Visualization of prostatic nerves by polarization-sensitive optical coherence tomography

Abstract

Preservation of prostatic nerves is critical to recovery of a man's sexual potency after radical prostatectomy. A real-time imaging method of prostatic nerves will be helpful for nerve-sparing radical prostatectomy (NSRP). Polarization-sensitive optical coherence tomography (PS-OCT), which provides both structural and birefringent information of tissue, was applied for detection of prostatic nerves in both rat and human prostate specimens, ex vivo. PS-OCT imaging of rat prostate specimens visualized highly scattering and birefringent fibrous structures superficially, and these birefringent structures were confirmed to be nerves by histology or multiphoton microscopy (MPM). PS-OCT could easily distinguish these birefringent structures from surrounding other tissue compartments such as prostatic glands and fats. PS-OCT imaging of human prostatectomy specimens visualized two different birefringent structures, appearing fibrous and sheet-like. The fibrous ones were confirmed to be nerves by histology, and the sheet-like ones were considered to be fascias surrounding the human prostate. PS-OCT imaging of human prostatectomy specimens along the perimeter showed spatial variation in the amount of birefringent fibrous structures which was consistent with anatomy. These results demonstrate the feasibility of PS-OCT for detection of prostatic nerves, and this study will provide a basis for intraoperative use of PS-OCT. References and links1. P. C. Walsh and P. J. Donker, "Impotence following radical prostatectomy: insight into etiology and prevention," J. Urol. 128(3), 492-497 (1982). 2. F. Montorsi, A. Salonia, N. Suardi, A. Gallina, G. Zanni, A. Briganti, F. Deho', R. Naspro, E. Farina, and P.Rigatti, "Improving the preservation of the urethral sphincter and neurovascular bundles during open radical retropubic prostatectomy," Eur. Urol. 48(6), 938-945 (2005 524-535 (2015).

Polarization sensitive optical coherence tomography – a review [Invited]

“…20, demonstrating the reduced birefringence in tumor tissue. PS-OCT could also find an application in the study of the regeneration of nerves after injury or to visualize nerves intraoperatively during e.g., prostatectomy, due to the contrast PS-OCT images provide over structural intensity images for nerves due to their birefringent properties [171][172][173].…”

Polarization Sensitive Optical Coherence Tomography: A Review of Technology and Applications

“…In an experimental nerve crush model, decreasing birefringence was observed in parallel to a loss of myelination (Figure 12a-d) [225]. The prostatic nerves-indiscernible from surrounding tissue by standard, intensity based OCT-were identified in prostates of rats and humans, thereby indicating the feasibility of PS-OCT as a method for intrasurgical imaging [226].…”

Different Nerve-Sparing Techniques during Radical Prostatectomy and Their Impact on Functional Outcomes

“…The potential injury and functional recovery of the nerves depends first of all on the nature of the nerves. While some studies have failed to identify myelinated nerve fibers originating from inferior hypogastric plexus [ 33 ], others have shown both myelinated and unmyelinated components in prostatic nerves [ 34 , 35 ]. There are several classifications used for evaluating and terming nerve injuries [ 36 ].…”