Minimally invasive videoscopic parathyroidectomy by lateral approach.

METHODS: A videoscopic parathyroidectomy was performed in 22 patients presenting with primary hyperparathyroidism (PHPT). No patient had undergone previous neck surgery, presented with goiter or had a history of familial PHPT. Ultrasonography and Sestamibi scanning were performed preoperatively. Rapid intact parathormone assay was used during surgery. Through a 15-mm transversal skin incision on the anterior border of the sternocleidomastoid muscle (SCM), the fascia connecting the lateral portion of the strap muscles and the thyroid lobe with the carotid sheath was gently divided, far enough to visualize the prevertebral fascia. Once enough space was created, three trocars were inserted: a 12-mm trocar through the incision and two 2.5-mm trocars on the line of the anterior border of the SCM, above and below the first trocar. Carbon dioxide was insufflated to 8 mmHg. Unilateral video-assisted parathyroid exploration was then carried out using a 10-mm O(o) endoscope. Once the adenoma had been identified, the trocars were removed. Then, directly through the skin incision, the thyroid lobe was retracted medially and the adenoma was extracted after clipping its pedicle. Among the 23 enlarged glands, 20 (80%) were correctly identified by endoscopic exploration: mean weight 843 mg (100 mg to 5 g). The exploration was unilateral in 17 patients but bilateral in 5. Mean time of unilateral endoscopic exploration was 84 min (40-130 min). Morbidity was represented by two superficial hematomas. All 22 patients were biochemically cured, follow-up ranging from 3 months to 14 months. CONCLUSIONS: This preliminary study demonstrates that minimally invasive videoscopic parathyroidectomy by lateral approach is a feasible surgical procedure.

[Endoscopic parathyroidectomy via a lateral neck incision]. / Parathyroïdectomie vidéo-assistée par abord latéro-cervical.

A new approach to endoscopic parathyroidectomy is proposed. Via a 15 mm transverse incision on the anterior border of the sternocleidomastoid muscle (SCM), the fascia connecting the lateral portion of the strap muscles and the thyroid lobe to the carotid sheath is divided at the level of the prevertebral fascia. Once enough space has been created, three trocars are inserted: a 12 mm trocar through the incision and two 2.5 mm trocars above and below the first trocar. Carbon dioxide is insufflated at a pressure of 8 mmHg. Unilateral endoscopic parathyroid exploration is then performed with a 10 mm-0 degree endoscopic camera. Once the adenoma has been identified and, if possible the ipsilateral parathyroid gland, the 3 trocars are removed and the adenoma is extracted from the neck after clipping its pedicle directly through the 15 mm incision. Twenty patients with sporadic primary hyperparathyroidism were operated. The adenoma was localized pre-operatively in 14 patients. Intra-operative quick parathyroid hormone assay was used. Exploration was unilateral in 15 patients--Conversion to transverse cervicotomy was performed in 5 cases. In the 50 explored parathyroid areas, 34 glands (68%) were identified by video surgery: 18 of the 21 enlarged glands (86%) and 16 of the 29 normal glands (55%). Mean operating time was 88 minutes (40'-130'). Morbidity consisted of 2 superficial hematomas in the SCM. With a follow-up ranging from 6 to 15 months, all 20 patients are biochemically cured. This study demonstrates that endoscopic parathyroid exploration can be performed via a lateral incision.

[Evaluation of an immunoradiometric assay for succinylated ACTH]. / Evaluationdudosageimmunoradiométrique de l'ACTH succinylée.

A new immunoradiometric assay for succinylated ACTH using 3 monoclonal antibodies has been developed by Immunotech (I-IRMA). It was compared to a commercial immunoradiometric assay of ACTH (Nichols Institute, N-IRMA). The functional sensitivity of I-IRMA assay was estimated at 1.5 ng/L. The comparison of both methods on plasma samples withdrawn at 8 h from 47 normal subjects showed a good correlation coefficient (r = 0.83; P < 0.001). The 24-hours secretion profiles obtained by both methods were similar in 14 normal subjects. Nevertheless, the I-IRMA mean values were about 30% lower than the corresponding N-IRMA values. This difference increased to 50% when the ACTH concentrations were low, as it the case at 24 h or during the dexamethasone suppression test. During insulin hypoglycemia stimulation test, the two procedures gave similar values. Both methods applied to a pathologic population gave similar result to those obtained on normals. In 10 patients bearing corticotroph adenomas, the profiles of ACTH secretions during 24 h were similar using both methods. The I-IRMA values were lower about 30% than N-IRMA values during the base state or after the 8 mg-dexamethasone suppression test. This difference was also observed in 6 patients with corticotroph insufficiency. In conclusion, the comparison of N-IRMA and I-IRMA methods showed the validity of the new succinylated-ACTH assay which is more efficient in the lower range of ACTH concentration. This significant decrease in the sensitivity threshold may be useful in the establishment of the cure criteria in Cushing disease.

[Intraoperative parathormone assay. The value of assessment of primary hyperparathyroidism in surgery]. / Dosage peropératoire de parathormone. Intérêt dans la chirurgie de l'hyperparathyroïdie primaire.

Peroperative assay of intact parathormone has been proposed to improve the surgical results, either by confirming cure peroperatively or to indicate the need for further search in case of persistent pathological secretion. Between October 1992 and July 1994 parathormone was assay peroperatively during 136 operations for primary hyperparathyroidism in 135 patients. Seven samples were made for each patient in the operating theatre: at intubation, at skin incision (ti), at ablation of the pathological gland, then 15 (t15), 30 (t30) and 60 (t60) minutes later. All samples were assayed with the rapid technique and controlled the next day with the standard method. The correlation coefficient between the two methods was 0.97. Comparing the drop in intact parathormone levels between cured patients and those with persistent hyperparathyroidism after surgery showed statistically significant differences. We retained a dramatic drop in hormone level by 80% between t1 and t15 with persistent low levels between t15 and t30 (ratio t30 over t15 < 1) as the criteria of cure: the drop off between t1 and t15 is not sufficient to confirm cure. Peroperative assay of intact parathormone can be used to demonstrate the presence of remaining pathological parathyroid tissue, especially important in case of highly ectopic localizations. This assay technique is not particularly well adapted to routine parathyroid surgery for primary hyperthyroidism but has been reserved for cases planned for limited dissection (operations conducted under local anaesthesia and reoperations).

Serum and synovial fluid osteocalcin in rheumatic diseases.

The mechanisms involved in juxta-articular bone destruction are poorly understood. Osteocalcin or gamma-carboxyglutamic acid (GLA) protein is a small non-collagenous bone protein. It is a sensitive marker of osteoblastic bone formation. Its seric variations in the serum in such rheumatisms as rheumatoid arthritis remain unclear. Further information on local osteoblastic activity may be obtained by assaying the level of osteocalcin in the synovium. Its serum level can be evaluated by radioimmunoassay. The same method can be used in the synovial fluid. Paired serum and synovial fluid samples have been assayed from 63 patients, 33 patients with inflammatory arthritis (rheumatoid arthritis, psoriasis, chondrocalcinosis, pyogenic arthritis) and 30 patients with mechanical joint effusion (osteoarthritis, meniscal lesions). Serum levels of osteocalcin were the same in the inflammatory group (m: 8.69 +/- 0.68 ng/ml) and in the mechanical group (m: 10.2 +/- 0.67 ng/ml). In the synovial fluid, the levels of osteocalcin were significantly lower in the inflammatory group (m: 3.27 +/- 0.40 ng/ml) than in the mechanical group (m: 6.91 +/- 0.47 ng/ml). The same results were obtained with the ratio of synovial fluid osteocalcin on serum osteocalcin. There was a significant correlation between serum and synovial fluid osteocalcin and an inverse correlation between synovial fluid osteocalcin and the number of synovial fluid cells. The present study suggests that periarticular osteoblastic depression, among patients with inflammatory arthritis, is likely.