The Use of Four-Dimensional Impedance Manometry in Predicting Therapeutic Outcomes of Peroral Endoscopic Myotomy for Achalasia.

BACKGROUND

Clinical non-response to peroral endoscopic myotomy (POEM) is a major clinical challenge of achalasia. Four-dimensional high-resolution impedance manometry (4D-HRIM) enables evaluation of both esophageal motility and bolus clearance. This study investigated whether 4D-HRIM could predict outcomes of POEM in achalasia patients.

METHODS

Achalasia patients who underwent preoperative 4D-HRIM evaluation and POEM were retrospectively included. The baseline characteristics, myotomy metrics, traditional preoperative examinations metrics, and 4D-HRIM metrics were compared between clinical response and non-response patients. Statistically significant parameters were selected to deliver receiver operating characteristic curve (ROC) analysis, with stepwise regression constructing optimal prediction models.

KEY

RESULTS

A total of 121 achalasia patients were included, of which 10 patients were assigned to the clinical non-response group. While no significant difference was found in HRM, endoscopy, and barium esophagram metrics, patients in the clinical non-response group presented higher phase-specific intrabolus pressure (IBP), increased pressure, and lower distensibility index (DI) of the esophageal body, higher pressure at EGJ, and lower retention ratio under 4D-HRIM evaluation. The area under the curve (AUC) for predicting poor outcomes using a single 4D-HRIM metric, such as phase-specific IBP or DI, ranged from 0.69 to 0.76. The combination of the median IBP at phase 2 and the retention ratio showed the best predictive performance, with an AUC of 0.817.

CONCLUSIONS AND INFERENCES: 4D-HRIM evaluation could help predict clinical outcomes after POEM in achalasia, thereby enabling us to develop personalized surgical strategies and establish more meticulous postoperative follow-up plans.