Bilateral oblique approach to parathyroid glands

Relationship between the ansa cervicalis and the omohyoid muscle: clinical consequences in parathyroid surgery

PURPOSE

To determine the position of the lower loop of the ansa cervicalis (AC) compared to the inferior edge of the omohyoid muscle to guide minimally invasive surgery for the lateral oblique approach of parathyroid glands.

METHODS

Authors performed 36 anatomical dissections in the laboratory of anatomy (Laboratoire d'Anatomie Des Alpes Françaises) of the Grenoble medical school in 2012 on human cadavers. They independently measured the distance between the caudal extremity of the AC and the lower edge of the superior belly of the omohyoid muscle. Then, they controlled this measure on pictures.

RESULTS

The study shows a majority of long AC (under the omohyoid muscle) in 66.7 % of cases. In addition, the AC was located on an average value of 0.1 cm below the lower edge of the omohyoid muscle (median -0.5 cm). Thus, two-thirds of AC are between 0 and -2 cm under the omohyoid muscle. Furthermore, the AC is generally non-symmetrical: there is a mean difference of 1.3 cm between the left and right AC. In this series, there are as many long AC on the right side as on the left side.

CONCLUSIONS

These results are in contradiction with literature data. To preserve the ansa cervicalis and its phonatory functions, it is necessary for the surgeon to perform a systematic per operative identification of the AC because the position of the AC is mainly under the omohyoid muscle and because of an asymmetry. Per operative neurostimulation and/or magnified lenses might be helpful during the surgical approach.

Selective Venous Sampling in Recurrent and Persistent Hyperparathyroidism: Indication, Technique, and Results

Between 1992 and 2002, 542 patients underwent a surgical treatment for hyperparathyroidism in our department. Twenty-three selective venous sampling procedures (SVS) were performed because of the failure of the other methods of diagnosis. These patients have recurrent or persistent hyperparathyroidism. Noninvasive methods of topographical diagnosis have failed or they have given contradictory results. In our experience, the surgeon needs a precise localization of the pathological glands in these difficult cases. In our series of SVS, specificity was 85.7% and sensitivity was 94.7%. Our results show that a high postoperative gradient of parathyroid hormone in the internal thoracic veins indicates an ectopic pathological gland in the thymus. A high gradient in a vertebral vein indicates a pathological superior parathyroid gland, usually in a retro-esophageal position.

The management of primary hyperparathyroidism

Recent improvements in parathyroid imaging have led to renewed interest in the criteria for, and the surgical approach to, parathyroidectomy. It therefore seemed appropriate to review current evidence relating to the evaluation and management of primary hyperparathyroidism for those working within a general endocrine service. The recommendations are based on an electronic search spanning the past decade using the search terms hyperparathyroidism, management and parathyroidectomy/surgery, but we have also included key publications outside this period. The findings have been graded systematically (Appendix), according to the quality of the information available, to indicate the level of evidence on which they are based.