INVESTIGATIONS ON THE PATHOGENESIS OF URETHRAL STRICTURE WITH SPECIAL REFERENCE TO PATHOLOGICAL MORPHOLOGY (COLLAGEN DISEASE?) OF THE ARTERIOLES IN PERIURETHRAL TISSUES

Abstract

A resume of investigations on urethral stricture as outlined in the reports of Rrof. Tabayashi and Midorikawa was published by our department in 1958. It was then noted that in the area of urethral stricture a definite sequence of changes was taking place in the locations neighboring the connective tissue and its arteriolar walls. The present report is concerned with the details of these changes.
Urethral stricture has hitherto been regarded as a sequela of gonorrhoeal infection, but at present there is an increasing incidence of traumatic origin, which, though somewhat differing according to geographic locations, is largely due to the rapid advances in mechanical civilization such as heavy industry, skyscraper construction and automobile manufacture. Tuberculosis also plays a role in a relatively small percentage of cases. There is also a group of urethral stricture in which the cause is unknown as judged from the past history or routine examination. A statistical summary of all cases seen in our department is herewith attempted:
Etiological incidence of urethral stricture (%) during the 10 year period
The stricture occurred at the bulba and pars membranecea urethra in 35 cases, while it involved the anterior urethra in 5 cases.
The materials for the present investigation consisted of the transverse or longitudinal serial sections prepared from 1-4.5cm circular blocks of stricture tissue obtained from these 40 patients. The sections were stained by 10 different methods, namely hamatoxylineosin, Van Gieson's stain, Weigert's method, Mallory's stain, Mallory's phosphotungstic acid-hematoxylin stain, PAS stain and others.
The general and pathological findings of the tissue may here be omitted, since they agree fairly well with the description published by Midorikawa in his on “Clinical and histopathological studies on urethral stricture” (Japan 'J. Urology, Vol 49, No. 11, 1958). Of the histological observations those presenting various changes of peripheral arterioles may be classified as follows:
This table indicates that the cases with vasculitic type are by far most numerous, followed in order by those showing hypertrophy of middle layer and sclerrotic changes, while only a few presented no systematic changes.
These changes may be summarized as follows:
1) Internal meatus. The internal meatus presented varying degrees and shapes of narrowing, such as central or marginal, oval or similunar, narrowing as well as dendritic or even obstructive in nature. Occasional thrombosis containing erythrocytes and desquamated endothelial cells.
2) Internal layer. The internal layer was seen to have undergone hypertrophy in various manners, such as fibrotic and proliferative hypertrophy, or hyaline degeneration, producing the narrowing of the internal meatus.
3) Middle layer. The middle layer exhibited pictures of degenerative changes In almost all cases, including the irregularities in the arrangement as well as swelling, dissolution and even disappearance of smooth muscles.
4) External layer. The extanal layer wes generally indistinct in appearance, although there were a few wick presented fibrotic proliferation or cicatrization.
5) Many cases showed cellular infiltrations, hypertrophied internal layer and degenerative changes in the middle layer, while inflammatory cellular infiltrations around the blood vessels were frequently encountered. Generally speaking, the infiltrative changes were most remarkable in the perivascular areas. These cells were recognaized to have migrated from the internal layer into the perivascular tissues, or from the perivascular areas into the vessel walls.
6) Elastic fibers. There were many instances of vasculitic type in which degenerative pictures consisted of semicircular remains of tissues resulting from the well demarkated partial. dissolution or disappearance of swollen, proliffiferative and internal elastic layer.
In addition to the above cases, the