The Cytoscan model E-II in intraoperative parathyroid gland identification in a rabbit model.

BACKGROUND: Intraoperative parathyroid gland identification and preservation is often a challenge even in the hands of experienced surgeons as they could be indistinguishable from fat or thyroid tissue. OBJECTIVE: The goal of this study was to demonstrate the use of the Cytoscan Model E-II, which uses orthogonal polarization spectral (OPS) imaging technology, as an intravital microscope in identifying parathyroid glands intraoperatively and differentiating the parathyroid glands from fat and thyroid tissue in a rabbit model. METHODS: The necks of 4 New England white rabbits were explored with the animals under a general anesthesia. The Cytoscan was used to obtain images of the vasculature of tissue suspected to be parathyroid, fat, and thyroid tissue. These were confirmed by histologic evaluation. RESULTS: All tissues were correctly identified by the Cytoscan and confirmed by histologic analysis. There was an obvious difference in the images obtained of fatty tissue as compared with parathyroid tissues. There was also an appreciable difference between parathyroid and thyroid tissue based on the difference in vascularity. CONCLUSIONS: OPS imaging technology can be used in identifying parathyroid glands based on the difference in vascularity from fat and the pattern and density of vessels when compared with thyroid tissue in a rabbit model. SIGNIFICANCE: The Cytoscan may play a future role in real time intraoperative identification of human parathyroid glands. Future investigation is warranted.

Cutaneous lesions in swine after decompression: histopathology and ultrastructure.

A detailed histopathologic description of skin lesions from a porcine model of decompression sickness (DCS) is presented. Pigs were dived in a dry chamber on a variety of profiles over an 11-mo period, with a 0.1-0.6 (10-60%) incidence of cutaneous lesions. The clinical appearance of the lesions evolved from irregular, sharply demarcated areas of erythema to violaceous and, eventually, darkly mottled macules. The lesions were biopsied under deep, sedative anesthesia. Histologic abnormalities were found in 91% (20/22) of the biopsies from clinically apparent cutaneous lesions. Vascular congestion was the most common finding. Focal areas of vasculitis were noted in 45% (10/22) of the lesions. Perivascular neutrophil infiltrates, edema, and occasionally, hemorrhage were also noted. Ultrastructural abnormalities were found in all of the lesions studied. Acute inflammation affecting the dermal vasculature was the most common finding. Platelets were rarely observed aggregating within vessels. The clinical and histologic features of cutaneous lesions in pigs after decompression are compared with previous accounts in humans. The model provides a useful tool for the study of cutaneous lesions in DCS and may be a means of exploring interventions in the disease.