Current theories about the development of hemorrhoids consider the nature of anal “cushions.” Such cushions are aggregations of blood vessels (arterioles, venules, and arteriolar-venular communications), smooth muscle, and elastic connective tissue in the submucosa that normally reside in the left lateral, right posterolateral, and right anterolateral anal canal.36 Smaller discrete secondary cushions may reside between the main cushions. Hemorrhoids are likely the result of a sliding downward of these anal cushions. Hemorrhoids provide tissue to close the anal canal during rest. It appears that the disintegration of the anchoring and supporting connective tissue and the terminal fibers of the longitudinal muscle above the hemorrhoids allows these structures to slide distally.
Anal skin tags are discrete folds of skin located at the anal verge. These may be the end result of resolved thrombosed external hemorrhoids or, more rarely, may be associated with inflammatory bowel disease. Internal hemorrhoids reside above the dentate line and are covered by transitional and columnar epithelium (Fig. 39-13). First-degree internal hemorrhoids cause painless bleeding with defecation. Second-degree hemorrhoids protrude through the anal canal at the time of defecation but spontaneously reduce. Third-degree internal hemorrhoids protrude and bleed with defecation, but they must be manually reduced. Fourth-degree internal hemorrhoids are permanently fixed below the dentate line and cannot be manually reduced.
Location and types of hemorrhoids. (Redrawn, with permission, from Fry RD, Kodner IJ. Anorectal diseases. Clin Symp. 1985;37(6):2–32. Copyright 1985, Academy of Medical Sciences. Originally illustrated by John Craig, MD.)
External hemorrhoids consist of the dilated vascular plexus located below the dentate line and are covered by squamous epithelium. Mixed hemorrhoids are composed of elements of both internal and external hemorrhoids.
Evaluation of Internal Hemorrhoids
Even though internal hemorrhoids are the most common source of rectal bleeding, it is imperative that other causes be excluded. Because internal hemorrhoids cannot be detected by digital examination, diagnosis can only be made by anoscopy. It is mandatory that colonoscopy be performed in high-risk patients to exclude other sources of bleeding, such as carcinoma or proctitis (eg, for patients aged >40 years and those with a personal or family history of colorectal neoplasia or a change in bowel habits).
Regulation of diet and avoidance of prolonged straining at the time of defecation comprise the initial treatment of mild symptoms of bleeding and protrusion. Increasing the fiber content of the diet to at least 25–35 g daily with raw vegetables, fruits, whole-grain cereals, and hydrophilic bulk-forming agents can reduce and often alleviate all symptoms. If bleeding and protrusion persist, however, the hemorrhoids should be treated surgically.
Elastic ligation of the friable redundant hemorrhoidal tissue is quite satisfactory for first-, second- and third-degree hemorrhoids. The procedure is quite simple. The hemorrhoid is visualized with the aid of an anoscope and grasped with forceps. The redundant tissue is pulled into a double-sleeved cylinder on which there are two latex bands. The bands are discharged from the cylinder, and the hemorrhoidal bundle is ligated (Fig. 39-14).
Elastic ligation technique. (Redrawn, with permission, from Fry RD, Kodner IJ. Anorectal diseases. Clin Symp. 1985;37(6):2–32. Copyright 1985, Academy of Medical Sciences. Originally illustrated by John Craig, MD.)
Certain precautions, however, must be taken with this form of treatment. The ligatures must be placed at least 1–2 cm above the dentate line to avoid extreme discomfort. Ideally, the ligatures should be placed at the top of the hemorrhoidal cushion. About 25% of patients experience mild, dull anorectal discomfort lasting for 2–3 days following the procedure. Mild analgesics and warm baths are usually sufficient to relieve the discomfort. In about 1% of patients, brisk bleeding that may require suture ligation occurs when the necrotic tissue sloughs off at 7–10 days. About 2% of patients treated with ligation of the internal hemorrhoid develop thrombosis of an external hemorrhoid, which may cause considerable discomfort. Necrotizing pelvic or perineal sepsis is rare and almost always associated with immune compromise but must be immediately recognized in the setting of increased pain, fever, or urinary dysfunction. Treatment requires immediate examination under anesthesia for debridement of all necrotic tissue, intravenous antibiotics, and observation in the intensive care unit. Patients with poorly functioning neutrophils or reduced numbers of white blood cells for any reason should be treated with another method or at least warned of and observed for the occurrence of this potentially life-threatening complication.
Hemorrhoidal ligation is an office procedure, and no special preparation is required. Patients with a bleeding diathesis or with portal hypertension are not good candidates for ligation. Usually only one hemorrhoid is ligated on the first treatment visit. Ligations can be performed every 2–4 weeks until all symptoms of bleeding or prolapse are alleviated. The second ligation can be multiple if the first treatment is well tolerated. Other minimally invasive procedures such as infrared coagulation, diathermy coagulation, and ultrasound-guided vascular pedicle ligation achieve the same result with variable success and need for effort.
Although diet, bowel regulation, or elastic ligation will alleviate most symptoms of internal hemorrhoids, occasionally further surgical treatment may be needed. Excisional hemorrhoidectomy is indicated for large, mixed (combined internal/external) hemorrhoids that are not amenable to ligation because the ligature would have to incorporate pain-sensitive tissue at or below the dentate line.
Circular stapled hemorrhoidectomy is a newer technique indicated for the elective treatment of circumferential third- and fourth-degree hemorrhoids that are not permanently prolapsed due to scar.37 This involves placing a purse-string suture incorporating the mucosa of the anal canal with a stapled circumferential mucosectomy at a level 4–5 cm above the dentate line. This can be performed under regional anesthesia with minimal morbidity in experienced hands. Potential complications include bleeding if the staple line is incomplete, pain if the staple line is too close to the dentate line, rectovaginal fistula if the purse string captures the rectovaginal septum, complete closure of the rectum if the stapler and purse string are malpositioned, and return of symptoms if the purse string is incomplete.
Occasionally, the internal hemorrhoidal tissue may be incarcerated outside the anal canal, resulting in spasm of the anal sphincter, massive local edema, and severe pain. In such circumstances, the edematous tissue may be injected with a local anesthetic containing epinephrine. Dissipation of the edema by manual compression then can be achieved, allowing reduction in the prolapsed tissue. Observation and use of stool softeners with tub soaks usually allow the acute episode to resolve without an operation because the hemorrhoidal vessels have been naturally thrombosed. The thrombosed internal hemorrhoids will sclerose and may not require surgery. If symptoms persist or recur, a three-quadrant hemorrhoidectomy may then be necessary. If necrotic tissue is present at the time of acute thrombosis, emergent excisional hemorrhoidectomy is necessary. Care should be taken to preserve the anoderm. The patient should be kept in the hospital after the procedure until the pain is minimal and until spontaneous voiding is possible and to ensure resolution of any potential infection.
The mucosal component of mixed hemorrhoids occasionally can be treated by elastic ligation. Large symptomatic, nonreducing mixed hemorrhoids generally are treated by excisional hemorrhoidectomy. The patient is placed in the prone flexed position under local anesthesia using a perianal field block with 0.25% bupivacaine with or without epinephrine. The apex of the vascular pedicle is ligated first with a 3-0 chromic catgut suture. An elliptical excision incorporates the external and internal hemorrhoids from the perianal skin to the anorectal ring. The hemorrhoidal tissue is sharply dissected from the underlying internal sphincter (Fig. 39-15). The entire wound is then closed by running the apex chromic catgut suture to the distal perianal skin edge. The largest hemorrhoid is excised first, with care taken not to excise excessive tissue that may result in a stricture. If there is any concern of leaving an adequate anal aperture covered by normal anoderm, it is best to modify a planned three-quadrant hemorrhoidectomy and instead perform a two-quadrant hemorrhoidectomy and band the remaining internal component.
Excision technique for mixed hemorrhoids. (Redrawn, with permission, from Fry RD, Kodner IJ. Anorectal diseases. Clin Symp. 1985;37(6):2–32. Copyright 1985, Academy of Medical Sciences. Originally illustrated by John Craig, MD.)
Thrombosed External Hemorrhoids
The external venous plexus is located at the anal verge and encircles the anal canal. A segmental thrombus is confined to the anoderm and perianal skin and does not extend above the dentate line. The problem presents as a painful perianal mass. The overlying skin may be stretched to 2 cm or more. Pain usually peaks within 48 hours and generally becomes minimal after the fourth day. If untreated, the thrombus is absorbed within a few weeks. The pressure of the underlying clot will occasionally cause the adjacent skin to become necrotic, and the clot will be extruded through the area of necrosis. This is noted by the patient as rectal bleeding followed by relief of the anal pain. A partially extruded clot can be removed in the office to provide relief.
Treatment of thrombosed hemorrhoids is aimed at relief of the pain. If symptoms are minimal, mild analgesics, sitz baths, proper anal hygiene, and bulk-producing agents will suffice. However, if pain is severe, excision of the thrombosed hemorrhoid may be beneficial. Because numerous vessels usually are involved, it is necessary to excise the entire mass along with the overlying skin and subcutaneous tissue. The wound is left open without packing. Postoperative care consists of mild analgesics and warm sitz baths or showers.