Читать книгу Pearls and Pitfalls in Head and Neck Surgery - Группа авторов - Страница 11
ОглавлениеThyroid and Parathyroid Glands
Cernea CR, Dias FL, Fliss D, Lima RA, Myers EN, Wei WI (eds): Pearls and Pitfalls in Head and Neck Surgery. Basel, Karger, 2012, pp 10–11
DOI: 10.1159/000337465
Eveline Slotema Jean François Henry
Department of Endocrine Surgery, University Hospital Marseille, Marseille, France
P E A R L S
• Minimizing the need for reoperative surgery is the most effective way to decrease operative risks.
• Consider each parathyroid gland (PT) as if it were the last one left, even in unilateral resection.
P I T F A L L S
• Avoid reoperations in previously dissected planes by neither performing subtotal lobectomies nor enucleations.
• Contralateral lobe assessment by palpation is old-fashioned and inferior to ultrasonic assessment.
Introduction
Completion thyroidectomy is a unilateral reoperation on a previously untouched thyroid lobe (TL), which is performed to avoid the risk of recurrence on the contralateral lobe and to prepare for 131I ablation. Completion thyroidectomy is recommended for all patients with differentiated cancer (>10 mm) who have significant residual thyroid tissue remaining in the neck (131I uptake >5% over 24 h) [1]. The incidence of bilateral thyroid carcinoma reported in the literature ranges from 30 to 88%, depending on the extent of primary surgery [1–3]. No initial tumor feature reliably predicts the presence of tumor on the second side [4], except for multifocality. The use of postoperative radioiodine therapy decreases the recurrence rate and distant metastasis, improving survival when compared with unilateral thyroid lobectomy [5]. Furthermore, completion thyroidectomy permits tumor surveillance by thyroglobulin measurements. To avoid completion thyroidectomy, try to obtain a correct diagnosis before initial surgery with preoperative ultrasound, fine needle aspiration cytology (FNA) and intraoperative frozen section. Nevertheless, FNA and frozen section are not absolutely reliable in the diagnosis of cancer, especially in follicular and oncocytic lesions [6]. Hence, for neoplasms >4 cm in diameter with these FNA results, prophylactic total thyroidectomy may be considered [1].
Practical Tips to Facilitate Completion Thyroidectomy
To avoid reoperations in previously dissected planes, total unilateral lobectomies, always including the isthmus and Lallouette's pyramid, are preferred to subtotal resections.
Assessing lymph nodes during the initial operation is important.
The recurrent and superior laryngeal nerves (RLN/SLN) and both PTs should be preserved at the original operation and their localization documented.
The inferior thyroid artery should not be ligated. A devascularized gland should be autotransplanted. Consider each PT as if it were the last one left, even in unilateral resection.
Intraoperative assessment of the contralateral lobe via palpation is useless. Ultrasonography is much more accurate.
Do not dissect between the sternothyroid muscle (STM) and the thyroid gland. If palpation is deemed necessary, it should be done between the STM and sternohyoid muscles (SHM) to prevent adhesions along the thyroid capsula [7].
Practical Tips to Perform Completion Thyroidectomy
The timing of completion thyroidectomy is important. Within 1 week, no dense adhesions occur. Therefore, reoperation should be performed no later than 5 days postoperatively or postponed for at least 3 months [8]. Psychologically, it is in the patient's best interest to reoperate as soon as possible.
Direct laryngoscopy should be performed in all cases before completion thyroidectomy, as 30-40% of unilateral RLN paralyses are asymptomatic [7]. Transient palsy can be a temporary contraindication for reoperation. In patients with definitive RLN palsy, the indication of completion thyroidectomy must be discussed and the risk of bilateral RLN palsy and the need for tracheostomy must be taken into consideration. In such cases, electromyographic monitoring of the RLN is strongly advised, if not in all reoperative thyroid surgery [9].
Preferably, the original scar is incised for access to the thyroid. Strap muscles are dissected in the midline and retracted laterally if they did not adhere to the TL as a result of former proper surgery. This is the ideal situation. In moderate adhesions, access is gained between the SHM and STM. If there is dense fibrosis, the posterolateral approach of Henry and Sebag [10] may be used. Direct RLN visualization is mandatory. In case of adhesions, the RLN is to be identified in a previously undissected area and then followed into the dissected area.
A meticulous review of previous operative notes and pathology for possible symmetry of parathyroids can be useful. To autotransplant devascularized PT, the operative specimen should be examined carefully before passing it on for pathological analysis.
Conclusion
When a unilateral thyroid lobectomy is indicated, the surgeon and cytopathologist should be careful not to complicate possible completion thyroidectomy. This implies obtaining a correct diagnosis at initial surgery, performing nothing but a total lobectomy with preservation of both PTs and RLN, and avoiding any dissection into the contralateral side. Therefore, when indicated, completion thyroidectomy is simply a unilateral operation on a previously undissected TL and a procedure that can be performed safely.
References
1 Pasieka JL, Thompson NW, McLeod MK, Burney RE, Macha M: The incidence of bilateral well-differentiated thyroid cancer found at completion thyroidectomy. World J Surg 1992;16:711–716.
2 Clark OH: Total thyroidectomy: the treatment of choice for patients with differentiated thyroid cancer. Ann Surg 1982;196:361–370.
3 Kim ES, Kim TY, Koh JM, Kim YI, Hong SJ, Kim WB, Shong YK: Completion thyroidectomy in patients with thyroid cancer who initially underwent unilateral operation. Clin Endocrinol (Oxf) 2004;61:145–148.
4 DeGroot LJ, Kaplan EL: Second operations for ‘completion’ of thyroidectomy in treatment of differentiated thyroid cancer. Surgery 1991;110:936–939.
5 Hamming JF, Van de Velde CJ, Goslings BM, Schelfhout LJ, Fleuren GJ, Hermans J, Zwaveling A: Prognosis and morbidity after total thyroidectomy for papillary, follicular and medullary thyroid cancer. Eur J Cancer Clin Oncol 1989;25:1317–1323.
6 Raber W, Kaserer K, Niederle B, Vierhapper H: Risk factors for malignancy of thyroid nodules initially identified as follicular neoplasia by fine-needle aspiration: results of a prospective study of one hundred twenty patients. Thyroid 2000;10:709–712.
7 Pasieka JL: Reoperative thyroid surgery; in Randolph GW (ed): Surgery of the Thyroid and Parathyroid Glands. Philadephia, Saunders, 2003, pp 385–391.
8 Tan MP, Agarwal G, Reeve TS, Barraclough BH, Delbridge LW: Impact of timing on completion thyroidectomy for thyroid cancer. Br J Surg 2002;89:802–804.
9 Timmermann W, Dralle H, Hamelmann W, Thomusch O, Sekulla C, Meyer T, Timm S, Thiede A: Does intraoperative nerve monitoring reduce the rate of recurrent nerve palsies during thyroid surgery (in German)? Zentralbl Chir 2002;127:395–399.
10 Henry JF, Sebag F: Lateral endoscopic approach for thyroid and parathyroid surgery. Ann Chir 2006;131:51–56.
Dr. Eveline Slotema
CHU La Timone
Department of General and
Endocrine Surgery
264, Rue St. Pierre
FR-13385 Marseille Cedex 05 (France)
E-Mail Eveline.SLOTEMA@ap-hm.fr
