IN-SITU PRESERVATION OF THE PARATHYROID-GLANDS DURING OPERATIONS ON THE THYROID

Objective: To study the microcirculation of the parathyroids before an d after dissection during operations on the thyroid gland to see if th ere were better ways of preserving them. Design: Prospective open stud y. Setting: University hospital, Sweden. Subjects: 16 Patients undergo ing operations on the thyroid gland. 20 Parathyroid glands located ant eriorly on the thyroid lobe were selected for study. Interventions: Re cording of microcirculation of the parathyroids with laser Doppler flo wmetry. Recording of the macroscopic appearance of the parathyroid gla nds. Main outcome measures: Correlation between reduction in blood flo w and the macroscopic appearance of glands while they were ischaemic. Results: Parathyroid microcirculation before dissection gave a mean Do ppler signal level of 4.6 (1.4) V. 30 minutes after dissection to pres erve the gland the remaining mean (SD) signal was 37 (24)% of the init ial level. At the end of the operation the microcirculation tended to recover about 46 (21)% of the original value (p = 0,33). The macroscop ic appearance of the gland during the ischaemic period did not correla te well with the reduction in blood flow. Conclusion: During dissectio n to preserve normal parathyroid glands there was a discrepancy betwee n the macroscopic appearance and changes in the microcirculation. The microcirculation recovers and this can be verified by laser Doppler fl owmetry.