Emborrhoid: Rectal Artery Embolization for Hemorrhoid Disease

Hemorrhoids are a common anorectal disease, defined as the enlargement and symptomatic prolapse of the hemorrhoidal cushions. It affects millions of people around the world and is a major medical and socioeconomic problem.

In recent years, an improved anatomical understanding and the need to develop minimally invasive approaches have led to the development of the Doppler-guided hemorrhoidal artery ligation (DG-HAL) procedure as an effective treatment for hemorrhoids. ¹

The DG-HAL procedure uses dedicated equipment and involves the identification of hemorrhoidal arteries using Doppler ultrasound, and their ligation to decrease the flow of arterial blood to the hemorrhoidal cushions. This procedure is performed via the transanal route under local anesthesia.

This technique has several advantages: it leaves the hemorrhoidal tissue in place, preserves anal continence, and is significantly less painful and less prone to complications than open surgery, allowing patients to return to work sooner. ²

Based on the underlying principles of this technique, we have developed the “emborrhoid” embolization technique, in which endovascular occlusion of the arteries from the distal branches of the inferior mesenteric artery (IMA) is performed. Our preliminary results for this technique have been reported in other publications. ^{3 4 5 6 7 8 9 10}

Compared with DG-HAL, the endovascular approach offers the advantage of identifying all the hemorrhoidal arterial branches, recognizing anatomical variations, and ensuring effective occlusion of the target branches, which could improve therapeutic results. No comparative study between the two techniques has yet been performed.

The aim of this article is to describe our team's current methods and results for the emborrhoid technique as the main alternative treatment for patients with hemorrhoids.

Physiopathology and Anatomy

Internal hemorrhoidal disease is defined as hypertrophy of the hemorrhoidal vascular plexuses, causing chronic symptoms, of which bleeding is the main one. Previous studies have defined hemorrhoids as a “corpus cavernosum recti (CCR)” corresponding to a complex vascular structure made up of a dense network of arteriovenous anastomoses. ¹¹ The main physiological role that hemorrhoids play in bowel continence is explained by the presence, in the normal state, of multiple arteriovenous shunts, forming an actual “cushion” at the anorectal junction. ¹² The result is a densification of arterioles and venous lakes as well as a multiplication of arteriovenous shunts, causing an increase in the superior rectal arterial (SRA) flow, reminiscent of the natural history of an arteriovenous malformation. The long-term consequences are congestive symptoms associating prolapse and bleeding. Various transperineal Doppler ultrasound studies have confirmed vascular hypertrophy and hemorrhoidal arterial hyperflow in patients with chronic bleeding. ¹³

The vascularization of the hemorrhoidal plexus most often comes from the SRAs, which are the terminal branches of the IMA and in a non-negligible proportion from the middle rectal arteries (MRAs), for up to 36% of patients with bilateral MRA in 12% of cases. ^{14 15 16} Vascularization from the lower rectal arteries appears to be much rarer. It supplies the entire rectum, the lining of the anal canal, and the internal hemorrhoidal bundles. Vascularization of the SRA was described as early as the 1970s and 1980s in cadavers.

SRAs originate from a single trunk and plunge downward and forward inside the pelvic mesocolon to reach the posterior wall of the rectum. They divide into right and left branches, then into an anterior and posterior branch. There are, on average, four SRAs from which the feeder arteries of the rectal wall originate. The terminal branches of the SRAs directly supply the hemorrhoidal plexuses at the anorectal junction.

The MRAs arise from the internal iliac artery (IIA) and supply the rectal and genital areas. ¹⁷ They most often originate from the internal pudendal artery (60%), the inferior gluteal artery (21.3%), or a common trunk between the inferior gluteal artery and the internal pudendal artery (16.2%). Much less frequently, they can originate from the obturator artery (2.5%). ¹⁴

The inferior rectal artery (IRA) arises from the IIA and supplies the anal sphincters, the levator ani muscle, and the external hemorrhoids ( Fig. 1 ).

Fig. 1.

Illustration of the common anatomical variation of the vascularization of the corpus cavernosum recti (CCR). Most of the time, there are only hypertrophic SRAs ( a ). Occasionally present are hypertrophic MRAs with or without hypertrophic SRA ( b ). CIA, common iliac artery; IMA, inferior mesenteric artery; IPA, internal pudendal artery; IRA, inferior rectal artery; MRAs, middle rectal arteries; SRAs, superior rectal arteries.

Patient Selection

Hemorrhoidal disease is a common problem. There are a variety of options, surgical and nonsurgical, for the treatment of hemorrhoids. Most hemorrhoidal problems can be managed without surgery.

As a first step, hygienic and dietary measures are recommended to reverse the pathophysiological mechanism of hemorrhoidal disease and to reduce symptoms. Patients should also be counseled on changing their lifestyle. ¹⁸

Topical treatments can also be prescribed, though they tend to not be effective. Rubber band ligation is generally useful for treating hemorrhoidal bleeding that has not improved after first-line, nonoperative treatment. Embolization of the rectal arteries is used only in the event of symptomatic hemorrhoidal disease that has an impact on the patient's quality of life.

An initial, preoperative clinical examination by a proctologist is essential to assess the stage of the hemorrhoidal disease and to check for any anorectal cancer. A multidisciplinary team of interventional radiologists and proctologists is involved in the selection and monitoring of patients. Candidates for rectal artery embolization most often have chronic grade I to III internal hemorrhoids, according to Goligher's classification ( Table 1 ). Fourth-degree hemorrhoids can be treated if their symptoms are clinically relevant and other surgical procedures are contraindicated. However, embolization of the rectal arteries will not alleviate the normal aging process or any positional pelvic disorders. During the initial consultation, the impact on the daily life of the patient suffering from chronic hemorrhoidal disease is assessed using a special scale, the “hemorrhoid bleeding score ¹⁹ ” ( Table 2 ).

Table 1. Goligher's classification.

Grade	Description
Grade I	Hemorrhoids without prolapse
Grade II	Prolapse on defecation with spontaneous reduction
Grade III	Prolapse on defecation requiring manual reduction
Grade IV	Irreducible hemorrhoids

Table 2. Hemorrhoidal bleeding score.

Frequency	Never	0
	< 1/day or at each bowel movement	1
	≥ 1/day or at each bowel movement	2
Type	Never	0
	Wiping with or without underwear	1
	Toilet bowl	2
Anemia	Never	0
	Iron deficiency without anemia	1
	Without transfusion	2
	With transfusion	3
Discomfort	Little or no discomfort	0
	Moderate discomfort	1
	Extreme or permanent discomfort	2
Overall score		–

We also use the visual analog scale (VAS) to measure pain levels and the SF-36 Health Assessment Questionnaire. General contraindications for the emborrhoid treatment are patients with anorectal cancer and contraindications for conventional angiography, such as allergies to iodinated contrast media or renal failure.

Imaging Protocol

Abdominopelvic computed tomographic (CT) angiography before embolization is not performed systematically but can be useful to identify atheromatous stenosis (of the IMA or of the common femoral artery) to prevent any treatment failure. It is particularly relevant for patients with multiple cardiovascular risk factors or a history of cardiovascular disease. The ability to identify anatomical variations (MRA hypertrophy) could help in the planning of the procedure (and reduce the time and risk of failure or reembolization; Figs. 2 and 3 ).

Fig. 2.

Pelvic CTA 3D ( a ) and digital subtraction angiography ( b ) showing superior rectal arteries (SRAs) (arrows). SRAs arise from the inferior mesenteric artery and feed mainly the corpus cavernosum (asterisk).

Fig. 3.

Pelvic CTA, maximum intensity projection ( a ) and 3D images ( b ) showing a hypertrophic right middle rectal artery (MRA). MRA arises from the pudendal artery and feeds mainly the corpus cavernosum recti with a blush (yellow arrow).

It can also be useful in revealing other diseases such as varicose veins as a result of portal hypertension which are not, strictly speaking, hemorrhoids and which require specific treatment. ^{20 21}

Rectal magnetic resonance imaging (MRI) and ultrasound ²² are not currently used but are being studied to assess their therapeutic value.

The Emborrhoid Technique

The embolization of the rectal arteries to treat hemorrhoids requires a good understanding of pelvic vascular anatomy.

Patients are admitted to hospital on the day of the operation. The operation is performed under local anesthesia on an outpatient basis in the interventional radiology department using the unilateral femoral or radial approach under strict aseptic conditions. The radial route can be an interesting alternative. Developed by interventional cardiologists, it is becoming more and more popular in interventional radiology. ²³ It results in a reduction in local complications related to the puncture, a better vascular approach in the event of unfavorable anatomical or advanced atheromatous lesions, as well as a shorter period of postoperative monitoring, with the patient able to get out of bed at Hour 2.

The emborrhoid technique does not require any pre- or intraoperative medication or specific “intestinal” preparation except in the case of a transradial approach when heparin at a therapeutic dose (50 U/kg or 5,000 U) and vasodilator (Nitroglycerin 200 μg, verapamil 2.5 mg, heparin 2,000 IU intra-arterial) is administered before the skin is punctured, which reduces the risk of thrombosis.

Identifying and Catheterizing the Superior Rectal Artery

The femoral or radial artery is accessed using the Seldinger technique under local anesthetic. A 4FR (1.40 mm) Simmons catheter, with an inverted U -shaped curve, is inserted at the origin of the IMA for selective angiography. The best way to catheterize the IMA is by using an oblique right anterior angle of 25 degrees.

Angiography of the IMA ( Fig. 4 ) is performed:

Fig. 4.

Frontal digital subtraction angiography showing a modal anatomy of the inferior mesenteric artery (asterisk), superior rectal arteries (yellow arrow), sigmoid arteries (red arrow), and left colic arteries (blue arrow).

• Using digital subtraction angiography and an automatic injector at a dose of 20 cc to 3 cc/sec of nonionic iodinated contrast medium, or

• Cone-beam CT (CBCT) (20 mL at a flow rate of 3 mL/s with a delay of 4 seconds and a rotation of 40 degree/s, with a contrast medium diluted to 50%) can be very useful in identifying and catheterizing any target arteries, reducing the procedure time.

The hemorrhoidal arteries can be easily identified, appearing twisted and vertical, projecting from the pubic bone ( Fig. 5 ).

Fig. 5.

A 49-year-old man with internal hemorrhoids treated by embolization of the upper rectal arteries. Angiography before embolization without ( a ) and with digital subtraction ( b ). Visualized are the common superior rectal artery (SRA) trunk (asterisk), superior left rectal artery (white arrow), and terminal branches of the SRA that supply internal hemorrhoids in the pubic bone (yellow arrow).

In most cases, a microcatheter, less than or equal to 2.4 FR, is used to progress as far as possible up to the branches of the SRA to the CCR. A selective distal contrast medium is injected to show the CCR. During this selective injection, digital subtraction angiograms (DSAs) reveal the MRAs by retrograde opacification when they are of sufficient size ( Fig. 6 ).

Fig. 6.

Selective injection of the digital subtraction angiography in the left superior rectal artery makes it possible to unmask by retrograde opacification in the left middle rectal artery that is hypertrophic (yellow arrow).

This angiographic diagnostic step is essential because it will make it possible to define the anatomical type of vascularization and to carry out an exhaustive embolization, reducing the risk of reembolization. The creation of such a roadmap can be very useful to guide the catheterization of the small branches of the SRA. In the event of vasospasm, nitrates (1 mg of Risordan in situ, which can be repeated if there is good blood pressure tolerance) can be used. Another good strategy is to switch to the contralateral side while waiting for the vasospasm to stop. If catheterization of the IMA is not possible due to atheromatous stenosis, the search for an anastomosis between the SRA and the MRA should be done directly by catheterization of the IIA. Catheterization via the arc of Riolan can also be considered. A software can be used to help clinicians locate the route to use and can help them carry out the embolization procedure with confidence.

Embolization

Various embolic agents can be used. Based on our clinical practice, we use fibered coils to obstruct the distal branches of the SRA. The fibered coils allow efficient occlusion of the target vessels without the risk of intestinal ischemia linked to the embolization of the distal but not terminal branches. The highest efficacy rate in hemorrhoid embolization has been reported with the use of a combination of microparticles and microcoils. ¹⁰ This embolic agent can provide more distal occlusion of the target vessels. Recently, a study on the use of microspheres confirmed these results, with a clinical success rate of 93%. ²² However, the rate of minor complications was high, close to 50%, consisting of small ischemic ulcerations of the anorectal junction. So, the evidence regarding the optimal choice of embolic agent remains equivocal, with insufficient evidence to recommend either embolization with microparticles or micro coils as the best option.

MRAs can be embolized in the same way ( Fig. 2 ).

Success rates of this technique in the literature have been very high, ranging from 93 to 100%. ^{3 5 6 7 8 9 10} The goal of embolization is to close all branches of the SRA just above the pubic branch, as close as possible to the recti network of the corpora cavernosa ( Figs. 7 and 8 ).

Fig. 7.

Catheterization of the ostium of the inferior mesenteric artery using a Simmons 4FR catheter ( a , b ) and then 3D arteriography of the superior rectal artery identifying the target branches and allowing a progression of the microcatheter to the left anterior branch ( c , d ). Occlusion of the left anterior branch and the other branches using micro-coils ( e , f ). At the end of the procedure, no residual branch is opacified under the pubic symphysis.

Fig. 8.

Catheterization of the ostium of the inferior mesenteric artery (arrow) using a Simmons 4FR catheter ( a ), then arteriography of the superior rectal artery identifying the target branches (arrow) ( b ), evidence of a large left middle rectal artery (arrow) ( c ), and catheterization of the left middle rectal artery (asterisk)( d ).

Embolization is performed until the “end point” is reached (i.e., there is neither any opacification of the distal branches of the SRA nor any opacification of the terminal branches in the projection of the hemorrhoids).

Angiography of the IIA is now performed on a systematic basis to look for a large MRA that feeds the hemorrhoids. A contralateral or ipsilateral catheterization is performed to position a diagnostic catheter in the hypogastric artery.

A three-dimensional CBCT is often performed in the IIA in accordance with the following protocol: 48 mL at a flow rate of 6 mL/s, with a delay of 2 seconds and a rotation of 40 degree/s, with a contrast medium diluted to 50%. The MRA is the opacified branch coming from the IIA to the CCR. Three-dimensional CBCT makes it possible to highlight all the different branches of the IIA with a CBCT spatial resolution, coupled with the resolution of an intra-arterial injection ( Fig. 9 ).

Fig. 9.

Cone-beam CT after opacification of the right internal iliac artery ( a ) revealing the left middle rectal artery supplying part of the CCR projecting from the pubis. Route planning after VR reconstruction of the right middle rectal artery (arrow) ( b ).

Technical and Clinical Success, Complications, and Follow-up

The patient is discharged from hospital after a 6-hour postoperative surveillance period by a specialist nurse and after a clinical examination by the interventional radiologist in the case of a femoral puncture or 2 hours after a radial approach.

The emborrhoid technique is not a painful procedure, and patients are usually given oral hydration and nonopioid pain relievers, as required. After embolization, the patients are followed up by the interventional radiologist, the proctologist, or the surgeon, to evaluate how their symptoms have changed (using the HBS, Goligher's classification, and a quality-of-life score) and to record any complications approximately 3 months after the procedure. The success rates of this technique in the literature are very high, ranging from 93 to 100%. ^{5 6 7 8 9 10}

We consider it to have been successful when the bilateral hypertrophic arteries, SRA, and MRA have been embolized. Clinical success is defined as an improvement in clinical scores after embolization, with no severe complications.

The emborrhoid technique is safe and effective. No serious complications or adverse events during rectal artery embolization have been found. As with any other visceral embolization, patients may experience symptoms such as nausea, vomiting, fever in the absence of infection, or pelvic pain syndrome, especially when particles are used. More specifically, a hematoma, infection, or pseudoaneurysm may be observed at the puncture site, but are rare complications. In the event of early recurrence, generally linked to incomplete embolization, a second embolization procedure may be considered. Fig. 10 illustrates the flowchart used by our team for hemorrhoidal artery embolization.

Fig. 10.

Diagram of hemorrhoidal disease diagnosis and treatment. HBS, hemorrhoid bleeding score.

Conclusion

The experience we have gained now allows us to standardize this embolization technique. It is essential to embolize all the upper and middle rectal arteries that have a significant caliber to prevent a recurrence. We now recommend the use of coils to prevent any ischemic risk. Even though the reduction in symptoms is sometimes poor, patient satisfaction is very good for this minimally invasive procedure.