European Urology

Abstract

Introduction and objectives:

According to National Institute of Health (NIH) criteria, a bladder capacity of less than 350 cc is an automatic exclusion for a diagnosis of Interstitial Cystitis (IC). In the present study, patients, showing symptoms of IC and with bladder capacities of <350 and ≥350 cc were tested as to their response to a intravesical hyaluronic acid therapy.

Methods:

The study included 48 patients with clinical symptoms of IC and a positive 0.4 M potassium sensitivity test. Maximum bladder capacity (C_max) was assessed for the 0.9% NaCl solution first and then for the 0.2 M KCl solution. After the NaCl cystometry, patients were separated into two groups: Group I with a C_max of <350 cc and Group II with a C_max of ≥350 cc. Both groups were again separated in two further groups as to the respective percentage reduction of C_max with the 0.2 M KCl solution: Group Ia/IIa (≥30%) and Group Ib/IIb (<30%). Patients were treated with weekly instillations of 40 mg hyaluronic acid for 10 consecutive weeks. Pre- and post-treatment bladder symptoms were evaluated through their visual analog scale (VAS) scores.

Results:

With the saline solution, 32 patients had a C_max of <350 cc (Group I), while 16 patients had a C_max of ≥ 350 cc (Group II). Evaluation of VAS scores confirmed a positive response, i.e. symptom relief, to hyaluronic acid therapy, irrespective of bladder capacity. The improvement was particularly evident in patients with a C_max reduction of ≥30% versus those with a reduction of <30% with the 0.2 M KCl solution (p = 0.003).

Conclusion:

The present study demonstrates that patients with typical IC symptoms and a cystometric bladder capacity of ≥350 cc, may have increased potassium sensitivity as a sign of IC and show symptom improvement after hyaluronic acid instillation therapy.