Abstract:Objective To analyze the risk factors for gas‑related complications during peroral endoscopic myotomy (POEM) in patients with achalasia (AC), and to construct a nomogram prediction model. Methods The clinical data of AC patients who underwent POEM from January 2012 to December 2022 at the First Affiliated Hospital of Army Medical University were retrospectively analyzed. The included cases were randomly divided into a modeling group (146 cases) and a validation group (37 cases). Risk factors for gas‑related complications were screened based on univariate and multifactorial analyses in the modeling group, and a nomogram prediction model was developed. Results Gas‑related complications occurred in 91 (49.73%) of 183 AC patients who received POEM. Myotomy length, Eckardt score, operative time, hypertension, myotomy approach, past history, serum creatinine, platelets, and serum urea nitrogen were the influencing factors for the development of gas‑related complications on univariate analysis (P<0.05). Multivariate analysis showed that the operative time >2 h (OR=2.03, 95%CI: 1.06-3.87, P=0.032), myotomy length >10 cm (OR=7.55, 95%CI: 3.09-18.45, P<0.001), the total myotomy (OR=4.61, 95%CI: 1.50-14.20, P=0.008), Eckardt score of 2 or 3 (OR=6.14, 95% CI: 2.73-13.80, P<0.001), hypertension (OR=22.69, 95%CI: 2.71-189.74, P=0.004), previous surgical treatment (OR=5.27, 95%CI: 1.57-17.66, P=0.007) and increased serum urea nitrogen (OR=1.21, 95%CI: 1.01-1.45, P=0.036) were the independent risk factors for gas‑related complications in POEM. Incorporating the above independent risk factors into the prediction model, the area under the receiver operating characteristic curve for this model was 0.833 and 0.912 for the modeling and validation groups, respectively. Calibration curves, clinical decision curves, and Hosmer‑Lemeshow tests were used to validate and evaluate the measurement model, showing that it had excellent predictive power. Conclusion This nomogram prediction model constructed with operative time, myotomy length, myotomy approach, hypertension, previous history, Eckardt score, and serum urea nitrogen has good discrimination and calibration in predicting gas‑related complications of POEM and has clinical reference value.