Ben Lamb and Saiful Miah are Urologists specialising in prostate cancer surgery
I have previously given some of my views on quality in surgery, or how you know whether your surgeon is right for you (see How do I know if a surgeon is any good?). One of the main determinants of quality is patient outcomes. Patient outcomes include whether the surgery has been effective (e.g. removed a tumour), and to what degree patients have experienced side effects (e.g. urinary symptoms). Some outcomes can be objectively measured (e.g. with a blood test, or scan). Sometimes, objective measurement is not feasible (e.g. sexual function). Outcomes that cannot be objectively measured can be reported by patients using validated questionnaires. Asking patients to report how they are is less biased than asking surgeons how their patients are. These validated questionnaires, or patient reported outcome measures (PROMS) can be collected by the surgical team before and after surgery, and later during the follow-up period. Sometimes, complication rates are reported alongside outcomes to give a clearer picture of quality.
What outcomes are important when considering a robotic assisted radical prostatectomy (RARP)?
Patient outcomes after RARP can be divided into five key domains, collectively termed the ‘pentafecta’. [1]
- Complications
- Surgical margin status
- Urinary control
- Sexual function
- Prostate cancer control
Below, I have listed each domain and how they can be measured.
Complications
Complications can occur during or after robotic radical prostatectomy. One of the advantages of a robotic operation is that the complication rate tends to be lower than open or conventional keyhole (laparoscopic) surgery. There is good evidence that surgeons undertaking higher numbers of RARP cases (more than 50 per year) in centres undertaking higher numbers of complex operations (more than 100 per year) have lower complication rates. [2] This is probably because the whole team (ward nurses, anaesthetic staff, specialist nurses) all become up-skilled by increased experience. As I have previously described, complications also depend on patient-factors, such as age, other health conditions, and the severity of the disease. The British Association of Urological Surgeons publishes the complication rates of all urologists performing RARP in the UK. [3]
Problems relating to surgery and general anaesthetic: These include chest infection; stroke; or heart attack. These are rare.
Blood loss: Severe bleeding may require a blood transfusion or another operation. This occurs in less than 1 in 100 of cases.
Infection: urinary infection from the catheter occurs occasionally (approximately 1 in 20). Generally, this can be managed with antibiotic tablets.
Wound problems: Infection (1 in 20) or hernia (1 in 100) can occur at the wound sites.
Blood clots in the legs or lung (deep vein thrombosis, or DVT): This occurs in 1 in 50 to 1 in 100 cases. Treatment with a blood thinning medication is required for a period of 3-6 months.
Internal urine leak: Occasionally (1 in 50), when the catheter is removed the join between the bladder and the urethra may leak. This can cause some discomfort, and the catheter may need to be reinserted for another week or so.
Bladder neck/urethral scarring: occasionally a narrowing of the urethra (about 1 in 25) or the neck of the bladder (about 1 in 100) can occur in the months after surgery. A further operation may be required to correct it.
Injury to your bowel or rectum: Very rarely (approximately 1 in 1000) there may be injury to your lower bowel during surgery. Sometimes a temporary colostomy may be required to improve healing. Death: This is very rare. Approximately 1 in 1000 of patients die from complications of surgery.
Surgical Margin Status
The main aim of RARP is to remove all the prostate cancer. As it is not possible to check the tissue that is left inside for prostate cancer cells, the completeness of the removal of the prostate cancer is judged on having no exposed cancer at the outside of the removed prostate. This is known as having clear surgical margins. If cancer is seen at the outer surface of the prostate, it is called a positive surgical margin. The problem with a positive surgical margin is that we cannot be certain that we have not left some cancer cells inside. For this reason, in some patients having a positive surgical margin is associated with a higher chance of prostate cancer recurrence. [4] Sometimes, however, cancer cells may become exposed at the edge of the prostate due to the way it is handled during surgery. In this case there may be no additional cancer remaining inside. This is more likely to be the case if nerve-sparing surgery is performed. The chance of a positive surgical margin is approximately 1 in 10 if the cancer is confined to the prostate (stage T2), and 1 in 3 if the cancer is coming out of the prostate (stage T3). The results of the operation will be discussed at your first appointment after surgery. If a positive surgical margin is present your surgeon should be able to discuss whether this is likely to be significant or not. A positive surgical margin may increase the risk of requiring additional treatment in the future.
Urinary control
Loss of urinary control is one of the major problems following radical prostatectomy and is a concern for patients with prostate cancer when making decisions about their treatment. Following RARP, most men experience some problems with urinary control, but for the majority this is a temporary problem. After the catheter is removed most men will need to wear a pad in their underwear to catch any leaking urine. Urinary control improves with time, with 40 in 100 men not needing to wear any pads, and a further 45 in 100 men using a single pad for the whole day. By 6-months after surgery, 85 in 100 men are pad-free, approximately 10 in 100 using one pad per day, and the remaining 5 in 100 using more than 1 pad. By 1 year after surgery, over 90 in 100 of men are pad-free, with approximately 5 in 100 using one pad, and 3 in 100 more than 1 pad per day. Further improvements in control are seen beyond one year.
All men are advised to perform pelvic floor exercises following catheter removal (starting these exercises before surgery can also help to increase familiarity and tone the necessary muscles). The pelvic floor muscles are used to consciously hold on to urine in the bladder and reduce leaking. For most men leaking occurs when they move around or strain (e.g. when coughing or lifting something heavy). Tensing the pelvic floor during these activities helps to reduce leakage. In addition, reducing intake of drinks that can increase bladder activity (e.g. caffeinated drinks such as tea, coffee, green tea, cola, energy drinks) can help as urinary control improves.
If urinary control does not improve to a level that men are happy with, further surgery can be performed to correct this. Surgery for urinary incontinence includes insertion of a male urethral sling, or an artificial urinary sphincter, and is performed in up to 4 in 100 men. In general, if patients are requiring 0-2 pads per day at three-months following RARP, then the chances of needing such surgery is very low. Modification of the RARP technique have been shown to improve post-operative urinary control. For example, minimising dissection of some of the structures that support the bladder and urinary sphincter can speed up recovery of continence. Retzius sparing radical prostatectomy is an example of this approach. During a Retzius sparing RARP (rsRARP), the prostate is removed from beneath the bladder, allowing the bladder and supporting structures to stay in their natural place. In the short term, urinary control improves more rapidly than with conventional technique, with about 8 out of 10 men being pad-free at 6-weeks after surgery, and all men pad-free by 6-months. This approach is relatively novel, and long-term data regarding patient outcomes is needed.
Sexual function
Several changes in sexual function occur after RARP. Many people consider only the effect of surgery on erectile function, but there are a number of after effects.
Dry orgasm: the prostate and seminal vesicles produce most of the seminal fluid. Following RARP no semen is produced during orgasm. This can have an impact on future fertility for men undergoing RARP. Semen preservation before RARP is advised if you are considering trying to father children in the future.
Sensation and orgasm: the sensation of the penis and ability to climax are relatively well preserved following RARP. Orgasm may feel different as there will be no ejaculation, and erections may be affected. There may also be some leak of urine at climax (climacturia) for some patients.
Penile length: the penis is usually slightly (1-2cm) shorter following RARP. This is thought to be a result of re-joining the urethra to the bladder. There is some evidence that the penis returns to it pre-operative length after a period of a few years. Use of a penile vacuum device following surgery can help to restore and preserve penile length.
Erectile function: Erections rely on having both healthy blood vessels (cavernosal arteries) and nerves (pelvic parasympathetic nerves) to the penis. These run through the pelvis, close to the capsule of the prostate as the neurovascular bundles. The degree to which erections are preserved or return after surgery depends on a number of factors. These include erectile function before surgery, other health conditions that affect the blood vessels or nerves to the penis (e.g. high blood pressure or diabetes), whether nerve-sparing surgery is performed and the use of treatment for the recovery of erections (penile rehabilitation).
You can think of the neurovascular bundle as being like the skin of an orange enclosing the fruit, which is the prostate. If you want to pick up the orange, you can take it with the skin left on. If you want to take the fruit and leave the skin behind, some trauma to the skin is inevitable. Given their proximity to the prostate, it is common for the neurovascular bundles to be affected at the time of RARP, which then effects the quality of erections after surgery. If you peel the fruit carefully, however, the skin could be left largely intact. This is the idea of nerve-sparing in RARP, intended to preserve the neurovascular bundles, and improve recovery of erections after surgery.
If the cancer is lying at the edge of the prostate, close to the neurovascular bundle it is often advisable that the neurovascular bundle is completely, or partially removed with the prostate (taking out the orange with the skin on). This is so that the cancer remains covered so that it is completely removed. Nerve sparing in this situation could result in cancer being exposed at the edge of the prostate (positive surgical margin), which means that the possibility that some cancer cells have been left behind cannot be entirely excluded.
Accordingly, nerve sparing can be performed on none, one or both sides of the prostate. It could be full- (intra-fascial nerve spare) or partial- thickness (inter-fascial). The surgical plan will depend on discussion between the patient and surgeon regarding priorities (cancer control and return of sexual function), current sexual function (how are the erections to start with) and also what is technically feasible. The more of the neurovascular bundles are preserved, the better the recovery of erections.
Following bilateral nerve-sparing surgery, approximately 50% of men at 6 months, and 70% at 12 months and 75% at 18 months rate their erections as good, with a further slight increase in time. For men who have undergone unilateral nerve spare, these figures are 15%, 25% and 60%. Men undergoing non-nerve sparing surgery only 5%, 15% and 15% report good erections at the time points above.
In order to improve recovery of erections, I recommend all patients undergoing RARP to start a medication to help improve the penile blood supply (tadalafil, or Cialis) once their catheter has been removed. This is usually taken as a small bedtime dose (5mg) every day. This appears to accelerate recovery of erections. In addition, I recommend use of a vacuum erection device (penile pump) on a regular basis: twice daily as an exercise, and/or prior to sexual activity. Using a penile pump maintains penile length, helps to prevent negative changes in the penile tissues until natural erections return, and can improve the quality of erections.
Spontaneous (natural) erections don’t return for about 1 in 3 patients. Some men expect and accept this, and do not request further treatment. If further treatment to recover erections is desired, it can be given using medication applied to the penis (as a cream or gel, a tablet passed into the urethra, or an injection), or an artificial implant.
Prostate cancer control
Prostate cancer control can be measured in several ways, including PSA test results, the need for additional cancer treatment, scan results, and even death from prostate cancer. Fortunately, most men are cured of prostate cancer following RARP. If the prostate cancer does recur after surgery, the first sign is usually in the PSA test.
The PSA test following surgery provides a reliable estimate of cancer control. Usually this is first measured between 6-12 weeks after surgery. Measurement before this time can be misleading, as the PSA already in the blood can persist for some time. It is desirable for the first test result to show a PSA level of less than 0.1ng/ml. Further PSA tests are then done every 3-4 months for the first two years, then 6 monthly for another 3 years. From 5 years after surgery the test can be taken annually.
Biochemical recurrence is the term used when the PSA rises following treatment for prostate cancer. The standard level following radical prostatectomy is a rise to 0.2ng/ml. It is worth noting that biochemical recurrence usually precedes signs or symptoms of recurrent prostate cancer by many years. There is evidence, however, that additional treatment can treat recurrence and reduce the risk of future disease. Moreover, additional treatment given early is more effective than if given late. This additional treatment is usually pelvic radiotherapy (intended to treat any recurrence in the pelvis, the area the prostate used to be), or hormonal treatment (intended to treat cancer that has spread to other parts of the body). Following surgery, if the PSA fails to fall to less than 0.1ng/ml, or if it begins to show a sustained rise above this level, it is usual to be referred to an oncologist for further discussion about the merits of further treatment.
The chance of cancer control following radical prostatectomy depends on a number of factors. Factors that are useful prior to surgery include the PSA level, the stage of cancer on prostate examination or MRI scan, and the grade of cancer on needle biopsy. Following surgery, the stage and grade of cancer from the laboratory analysis of the prostate, the presence of any cancer in the removed lymph nodes, and the presence of a positive surgical margin can all affect the chance of cancer control.
In summary, the factors above are all important to ensuring the quality of care for patients undergoing radical prostatectomy. All are necessary in order to deliver a high-quality service, and none should be neglected.
References
3 https://www.baus.org.uk/patients/surgical_outcomes/
All figures were verified by the authors as accurate at the time of publication.