STER — Removing Esophageal Tumours Without Open Surgery: A Procedure Most Patients Have Never Heard Of

Imagine being told there is a tumour in the wall of your esophagus — and then being told that the way to remove it involves opening your chest. That's the situation patients with esophageal submucosal tumours have historically faced. The tumour is benign in most cases. It isn't cancer. It isn't spreading. But it sits in the muscular wall of the food pipe, and the only way to reach it used to be thoracoscopy — a chest operation — or open thoracic surgery.
STER — Submucosal Tunneling Endoscopic Resection — changed that calculation entirely.

What Are Esophageal Submucosal Tumours?

Most people associate esophageal disease with the inner surface of the food pipe — ulcers, cancers, polyps. But some lesions grow not on the surface but within the wall of the esophagus itself, beneath the inner lining. These are called submucosal tumours (SMTs) or subepithelial tumours — lesions whose surface is covered by normal-looking mucosa, making them invisible to standard endoscopy unless you're specifically looking for the characteristic bulge they create. The most common types found in the esophagus are:

Leiomyoma

The most common benign esophageal submucosal tumour. Arises from the smooth muscle of the esophageal wall. Most are asymptomatic and found incidentally. Larger ones can cause dysphagia — difficulty swallowing — and a sensation of food sticking in the chest. Leiomyomas are almost always benign and do not transform into cancer.

GIST — Gastrointestinal Stromal Tumour

GISTs can occur anywhere in the GI tract. Esophageal GISTs are less common than gastric or small intestinal GISTs but share the same origin — interstitial cells of Cajal in the muscular wall. Unlike leiomyomas, GISTs carry malignant potential — small, low-risk GISTs are generally curable with complete resection, while larger or high-risk GISTs may need additional treatment. Differentiating leiomyoma from GIST requires endoscopic ultrasound and, often, a tissue biopsy.

Other Submucosal Lesions

Granular cell tumours, schwannomas, and lipomas can also arise in the esophageal wall. The principles of STER apply to all of them, though suitability for the endoscopic approach depends on the specific lesion characteristics.

How Are These Tumours Diagnosed?

The typical pathway is: a patient has an upper GI endoscopy for some other reason — reflux, a symptom check — and the endoscopist notices a submucosal bulge. The surface looks normal. An endoscopic ultrasound (EUS) is then performed to characterise the lesion: its layer of origin within the esophageal wall, its size, its echogenicity, and whether there are any features suggesting malignant potential. EUS is critical before STER. It confirms that the tumour arises from the muscularis propria — the deep muscular layer — which is the indication for STER. It also helps estimate size, assess for any involvement of adjacent structures, and guide the decision about whether endoscopic removal is appropriate versus surveillance. A fine needle biopsy (FNB) guided by EUS can provide tissue for histological diagnosis, particularly important for distinguishing leiomyoma from GIST.

What Does STER Actually Involve?

STER uses the same submucosal tunneling principle as POEM — working in the 'third space' between the esophageal lining and the muscular wall. Here is the sequence:

1. The patient is under general anaesthesia. An endoscope is passed through the mouth into the esophagus.
2. A submucosal injection creates a fluid cushion that separates the inner lining from the muscular layer below it.
3. A small incision is made in the esophageal lining, 3–5 cm above the tumour site. The endoscope is advanced into the submucosal space, creating a tunnel that approaches the tumour from above.
4. Working within the tunnel, the tumour is carefully dissected free from the surrounding muscle fibres. The submucosal approach preserves the overlying mucosa throughout — this is the key to the procedure's safety.
5. Once fully dissected, the tumour is extracted through the endoscope. No incision in the chest or abdomen.
6. The entry point in the esophageal lining is closed with endoscopic clips. No external wound.

The procedure typically takes 45 to 90 minutes depending on tumour size and location. Most patients are hospitalised for two to four days, managed on antibiotics and a liquid diet initially, and discharged when they are tolerating soft foods. Recovery to normal activity takes one to two weeks.

What the Data Shows

STER was introduced clinically in Asia — primarily China and Japan — in the early 2010s and has since been validated in multiple studies including Indian data. Research published in the Indian Journal of Gastroenterology on STER outcomes in upper GI subepithelial tumours demonstrated technical success in 97.7% of cases and en bloc removal in 88.4%, with no major adverse events. These are outcomes that are genuinely difficult to match with thoracoscopic surgery in terms of recovery profile, while achieving equivalent or superior tumour removal rates for appropriate lesions. STER works best for tumours that are up to 3–4 cm in size, located in the esophagus or at the gastroesophageal junction, and arising from the muscularis propria layer. Very large tumours, tumours with irregular extension into surrounding structures, or those with features suggesting high-grade malignancy may require a different approach.

The Alternative — Why Open Chest Surgery Carries a Different Risk Profile

For a benign leiomyoma — which is what the majority of esophageal submucosal tumours turn out to be — the prospect of a thoracoscopy or open thoracotomy is significant. Chest surgery involves lung deflation on the operated side, chest tubes post-operatively, risk of pleural effusion, pain that limits deep breathing, and a recovery measured in weeks to months. For a tumour that poses no immediate threat to life and may have been found incidentally, many patients reasonably want to know if there is a less invasive option. For appropriately selected patients, STER provides that option — with comparable rates of complete removal, dramatically shorter recovery, and no thoracic morbidity.

What to Do if You Have a Submucosal Esophageal Tumour

If you have been told — on endoscopy or imaging — that there is a lesion in the wall of your esophagus, the next step is an endoscopic ultrasound (EUS) to characterise it properly. The EUS findings will determine: is this a candidate for STER? Does it need open surgery? Is it something that can safely be watched? At Medicover Hospitals, Secunderabad, I perform both the diagnostic EUS and, where appropriate, the STER procedure. If you have had a recent EUS report already, bring it to the consultation — the images and measurements are more informative than a written summary. Patients from Andhra Pradesh — from Vizag, Vijayawada, Guntur, or other cities — who have been told they have an esophageal tumour and are facing the prospect of thoracic surgery should be aware that an endoscopic assessment at Medicover Secunderabad can determine whether STER is an option for their case.
Book a consultation at Medicover Hospitals, Secunderabad — call +91 9154532511 or WhatsApp the same number.

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