Hemorrhoids

External Hemorrhoids

The external hemorrhoidal plexus is a network of veins that run around the anus at the anal verge. The veins become symptomatic when they thrombose. Resolution of external hemorrhoid thrombosis may predispose to anal tags that are usually asymptomatic but are typically excised along with prolapsing internal hemorrhoids. Acute thrombosis of the external hemorrhoidal plexus is a painful condition that tends to follow straining, either during lifting, childbirth, or defecation. Affected patients are in considerable pain and have an edematous lump at the anal verge caused by the clot. Often the blue color of the clot confirms the diagnosis. Surgical excision of acutely thrombosed external hemorrhoids is warranted when the thrombosis is large, painful, and identified within 72 hours of onset. Sometimes the clot ulcerates through the skin and patients experience anal bleeding independent of bowel habits, with partial easing of the pain. This presentation is another indication for surgery. Small external hemorrhoidal thromboses are easily managed in the office setting with a local anesthetic and complete excision of the clot and vein, with or without skin closure. More extensive thromboses should be excised with use of a general anesthetic to allow careful planning of the excision and preservation of the anoderm.

Anatomy and Etiology of Internal Hemorrhoids

Internal hemorrhoids are vascular cushions lying above the dentate line under the mucosa of the low rectum. The classic orientation of the hemorrhoidal cushions is right anterior, right posterior, and left lateral, although intervening secondary hemorrhoidal complexes may blur this classic anatomy. The arterial blood supply, which contributes to the frequent symptom of bright red rectal bleeding, is derived from the superior rectal artery, a branch of the inferior mesenteric artery, the middle rectal arteries arising from the internal iliac arteries, and the inferior rectal arteries arising from the pudendal arteries. Above the dentate line the venous drainage enters the portal venous system, whereas below the dentate line it passes to the systemic venous system. This vascular anatomy creates the cushions that contribute to anal continence and can be damaged by excessive straining, leading to the prolapse and bleeding typical of symptomatic hemorrhoids.

An understanding of the stages of hemorrhoidal pathophysiology is the basis for developing a strategy for management of symptomatic hemorrhoids. The staging system is shown in Box 2-1 . At the earliest stage of disease, transudation of blood through thin-walled, damaged veins and/or arterioles presents primarily as painless bleeding and can be managed with astringents or local ablation of the vessels. Later, as the damage progresses to significant disruption of the mucosal suspensory ligament, a technique capable of relocating the prolapsing tissue to its normal location and fixing the tissue at that location will be required.

Clinical Evaluation

The typical constellation of hemorrhoidal symptoms includes bleeding, protrusion, and pain. However, only about one third of all patients with anorectal symptoms will actually have hemorrhoids as the cause of their symptoms. Hemorrhoidal bleeding, which typically occurs after bowel movements, is painless and visible as bright red blood either on the toilet paper or in the commode. The bleeding can become more severe as the hemorrhoids enlarge and are either partially or completely trapped in a prolapsed position. Patients with tight internal sphincters are prone to magnified hemorrhoidal symptoms because of the increased pressure in the anus. The history then addresses bowel habits, the frequency of straining upon defecation, recent changes in medications, diet, or lifestyle, and the presence of a family history of colorectal cancer. The patient should be asked about prior procedures performed to treat hemorrhoids, although the answer must be taken with a grain of salt unless it is supported by medical records.

Examination of the patient with hematochezia, although tailored by the age of the patient, should include sufficient investigations to rule out a proximal source of bleeding such as inflammatory bowel disease or neoplasia. Hemorrhoids should not be accepted as the cause of iron deficiency anemia because this cause is rare.

First, a careful digital examination of the anal canal and distal rectum should be performed, including palpation of the prostate in men. Inspection of the anus may reveal skin tags, bulging external hemorrhoidal cushions (clues to the presence of internal hemorrhoidal prolapse), or fourth-degree internal hemorrhoids. Other conditions may be present that mimic or co-exist with hemorrhoids, such as anal excoriation, anal neoplasms, condylomata, or fissure. If the patient does not have a fissure, an anoscopy is performed to determine the size and degree of prolapse of the hemorrhoids. Poking the cushions with a cotton-tipped swab gives an impression of the degree of redundancy and the suitability of the hemorrhoid for elastic band ligation. White plaques on the hemorrhoids (pseudoepitheliomatous hyperplasia) are an indication of chronic prolapse. Hemorrhoids should be classified as previously described to define the degree of mucosal irritation, prolapse, columns involved, and associated anal skin tags. If the patient has presented with bleeding, has an increased risk for colorectal cancer, or is at average risk but is overdue for screening, a colonoscopy is requested. No physical treatment should be performed without clearing the colon, because drop metastases from a cancer proximal to an anal canal wound can occur.

Nonexcisional Options