Plate 54, Figure 2.
Fig. 1, Plate 55.—When the pudic artery crosses in contact with the prostate, F, it must inevitably be divided in either mode of operation. Judging from the shape of the prostate, I am of opinion that this part, whether incised transversely in the line B B, or laterally in the line D, will exhibit a wound in the neck of the bladder of equal dimensions. When the calculus is large, it is recommended to divide the neck of the bladder by an incision, combined of the transverse and the lateral. The advantages gained by such a combination are, that while the surface of the section made in the line D is increased by “notching” the right lobe of the prostate in the direction of the line B, the sides of both sections are thereby rendered more readily separable, so as to suit with the rounded form of the calculus to be extracted. These remarks are equally applicable as to the mode in which the superficial perinaeal incision should be made under the like necessity. If the prostate be wholly divided in either line of section, the pelvic fascia adhering to the base of this body will be equally subject to danger. By incising the prostate transversely, B B, the seminal ducts, G H, which enter the base of this body, are likewise divided; but by the simple lateral incision D being made through the forepart of the left lobe, F, these ducts will escape injury. [Footnote] On the whole, therefore, the lateral operation appears preferable to the bilateral one.
[Footnote: As to the mode in which the superficial and deep incisions in lateral lithotomy should be made, a very eminent operating surgeon remarks—“a free incision of the skin I consider a most important feature in the operation; but beyond this the application of the knife should, in my opinion, be extremely limited. In so far as I can perceive, there should be no hesitation in cutting any part of the gland which seems to offer resistance, with the exception, perhaps, of its under surface, where the position of the seminal ducts, and other circumstances, should deter the surgeon from using a cutting instrument.”—Wm. Fergusson, Practical Surgery, 3d Am. Ed., p. 610.]
Plate 55—Figure 1.
Fig. 2, Plate 55.—The muscular structures surrounding the membranous urethra and the neck of the bladder, and which are divided in lithotomy, have been examined from time to time by anatomists with more than ordinary painstaking, owing to the circumstance that they are found occasionally to offer, by spasmodic contraction, an obstacle to the passage of the catheter along the urethral canal. These muscles do not appear to exist in all subjects alike. In some, they are altogether wanting; in others, a few of them only appear; in others, they seem to be not naturally separable from the larger muscles which are always present. Hence it is that the opinions of anatomists respecting their form, character, and even their actual existence, are so conflicting, not only against each other, but against nature. In Fig. 2, Plate 55, I have summed together all the facts recorded concerning them, [Footnote] and on comparing these facts with what I have myself observed, the muscles seem to me to assume originally the form and relative position of the parts B C D E F viewed in their totality. Each of these parts of muscular structure arises from the ischio-pubic ramus, and is inserted at the median line A A. They appear to me, therefore, to be muscles of the same category, which, if all were present, would assume the serial order of B C D E F. When one or more of them are omitted from the series, there occurs anatomical variety, which of course occasions variety in opinion, fruitless though never ending. By that interpretation of the parts which I here venture to offer, and to which I am guided by considerations of a higher law of formation, I encompass and bind together, as with a belt, all the dismembered parts of variety, and of these I construct a uniform whole. Forms become, when not viewed under comparison, as meaningless hieroglyphics, as the algebraic symbols a + c - d = 11 are when the mind is devoid of the power of calculation.
[Footnote: The part C is that alone described by Santorini, who named it “elevator urethrae,” as passing beneath the urethra. The part B is that first observed and described by Mr. Guthrie as passing above the urethra. The part F represents the well-known “transversalis perinaei,” between which and the part C there occasionally appears the part E, supposed to be the “transversalis alter” of Albinus, and also the part D, which is the “ischio bulbosus” of Cruveilhier. It is possible that I may not have given one or other of these parts its proper name, but this will not affect their anatomy.]
Plate 55—Figure 2