Peroral Endoscopic Myotomy with the Stag Beetle Knife (SB Knife): Feasibility and Follow-Up.

BACKGROUND Recently, a stag beetle (SB) knife was introduced to reduce the difficulty of peroral endoscopic myotomy (POEM). The objective of this study was to evaluate the efficacy and safety of the SB knife. MATERIAL AND METHODS A total of 71 patients undergoing POEM with the SB knife for esophageal achalasia were included. We used esophagography, manometry, esophagogastroduodenoscopy (EGD), and Eckardt score to assess the utility and safety. RESULTS All cases were completed for POEM. The incidence of adverse events during the operation were 2.8%; however, all cases were treated conservatively. There was a vast improvement in clinical symptoms and endoscopic findings. The average Eckardt score was 6.9 before and 0.6 at 1 year after POEM (p<0.05). The average lower esophageal sphincter (LES) pressure before and 6 months after POEM were 44.34±14.83 mmHg and 19.14±6.74 mmHg (p<0.05), respectively. The average LES relaxation pressure before and 6 months after POEM was 12.11±5.02 mmHg and 3.22±2.29 mmHg (p<0.05), respectively. CONCLUSIONS POEM with the SB Knife is technically efficient and safe in treating achalasia and is associated with favorable short-term outcomes.

Improvement of Low-Temperature Performance of Buton Rock Asphalt Composite Modified Asphalt by Adding Styrene-Butadiene Rubber.

To improve the low-temperature performance of the Buton rock asphalt (BRA)-modified asphalt, styrene-butadiene rubber (SBR) was added to it. The BRA-modified asphalt and SBR-BRA composite modified asphalt were prepared by high-speed shearing method. The penetration, softening point, ductility, and Brookfield viscosity of the two kinds of asphalt were measured. The dynamic shear rheometer (DSR) and the beam bending rheometer (BBR) were employed to research the performance of BRA-modified asphalt by adding SBR. The results showed that the pure asphalt in BRA was the main reason to reduce the low-temperature performance of neat asphalt when the content of BRA was 19%. However, the ash in BRA was the main factor to reduce the low-temperature performance when its content was more than 39.8%. When the BRA content was 59.8%, the SBR-BRA composite modified asphalt with SBR contents of 2%, 4%, 6%, and 8%, and it shows that the penetration and ductility of the BRA-modified asphalt are increased by the addition of SBR. The equivalent brittle point was reduced, the stiffness modulus was decreased, and the creep rate was increased. At the same time, the Brookfield viscosity was reduced and the rutting factor was increased. The stiffness modulus of the SBR-BRA composite modified asphalt mixture was increased. That is to say, when SBR was mixed into the BRA-modified asphalt, the low-temperature performance could be remarkably improved based on ensuring high-temperature performance. The low-temperature index of composite modified asphalt was analyzed. It was recommended to apply the equivalent brittle point to evaluate the low-temperature performance of SBR-BRA composite modified asphalt.