Orthogonal polarization spectral imaging: a novel tool for examination of microcirculatory changes in the testis

Testicular torsion is a surgical emergency in urologic practice. Many models have demonstrated the relationship between the degree and duration of the torsion and the subsequent damages of the testis, but there are as yet no suitable methods for visualization of the testicular microcirculation in this condition. We aimed to use orthogonal polarization spectral (OPS) imaging to observe the microcirculatory changes in the testis after ischemia-reperfusion (I/R) challenge, and to compare this technique with that of fluorescence intravital video microscopy (IVM). Twelve rats subjected to 60-minute ischemia following 720° testicular torsion were divided into two groups for IVM or OPS imaging examinations of the microcirculatory network of the testis at 60, 120, 180, and 240 minutes after reestablishment of perfusion. Significant microcirculatory failure was demonstrated after I/R in both groups. The absolute values of the microcirculatory parameters recorded with the OPS and IVM imaging methods did not differ statistically. The microcirculatory disturbances are present during the later phases of testicular torsion. OPS imaging technique represents an accurate noninvasive method to detect physiologic and pathophysiologic changes in the microcirculation of the testis.