Central lymph node dissection as a secondary procedure for papillary thyroid cancer: Is there added morbidity?

Background

Routine central lymph node dissection (CLND) for papillary thyroid cancer (PTC) at the time of initial thyroidectomy has been advocated with a demonstrated decrease in post-ablation serum thyroglobulin compared to total thyroidectomy alone. Patients now present with central compartment metastatic disease after initial thyroid cancer surgery, or with a diagnosis of PTC after diagnostic lobectomy requiring completion thyroidectomy, and an undissected central compartment. Our aim was to compare the clinical outcomes in patients with PTC who underwent CLND as a secondary event with those having initial CLND.

Methods

A retrospective cohort study of 193 patients who underwent CLND for PTC between June 2002 and November 2007 was undertaken. Data gathered included patient demographics, number of lymph nodes excised, lymph node involvement, and incidence of postoperative complications.

Results

One-hundred and seventy (M/F: 28/142) patients (Grp A) had a CLND as part of their primary surgical procedure while 23 (M/F: 10/13) patients (Grp B) underwent CLND as a secondary procedure (12 therapeutic/11 prophylactic procedures). The mean number of lymph nodes sampled and the % involved in the 2 groups A and B were 9.2 vs 10.2 and 64% vs 61%, respectively. Similarly, the incidence of temporary hypocalcemia (12% vs 9%), permanent hypoparathyroidism (1.8% vs 0%), temporary recurrent laryngeal nerve (RLN) paresis (3% vs 4%), permanent RLN paresis (0.6% vs 0%), and wound infection (0.6% vs 4.3%) was comparable in groups A and B.

Conclusion

This study demonstrates that there is no additional morbidity when CLND is performed as a secondary procedure for patients with PTC. Secondary CLND should be performed in patients with proven central compartment metastatic disease after previous thyroidectomy and can be offered safely as a prophylactic procedure to patients at high risk for central lymph node metastasis when CLND has not been performed at initial primary operation for PTC.