Transanal hemorrhoidal dearterialization (THD) is a minimally invasive
surgical
Surgery ''cheirourgikē'' (composed of χείρ, "hand", and ἔργον, "work"), via la, chirurgiae, meaning "hand work". is a medical specialty that uses operative manual and instrumental techniques on a person to investigate or treat a pat ...
procedure for the treatment of internal hemorrhoids.
Background
In 1995, Morinaga et al. developed a non-excisional surgical technique for the treatment of internal
hemorrhoid
Hemorrhoids (or haemorrhoids), also known as piles, are vascular structures in the anal canal. In their normal state, they are cushions that help with stool control. They become a disease when swollen or inflamed; the unqualified term ''he ...
s. Dal Monte et al. further refined this technique, introducing transanal hemorrhoidal dearterialization (THD). THD belongs to the category of minimally invasive surgery, since the procedure does not comprise incisions or removal of the hemorrhoidal tissue.
Hemorrhoids
Hemorrhoids are normal vascular cushions found in the anal canal. 15% of a human's continence mechanism is attributed to the hemorrhoidal plexus. When a person coughs, for instance, the hemorrhoids will engorge with blood and increase one's ability to hold gas and stool. They are termed internal and external based on their positioning to an embryological line termed the
pectinate line. Hemorrhoids above the pectinate line are considered "internal" and those below it "external".
Hemorrhoids are fed by arteries and drained by veins. The arterial blood supply is based on the superior rectal (hemorrhoidal) artery. Just as veins in the leg weaken and become prominent, hemorrhoidal veins also may become varicose, resulting in internal hemorrhoids or “piles”. Internal hemorrhoids are divided into four grades. Grade I hemorrhoids are composed of prominent vessels, without protrusion. Grade II hemorrhoids demonstrate prolapse upon straining, with spontaneous reduction. Grade III hemorrhoids demonstrate prolapse upon straining and require manual reduction. Grade IV hemorrhoids prolapse and cannot be manually reduced.
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The procedure
THD uses a specially developed anoscope
An anoscopy is an examination using a small, rigid, tubular instrument called an anoscope (also called an anal speculum). This is inserted a few inches into the anus in order to evaluate problems of the anal canal. Anoscopy is used to diagnose ...
combined with a Doppler transducer to identify the hemorrhoidal arteries (originating from the superior rectal artery
The superior rectal artery (superior hemorrhoidal artery) is an artery that descends into the pelvis to supply blood to the rectum.
Structure
The superior rectal artery is the continuation of the inferior mesenteric artery. It descends into the p ...
) 2–3 cm above the pectinate line. Once the superior rectal arteries are identified through the Doppler, a suture ligation is performed to effectively decrease the blood flow to the hemorrhoidal plexus.
In case of redundant prolapse, the prolapsed mucosal membrane is lifted and sutured (with the last suture minimum 5 mm above the pectinate line), repositioning hemorrhoidal cushions in situ.
This is different from a traditional hemorrhoidectomy, which focused on excising the hemorrhoidal bundle. In this procedure, there is no tissue excision. Because the suture line is above the pectinate line, post-operative pain is minimized for patients. THD can be performed with conscious sedation
Procedural sedation and analgesia (PSA) is a technique in which a sedating/dissociative medication is given, usually along with an analgesic medication, in order to perform non-surgical procedures on a patient. The overall goal is to induce a decr ...
, local
Local may refer to:
Geography and transportation
* Local (train), a train serving local traffic demand
* Local, Missouri, a community in the United States
* Local government, a form of public administration, usually the lowest tier of administrat ...
or general anesthesia
General anaesthesia (UK) or general anesthesia (US) is a medically induced loss of consciousness that renders the patient unarousable even with painful stimuli. This effect is achieved by administering either intravenous or inhalational general ...
.
Post-operative course
After the operation, a high-fiber diet with plenty of liquids (approximately two litres per day) is recommended.
For most patients, the procedure can be performed in a day-surgery setting and normal activities can be resumed on average between two and three days post-operatively.
The affected areas usually restore their normal anatomy after two to three months.
Post-operative complications
Reports on this procedure showed low complication rates and lower postoperative pain. Postoperative bleeding and constipation were included among some of the arising complications.
References
External links
NICE
{{Operations and other procedures on the digestive system
* https://www.thdlab.us
Digestive system surgery