Anatomy: Groin and Inguinal
Groin
Vasculature
- Posterior to fascia lata
- Superficial vessels
- Supply the skin and subcutaneous tissue
- Branches of the femoral artery (3)
- Superficial circumflex iliac artery
- Smallest of the branches
- Pierces through the fascia lata
- Origin is usually lateral to the saphenous opening
- Travels superolaterally, in the direction of the anterior superior iliac spine
- Supplies
- Region of the skin over the lateral third of the inguinal ligament and the iliac crest
- Superficial fascia and superficial inguinal nodes along its course
- Anastomoses with branches of the deep circumflex iliac, superior gluteal, and lateral circumflex femoral artery
- Superficial epigastric artery
- Medial to the superficial circumflex iliac artery
- Following a more vertical course; ascends anterior to the inguinal ligament up to the region just below the umbilicus
- Typically originates from the anterior aspect of the femoral artery about 2–5 cm distal to the inguinal ligament
- Often originates from a trunk that is shared with the superficial circumflex iliac artery
- Supplies the skin, superficial fascia, and inguinal nodes in midinguinal area
- Branches anastomose with those of the contralateral artery and with the inferior epigastric artery
- Superficial external pudendal artery
- Medial origin on the femoral artery
- Rarely it may originate from the profunda femoris artery
- Medial route, coursing in the direction of the pubic symphysis where it traverses the spermatic cord in males and the round ligament in females
- Supplies cutaneous blood flow to the inferior abdomen, the penis, and the scrotum in males and the labia majora in females
- Anastomoses with branches of the internal pudendal artery
- Medial origin on the femoral artery
- Superficial circumflex iliac artery
- Anastomoses exist between the superficial and deep vessels
- Deep vessels
- Supplies the muscles and fascia
- Deep circumflex iliac
- Branches off of the lateral aspect of the external iliac artery
- Supplies the deep lateral groin
- Inferior epigastric
- Branch of the external iliac artery
- Origin just medial to that of the deep circumflex iliac artery
- Gives off two branches: the pubic and the external spermatic (or cremasteric)
- Forms the lateral border of the inguinal (Hesselbach’s) triangle
Inguinal Lymph Nodes
- Classified as superficial vs. deep inguinal nodes
- Fascia lata of the thigh separates the superficial and deep inguinal nodes
- Superficial inguinal nodes
- Located deep to Camper’s fascia (also referred to as the superficial fascia) and superficial to the fascia lata (or deep fascia)
- Arranged parallel to the inguinal ligament
- Anatomic groups (5):
- Central nodes around the saphenofemoral junction
- Superolateral nodes around the superficial circumflex vein
- Inferolateral nodes around the lateral femoral cutaneous and superficial circumflex veins
- Superomedial nodes around the superficial external pudendal and superficial epigastric veins
- Drain the prepuce of the penis and the scrotum
- Inferomedial nodes around the greater saphenous vein
- Deep inguinal nodes
- Lies deep to the fascia lata
- Arranged parallel and primarily medial to the femoral vein in the femoral canal
- Tend to be in close association with the femoral vein
- Cluster of one to three lymph nodes
- Fewer in number, compared to superficial inguinal nodes
- Most cephalad of the deep inguinal nodes is the Node of Cloquet
- Node of Cloquet is
- Almost always present
- Located in the femoral canal between the femoral vein and the lacunar ligament
- Lacunar ligament connects the inguinal ligament to the pectineal ligament
- Node of Cloquet is
- Receives drainage from
- Superficial group of lymph nodes
- Deep lymphatics that run with the femoral artery
- Glans of the penis and clitoris.
Femoral Triangle
Borders
- Roof: fascia lata (covers femoral sheath)
- Fascia lata is continuous with external oblique aponeurosis superiorly[1]
- Within the femoral sheath are the femoral artery and vein and the node of cloquet
- Fascia lata is continuous with external oblique aponeurosis superiorly[1]
- Floor: pectineus, ilacus, psoas major, adductor magnus muscles
- Superior: inguinal ligament (runs from anterior superior iliac spine to pubic tubercle)
- Inguinal ligament is the portion of the external oblique aponeurosis which extends between the anterior superior iliac spine and the pubic tubercle as a thick band, folded inward[2]
- Lateral: medial border of sartorius muscle
- Medial: lateral border of adductor longus muscle
- Apex: formed by the intersection of the medial border of the sartorius muscle and the lateral boarder of the adductor longus muscle
Contents
Lateral to medial: NAVEL
- Nerve
- Artery
- Vein
- Empty space
- Allows the veins and lymph vessels to distend to accommodate different levels of flow
- Lymph nodes
- Femoral Sheath
- A distal prolongation of extraperitoneal fascia that encloses the vascular compartment
- Femoral vessels and lymphatics are enclosed by the femoral sheath[3].
- Femoral nerve is located outside the femoral sheath
Nerves
- Femoral nerve
- Contains fibers originating from the L2–L4 spinal nerve roots
- Lies deep to the iliacus fascia
- Lateral to common femoral artery
- May at times be found between the artery and the vein
- Functions
- Motor: innervates the flexors of the hip and the extensors of the knee
- Pectineus, quadriceps femoris, and sartorius muscles
- Sensory: anterior thigh, anteromedial knee, medial leg, and medial foot
- Motor: innervates the flexors of the hip and the extensors of the knee
- Should be preserved during inguinal dissection.
- Some of the sensory branches, however, are commonly sacrificed in the regional node dissection.
Vasculature
- Posterior to fascia lata
- Common femoral artery
- Continuation of external iliac artery
- External iliac artery above inguinal ligament, common femoral artery below inguinal ligament
- Gives off a branch called deep (profunda) femoral artery and continues as superficial femoral artery[4]
- Blood supply to the skin of the inguinal region is from branches of the common femoral artery.
- Complete inguinal dissection necessitates ligation of these branches.
- Viability of the skin flaps raised during the dissection depends on anastomotic vessels in the superficial fatty layer of the Camper fascia
- A transverse skin incision least compromises blood supply to the skin.
- Complete inguinal dissection necessitates ligation of these branches.
- Medial to femoral nerve
- Just medial to the midpoint of the inguinal ligament in the inguinal crease region[5]
- Continuation of external iliac artery
- Common femoral vein
- Deep femoral vein and Great saphenous vein (also known as long saphenous vein) empty into the common femoral vein
- Great saphenous vein approaches common femoral vein medially
- Deep femoral vein approaches common femoral vein laterally
- Medial to common femoral artery
- Deep femoral vein and Great saphenous vein (also known as long saphenous vein) empty into the common femoral vein
References
- Delman, Keith A., and Viraj A. Master. Malignancies of the Groin. Springer International Publishing, 2018.