360 SURGICAL APPLIED ANATOMY. [Chap. xvm. 



The prostatic abscess usually bursts into the 

 urethra, that being the direction in which least re- 

 sistance is encountered. If it does not enter the 

 urethra, it will probably open into the rectum, there 

 being only one layer of the pelvic fascia, and that layer 

 not a thick one, between the two organs. Indeed, the 

 posterior part of the prostatic capsule, and the anterior 

 part of the sheath of the rectum, are continuous. 

 Failing these two points of exit, the abscess may 

 progress towards the perineum. This course, however, 

 is not very usual, the advance of the abscess being 

 resisted by the dense posterior layer of the triangular 

 ligament, with the lower edge of which the prostatic 

 capsule is continuous. If the abscess reaches the 

 perineum, it will do so by running along the side 

 of the rectum. The abscess cannot make its way into 

 the pelvic cavity, its movement in that direction being 

 resisted by the pubo-prostatic ligaments which form 

 one of the very densest portions of the pelvic fascia. 

 This encasement of the gland in an unyielding mem- 

 brane will serve to in part explain the severe pain felt 

 in acute prostatic abscess. 



Hypertrophy of the prostate. The average 

 measurements of the normal prostate are an inch 

 and a half across at its widest part, and an inch and 

 a quarter from before backwards, or from apex to 

 base. After the age of fifty-three the organ is very 

 apt to become hypertrophied ; and, according to Sir 

 Henry Thompson, this hypertrophy may be considered 

 to exist when the gland measures two inches from 

 side to side, or when it weighs one ounce. The usual 

 weight of the prostate is six drachms. If the enlarge- 

 ment mainly affect the lateral lobes, it will be imder- 

 stood that the hypertrophy may attain considerable 

 dimensions without retention of urine being produced. 

 On the other hand, a comparatively trifling enlarge- 

 ment of the middle lobe may almost entirely block 



