PROSPECTIVE ANALYSIS OF ENDOSCOPIC IMPEDANCE PLANIMETRY PYLORIC MEASUREMENTS AND ITS ASSOCIATION WITH TREATMENT OUTCOMES IN PATIENTS WITH GASTROPARESIS UNDERGOING GASTRIC PER-ORAL ENDOSCOPIC MYOTOMY (G-POEM)

Background: Endoscopic impedance planimetry (FLIP) has been used to evaluate the pyloric physiologic parameters after G-POEM for refractory gastroparesis; yet data on this technology is still limited. This study aimed to evaluate FLIP measurements and its association with clinical outcomes of patients undergoing G-POEM.
Methods: Single-center prospective study on consecutive patients with confirmed medically refractory gastroparesis who underwent G-POEM. Pylorus diameter, cross-sectional area (CSA), balloon pressure, and distensibility index (DI) were evaluated at 40 mL balloon fills in same session pre-G-POEM, post-G-POEM and subsequently at 3-month FLIP follow-up. Clinical response was defined as improvement of ≥1 point on the Gastroparesis Cardinal Symptom Index (GCSI) at follow-up.
Results: Seventy-seven patients with a median follow-up of 6 months (range 3-12) underwent G-POEM between November 2021 and June 2023. Technical success was 100%. There was one case of perforation (1.3%) managed endoscopically. Clinical success was achieved in 68% (52/77) of the patients. There were no differences in demographics, symptom duration, etiology of gastroparesis, baseline GCSI or gastric emptying scintigraphy results between responders (n=52) and non-responders (n=25) (Table 1). Patients who responded to G-POEM had a lower baseline distensibility index (DI) compared to non-responders (8.1 ± 2.6 vs. 9.9 ± 4.8 mm²/mmHg; p=0.04) (Table 1). Clinical response after G-POEM was associated with improvement in pyloric cross-sectional area (CSA) and DI (Figure 1). Post-G-POEM DI was significantly higher in the responder group (DI: 11.5 ± 3.6 vs. 9.4 ± 5.1 mm²/mmHg; p=0.04).
Conclusions: In this large prospective study with standardized FLIP measurements before and after G-POEM, we demonstrated an association between clinical response following G-POEM and improvement in CSA and pyloric distensibility. Notably, baseline pyloric distensibility, which was significantly lower among clinical responders, may be a potential predictor of treatment response to G-POEM. Future multi-center studies on G-POEM with standardized FLIP protocols are needed to corroborate these initial findings and determine whether this tool can be used to more accurately predict clinical response.