Education And Debate

Controversies in Management: Alternatives are still unproved

BMJ 1994; 309 doi: https://doi.org/10.1136/bmj.309.6956.717 (Published 17 September 1994) Cite this as: BMJ 1994;309:717
  1. M C Bishop
  1. City Hospital, Nottingham NG5 1PB.

    For many years transurethral resection of prostate has been established as the optimum treatment for benign prostatic hyperplasia. This viewpoint is now being challenged because of criticism of the operation itself and by the availability of a bewildering variety of alternative treatments (box). Most are recent innovations, and results of long term follow up studies are not yet available. Unfortunately, claims for their superiority have sometimes been exaggerated by their enthusiastic proponents.

    Treatments for benign prostatic hyperplasia

    Physical

    Balloon dilatation

    Intraurethral implants - Spirals, stents

    Microwave thermotherapy - Transrectal, transurethral

    Laser - “Side fire” ablation, contact incision, transurethral needle ablation

    Ultrasonic tissue - External source

    Disintegration - Transurethral probe

    Cryosurgery Transurethral resection or incision of prostate

    Pharmacotherapy

    (alpha) Adrenergic antagonists - for example, prazosin, indoramin, terazosin, doxazosin

    Antiandrogen treatment - Surgical castration, medical castration (luteinising hormone releasing hormone analogues, cyproterone, flutamide

    Specific prostatic androgen inhibitor - 5(alpha) reductase inhibitor (finasteride)

    Mortality and morbidity

    Recent reports of an unexpectedly high incidence of complications after transurethral resection of prostate need to be taken seriously, but few would agree that the early and late mortality figures published by Roos et al are typical of modern practice.1 Mortality is influenced by many factors that have not necessarily been evaluated or reported but could bias results. More obviously these include the skill and continuing experience of the surgeon, the size of the prostate resected (which in turn influences duration of resection and hence blood loss and irrigant absorption), and cardiovascular disease. Clearly, these factors should be quoted in trials of new treatments tested against placebo and transurethral resection. Nowadays, the short term operative mortality should be 0.3% or less for most groups of patients.2

    The possibility that an operation could affect survival months and years later seems far fetched. However, there is some evidence for subclinical cardiac disturbance during transurethral resection which might limit the myocardial reserve to withstand subsequent ischaemia.3 This issue remains controversial, and a recent study showed 2.8% mortality during 12 months after transurethral resection of prostate,4 which is half the rate that would be expected in a group of age matched elderly men.

    Strictures of the urethra and bladder neck occur in about 10% of patients after transurethral resection. This figure could be an underestimate since restriction of urethral calibre does not necessarily reduce flow if there is compensation by the detrusor. Strictures also complicate any procedure which requires urethral instrumentation, and they can therefore be expected to occur with any one of the new physical methods of destroying prostatic tissue.

    Most of the 25% of patients who are dissatisfied with transurethral resection of prostate complain of persistent frequency, urgency, and perhaps incontinence.5 Most will have suffered these symptoms before surgery and will have severe secondary detrusor instability, perhaps with borderline obstruction. Symptoms of instability persist in 10% of patients, and arguably the operation was inappropriate for them.

    The dissatisfaction of a further 10% will be due to detrusorfailure. Such patients may not have been obstructed before the operation. It is unlikely that either group would have fared better with other physical methods of treatment or drugs.

    About 70% of patients who have transurethral resection of prostate will have retrograde ejaculation. Most are unconcerned provided that the symptoms are explained adequately beforehand and they are reassured that orgasm can be achieved. The risk of impotence is difficult to assess. In general studies on sexual dysfunction have been unsatisfactory because of a lack of objectivity and few prospective studies exist. Impotence is unlikely to occur as a new symptom in more than 10% of patients. This should be considered in the context of an aging population with naturally waning potency.

    Other physical treatments

    At present transurethral resection of prostate must remain the basis for comparison. There is no other feasible treatment which removes most of the obstructive tissue. This can be proved urodynamically by a large rise in flow rate and, provided that detrusor function is adequate, abolition of residual urine.6 Laser ablation and perhaps ultrasonic tissue disintegration show promise of relieving obstruction with minimal blood loss, anaesthetic risk, and length of hospital stay. The same could be achieved with hyperthermia but at the risk of damaging surrounding structures. More modest but acceptable temperature rises during microwave therapy do not greatly improve voiding dynamics but, surprisingly, can improve symptoms of detrusor instability.7 Better flow rates can be achieved with coils and stents, but there is increasing agreement that any advantages are outweighed by the potential complications of an expensive indwelling foreign body.

    Both (alpha) receptor antagonists and finasteride improve symptom scores but so does a placebo. Not surprisingly, when objective criteria are used the results are disappointing. Although impressive and statistically significant changes in flow rates and residual urine volumes are claimed, in absolute terms they are trivial. Drugs must be taken continuously and, in the case of finasteride, for a minimum of six months to achieve maximum effect.

    The recent promotion of male health, focusing on early diagnosis of prostatic hyperplasia, is heavily supported by the pharmaceutical industry. It implies that nipping early prostatic enlargement in the bud with drugs will avoid the need for transurethral resection of prostate. But the outcome of untreated benign hyperplasia is unpredictable. It does not necessarily lead to complications or even worsening symptoms.8 Marketing of “awareness” of benign prostatic hyperplasia can bring men's attention to previously unnoticed modest symptoms. But such an approach is questionable until controlled trials have shown real benefits. Despite treatment with finasteride the prostate continues to grow, though more slowly than normal. However, obstruction of the bladder neck is poorly related to the size of the prostate, and drugs are therefore unlikely to prevent acute retention, or, more importantly, the insidious syndrome of chronic retention and obstructive nephropathy.

    Finasteride is expensive. The long term side effects of even a mild antiandrogenic drug are unpredictable. Impotence certainly can occur, osteoporosis is possible, and even with the creative use of mathematical corrections of plasma prostate specific antigen concentrations long term treatment with finasteride could delay the diagnosis of carcinoma of the prostate.

    Conclusions

    S

    Patients with moderate prostatism, most acute and chronic retention, and complications of bladder outflow obstruction, such as calculi and recurrent infection, will continue to require transurethral resection of prostate for many years. In experienced hands the operation is safe and effective. (alpha) Blockers and finasteride might be helpful if a long delay before surgery is expected. Patients with mild prostatism are best left alone.

    Commentary: patients must decide

    Benign prostatic hyperplasia is common, and both authors agree that in its milder forms no treatment may be necessary. When intervention is required there is a bewildering array of possibilities. Essentially the approach taken will depend on one patient's preference, although information available on some of the newer pharmacological and minimally invasive treatments is rather limited. The encouraging preliminary results results with (alpha) blockers and finasteride are likely to make these drugs increasingly popular, and the use of drugs initially does not preclude later surgical intervention if needed. A lot is known about the benefits and deficiencies of transurethral resection of prostate, and in contrast the new approaches are currently looking appealing. But more time is needed to assess these new techniques before transurethral resection of prostate is abandoned.—PETER J RUBIN, professor of therapeutics, University of Nottingham

    References

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