Need for Completion Thyroidectomy in Patients Undergoing Lobectomy for Indeterminate and High-Risk Nodules: Impact of Intra-Operative Findings and Final Pathology

Current guidelines increasingly suggest the use of thyroid lobectomy for indeterminate (Bethesda 3 and 4) and high-risk (Bethesda 5 and 6) thyroid nodules; however, the clinical reality is often very different.

The aim of this study was to determine the rate of completion thyroidectomy (CTx) for indeterminate and high-risk thyroid nodules which are pre-operatively classified as suitable for unilateral resection (lobe eligible) based on current guidelines. Seven hundred consecutive patients with thyroid nodules and FNA cytology over four years (2015–2018) were reviewed.

Distribution of the dominant nodules by Bethesda was: non-diagnostic 3.9%, benign 28.1%, atypia of unknown significance 19.0%, follicular neoplasm 23.6%, suspicious for malignancy 6.1% and malignancy 19.3%. Of 298 indeterminate nodules, 68.8% (205/298) had relative but independent indications for a total thyroidectomy (TTx) and the remainder were candidates for lobectomy. For these lobe eligible patients, the overall risk of ultimately needing a TTx was 19.4% (18/93), comprising 4.3% (4/93) from intra-operative findings and 15.7% (14/89) from final pathology. Similarly, of 170 high-risk nodules, 63.5% (108/170) had upfront indications for a TTx and the remaining 62 nodules were lobe eligible. Of the patients taken to the operating room for a lobectomy, 21.0% (13/62) were upgraded to a TTx intra-operatively and 26.5% (13/49) post-operatively. The lobe success rate for indeterminate nodules was 25.2% and for high-risk nodules was 21.2%. The rate of CTx, or the proportion of patients needing a second operation was 15.7% (14/89) and 26.5% (13/49), respectively.

In counselling a patient for surgery, the risk of needing a more radical initial procedure or second surgery needs to be accurately explained. There are three points of care that can influence operative strategy, pre-operatively by way of high-risk clinical factors, intra-operatively via anatomical findings and post-operatively in response to unrecognized pathological features. Additionally, the patient’s personal value judgment and level of risk aversion should be taken into consideration.