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On the Pathology of Enlarged or Hypertrophied

Prostate.

BY REGINALD HARRISON, F. R. C. S.,

Surgeon to St. Peter's Hospital, London.

T IS now some years since I brought under the notice of the profession† certain views that had been gradually forcing themselves upon me, in reference to the pathology of enlarged or hypertrophied prostate as we see it coincident with advancing years. These opinions were for the most part, formed in connection with the surgery of the part in which I have been considerably engaged. Without wishing to occupy space by quotations I might adduce from various writings, I cannot help recognizing that these views seem to have commended themselves to many, and are further supported by facts which are difficult to explain by any other hypothesis.

It is hardly necessary for me to state that since these observations were put forward important changes have been made in the manner of examining the prostate, and of dealing with it when it is found to be in certain states of disease, by the introduction and general acceptance of the supra-pubic method of exploration. We have within this period been brought, so to speak, face to face with the enlarged prostate, and our means of testing matters of opinion have been extended. I do not shrink from the increased light that has thus been thrown upon the whole subject, but shall hope in the course of this paper to show that my views in reference to this question have thereby been strengthened. It will be necessary for me to make a few prefatory remarks.

In advocating what I would speak of as the muscular theory in explanation of hypertrophy of the prostate, I am not aware I ever denied that the prostate was dissociated from the genital function. I have referred to it as "a muscle containing a tolerably large proportion of glandular or secreting tissue embedded in it," and though failing to see evidence showing that it is engaged in elaborating the secretion of the testicles, I adopt the view of Dr. Handfield Jones‡ expressed in the following words. Its function relative to the sexual act is "in supplying a vehicle which enables the fecundating fluid to act with greater certainty over a larger area, whilst at the time it supplies a muscular buttress against which the ejaculatory muscles of the urethra may advantageously act in the emission of the semen." It is, therefore, I believe, to this extent, a compound organ, and I am not aware

The Causation and Nature of Hypertrophy of the Prostate; Lancet, March 6, August 28, and December 4, 1886. London Medical Gazette, Vol. V, 1847.

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that any one has ventured to bring forward any arguments contravening this limitation of duality. Nor shall I have occasion to call in question the structural composition of the parts, as now generally accepted. It is the function of the prostate and what arises out of it that I shall confine my attention to here.

It would seem in the face of the study that has for centuries, I may say, been devoted to this pathological problem by many of the most ardent workers that have adorned our profession, somewhat venturesome on my part, and no one feels this more than I do myself, to offer anything which may be regarded as a possible explanation of a change so remarkable and yet so constant. Still, however, there appear to me to be facts which tend to point in one direction, and from the interpretation of which, truth in some degree may eventually come, if not by me, at all events out of the reflections that the consideration of such facts may suggest to others.

I have just stated that I regard senile enlargement of the prostate as an example of a muscular hypertrophy analogous with other similar kinds of overgrowth, and arising out of the muscular functions in which the part is unceasingly engaged. It is of the first importance that the muscular action of this organ should be clearly established, for unless this can be done the whole of my argument necessarily falls to the ground.

The difficulty that has hitherto arisen in providing this explanation, is in some measure due to the isolated manner in which the prostate has been studied. It has suffered, if I may be allowed to say it, by being too much specialized, and a tendency has naturally arisen to regard it as an individual and independent organ, and not in the light of a component part of a system of never-ceasing activity.

Analogies, when based upon correct interpretations, are often of much assistance in the study of some apparently abstruse laws governing pathological processes. How absolutely impossible, for instance, it would be to understand or explain hypertrophy of the heart or those local changes which occur in some of the blood vessels, unless those parts were regarded not as so many chambers or tubes but as component portions of a single circulatory system, and it is in this way that the interpretation of the function and pathology of the prostate has to some extent suffered. It has been urged that though the prostate is, in some measure, engaged in the process of micturition, the fact that it is used for this purpose half a dozen times or so in the twenty-four hours is hardly sufficient to account for its own growth. This, I would emphasize, is merely the casual part the organ plays in what we generally regard as a voluntary act.

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Such a limited view as this implies is, in a large measure, due to the habit we have acquired of taking our ideas of the living organ from the condition it presents after death, when removed from the body in a more or less contracted state, somewhat resembling a Spanish chestnut in shape. This is no more like the living prostate than the dead heart resembles the one in full vigor and activity. The prostate assumes, I believe, no such appearance during life, except on the rare occasions when the bladder is absolutely empty, but on the contrary, the muscular fibres of which it is so largely composed are spread out like a funnel, so as to furnish a contractile support for the bladder, as well as its varying contents. This disposition is probably best appreciated by examination by the rectum when the patient is in the erect and semi-erect positions, with the bladder empty, as well as in various degrees of repletion.

Though the existence of a prostate is not limited to man, I am not aware that in any animal it undergoes a change analogous with the senile enlargement, as observed in the human species. Hence, though enlargement of the prostate and the habit of maintaining the erect position may be mere coincidences, this fact cannot be allowed to pass unnoticed.

And as the normal prostate is in this funnel-shaped manner spread out, so is it when it is enlarged. We are often surprised to find after death, or by a supra-pubic incision, how much smaller the prostate turns out to be as compared with what it was when examined during its functional existence. by the finger in the rectum. Unless this continuous muscular action of the prostate in supporting the contents of the bladder in accordance with the degree required, as well as in minimising the effects of shock applied to the body, is fully appreciated, it is impossible to understand how the functions of the viscus can be discharged without some other provision than that afforded by a mere fibrous floor.

And I would here remark that it was not until I recognized the funnelshaped manner in which, during life, the prostate was disposed in contradistinction to the contracted mass presented after death, that I could find no explanation for certain results following different lesions of the part, as for instance, in the various perineal incisions made for the removal of stone by lithotomy. Why an incision into the prostate radiating from the urethra passing through it, and not, as a rule, dividing more than one-third of the solid mass presented by the dead prostate, should be followed by absolute incontinence of urine for some days, seemed difficult to understand when so much of the circumference remains intact. Such a result, however, at once became tangible when we recognized that the incision, though limited, absolutely destroyed, until repair took place, the capability of a cone-shaped muscle to contain fluid.

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I have said the male bladder, as in its mechanical arrangements it has little in common with that of the opposite sex. In the latter the process of micturition and the axis of urine pressure relative to the pelvic outlet are different, whilst there is an absence of provision for ejaculation of semen, or even any direct connection with the genital function. In the female the manner in which the bladder is supported when distended, has a resemblance to what is found in some quadrupeds.

Further, the surgery of the part furnishes evidence in various ways of the muscular power of the prostate, some of which I will briefly mention. Openings may be made into the urethra in any part of its course as high up as what we term the apex of the prostate, without incontinence of urine following. In cases of lithotomy by the median operation patients often retain full control over the bladder during the whole period of their convalescence, in spite of the dilatation to which the prostate has been subjected by the introduction of the finger and the extraction of the stone. Directly, however, the knife impinges to any appreciable extent on the prostate, as in the lateral operation for stone, incontinence from that moment takes place; the patient has no command over his urine, he can neither collect nor expel it; and in this condition he remains until the healing process has made considerable advance. Some instances I have examined where permanent incontinence of urine followed the operation of lateral lithotomy appear to have been connected with the complete division of the prostatic circumference by too free an incision. I can hardly see how such a consequence as this could happen if the prostate, during life, presented the appearance of the contracted mass we are accustomed to look at after death.

In cases of extroversion of the bladder where there is no receptacle for the urine, the prostate is met with only in a rudimentary form. In advanced life, so far as I have been able to ascertain, hypertrophy never occurs in these malformations, though their sexual desires are often vigorous.

I have recorded a case* where incontinence of urine in a boy appeared to be associated with an arrest in the development of the prostate. This, however, may merely be a coincidence, as at this period of life this part exists only in a very rudimentary form.

In an instance of excision of the entire prostate I performed for malignant disease, although the patient recovered completely from the operation. and lived over fourteen months afterwards, during the greater portion of which time he followed an active and laborious occupation, control over the bladder was lost. To provide against the incontinence the patient was

*Surgical Disorders of the Urinary Organs, Fourth Edition. 1893. Churchill.

+Ibid (To preceding foot-note )