Incidental parathyroidectomy during total thyroidectomy is not a direct cause of post‐operative hypocalcaemia
The preservation of parathyroid glands during thyroid operations is a technical challenge due to difficulty in identification, fragile vascular supply and variation in location.4 Iatrogenic hypocalcaemia post‐total thyroidectomy is a well‐recognized complication. Following total thyroidectomy, the incidence of transient hypocalcaemia may be as high as 50% and that of permanent hypocalcaemia 1.5–4%.5 Hypocalcaemia may take 24–48 h to manifest and for this reason many surgeons choose to either observe patients in hospital for 1 or 2 days, or routinely commence prophylactic calcium post‐operatively. The prevention and treatment of post‐thyroidectomy hypocalcaemia remain areas of ongoing debate.
Hypocalcaemia is a direct result of low circulating parathyroid hormone levels. This is usually due to trauma to the vascular supply of the parathyroid glands, or their complete removal. A number of risk factors have been implicated in post‐thyroidectomy hypocalcaemia including: incidental parathyroidectomy (IPE), extent of thyroidectomy, experience of surgeon and histopathology findings.3
IPE is the inadvertent removal of one or more parathyroid glands during thyroid surgery, which are subsequently identified within the pathological specimen.16 IPE is a theoretical risk factor for post‐operative hypocalcaemia.
This study aims to determine the incidence of incidental parathyroid excision in patients undergoing total thyroidectomy within a high volume specialist Endocrine Surgery Unit in an Australian metropolitan hospital, and to assess risk factors for IPE and the relationship between IPE and transient post‐operative hypocalcaemia in this patient group.