Department of General and Endocrine Surgery, Hopital Huriez CHU, Lille Cedex, 59037, France.
World J Surg. 2010 Jun;34(6):1181-6. doi: 10.1007/s00268-009-0363-1.
Clinical guidelines edited in 2006 by the American Thyroid Association (ATA) and stated in the European Thyroid Association Consensus (ETA) recommend routine central lymph node dissection (level VI neck dissection) in addition to thyroidectomy for the surgical treatment of differentiated thyroid cancer. This central dissection increases the incidence of postoperative hypocalcemia, which is related to the resection or devascularization of the inferior parathyroids together with bilateral thymectomy. Some authors perform unilateral thymectomy in order to minimize this complication. Our aim was to study the benefit/risk (incidence of thymic lymph node metastases versus postoperative hypocalcemia) of both procedures.
We retrospectively reviewed the records of 138 patients who underwent total thyroidectomy with central neck lymph node dissection for differentiated thyroid cancer between 2004 and 2007. Bilateral thymectomy was performed in 45 patients (group 1, 15 males and 30 females) and unilateral thymectomy was performed in 93 patients (group 2, 27 males and 66 females). Forty-two papillary and 3 medullary cancers were found in group 1, and 75 papillary, 2 follicular, and 17 medullary cancers were found in group 2. The presence of thymic metastases at pathology and the occurrence of postoperative hypocalcemia were reviewed.
Two cases of papillary thymic metastases were found in group 1. These were lymph node micrometastases localized in the ipsilateral side of the primary tumor in both cases. Transient hypocalcemia was significantly more frequent (P < 0.001) in group 1 than in group 2: 16 patients (35.5%) versus 10 (10.7%). There was one case of permanent hypocalcemia in group 1 after the follow-up period.
Bilateral thymectomy risk outweighs any likely carcinologic benefit. We do not recommend routine bilateral thymectomy during central neck dissection for differentiated thyroid cancer.
美国甲状腺协会（ATA）于 2006 年编辑的临床指南以及欧洲甲状腺协会共识（ETA）指出，对于分化型甲状腺癌的手术治疗，除甲状腺切除术外，还应常规进行中央淋巴结清扫术（VI 区颈部清扫术）。这种中央清扫术增加了术后低钙血症的发生率，这与下甲状旁腺的切除或血供破坏以及双侧胸腺切除术有关。一些作者进行单侧胸腺切除术以最小化这种并发症。我们的目的是研究这两种方法的获益/风险（胸腺样淋巴结转移的发生率与术后低钙血症的关系）。
我们回顾性分析了 2004 年至 2007 年间 138 例接受全甲状腺切除术加中央颈部淋巴结清扫术治疗分化型甲状腺癌的患者记录。45 例患者行双侧胸腺切除术（组 1，15 例男性和 30 例女性），93 例患者行单侧胸腺切除术（组 2，27 例男性和 66 例女性）。组 1 中发现 42 例乳头状和 3 例髓样癌，组 2 中发现 75 例乳头状、2 例滤泡状和 17 例髓样癌。病理检查发现胸腺转移的存在和术后低钙血症的发生。
组 1 中有 2 例发现甲状腺胸腺转移。这两个病例都是位于原发性肿瘤同侧的淋巴结微转移。组 1 中暂时性低钙血症的发生率明显高于组 2（P < 0.001）：16 例（35.5%）比 10 例（10.7%）。组 1 中有 1 例在随访期间发生永久性低钙血症。
双侧胸腺切除术的风险大于任何可能的抗癌益处。我们不建议在分化型甲状腺癌的中央颈部清扫术中常规行双侧胸腺切除术。
