THE VARIOUS FORMS AND POSITIONS OF STRICTURES AND OTHER OBSTRUCTIONS OF THE URETHRA.—FALSE PASSAGES.—ENLARGEMENTS AND DEFORMITIES OF THE PROSTATE.
Impediments to the passage of the urine through the urethra may arise from different causes, such as the impaction of a small calculus in the canal, or any morbid growth (a polypus, &c.) being situated therein, or from an abscess which, though forming externally to the urethra, may press upon this tube so as either to obstruct it partially, by bending one of its sides towards the other, or completely, by surrounding the canal on all sides. These causes of obstruction may happen in any part of the urethra, but there are two others (the prostatic and the spasmodic) which are, owing to anatomical circumstances, necessarily confined to the posterior two-thirds of the urethra. The portion of the urethra surrounded by the prostate can alone be obstructed by this body when it has become irregularly enlarged, while the spasmodic stricture can only happen to the membranous portion of the urethra, and to an inch or two of the canal anterior to the bulb, these being the parts which are embraced by muscular structures. The urethra itself not being muscular, cannot give rise to the spasmodic form of stricture. But that kind of obstruction which is common to all parts of the urethra, and which is dependent, as well upon the structures of which the canal is uniformly composed, as upon the circumstance that inflammation may attack these in any situation and produce the same effect, is the permanent or organic stricture. Of this disease the forms are as various as the situations are, for as certainly as it may reasonably be supposed that the plastic lymph, effused in an inflamed state of the urethra from any cause, does not give rise to stricture of any special or particular form, exclusive of all others; so as certainly may it be inferred that, in a structurally uniform canal, inflammation points to no one particular place of it, whereat by preference to establish the organic stricture. The membranous part of the canal is, however, mentioned as being the situation most prone to the disease; but I have little doubt, nevertheless, that owing to general rules of this kind being taken for granted, upon imposing authority, many more serious evils (false passages, &c.) have been effected by catheterism than existed previous to the performance of this operation.[Footnote]
[Footnote: Home describes “a natural constriction of the urethra, directly behind the bulb, which is probably formed with a power of contraction to prevent,” &c. This is the part which he says is “most liable to the disease of stricture.” (Strictures of the Urethra.) Now, if anyone, even among the acute observing microscopists, can discern the structure to which Home alludes, he will certainly prove this anatomist to be a marked exception amongst those who, for the enforcement of any doctrine, can see any thing or phenomenon they wish to see. And, if Hunter were as the mirror from which Home’s mind was reflected, then the observation must be imputed to the Great Original. Upon the question, however, as to which is the most frequent seat of stricture, I find that both these anatomists do not agree, Hunter stating that its usual seat is just in front of the bulb, while Home regrets, as it were, to be obliged to differ from “his immortal friend,” and avers its seat to be an infinitesimal degree behind the bulb. Sir A. Cooper again, though arguing that the most usual situation of stricture is that mentioned by Hunter, names, as next in order of frequency, strictures of the membranous and prostatic parts of the urethra. Does it not appear strange now, how questions of this import should have occupied so much of the serious attention of our great predecessors, and of those, too, who at the present time form the vanguard of the ranks of science? Upon what circumstance, either anatomical or pathological, can one part of the urethra be more liable to the organic stricture than another?]
Figs. 1 and 2, Plate 59.—In these figures are presented seven forms of organic stricture occurring, in different parts of the urethra. In a, Fig. 1, the mucous membrane is thrown into a sharp circular fold, in the centre of which the canal, appears much contracted; a section of this stricture appears in b, Fig. 2. In b, Fig. 1, the canal is contracted laterally by a prominent fold of the mucous membrane at the opposite side. In c, Fig. 1, an organized band of lymph is stretched across the canal; this stricture is seen in section in c, Fig. 2. In e, Fig. 1, a stellate band of organized lymph, attached by pedicles to three sides of the urethra, divides the canal into three passages. In d, Fig. 1, the canal is seen to be much contracted towards the left side by a crescentic fold of the lining membrane projecting from the right. In f, the canal appears contracted by a circular membrane, perforated in the centre; a section of which is seen at a, Fig. 2. The form of the organic stricture varies therefore according to the three following circumstances:—1st. When lymph becomes effused within the canal upon the surface of the lining mucous membrane, and contracts adhesions across the canal. 2ndly. When lymph is effused external to the lining membrane, and projects this inwards, thereby narrowing the diameter of the canal. 3rdly. When the outer and inner walls of a part of the urethra are involved in the effused organizable matter, and on contracting towards each other, encroach at the same time upon the area of the canal. This latter state presents the form, which is known as the old callous tough stricture, extending in many instances for an inch or more along the canal. In cases where the urethra becomes obstructed by tough bands of substance, c e, which cross the canal directly, the points of flexible catheters, especially if these be of slender shape, are apt to be bent upon the resisting part, and on pressure being continued, the operator may be led to suppose that the instrument traverses the stricture, while it is most probably perforating the wall of the urethra. But in those cases where the diameter of the canal is circularly contracted, the stricture generally presents a conical depression in front, which, receiving the point of the instrument, allows this to enter the central passage unerringly. A stricture formed by a crescentic septum, such as is seen in b d, Fig. 1, offers a more effectual obstacle to the passage of a catheter than the circular septum like a f.
Plate 59. Figure 1
Plate 59. Figure 2
Fig. 3, Plate 59.—In this there are seen three separate strictures, a, b, c, situated in the urethra, anterior to the bulb. In some cases there are many more strictures (even to the number of six or seven) situated in various parts of the urethra; and it is observed that when one stricture exists, other slight tightnesses in different parts of the canal frequently attend it. (Hunter.) When several strictures occur in various parts of the urethra, they may occasion as much difficulty in passing an instrument as if the whole canal between the extreme constrictions were uniformly narrowed.
