SURGICAL ANATOMY by Joseph Maclise

The prostate being a median structure, is formed of two lobes, united at the median line. The bulbus urethrae being also a median structure, is occasionally found notched in the centre, and presenting a bifid appearance. On the base of the bladder, P, Fig. 2, Plate 53, the two vasa deferentia, Q Q, are seen to converge from behind forwards, and enter the base of the gland; a triangular interval is thus formed between the vasa, narrower before than behind, and at the middle of this place the point of the trocar is to be passed (through the rectum,) for the purpose of evacuating the contents of the bladder, when other measures fail. When this operation is required to be performed, the situation of the prostate is first to be ascertained through the bowel; and at a distance of an inch behind the posterior border of the gland, precisely in the median line, the distended base of the bladder may be safely punctured. If the trocar pierce the bladder at this point, the seminal vessels converging to the prostate from either side, and the recto-vesical serous pouch behind, will escape being wounded. If the prostate happen to be much enlarged, the relative position of the neighbouring parts will be found disturbed, and in such case the bladder can be punctured above the pubes with greater ease and safety. In cases of impassable stricture, when extravasation of urine is threatened, or has already occurred, the urethra should be opened in the perinaeum behind the place where the stricture is situated, and this (in the present instance) certainly seems to be the more effectual measure, for at the same time that the stricture is divided, the contents of the bladder may be evacuated through the perinaeum. If the membranous part of the urethra be that where the stricture exists, a staff with a central groove is to be passed as far as the strictured part, and having ascertained the position of the instrument by the finger in the bowel, the perinaeum should be incised, at the middle line, between the bulb of the urethra and the anus. The urethra in this situation will be found to curve backwards at the depth of an inch or more from the surface. The point of the staff is now to be felt for, and the urethra is to be incised upon it. The bistoury is next to be carried backwards through the stricture till it enters that part of the urethra (usually dilated in such cases) which intervenes between the seat of obstruction and the neck of the bladder.

The lateral operation of lithotomy is to be performed according to the above described anatomical relations of the parts concerned. The bowel being empty and the bladder moderately full, a staff with a groove in its left side is to be passed by the urethra into the bladder. The position and size of the prostate is next to be ascertained by the left fore-finger in the rectum. Having now explored the surface of the perinaeum in order to determine the situation of the left tuberosity and ischio-pubic ramus, in relation to the perinaeal middle line, the staff being held steadily against the symphysis pubis, the operator proceeds to divide the skin and superficial fascia on the left side of the perinaeum, commencing the incision on the left of the raphe about an inch in front of the anus, and carrying it downwards and outwards midway between the anus and ischiatic tuberosity, to a point below these parts. The left fore-finger is then to be passed along the incision for the purpose of parting the loose cellular tissue; and any of the more resisting structures, such as the transverse and levator ani muscles, are to be divided by the knife. Deep in the forepart of the wound, the position of the staff is now to be felt for, and the structures which cover the membranous portion of the urethra are to be cautiously divided. Recollecting now that the artery of the bulb passes anterior to the staff in the urethra on a level with the bulb, the vessel is to be avoided by inserting the point of the knife in the groove of the staff as far backwards--that is, as near the apex of the prostate--as possible. The point of the knife having been inserted in the groove of the staff, the bowel is then to be depressed by the left fore-finger; and now the knife, with its back to the staff, and its edge lateralized (towards the lower part of the left tuber ischii), is to be pushed steadily along the groove in the direction of the staff, and made to divide the membranous part of the urethra and the anterior two-thirds of the left lobe of the prostate. The gland must necessarily be divided to this extent if the part of the urethra which it surrounds be traversed by the knife.

The extent to which the prostate is divided depends upon the degree of the angle which the knife, passing along the urethra, makes with the staff. The greater this angle is, the greater the extent to which the gland will be incised. The knife being next withdrawn, the left fore-finger is to be passed through the opening into the bladder, and the parts are to be dilated by the finger as it proceeds, guided by the staff. The staff is now to be removed while the point of the finger is in the neck of the bladder, and the forceps is to be passed into the bladder along the finger as a guide. The calculus, now in the grip of the forceps, is to be extracted by a slow undulating motion.

The general rules to be remembered and adopted in performing the operation of lithotomy are as follow:--1st, The incision through the skin and sub-cutaneous cellular membrane should be freely made, in order that the stone may be easily extracted and the urine have ready egress. The incision which (judging from the anatomical relations of the parts) appears to be best calculated to effect these objects, is one which would extend from a point an inch above the anus to a point in the posterior perinaeal space an inch or more below the anus. The wound thus made would depend in relation to the neck of the bladder; the important parts, vessels, &c., in the anterior perinaeal space would be avoided where the incision, if extended upwards, would have no effect whatever in facilitating the extraction of the stone or the egress of the urine; and what is also of prime importance, the external opening would directly correspond with the incision through the prostate and neck of the bladder. 2nd, After the incision through the skin and superficial fascia is made, the operator should separate as many of the deeper structures as will admit of it, by the finger rather than by the knife; and especially use the knife cautiously towards the extremities of the wound, so as to avoid the artery of the bulb, and the bulb itself in the upper part, and the rectum below. The pudic artery will not be endangered if the deeper parts be divided by the knife, with its edge directed downwards and outwards, while its point slides securely along the staff in the prostate. 3rd, The prostate should be incised sparingly, for, in addition to the known fact that the gland when only partly cut admits of dilatation to a degree sufficient to admit the passage of even a stone of large size, it is also stated upon high authority that by incising the prostate and neck of the bladder to a length equal to the diameter of the stone, such a proceeding is more frequently followed with disastrous results, owing to the circumstance that the pelvic fascia being divided at the place where it is reflected upon the base of the gland and the side and neck of the bladder, allows the urine to infiltrate the cellular tissue of the pelvis. [Footnote]

[Footnote: "The object in following this method," Mr. Liston observes, "is to avoid all interference with the reflexion of the ilio-vesical fascia from the sides of the pelvic cavity over the base of the gland and side of the bladder. If this natural boundary betwixt the external and internal cellular tissue is broken up, there is scarcely a possibility of preventing infiltration of the urine, which must almost certainly prove fatal. The prostate and other parts around the neck of the bladder are very elastic and yielding, so that without much solution of their continuity, and without the least laceration, the opening can be so dilated as to admit the fore-finger readily through the same wound; the forceps can be introduced upon this as a guide, and they can also be removed along with a stone of considerable dimensions, say from three to nearly five inches in circumference, in one direction, and from four to six in the largest."--Practical Surgery, page 510. This doctrine (founded, no doubt, on Mr. Liston's own great experience) coincides with that first expressed by Scarpa, Le Cat, and others. Sir Benjamin Brodie, Mr. Stanley, and Mr. Syme are also advocates for limited incisions, extending no farther than a partial division of the prostate, the rest being effected by dilatation. The experience, however, of Cheselden, Martineau, and Mr. S. Cooper, inclined them in favour of a rather free incision of the prostate and neck of the bladder proportioned to the size of the calculus, so that this may be extracted freely, without lacerating or contusing the parts, "and," says the distinguished lithotomist Klein, "upon this basis rests the success of my operations; and hence I invariably make it a rule to let the incision be rather too large than too small, and never to dilate it with any blunt instrument when it happens to be too diminutive, but to enlarge it with a knife, introduced, if necessary, several times."--Practische Ansichten der Bedeutendsten Chirurgische Operationen. Opinions of the highest authority being thus opposed, in reference to the question whether free or limited incisions in the neck of the bladder are followed respectively by the greater number of fatal or favourable results, and these being thought mainly to depend upon whether the pelvic fascia be opened or not, one need not hesitate to conclude, that since facts seem to be noticed in support of both modes of practice equally, the issue of the cases themselves must really be dependent upon other circumstances, such as the state of the constitution, the state of the bladder, and the relative position of the internal and external incisions. "Some individuals (observes Sir B. Brodie) are good subjects for the operation, and recover perhaps without a bad symptom, although the operation may have been very indifferently performed. Others may be truly said to be bad subjects, and die, even though the operation be performed in the most perfect manner. What is it that constitutes the essential difference between these two classes of cases? It is, according to my experience, the presence or absence of organic disease."--Diseases of the Urinary Organs.]

The position in which the staff is held while the membranous urethra and prostate are being divided should be regulated by the operator himself. If he requires the perinaeum to be protruded and the urethra directed towards the place of the incision, he can effect this by depressing the handle of the instrument a little towards the right groin, taking care at the same time that the point is kept beyond the prostate in the interior of the bladder.

FIGURE 2.

A, D, F, G, H, I, K, L refer to the same parts as in Fig. 1, Plate 52.

B.The urethra.

C.Cowper's glands between the two layers of--

E.The deep perinaeal fascia.

M.The bulb of the urethra.

Plate 52.--Figure 2.

PLATE 53.

FIGURE 1.

A, B, C, E, F, G, H, I, K, L refer to the same parts as in Fig. 2, Plate 52. D D. The two crura penis.

M. The urethra in section

N N. The rectum.

O. The sacro-sciatic ligament.

Plate 53.--Figure 1.

FIGURE 2.

A, B, D, G, H, I, K, L, O refer to the same parts as in Fig. 1, Plate 53. C C. The two lobes of the prostate.

F. The rectum turned down.

M. The membranous part of the urethra.

N N. The vesiculae seminales.

P. The base of the bladder.

Q Q. The two vasa deferentia.

Plate 53.--Figure 2.

COMMENTARY ON PLATES 54, 55, & 56.

THE SURGICAL DISSECTION OF THE MALE BLADDER AND URETHRA.-- LATERAL AND BILATERAL LITHOTOMY COMPARED.

Having examined the surgical relations of the bladder and adjacent structures, in reference to the lateral operation of lithotomy, it remains to reconsider these same parts as they are concerned in the bilateral operation and in catheterism.

Fig. 1, Plate 54, represents the normal relations of the more important parts concerned in lithotomy as performed at the perinaeal region. The median line, AA, drawn from the symphysis pubis above, to the point of the coccyx below, is seen to traverse vertically the centres of the urethra, the prostate, the base of the bladder, the anus, and the rectum. These several parts are situated at different depths from the perinaeal surface. The bulb of the urethra and the lower end of the bowel are on the same plane comparatively superficial. The prostate lies between these two parts, and on a plane deeper than they. The base of the bladder is still more deeply situated than the prostate; and hence it is that the end of the bowel is allowed to advance so near the pendent bulb, that those parts are in a great measure concealed by these. As the apex of the prostate lies an inch (more or less) deeper than the bulb, so the direction of the membranous urethra, which intervenes between the two, is according to the axis of the pelvic outlet; the prostatic end of the membranous urethra being deeper than the part near the bulb. The scalpel of the lithotomist, guided by the staff in this part of the urethra, is made to enter the neck of the bladder deeply in the same direction. On comparing the course of the pudic arteries with the median line, A A, we find that they are removed from it at a wider interval below than above; and also that where the vessels first enter the perinaeal space, winding around the spines of the ischia, they are much deeper in this situation (on a level with the base of the bladder) than they are when arrived opposite the bulb of the urethra. The transverse line B B, drawn in front of the anus from one tuber ischii to the other, is seen to divide the perinaeum into the anterior and posterior spaces, and to intersect at right angles the median line A A. In the same way the line B B divides transversely both pudic arteries, the front of the bowel, the base of the prostate, and the sides of the neck of the bladder. Lateral lithotomy is performed in reference to the line A A; the bilateral operation in regard to the line B B. In order to avoid the bulb and rectum at the median line, and the pudic artery at the outer side of the perinaeum, the lateral incisions are made obliquely in the direction of the lines CD. In the bilateral operation the incision necessary to avoid the bulb of the urethra in front, the rectum behind, and the pudic arteries laterally, is required to be made of a semicircular form, corresponding with the forepart of the bowel; the cornua of the incision being directed behind. In the lateral operation, the incision C through the integument, crosses at an acute angle the deeper incision D, which divides the neck of the bladder, the prostate, &c. The left lobe of the prostate is divided obliquely in the lateral operation; both lobes transversely in the bilateral.

Plate 54, Figure 1.