Page 137 - Clinical Anatomy

ECA2 7/18/06 6:43 PM Page 122

122 The abdomen and pelvis

processus vaginalis. The testis slides into the scrotum posterior to this, pro-
jects into it and is therefore clothed front and sides with peritoneum. About
the time of birth this processus obliterates, leaving the testis covered by the
tunica vaginalis. Very rarely, fragments of adjacent developing organs —
spleen or suprarenal — are caught up and carried into the scrotum along
with the testis.

Clinical features

1◊◊The testis arises at the level of the mesonephros at the level of L2/3
vertebrae and drags its vascular, lymphatic and nerve supply from this
region. Pain from the kidney is often referred to the scrotum and, con-
versely, testicular pain may radiate to the loin.
2◊◊When searching for secondary lymphatic spread from a neoplasm of the
testis, the upper abdomen must be palpated carefully for enlarged para-
aortic nodes; because of cross-communications, these may be present on
either side. Mediastinal and cervical nodes may also become involved. It is
the beginner’s mistake to feel for nodes in the groin; these are only involved
if the tumour has ulcerated the scrotal skin and hence invaded scrotal
lymphatics which drain to the inguinal nodes.
3◊◊Rarely, a rapidly developing varicocele (dilatation of the pampiniform
plexus of veins) is said to be a presenting sign of a tumour of the left kidney
which, by invading the renal vein, blocks the drainage of the left testicular
vein. Most examples of varicocele are idiopathic; why the vast majority are
on the left side is unknown, but theories are that the left testicular vein is
compressed by a loaded sigmoid colon, obstructed by angulation at its
entry into the renal vein or even that it is put into spasm by adrenalin-rich
blood entering the renal vein from the suprarenal vein!
4◊◊The testis may fail to descend and may rest anywhere along its course—
intra-abdominally, within the inguinal canal, at the external ring or high
in the scrotum. Failure to descend must be carefully distinguished from
retraction of the testis; it is common in children for contraction of the cre-
master muscle to draw the testis up into the superficial inguinal pouch—a
potential space deep to the superficial fascia over the external ring. Gentle
pressure from above, or the relaxing effect of a hot bath, coaxes the testis
back into the scrotum in such cases.
Occasionally the testis descends, but into an unusual (ectopic) position;
most commonly the testis pass laterally after leaving the external ring to lie
superficial to the inguinal ligament, but it may be found in front of the
pubis, in the perineum or in the upper thigh. In these cases (unlike the
undescended testis), the cord is long and replacement into the scrotum
without tension presents no surgical difficulty.
5◊◊Abnormalities of the obliteration of the processus vaginalis lead to a
number of extremely common surgical conditions of which the indirect
inguinal hernia is the most important.
This variety of hernia may be present at birth or develop in later life; in
the latter circumstances it is probable that the processus vaginalis has per-