To evaluate the incidence of inadvertent parathyroidectomy, identify risk factors, determine the location of inadvertently excised glands, review pathology reporting in inadvertent parathyroidectomy, and explore relationships between inadvertent parathyroidectomy and post-surgical hypoparathyroidism or hypocalcaemia.

A retrospective cohort study of 899 thyroidectomies between 2015 and 2020 was performed. Histopathology slides of patients who had an inadvertent parathyroidectomy and a random sample of patients without a reported inadvertent parathyroidectomy were reviewed.

Inadvertent parathyroidectomy occurred in 18.5 per cent of thyroidectomy patients. Central neck dissection was an independent risk factor (inadvertent parathyroidectomy = 49.4 per cent with central neck dissection, 12.0 per cent without central neck dissection, p < 0.001). Most excised parathyroid glands were extracapsular (53.3 per cent), followed by subcapsular (29.1 per cent) and intrathyroidal (10.9 per cent). Parathyroid tissue was found in 10.2 per cent of specimens where no inadvertent parathyroidectomy was reported. Inadvertent parathyroidectomy was associated with a higher incidence of six-month post-surgical hypoparathyroidism or hypocalcaemia (19.8 per cent who had an inadvertent parathyroidectomy, 7.7 per cent without inadvertent parathyroidectomy).

Inadvertent parathyroidectomy increases the risk of post-surgical hypoparathyroidism or hypocalcaemia. The proportion of extracapsular glands contributing to inadvertent parathyroidectomy highlights the need for preventative measures.

This systematic review aimed to establish the evidence behind the use of pre-operative calcium, vitamin D or both calcium and vitamin D to prevent post-operative hypocalcaemia in patients undergoing thyroidectomy.

This review included prospective clinical trials on adult human patients that were published in English and which studied the effects of pre-operative supplementation with calcium, vitamin D or both calcium and vitamin D on the rate of post-operative hypocalcaemia following total thyroidectomy.

Seven out of the nine trials included reported statistically significantly reduced rates of post-operative laboratory hypocalcaemia (absolute risk reduction, 13–59 per cent) and symptomatic hypocalcaemia (absolute reduction, 11–40 per cent) following pre-operative supplementation.

Pre-operative treatment with calcium, vitamin D or both calcium and vitamin D reduces the risk of post-operative hypocalcaemia and should be considered in patients undergoing total thyroidectomy.

To determine whether pre-operative serum 25-hydroxyvitamin D has an impact on post-operative parathyroid hormone and serum calcium levels in patients undergoing total thyroidectomy for benign goitre.

This single-centre, retrospective study comprised 246 unselected surgical patients who had undergone total thyroidectomy for bilateral, benign, multinodular goitre. The correlation between pre-operative serum 25-hydroxyvitamin D and post-operative serum parathyroid hormone and serum calcium was studied to determine whether low pre-operative serum 25-hydroxyvitamin D was predictive of post-operative hypocalcaemia.

Seventy-nine patients (32 per cent) had post-operative hypocalcaemia. Eighteen patients (7.32 per cent) experienced unintentional parathyroidectomy (1 parathyroid gland in 15 patients, 2 parathyroid glands in 3 patients). In univariate analysis, pre-operative serum 25-hydroxyvitamin D was not correlated with post-operative serum calcium (p = 0.69) or post-operative serum parathyroid hormone (p = 0.5804). Furthermore, in multivariate analysis, which took into account unintentional parathyroidectomy, no correlation was found (p = 0.33). Bilateral unintentional parathyroidectomy was statistically associated with post-operative hypocalcaemia (p = 0.032).

Pre-operative serum 25-hydroxyvitamin D did not appear to have any impact on post-operative serum calcium in patients undergoing total thyroidectomy for benign goitre.

To develop a practical, efficient and predictive algorithm to manage potential or actual post-operative hypocalcaemia after complete thyroidectomy, using a single post-operative parathyroid hormone assay.

This paper reports a prospective study of 59 patients who underwent total or completion thyroidectomy over a period of 24 months. Parathyroid hormone levels were checked post-operatively on the day of surgery, and all patients were evaluated for hypocalcaemia both clinically and biochemically with serial corrected calcium measurements.

No patient with an early post-operative parathyroid hormone level of 23 ng/l or more (i.e. approximately twice the lower limit of the normal range) developed hypocalcaemia. All the patients who initially had post-operative hypocalcaemia but had an early parathyroid hormone level of 8 ng/l or more (i.e. approximately two-thirds of the lower limit of the normal range) had complete resolution of their hypocalcaemia within three months.

Early post-operative parathyroid hormone measurement can reliably predict patients at risk of post-thyroidectomy hypocalcaemia, and predict those patients expected to recover from temporary hypocalcaemia. A suggested post-operative management algorithm is presented.