Outcomes Following Esophageal Hydraulic Dilation in Patients With Disorders of Esophagogastric Junction Outflow

The primary goal in managing achalasia and disorders of esophagogastric junction (EGJ) outflow obstruction (EGJOO) is to disrupt the lower esophageal sphincter and improve bolus emptying.^1,2 Definitive treatments include laparoscopic Heller myotomy and peroral endoscopic myotomy (POEM), though some patients are not candidates or prefer less-invasive options.³ A less-invasive option includes pneumatic dilation, which is performed under fluoroscopy and often requires repeat procedures.^2,4 Esophageal hydraulic balloon dilation using the EsoFLIP system is a newer alternative approach to pneumatic dilation that combines impedance planimetry with a hydraulic balloon to enable controlled dilation and real-time assessment of EGJ diameter. This enables intraprocedural feedback, allows adjustable balloon sizing, and eliminates the need for fluoroscopy.⁵ Although long-term data remain limited, early studies show promising short-term outcomes.⁶ This study evaluates short- and long-term outcomes and adverse events following hydraulic balloon dilation using the Medtronic ES-330 catheter in patients with achalasia and other EGJ outflow disorders.

This retrospective study analyzed prospectively collected data from consecutive adults (≥18 years) with achalasia or other EGJ outflow disorders who underwent esophageal hydraulic balloon dilation between June 2020 and July 2025 at a single tertiary referral center, approved by the institutional review board.

High-resolution impedance manometry was performed to classify esophageal motor disorders according to the Chicago Classification version 4.0, following the standardized protocol it recommends.⁷ As part of a standardized pretreatment evaluation, patients also received a timed barium esophagogram with tablet, upper endoscopy, and functional lumen imaging planimetry (FLIP) to confirm EGJ outflow obstruction. All available diagnostic investigations were reviewed prior to proceeding with EsoFLIP dilation to guide therapeutic decision-making.

Hydraulic balloon dilation was performed using FLIP topography with the Medtronic ES-330 catheter, allowing dilation up to a 30-mm target diameter. The balloon was initially inflated to 20 mL to confirm positioning across the EGJ, followed by stepwise dilation guided by real-time EGJ measurements. After dilation, the balloon was deflated, and the EGJ was inspected endoscopically for mucosal injury.

Data collection included demographics, clinical history, and symptom severity obtained through patient questionnaires and electronic medical records, managed in REDCap. Symptom severity was assessed using the Eckardt Score (ES).

The primary outcome was clinical success, defined as a postprocedure ES ≤3. Secondary outcomes included adverse events, changes in EGJ metrics by FLIP, proton pump inhibitor (PPI) use, and need for repeat or alternative therapies.

Categorical variables are reported as frequencies and percentages, and continuous variables as mean (standard deviation [SD]). Pre- and postprocedure ESs were compared using paired t tests. Missing data were not imputed. Statistical analyses were performed in R, with significance set at P < .05.

Thirty patients (53% female; mean age, 62.7 years [SD, 16.1 years]; body mass index, 24.7 kg/m² [SD, 5.7 kg/m²]) underwent successful esophageal hydraulic balloon dilation (Table 1). Diagnoses included achalasia type I (30%), achalasia type II (50%), and EGJOO (3%). In patients unable to undergo high-resolution impedance manometry, FLIP-based diagnoses included achalasia (7%), incompletely treated achalasia post-Heller myotomy (7%), and postfundoplication outflow obstruction (3%). Seven patients (23%) had a history of previous endoscopic or surgical treatments. At baseline, patients had a mean ES of 6.6 ± 2.8, and a mean integrated relaxation pressure of 24.1 mm Hg (SD, 8.2 mm Hg). FLIP metrics showed EGJ distensibility index of 1.7 mm²/mm Hg (SD, 1.5 mm²/mm Hg), diameter of 9.2 mm (SD, 7.1 mm), and pressure of 40.2 mm Hg (SD, 19.5 mm Hg) at 60 mL fill volume.

Table 1.

Demographic and Clinical Parameters

Parameters	Baseline (predilation), N = 30
Female sex	16 (53)
Age, y	62.7 (16.1)
Body mass index, kg/m2	24.7 (5.7)
Race
White	17(57)
Asian	4(13)
Other or mixed	9 (20)
Hispanic ethnicity	20 (67)
Pre-EsoFLIP diagnosis Chicago classification 4.0 diagnosis on HRM
Type 1 achalasia	9 (30)
Type II achalasia	15 (50)
EGJOO	1 (3.3)
Diagnosed on FLIP
Type 1 or II achalasia	2 (6.7)
Status post Heller myotomy with incompletely treated achalasia	2 (6.7)
Postfundoplication outflow obstruction	1 (3.3)
Baseline integrated relaxation pressure, mm Hg (n = 21)	24.1 (8.2)
Prior treatments	7(23)
Botox	1 (3.3)a
Heller myotomy	6 (20)b

NOTE. Data are presented as number (%) for categorical variables or mean (standard deviation) for continuous variables.

EGJOO, esophagogastric junction outflow obstruction; FLIP, functional luminal impedance planimetry; HRM, high resolution manometry.

^aBotox injection occurred 14 years prior to EsoFLIP.

^bHeller myotomy occurred on average at 22.8 ± 12.1 years before EsoFLIP.

All procedures were successfully completed with stepwise distension to final volumes between approximately 50 and 70 mL to achieve a 30-mm waist diameter at the EGJ without any periprocedural complications. Among 23 patients with follow-up at 2.8 months (SD, 4.5 months), 78.3% achieved ES ≤3. The mean ES improved significantly from 6.6 (SD, 2.8) to 2.6 (SD, 1.7) (P < .001). No baseline factors were associated with response. Six patients underwent follow-up FLIP at 6.8 months (SD, 1.3 months), demonstrating significant improvements in distensibility index (1.1 [SD, 0.6]-4.6 [SD, 2.2] mm²/mm Hg; P = .01) and diameter (7.5 [SD, 2.1]-14.8 [SD, 3.5] mm; P = .02).

At 1 year (12.1 months [SD, 9.2 months]), 64% maintained ES ≤3, with a mean ES of 2.11 (SD, 2.5). Seven of 24 patients (29%) underwent additional intervention after 9.4 months (SD, 5.6 months) (4 repeat dilations, 3 POEMs). Sixteen patients used PPIs postprocedure, including 2 new initiations (8%).

Esophageal hydraulic balloon dilation is an emerging minimally invasive therapy for achalasia and EGJOO. Prior studies suggest favorable safety and symptom outcomes but are limited by small cohorts and heterogeneous methods.⁶ In our cohort, initial clinical success (ES ≤3) was 78%, exceeding pooled estimates, although longer-term outcomes approached published rates. This likely reflects careful patient selection, a standardized technique, and consistent FLIP use.

Physiologic outcomes offer additional insight. Among patients who underwent repeat FLIP, distensibility and diameter improved, consistent with enhanced sphincter compliance.⁸ However, most required reintervention, likely reflecting selection bias, as repeat FLIP was performed in symptomatic patients. Postprocedural PPI use was low, with only 2 new prescriptions, comparable to pneumatic dilation and lower than typically reported after POEM.⁹

Hydraulic balloon dilation may offer advantages over pneumatic dilation, including avoidance of fluoroscopy and potentially lower perforation risk. However, pneumatic dilation remains supported by robust long-term data and retains an important role, particularly when larger dilation diameters are required.

Durability is an important consideration. Fewer than one-third of patients required reintervention, typically after 6 months, rates comparable to pneumatic dilation (approximately 25%−60% depending on follow-up and definitions).^2,10 These findings suggest that hydraulic dilation provides meaningful symptom relief with acceptable short-term durability in selected patients.

Strengths of this study include prospective data collection and detailed physiologic characterization. Limitations include modest sample size, single-center design, nonstandardized follow-up, and missing data from patients lost to follow-up. Inclusion of patients with prior Heller myotomy introduces heterogeneity that may influence outcomes.

This study adds real-world evidence integrating symptom outcomes, reintervention timing, PPI use, and FLIP data. Esophageal hydraulic balloon dilation using EsoFLIP appears safe and effective, supporting its role as a minimally invasive option. Larger multicenter studies with standardized follow-up and comparative trials are needed to better define its clinical role and Q¹¹ long-term durability.