Hemodynamic monitoring of the contralateral testis during unilateral testicular torsion describes the mechanism of damage.

Contralateral testicular perfusion during unilateral testicular torsion was evaluated using simultaneous blood flow and O2 content determinations. Two groups, each consisting of 7 rats, were studied. Sham operation or 720 degrees clockwise twisting was performed on the left testes, and blood flow, O2 content and temperatures were monitored in the right testes for 180 min. An ultrasonic perivascular Doppler flowmeter system, an electronic thermometer and an O2 electrode were used for the monitoring. The contralateral testicular blood flow and relative O2 contents were stable in the control group. However, the initial and 180 min blood flow values decreased from 0.21 +/- 0.04 to 0.11 +/- 0.02 ml/min (p < 0.001), and the O2 contents from 0.857 +/- 0.123 to 0.319 +/- 0.037 (1.0 corresponds to 19.6 mm Hg pO2, p < 0.05) in the experimental group. Unilateral testicular torsion decreases the blood flow and O2 content of the contralateral testis. The contralateral testicular injury encountered following unilateral testicular torsion might result from hypoxia following the decrease in blood flow.