How do nerves recover after prostate surgery?

What are the neurovascular bundles and why does prostate surgery damage them?

The neurovascular bundles are two cords of nerves and blood vessels that run along the back and sides of the prostate and carry the signals that start an erection. A 2013 review in Prostate International describes them as "situated posterolaterally and symmetrically to the prostate", in the space between the levator fascia, the prostatic fascia and Denonvilliers' fascia. The nerve fibres come from the inferior hypogastric (pelvic) plexus, and the review says the classical bundle "carries neural impulses to the cavernosal tissue", the spongy erectile tissue of the penis. The same bundles also send branches to the urethral sphincter, which is why bladder control and erections are both at risk.

The bundles sit only millimetres from the prostate capsule. A 2013 review in Reviews in Urology by Hoyland and colleagues says nerve damage is "almost inevitable" because of the proximity of the nerves to the prostate, whether or not the surgeon spares them, and that the damage comes from stretching, cutting or heat during the operation. Surgeons try to lower that damage by dissecting along avascular planes and by using what the Prostate International review calls "athermal, traction-free nerve sparing", meaning no diathermy heat and no pulling on the bundles.

A transurethral resection of the prostate (TURP) for benign enlargement works from inside the urethra and removes the core of the gland, not the capsule, so the bundles are not dissected. The NHS still lists difficulty getting or keeping an erection as a possible complication of TURP.

What is nerve-sparing surgery and who can have it?

Nerve-sparing surgery removes the prostate while leaving one or both neurovascular bundles in place. The US National Cancer Institute (NCI) says that "in some cases, the nerves that control penile erection can be saved with nerve-sparing surgery", but that "this may not be possible in men with large tumors or tumors that are very close to the nerves". Cancer Research UK puts it the same way: the surgeon removes the cancer without removing the nerves, and if the cancer sits close to the nerves, one or both bundles have to go.

Sparing can be bilateral (both sides), unilateral (one side) or none. The choice depends on where the tumour sits, its grade and the surgeon's judgement during the operation. Macmillan Cancer Support lists the factors that shape erection recovery afterwards: age, erection problems before surgery, diabetes, blood pressure medicines, a previous TURP, and how many nerves could be spared. Macmillan adds that recovery is less likely if hormone therapy or radiotherapy follows surgery.

The NCI notes two other physical effects that are relevant to nerve and tissue recovery: a shortening of the penis by 1 to 2 centimetres, for which "the exact reason for this is not known", and a higher chance of inguinal hernia, most likely within the first 2 years.

In India, ask the urologist before surgery whether sparing is planned on both sides, one side or neither, and have that written in the operation note.

How long does nerve recovery take after a prostatectomy?

Nerve recovery is slow: few men recover erections in the first 6 months, and natural recovery can take 18 to 24 months. Dean and Lue, writing in Reviews in Urology in 2005, state that "natural recovery of erections may take as long as 18 to 24 months post RP". Hoyland and colleagues (Reviews in Urology, 2013) go further and say nerves can take "up to 3 years to return to baseline function". Macmillan Cancer Support tells patients that erections may slowly return but that this can take 1 to 2 years.

The reason is the type of injury. Dean and Lue describe neurapraxia, "failure of conduction in a nerve in the absence of structural changes", caused by blunt injury, compression or lack of blood supply, after which function normally returns. A stretched nerve stops conducting but is not severed, so it can recover; a cut nerve regrows only slowly, if at all.

How many men recover depends on how much nerve was spared and on age. A 2009 meta-analysis by Tal and colleagues in the Journal of Sexual Medicine, pooling 22 studies and 9,965 radical prostatectomies, found an overall recovery rate of 58% (95% CI 56 to 60%). Recovery was 60% after bilateral nerve-sparing against 47% after unilateral sparing, 77% in men under 60 against 61% in men 60 and over, and 60% when follow-up ran 18 months or longer against 56% when it was shorter. The 22 studies used 22 different definitions of recovery, so the numbers are a guide, not a promise.

What happens to the penis while the nerves are healing?

While the nerves are silent the penis gets fewer erections, less oxygen-rich blood and, over months, scar tissue. Lin and Wang (Translational Andrology and Urology, 2013) explain that cavernous nerve injury reduces erections, which lowers oxygen levels in the erectile tissue, and that this can progress to cavernosal fibrosis and a venous leak, where blood drains out of the penis too fast to hold an erection.

Hoyland and colleagues report the downstream numbers: after radical prostatectomy 59% of patients have arterial insufficiency, and a further 26% have venous leakage on top of it. Smooth muscle in the penis atrophies 4 to 8 months after surgery, which is why these authors argue for early oxygenation of the tissue.

Penile shortening is part of the same process. Lin and Wang cite shortening in 68 to 71% of men after radical prostatectomy, and the NCI gives the typical loss as 1 to 2 centimetres. In the study by Raina and colleagues that Lin and Wang summarise, 23% of men who used a vacuum device daily reported shrinkage against 85% of men who did not.

These tissue changes are the rationale for penile rehabilitation. Cancer Research UK defines it as treatment that aims to maintain blood flow to the penis, reduce damage to penile tissue and encourage erections, and advises starting "before or soon after" prostate cancer treatment whether or not the man is sexually active. The goal is to keep the tissue healthy so that, when the nerves do conduct again, the penis can still respond.

Does penile rehabilitation with PDE5 inhibitor tablets work?

Tablets help erections on the day they are taken, but the best evidence says a daily schedule does not speed nerve recovery. A 2018 Cochrane review (Philippou and colleagues) included 8 randomised trials with 1,699 men. Scheduled PDE5 inhibitors (sildenafil, tadalafil, vardenafil) compared with placebo or no treatment "may have little or no effect" on self-reported potency up to 12 months (risk ratio 1.13, 95% CI 0.91 to 1.41), and the evidence was very low quality. Daily use compared with on-demand use showed no difference in potency in the short term (RR 0.97) or long term (RR 1.00). The authors conclude that scheduled use "may not promote self-reported potency and erectile function any more than on demand use", and that further research is likely to change the findings.

That verdict overturns an older, smaller literature. Dean and Lue summarise an industry-sponsored trial (Padma-Nathan and colleagues) in which 27% of men on nightly sildenafil recovered "normal" spontaneous erections against 4% on placebo; it was small, and the Cochrane pooled analysis did not confirm the effect.

Two practical points stand. Dean and Lue note that the response to sildenafil is poor in the first 9 months after surgery and improves up to 2 years, because a tablet needs some nerve signal to work. Hoyland and colleagues report response rates of 15 to 80% after radical prostatectomy, poor in men with venous leak or fibrosis, and theoretically nil after non-nerve-sparing surgery.

The sensible reading: tablets treat erections on demand, prescribed by a urologist, and are not a proven cure for the nerve injury.

Do vacuum devices help nerve and tissue recovery?

Vacuum erection devices do not repair nerves, but the trial evidence says early use protects the erectile tissue and penile length while the nerves heal. A 2018 systematic review and meta-analysis by Qin and colleagues in the American Journal of Men's Health pooled 6 randomised trials with 273 men after prostatectomy. Early vacuum therapy raised the IIEF-5 erection score by a mean 4.76 points (95% CI 3.28 to 6.24) and made reversal of penile shrinkage five times more likely (odds ratio 5.44). When a device was added to a PDE5 inhibitor, men gained a mean 1.26 cm of length compared with tablets alone. No serious adverse events were reported; mild ones were penile discomfort (9.9% in one trial), bluish discolouration (3.6%), headache and numbness.

The authors are blunt about the weaknesses: the trials were small, none was double-blind or placebo-controlled, and the quality was low to moderate. Lin and Wang say "well designed clinical studies with long-term follow up are not available at this time". Their explanation of the mechanism is that negative pressure pulls arterial blood into the penis, which in rat studies reduced hypoxia and fibrosis.

Published protocols are simple: Lin and Wang describe daily use from the day after catheter removal for 90 days, or 10 minutes a day without the constriction ring. Dean and Lue recommend the device as a first-line option early on because it "does not require intact neural tissue". Hoyland and colleagues note compliance of up to 80%, against 40% for penile injections.

What helps nerve recovery and what is unproven?

What helps is a nerve-sparing operation, early protection of the penile tissue, and time; nothing yet makes the nerves themselves regrow faster.

The vitamins, supplements and herbal products marketed in India for nerve repair appear in none of the sources above. Cancer Research UK adds that staying active, a healthy weight, stopping smoking and less alcohol may improve erections, and that some studies suggest pelvic floor exercises help.

Ask your oncologist and urologist to agree one rehabilitation plan before discharge. If erections have not begun to return by 12 months, or you develop pain, curvature or a lump in the penis, ask for an andrology review. This guide is general information from the sources listed below, not medical advice; a registered doctor makes decisions with you.