Endoscopic Dilators: Savary-Gilliard, Balloon, and How to Choose
Clinical guide for gastroenterologists and endoscopists · Colombia 2026
Endoscopic dilators: types, indications, and how to choose between Savary-Gilliard and balloon
Esophageal stenosis, achalasia, post-surgical dysphagia — the complete clinical guide to endoscopic dilators: types, techniques, the rule of three, and when to use bougies vs. pneumatic balloon
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GSMED Imaging Technical-Clinical Team
Content based on: Scielo ISCIII Spain (Factors associated with complications in esophageal dilations, 2018), Encolombia Gastroenterology (Esophageal Dilation), Elsevier Gastroenterology and Hepatology (Practical guide on indications and dilation techniques), Endomedica (Savary-Gilliard Dilator), and AEEED (Experience in esophageal dilation, 2016).
ℹ️ Content for professionals: This guide is intended for gastroenterologists, endoscopists, and nursing staff in endoscopy units. Endoscopic dilation procedures must be performed by certified medical personnel.
Endoscopic dilation is one of the most common therapeutic procedures in a digestive endoscopy unit. The choice between Savary-Gilliard bougies and a dilation balloon is not trivial — each type has specific technical characteristics, advantages, and risks that determine which equipment to choose based on the pathology, the location of the stenosis, and the operator's experience.
1. What is endoscopic dilation, and when is it indicated?
Endoscopic dilation is a therapeutic procedure consisting of the progressive introduction of devices of increasing caliber through a stenosis (narrowing) of the digestive tract or another tubular cavity, with the aim of widening its diameter and restoring normal passage. It is the treatment of choice for most benign esophageal stenoses and is also used for stenosis of the pylorus, colon, bile duct, and urethra.
The most common indications for endoscopic esophageal dilation are:
- Benign peptic stenosis: the most common — secondary to chronic gastroesophageal reflux with scarring. Usually located in the lower third of the esophagus.
- Schatzki ring: mucosal membrane at the esophagogastric junction. Generally responds very well to one or a few dilation sessions.
- Achalasia: esophageal motor disorder with lack of relaxation of the lower esophageal sphincter. Requires pneumatic dilation with a large-diameter balloon (30–40 mm).
- Post-surgical anastomotic stenosis: after esophageal, gastric, or bariatric surgery. Usually requires multiple sessions.
- Caustic stenosis: after accidental or intentional ingestion of acids or alkalis. Complex — high recurrence rate and greater risk of perforation.
- Radiation stenosis: secondary to thoracic or neck cancer treatment. Highly refractory — requires multiple sessions and sometimes stents.
2. Types of dilators: complete classification
🔵Mercury bougies (Hurst and Maloney)
Rubber or silicone dilators filled with mercury that are passed blindly, without a guide and without an endoscope. Hurst bougies have a blunt tip, while Maloney bougies have a tapered tip. They are the oldest — predating the flexible endoscope. Practically obsolete in modern practice due to the inability to guide the passage and the risk of perforation in complex stenoses. They are still used for the maintenance of well-known simple stenoses.
→ Only for simple and well-known stenoses · Progressively obsolete
🟣Savary-Gilliard dilators (polyvinyl bougies)
Semi-rigid polyvinyl bougies that are passed over a flexible wire guide (Savary guide) previously positioned with the endoscope. Available in calibers from 15 Fr to 60 Fr. The tapered tip and progression over a guide make this system safe and controlled. The operator perceives the resistance of the stenosis ("tactile sensation") during passage — a key advantage over the balloon. Reusable with proper disinfection. Reference in the Scielo ISCIII article: the Savary-Gilliard dilator was the authors' preferred choice due to a greater sensation of the stenosis and a lower complication rate.
→ Peptic stenosis · Schatzki ring · Anastomotic stenosis · The most widely used worldwide
🟡Dilation balloon (TTS — Through-The-Scope)
Catheter with an inflatable balloon that is passed through the endoscope's biopsy channel (TTS) or over a guide. The balloon is inflated with water or saline solution under pressure control until the desired diameter is reached. Balloon length: 3–8 cm. Dilation is purely radial (it does not have a shearing component like bougies). It allows real-time visualization of the dilation of the stenosis. The main disadvantage is the lack of tactile sensation for the operator. Available in diameters from 6 mm to 25 mm depending on the indication.
→ Pyloric stenosis · Short stenoses · Under direct anesthesia · Alternative to Savary in experienced hands
3. The rule of three — the fundamental safety principle
The rule of three (Rule of Three) — Langdon 1997 In each esophageal dilation session, no more than 3 consecutive dilators exceeding the initial point of resistance should be passed. In practice: if the first caliber where resistance is perceived is, for example, 33 Fr, then 36 Fr and 39 Fr (three more calibers) can be passed in that session, but not beyond that. This empirical rule seeks to balance therapeutic efficacy with safety — most perforations occur when pressure is applied beyond the tissue resistance limit. It applies mainly to Savary-type bougies, where the tactile sensation allows the identification of the point of resistance.
4. Savary-Gilliard vs. balloon — when to use each
| Feature | Savary-Gilliard (bougie) | TTS Balloon |
|---|---|---|
| Mechanism | Axial + radial dilation with shearing | Pure radial dilation without shearing |
| Operator tactile sensation | High — perceives stenosis resistance | Absent — only manometric control |
| Requires wire guide | Yes — preplaced Savary guide | Yes (over guide) or No (direct TTS) |
| Requires radiological control | Optional in simple stenoses | Optional in simple stenoses |
| Can be done during diagnostic endoscopy | No — requires a separate session | Yes — TTS balloon in the same procedure |
| Short and accessible stenoses | Good | Excellent |
| Long and complex stenoses | Excellent | Moderate |
| Learning curve | Moderate | Steep — requires experience in balloon manometry |
| Device cost | Low (reusable) | High (disposable) |
| Preferred choice according to Scielo ISCIII 2018 | Preferred for tactile sensation and fewer complications | Valid — higher perforation rate in that study |
5. Complications of endoscopic dilation
- Esophageal perforation (0.1–2.6%): the most serious. Mortality rate up to 20% if not detected and treated in time. Risk factors: complex stenoses, eosinophilic esophagitis, post-radiation stenosis, operator's lack of experience. Suspicion: post-dilation chest pain, subcutaneous emphysema, fever. Diagnosis: chest CT. Treatment: surgery or endoscopic stent depending on the case.
- Bleeding (0.5–1%): generally mild and self-limiting. Rarely requires endoscopic hemostatic intervention.
- Transient bacteremia: frequent but rarely clinically significant. Antibiotic prophylaxis only in high-risk patients according to guidelines.
- Stenosis recurrence: it is not an acute complication but is the natural reality of many stenoses — especially those caused by caustics or radiotherapy. Requires a program of periodic maintenance dilations.
6. Frequently asked questions
How many dilation sessions does a patient with esophageal stenosis need?
It depends entirely on the cause and the characteristics of the stenosis. Simple stenoses (Schatzki ring, mild peptic stenosis) can be resolved with 1 to 3 sessions. Refractory complex stenoses (caustics, post-radiation) may require multiple sessions over months or years, and sometimes the combination of dilation with intralesional corticosteroid injection (triamcinolone) to reduce recurrence. In the RAPD 2013 study with combined therapy, patients with refractory stenoses moved to a maintenance protocol with a median of 3.7 combined sessions after 11.9 months of previous conventional dilations.
Is the Savary-Gilliard dilator reusable?
Yes, Savary-Gilliard dilators are designed as reusable devices — unlike TTS balloons, which are single-use. However, reuse requires: visual inspection before each use to verify material integrity (no cracks, deformations, or damage to the tip), immediate manual cleaning post-procedure, high-level disinfection (HLD) with glutaraldehyde or equivalent according to institutional protocol, and proper storage. According to the Endomedica technical sheet, the device "is supplied non-sterile and is reusable if the integrity of the device is intact". If there is any doubt about its integrity, it must be discarded.
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