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Anorectal Diseases
Any patient with anal/perianal symptoms requires a careful history and physical, including a digital rectal
examination. Other studies such as defecography, manometry, CT scan, MRI, contrast enema, endoscopy, or
exam under anesthesia may be required to arrive at an accurate diagnosis.
Hemorrhoids
Hemorrhoids are cushions of submucosal tissue containing venules, arterioles, and smooth-muscle fibers that are
located in the anal canal (see Fig. 28-4). Three hemorrhoidal cushions are found in the left lateral, right anterior,
and right posterior positions. Hemorrhoids are thought to function as part of the continence mechanism and aid in
complete closure of the anal canal at rest. Because hemorrhoids are a normal part of anorectal anatomy, treatment
is only indicated if they become symptomatic. Excessive straining, increased abdominal pressure, and hard stools
increase venous engorgement of the hemorrhoidal plexus and cause prolapse of hemorrhoidal tissue. Outlet
bleeding, thrombosis, and symptomatic hemorrhoidal prolapse may result.
External hemorrhoids are located distal to the dentate line and are covered with anoderm. Because the anoderm is
richly innervated, thrombosis of an external hemorrhoid may cause significant pain. It is for this reason that
external hemorrhoids should not be ligated or excised without adequate local anesthetic. A skin tag is redundant
fibrotic skin at the anal verge, often persisting as the residual of a thrombosed external hemorrhoid. Skin tags are
often confused with symptomatic hemorrhoids. External hemorrhoids and skin tags may cause itching and
difficulty with hygiene if they are large. Treatment of external hemorrhoids and skin tags are only indicated for
symptomatic relief.
Internal hemorrhoids are located proximal to the dentate line and covered by insensate anorectal mucosa. Internal
hemorrhoids may prolapse or bleed, but rarely become painful unless they develop thrombosis and necrosis
(usually related to severe prolapse, incarceration, and/or strangulation). Internal hemorrhoids are graded
according to the extent of prolapse. First-degree hemorrhoids bulge into the anal canal and may prolapse beyond
the dentate line on straining. Second-degree hemorrhoids prolapse through the anus but reduce spontaneously.
Third-degree hemorrhoids prolapse through the anal canal and require manual reduction. Fourth-degree
hemorrhoids prolapse but cannot be reduced and are at risk for strangulation.
Combined internal and external hemorrhoids straddle the dentate line and have characteristics of both internal
and external hemorrhoids. Hemorrhoidectomy is often required for large, symptomatic, combined hemorrhoids.
Postpartum hemorrhoids result from straining during labor, which results in edema, thrombosis, and/or
strangulation. Hemorrhoidectomy is often the treatment of choice, especially if the patient has had chronic
hemorrhoidal symptoms. Portal hypertension was long thought to increase the risk of hemorrhoidal bleeding
because of the anastomoses between the portal venous system (middle and upper hemorrhoidal plexuses) and the
systemic venous system (inferior rectal plexuses). It is now understood that hemorrhoidal disease is no more
common in patients with portal hypertension than in the normal population. Rectal varices, however, may occur
and may cause hemorrhage in these patients. In general, rectal varices are best treated by lowering portal venous
pressure. Rarely, suture ligation may be necessary if massive bleeding persists. Surgical hemorrhoidectomy
should be avoided in these patients because of the risk of massive, difficult-to-control variceal bleeding.
Treatment
Medical Therapy
Bleeding from first- and second-degree hemorrhoids often improves with the addition of dietary fiber, stool
softeners, increased fluid intake, and avoidance of straining. Associated pruritus may often improve with
improved hygiene. Many over-the-counter topical medications are desiccants and are relatively ineffective for
treating hemorrhoidal symptoms.
Rubber Band Ligation
Persistent bleeding from first-, second-, and selected third-degree hemorrhoids may be treated by rubber band
ligation.
Mucosa located 1 to 2 cm proximal to the dentate line is grasped and pulled into a rubber band applier. After
firing the ligator, the rubber band strangulates the underlying tissue, causing scarring and preventing further
bleeding or prolapse (Fig. 28-30). In general, only one or two quadrants are banded per visit. Severe pain will
occur if the rubber band is placed at or distal to the dentate line where sensory nerves are located. Other
complications of rubber band ligation include urinary retention, infection, and bleeding. Urinary retention occurs
in approximately 1% of patients and is more likely if the ligation has inadvertently included a portion of the
internal sphincter. Necrotizing infection is an uncommon, but life-threatening complication. Severe pain, fever,
and urinary retention are early signs of infection and should prompt immediate evaluation of the patient usually
with an exam under anesthesia. Treatment includes débridement of necrotic tissue, drainage of associated
abscesses, and broad-spectrum antibiotics. Bleeding may occur approximately 7 to 10 days after rubber band
ligation, at the time when the ligated pedicle necroses and sloughs. Bleeding is usually self-limited, but persistent
hemorrhage may require exam under anesthesia and suture ligation of the pedicle.
FIG. 28-30.
Rubber band ligation of internal hemorrhoids. The mucosa just proximal to the internal hemorrhoids is banded.
[Reproduced with permission from Schwartz SI, Shires GT, Spencer FC (eds): Principles of Surgery. 5th ed.
New York: McGraw-Hill, 1989, p 1303.]
Infrared Photocoagulation
Infrared photocoagulation is an effective office treatment for small first- and second-degree hemorrhoids. The
instrument is applied to the apex of each hemorrhoid to coagulate the underlying plexus. All three quadrants may
be treated during the same visit. Larger hemorrhoids and hemorrhoids with a significant amount of prolapse are
not effectively treated with this technique.
Sclerotherapy
The injection of bleeding internal hemorrhoids with sclerosing agents is another effective office technique for
treatment of first-, second-, and some third-degree hemorrhoids. One to 3 mL of a sclerosing solution (5-phenol in
olive oil, sodium morrhuate, or quinine urea) are injected into the submucosa of each hemorrhoid. Few
complications are associated with sclerotherapy, but infection and fibrosis have been reported.
Excision of Thrombosed External Hemorrhoids
Acutely thrombosed external hemorrhoids generally cause intense pain and a palpable perianal mass during the
first 24 to 72 hours after thrombosis. The thrombosis can be effectively treated with an elliptical excision
performed in the office under local anesthesia. Because the clot is usually loculated, simple incision and drainage
is rarely effective. After 72 hours, the clot begins to resorb, and the pain resolves spontaneously. Excision is
unnecessary, but sitz baths and analgesics are often helpful.
Operative Hemorrhoidectomy
A number of surgical procedures have been described for elective resection of symptomatic hemorrhoids. All are
based on decreasing blood flow to the hemorrhoidal plexuses and excising redundant anoderm and mucosa.
Closed Submucosal Hemorrhoidectomy
The Parks or Ferguson hemorrhoidectomy involves resection of hemorrhoidal tissue and closure of the wounds
with absorbable suture. The procedure may be performed in the prone or lithotomy position under local, regional,
or general anesthesia. The anal canal is examined and an anal speculum inserted. The hemorrhoid cushions and
associated redundant mucosa are identified and excised using an elliptical incision starting just distal to the anal
verge and extending proximally to the anorectal ring. It is crucial to identify the fibers of the internal sphincter
and carefully brush these away from the dissection in order to avoid injury to the sphincter. The apex of the
hemorrhoidal plexus is then ligated and the hemorrhoid excised. The wound is then closed with a running
absorbable suture. All three hemorrhoidal cushions may be removed using this technique; however, care should
be taken to avoid resecting a large area of perianal skin in order to avoid postoperative anal stenosis (Fig. 28-31).
FIG. 28-31.
Technique of closed submucosal hemorrhoidectomy. A. The patient is in prone jackknife position. B. A Fansler
anoscope is used for exposure. C. A narrow ellipse of anoderm is excised. D. A submucosal dissection of the
hemorrhoidal plexus from the underlying anal sphincter is performed. E. Redundant mucosa is anchored to the
proximal anal canal and the wound is closed with a running absorbable suture. F. Additional quadrants are
excised to complete the procedure. [Reproduced with permission from Schwartz SI, Shires GT, Spencer FC
(eds): Principles of Surgery. 5th ed. New York: McGraw-Hill, 1989, p 1304.]
Open Hemorrhoidectomy
This technique, often called the Milligan and Morgan hemorrhoidectomy, follows the same principles of excision
described above, but the wounds are left open and allowed to heal by secondary intention.
Whitehead's Hemorrhoidectomy
Whitehead's hemorrhoidectomy involves circumferential excision of the hemorrhoidal cushions just proximal to
the dentate line. After excision, the rectal mucosa is then advanced and sutured to the dentate line. While some
surgeons still use the Whitehead hemorrhoidectomy technique, most have abandoned this approach because of the
risk of ectropion (Whitehead's deformity).
Stapled Hemorrhoidectomy
Stapled hemorrhoidectomy has been proposed as an alternative surgical approach. 81–83 Unlike excisional
hemorrhoidectomy, stapled hemorrhoidectomy does not aim to excise redundant hemorrhoidal tissue. Instead,
stapled hemorrhoidectomy removes a short circumferential segment of rectal mucosa proximal to the dentate line
using a circular stapler. This effectively ligates the venules feeding the hemorrhoidal plexus and fixes redundant
mucosa higher in the anal canal. Critics suggest that this technique is only appropriate for patients with large,
bleeding, internal hemorrhoids, and is ineffective in management of external or combined hemorrhoids. Although
stapled hemorrhoidectomy has not been widely accepted at this time, it remains a promising new technique.
Complications of Hemorrhoidectomy
Postoperative pain following excisional hemorrhoidectomy requires analgesia usually with oral narcotics.
Nonsteroidal anti-inflammatory drugs, muscle relaxants, topical analgesics, and comfort measures, including sitz
baths, are often useful as well. Several studies show that stapled hemorrhoidectomy is associated with a
significant decrease in postoperative pain. Other complications are similar to those seen with excisional
hemorrhoidectomy. Urinary retention is a common complication following hemorrhoidectomy and occurs in 10 to
50% of patients. The risk of urinary retention can be minimized by limiting intraoperative and perioperative
intravenous fluids, and by providing adequate analgesia. Pain can also lead to fecal impaction. Risk of impaction
may be decreased by preoperative enemas or a limited mechanical bowel preparation, liberal use of laxatives
postoperatively, and adequate pain control. While a small amount of bleeding, especially with bowel movements,
is to be expected, massive hemorrhage can occur after hemorrhoidectomy. Bleeding may occur in the immediate
postoperative period (often in the recovery room) as a result of inadequate ligation of the vascular pedicle. This
type of hemorrhage mandates an urgent return to the operating room where suture ligation of the bleeding vessel
will often solve the problem. Bleeding may also occur 7 to 10 days after hemorrhoidectomy when the necrotic
mucosa overlying the vascular pedicle sloughs. While some of these patients may be safely observed, others will
require an exam under anesthesia to ligate the bleeding vessel or to oversew the wounds if no specific site of
bleeding is identified. Infection is uncommon after hemorrhoidectomy; however, necrotizing soft-tissue infection
can occur with devastating consequences. Severe pain, fever, and urinary retention may be early signs of
infection. If infection is suspected, an emergent examination under anesthesia, drainage of abscess, and/or
débridement of all necrotic tissue are required.
Long-term sequelae of hemorrhoidectomy include incontinence, anal stenosis, and ectropion (Whitehead's
deformity). Many patients experience transient incontinence to flatus, but these symptoms are usually short-lived
and few patients have permanent fecal incontinence. Anal stenosis may result from scarring after extensive
resection of perianal skin. Ectropion may occur after a Whitehead's hemorrhoidectomy. This complication is
usually the result of suturing the rectal mucosa too far distally in the anal canal and can be avoided by ensuring
that the mucosa is sutured at or just above the dentate line.
Anal Fissure
A fissure in ano is a tear in the anoderm distal to the dentate line. The pathophysiology of anal fissure is thought
to be related to trauma from either the passage of hard stool or prolonged diarrhea. A tear in the anoderm causes
spasm of the internal anal sphincter, which results in pain, increased tearing, and decreased blood supply to the
anoderm. This cycle of pain, spasm, and ischemia contributes to development of a poorly healing wound that
becomes a chronic fissure. The vast majority of anal fissures occur in the posterior midline. Ten to 15% occur in
the anterior midline. Less than 1% of fissures occur off midline.
Symptoms and Findings
Anal fissure is extremely common. 84,85 Characteristic symptoms include tearing pain with defecation and
hematochezia (usually described as blood on the toilet paper). Patients may also complain of a sensation of
intense and painful anal spasm lasting for several hours after a bowel movement. On physical examination, the
fissure can often be seen in the anoderm by gently separating the buttocks. Patients are often too tender to tolerate
digital rectal examination, anoscopy, or proctoscopy. An acute fissure is a superficial tear of the distal anoderm
and almost always heals with medical management. Chronic fissures develop ulceration and heaped-up edges
with the white fibers of the internal anal sphincter visible at the base of the ulcer. There is often an associated
external skin tag and/or a hypertrophied anal papilla internally. These fissures are more challenging to treat and
may require surgery. A lateral location of a chronic anal fissure may be evidence of an underlying disease such as
Crohn's disease, human immunodeficiency virus, syphilis, tuberculosis, or leukemia. If the diagnosis is in doubt
or there is suspicion of another cause for the perianal pain such as abscess or fistula, an examination under
anesthesia may be necessary.
Treatment
Therapy focuses on breaking the cycle of pain, spasm, and ischemia thought responsible for development of
fissure in ano. First-line therapy to minimize anal trauma includes bulk agents, stool softeners, and warm sitz
baths. The addition of 2% lidocaine jelly or other analgesic creams can provide additional symptomatic relief.
Nitroglycerin ointment (0.2%) has been used locally to improve blood flow but often causes severe headaches. 86
Both oral and topical diltiazem have also been used to heal fissures and may have fewer side effects than topical
nitrates. 87 Newer agents, such as arginine (a nitric oxide donor) and topical bethanechol (a muscarinic agonist),
have also been used to treat fissures. Medical therapy is effective in most acute fissures, but will heal only
approximately 50 to 60% of chronic fissures.
Botulinum toxin causes temporary muscle paralysis by preventing acetylcholine release from presynaptic nerve
terminals. Injection of botulinum toxin has been proposed as an alternative to surgical sphincterotomy for chronic
fissure. Although there is limited experience with this approach, results appear to be superior to other medical
therapy, and complications such as incontinence are rare. However, healing is slower than after sphincterotomy
and recurrence may be more common. 88
Surgical therapy has traditionally been recommended for chronic fissures that have failed medical therapy, and
lateral internal sphincterotomy is the procedure of choice for most surgeons. 89 The aim of this procedure is to
decrease spasm of the internal sphincter by dividing a portion of the muscle. Approximately 30% of the internal
sphincter fibers are divided laterally by using either an open (Fig. 28-32) or closed (Fig. 28-33) technique.
Healing is achieved in more than 95% of patients by using this technique and most patients experience immediate
pain relief. Recurrence occurs in less than 10% of patients and the risk of incontinence (usually to flatus) ranges
from 5 to 15%.
FIG. 28-32.
Open lateral internal sphincterotomy for fissure in ano. [Reproduced with permission from Schwartz SI, Shires
GT, Spencer FC (eds): Principles of Surgery. 5th ed. New York: McGraw-Hill, 1989, p 1304.]
FIG. 28-33.
Closed lateral internal sphincterotomy for fissure in ano. [Reproduced with permission from Schwartz SI, Shires
GT, Spencer FC (eds): Principles of Surgery. 5th ed. New York: McGraw-Hill, 1989, p 1305.]
Anorectal Sepsis and Cryptoglandular
Anorectal Sepsis and Cryptoglandular Abscess
Relevant Anatomy
The majority of anorectal suppurative disease results from infections of the anal glands (cryptoglandular
infection) found in the intersphincteric plane. Their ducts traverse the internal sphincter and empty into the anal
crypts at the level of the dentate line. Infection of an anal gland results in the formation of an abscess that enlarges
and spreads along one of several planes in the perianal and perirectal spaces. The perianal space surrounds the
anus and laterally becomes continuous with the fat of the buttocks. The intersphincteric space separates the
internal and external anal sphincters. It is continuous with the perianal space distally and extends cephalad into
the rectal wall. The ischiorectal space (ischiorectal fossa) is located lateral and posterior to the anus and is
bounded medially by the external sphincter, laterally by the ischium, superiorly by the levator ani, and inferiorly
by the transverse septum. The ischiorectal space contains the inferior rectal vessels and lymphatics. The two
ischiorectal spaces connect posteriorly above the anococcygeal ligament but below the levator ani muscle,
forming the deep postanal space. The supralevator spaces lie above the levator ani on either side of the rectum
and communicate posteriorly. The anatomy of these spaces influences the location and spread of cryptoglandular
infection (Fig. 28-34).
FIG. 28-34.
Anatomy of perianorectal spaces. A. Anterior view and (B) lateral view. [Reproduced with permission from
Schwartz SI, Shires GT, Spencer FC (eds): Principles of Surgery. 5th ed. New York: McGraw-Hill, 1989, pp
1298 and 1299.]
As an abscess enlarges, it spreads in one of several directions. A perianal abscess is the most common
manifestation and appears as a painful swelling at the anal verge. Spread through the external sphincter below the
level of the puborectalis produces an ischiorectal abscess. These abscesses may become extremely large and may
not be visible in the perianal region. Digital rectal exam will reveal a painful swelling laterally in the ischiorectal
fossa. Intersphincteric abscesses occur in the intersphincteric space and are notoriously difficult to diagnose,
often requiring an examination under anesthesia. Pelvic and supralevator abscesses are uncommon and may
result from extension of an intersphincteric or ischiorectal abscess upward, or extension of an intraperitoneal
abscess downward (Fig. 28-35).
FIG. 28-35.
Pathways of anorectal infection in perianal spaces. [Reproduced with permission from Schwartz SI, Shires GT,
Spencer FC (eds): Principles of Surgery. 5th ed. New York: McGraw-Hill, 1989, p 1299.]
Diagnosis
Severe anal pain is the most common presenting complaint. Walking, coughing, or straining can aggravate the
pain. A palpable mass is often detected by inspection of the perianal area or by digital rectal examination.
Occasionally, patients will present with fever, urinary retention, or life-threatening sepsis. The diagnosis of a
perianal or ischiorectal abscess can usually be made with physical exam alone (either in the office or in the
operating room). However, complex or atypical presentations may require imaging studies such as CT or MRI to
fully delineate the anatomy of the abscess.
Treatment
Anorectal abscesses should be treated by drainage as soon as the diagnosis is established. If the diagnosis is in
question, an examination under anesthesia is often the most expeditious way both to confirm the diagnosis and to
treat the problem. Delayed or inadequate treatment may occasionally cause extensive and life-threatening
suppuration with massive tissue necrosis and septicemia. Antibiotics are only indicated if there is extensive
overlying cellulitis or if the patient is immunocompromised, has diabetes mellitus, or has valvular heart disease.
Antibiotics alone are ineffective at treating perianal or perirectal infection.
Perianal Abscess
Most perianal abscesses can be drained under local anesthesia in the office, clinic, or emergency room. Larger,
more complicated abscesses may require drainage in the operating room. A cruciate skin and subcutaneous
incision is made over the most prominent part of the abscess and the "dog ears" are excised to prevent premature
closure. No packing is necessary and sitz baths are started the next day (Fig. 28-36).
FIG. 28-36.
Technique of drainage of perianal abscess. [Reproduced with permission from Schwartz SI, Shires GT, Spencer
FC (eds): Principles of Surgery. 5th ed. New York: McGraw-Hill, 1989, p 1300.]
Ischiorectal Abscesses
An ischiorectal abscess causes diffuse swelling in the ischiorectal fossa that may involve one or both sides,
forming a "horseshoe" abscess. Simple ischiorectal abscesses are drained through an incision in the overlying
skin. Horseshoe abscesses require drainage of the deep postanal space and often require counterincisions over one
or both ischiorectal spaces (Fig. 28-37).
FIG. 28-37.
Drainage of horseshoe abscess. The deep postanal space is entered, incising the anococcygeal ligament. Counter
drainage incisions are made for each limb of the ischiorectal space. [Reproduced with permission from Schwartz
SI, Shires GT, Spencer FC (eds): Principles of Surgery. 5th ed. New York: McGraw-Hill, 1989, p 1300.]
Intersphincteric Abscess
Intersphincteric abscesses are notoriously difficult to diagnose because they produce little swelling and few
perianal signs of infection. Pain is typically described as being deep and "up inside" the anal area, and is usually
exacerbated by coughing or sneezing. The pain is so intense that it usually precludes a digital rectal examination.
The diagnosis is made based upon a high index of suspicion and usually requires an examination under
anesthesia. Once identified, an intersphincteric abscess can be drained through a limited, usually posterior,
internal sphincterotomy.
Supralevator Abscess
This type of abscess is uncommon and can be difficult to diagnose. Because of its proximity to the peritoneal
cavity, supralevator abscesses can mimic intra-abdominal conditions. Digital rectal examination may reveal an
indurated, bulging mass above the anorectal ring.
It is essential to identify the origin of a supralevator abscess prior to treatment. If the abscess is secondary to an
upward extension of an intersphincteric abscess, it should be drained through the rectum. If it is drained through
the ischiorectal fossa, a complicated, suprasphincteric fistula may result. If a supralevator abscess arises from the
upward extension of an ischiorectal abscess, it should be drained through the ischiorectal fossa. Drainage of this
type of abscess through the rectum may result in an extrasphincteric fistula. If the abscess is secondary to intraabdominal disease, the primary process requires treatment and the abscess is drained via the most direct route
(transabdominally, rectally, or through the ischiorectal fossa).
Perianal Sepsis in the Immunocompromised Patient
The immunocompromised patient with perianal pain presents a diagnostic dilemma. Because of leukopenia, these
patients may develop serious perianal infection without any of the cardinal signs of inflammation. While broadspectrum antibiotics may cure some of these patients, an exam under anesthesia should not be delayed because of
neutropenia. An increase in pain or fever, and/or clinical deterioration mandates an exam under anesthesia. Any
indurated area should be incised and drained, biopsied to exclude a leukemic infiltrate, and cultured to aid in the
selection of antimicrobial agents.
Necrotizing Soft-Tissue Infection of the Perineum
Necrotizing soft-tissue infection of the perineum is a rare, but lethal, condition. Most of these infections are
polymicrobial and synergistic. The source of sepsis is commonly an undrained or inadequately drained
cryptoglandular abscess or a urogenital infection. Occasionally, these infections may be encountered
postoperatively (e.g., after inguinal hernia repair). Immunocompromised patients and diabetic patients are at
increased risk.
Physical examination may reveal necrotic skin, bullae, or crepitus. Patients often have signs of systemic toxicity
and may be hemodynamically unstable. A high index of suspicion is necessary because perineal signs of severe
infection may be minimal and prompt surgical intervention can be lifesaving.
Surgical débridement of all nonviable tissue is required to treat all necrotizing soft-tissue infections. Multiple
operations may be necessary to ensure that all necrotic tissue has been resected. Broad-spectrum antibiotics are
frequently employed, but adequate surgical débridement remains the mainstay of therapy. Colostomy may be
required if extensive resection of the sphincter is required, or if stool contamination of the perineum makes
wound management difficult. Despite early recognition and adequate surgical therapy, the mortality of
necrotizing perineal soft-tissue infections remains approximately 50%.
Fistula in Ano
Drainage of an anorectal abscess results in cure for about 50% of patients. The remaining 50% develop a
persistent fistula in ano. The fistula usually originates in the infected crypt (internal opening) and tracks to the
external opening, usually the site of prior drainage. The course of the fistula can often be predicted by the
anatomy of the previous abscess.
While the majority of fistulas are cryptoglandular in origin, trauma, Crohn's disease, malignancy, radiation, or
unusual infections (tuberculosis, actinomycosis, and chlamydia) may also produce fistulas. A complex, recurrent,
or nonhealing fistula should raise the suspicion of one of these diagnoses.
Diagnosis
Patients present with persistent drainage from the internal and/or external openings. An indurated tract is often
palpable. While the external opening is often easily identifiable, identification of the internal opening may be
more challenging. Goodsall's rule can be used as a guide in determining the location of the internal opening (Fig.
28-38). In general, fistulas with an external opening anteriorly connect to the internal opening by a short, radial
tract. Fistulas with an external opening posteriorly track in a curvilinear fashion to the posterior midline.
However, exceptions to this rule often occur if an anterior external opening is greater than 3 cm from the anal
margin. Such fistulas usually track to the posterior midline. Fistulas are categorized based upon their relationship
to the anal sphincter complex and treatment options are based upon these classifications. An intersphincteric
fistula tracks through the distal internal sphincter and intersphincteric space to an external opening near the anal
verge (Fig. 28-39A). A transsphincteric fistula often results from an ischiorectal abscess and extends through
both the internal and external sphincters (Fig. 28-39B). A suprasphincteric fistula originates in the
intersphincteric plane and tracks up and around the entire external sphincter (Fig. 28-39C). An extrasphincteric
fistula originates in the rectal wall and tracks around both sphincters to exit laterally, usually in the ischiorectal
fossa (Fig. 28-39D).
FIG. 28-38.
Goodsall's rule to identify the internal opening of fistulas in ano. [Reproduced with permission from Schwartz SI,
Shires GT, Spencer FC (eds): Principles of Surgery. 5th ed. New York: McGraw-Hill, 1989, p 1305.]
FIG. 28-39.
The four major categories of fistula in ano (left side of drawings) and the usual operative procedure to correct the
fistula (right side of drawings). A. Intersphincteric fistula with simple low tract. B. Uncomplicated
transsphincteric fistula. C. Uncomplicated suprasphincteric fistula. D. Extrasphincteric fistula secondary to anal
fistula. [Reproduced with permission from Gordon PH, Nivatvongs S (eds): Principles and Practice of Surgery
for the Colon, Rectum and Anus, 2nd ed. New York: Marcel Dekker, Inc., 1999, pp 256–260.]
Treatment
The goal of treatment of fistula in ano is eradication of sepsis without sacrificing continence. Because fistulous
tracks encircle variable amounts of the sphincter complex, surgical treatment is dictated by the location of the
internal and external openings and the course of the fistula. The external opening is usually visible as a red
elevation of granulation tissue with or without concurrent drainage. The internal opening may be more difficult to
identify. Injection of hydrogen peroxide or dilute methylene blue may be helpful. Care must be taken to avoid
creating an artificial internal opening (thus often converting a simple fistula into a complex fistula).
Simple intersphincteric fistulas can often be treated by fistulotomy (opening the fistulous tract), curettage, and
healing by secondary intention (see Fig. 28-39A). "Horseshoe" fistulas usually have an internal opening in the
posterior midline and extend anteriorly and laterally to one or both ischiorectal spaces by way of the deep
postanal space. Treatment of a transsphincteric fistula depends upon its location in the sphincter complex. Fistulas
that include less than 30% of the sphincter muscles can often be treated by sphincterotomy without significant
risk of major incontinence (see Fig. 28-39B). High transsphincteric fistulas, which encircle a greater amount of
muscle, are more safely treated by initial placement of a seton (see below). Similarly, suprasphincteric fistulas are
usually treated with seton placement (see Fig. 28-39C). Extrasphincteric fistulas are rare, and treatment depends
upon both the anatomy of the fistula and its etiology. In general, the portion of the fistula outside the sphincter
should be opened and drained. A primary tract at the level of the dentate line may also be opened if present.
Complex fistulas with multiple tracts may require numerous procedures to control sepsis and facilitate healing.
Liberal use of drains and setons is helpful. Failure to heal may ultimately require fecal diversion (see Fig. 28-
39D). Complex and/or nonhealing fistulas may result from Crohn's disease, malignancy, radiation proctitis, or
unusual infection. Proctoscopy should be performed in all cases of complex and/or nonhealing fistulas to assess
the health of the rectal mucosa. Biopsies of the fistula tract should be taken to rule out malignancy.
A seton is a drain placed through a fistula to maintain drainage and/or induce fibrosis. Cutting setons consist of a
suture or a rubber band that is placed through the fistula and intermittently tightened in the office. Tightening the
seton results in fibrosis and gradual division of the sphincter, thus eliminating the fistula while maintaining
continuity of the sphincter. A noncutting seton is a soft plastic drain (often a vessel loop) placed in the fistula to
maintain drainage. The fistula tract may subsequently be laid open with less risk of incontinence because scarring
prevents retraction of the sphincter. Alternatively, the seton may be left in place for chronic drainage. Higher
fistulas may be treated by an endorectal advancement flap (see below). Fibrin glue has also been used to treat
persistent fistulas with variable results
Hemorrhoidectomy for Thrombosed External Hemorrhoids
THOMAS J. ZUBER, M.D., Saginaw Cooperative Hospital, Saginaw, Michigan
External hemorrhoids represent distended vascular tissue in the anal canal distal to the
dentate line. Persons with thrombosed external hemorrhoids usually present with pain
on standing, sitting or defecating. Acutely tender, thrombosed external hemorrhoids
can be surgically removed if encountered within the first 72 hours after onset.
Hemorrhoidectomy is performed through an elliptic incision over the site of
thrombosis with removal of the entire diseased hemorrhoidal plexus in one piece.
Caution must be exercised to avoid cutting into the muscle sphincter below the
hemorrhoidal vessels. Infection after suture closure is rare secondary to the rich
vascular network in the anal area. Stool softeners must be prescribed postoperatively
to help prevent tearing at the suture line. Training and experience in general and skin
surgery are necessary before the physician attempts this procedure unsupervised. (Am
Fam Physician 2002;65:1629-32,1635-6,1639,1641-2. Copyright© 2002 American
Academy of Family Physicians.)
Office Procedures
forms on
hemorrhoidectomy
for thrombosed
external hemorrhoids
are provided on pages
1635, 1636 and 1639.
A patient
information handout
on hemorrhoidectomy
is provided on page
1641.
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External hemorrhoids usually develop over time and may result from straining with stools, childbirth, lengthy car
trips or prolonged sitting, constipation or diarrhea. External hemorrhoids represent distended vascular tissue in the
anal canal distal (outside) to the dentate line (the junction between the rectal mucosa and the specialized skin of
the anal canal, called the anoderm). External hemorrhoids are covered by anoderm and perianal skin richly
innervated with somatic pain fibers. Diseases affecting the anal canal or the external hemorrhoidal vessels can be
extremely painful.
A simple incision and removal of
thrombosis, as opposed to
hemorrhoidectomy, is associated with a
External hemorrhoids often develop in healthy young persons and
significant rate of rethrombosis.
may suddenly become thrombosed. Persons with thrombosed
external hemorrhoids usually present with pain on standing, sitting
or defecating. The thrombosis is slowly absorbed by the body
during the course of several weeks. A resolving thrombosis may erode through the skin and produce bleeding or
drainage.
Acutely swollen and tender thrombosed external hemorrhoids can be surgically removed during the first 72 hours
after onset. After 72 hours, the discomfort of the procedure often exceeds the relief provided by the surgery. Some
patients still chose to undergo late surgery, although they should understand that without surgery the hemorrhoid
will eventually become fibrosed and resolve over a period of days to weeks.
An elliptic incision can be made over the thrombosis, and the clot and the entire diseased hemorrhoidal plexus can
be removed in one piece. Although the site can be left open, many physicians prefer to place subcutaneous sutures
to limit postoperative pain and bleeding. Suturing in this area, historically, has been avoided because of fear of
complications, yet the rich vascular network in the anal tissues usually provides for rapid healing.
Simple incision over a thrombus after the administration of local anesthesia can be performed to remove the clot,
but this procedure has been associated with a significant rate of rethrombosis. Many experts now recommend
excision of the entire thrombosis and the external hemorrhoidal vessels beneath. This procedure is more extensive
than simple incision but usually yields a better outcome.
Methods and Materials
PATIENT PREPARATION
The patient should be undressed from the waist down and draped. An absorbent pad is placed beneath the patient.
The patient can be seated on the examination table to speak with the physician. At the start of the procedure, the
patient is rolled to the left side in the left lateral decubitus position. The right hip and knee are flexed, and a drape
covers the patient's waist and legs.
EQUIPMENT
Nonsterile Tray for Anoscopy and Anesthesia
Place the following items on a nonsterile drape covering a Mayo stand:
Nonsterile gloves
1 inch of 4 X 4 gauze
4 X 4 gauze soaked with povidone-iodine solution
1 inch of 2 percent lidocaine jelly (Xylocaine) placed on the corner of the drape
Ive's anoscope
Mask (if desired)
10-mL syringe filled with 1 percent lidocaine with a 25-gauge, 1¼-inch needle
Sterile Tray for the Procedure
Place the following items on a sterile drape covering a Mayo stand:
Sterile gloves
2 inches of sterile 4 X 4 gauze
3 hemostats (mosquito clamps)
No. 15 scalpel blade and blade handle
Needle holder
Adson forceps with teeth
Iris scissors (for cutting sutures)
Mayo or tissue-cutting scissors
Allis clamp for holding tissue
4-0 Vicryl suture
Procedure Description
1. The patient is placed in the left lateral decubitus
position. The perianal skin is visualized by having an
assistant separate the buttocks or by taping the buttocks
apart. The anal canal can be visualized using an Ive's
anoscope coated with 2 percent lidocaine jelly. The
extent of the hemorrhoidal disease should be assessed
and coexisting anal pathology excluded before initiating
the procedure. Alternately, anoscopy can be performed
after anesthetic administration (injection) when the
FIGURE 1. The circumferential incision of a
thrombosed hemorrhoids are exquisitely tender.
thrombosed external hemorrhoid opens across
2. The perianal skin and anal canal are cleansed with
the hemorrhoidal plexus, making removal of
povidone-iodine solution. The base of the hemorrhoid is
clots from the vessel easier.
infiltrated with at least 5 mL of 1 percent lidocaine,
using a 25-gauge, 1¼-inch needle. Avoid making
multiple needle sticks in the anal tissues because the
puncture sites can bleed after needle removal. Warn the
patient about impending needle insertion into the tender
tissues.
3. A fusiform (elliptic) excision is made into the anal skin
overlying the thrombosis. It is preferable to make a
radial incision extending out from the anal canal if the
entire hemorrhoid plexus is removed; some physicians
prefer a circumferential incision that exposes more clots
by crossing over more of the hemorrhoidal sinusoids
beneath (Figure 1). Vigorous bleeding may accompany
this incision and can be controlled with direct pressure
FIGURE 2. The fusiform island of skin is
or electrocautery, if needed.
grasped and elevated. Sharp excision of the
4. A clamp can be placed on the fusiform skin island and
clot and hemorrhoidal plexus of vessels in the
traction applied to the skin to reveal the hemorrhoid
subcutaneous tissues is performed.
below (Figure 2). The entire hemorrhoid is sharply
excised with a no. 15 blade or scissors. The entire
hemorrhoidal plexus usually can be removed as one piece attached to the fusiform skin island. Avoid
cutting into the muscle sphincter below the hemorrhoidal vessels.
5. Once the hemorrhoidal plexus and clot have been removed, the base of the wound is examined for residual
small clots. Additional hemorrhoidal tissue or clots can be sharply excised. Some physicians chose to
close the deep wound with subcutaneous, absorbable, buried 4-0 Vicryl sutures to avoid significant
postprocedure bleeding. The sutures should be completely subcutaneous and not penetrate external to the
anal skin. Wound closure can reduce bleeding and discomfort at the surgical site. Alternatively, some
physicians prefer to leave the wound open.
6. The wound should be inspected for adequate hemostasis. If epinephrine is used to anesthetize the wound
and the wound is unsutured, late bleeding (up to several hours postprocedure) can develop once the effect
of the epinephrine wears off. Topical antibiotic ointment is applied to the surgical site, and 1 inch of 4 X 4
gauze is applied over the site between the buttocks. The patient can be given additional gauze for use at
home.
Follow-Up
Most physicians believe that the thrombosed plexus of vessels should not be sent for histologic evaluation,
because analysis of the tissue generally fails to yield useful additional information. If solid tumors or unusual
tissue characteristics are discovered at the time of surgery, histologic analysis of the tissue may be warranted.
The patient should have a follow-up visit at six weeks postprocedure. If extensive coexisting internal hemorrhoids
are noted, these can be managed with infrared coagulation or another destructive modality. Some physicians also
recommend colon examination for all patients with hemorrhoids. The medical literature provides conflicting
recommendations on the need for colon evaluation, but if flexible sigmoidoscopy is performed, it should occur
between six to 12 weeks after the original surgery.
Procedure Pitfalls/Complications
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The Patient Left the Office with the Wound Dry, but
The development of postoperative anal
Returned Later with Extensive Bleeding. Hemorrhoidal
stenosis is rare, but the complication can
plexuses include both arterial and venous vessels. When
be further reduced by avoiding
surgery is performed, the cut arterioles may spasm, and
circumferential incisions on all sides of the
bleeding ceases. If lidocaine with epinephrine is used and
anal canal.
the surgical wound is not closed with suture, the patient can
develop significant bleeding when the effect of the
epinephrine wears off. Some physicians advocate no
epinephrine in the anesthetic and the use of suture to close the wound to limit the risk of late bleeding.
Excessive Scarring or Anal Stenosis Developed After the Surgery. The development of anal stenosis is a
rare, but definite, complication associated with hemorrhoid surgery that can be reduced by avoiding
circumferential procedures on all sides of the anal canal. Performing extensive cautery can limit bleeding
during the procedure but also can induce extensive scarring and should be avoided.
Concern About the Risk of Infection if Wound Is Surgically Closed. Infection after suture closure is an
unusual occurrence, partly because of the rich vascular network in the anal area. Several studies have
confirmed the safety of suture closure, and discomfort and bleeding complications may be reduced by this
technique. Prophylactic antibiotics are prescribed by some physicians for possible postinfection following
suture closure.
Patient Complains That Anoscopy Is Too Uncomfortable Before Hemorrhoid Surgery. Extensive
inspection of the perianal tissues is recommended to exclude coexisting disease. Infectious complications
of the excision procedure may relate to unrecognized infectious processes, such as perianal abscesses.
Persisting pain could relate to a coexisting fissure. The inspection of the anal tissues should not be
deferred, and anoscopy can be performed after administration of the anesthetic to make it more tolerable
for the patient.
Subcuticular Wound Closure Is Very Difficult at the Anus. Suture placement is difficult in the anus
because of the narrow surgical field and because sutures do not hold well in the tissues below the
anoderm. Taking adequate bites of tissue with each pass of the suture needle and placing multiple,
interrupted, buried sutures can ensure proper closure of the wound. The suture should be subcuticular and
not protrude through the anoderm.
The Patient Notices a Tearing Sensation and Bleeding During the First Week After the Procedure.
Passage of hard stool can easily tear the suture line. The need for soft stools must be emphasized to the
patient. Multiple modalities can be used to soften the stools, such as stool softeners, stool-bulking agents
and increased daily consumption of fluids. Even with soft stools, however, it is not unusual for some
tearing to occur at the suture line.
Physician Training
Physicians with proper surgical skills can master this procedure. Extensive training and experience in general and
skin surgery may be needed before attempting this procedure unsupervised. The bleeding that occurs during the
procedure may frighten novice surgeons. The complications of the procedure should be respected, and patients
can be referred to more experienced physicians if a comfort level and adequate experience are lacking; however,
the basic skills needed to perform this procedure are not unlike those for the fusiform excisional biopsy
commonly performed for removal of skin lesions.