Novel triangle tip-jet knife increases efficiency in peroral endoscopic myotomy for achalasia

Peroral endoscopic myotomy (POEM) is performed globally for the treatment of achalasia. A newly available endoscopic knife, the triangle tip-jet (TTJ) (Olympus Triangle TipKnife-J, KD-645L), has the capability of knife dissection along with submucosal injection. We aim to present our experience with the TTJ knife in comparison to the conventional TT knife in POEM, with a focus on procedural characteristics including time, efficiency, and the number of instrument exchanges.

All patients with achalasia who underwent POEM between March 2016 and March 2020 at a single tertiary academic center were included in the retrospective cohort. Demographic, procedural, and outcomes data were compared.

Ninety-two procedures, 48 using the TT knife, and 44 with the TTJ knife were analyzed. Demographic data were similar. Procedure time was reduced using the TTJ knife (87 vs 61 min, P = <0.001) despite similar myotomy lengths (16.5 vs 15.2 cm, P = 0.09). Efficiency was increased in the TTJ group (5.5 vs 4.3 min/cm of procedure, P = 0.005). The number of instrument exchanges (16.7-1.7, P = <0.001) and usage of coagulation forceps decreased (1.7-0.5, P = <0.001). There was no difference in the procedural difficulty (POEM difficulty score [PDS] 2.2 vs 2.4, P = 0.4). Patients with higher procedural difficulty saw a greater improvement in procedural outcomes. Procedural success was high in both groups (96% vs 100%, P = 0.2). No serious adverse events were reported.

The use of the TTJ knife increases efficiency during POEM for Achalasia. The total procedure time is decreased by 28-41%, and procedural efficiency is increased by 22-34%.