This section is from the book "Applied Anatomy: The Construction Of The Human Body", by Gwilym G. Davis. Also available from Amazon: Applied anatomy: The construction of the human body.
The penis is frequently amputated for carcinoma, which disease is favored in the aged by the irritation resulting from a long-existing phimosis. In operating two things are to be guarded against, bleeding and subsequent contraction of the meatus. Bleeding may come from the dorsal arteries or the artery which runs in the middle of each corpus cavernosum. They can first be controlled by a circular rubber band and then later readily ligated. To prevent contraction of the new meatus three methods are available: (1) A long dorsal and short under flap may be cut and the urethra dissected out from the under flap and allowed to project beyond the cut corpora cavernosa. The long dorsal flap is brought down, pierced, and the urethra drawn through. It is then slit up and sewed on each side. A few sutures are then used to unite the upper and lower flaps below the urethra. (2) Two lateral flaps may be made and the split urethra sewed in the line of union between the two flaps. (3) (Writer's, University Medical Magazine, January, 1897.) A circular cut is made around the penis and the skin turned back. The penis is then turned up, the urethra dissected out for 1.25 cm. (1/2 in.), and the corpora cavernosa divided. The arteries being tied, the two outer edges of the corpora cavernosa are brought together in the median line with three catgut sutures. The urethra is then slit up in three places, one below and two above; the three square flaps so formed are then turned back and their corners cut off. This makes three small triangular flaps which when spread out form one large triangle. The skin is then sutured accurately to the edges of this triangle and no raw surface is left (Fig. 471).
Fig. 470. - Circumcision.
The scrotum is the bag in which the testicles are contained. It consists of skin and dartos. The remaining tissues covering the testicles are derived from the layers of the abdominal wall and belong properly to them. The skin is thin, loose, wrinkled, and contains sebaceous glands which frequently become occluded, forming small tense cystic tumors. The dartos is composed of loose connective tissue and unstriped muscular fibres. It is intimately connected with the skin but moves freely on the parts beneath. It is continuous with the general superficial fascia and with its deep layer or Scarpa's fascia of the abdomen and Colles's fascia of the perineum. It dips between the testicles, forming an incomplete septum (Fig. 472).
Contraction of the dartos wrinkles the scrotum and if wounded the edges are inverted. For this reason, in operations on the scrotum, if primary union is desired particular care must be taken to approximate accurately the skin edges and prevent their inversion. The raising of the testicles is done by the cremaster muscle and not by the dartos except incidentally as the scrotum contracts. The scrotum is supplied by blood through the perineal branches of the internal pudic artery, and by the external pudic. On account of the looseness of the skin attachment, oedema and extravasation of blood and urine may be very extensive and violent. They readily impair the blood circulation and gangrene not infrequently results. It is for this reason that urinary infiltrations are to be at once incised, and in operations the greatest care is exercised to stop every bleeding vessel. Infection of this region is particularly troublesome and a strict technic is necessary in operating to avoid it. In some cases of varicocele with pendulous scrotum a portion of the scrotum is excised in order to support the testicles.
Fig. 471. - Amputation of the penis. Mucous membrane of urethra everted, cut in triangular form and sewed to the skin to avoid cicatrical contraction. (Author's method).
Fig. 472. - Scrotum, testicles, and spermatic cord.