Contents of the Spermatic Cord
The spermatic cord contains three main arterial vessels (testicular artery, vasal artery, and cremasteric artery), the pampiniform plexus of veins organized into distinct groups, the vas deferens, lymphatic vessels, and sensory/autonomic nerves, all enclosed within fascial layers.
Vascular Structures
Arteries
The arterial supply within the spermatic cord consists of three distinct vessels 1:
Testicular artery: The dominant vessel, with diameter ranging 0.2-1.9 mm (mean 1.0 mm). Present as a single artery in 69% of cases, two arteries in 27%, and three arteries in 4%. This artery provides the majority of testicular blood flow, with its diameter equal to or exceeding the combined diameters of the vasal and cremasteric arteries in 57.5% of cases.
Vasal (deferential) artery: Present as a single vessel in 98% of cases, with diameter ranging 0.2-1.8 mm (mean 0.6 mm). This vessel accompanies the vas deferens.
Cremasteric artery: Present as a single artery in 55%, two arteries in 31%, and three arteries in 4% of cases, with diameter ranging 0.1-1.5 mm (mean 0.5 mm).
Veins
The pampiniform plexus has a complex organization with four distinct groups 2:
- Group I veins: Form a tight plexus around the testicular artery through numerous veno-venous anastomoses
- Group II veins: Run at a distance embedded in fatty tissue without close relationship to the testicular artery, with veno-venous anastomoses between themselves
- Group III veins: Form anastomoses between Group I and Group II
- Group IV veins: Form arterio-venous anastomoses with the testicular artery
The number of medium spermatic veins is higher in the subinguinal region compared to the inguinal level 3.
Non-Vascular Structures
Vas Deferens
The vas deferens runs within the cord accompanied by its associated neurovascular bundle, enclosed within its own distinct fascial sheath (vas deferens fascia) 3.
Lymphatic Vessels
Approximately 36 lymphatic vessels per patient are present within the spermatic cord, though only a few are found in the spermatic fascia 4.
Nerves
The nerve distribution is extensive 4:
- 50% of nerves are located near the vas deferens
- 20% of nerves are found in the spermatic fascia
- Sensory nerves (CGRP-positive) and sympathetic nerves (tyrosine hydroxylase-positive) account for the majority
- Parasympathetic fibers (VIP-positive) are present but sparse
- The genital branch of the genitofemoral nerve runs within the spermatic cord in 97% of cases, typically between the cremaster fibers and internal spermatic fascia, related to inferior fibers in 59% and lateral/medial fibers in 38% 5
Fascial Organization
The spermatic cord structures are organized within two distinct fascial sheaths 3:
- Internal spermatic fascia: Encloses the internal spermatic vessels (testicular artery and pampiniform plexus)
- Vas deferens fascia: Separately encloses the vas deferens and its associated neurovascular bundle
These thin, translucent sheaths separate the two main neurovascular bundles from each other and from surrounding tissues.
Clinical Relevance
This anatomical organization is critical during surgical procedures on the spermatic cord. During inguinal orchidectomy for testicular cancer, the cord should be divided at the internal inguinal ring 6. The testicular artery's dominant caliber emphasizes the importance of its preservation during varicocelectomy to maintain optimal testicular blood flow 1.