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RADIOLOGY IN D I S E A S E S OF THE P R O S T A T E

BY ASHTON MILLER, M.A., M.D., F.R.C.S. UROLOGIST, UNITED BRISTOL HOSPITALS

THE purpose of this communication is to describe the point of view of the clinical urologist. There is little point in discussing the several rarities in which radiology plays a useful part, such as congenital bladder-neck obstruction and tuberculous prostatitis, so attention is confined to the two most important conditions--benign prostatic hypertrophy and carcinoma of the prostate.

PROSTATIC HYPERTROPHY Intravenous pyelography forms part of the routine investigation and assessment of all patients

complaining of symptoms due to an enlarged prostate, with the exception of those in whom a severe degree of renal failure makes the examination useless. Before discussing the value of intravenous pyelography, the routine examination of such a patient will be described.

The history of the complaint is taken, paying particular attention to its length, for it is unusual to find a patient with benign hypertrophy who cannot go back a matter of years to the insidious onset of his symptoms, while a history measured in weeks or months makes one think of malig- nancy, though here it is necessary to mention the occasional onset of acute retention of urine without preliminary micturition disturbance as an exception to this generalization. The pre- dominant symptom is usually frequency of micturition, with nocturnal frequency the most annoying par t ; urgency and delay in starting are also common. Diminution in the frequency of micturition or loss of control may often indicate the development of a large amount of residual urine because of loss of detrusor power of the bladder. Each patient is questioned about h~ematuria, because although about io per cent of them see blood in the urine which originates from the prostate gland itself, an F~g I4I.--Enlarged prostate and bladder tumour in the same

pa t i en t . occasional patient may have a growth in the kidney or in the bladder masquerading behind prostatic symptoms; urologists are expected to be aware of these possibilities (Fig. I 4 I ).

At the clinical examination we tend to assess these patients in two separate ways, which are then correlated. Very important, firstly, is the general examination of the old patient ; all these patients are ' part-worn ' by reason of their age, and it is not that we have to say what ought to be done-- that is usually easy--but often how much can safely be done: The age on the case sheet matters little; such investigations as the electrocardiogram and the chest radiographs are often only of academic interest, for we have to try and assess the ability of an old man to withstand a major operation involving ansesthesia, blood-loss, and temporary immobilization, and for this purpose the ordinary methods of simple clinical bedside examination are undoubtedly the best available. Secondly, examination of the urinary and genital organs reveals the particular abnor- mality we have to treat ; we may find the enlarged kidney or distended bladder, the enlargement of the prostate, and sometimes the urethral stricture ; the urine may be clear or infected, perhaps containing sugar or blood.

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It is here that the intravenous pyelogram plays its part because clinical examination reveals only the gross abnormality, and it is necessary for us to be able to detect early arid less obvious changes. In many patients we can feel the kidney only when it is considerably enlarged; the ureters cannot be felt, and the distended bladder cannot be felt until it contains more than about 25o c.c., even in a thin patient. By rectal palpation of the prostate one can estimate accurately the size of the extravesical prostatic enlargement, but the middle lobe which projects into the cavity of the bladder cannot be felt. I t may be said, therefore, that the information required

Fig. 242 . - -Re t rog rade pyelogram of a renal tumour m a Fig. 143.--Unexpected f inding of a ' silent ' s taghorn calculus pat ient wi th prostatic symptoms, including heematuria, in a pat ient wi th an enlarged prostate.

from the radiologist is to a large extent a refinement of the ordinary methods of clinical examina- tion of the urinary tract and may be considered under headings as follows : - -

I. R e n a l A n a t o m y . - - I f the urologis(knows that he is dealing with a normal upper urinary tract he can often take liberties with the lower tract, but if abnormalities of the kidneys exist his hands are tied, so he wants to know that both kidneys are present, that they are not hydronephrotic, and-- to quote an illustration of an alternative cause for h~ematuria in a man with prostatic enlarge- ment- - tha t they do not contain a growth or stone (Figs. 14.2 , i43 ).

2. R e n a l F u n e t i o n . - - J u s t as important is the knowledge that both kidneys are secreting and concentrating well. Traditionally the blood-urea level is a good renal function test, but it must be remembered that renal function must be greatly reduced before its level rises ; the urea clearance must in fact be below 30 per cent of normal. Also, raising of the blood-urea level will give no indication of its cause, which 'might possibly be chronic pyelonephritis or hydronephrosis due to back-pressure.

When the blood-urea level has risen above the normal upper limit but below about i2o mg. per cent one can expect to have enough concentration of dye to produce a shadow which will

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indicate the nature of the kidney disturbance, although above 8o mg. per cent the shadow will necessarily be very faint. It is useful to know whether a hydronephrosis exists (which may be expected to recover if adequately drained), or a nephritis or pyelonephritis, indicating renal failure without obstructive dilatation, which will not recover under any circumstances. The intravenous pyelogram gives a good visual record of improvement following drainage and is more reliable than the blood-urea as a clinical guide.

3. Ureterie Funetion.--Stasis in the lower ends of the ureters or persistent filling of the whole length of both ureters in the presence of good secretion usually goes with a significant amount

Fig. I44.--Chronic retention of urine wlth ureteric stasis.

Fig. I45.--Vesical calculus complicating prostatic enlarge- ment.

of residual urine in the bladder, and is a warning that the beginnings of renal failure are imminent (Fig. i44 ).

4. Bladder A n a t o m y . - - A thick-walled bladder results from long-continued obstruction to the evacuation of urine and goes with gross trabeculation and saccule formation. Knowledge of this helps in two ways ; we know for sure that we are dealing with a purely obstructive lesion and that there is no question of an atonic or paralytic bladder, and it also warns us to beware of infective complications following operation, because stagnant blood-clot and urine in deep saccules is equivalent to residual urine and easily infected.

Again, and more important, there is the triad of stone, growth, and diverticulum in the bladder. These three things are the classical complications of the enlarged prostate, and woe betide the su.rgeon who depends upon luck to help him to avoid them. In the presence of the enlarged prostate the stone, growth, or diverticulum almost always requires treatment before the prostate as a staged procedure, so it is very important to locate it before the patient reaches the operating

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table. It may be said that all these things are easily visible with the @stoscope and all sensible surgeons pass a cystoscope before they remove a prostate, but the answers to this are : - -

i. I t is highly undesirable to perform cystoscopy in the presence of a very enlarged prostate before the actual time of operation because of the danger of inducing acute retention.

Fzg. I47--Pap~lliferous carcinoma of bladder complicating prostatic enlargement.

Fzg. i46 . - -Vemca diver t iculum and residual ur ine resulting f rom prostatic obstruztlon.

2 . It is impossible t o a s s e s s the size of Fig. I48 . - -Radiographs of a bladder filled with 2, 4, and 6 oz. of fired.

a diverticulum with the cystoscope. 3- Surgeons who do their prostatectomy through the open bladder do not usually pass a

cystoscope first. ," The cystogram or the intravenous pyelogram will often provide enough information to allow

a diagnosis to be made ; in the case of stone and diverticulum this is practically always true, but when a turnout is present one is not often so fortunate (Figs. i45-I47).

5. B ladder F u n c t i o n . - - J u s t as it is not advisable to pass a cystoscope, so is it unwise, in my opinion, to pass a catheter to measure residual urine, for the same reason. The intravenous pyelogram makes it unnecessary ; it is possible to detect 6 oz. or more of residual urine by clinical examination, but a true residual amount of more than 3 oz. is probably significant in the patient with an enlarged prostate and this can be seen on a radiograph. Another point which will readily be appreciated is that it is obviously desirable to spare an old man the discomfort of instrumenta- tion, which may be considerable even with a local anesthetic (Fig. I48 ).

6. Pros ta te A n a t o m y . - - T h e filling defect caused by the intravesical projection of middle- lobe or collar enlargement supplements the rectal examination findings but does not add a great

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deal to them. The extravesical enlargement is the important part which is readily palpable; the presence of a large intravesical projection together with a small prostate may sometimes influ- ence one's personal choice of retropubic prostatectomy instead of transurethral resection, but

Fig. I49.--Prostatic calculi.; note the elevation of the internal urinary meatus,

Fig. iSo.--General ized osteoblastic metastases m s panent with an apparently benign prostatic enlargement and normal serum acid phosphatase.

otherwise is of little moment. It is important to emphasize that the presence of such a vesical filling defect should never lead the clinician to neglect the rectal findings.

The knowledge that the prostate contains calculi may often be of great help in deciding whether a hard area in the prostate is or is not malignant, especially when, as happens frequently, long- standing chronic prostatitis coexists with calculi (Fig. I49 ).

CARCINOMA OF PROSTATE

All that I have said about benign prostatic enlargement applies to carcinomatous obstruction, with the addition that occasionally the radiologist has the pleasure of making the diagnosis for certain by finding metastases in bone ; but it is true to say that the educated finger is still the best method of diagnosing carcinoma in this organ (Fig. 15@

Cysto-urethrography we find most useful when, in a patient with post-prostatectomy obstruc- tion, it is impossible to introduce a urethral instrument. It cannot take the place of the cysto- urethroscope.

SUMMARY

The clinician uses the intravenous pyelogram because : - - 1. It is an excellent renal function test. 2. It reveals unsuspected complications in kidneys, ureters, and bladder. 3. It makes estimation of residual urine by instrumentation unnecessary.