Do cystometric findings predict the results of intravesical hyaluronic acid in women with interstitial cystitis?

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 greater than or equal to 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 (Cmax) 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 greater than or equal to 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 (greater than or equal to30%) 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 Cma, of < 350 cc (Group I), while 16 patients had a C-max of greater than or equal to 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 Cma, reduction of greater than or equal to 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 greater than or equal to 350 cc, may have increased potassium sensitivity as a sign of IC and show symptom improvement after hyaluronic acid instillation therapy. (C) 2004 ElsevieB.Vr B.V. All rights reserved.