SUBTOTAL THYROIDECTOMY AND CERVICAL BLOCK DISSECTION: ITS EFFECT ON GRAVES' OPHTHALMOPATHY AND THYROID FUNCTION | ||
| The Egyptian Journal of Surgery | ||
| Volume 19, Issue 2, April 2000, Pages 115-123 PDF (1008.08 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/ejsur.2000.378650 | ||
| Author | ||
| Mosaad Soliman* | ||
| Mansoura University Hospital, Department of Surgery Mansoura, Egypt. | ||
| Abstract | ||
| The thyroid gland and or cervical lymph nodes have been implicated as the major source of synthesis and secretion of TSAb responsible for the hyperthyroidism of Graves' disease (GD). Although an immunogenic pathogenesis of Graves' ophthalmopathy (GO) has been proposed, the actual mechanisms of retrobulbar involvement are not well defined. To determine whether cervical lymph nodes might have a role in the development of GO and whether these nodes participate in the activation of thyroid tissue remnant following subtotal thyroidectomy and hence recurrence of hyperthyroidism, we examined the effect of cervical lymphadenectomy on GO and thyroid function after subtotal thyroidectomy. A series of 30 patients who had GD with varying degrees of GO were included in this study. Subtotal thyroidectomy and excision of cervical lymph nodes as well as lymphatic trunks was carried out in 15 patients (group A). While subtotal thyroidectomy alone was done in the other 15 patients (group B). Exophthalmometry, TSAb level and magnetic resonance imaging (MRI) of the orbit were done before surgery and also 1 month, 6 months and yearly for 3 years thereafter. There was a statistically significant reduction in exophthalmometric measures, 6 months postoperatively in group A compared to group B. There was a further reduction at 1 year and was the same at subsequent periods. One month after surgery, TSAb levels decreased significantly in group A compared to group B. A further decrease of TSAb levels was observed at 6 months and almost normalized at 1 year in group A. Six months after surgery, TASb levels in group B were higher than those in group A, but still lower than the values before surgery. MRI of the orbit in the presurgical period showed extraocular muscle enlargement of all patients with GD even those with no clinical ophthalmopathy. Six months postoperatively, there was a significant reduction in extraocular muscle thickness as well as the individual muscle/optic nerve ratio in group A compared to group B. There was a further reduction at 1 year and remained unchanged thereafter. Recurrence of hyperthyroidism was observed in one patient of group B, 3 years after surgery but in none of group A. A larger size of lymphatic trunks and greater number of lymph nodes was excised from the side of the neck corresponding to higher grade of exophthalmopathy. Conclusions (1) The observed improvement of exophthalmos following cervical lymph node dissection, implies the potential role of these nodes in the initiation of retrobulbar immunological process responsible for GO. Support for this observation comes from the fact that the side with greater exophthalmos had a larger number of lymph nodes and lymphatic trunks in the neck than on the contralateral side. (2) The significant reduction of TSAb level following lymph node dissection points to these nodes as a major source of TSAb which when reaches a pathological level in the circulation it could lead to recurrence of hyperthyroidism. (3) Subtotal thyroidectomy and cervical lymphadenctomy seems to be a logic alternative to the standard thyroidectomy in concern of its ameliorating effect on GO, moreover, it can be used to prevent progression of the process in patients without clinical evidence of GO (4) This operation could be used to prevent the recurrence of hyperthyroidism especially in patients with high preoperative TSAb titer. | ||
| Keywords | ||
| Thyroidectomy; block dissection; Graves' & Thyroid Function | ||
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