The approach involves a 10-15 cm incision in the abdomen, which allows optimal access to the operative field, but inevitably causes post-operative pain typically associated with such incisions. In my own series using the open retro pubic approach, the side effects at the time of operation are now very infrequent (less than 2% major complications) and the positive margin rate is now less than 10% and the urinary incontinence rate measured at one year after surgery is now 1.5%. In the young, potent patient, 50% of patients achieve normal sexual function after two years of follow-up with bi-lateral nerve sparing procedures, whilst 80 to 90% achieve reasonable sexual function with our without Viagra after the same period.
Nerve sparing radical prostatectomy
Patrick Walsh, Professor of Urology at John Hopkins Medical Institution performed the first nerve sparing radical prostatectomy in April 1982. Today, in experienced hands, it is possible to preserve both neurovascular bundles (the nerve supply to the penis) in most men who are candidates for prostate cancer surgery. With improved surgical techniques and the availability of Viagra like tablets, most potent healthy men less than 65 years of age should be potent following surgery. If nerve sparing is performed correctly, it is possible to completely remove the cancer and protect the erection nerves. Nerve sparing can be performed by the open technique or by laparoscopic or robotic surgery.
On whom is it suitable?
A recent paper has confirmed that even if the cancer is through the capsule it is still possible to clear all the cancer (a negative margin) and preserve the erection nerves. The reason why this is possible is because most cancer only penetrates 1-2mm outside of the capsule, still leaving it possible to clear the cancer and preserve the nerve and secondly, most positive margins (areas where the surgeon comes too close to the cancer) are not where the erection nerves are but rather at the tip of the prostate (apex of the prostate).
Am I suitable?
Pre-operatively, information about the cancer such as the grade of the cancer, the extent of the biopsies (both number and percentage) as well as the presence of perineural invasion and the presence of palpable lumps in the prostate all are taken into consideration. As well as this, one carefully considers the status of the patient's sexual function and more recently, the use of endorectal MRI can help in deciding whether cancer is involved in the nerves or not.
A final decision on who to spare nerves is made at the time of surgery by an experienced surgeon using both visual and tactile input. The technique is critical. When the layers surrounding and attached to the prostate become very thickened, then the nerves are sacrificed. Furthermore, if after removal of the prostate there is concern that not all the cancer has been removed, then the nerve is sacrificed. In my own hands, over 85% of all nerves are preserved whilst still keeping the positive margin rate extremely low, thus not compromising the chance of cure.
Generally, I have a high index of suspicion that a nerve will have to be sacrificed if the PSA is greater than 10, the Gleason score greater than or equal to 4+3=7 or a high percentage of involvement of the cores are involved on one side. As every patient's anatomy is different, the final decision as to preserving the nerve is left until the time of surgery.
How is it done?
Nerve sparing radical prostatectomy is one of the most technically challenging operations in all surgery. As the nerves are not myelinated, they are particularly susceptible to injury. Critical factors in the surgery are the gentleness of the surgeon, the use of magnification, the avoidance of cautery or any thermal energy and the experience of the surgeon. The use of the cavermap, which is an electrical device to localise the nerve can also be useful in selective cases. It can help locate the nerve when one is unsure and also establish whether the nerve has been damaged at the end of the procedure.
Three factors have a strong influence on the recovery of sexual function following radical prostatectomy: the age of the patient, the pre-operative status of sexual function and the surgical technique. At St Vincent's I recently carried out and presented a patient reported outcome study on men with normal sexual function pre-operatively evaluating their status post radical prostatectomy with a validated quality of life survey performed by an independent third party. With a follow up of between 12 and 24 months, 73% of patients were potent following nerve sparing surgery, whilst in the under 60 year old age group 84% of patients were potent. Potency was defined as the ability to have intercourse on most attempts with or without the use of Viagra-like substances. International results of potency after radical prostatectomy have been extremely variable depending on how and when the study has been done, results varying from 10-80% of potency.
There are currently a number of efforts using Viagra, Cialis or Levitra in the early post-operative period to speed up recovery of sexual function. Padma Nathan et al recently published a paper that suggested that daily Viagra use for nine months after nerve sparing operation recovered their erections more rapidly. Dr Francesco Montorsi from Milan, Italy, reported in 1997 that using regular penile injection immediately after nerve sparing surgery improved the chance of recovery of erections also. My current practice is to recommend the use of either tablets or injections in the early post-operative period to improve the chance of erection recovery.
Associate Professor Stricker's Nerve Sparing Results
A/Prof Stricker has the largest series of nerve sparing prostatectomies in Australia. He has specialized in the technique of preserving the erection nerves even in some patients with more aggressive cancers. From his overall series of over 1500 radical prostatectomies, his research team have regularly updated his results over the last 20 years. With his current technique which he has developed after many modifications his current rate of potency (erection) recovery when patients are suitable for full nerve sparing are as follows:
These results have been presented at multiple national and international meetings.
He has been able to achieve this without affecting the potential cure rate (positive margin rate has remained below 10%.