Identifying spastic variant of type II achalasia after treatment with high-resolution manometry and FLIP Panometry

Background: Panesophageal pressurization (PEP) defines type II achalasia on high-resolution-manometry (HRM) but some patients exhibit spasm after treatment. The Chicago Classification (CC) v4.0 proposed high PEP values as predictor of embedded spasm, yet supportive evidence is lacking. Methods: Fifty seven type II achalasia patients (47 ± 18 years, 54% males) with HRM and LIP Panometry before and after treatment were retrospectively identified. Baseline HRM and FLIP studies were analyzed to identify factors associated with post-treatment spasm, defined on HRM per CC v4.0. Results: Seven patients (12%) had spasm following treatment (peroral endoscopic myotomy 47%; pneumatic dilation [PD] 37%; laparoscopic Heller myotomy 16%). At baseline, greater median maximum PEP pressure (MaxPEP) values on HRM (77 vs 55 mmHg, p = 0.045) and spastic-reactive contractile response pattern on FLIP (43% vs 8%, p = 0.033) were more common in patients with post-treatment spasm while absent contractile response on FLIP was more common in patients without spasm (14% vs 66%, p = 0.014). The strongest predictor of post-treatment spasm was the percentage of swallows with MaxPEP ≥70 mmHg (best cut-off: ≥30%), with AUROC of 0.78. A combination of MaxPEP <70 mmHg and FLIP 60 mL pressure < 40 mmHg identified patients with lower rates of post-treatment spasm (3% overall, 0% post-PD) compared to those with values above these thresholds (33% overall, 83% post-PD). Conclusions: High maximum PEP values, high FLIP 60 mL pressures and contractile response pattern on FLIP Panometry prior to treatment identified type II achalasia patients more likely to exhibit post-treatment spasm. Evaluating these features may guide personalized patient management.