Nerve-sparing prostatectomy: preserving erectile function

Robotic nerve-sparing radical prostatectomy is now the standard for patients with localised prostate cancer and good preoperative erectile function. Preservation of the neurovascular bundles — anatomical structures a few millimetres wide running posterolaterally to the prostate — largely determines erectile function recovery in the medium and long term.

Anatomy of the neurovascular bundles

The neurovascular bundles (NVB) carry the S2–S4 parasympathetic fibres innervating the corpora cavernosa. They run in the plane between the lateral prostatic fascia and Denonvilliers' fascia, with significant individual variability in anterolateral distribution. Intrafascial preservation (within the prostatic fascia) offers maximum nerve sparing but requires intraoperatively confirmed negative surgical margins.

Degrees of nerve-sparing

• Bilateral intrafascial: maximum preservation, indicated only in T1c–T2a low-risk disease with favourable preoperative MRI
• Bilateral interfascial: standard for most eligible patients; optimal balance between oncological control and functional recovery
• Unilateral interfascial: when neuroimaging or biopsy indicates unilateral capsular extension
• Non nerve-sparing: T3 disease, Gleason ≥ 8 with NVB involvement on imaging, or PSA > 20 without favourable score

Selection criteria

The ideal candidate presents: age < 65, preoperative IIEF-5 ≥ 17, cT ≤ 2b, Gleason ≤ 7 (3+4), PSA < 10 ng/mL, no perineural invasion on systematic biopsy. Multiparametric MRI (mpMRI) 3T is mandatory to assess extracapsular extension before the technical decision.