Transanal Haemorrhoid Dearterialisation (THD) at Parkside Hospital

What is THD?

Transanal haemorrhoidal dearterialisation (THD) is a minimally invasive operation for haemorrhoids that doesn't remove any tissue. Instead, a surgeon uses a Doppler ultrasound probe to find and tie off the small arteries feeding blood to the haemorrhoids, which shrinks them and eases your symptoms.

What conditions does it treat?

THD is used to treat:

• internal haemorrhoids that haven't improved with conservative or topical treatments
• haemorrhoids of any grade, though it's particularly well suited to grades 2 to 4
• prolapsed haemorrhoids, where the swollen tissue bulges out of the anus, using an additional repair step alongside the artery treatment.

What are the benefits of having THD?

Because THD doesn't remove any tissue, it preserves the normal structure and function of the anal canal, and the stitches are placed in an area with few nerve endings, which is why it tends to cause less pain than more traditional haemorrhoid operations. It's usually done as day surgery, taking around 30 minutes, and most people go home on the same day, around 8 hours after their operation.

In the UK, NICE recognised THD in 2010 as an effective alternative to surgical removal of haemorrhoids or stapled haemorrhoidopexy. Recovery tends to be quick, with most people back to their normal activities within 2–3 days, and because no tissue is removed, the procedure can be repeated in future if needed.

Are there different types of surgical approaches?

THD can be performed in two ways. On its own, it involves tying off the arteries supplying the haemorrhoids, known as dearterialisation. Where there's also prolapse, this is combined with mucopexy, a stitching technique that lifts and repositions the bulging tissue back into place. Your surgeon will decide which is appropriate based on your symptoms and the grade of your haemorrhoids.

The procedure uses a specially designed proctoscope with a built-in Doppler ultrasound probe and light source, which lets the surgeon precisely locate the arteries feeding the haemorrhoids before tying them off.

What happens before the operation?

Before your operation:

• you'll have a colorectal examination and assessment, since only a specialist can confirm whether THD is the right treatment for you
• because the procedure is carried out inside the anal canal, your surgeon will usually prescribe one or two enemas beforehand to empty your bowel
• you'll be assessed for either a general or spinal anaesthetic, and your team will give you specific instructions to follow before your admission.

What happens during the procedure?

1. You're given a general or spinal anaesthetic and positioned on the operating table as your surgeon prefers.
2. A specially designed proctoscope, with a built-in Doppler ultrasound probe and light source, is gently inserted into the anal canal.
3. The Doppler signal helps your surgeon precisely locate the small arteries feeding blood to the haemorrhoids.
4. Each artery is tied off with a stitch, placed in an area of the anal canal with few nerve endings to help limit pain afterwards.
5. If you have prolapse, your surgeon also performs a mucopexy, a continuous stitch that lifts the bulging tissue and holds it back in its normal position.
6. The procedure takes around 30 minutes on average.

What does recovery look like?

THD is usually done as day surgery, and most people are ready to go home around 8 hours after the operation, once you've recovered from the anaesthetic.

Some discomfort in the area is normal and should ease over the next few days; your team can prescribe pain medication if you need it. Light bleeding straight after surgery is common and usually settles within a few hours.

A temporary urge to pass stool, even when there's nothing there, is the most common complication, linked to the prolapse repair; this is usually short-lived. Most people are back to their normal activities within 2–3 days.

What are the risks and complications?

THD has a lower rate of serious complications reported than more invasive haemorrhoid surgery, but possible effects include:

• a temporary urge to pass stool even when there's nothing there, known as tenesmus, which is the most commonly reported complication
• light bleeding in the first few hours after surgery
• discomfort or pain in the treated area for a few days
• haemorrhoids returning at some point in the future, though published recurrence rates are generally described as low
• as with any operation, a small risk of complications related to the anaesthetic.