Minimally invasive surgical therapies (MIST), including water vapor thermal therapy (WVTT) and prostatic urethral lift (PUL), are increasingly adopted for benign prostatic hyperplasia (BPH), particularly in elderly patients with multiple comorbidities. While these procedures are considered safe, the relative contributions of patient-related versus procedural factors to perioperative bleeding risk remain unclear.
We hypothesized that continuation of antithrombotic therapy, rather than procedural characteristics, is the principal determinant of bleeding complications following MIST. This study aimed to evaluate perioperative safety and identify independent predictors of bleeding complications.

We conducted a multicenter retrospective cohort study including 377 patients undergoing MIST for BPH across 12 institutions (WVTT: n=280; PUL: n=97).
Perioperative complications were graded according to the Clavien–Dindo classification. Bleeding-related complications were predefined as gross hematuria, requirement for bladder irrigation, transurethral coagulation, or pelvic hematoma.
Multivariable logistic regression analysis was performed to identify independent predictors of bleeding complications. Covariates included age, body mass index, prostate volume, intravesical prostatic protrusion, prostate-specific antigen, comorbidities, surgical procedure, operative time, surgeon experience, and continuation of antiplatelet or anticoagulant therapy.

Overall complication rates were low and comparable between WVTT and PUL (12.1% vs 10.3%, p=0.64), with no Clavien–Dindo Grade ≥IV complications observed (Table 1). The incidence of individual complications, including urinary tract infection, gross hematuria, and transient urinary retention, did not differ significantly between procedures.
On multivariable analysis, continuation of antithrombotic therapy emerged as the only independent predictor of bleeding complications (Figure 1):
・Antiplatelet therapy: OR 1.89 (95% CI 1.02–3.76), p=0.041
・Anticoagulant therapy: OR 2.34 (95% CI 1.11–4.96), p=0.025
In contrast, procedural factors (WVTT vs PUL), operative time, and surgeon experience were not associated with bleeding risk.

This study demonstrates that perioperative bleeding risk following MIST is primarily determined by patient-related factors rather than procedural characteristics.
Despite inherent differences between WVTT and PUL, both procedures showed similarly low complication rates, reinforcing the overall safety of MIST. However, continuation of antithrombotic therapy significantly increased bleeding risk, independent of surgical modality or operator-related factors.
These findings challenge the conventional emphasis on procedural selection as a determinant of perioperative risk. Instead, they suggest that patient anticoagulation status is the dominant driver of bleeding complications in this setting. Therefore, optimizing perioperative antithrombotic management may have a greater impact on outcomes than selecting between MIST techniques.

Perioperative outcomes after MIST for BPH are comparable across procedures and characterized by a low incidence of complications. However, continuation of antithrombotic therapy significantly increases bleeding risk, independent of surgical technique.
Bleeding risk in MIST is driven more by patient anticoagulation status than by procedural choice, highlighting the importance of individualized perioperative management strategies.