Pyloric impedance planimetry during endoscopic per-oral pyloromyotomy guides myotomy extent

Background: Per-oral pyloromyotomy (POP), also known as gastric per-oral endoscopic myotomy, is the first-line endoscopic intervention for medically refractory gastroparesis. This study aimed to assess the value of pyloric impedance planimetry using a functional lumen imaging probe (FLIP) during POP.

Methods: Patients who underwent POP between October 2019 and February 2024 were retrospectively reviewed. FLIP measurements, symptoms measured using the Gastroparesis Cardinal Symptom Index (GCSI), and gastric emptying scintigraphy (GES) were evaluated before and after POP.

Results: Of 35 patients who underwent POP, 29 (82.9%) were female, the median age was 51.3 years (IQR, 38.4-60.9), and the median body mass index was 29.26 kg/m² (IQR, 25.46-32.56). In addition, 23 patients had pre- and post-POP FLIP measurements. The median pyloric diameter increased from 14.4 (IQR, 12.0-16.0) to 16.0 (IQR, 14.8-18.0) mm (S = 116.5; P < .0001). The median distensibility index increased from 4.85 (IQR, 3.38-6.00) to 8.45 (IQR, 5.25-11.00) mm²/mm Hg (S = 112; P < .0001). The management changed based on FLIP values for 5 patients (21.7%), prompting additional myotomy. At 18.0 days (IQR, 12.8-47.8) after the procedure, the median GCSI score decreased from 3.33 (IQR, 2.56-4.12) preoperatively to 2.00 (IQR, 1.00-2.89) postoperatively (S = -193; P < .001). At a median follow-up of 136 days (IQR, 114-277), improvement in GCSI score persisted, with a median score of 2.44 (IQR, 1.44-3.67) (S = -61; P = .021). The median retention at 4 hours on GES decreased from 29.0% (IQR, 16.5-52.0%) to 19.5% (IQR, 5.75-35.30%) at 97 days (IQR, 88-130) after the procedure (S = -108; P = .0038). There was a 75% improvement and a 40% normalization in objective gastric emptying (n = 26). A greater increase in diameter after pyloromyotomy was associated with a greater decrease in 4-hour gastric retention (r = -0.4886; P = .021).

Conclusion: POP with FLIP resulted in clinical and radiographic improvements in patients with gastroparesis. FLIP measurements guided myotomy extent, changing the management in 21.7% of patients, and were associated with gastric emptying, demonstrating its distinct utility in the treatment of gastroparesis.