Genitofemoral nerve
1.
Plexus
2.
Root value & type
3.
Relation
4.
Branches
5.
Distribution
6.
Function
7.
Nerve block
8.
Clinical importance
1.
Plexus : It is arises from lumbar plexus
2.
Root value : ventral divisions fo L1 and 2
3.
Type : mixed nerve ( both motor and sensory )
4.
Branches : The nerve divides
into two branches, the genital branch and the lumboinguinal
nerve also known as the femoral branch,
5.
Relation : It passes downwards,
pierces the psoas major and emerges from
its anterior surface. Genital and femoral branch of genitofemoral nerve then
continue downwards and medially to the inguinal and femoral canal respectively.
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6. Distribution
:
Distribution of Genital branch of
genitofemoral nerve:
The genital branch
passes through the deep inguinal ring and enters the inguinal
canal.
In male, the genital
branch supplies the cremaster and scrotal skin.
In female , the genital
branch accompanies the round ligament of uterus, terminating in and
innervating the skin of the mons pubis and labia majora
Distribution of femoral branch of genitofemoral nerve :
The femoral branch passes underneath the inguinal ligament, travelling through the lateral muscular compartment of
the femoral canal where it
innervates skin of the upper leg. Passing through the cribriform
fascia of the saphenous opening of the fascia lata of the thigh, it then supplies
the skin of the upper, anterior and medial side of thigh
7.
Variation
: In this
study of 200 bodies (400 nerves), 80.2% presented as a single trunk and 19.75%
as two rami: genital and femoral. The trunk or rami were usually formed by
nerve fibers from L1, L2 from the lumbar plexus. The level of emergence of the
nerve or nerves from the psoas major muscle and the level of division into
terminal branches were individually highly variable. These characteristics were
unrelated to each other, sex, age, height or weight or side of the body. The
genitofemoral nerve was present in all cases. Two types were recognized. In
type I, the trunk of the nerve divided into two main rami: genital and femoral.
In type II, the rami arose separately from the lumbar plexus. Type I was
present bilaterally in 70.5%, and type II in 10% of cases.
Spinal nerve L1, was present in nearly all cases, and L2 in all cases
sent fibers to the genitofemoral nerve. Fibers from L3 were present in only
0.75% of cases.
8.
Function
: femoral branch give sensory supply at the anteromedial aspect of thigh over
the femoral triangle
9.
Genital
branches gibe sensory supply tunica vaginalis, spermatic fasciae, small area of
anterior scrotal skin and in female round ligament of uterus , skin of mons
pubis and labium majus
10.
Nerve block
: genitofemoral nerve lies immediately lateral to the
spermatic cord as it emerges from the superficial Inguinal ring . The
spermatic cord Is identified immediately lateral to the pubic tubercle.
The area
for injection, including the scrotum, Is sterilised.
The
spermatic cord is then stabilised and medlallsed using the nondominant hand,
and 5ml of 1% lldocaine Is injected subdermally, Immediately lateral to the
cord, superficial to the bone.
Negative aspiration prior to injection
ensures non-penetrance of the peritoneum or femoral vessels.
Clinical Significance
The genitofemoral nerve can be injured during surgery in
several ways:
- It
can be lacerated during injury to the groin. This can occur with
penetrating trauma, a knife wound or surgical exploration of the
groin. In some cases, during surgery on the saphenous vein for
varicose vein ligation, retractors can cause abrasive injury.
- The genitofemoral nerve
can also be injured in the inguinal canal, usually during
inguinal hernia repair. In most cases, the injury is unnoticed during
surgery and diagnosed in the post operative period when the
patient complains of pain.
- Lifting
heavy objects can also cause injury to the genitofemoral nerve.
- When
there is spinal stenosis of the L1 or L2 segments, compression fracture or
metastatic lesions to the lumbar spine the nerve roots which give rise to
the genitofemoral nerve can be injured.
- Psoas
abscess which may occur after an open pelvic fracture or a retroperitoneal
hematoma is also known to cause irritation of
the genitofemoral nerve.
- Genitofemoral neuralgia is a relatively common pain
syndrome observed in both males and females. The patient typically
presents with unilateral pain in the lower abdomen. Rarely the pain may be
bilateral. The pain is sometimes referred to the groin area (because of
the path of the genital nerve) and the upper medial thigh (because of the
femoral branch). The pain varies in intensity from moderate to severe and
is worsened by movements that cause extension of the lower back. In most
patients, palpation of the lower abdomen in the inguinal region can
reproduce the pain. In most cases, the cause is compression of the nerve
in the inguinal canal, usually after open hernia surgery. The diagnosis is
often difficult in patients who have not had surgery.
