SSAT - Patient care guidelines - Treatment of Perineal Suppurative Processes

SSAT Patient Care Guidelines

Treatment of Perineal Suppurative Processes

Introduction
Suppurative processes in the perineum and surrounding areas can be a frightening, if not dangerous situation for patients and a challenge for their physicians. Abscesses, fistulas and chronic inflammatory conditions such as pilonidal cysts, hidradenitis suppurativa and pruritis ani are the most common of these maladies and will be addressed in these guidelines.

Clinical Presentation
Most anorectal infections originate in the crypto glandular area located in the anal canal at the level of the dentate line. Abscesses within these glands can then penetrate the surrounding sphincter and track in a variety of directions. This leads to larger abscesses within the perianal, intersphincteric, ischiorectal, and supralevator spaces. A small number of anorectal abscesses have a non-crypto glandular etiology such as Crohn's disease, atypical infection (e.g., tuberculosis, lymphogranuloma venereum), malignancy, or trauma. Particularly virulent organisms, immunologic deficiency in the patient (e.g., poorly controlled diabetes, HIV), or localized scarring from previous operations can make the diagnosis more challenging. Fever, rigors, and shock may occur before more subtle localized findings. Pain and swelling are the most frequent complaints. Bleeding, purulent discharge and fevers may also be present. A perianal abscess is usually evident at the anal verge. An inflammatory process in the soft tissues of the buttock would more commonly indicate a perirectal abscess. Pelvic pain and dysuria may herald a supralevator abscess. The majority of patients with a fistula-in-ano have a history of abscess development with persistent drainage, pain and possibly bleeding. The external opening on the skin is evident and digital rectal exam, anoscopy or proctoscopy may reveal an indurated area in the anal canal corresponding to the internal opening. Fistulae are categorized according to their relationship with the external sphincter complex. The majority of these fistulae are intersphincteric and about one fourth are transphincteric. If there is any suspicion of an underlying disease such as Crohn’s or immune suppression, this should be thoroughly evaluated prior to the formal treatment of the fistula. Pilonidal cysts initially present as an abscess and/or cellulitis in the sacrococcygeal area. Spontaneous drainage often occurs followed by chronic drainage from the secondary sinuses. Some of these may track toward the anus, potentially being confused with a fistula-in-ano or hidradenitis suppurativa. The latter is a chronic suppurative disease of the epidermal apocrine sweat glands. Consequently, it can occur in the perineal/perianal region, in the areolar area of the breasts and quite frequently in the axillae. It is most commonly seen in the second thru fourth decades of life and is thought to be hormonally influenced.

In primary pruritis ani, impaired sphincter function predisposes this area to moisture and inflammatory fecal elements from such dietary elements as caffeinated and acidic dietary products. Excessive cleansing or poor hygiene will also initiate an irritative process. Intertrigo, a mixed bacterial infection associated with obesity, may also be involved. Pinworms should be considered in children and exposed adults. Pruritis vulvae, resulting from urinary incontinence or vaginal discharge may spread to the perianal region, and mycotic infections should also be considered in the differential diagnosis.

Treatment
Anorectal pain that prevents a digital examination necessitates an examination under anesthesia. Needle aspiration can demonstrate a collection of pus that is accessible to percutaneous drainage. As with any abscess, incision and drainage is the definitive form of therapy. Antibiotics should also be considered when there is significant cellulitis surrounding the abscess or when the patient is immunocompromised or has cardiac valvular pathology. Perianal and ischiorectal abscesses can usually be drained using local anesthesia if they have tracked to the subcutaneous area. A cruciate incision or an elliptical excision of skin overlying the area of fluctuance is recommended to avoid premature closure of the drainage site during the period of resolution. The surgical incision should be as close to the anal verge as possible, so as to minimize the length of a potential fistulous tract. If the abscess cavity is large, and the procedure is being performed under general anesthesia, digital exploration should be performed to break up any loculations. Packing of the wound is only necessary for initial hemostasis. Adequate drainage, followed by frequent sitz/tub baths, especially after bowel movements, will reduce the risk of continued infection and recurrence. If there is palpable crepitus, a Gram stain of the tissue/fluid can be helpful in identifying clostridia.

Established operative goals for an anal fistula are to open the tract and remove the epithelial lining by curettage, electrocautery, etc. There has been some success in the use of fibrin glue for these fistulas. Several methods of determining the configuration of a fistulous tract are possible. Any resistance to the passage of a probe should be avoided so as to prevent the creation of false passages. If the internal opening is not evident, injection of dilute methylene blue dye, milk or hydrogen peroxide into the external opening with an angiocatheter may facilitate the visualization. Judicious unroofing of the observable tract may also allow better recognition of the entire tract. Pre operative trans-anal ultrasound and fistulography are useful diagnostic modalities to be considered. If little or no external sphincter muscle is involved, the external opening and skin overlying the tract may be excised. When greater than half of the external sphincter muscle is involved, or in the patient where sphincter integrity is already at risk, a seton can be applied. In this setting, after the skin and involved internal sphincter are opened, a strip of material is inserted around the overlying external sphincter component and tied snugly. Setons can be fashioned from silk sutures, vessel loops or Penrose drains. During the 1-2 months following the operation, the seton will erode into the muscle and cause an inflammatory response, which prevents significant retraction of the sphincter ends. Either the seton will completely erode through, or the remaining smaller amount of external sphincter can then be transected. A newer alternative, after the seton stabilization period, is the instillation of fibrin glue into the tract after the internal opening is closed with a suture. Treatment in the acute phase of a pilonidal cyst/abscess involves simple incision and drainage. Antibiotics are used if there is significant cellulitis. Any septations should also be disrupted. Because hair and particulate matter are often found within the cavity/sinuses, the use of depilatory cream should be considered to lower the risk of recurrence. The development of chronic sinuses will require further operative intervention for removal.

For hidradenitis suppurativa, unless there are abscesses that need operative drainage, local symptomatic therapy and antibiotics for the cellulitis is initially adequate. Unfortunately, chronicity is common and the drainage and pain can be debilitating. Because the etiology involves the epidermal sweat glands, the only definitive treatment is the excision of involved tissue. Wound healing by secondary intention is frequently chosen, but very large areas may need coverage with surrounding tissue transfers. In order to optimize the healing of complicated wound closures, a temporary diverting colostomy should be considered.

With pruritis ani, patient education, reassurance and close follow-up are imperative. The goal is to attain clean, dry, intact skin. Overzealous cleansing, scratching and colored or perfumed toilet papers should be avoided. Secondary pruritis ani can result from anatomical pathology of the anorectum such as fistulae, fissures and hemorrhoids. Infectious processes, radiation damage and neoplasms can also be responsible.

Risks
The potential effect on continence is an important consideration in the treatment of any anorectal suppurative condition. Incision and drainage should be completed with as little involvement of the sphincter musculatures as possible. The risks of fecal incontinence and possible recurrence of the suppurative process should be discussed with the patient before any operative intervention on the anorectum.

Because of the significant risk for chronic morbidity following an anal fistulotomy in patients with Crohn’s Disease, observation alone should always be considered with asymptomatic fistulae. An interventional alternative is placement of a seton to control the tract(s) and prevent abscess formation. When treating chronic hidradenits, as with any non-healing lesion, a malignant process should be ruled out by biopsy.

Topical steroids compromise normal skin resistance to trauma and infection. While topical anesthetic agents provide temporary comfort, they are often sensitizing and can worsen irritation and inflammation. Pruritis ani is usually symmetrical around the anus. Persistent, unilateral lesions should always be biopsied to rule-out a malignant process.

Qualifications for Performing Surgery on Perineal Suppurative Processes
The qualifications of a surgeon to perform any operative procedure should be based on education, training, experience and outcomes. At a minimum, the surgical treatment of perineal suppurative processes should be carried out by surgeons who are certified or eligible for certification by the American Board of Surgery, the American Board of Colorectal Surgery, the Royal College of Physicians and Surgeons of Canada, or their equivalent.

Suggested Readings
Vasilevsky, C-A. Fistula-in-Ano and Abscess. 1998. In Fundamentals of Anorectal Surgery, 2nd edition.
Beck D and Wexner S, eds. Saunders, pub. Pp. 153-173.

Karulf R and Perry WB. Pilonidal Disease. 1998. In Fundamentals of Anorectal Surgery, 2nd edition.
Beck D and Wexner S, eds. Saunders, pub. Pp. 225-232.

Waters GS, Nelson H. Perianal Hidradenitis Suppurativa. 1998. In Fundamentals of Anorectal Surgery, 2nd edition.
Beck D and Wexner S, eds. Saunders, pub. Pp. 233-236.

Church JM, Fazio VW, Lavery IC, et al. The differential diagnosis and co morbidity of hidradenitis
suppurativa and Crohn's disease. 1993. Intl J Colorectal Dis; 8: 117-119.

Corman M. Anorectal abscess and Anal fistula. 1998. In Colon and Rectal Surgery, 4th edition. Lippincott-Raven, pub. Pp 224-271.

Gordon PH. Anorectal abscesses and fistula-in-ano. 1999. In Principles and Practice of Surgery for the
Colon, Rectum and Anus, 2nd edition. Gordon PH, Nivatvongs S, ed. Quality Medical Publishing, pub. Pp 241-286.

Nivatvongs S. Pilonidal Disease. 1999. In Principles and Practice of Surgery for the Colon, Rectum and
Anus, 2nd edition. Gordon PH, Nivatvongs S, ed. Quality Medical Publishing, pub. Pp 287-301

Smith LE. Perianal dermatologic disease. In Gordon PH, Nivatvongs S: Principles and Practice of Surgery
for the Colon, Rectum and Anus. St. Louis, Quality Medical Publishing, Inc., 1992:281-300.

Friend WG. Pruritus Ani. In Fazio V (ed): Current Therapy in Colon and Rectal Surgery. Toronto, BC Decker Inc., 1990:42-45.

Key Words - Perianal abscess, perirectal abscess, fistula-in-ano, Crohn’s disease, anorectal abscess, hidradenitis suppurativa

Board Approved February 21, 2004

These patient care guidelines were written for the primary care physicians on a variety of digestive diseases to assist on when to refer the patient for surgical consultation.
Their goal is to guide PRIMARY CARE physicians to the appropriate utilization of surgical procedures on the alimentary tract or related organs and they are based on critical review of the literature and expert opinion. Both of the latter sources of information result in a consensus that is recorded in the form of these Guidelines. The consensus addressses the range of acceptable clinical practice and should not be construed as a standard of care. These Guidelines require periodic revision to ensure that clinicians utilize procedures appropriately but the reader must realize that clinical judgment may justify a course of action outside of the recommendations contained herein.