Procedures for Benign Anorectal Disease

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CHAPTER 17 Procedures for Benign Anorectal Disease

Hooman Noorchashm, David J. Maron

HEMORRHOIDS

Case Study

A 45-year-old multiparous female presents to a general surgeon’s office complaining of intermittent painless bright red blood per rectum during bowel movements. She also notes anal discharge and perianal pruritis. She reports a long-standing history of constipation. Anoscopy is performed and shows redundant anorectal mucosa in the right anterolateral and right posterolateral positions.

BACKGROUND

Hemorrhoids are cushions of fibromuscular tissue that line the anal canal. Three main bundles of hemorrhoidal tissue are located at the right anterolateral, right posterolateral, and left lateral positions and play a role in anal continence. As it is used clinically, the term hemorrhoid connotes the pathologic engorgement of a cushion of hemorrhoidal tissue. Constipation, prolonged straining, and pregnancy may contribute to hemorrhoid development.

Hemorrhoids are broadly categorized as external or internal. External hemorrhoids develop distal to the dentate line and are associated with pain when they thrombose. Internal hemorrhoids develop proximal to the dentate line and are typically painless. Common presentations of internal hemorrhoids include bleeding and prolapse with defecation. The following classification system is used to describe internal hemorrhoids: (1) first-degree hemorrhoids are nonprolapsed, (2) second-degree hemorrhoids prolapse and spontaneously reduce, (3) third-degree hemorrhoids prolapse and must be digitally reduced, and (4) fourth-degree hemorrhoids are irreducible.

The dentate line is the junction between the columnar epithelium of the upper anal canal and the squamous epithelium of the lower anal canal, also known as the anoderm.

INDICATIONS FOR SURGERY

I. Failure of Medical Therapy: Hemorrhoids often improve with Sitz baths, avoidance of excessive straining, stool softeners, and fiber supplementation. Patients with symptomatic hemorrhoids that do not improve with conservative management are candidates for more aggressive treatment. First-, second-, and third-degree hemorrhoids refractory to medical treatment are often treated with rubber band ligation, which can be performed in the office. Extensive third- and fourth-degree hemorrhoids are rarely amenable to conservative management or rubber band ligation and are typically treated with hemorrhoidectomy.
II. Thrombosed External Hemorrhoids: Acute thrombosis of an external hemorrhoid may be associated with severe pain. Patients who present early after thrombosis (<72 hours) may benefit from incision and clot enucleation.

PREOPERATIVE EVALUATION

I. History: Internal hemorrhoids are typically painless and may cause bright red bleeding or prolapse with defecation. Patients with external hemorrhoids may complain of swelling and discomfort. In the absence of thrombosis, pain should not be attributed to hemorrhoids and alternative diagnoses should be sought.

COLORECTAL CANCER MUST ALWAYS BE EXCLUDED AS A SOURCE OF BLEEDING PER RECTUM.

II. Physical Examination: Physical examination of patients with hemorrhoids should include a digital rectal examination and anoscopy. In the absence of prolapse, anoscopic evaluation of internal hemorrhoids may show redundant anorectal mucosa. In patients who present with bleeding, endoscopic evaluation must be undertaken to exclude colorectal cancer.

Has your patient undergone colonoscopy?

COMPONENTS OF THE PROCEDURE AND APPLIED ANATOMY

Rubber band ligation can be performed in the office setting and is frequently used for the treatment of first-, second-, and some third-degree hemorrhoids. Traditional open and closed hemorrhoidectomy procedures are technically similar and lead to comparable outcomes. As its name implies, the closed technique involves closure of the defect created by hemorrhoid excision and is the approach most frequently used in the United States. Stapled hemorrhoidopexy is an increasingly popular alternative that may be associated with less postoperative pain than traditional hemorrhoidectomy.

I. Preoperative Considerations

A. Bowel preparation is administered preoperatively.
B. Antibiotics to cover gram-negative and anaerobic bacteria are administered preoperatively.
C. Rubber band ligation is often performed without anesthesia in the office setting. Hemorrhoidectomy and stapled hemorrhoidopexy may be performed under general or spinal anesthesia.

II. Patient Positioning and Preparation: The patient is placed in the prone jack-knife position (supine and flexed at the hips). The perianal region is prepared and draped.
III. Surgical Approach

A. Rubber band ligation:

1. A speculum is inserted into the anal canal and the hemorrhoidal bundles are identified.
2. With a band applicator, two rubber bands are applied to each hemorrhoidal cluster above the dentate line (Fig. 17-1).

image

Figure 17-1 Rubber band ligation of hemorrhoids. Rubber bands are loaded onto the applicator, which is introduced into the anal canal. The hemorrhoidal bundles are suctioned into the applicator and bands are applied.

(From Townsend CM, Beauchamp RD, Evers BM, Mattox KL [eds]: Sabiston Textbook of Surgery: The Biological Basis of Modern Surgical Practice, 17th ed. Philadelphia, Saunders, 2004.)

APPLICATION OF RUBBER BANDS BELOW THE DENTATE LINE IS ASSOCIATED WITH SEVERE PAIN BECAUSE THE ANODERM DISTAL TO THE DENTATE LINE IS INNERVATED BY SOMATIC PAIN FIBERS.

B. Closed hemorrhoidectomy:

1. A retractor is inserted into the anal canal, and the hemorrhoidal bundles are identified.
2. Enlarged hemorrhoidal tissues are excised with an elliptical incision. Care is taken to preserve the underlying muscle fibers of the anal sphincters.
3. When multiple bundles are excised, intervening bridges of anoderm are preserved to avoid subsequent stenosis.
4. After excision, defects are closed with absorbable suture (Fig. 17-2).

C. Stapled hemorrhoidopexy: A circular anal dilator/stapler is inserted into the anal canal. A purse-string suture is placed through the mucosa and submucosa of the anal canal, 3 to 4 cm above the dentate line, to draw the hemorrhoidal tissue into the stapling device. The stapler is fired to excise a 4-cm ring of rectal mucosa (Fig. 17-3).

image

Figure 17-2 Closed hemorrhoidectomy. A and B, The hemorrhoidal bundle is exposed and excised via an elliptical incision. Care is taken to preserve the underlying sphincter muscles. C, After excision, the defect is closed.

(From Townsend CM, Beauchamp RD, Evers BM, Mattox KL [eds]: Sabiston Textbook of Surgery: The Biological Basis of Modern Surgical Practice, 17th ed. Philadelphia, Saunders, 2004.)

image

Figure 17-3 Stapled hemorrhoidopexy. A suture is placed through the mucosa and submucosa (A), which are drawn into the stapling device (B). The stapler is fired to excise a ring of hemorrhoidal tissue (C).

(From Cameron J: Current Surgical Therapy, 8th ed. Philadelphia, Mosby, 2004.)

POSTOPERATIVE COURSE

Hemorrhoidectomy is typically performed as an outpatient procedure. Patients may experience substantial postoperative pain and should be prescribed analgesic agents and stool softeners. Use of a doughnut cushion may improve comfort when sitting.

COMPLICATIONS

I. Perineal sepsis is a well-described complication of hemorrhoidectomy. Severe postprocedure pain, inability to void, and fever may herald the onset of sepsis and should prompt emergent evaluation.
II. Bleeding is common after hemorrhoidectomy. Bleeding is usually self-limited, but occasionally requires operative intervention.
III. Urinary retention is common after hemorrhoidectomy. Although it is typically self-limited, temporary placement of a urinary catheter is sometimes necessary.
IV. Stricture formation after hemorrhoidectomy has been associated with circumferential excision of anoderm. Preservation of intervening islands of anoderm between excised bundles may lessen the risk of stricture formation.

ANORECTAL ABSCESS

Case Study

A 35-year-old male presents to a surgeon’s office complaining of perianal pain and purulent discharge for the last 2 days. His symptoms preclude him from sitting or walking comfortably. One month earlier, the patient underwent incision and drainage of a perirectal abscess and began a course of oral antibiotics.

BACKGROUND

The majority of anorectal abscesses result from infection originating in the anal crypts located at the dentate line. Abscesses are classified as perianal (60%), ischiorectal (20%), intersphincteric (10%), or supralevator (9%), depending on their location (Fig. 17-4). Deep postanal space abscesses represent a particular challenge. The deep postanal space is protected from view by the sacrum, and abscesses originating in this cavity may track circumferentially into the ischiorectal, intersphincteric, or supralevator space before they are diagnosed (Fig. 17-5). This pattern of spread results in what is known as a horseshoe abscess.

image

Figure 17-4 Common anatomic locations of anorectal abscesses: perianal (a), ischiorectal (b), intersphincteric (c), and supralevator (d).

(From Noble J [ed]: Textbook of Primary Care Medicine, 3rd ed. Philadelphia, Mosby, 2001.)

image

Figure 17-5 Lateral view of the deep postanal space.

(From Cameron J: Current Surgical Therapy, 8th ed. Philadelphia, Mosby, 2004.)

Anorectal abscesses are often caused by normal intestinal tract flora (e.g., Escherichia coli and Bacteroides splanchnicus). Alternatively, infections of the perianal skin caused by gram-positive organisms may evolve into perianal abscesses.

INDICATIONS FOR SURGERY

Anorectal abscesses should be treated with prompt surgical drainage. Septic and immunosuppressed patients should be taken to the operating room emergently. Although some abscesses may be drained at the bedside, drainage in the operating room allows for better patient positioning, exposure, and anesthesia.

PREOPERATIVE EVALUATION

I. History: Patients with anorectal abscesses may complain of pain, fevers, chills, and purulent discharge. A history of recurrent abscesses and immunosuppression (e.g., HIV/AIDS and diabetes) should be elicited.
II. Physical Examination: Although digital rectal examination should be performed when tolerated by the patient, examination under anesthesia (EUA) is required to define the anatomy of the anorectal abcess. An EUA is typically combined with drainage of the abcess.

A. Superficial abscesses (i.e., perianal and ischiorectal abscesses) typically present with tenderness, fluctuance, and erythema.
B. Perianal abscesses are found adjacent to the anal verge.
C. Ischiorectal abscesses are typically larger and present with a buttock mass.
D. Intersphincteric and supralevator abscesses may present with tenderness and fullness within the anal canal.

III. Laboratory Studies: Leukocytosis is frequently noted on complete blood count.
IV. Imaging Studies: Computed tomography (CT) scanning or magnetic resonance imaging (MRI) of the pelvis may be helpful in delineating the anatomy of an abscess, particularly when examination findings are equivocal.

COMPONENTS OF THE PROCEDURE AND APPLIED ANATOMY

I. Preoperative Considerations

A. Broad-spectrum antibiotics are administered preoperatively, when the diagnosis of abscess is made.
B. In the case of superficial abscesses, local anesthetics are used to infiltrate the surrounding area. Drainage of complex abscesses may be performed under conscious sedation or general, epidural, or spinal anesthesia.

II. Patient Positioning and Preparation: The patient is placed in the prone jack-knife position. The perianal region is prepared and draped.
III. Surgical Approach

A. Perianal and ischiorectal abscesses

1. Perianal and ischiorectal abscesses are superficial and readily drained by incising the skin overlying the abscess cavity. Both are typically associated with appreciable fluctuance and are therefore readily localized by external examination.
2. An elliptical or cruciate incision is made over the area of maximal fluctuance. A finger or instrument is inserted into the abscess cavity to break any loculations. The abscess cavity is then irrigated with sterile saline. The skin edges are trimmed to prevent rapid closure of the incision and ensure ongoing drainage.
3. When draining an ischiorectal abscess, care must be taken not to violate the levator muscle (which lies superior to the ischiorectal fossa) because this can result in the development of a supralevator abscess.

THE LEVATOR MUSCLE SHOULD NOT BE VIOLATED DURING DRAINAGE OF AN ISCHIORECTAL ABSCESS.

B. Intersphincteric abscesses

1. Intersphincteric abscesses are generally located posteriorly. Unlike perianal and ischiorectal abscesses, they are not usually evident on external examination. However, a tender mass is sometimes appreciable on digital rectal examination.
2. To access the intersphincteric space, a posterior transverse incision is made in the anoderm. The plane between the internal and external sphincters is developed bluntly, and the abscess cavity is opened and irrigated with sterile saline.
3. A mushroom catheter is placed in the cavity and sutured in place.

Failure to leave a drainage catheter in the intersphincteric space after abscess drainage results in a high rate of recurrence.

C. Supralevator abscesses: Supralevator abscesses may develop from upward extension of intersphincteric or ischiorectal abscesses. Abscesses that develop from extension of infections of the intersphincteric space are drained directly through the rectal mucosa, whereas abscesses that communicate with ischiorectal abscesses are drained through the ischiorectal fossa (as described under “Perianal and Ischiorectal Abscesses”).
D. Deep postanal space abscesses: To access the deep postanal space, a posterior transverse incision is made in the anoderm. The plane between the internal and external sphincters is developed bluntly. Dissection is continued superiorly through the puborectalis muscle to enter the deep postanal space. A drainage catheter placed in the abscess cavity and sutured in place.

POSTOPERATIVE COURSE

After drainage of anorectal abscesses, patients are prescribed analgesia, local anesthetics, stool softeners, and mild laxatives. Antibiotic therapy should be continued during the postoperative period, particularly in immunosuppressed patients (e.g., those with HIV/AIDS or diabetes).

COMPLICATIONS

I. Recurrence rates after abscess drainage may be as high as 30%. Incomplete drainage of a deep postanal space abscess is one example of a technical error, which can result in recurrent ischiorectal abscesses.
II. Rates of fistula formation after drainage of anorectal abscesses are also high (40%), and careful postoperative follow-up is essential.

ANORECTAL FISTULAE

Case Study

A 32-year-old male presents to a surgeon’s office complaining of intermittent purulent anal discharge. His medical history is significant for inflammatory bowel disease and recurrent anorectal abscesses. He is afebrile and has a normal white blood cell count. On examination, several draining perianal sinuses are noted anteriorly.

BACKGROUND

A fistula is defined as the abnormal communication between two epithelial-lined surfaces. Most anorectal fistulae begin as abscesses of the anal crypts. The offending organisms are almost always enteric bacteria. A communication between the epithelial surface of the perianal region and the infected anal crypt may form spontaneously or iatrogenically after surgical drainage. Anorectal fistulae are classified by the anatomic relationship of the tract to the anal sphincters as intersphincteric, trans-sphincteric, suprasphincteric, or extrasphincteric (Fig. 17-6).

image

Figure 17-6 Anatomic classification of anorectal fistulae. Intersphincteric fistulae (type I) are confined to the intersphincteric plane. Trans-sphincteric fistulae (type II) traverse the external sphincter. Suprasphincteric fistulae (type III) traverse the levator muscle above the sphincter. Extrasphincteric fistulae (type IV) form a communication between the rectum and perianal skin, external to the sphincters. The puborectalis muscle is identified by cross-hatching and forms the superior boundary of the external sphincter.

(From Parks AG, Gordon PH, Hardcastle JD: A classification of fistula-in-ano. Br J Surg 63:5, 1976. Copyright British Journal of Surgery Society Ltd. Reproduced with permission. Permission is granted by John Wiley & Sons Ltd. on behalf of the BJSS Ltd.)

Spontaneous anorectal fistulae are caused by inflammatory bowel disease, congenital desmoids, chronic pelvic sepsis, tuberculosis, and actinomycosis.

The path of fistulae generally follows Goodsall’s rule (Fig. 17-7), which states that posterior external openings communicate with the anal canal at the posterior midline through a curved tract, whereas anterior external openings communicate directly with the closest anal crypt along a straight path. Multiple anterior external openings typically have separate internal openings. Multiple posterior external openings usually have a common posterior midline internal opening.

image

Figure 17-7 Goodsall’s rule. Posterior external openings communicate with the anal canal at the posterior midline through a curved tract (A). Anterior external openings directly communicate with the closest anal crypt along a straight path (B). The long anterior fistula is an exception to the rule and may also communicate with the anal canal through an internal opening at the posterior midline.

(From Schrock TR: Benign and malignant disease of the anorectum. In Fromm O [ed]: Gastrointestinal Surgery. New York, Churchill Livingstone, 1985, p 612.)

INDICATIONS FOR SURGERY

Failure of Medical Management: Persistent anorectal fistulae require operative management. Surgical treatment of anorectal fistulae in the setting of inflammatory bowel disease is optimally undertaken when the inflammatory process is relatively quiescent.

PREOPERATIVE EVALUATION

I. History: Patients typically report a history of anorectal abscesses. A history of a predisposing medical condition (e.g., inflammatory bowel disease) should also be elicited.
II. Physical Examination: Proctoscopy and sigmoidoscopy are useful in identifying the location of the internal fistula openings and evaluating for the presence of underlying pathology, respectively. These evaluations are usually undertaken at the time of surgery. Additionally, methylene blue or hydrogen peroxide can be injected into the external opening to identify the internal fistula opening when it is not readily apparent.
III. Imaging Studies: Magnetic resonance imaging is sometimes useful for delineating the anatomy of complex fistulae.

COMPONENTS OF THE PROCEDURE AND APPLIED ANATOMY

I. Preoperative Considerations

A. Bowel preparation is administered preoperatively.
B. Broad-spectrum antibiotics are often administered in the perioperative setting.
C. Fistulae may be approached under general, epidural, or spinal anesthesia.

II. Patient Positioning and Preparation: The patient is placed in the prone jack-knife position. The perianal region is prepared and draped.
III. Surgical Approach

A. The surgical approach to a fistula tract depends on whether it traverses the anal sphincters or the puborectalis muscle. Fistulae that do not traverse these muscles are typically treated with a simple fistulotomy. Those involving the sphincter muscle are treated with seton fistulotomy, fibrin glue, an anal fistula plug, or a mucosal advancement flap to preserve anal continence.
B. Fistulotomy

1. A malleable probe is gently inserted into the fistula tract.
2. The skin and epithelium overlying the tract are divided with cautery. If more than a few muscle fibers are encountered in the course of this dissection, the procedure is converted to a seton fistulotomy.

C. Seton fistulotomy (cutting seton)

1. Soft rubber tubing or heavy silk suture (i.e., a seton) is threaded through a malleable probe and passed through the fistula tract.
2. The perianal skin and only the most superficial fibers of the internal sphincter overlying the fistula tract are typically divided.
3. The seton is held in place while the probe is removed from the tract. The ends of the seton are tied together to create a loop through the tract.
4. The seton may be intermittently tightened in the office setting to allow for gradual division and healing of the sphincter (i.e., a cutting seton).

D. Fibrin Glue and Anal Fistula Plug: The fistula tract is irrigated and injected with either fibrin glue or a decellularized porcine collagen plug. Both are intended to occlude the fistula tract. The collagen plug also serves as a “bioscaffold” on which scar tissue may form.
E. Mucosal advancement flap

1. The fistula tract is excised from the external opening to the sphincter muscles.
2. The internal opening is visualized with the aid of a retractor.
3. A mucosal flap incorporating the internal fistula opening is raised off the underlying internal sphincter muscle. The opening of the fistula is sharply excised from the flap.
4. The flap is pulled down and sutured in place over the exposed muscle.

POSTOPERATIVE COURSE

Adequate analgesia, antibiotic coverage, and local hygiene are critical to a successful outcome. After seton fistulotomy, patients should be examined at regular intervals. The seton may be tightened biweekly to gradually divide the involved portion of sphincter muscle. By the second or third postoperative visit, the seton has usually divided through the sphincter muscle and may have fallen out spontaneously.

COMPLICATIONS

I. Recurrence is common after surgery, particularly in the setting of an under-lying inflammatory process. Careful postoperative follow-up in the office is required.
II. Incontinence may result from dissection of the anal sphincter muscles. This complication is more common in the setting of complex fistulae.

FISSURE IN ANO

Case Study

A 30-year-old female presents to a surgeon’s office 3 months postpartum from an uneventful vaginal delivery. She complains of intense anal pain during defecation, accompanied by mild bleeding on the toilet paper. On physical examination, a small, shallow anal ulcer is seen at the anterior midline of the anal margin.

BACKGROUND

Anal fissures are caused by a split in the highly sensitive squamous epithelium of the anal canal below the dentate line. Primary fissures are typically associated with constipation and local trauma. Ninety percent of primary fissures occur in the posterior midline. However, postpartum fissures sometimes occur in the anterior aspect of the anal canal during childbirth. Secondary fissures are complications of AIDS, anal tuberculosis, or Crohn’s disease. These fissures may occur away from the midline.

INDICATIONS FOR SURGERY

Failure of Medical Therapy: Anal fissures are initially treated medically. The majority of patients with anal fissures respond to stool softeners, bulking agents, and topical anesthetics. An increase in dietary fiber intake by at least 15 g/day, along with topical lidocaine therapy, is often effective in healing acute fissures. Topical nitroglycerine or diltiazem may also be used in an effort to relax the internal anal sphincter and increase blood flow. Failure of medical management and fissure recurrence are indications for surgical therapy. The main objective of surgery is to reduce the hyperactivity of the internal anal sphincter.

The relapse rate after medical management of chronic anal fissures approaches 50% at 12 months.

PREOPERATIVE EVALUATION

I. History: Patients with fissures typically complain of pain and bleeding with defecation. Most patients report a history of chronic constipation.
II. Physical Examination: Fissures are usually evident on examination as “boat-shaped” defects with edematous margins. Transverse fibers of the internal anal sphincter are sometimes seen at the ulcer base. Digital examination may cause intense pain and is not recommended.

Is your patient’s fissure located at the midline?

III. Endoscopy: Before surgical therapy for the treatment of anal fissure, a complete examination under anesthesia should be undertaken. The sensitivity of this evaluation may be enhanced by proctosigmoidoscopy to rule out underlying anorectal pathology.

COMPONENTS OF THE PROCEDURE AND APPLIED ANATOMY

I. Preoperative Considerations

A. Bowel preparation is sometimes administered preoperatively, particularly if the patient is to undergo endoscopic evaluation.
B. Sphincterotomy may be performed under general or spinal anesthesia.

II. Patient Positioning and Preparation: The patient is placed in the prone jack-knife position. The perianal region is prepped and draped.
III. Surgical Approach

A. The main objective of surgery for anal fissures is to reduce the hyperactivity of the internal anal sphincter through division of its fibers.
B. Lateral subcutaneous internal sphincterotomy

1. Lidocaine containing epinephrine is injected into the submucosal and intersphincteric planes.
2. The surgeon’s index finger is placed into the anal canal.
3. A small blade is inserted laterally into the intersphincteric groove, and the hypertrophied fibers of the internal sphincter are divided, avoiding division of the anal mucosa (Fig. 17-8).

C. Open internal sphincterotomy

1. Lidocaine containing epinephrine is injected into the submucosal and intersphincteric plane of the anal wall.
2. The lateral aspect of the anal canal is exposed with a speculum.
3. A 1- to 1.5-cm incision is made through the anoderm below the dentate line.
4. The anal mucosa is dissected away from the internal sphincter.
5. The fibers of the internal sphincter are divided (Fig. 17-9).

image

Figure 17-8 Lateral subcutaneous internal sphincterotomy. The fibers of the internal sphincter are sharply divided against an index finger without dividing the anal mucosa.

(From Cameron J: Current Surgical Therapy, 8th ed. Philadelphia, Mosby, 2004.)

image

Figure 17-9 Open lateral sphincterotomy. The anoderm is incised, exposing the fibers of the internal sphincter (A and B). The fibers are sharply divided (C).

(From Cameron J: Current Surgical Therapy, 8th ed. Philadelphia, Mosby, 2004.)

POSTERIOR SPHINCTEROTOMY AND FISSURE EXCISION ARE NEVER WARRANTED BECAUSE THIS APPROACH IS ASSOCIATED WITH CHRONIC INCONTINENCE.

POSTOPERATIVE COURSE

Surgery for anal fissures is typically performed in the outpatient setting. Patients are prescribed analgesics, local anesthetics, and stool softeners before discharge.

COMPLICATIONS

I. Bleeding occurs in 2% to 3% of patients after surgery for anal fissures.
II. Fecal incontinence occurs in 3% to 5% of patients and can last for up to 2 or 3 months, but is usually self-limited.

SUGGESTED READINGs

Cameron JL. Current Surgical Therapy, 8th ed. Philadelphia: Mosby; 2004.

Kleighley MRB. Anorectal disorders. In: Fischer JE, Bland KI, editors. Mastery of Surgery. 5th ed. Philadelphia: Lippincott Williams & Wilkins; 2007:1609-1627.

Nelson H. Anus. In: Townsend CM, Beauchamp RD, Evers BM, Mattox KL, editors. Sabiston Textbook of Surgery: The Biological Basis of Modern Surgical Practice. 17th ed. Philadelphia: Saunders; 2004:1483-1512.

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