Testicular tissue oxygen pressure

Purpose: We evaluate the feasibility of continuous intratesticular tissue oxygen pressure (IT-pO(2)) measurement under various conditions. Materials and Methods: Flexible, polarographic microcatheter systems (1.5 F) for continuous pO(2) 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-pO(2) of the ipsilateral and contralateral testicle was determined after unilateral torsion. Furthermore the influence of intratesticular temperature on IT-pO(2) was determined. Results: Intratesticular pO(2) was found to be 21 +/- 5 mm.Hg under normal conditions. Under complete ischemia, pO(2) 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-pO(2) within 5 to 7 minutes to 5 +/- 1.5 mm.Hg. After detorsion the IT-pO(2) recovered within 15 minutes, while the IT-pO(2) of the contralateral testicle remained unchanged. Simple surgical exposure of the testicle led to a reversible decrease of the intratesticular pO(2) to 7 +/- 2.5 mm.Hg correlating with an intratesticular temperature decrease from approximately 31.5C to 23.5C. Conclusions: The measurements are feasible and may provide a continuous intraoperative assessment of intratesticular oxygen pressure. The contralateral IT-pO(2) after unilateral torsion remained unchanged. The IT-pO(2) and testicular blood flow depend, if the utilization of oxygen is unchanged, on intratesticular temperature.