Comparison between optical coherence tomographic and histopathologic appearances of artifacts caused by common surgical conditions and instrumentation

Objective: To document the appearance of artifacts created by commonly encountered surgical conditions and instrumentation on optical coherence tomography (OCT) and to compare these findings with histopathology. Study design: Ex vivo study. Animals: Five canine cadavers. Methods: Skin, subcutaneous fat, skeletal muscle, and fascia samples were obtained from fresh canine cadavers. Blood pooling, hemostatic crushing, scalpel blade cut, monopolar electrosurgery, bipolar vessel sealing device, and ultrasonic energy surgical artifacts were induced on each tissue type. Each specimen was imaged with OCT and subsequently histologically processed. Results: Most surgical instrumentation used for tumor excision created a high-scattering region with local architectural disruption. Blood pooling was visible as a high-scattering layer overlying tissue with normal architecture. Only the scalpel blade created a focal, low-scattering area representing a sharply demarcated cut within the tissue distinct from the appearance of other instrumentation. Conclusion: Common surgical instruments and conditions encountered during tumor excision produced high-scattering OCT artifacts in tissues commonly seen at surgical margins. Clinical significance: The clinical value of OCT hinges on the ability of personnel to interpret this novel imaging and recognize artifacts. Defining and describing the appearance of common surgical artifacts provides a foundation to create image libraries with known histological and OCT interpretation, ultimately improving the diagnostic accuracy of OCT for assessment of surgical margins.