Hypoparathyroidism following total thyroidectomy: high rates at a low-volume, non-parathyroid institution

Abstract

BackgroundHypoparathyroidism following total thyroidectomy is globally the most common complication to thyroid surgery. The reported complication rates vary widely and might be highly dependent on the surgical experience. In this study we aimed to evaluate the rate of hypoparathyroidism following primary total thyroidectomy at a low-volume institution that only performs thyroid surgery and does not have any experience with parathyroid surgery.MethodsRetrospective cohort study. All patients undergoing primary total thyroidectomy at the ENT-Department, Goedstrup Hospital, Denmark, over a 5-year period (2016-2020) were identified through the procedure codes for total thyroidectomy. Medical records, pathology reports, biochemical and medical histories were fully assessed for each patient. The primary endpoint was the rate of hypoparathyroidism- both immediate and permanent. Secondary outcomes were parathyroid gland identification rates, rates of parathyroid gland autotransplantation, and rates of inadvertent parathyroid gland excision.ResultsA total of 89 patients were included in the final analysis. A total of 33 patients (37.1%) experienced immediate hypoparathyroidism following surgery, while 30 patients (33.7%) still were on active vitamin D two months postoperatively. One year following surgery, 28 patients (31.5%) were still on active vitamin D and were considered as having permanent hypoparathyroidism. Sixty-one percent of the parathyroid glands were identified intraoperatively, and 19% of the patients experienced parathyroid autotransplantation. Inadvertent parathyroid gland excision occurred for 21% of the patients and was associated with a significantly increased risk of permanent hypoparathyroidism (RR = 2.99; 95% CI: 1.36 – 6.62, p = 0.005).ConclusionBoth transient and permanent hypoparathyroidism following total thyroidectomy at a low-volume, non-parathyroid institution occurred with much higher frequencies than previously reported. The elevated rates were most likely due to the low-volume, non-parathyroid nature of the surgeons which in part was mirrored in low parathyroid gland identifications rates, and high rates of autotransplantation and inadvertent parathyroid gland excision.

Autofluorescence-Guided Total Thyroidectomy in Low-Volume, Nonparathyroid Institutions

“…The control group consisted of 89 patients who were identified in the historical cohort where NIRAF was not used (mean [SD] age, 49.7 [12.8] years; 78 [88%] female). 13 Surgical procedures in the historical cohort were performed by a total of 6 surgeons. Three of the surgeons performed surgical procedures in both the NIRAF group and the control group.…”

“…The primary outcome was assessed at the end of follow-up in November 2023 and was defined as the rate of postoperative hypoPT (both immediate and permanent) compared with a historical cohort of successive patients undergoing primary total thyroidectomy between 2016 and 2020 before NIRAF was used (control group). 13 The control group was identified through the procedure codes for total thyroidectomy (NOMESCO Classification of Surgical Procedures: KBAA25 and KBAA60). Secondary outcomes were PG identification rates, rates of autotransplantation, and inadvertent PG excision.…”

“…12 In addition, recent studies have also found that permanent hypoPT occurs with much higher frequencies than previously reported, reaching up to 36%. [13][14][15][16][17][18] Thus, the severity and significance of this condition is potentially of much larger magnitude than previously assumed.…”

“…[19][20][21] Especially low-volume thyroid surgeons who do not perform parathyroid surgery seem to find PG identification particularly challenging, resulting in an increased risk of PG damage and subsequent hypoPT. 13,14,17,[22][23][24] In recent years, the use of intraoperative near-infrared autofluorescence (NIRAF) during thyroid surgery has gained traction. [25][26][27][28][29][30] Near-infrared autofluorescence refers to PGs ability to fluoresce when excited with light at the near-infrared wavelength of 785 nm.…”

“… 19 , 20 , 21 Especially low-volume thyroid surgeons who do not perform parathyroid surgery seem to find PG identification particularly challenging, resulting in an increased risk of PG damage and subsequent hypoPT. 13 , 14 , 17 , 22 , 23 , 24 …”