ABSTRACT
Objective To identify and save parathyroid glands during thyroidectomy by displaying their autofluorescence. Methods Autofluorescence imaging was carried out during thyroidectomy with and without central lymph node dissection. After visual recognition by the surgeon, the parathyroid glands and the surrounding tissue were exposed to near-infrared light with a wavelength of 690-770 nm using a modified Karl Storz near infrared/indocyanine green endoscopic system. Parathyroid tissue was expected to show near infrared autofluorescence at 820 nm, captured in the blue channel of the camera. Results We investigated 41 parathyroid glands from 20 patients; 37 glands were identified correctly based on near-infrared autofluorescence. Neither lymph nodes nor thyroid revealed substantial autofluorescence and nor did adipose tissue. Conclusions Parathyroid tissue is characterised by showing autofluorescence in the near-infrared spectrum. This effect can be used to identify and preserve parathyroid glands during thyroidectomy.
Subject(s)
Optical Imaging/methods , Parathyroid Glands/diagnostic imaging , Spectroscopy, Near-Infrared/methods , Thyroidectomy/methods , Cohort Studies , Humans , Parathyroid Glands/surgery , Thyroid Gland/diagnostic imaging , Thyroid Gland/surgeryABSTRACT
BACKGROUND: Optical coherence tomography (OCT) is a high-resolution imaging technique that allows the identification of microarchitectural features in real-time. OBJECTIVE: Can OCT be used to differentiate parathyroid tissue from other cervical tissue entities? MATERIAL AND METHODS: All investigations were carried out during cervical operations. Initially, ex vivo images were analyzed to define morphological imaging criteria for each tissue entity. These criteria were used to evaluate a first series of ex vivo images. In a second phase the practicability of the technique was investigated in vivo and in the third phase backscattering intensity measurements were analyzed employing linear discriminant analysis (LDA). RESULTS: In the ex vivo series parathyroid tissue could be differentiated from other tissue entities with a sensitivity and specificity of 84 % and 94 %, respectively. Parathyroid tissue was correctly identified in the in vivo series in only 69.2 %. The analysis of backscattering intensity profiles employing LDA reliably distinguished between the different tissue types. CONCLUSION: The OCT images displayed typical characteristics for each tissue entity. Due to technical problems in handling the probe the in vivo OCT images were of much poorer quality. Backscattering intensity measurements illustrated that OCT images provide an individual profile for each tissue entity independent of the defined morphological assessment criteria. The results show that OCT is fundamentally suitable for intraoperative differentiation of tissues.
