New animal model to evaluate testicular blood flow during testicular torsion.
OBJECTIVE
Unilateral testicular torsion is known to cause infertility because of damage to the contralateral testis. Testicular damage has been attributed to many different mechanisms, one of which is altered contralateral blood flow. In our experiment, in an effort to identify the reason for contralateral testicular injury, the authors developed an accurate method of measuring blood flow in both testes before, during, and after unilateral torsion.


METHODS
Four- to 6-week-old piglets weighing 4 to 6 kg were studied. The animals were anesthetized, intubated, ventilated, and catheterized for vascular access. Piglets were assigned randomly to a sham group or a group undergoing 360 degrees or 720 degrees torsion of the left testis (n = 5 per group) for 8 hours, after which it was untwisted. Data were collected at baseline (T = 0), 8 hours of torsion (T = 8), and 1 hour after detorsion (T = 9). Mean arterial blood pressure and heart rate were monitored continuously. Testicular blood flow was determined using radiolabeled microspheres. Blood flow data were evaluated by analysis of variance.


RESULTS
In the 360 degrees torsion group, blood flow changes were insignificant during torsion and after detorsion. In the 720 degrees torsion group, blood flow to the twisted testis was reduced significantly, whereas the contralateral testis was unaffected. One hour after detorsion, blood flow to both testes was increased significantly.


CONCLUSIONS
The authors describe a new animal model to evaluate testicular blood flow during and after testicular torsion. Increased blood flow after detorsion may be the cause of testicular damage in patients with unilateral testicular torsion.
Division of Pediatric Surgery, University of Illinois College of Medicine at Chicago, 60016, USA.
G
G
Lievano
L
L
Nguyen
J
J
Radhakrishnan
L
L
Fornell
E
E
John
D000818:Animals; D004195:Disease Models, Animal; D008297:Male; D008863:Microspheres; D011897:Random Allocation; D012039:Regional Blood Flow; D013086:Spermatic Cord Torsion / Q000503:physiopathology*; D013552:Swine; D013737:Testis / Q000098:blood supply*