The spermatic cord is a cord-like structure in males that connects the abdominal cavity to the testes, via a channel known as the inguinal canal. The spermatic cord contains various structures and is surrounded by three layers of fascia.
From 12 weeks of gestation onwards, the testes descends from the abdominal cavity and into the scrotum. An invagination of the peritoneum (the processus vaginalis) is found at the lower gubernaculum, and initiates the descent of the testes. As the processus vaginalis lengthens it pulls fibres and fascia from the abdominal wall, eventually forming the internal and external spermatic fascia and cremasteric fascia of the spermatic cord.
Deep (internal) inguinal ring: 2 cm superior to the mid-point of inguinal ligament, which runs between the pubic tubercle and anterior superior iliac spine (ASIS).
Superficial (external) inguinal ring: 1 cm superior and lateral to the pubic tubercle. The spermatic cord terminates at the posteromedial border of the testes.
The structures contained within the spermatic cord are as follows:
- Arteries: Testicular, cremasteric and artery to the vas
- Veins: Pampiniform plexus, cremasteric vein and testicular vein
- Nerves: Genital branch of Genitofemoral nerve, testicular nerves (sympathetic nerves) and the ilioinguinal nerve (runs externally to the cord)
- Vas deferens
- Lymphatics (Drain into the para-aortic nodes at L1/2 level)
- Processus vaginalis (extension of the peritoneum)
The spermatic cord also contains three fascial planes:
- External spermatic fascia, originating from the external oblique muscle
- Cremasteric fascia, which runs with the cremasteric muscle), originating from the internal oblique and transversus abdominis muscles
- Internal spermatic fascia, originating from the transversalis fascia
The testicular artery originates from the aorta at the level of L2 while the corresponding testicular veins drain into the IVC on the right and the left renal vein on the left. Both the artery and vein lie retroperitoneally on the psoas major. The cremasteric vessels originate and drain into the inferior epigastric vessels. The artery of the vas originates from the inferior vesicle artery, an anterior division of the internal iliac artery.
The genital branch of Genitofemoral nerve originates from the L2 nerve root and contains both motor (to the cremasteric muscle) and sensory components (innervation to the scrotal skin, round ligament and labia majora). The sympathetic nerve fibres carry pain sensation from the viscera to T9 & 10 dermatomes.
Testicular torsion: Twisting of the spermatic cord around the axis of the testicle causes ischaemia, causing the rapid onset of testicular pain. This is commonly due to inadequate fixation of the testicle to the scrotum.
Varicocoele: This is caused by abnormally dilated veins of the pampiniform plexus usually secondary to incompetent valves. It is commonly left-sided due to the acute angle at which the testicular vein enters the left renal vein and can cause male infertility. External compression of the left renal vein can also cause the condition.
The fascial layers of the spermatic cord are formed from the abdominal wall musculature as the processus vaginalis lengthens towards the scrotum
Arteries: Testicular, cremasteric and artery to the vas
Veins: Pampiniform plexus, cremasteric vein and testicular vein
Genital branch of Genitofemoral nerve, testicular nerves (sympathetic nerves) and the ilioinguinal nerve (runs externally to the cord)
Para-aortic nodes at L1/2 level
The ‘rule of 3’s’ can be useful in order to remember the contents of the spermatic cord: three fascial coverings, three arteries, three veins, three nerves and others (lymphatics, processus vaginalis and vas deferens). It is important to note that one of the nerves (ilioinguinal) runs externally to the spermatic cord.
The spermatic cord is a complex anatomical structure that contains vessels, nerves and other structures. The tunica vaginalis is an extension of the peritoneum, which forms the serosal covering of cord, and is a reminder of the embryological origin of the cord from the abdominal cavity.
Drake, Richard L et al. Gray's Anatomy For Students. Philadelphia: Elsevier/Churchill Livingstone, 2005, p260-2
Shadbolt CL, Heinze SB, Dietrich RB. Imaging of groin masses: inguinal anatomy and pathologic conditions revisited. Radiographics. 2001;21 Spec No: S261-71.
Sadler, T. W, and Jan Langman. Langman's Medical Embryology. Philadelphia: Lippincott William & Wilkins, 2010, p253-5.