Testicular tissue oxygen pressure.

PURPOSE: We evaluate the feasibility of continuous, intratesticular tissue oxygen pressure (IT-pO2) measurement under various conditions.

MATERIALS AND

METHODS

Flexible, polarographic microcatheter systems (1.5 F) for continuous pO2 measurements have been used. The measurements were conducted on 37 adult male albino rats. The probes could be placed intratesticularly under controlled temperatures by microsurgical techniques. The IT-pO2 of the ipsilateral and contralateral testicle was determined after unilateral torsion. Furthermore the influence of intratesticular temperature on IT-pO2 was determined.

RESULTS

Intratesticular pO2 was found to be 21 +/- 5 mm.Hg under normal conditions. Under complete ischemia, pO2 dropped within 3 to 5 minutes to a level of approximately 1 mm.Hg. A counterclockwise unilateral testicular torsion of 720 degrees led to a decrease of the IT-pO2 within 5 to 7 minutes to 5 +/- 1.5 mm.Hg. After detorsion the IT-pO2 recovered within 15 minutes, while the IT-pO2 of the contralateral testicle remained unchanged. Simple surgical exposure of the testicle led to a reversible decrease of the intratesticular pO2 to 7 +/- 2.5 mm.Hg correlating with an intratesticular temperature decrease from approximately 31.5 to 23.5 C.

CONCLUSIONS

The measurements are feasible and may provide a continuous intraoperative assessment of intratesticular oxygen pressure. The contralateral IT-pO2 after unilateral torsion remained unchanged. The IT-pO2 and testicular blood flow depend, if the utilization of oxygen is unchanged, on intratesticular temperature.