guidewire in the pancreatic duct. In this study, we aimed to combine DGT and TPS as a single technique, named sequential PDGP, and to compare its performance with needle knife precut sphincterotomy (NKPS) in treating difficult biliary cannulation (BC). METHODS: A total of 83 patients with difficult BC were enrolled in this study. Of these, 63 underwent sequential PDGP and 20 underwent NKPS. Cannulation success rate, cannulation time and endoscopic retrograde cholangiopancreatography (ERCP)-related complications were prospectively recorded and compared between the two groups. RESULTS: Successful BC was achieved in 88.9% (56/63) of the patients in the sequential PDGP group compared with 70.0% (14/20) in the NKPS group (P = 0.095). Cannulation time was 7.49 ± 5.03 min in the sequential PDGP group and 10.60 ± 7.24 min in the NKPS group (P = 0.086). Post-ERCP pancreatitis occurred in 12.7% of patients in the sequential PDGP group and 10.0% in the NKPS group (P = 1.000). There was no significant difference in the rates of other complications (bleeding, perforation and cholangitis) between the two groups. CONCLUSIONS: Sequential PDGP is a safe and effective alternative method to NKPS in cases of difficult BC. In those with failed standard cannulation, sequential PDGP can be considered when the guidewire is inadvertently inserted into the pancreatic duct or can be placed in the pancreatic duct without difficulty.
