, Volume 28, Issue 4, pp 1158-1165
Date: 14 Nov 2013

Peroral endoscopic myotomy for idiopathic achalasia: randomized comparison of water-jet assisted versus conventional dissection technique

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Peroral endoscopic myotomy (POEM) has recently been introduced as a promising alternative to laparoscopic Heller myotomy for idiopathic achalasia. Several proposed technical modifications are yet to be tested in randomized trials.


The objective of our study was to evaluate efficacy and safety of water-jet (WJ) assisted POEM versus the conventional (C) technique. The clinical trial registration number is NCT01742494.


A prospective randomized trial was carried out in Zhongshan Hospital, Fudan University (Shanghai, China), in 100 consenting achalasia patients between August 2011 and April 2012. Patients eligible for POEM were randomized to use of either the HybridKnife (WJ group) or the conventional technique using injection and triangle tip knife interchangeably (C group).


A total of 100 patients with comparable characteristics between groups were included. Procedure time was significantly shorter for the WJ group (22.9 ± 6.7 vs. 35.9 ± 11.7 min; p < 0.0001), mostly due to less replacement of accessories (2.0 ± 2.4 vs. 19.2 ± 7.6; p < 0.0001). Injection volume was larger in the WJ group (45.3 ± 10.2 vs. 35.2 ± 9.5 ml; p < 0.0001) and was associated with fewer minor bleeding episodes (3.6 ± 1.8 vs. 6.8 ± 5.2; p < 0.0001). No severe complications occurred; one case of cutaneous emphysema occurred in the WJ group, and four cases occurred in the C group (p = 0.17), three cases of pneumonia were encountered in the C group and none in the WJ group (p = 0.24). Treatment success (Eckardt score ≤3) was achieved in 96.5 % of patients, with no significant differences between groups.


The use of the HybridKnife leads to a significant decrease in POEM procedure time and facilitates reinjection, possibly contributing to a lower rate of minor intra-procedural bleeding.