Bladder hydrodistension is commonly used to diagnose and treat patients with interstitial cystitis/bladder pain syndrome (IC/BPS). The procedure has been shown to have minimal morbidity and provide symptomatic relief in a large number of patients with IC/BPS. However, the bleeding is almost inevitable after hydrodistension with a pressure of 60-100 cmH2O. Therefore, bleeding complications such as bladder clots and urinary retention should be concerned and handled properly. Perioperative management of antithrombotic therapy requires assessment of patient risk for thromboembolism and weighing it against risk for perioperative bleeding complications. Considering that the risk of overall complications in IC/BPS patients on antithrombotic therapy after hydrodistension is unclear, we performed the first study to investigate this topic.

We retrospectively reviewed patients with IC/BPS who underwent hydrodistension during January 2010 and May 2021. Patients with and without antithrombotic drugs were identified and grouped and their medical records were reviewed. Perioperative data and symptom scores were assessed. The rates of complications in the two groups were recoded 3 months and at last visit postoperatively.

Table 1 Inclusion and exclusion criteria of patients with IC/BPS
Inclusion criteria	
  1) Over 18 years old when signing an informed consent;
  2) Previously diagnosed with IC/BPS for a duration of > 6 months;
  3) O’Leary-Sant Interstitial Cystitis Symptom and Problem Index scores over 18;
  4) Undergoing hydrodistension during the hospitalization;
  5) Patients with adequate medical records.
Exclusion criteria	
1. General conditions	
  1) Currently diagnosed with cancer, or have previous history of cancer within the preceding 5 years;
  2) Currently diagnosed with severe heart, lung, liver, kidney, or blood disorders;
  3) Pregnant women;
  4) During the follow-ups, patients underwent other surgeries that impacted the judgment of complications of hydrodistension.
2. Urological symptoms	
  1) Have previous history of urinary infection (e.g., bacterial cystitis, bladder tuberculosis, urethritis, genital chlamydia infection, and genital herpes) within 12 weeks;
  2) Currently diagnosed with any of following diseases, which had similar symptoms with IC/BPS.
       a. Bladder diseases (carcinoma, overactive bladder, neurogenic bladder, bladder stone, radiation cystitis)
       b. Urethral diseases (urethral diverticulum, urethral stricture, urethral stone)
       c. Gynaecological diseases (endometriosis, uterine fibroids, vaginitis, menopausal syndrome, pelvic organ prolapse)
       d. Others (neurogenic urinary frequency, polyuria)
  3) Have previous history of augmentation cystoplasty or cystectomy;
  4) Have previous history of chemical compound (such as cyclophosphamide) derived cystitis.
3. Treatment related	
  1) History of the following therapies within 12 weeks: hydrodistension, intravesical laser therapy, intravesical electrical coagulation, transurethral resection, pelvic reconstructive surgery, nerve stimulation for pain relief;
  2) Received intravesical instillation of any drugs within 12 weeks.

A total of 387 patients were eventually included. Among them, 29 (7.5%) patients were on systemic antithrombotic therapy and 358 (92.5%) were not. Compared with non-antithrombotic group, patients on antithrombotic therapy presented a longer hospital stay (P=0.033) and a longer catheterization time (P=0.034). Moreover, the patients with antithrombotic drugs had increased odds of bladder tamponade (OR=6.76, P=0.019) and urinary retention (OR=5.79, P=0.033) both 3 months postoperatively and last follow-up. No thromboembolic events were identified during the study period.

1. Patients with interstitial cystitis/bladder pain syndrome (IC/BPS) on antithrombotic therapy had increased odds of bladder tamponade and urinary retention after hydrodistension.

2. A comprehensive management scheme to balance bleeding complications and antithrombotic agents is needed for individuals.

3. Suggestions to balance the antithrombotic use and bleeding complications were provided.

Longer hospital stays, longer catheterization time, and increased odds of bladder tamponade and urinary retention were observed in patients with IC/BPS on antithrombotic therapy after hydrodistension. A comprehensive management scheme to balance bleeding complications and antithrombotic agents is needed for individuals.