Unilateral neck exploration for primary hyperparathyroidism: Analysis of a controversy using a mathematical model

• Published in: World journal of surgery 1992-07, Vol.16 (4), p.654-661
• Main Authors: Duh, Quan‐Yang, Udén, Per, Clark, Orlo H.
• Format: Article
• Language: English
• Subjects: Adenoma; Adenoma - complications; Adenoma - epidemiology; Adenoma - surgery; Biological and medical sciences; Endocrinopathies; Humans; Hyperparathyroidism - etiology; Hyperparathyroidism - surgery; Medical sciences; Models, Theoretical; Neck Exploration; Non tumoral diseases. Target tissue resistance. Benign neoplasms; Nous Avons; Parathyroid Gland; Parathyroid Glands - surgery; Parathyroid Neoplasms - complications; Parathyroid Neoplasms - epidemiology; Parathyroid Neoplasms - surgery; Parathyroids. Parafollicular cells. Cholecalciferol. Phosphocalcic homeostasis (diseases); Primary Hyperparathyroidism; Surgical Procedures, Operative - methods
• ISSN: 0364-2313; 1432-2323
• DOI: 10.1007/BF02067347

Most endocrine surgeons explore both sides of the neck and identify all parathyroid glands when operating on patients with primary hyperparathyroidism. Others, however, advocate the unilateral approach, i.e., if an adenoma and a normal gland are identified, the contralateral side is not explored. We analyzed the strategy of the unilateral approach using a mathematical model to determine the variables that influence the probability of missing a tumor on the unexplored side of the neck. Assuming the frequency of single adenoma is 80%, hyperplasia 14%, double adenomas 4%, triple adenomas 1%, and carcinoma 1%, and the probability of missing a tumor on the explored side is 5%, we found that: 1. Only 41% of the patients treated by the unilateral approach undergo unilateral exploration. This is increased to 62% when a localization study with a sensitivity of 80% is used pre‐operatively. 2. The probability of missing a tumor on the unexplored side of the neck parallels the prevalence of multiple adenomas. Half of the patients with triple adenomas and two‐thirds of the patients with double adenomas will have a missed tumor when treated by the unilateral approach. 3. Patients who undergo unilateral exploration have an additional 7% to 8% probability of missing a tumor that would have been found if bilateral exploration is performed. This risk is lowered to 2% by a pre‐operative localization study that is 80% sensitive. 4. A prospective study will require 684 patients, randomized to the unilateral or bilateral approach, to have an 80% statistical power (α=0.05, β=0.20) of detecting a difference between a 5% and a 10% risk of missing a tumor. Résumé La plupart des chirurgiens explorent la région cervicale de façon bilatérale et identifient toute les glandes parathyroïdes au cours de l'intervention pour hyperparathyroïdie primaire. D'autres, toutefois, plaident pour un abord unilatéral et, lorsqu'un adénome et une glande normale sont identifiés, n'explorent pas la région controlatérale. Nous avons analysé la stratégie de l'abord unilatéral à l'aide d'un modèle mathématique afin de déterminer les variables qui augmentent la probabilité de méconnaître une tumeur dans la région cervicale inexplorée. En estimant les fréquences d'adénome unique à 80%, d'hyperplasie à 14%, de double adénome à 4%, de triple adénome à 1% et de carcinome à 1% ainsi que la probabilité de méconnaître une tumeur dans la région inexplorée à 5%, nous avons trouvé que: 1) seulement 41% des patients t