172 CHAPTER 5 Infections and inflammatory conditions

Interstitial cystitis

Interstitial cystitis (IC) is a refractory bladder disorder of unknown etiology. Also known as painful bladder syndrome, IC is characterized by daytime and nighttime urinary frequency, urgency, suprapubic and pelvic pain of unknown etiology, and no identifiable pathological cause.

The presence of glomerulations on cystoscopic examination (petechiae seen after bladder wall distention) or Hunner’s ulcers may help confirm clinical suspicion. Only 5% of cases are associated with Hunner’s ulcers (focal regions of panmural inflammation).

The symptom complex is similar to that of prostatitis type IIIB noninflammatory CPPS (prostatodynia).

IC is a diagnosis of exclusion (see Table 5.5). It is diagnosed once other causes for these symptoms have been excluded (e.g., TB, radiation cystitis, bladder tumor, overactive bladder). The presence of uninhibited bladder contractions on urodynamics excludes a diagnosis of IC.

In 1988, the National Institute of Diabetes, Digestive, and Kidney Diseases (NIDDK) described criteria for IC. However, originally developed for research purposes, it identifies patients with more severe disease and some experts do not recommended it for use in clinical practice.

Epidemiology

IC predominantly affects females (~90%). Estimated female prevalence is 18.1 cases per 100,000 from European studies. American data suggest higher rates of 52–67 per 100,000.

Associated disorders

A higher prevalence of allergies, irritable bowel syndrome, fibromyalgia, focal vulvitis, lupus, and Sjögren syndrome has been reported in IC. Anxiety, depression, and adjustment reactions are also found.

Pathogenesis

IC appears to be a multifactorial syndrome. Possible contributing factors include the following:

•Increased mast cells. Studies have demonstrated increased mast cells in bladder smooth muscle (detrusor). Activated mast cells release histamine, which can cause pain, hyperemia, and fibrosis in tissues.

•Defective bladder epithelium. An abnormal glycosaminoglycan (GAG) layer may allow urine to leak past the luminal surface, causing inflammation in muscle layers.

•Neurogenic mechanisms. Abnormal activation of sensory nerves causes release of neuropeptides, resulting in neurogenic inflammation.

•Reflex sympathetic dystrophy of the bladder. Excessive sympathetic activity

•Urinary toxins or allergens

•Bladder autoimmune response

Evaluation

Exclude other causes for symptoms (see Table 5.5). History, examination (including pelvic in women and DRE in men), urinalysis, and culture are

			INTERSTITIAL CYSTITIS		173
	Table 5.5 NIDDK* diagnostic criteria for interstitial cystitis
	Diagnosis criteria	1.	Cystoscopic evidence of Hunner’s ulcer
			or petechiae (glomerulations)
		2.	Bladder/pelvic pain or urinary urgency
	Exclusion criteria	1.	Bladder capacity >350 mL, measured by awake
			cystometry

2.Lack of urgency with a 150mL injection in cystometry

3.Uninhibited contractions during cystometry

4.<9 months from onset

5.Absence of nocturia

6.Symptoms improved by antibiotics, anticholinergics, or antispasmodics

7.Daytime voids <8

8.Bacterial cystitis or prostatitis within 3 months

9.Bladder or ureteral calculi

10.Genital herpes

11.Uterine, cervical, vaginal, or urethral cancer

12.Urethral diverticulum

13.Cyclophosphamideor drug-induced cystitis

14.Tuberculous cystitis

15.Radiation cystitis

16.Bladder tumor

17.Vaginitis

18.<18 years old

* National Institute of Diabetes and Digestive and Kidney Diseases.

mandatory. The IC symptom index questionnaire and voiding diaries are useful. Urodynamics has limited role. Diagnostic studies are as follows.

Cystoscopy

Ten percent of patients will have pink ulceration of bladder mucosa (Hunner’s ulcer). Under anesthesia, the bladder should be distended twice (to 80–100 cmH2O for 1–2 min) and then inspected for diffuse glomerulations (>10 per quadrant in ¾ bladder quadrants).

Bladder biopsy is only indicated to rule out other pathologies such as carcinoma in situ. In conscious patients, bladder filling causes pain and reproduces symptoms.

174 CHAPTER 5 Infections and inflammatory conditions

Intravesical KCl challenge

In 75% of IC patients, installation of 0.4 M KCl into the bladder will provoke pain and symptoms.

Treatment

Patients should understand that there is no known cure, and treatment is for symptom control. The Interstitial Cystitis Association, at www.ichelp. org, is a useful patient resource. Stress reduction, exercise, and diet modification may be helpful.

There are only two FDA-approved medications:

•Pentosan polysulfate sodium: 100 mg PO tid; augments protective GAG layer of bladder to minimize irritative effects

•50% Dimethylsulfoxide (DMSO), weekly intravesical instillation x6 weeks; often used as cocktail with triamcinolone, heparin sodium, NaHCO3

All other medications are off-label.

Oral medications

Tricyclics (amitriptyline) have anticholinergic, antihistamine, and sedative effects. Narcotics are to be avoided.

Nerve stimulation

Transcutaneous electrical nerve stimulation (TENS) or sacral neuromodulation can be used.

Surgery

Transurethral resection, laser coagulation or diathermy of Hunner’s ulcers, and bladder hydrodistention under anesthesia may be beneficial, otherwise surgery should only be considered after failed conservative treatments. Rarely, urinary diversion cystectomy or enterocystoplasty may be required.

Further reading

Moldwin RM, Evans RJ, Stanford EJ, et al. (2007). Rational approaches to the treatment of patients with interstitial cystitis. Urology 69(Suppl 4A):73.

Payne CK, Joyce GF, Wise M, et al. (2007). Interstitial cystitis and painful bladder syndrome. J Urol 177:2042.

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