By permanent stricture is understood a narrowing of the canal from organic change in the tissue of the urethra itself, or the corpus spongiosum. Permanent stricture may at tack any portion of the urethra ; even the prostatic part, thef5ssa navicularis, and the bulb have been tlieseat of stricture : thus, Ricord and Cross have met with stricture in the prostatic portions, and the fossa navicu Innis has been found to be the seat of the dis ease (after ulceration) ; but, although it is by no means unfrequent in the spongy portion, it is most common in the anterior part of the membranous part of the canal. This subject has been examined by various writers on urethral diseases, but the most extended re searches are those of Mr. Phillips, and I therefore append the result of his observa tions. He selected a number of cases for examination, and he found that In 9 cases the stricture was distant from the meatus - - - 1 inch.
8 „ from 1 to 2 inches.
13 If 2 to 3 11 3 to 4 98 Pf 4 to 51 40 51 to 61 10 61 to 71 This corresponds with the observations of Ducamp, who found that, in five cases out of six, strictures are found at the distance of about 5 inches from the meatus, or from 4 inches 9 lines to 5 inches 3 lines. Amussat states that the most common seat of the dis ease is the point of junction between the bulb and membranous portions.
Varieties of permanent Strictures may be spontaneous or traumatic. Traumatic strictures generally occur at the membranous portion, but they are occasionally found in the spongy part. The former result from contusions or lacerations, the latter from di vision of the canal by cutting instruments, as after the extraction of impacted calculi, or after complete division. Whatever be the cause of traumatic stricture, if stricture en sues after a wound of the urethra, a cicatrix occurs, as in other situations, and a tendinous puckering of the membrane takes place, giving rise to the most intractable form of the dis ease. If, however, the stricture results from simple contusion inflammation attacks the part and the stricture is produced as in the common class. After ulceration of the ure thra from chancre a puckering of the mem brane gives rise to stricture in its character resembling the ordinary traumatic variety.
The most simple form of permanent stric ture is where the urethra is traversed by a fold of membrane thrown across in the form of a bridle. In this case the stricture is usually in the floor of the canal. It may occur in any part, except the prostatic, but its usual seat is the commencement of the spongy portion. The diameter of the urethra is thus
only partially occluded, the shape of the stricture being somewhat crescentic. When the urethra is completely encircled, it appears as if a slender thread were tied around it, and thus an annular stricture, or bridle, is formed, the opening being usually in the middle. The efforts to micturate often push forward the strietured part, thus inducing a valvular ap pearance. Authorities vary as to the forma tion of this stricture. Some, as Ducamp and Laennec, believe it to on the organ isation of false membrane thrown out on the mucous surface. Amussat attributes it to the healing of an ulcer, but there can be little doubt that both causes may give rise to a similar condition. Arutzenius considers it due to a swelling of the mucous membrane, and consequent loosening from the subjacent tissue : thus the membrane becomes wrinkled, and a fold is formed on its surface.
Hunter attributes the origin of these stric tures to spasm of the circular muscular fibres of the urethra. Sir C. Bell describes them as occasionally splitting into branches, and running in a longitudinal rather than a circular direction. He considers them as the result of inflammation of the mucous surface : to this opinion most modern surgeons subscribe. Sometimes two or more annular or bridle strictures coexist at short intervals in the same urethra. Hunter met with six, Lallemand seven, and Calot as many as eight.
The next variety of permanent or organic stricture is that in which the urethra is nar rowed to a much greater extent of its course than in the former case. In these cases half an inch or an inch, or even the whole extent of the spongy part of the urethra, is more or less contracted. The stricture occupies one or other side, or it completely encircles the tube. It varies in consistence, from a soft, yielding thickening of the membrane, to a complete cartilaginous hardening. The dis ease in its most simple form occupies either the mucous layer alone, or the submucous I elastic layer ; but it is not limited to this, for in many cases the tissue intervening between the submucous layer and the spongy body is the seat of disease, whilst in others even the spongy body itself, whose cells are obliterated by the deposition of lymph, becomes thick ened and indurated, and thus encroaches on the urethral tube. I regard genuine simple stricture as dependent on hypertrophy of the mucous or epithelial layer and the submucous elastic lamina of the urethra.