Overview
Definition:
Transanal Hemorrhoidal Dearterialization (THD) is a minimally invasive surgical technique used to treat symptomatic hemorrhoids by ligating the terminal branches of the superior rectal arteries
This procedure reduces blood flow to the hemorrhoidal cushions, causing them to shrink and detaching them from the underlying vascular pedicles.
Epidemiology:
Hemorrhoids affect a significant portion of the adult population, with estimates ranging from 4% to 86% experiencing symptoms at some point
THD is primarily indicated for symptomatic grade II, III, and sometimes IV hemorrhoids that have failed conservative management
Its adoption is increasing due to its perceived lower morbidity compared to traditional hemorrhoidectomy.
Clinical Significance:
Symptomatic hemorrhoids can significantly impact a patient's quality of life due to pain, bleeding, itching, and discomfort
THD offers an effective treatment option that preserves the anal cushions, aims to minimize postoperative pain, and allows for a quicker return to daily activities compared to excisional hemorrhoidectomy
Understanding THD is crucial for colorectal surgeons and residents preparing for DNB and NEET SS examinations.
Indications
Indications:
Primary indications for THD include symptomatic internal hemorrhoids of grade II, III, and selected grade IV
These symptoms typically manifest as intermittent rectal bleeding, prolapse, pain, or discomfort that has not responded to conservative measures such as dietary modifications, fiber supplements, stool softeners, and topical treatments
It is particularly useful for prolapsing hemorrhoids where excisional techniques might lead to significant postoperative pain and functional deficits.
Contraindications:
Absolute contraindications are rare but include severe anal stenosis or significant proctitis
Relative contraindications may include active perianal infection, significant coagulopathy, or advanced malignancy of the anal canal or rectum
Patients with extensive external hemorrhoids or significant mucosal prolapse requiring significant debridement may be better candidates for other procedures.
Patient Selection:
Careful patient selection is paramount
Patients should have a thorough understanding of the procedure, its benefits, and potential risks
A detailed history and physical examination, including anoscopy, are essential to confirm the diagnosis and grade the hemorrhoids
Exclusion of other anorectal pathologies like anal fissures, fistulas, or inflammatory bowel disease is critical before proceeding with THD.
Preoperative Preparation
History And Examination:
Detailed history of bowel habits, bleeding, pain, and previous treatments is obtained
A digital rectal examination and anoscopy are performed to assess the grade and extent of hemorrhoids, rule out other pathology, and evaluate for anal tone and any stenosis.
Bowel Preparation:
Standard bowel preparation, similar to that for other anorectal procedures, is typically performed
This usually involves a clear liquid diet the day before surgery and oral laxatives to ensure an empty rectum
Antibiotic prophylaxis is generally recommended, often a single dose of a broad-spectrum antibiotic like a cephalosporin or fluoroquinolone, 30-60 minutes before incision.
Anesthesia:
THD can be performed under various anesthetic techniques, including spinal anesthesia, general anesthesia, or even local anesthesia with sedation
The choice of anesthesia is individualized based on patient factors, surgeon preference, and the complexity of the procedure
Postoperative pain management strategies should be discussed preoperatively.
Procedure Steps
Instrumentation:
The core instrument for THD is a specialized proctoscope with an integrated Doppler probe and a ligature system
The Doppler probe helps to identify the pulsating superior rectal arteries within the anal canal.
Arterial Identification:
After the anal canal is exposed, the proctoscope is advanced, and the Doppler probe is used to locate the superior rectal arteries
These are typically identified at the 6, 2, and 10 o'clock positions, correlating to the dentate line.
Arterial Ligation:
Once an artery is identified, a purse-string suture is placed distal to it, encircling the vessel and the hemorrhoidal tissue supplied by it
This suture is then tied securely, ligating the artery and pedicle
The hemorrhoidal prolapsed tissue is thus suspended superiorly.
Closure:
The purse-string suture is then usually tied, creating a "mucosal plication" that helps to pull the prolapsed hemorrhoidal tissue back into its normal anatomical position
The proctoscope is then rotated, and the process is repeated for other identified arteries, typically ligating 2-4 arteries per session.
Completion:
After all target arteries are ligated, the instrument is withdrawn
The procedure usually takes 20-40 minutes
Bleeding is typically minimal
Any significant external hemorrhoids may require a limited excision or other adjuncts.
Postoperative Care
Pain Management:
Postoperative pain is generally less severe than with traditional hemorrhoidectomy
Patients are usually managed with oral analgesics, including NSAIDs and acetaminophen
Sitting in a warm sitz bath several times a day can also provide relief and promote hygiene.
Wound Care:
As THD involves ligating arteries and suspending tissue rather than excising it, there are no open wounds in the anal canal to heal
Patients are advised to maintain good anal hygiene, and stool softeners are prescribed to ensure soft bowel movements and prevent straining.
Diet And Activity:
A high-fiber diet is encouraged to promote regular bowel movements
Patients are usually advised to avoid strenuous physical activity for the first 1-2 weeks postoperatively but can generally resume normal daily activities much sooner than after traditional hemorrhoidectomy
Follow-up appointments are scheduled to monitor healing and symptom resolution.
Complications
Early Complications:
Early complications are generally infrequent and mild
They can include mild postoperative pain, temporary urinary retention (especially after spinal anesthesia), urinary tract infection, bleeding (usually self-limiting), and perianal skin irritation
Minor wound infection at the external sphincter area is possible if any external hemorrhoidectomy was performed concurrently.
Late Complications:
Late complications are rare but can include recurrence of hemorrhoids (especially if indicated arteries were missed or if conservative measures are not maintained), anal stenosis (less common than with excisional techniques), fecal urgency or tenesmus, and chronic anal pain
Formation of a fistula is extremely rare
Thrombosis of external hemorrhoids can occur if they were present preoperatively.
Prevention Strategies:
Careful technique during arterial ligation, ensuring secure knots, and adequate mucosal plication are crucial to prevent recurrence
Meticulous patient selection and preoperative assessment to exclude contraindications are vital
Postoperative instructions regarding diet, hygiene, and avoiding straining are essential for optimal outcomes and preventing complications
Prompt management of any early signs of infection or excessive bleeding is also important.
Prognosis
Factors Affecting Prognosis:
Prognosis is generally good for appropriately selected patients
Factors influencing successful outcomes include the correct identification and ligation of all relevant superior rectal arteries, the degree of initial hemorrhoidal prolapse, and patient adherence to postoperative care and lifestyle modifications
Surgeon experience also plays a role.
Outcomes:
THD has demonstrated good short-term and long-term efficacy in reducing symptoms of bleeding and prolapse in grades II and III hemorrhoids, with success rates reported between 75% and 90% in various studies
Pain relief is typically significant, and patients often report a faster recovery compared to conventional hemorrhoidectomy.
Follow Up:
Regular follow-up is recommended to assess symptom resolution and detect any early signs of recurrence
Typically, patients are seen at 2-4 weeks postoperatively, and then again at 3-6 months
Long-term follow-up may be advised for patients with a history of significant hemorrhoidal disease or other risk factors for recurrence
Emphasis on continued high-fiber diet and hydration is crucial.
Key Points
Exam Focus:
THD is a minimally invasive procedure for symptomatic internal hemorrhoids (grades II-IV)
It involves Doppler-guided ligation of superior rectal arteries to reduce blood flow and prolapse
Key arteries are at 6, 2, and 10 o'clock positions
It preserves the anal cushions and has lower postoperative pain than excisional hemorrhoidectomy.
Clinical Pearls:
The Doppler probe is essential for identifying the pulsating arteries
Accurate placement of the purse-string suture distal to the artery and secure tying is crucial for efficacy
Consider combining with limited external hemorrhoidectomy for mixed hemorrhoids
Educate patients on long-term lifestyle changes to prevent recurrence.
Common Mistakes:
Failure to identify all significant superior rectal arteries, leading to recurrence
Inadequate or loose ligation of the artery, causing bleeding or failure to shrink hemorrhoidal tissue
Misinterpretation of Doppler signals
Performing THD for conditions where it is not indicated, such as significant thrombosed external hemorrhoids or anal fissures.