Study design, materials and methods
A total of 64 men who had undergone unilateral or bilateral robot-assisted nerve-sparing RARP more than 3 months earlier were enrolled in the study. All patients had a prostate-specific antigen (PSA) level below 0.2 ng/mL at 3 months after surgery. In Group 1 (n=32), the mean age was 59.3±7.1 years (range, 42-72), and the mean duration of ED was 7.0±4.5 months (range, 3-19). In Group 2 (n=32), the mean age was 57.6±5.6 years (range, 48-68), and the mean duration of ED was 7.8±3.9 months (range, 3-17). Patients in Group 1 underwent two treatment sessions per week for 6 weeks. The first weekly session included ESWT applied to the penis, followed by APGF injections into the corpora cavernosa and subsequent APGF activation using ESWT. The second weekly session consisted of penile ESWT alone. Each ESWT session comprised 5,000 impulses. Patients in Group 2 received tadalafil 5 mg once daily. Assessments were performed at baseline and on day 60 using the following instruments: the International Index of Erectile Function-5 (IIEF-5), Erection Hardness Score (EHS), Sexual Encounter Profile (SEP), Global Assessment Question (GAQ), penile duplex Doppler ultrasonography (PDDU), International Prostate Symptom Score (IPSS), International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF), quality-of-life (QoL) score, and uroflowmetry parameters (Qavg and Qmax). Inclusion criteria were the absence of distant or nodal metastases, post-RARP IIEF-5 <21, peak systolic velocity (PSV) <30 cm/s and/or resistive index (RI) <0.8 on PDDU, and preserved erectile function before surgery. The study was approved by the Ethics Committee of the Medical Institute of RUDN University.
Results
No adverse events were observed in Group 1. By day 60, Group 1 demonstrated significant improvement in erectile function and urinary parameters. Median IIEF-5 increased from 10 (5-13.5) to 18.5 (14.5-23) (p<0.05), SEP from 2 (1-3) to 3 (2-4.2) (p<0.05), and EHS from 1 (1-2) to 3 (2-3.5) (p<0.05). IPSS decreased from 6 (3-11) to 3.5 (0.75-7.0) (p<0.05), while QoL remained unchanged (p=0.7). ICIQ-SF decreased from 4 (1.7-6.2) to 1.5 (0-4) (p<0.05). According to PDDU, PSV increased from 22.7 cm/s (16.1-26.5) to 29.2 cm/s (23.7-35.9) (p<0.05), and RI increased from 0.85±0.1 (0.8-0.9) to 0.89±0.09 (0.86-0.93) (p<0.05). Based on GAQ responses, 19 patients (73%) reported a positive treatment effect. Post-treatment intergroup analysis revealed significant differences in IIEF-5, SEP, EHS, ICIQ-SF, PSV, and RI in favor of Group 1, whereas no significant between-group differences were found for IPSS or QoL. Uroflowmetry parameters (Qavg and Qmax) improved significantly by day 60; however, no significant intergroup differences were observed.
Interpretation of results
The combination of APGF and ESWT appears to be a safe and effective treatment option for ED after robot-assisted nerve-sparing radical prostatectomy. Compared with daily tadalafil therapy, this approach was associated with greater improvement in erectile function, as confirmed by validated questionnaires and penile duplex Doppler ultrasonography.