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Cystectomy for patients with Hunner‐type interstitial cystitis at a tertiary referral center in Japan

To evaluate the outcomes of partial and total cystectomy in patients with refractory Hunner‐type interstitial cystitis (HIC).


| INTRODUCTION
Hunner-type interstitial cystitis (HIC) is a chronic inflammatory disease of the urinary bladder of unknown etiology, clinically characterized by persistent pelvic pain and lower urinary tract symptoms such as urinary frequency and urgency. 1 The progressive nature of this disease in some patients can result in severe bladder contraction, leading to a major increase in urinary frequency and/or urinary leakage. Associated vesicoureteral reflux (VUR) may cause hydronephrosis, recurring pyelonephritis, or irreversible renal dysfunction. Cystectomy may be the ultimate treatment for patients with end-stage HIC, as described in clinical guidelines for patients with interstitial cystitis/bladder pain syndrome (IC/BPS). [1][2][3] Because this procedure is rarely performed, however, pertinent information on cystectomy, such as candidate selection, surgical procedures, possible complications, and treatment prognosis, is limited.
The present study describes our 20-year experience with 17 patients who underwent cystectomy for end-stage HIC.

| Ethics statement
The institutional review board of the University of Tokyo approved the study protocol, including the use of an opt-out methodology to obtain informed consent (approval no. 3124). Participants were informed about the study using generally accessible contact information. Written informed consent was provided by participants who chose to take part in this study. All procedures followed appropriate guidelines.

| Patients
The clinical database of the University of Tokyo Hospital was retrospectively reviewed to identify patients with end-stage HIC who underwent supratrigonal partial cystectomy with augmentation

| Surgical procedures
Cystectomy was considered for end-stage HIC patients with a con-

| Assessment and evaluation
Symptoms were assessed using an 11-point numerical rating of pain

| DISCUSSION
The present study reports outcomes in 17 consecutive patients who underwent cystectomy for end-stage HIC at a tertiary referral center for IC/BPS in Japan. Although TC-IC was a more invasive procedure and more likely to cause postoperative complications than PC-CP, TC-IC was able to achieve almost complete pain relief and a higher rate of patient satisfaction.
Endoscopic electrocautery of Hunner lesions with bladder hydrodistension is regarded as the most promising treatment for HIC. 6,7 However, intractable bladder pain and associated lower urinary tract symptoms may persist even after repeated sessions of electrocautery.
Some patients progressively develop contracted bladder, which frequently induces VUR and/or hydronephrosis. 8 Cystectomy may be an option for these patients with end-stage HIC. [1][2][3] To date, however, optimal patient selection and standardized surgical procedures have not been established.
Our center regards patients with a contracted bladder and markedly impaired QOL resulting from intractable bladder pain or extremely severe bladder storage symptoms, or upper urinary tract events such as VUR, persistent hydronephrosis, and recurrent pyelonephritis that affects renal function, as candidates for cystectomy.
The number one priority of our patients was complete symptom relief; therefore, they tended to select TC as the surgical approach of choice since several studies suggest that TC is likely to provide greater symptom relief than PC. [9][10][11][12] For example, complete pain resolution was achieved by 9 (90%) of 10 women after TC, 11 with a patient satisfaction rate >77% despite the high complication rate (60%). By contrast, persistent bladder pain was experienced by 8 (33%) of 24 patients 9 and by 6 (75%) of 8 patients 10 after PC. Furthermore, persistent/ recurrent pain was reported in 5 (17%) of 29 patients who underwent PC-CP, compared with none (0%) of 6 patients who underwent TC-IC. 12 Meanwhile, other studies found that PC-CP has modest success rates in patients with refractory IC/BPS. 13 The strength of this study is that it is the first case-series report of cystectomy for HIC patients in Japan; therefore, the data increase the knowledge base regarding this relatively uncommon surgical procedure.
In conclusion, the present study demonstrated that TC-IC provided highly reliable pain relief and satisfaction in patients with endstage HIC; however, the small case number and limited methodology mean that the results should be interpreted with caution. Further studies are needed to identify appropriate candidates and optimal surgical procedures for refractory IC/BPS.