Intraoperative assessment of microsurgery with three-dimensional optical coherence tomography

PURPOSE: To evaluate three-dimensional optical coherence tomography (OCT) for use in the assessment of the microsurgical anastomoses of vessels and nerves. MATERIALS AND METHODS: OCT is an optical analogue of ultrasonography and is capable of imaging nontransparent biologic tissue by detecting backscattered infrared light. Cross-sectional in vitro images of rabbit and human vessels and nerves were obtained in as little as 125 msec at 10-mu m resolution by using a solid-state laser as a light source. A surgical microscope was integrated with OCT to perform simultaneous imaging with en face visualization. Cross-sectional images were assembled to produce three-dimensional reconstructions of microsurgical specimens. RESULTS: Three-dimensional OCT reconstructions depicted the structure within an arterial anastomosis and helped identify sites of luminal obstruction. The longitudinal spatial orientation of individual nerve fascicles was tracked in three dimensions to identify changes in position. In vitro human arteries and nerves embedded in highly scattering tissue and not visible at microscopy were located and imaged with OCT at eight frames per second. CONCLUSION: The three-dimensional, micrometer-scale, diagnostic imaging capabilities of OCT permit rapid feedback for assessment of microsurgical procedures. OCT technology can be readily integrated with surgical microscopes and has potential for intraoperative monitoring to improve patient outcome.