EsoFLIP — Impedance-Guided Dilation

EsoFLIP uses a non-compliant balloon designed to deliver controlled radial force at preset diameters (16, 20, 25, 30 mm) while displaying real-time CSA, diameter, and intraballoon pressure. Unlike traditional pneumatic dilation — where the operator is blind during inflation — EsoFLIP shows tissue yielding live. The endpoint is no longer time or pressure but a target post-dilation EGJ-DI (usually > 3.0 mm²/mmHg) and absence of full-thickness rupture features. Reported perforation rates in early EsoFLIP series are < 1%, compared with 2–4% for conventional Rigiflex pneumatic dilation.

The EF-322B (8 cm balloon) is used at the EGJ; the EF-330B (16 cm) is being introduced for longer tubular dilations including post-anastomotic strictures. Both run on the same EF-100 console as the diagnostic catheter, so a centre with EndoFLIP already has 80% of the EsoFLIP infrastructure in place.

For type I and type II achalasia, EsoFLIP is increasingly used as a primary therapy in patients who decline POEM or surgery, or who are poor surgical candidates. The protocol: stepwise dilation 16 → 20 → 25 → 30 mm, with FLIP measurement after each step. The endpoint is EGJ-DI > 3.0 mm²/mmHg. In the Kim 2022 meta-analysis (14 studies, 632 patients), durable clinical remission at 2 years was 65–70%, comparable to conventional Rigiflex pneumatic dilation. Type III achalasia and spastic disorders respond less well to EsoFLIP — these patients benefit more from POEM.

A key advantage: the FLIP feedback lets you stop at the right point. The historical "blind" pneumatic dilation either under-treated (clinical failure) or over-treated (perforation). EsoFLIP reduces both error modes.

A tight fundoplication or under-cut POEM with persistent dysphagia is an ideal EsoFLIP indication. The pre-dilation FLIP measurement confirms an obstructive DI (< 2.0) and rules out alternative diagnoses. A single 20 or 25 mm dilation is usually sufficient — these patients typically have a localised tight zone rather than the full sphincter mass of naive achalasia, so smaller-diameter dilation suffices.

Still, escalate stepwise. The tissue planes are often inflamed or scarred and can give way unpredictably. The Familiari 2018 series of 51 post-POEM dilations reported a 0% perforation rate using stepwise EsoFLIP — versus reports of up to 5% perforation with conventional balloon dilation in the same setting.

Outside the EGJ, EsoFLIP is being studied in refractory peptic strictures, anastomotic strictures, and eosinophilic oesophagitis (EoE) fibrostenotic disease. The protocol differs: targets are stricture-specific (e.g. CSA > 90 mm² at the narrowest point) rather than DI-driven, and dilation is limited to a single ≥ 2 mm increment per session to avoid mucosal disruption — particularly in EoE, where deep tears are a recognised risk. Use of the longer EF-330B balloon allows the operator to evaluate the entire stricture length in a single fill, identifying multifocal fibrosis that traditional bougie dilation would miss.

Evidence in EoE: a small prospective series (Hirano 2022, AJG) showed FLIP-guided dilation reduced reinterventions versus standard bougie at 12 months.

EsoFLIP is contraindicated in: known active peptic ulcer or oesophagitis with deep ulcer, recent oesophageal surgery (< 4 weeks), suspected oesophageal malignancy not yet staged, severe cardiopulmonary instability, and uncorrected coagulopathy. Relative contraindications include large hiatus hernia (≥ 5 cm — the balloon may slip), recent radiotherapy to the chest, and chronic steroid use.

Adverse events to anticipate: chest pain and short-lived dysphagia are nearly universal post-dilation and are not adverse events. Mucosal tears occur in 3–5% of cases and almost always heal with conservative management (NPO 24 h, IV PPI, contrast study if clinically concerning). Full-thickness perforation (< 1% in published series) requires immediate endoscopic stent or surgical consultation. Significant bleeding is rare but possible — have an injection needle and clips on the trolley.