Smiths General Urology, Seventeenth Edition (LANGE Clinical Medicine)

Authors: Macfarlane, Michael T.

Title: Urology, 4th Edition

Copyright 2006 Lippincott Williams & Wilkins

> Table of Contents > Part Two - Selected Topics > Chapter 33 - Interstitial Cystitis

Chapter 33

Interstitial Cystitis

Interstitial cystitis (IC) is probably the least understood and most controversial of all urologic diseases. Even an agreed-on definition of the syndrome is not accepted; however, it is universally accepted that IC is a diagnosis of exclusion. The most commonly recognized symptoms are urgency, frequency, and suprapubic pain on bladder filling in the absence of any other reasonable causation. Hematuria has been reported in 20% to 30% of cases. It is an uncommon disease, primarily of women aged 30 to 70 years, with a 10:1 female-to-male preponderance. The etiology of IC remains obscure.

Diagnosis

The diagnosis of IC is one of exclusion based entirely on clinical and cystoscopic criteria.

• Chronic history of unexplained bladder irritability and suprapubic pain.

• Frequency and nocturia without incontinence.

• Negative physical examination.

• Negative urinalysis and culture.

• Cystoscopic findings are not mandatory:

  • Characteristic diffuse submucosal pinpoint petechial hemorrhages (glomerulations) on cystoscopy after repeated bladder distention under 80- to 100-cm H₂O pressure (anesthesia required).

  • Ulcerations, once thought to be common, are actually rarely found (Hunner's ulcer occurs in <5%).

• No evidence of carcinoma in situ is found on bladder biopsy and urine cytology; interstitial mast cell infiltration, however, is frequently noted on histology.

• Cystometric studies are essentially normal except for a small bladder capacity.

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Workup

Workup should include urinalysis, urine culture, a careful voiding record, cystoscopy under anesthesia, bladder cytology or biopsy or both, intravenous urogram, and urodynamic studies. Carcinoma in situ and infection must be ruled out. Trial management with antimicrobials, anticholinergics, and antispasmodics is recommended. Relief of symptoms would exclude the diagnosis of IC.

Management

This disease rarely progresses and presents little threat to the patient's health. However, it can cause intolerable morbidity, at times making the patient's life unbearable. The uncertain etiology and diagnosis only worsen matters for these unfortunate patients when they are dealing with physicians. The goal of management is symptomatic relief. Both patient and physician must understand that no sure cure for IC exists. Patient education is important. Therapeutic options include the following:

• Hydraulic distention of the bladder under anesthesia has therapeutic value in approximately 30% of patients, in addition to its diagnostic value.

• Intravesical instillation of dimethyl sulfoxide (DMSO) is the most commonly used treatment for IC and can be expected to give at least temporary relief to 50% to 70% of patients. Fifty milliliters of a 50% solution of DMSO (Rimso-50) is instilled into the bladder by a urethral catheter and allowed to remain for 15 minutes before asking the patient to void. Instillations are repeated every 2 to 4 weeks until relief is obtained.

• Intravesical heparin has antiinflammatory effects and inhibits angiogenesis. Dosage is 10,000 units administered intravesically in sterile water or concomitantly with DMSO.

• The tricyclic antidepressant amitriptyline (Elavil) 12.5 to 150 mg PO daily has been beneficial for patients for whom intravesical therapy has failed.

• Sodium pentosanpolysulfate (Elmiron) is a synthetic sulfated polysaccharide heparin analogue in oral formulation used to repair the glycosaminoglycan (GAG) layer of the bladder. Success with oral Elmiron is unpredictable. Dosage is 100 mg PO tid.

• Transcutaneous electrical nerve stimulation (TENS) is used to relieve pain.

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• Antiinflammatory medications, such as corticosteroids and azathioprine, produce unpredictable results, and the risk of immunosuppressive complications is considered too high for routine use.

• Augmentation cystoplasty with supratrigonal cystectomy or substitution cystoplasty is sometimes necessary as a last resort for patients with intolerable pain or small contracted bladders.

• Dietary restrictions are unsupported by the literature; however, if patients find that their symptoms are exacerbated by specific foods or beverages, then they should be avoided.