It works from inside the gut wall. Between the inner lining and the outer muscle lies a thin submucosal layer, and the endoscope can open a tunnel in that space and work there. Passed through the mouth or the anus, it lets the doctor cut a tight muscle, remove a tumour or divide a pouch without a single cut on the skin. Third space endoscopy now offers an option for problems that once meant surgery.
According to Dr. Vipulroy Rathod, Gastroenterology Specialist in Mumbai, “What I value in third space work is that the lining stays intact over the tunnel and acts as its own protective cover. That is what lets us treat achalasia or a tumour under the lining without any incision on the abdomen. But it demands training and the right choice of patient, and I would rather decline than treat the wrong one.”
Would you like to learn whether third space endoscopy is suitable for different GI conditions?
How Does Third Space Endoscopy Work?
- The “third space”: This is the potential space between the inner lining (mucosa) and the muscle layer of the gut wall. Fluid is injected to lift the lining and create room to work. Our service page on third space endoscopy covers the basics.
- A tunnel under the lining: A small opening is made in the lining, and the doctor tunnels beneath it to reach the muscle or the lesion. The lining above acts like a protective flap.
- Closing up: Once the work is done, the opening is closed with clips. Nothing is cut on the outside of the body.
- Built on ESD skills: The dissection technique is close to endoscopic submucosal dissection (ESD). If you want that background, read What Is Endoscopic Submucosal Dissection?
Which Complex GI Conditions Can Third Space Endoscopy Treat?
- Achalasia (POEM): When the valve at the lower end of the food pipe won’t relax, food gets stuck. POEM cuts that muscle from inside. Trials suggest it works better than balloon stretching and about as well as surgery. See swallowing difficulty: causes and when it’s serious and balloon dilation for strictures.
- Severe gastroparesis (G-POEM): In stubborn cases, the muscle at the stomach’s exit (the pylorus) is cut so food can empty. It helps many patients, though long-term results are still being studied.
- Pouches in the food pipe (Z-POEM and D-POEM): The wall between a pouch (diverticulum) and the food pipe is divided so food stops collecting in it.
- Tumours under the lining (STER): Growths sitting beneath the surface can be removed through a tunnel, often without surgery. They’re usually assessed first with endoscopic ultrasound (EUS). See also endoscopic resection of tumors.
What Determines the Right Treatment Approach?
- Your exact diagnosis: The right procedure depends on what’s wrong. Swallowing tests, endoscopy and sometimes a CT scan confirm the condition and rule out look-alikes before anything is planned.
- The lesion’s size, depth and position: For tumours, EUS shows which layer the growth sits in. That decides whether tunnelling is safe or whether another method suits better.
- Scarring from earlier treatment: Previous procedures or radiation can leave scar tissue in the wall. This can make tunnelling difficult, and it may change the plan.
- Your options and priorities: Balloon stretching, medicines and surgery are alternatives. Acid reflux can follow POEM, so it’s discussed beforehand. See our page on endoscopic treatment for GERD.
Key Takeaways
- Third space endoscopy treatment works inside the gut wall through the mouth or anus, with no cuts on the skin.
- It treats achalasia, severe gastroparesis, diverticula and tumours beneath the lining.
- It’s an advanced technique that needs an experienced endoscopy team.
- Proper tests decide whether it suits you.
- Acid reflux can follow POEM. Ask about it before you decide.
Frequently Asked Questions
It’s an endoscopic procedure, not open or keyhole surgery. Everything is done through the scope, with no cuts on the skin. It’s still an advanced procedure and is done under anaesthesia.
It varies with the procedure. Hospital stays are generally shorter than after surgery. Your team will give you a diet and activity plan. Our guide on recovery after endoscopic procedures gives a general idea.
Bleeding, infection, a leak at the closure site and, after POEM, acid reflux. Your doctor will explain how these apply to your case.
For achalasia, studies follow patients for up to five years and results are good. For gastroparesis, long-term outcomes are less certain. Follow-up visits are important.
Disclaimer: This blog is for educational and informational purposes only and should not be considered professional advice.
