EXPERIMENTAL DEVELOPMENT OF AN ENDOSCOPIC APPROACH TO NECK EXPLORATION AND PARATHYROIDECTOMY

Background. Recent advances in minimally invasive surgical technology have the potential to lead to new applications outside body cavities. The purpose of the present study was to develop techniques for obtaini ng endoscopic exposure and access to the pretracheal space in the neck with the goal of performing neck exploration and parathyroidectomy an d to evaluate the safety and efficacy of such an approach experimental ly. Methods. The technique for endoscopic neck exploration was develop ed in eight adult mongrel dogs and was further evaluated in a survival dog model and in human cadavers. The pretracheal space was accessed b y a 2.5 cm midline incision in the lower neck. This space was expanded with a balloon dissector, and exposure was maintained with an externa l lift device. A 5 or 10/12 mm midline Port and two to four lateral 5 mm cervical ports were placed, and dissection was carried out with ped iatric endoscopic instruments and an ultrasonic coagulator. Excised pa rathyroid tissue was verified histologically. Results. Two-gland parat hyroidectomy was successfully completed in five of six dogs; inadequat e exposure led to a failed procedure in one animal. Mean operative tim e was 130 +/- 6 minutes, and there were no operative complications. Se rum calcium levels did not change significantly after operation (p = n ot significant). At autopsy approximately 20 ml of clear sterile fluid s was present in the pretracheal space of every dog. In five human cad avers mean dissection time for attempted four-gland parathyroidectomy was 69 +/- 38 minutes (range, 45 to 135 minutes). Four of four parathy roids were identified and removed in two patients, three of three para thyroids in one patient, three of four parathyroids in one patient, an d two of four parathyroids in one patient. Conclusions. Parathyroidect omy may be Performed safely and reliably in an animal model with minim ally invasive techniques that can be applied to parathyroid dissection in human cadavers. These results suggest that an endoscopic approach to neck exploration and parathyroidectomy is potentially feasible and may warrant further study in clinical trials.