Intravesical prostatic protrusion (IPP) is increasingly recognized as a clinically relevant anatomical factor in benign prostatic hyperplasia (BPH), with potential implications for bladder outlet obstruction severity and surgical outcomes. This study aimed to evaluate the relationship between IPP severity and postoperative functional outcomes and complications in patients undergoing transurethral enucleation of the prostate (TUEP).

We retrospectively reviewed 139 patients who underwent TUEP for BPH between January and December 2019. Among them, 79 patients with complete preoperative and postoperative uroflowmetry data were included for functional outcome analysis. Patients were stratified into two groups based on IPP: <10 mm and ≥10 mm. Uroflowmetry parameters—including voided volume, peak urinary flow rate (Qmax), and post-void residual volume (PVR)—were assessed preoperatively and at three months postoperatively. To evaluate postoperative complications, particularly urethral stricture, 111 patients with complete IPP data were enrolled and further categorized into three IPP grades: Grade 1 (<5 mm), Grade 2 (5–10 mm), and Grade 3 (>10 mm).

Among the 79 patients analyzed for functional outcomes, those with IPP ≥10 mm had significantly lower preoperative Qmax (4.78 ± 1.72 vs. 9.93 ± 5.17 mL/s, p = 0.001) and voided volume (108.3 ± 75.7 vs. 211.2 ± 126.1 mL, p = 0.011), but demonstrated greater postoperative improvements in Qmax (14.78 ± 6.04 vs. 8.69 ± 10.38 mL/s, p = 0.028) and voided volume (155.3 ± 57.1 vs. 64.1 ± 130.5 mL, p = 0.005). No significant differences were observed in PVR, PSA, or comorbidities between the two groups. Among the 111 patients analyzed for postoperative complications, urethral stricture occurred more frequently in the moderate IPP group (Grade 2: 10/47, 21.3%) compared to Grade 1 (3/45, 6.7%) and Grade 3 (0/19, 0%) (p = 0.020). Similarly, optical internal urethrotomy was significantly more common in the Grade 2 group (p = 0.006), suggesting a non-linear relationship between IPP and stricture risk.

IPP is a valuable preoperative anatomical indicator that predicts both functional improvement and complication risk following TUEP. Larger IPP (≥10 mm) is associated with greater postoperative improvement in urinary flow and voided volume, while moderate IPP (5–10 mm) carries the highest risk of urethral stricture. Preoperative IPP assessment may support individualized surgical planning and risk stratification in BPH management.