Is There a Regular Pattern in the Recovery of Parathyroid Function After Thyroid Cancer Surgery?

Figures & data

Table 1 Clinical Characteristics of 183 Patients with PTC

Characteristics	Patients with PTC (n=183)
Age (years)	46.3±11.2
Gender (M/F),n	53/130
Tumor size(mm)	11.8±7.8
Extrathyroidal extension (yes/no),n	69/114
PGs mistakenly excised (yes/no),n	19/164
Implanted PGs (0/1/2),n	49/112/22
PGs preserved in situ (1/2/3/4),n	1/39/108/35
Central LNs retrieved,n	9.1±5.8
Positive central LNs,n	2.7±3.8
Lateral LNs retrieved,n	(n=37) 32.4±11.5
Positive lateral LNs,n	(n=37) 4.4±3.4
Postoperative hospital stay,n	5.1±1.8
Recurrent laryngeal nerve injury (yes/no),n	12/171
Postoperative bleeding (yes/no),n	2/181
TNM staging (I/II/III/IVa) ^α,n	152/31/0/0
Inpatient period
Hypocalcemia,n (%)	54(29.5)
Biochemical hypocalcemia, n (%)	51(27.9)
Symptomatic hypocalcemia,n (%)	15(8.2)
Hypo-iPTHemia,n (%)	80(43.7)
Intravenous calcium,n (%)	80(43.7)
After discharge
Transient hypocalcemia symptoms,n (%)	17(9.3)
Oral calcium,n (%)	99(54.1)
OC for 2 weeks,n (%)	17(9.3)
OC for 3 weeks,n (%)	77(42.1)
OC for 1 month,n (%)	5(2.7)
Intravenous calcium,n (%)	0(0)
Hypocalcemia 1 month postoperatively,n (%)	2(1.1)
Hypo-iPTHemia 1 month postoperatively,n (%)	5(2.7)

Note:^αAJCC 8th Edition.

Abbreviations: PTC, papillary thyroid carcinoma; PTH, parathyroid hormone; PG, PARATHYROID gland; LN, lymph node; OC,oral calcium.

Table 2 Serum Calcium and iPTH in 115 Patients

	sCa (mmol/l)	iPTH (mmol/l)
Preoperative	2.36±0.11	3.80(3.01, 4.65)
POD1	1.91±0.17	0.60(0.22, 1.41)
POD3	2.00±0.19	0.58(0.19, 1.26)
POD5	2.11±0.15	0.95(0.45, 1.73)
POD14	2.15±0.12	1.66(1.20, 2.35)
POD30	2.28±0.11	3.23(2.29, 4.10)

Abbreviations: sCa, serum calcium; iPTH, intact parathyroid hormone; POD, postoperative day.

Table 3 Comparison of Clinical Data Between “Group A (Uclnd)” and “Group B (Bclnd) “

Characteristics	“Group A” (n=97)	“Group B” (n=86)	Test Value	P-value
Age (years)	46.7±11.5	45.9±10.9	t=0.438	0.662
Gender (M/F),n	28/69	25/61	χ^2=0.001	0.976
Tumor size(mm)	10.9±5.8	12.8±9.5	t=−1.615	0.109
Extrathyroidal extension (yes/no),n	33/64	36/50	χ^2=1.193	0.275
PGs mistakenly excised (yes/no),n	3/94	16/70	χ^2=11.788	0.001
Implanted PGs (0/1/2),n	28/65/4	21/47/18	χ^2=11.693	0.001
PGs preserved in situ (1/2/3/4),n	0/5/69/23	1/34/39/12	χ^2=33.751	0.000
Central LNs retrieved,n	6.2±3.6	12.4±6.1	t=−8.186	0.000
Positive central LNs,n	1.5±2.1	4.1±4.8	t=−4.675	0.000
Lateral LNs retrieved,n	(n=13) 29.8±12.4	(n=24) 33.8±10.9	t=−1.018	0.315
Positive lateral LNs,n	3.0±1.8	5.2±3.8	t=−1.967	0.057
Postoperative hospital stay,n	4.6±1.5	5.6±1.8	t=−3.988	0.000
Recurrent laryngeal nerve injury (yes/no),n	6/91	6/80	χ^2=0.047	0.829
Postoperative bleeding (yes/no),n	1/96	1/85		1.000^α
TNM staging (I/II/III/IVa) ^α,n	79/18/0/0	73/13/0/0	χ^2=0.383	0.536

Note:^αAJCC 8th Edition.

Abbreviations: UCLND, unilateral central lymph node dissection; BCLND, bilateral central lymph node dissection;PG, parathyroid gland; LN, lymph node.

Table 4 Comparison of Serum Calcium and iPTH In “Group A (Uclnd)” and “Group B (Bclnd) “

Characteristics (mmol/l)	“Group A “ (n=97)	“Group B” (n=86)	Test Value (t-Value)	P-value
Preoperative sCa	2.36±0.10	2.37±0.11	−0.530	0.597
sCa on POD1	2.01±0.18	2.00±0.18	1.237	0.218
sCa on POD3	2.11±0.15	2.02±0.21	3.226	0.002
sCa on POD5	2.16±0.18 (n=29)	2.13±0.21 (n=35)	0.541	0.590
sCa on POD14	2.25±0.19 (n=9)	2.28±0.16 (n=12)	−0.392	0.699
sCa on POD30	2.31±0.13	2.29±0.10	1.467	0.144
Preoperative iPTH	4.20±1.40	4.11±1.75	0.386	0.700
iPTH on POD1	1.92±1.32	1.51±1.60	1.883	0.061
iPTH on POD3	1.75±1.22	1.08±0.95	4.165	0.000
iPTH on POD5	1.74±1.19 (n=27)	0.80±0.67 (n=34)	3.677	0.001
iPTH on POD14	2.30±0.92 (n=9)	1.61±0.7 (n=12)	1.854	0.079
iPTH on POD30	3.79±1.62	3.57±1.93	0.838	0.403

Abbreviations: sCa, serum calcium; iPTH, intact parathyroid hormone; UCLND, unilateral central lymph node dissection; BCLND, bilateral central lymph node dissection; POD, postoperative day.

Table 5 Comparison of Postoperative Data Between “Group A (Uclnd)” and “Group B (Bclnd)”

Characteristics	“Group A” (n=97)	“Group B” (n=86)	Test Value (χ^2 Value)	P-value
Inpatient period:
Hypocalcemia,n (%)	21(21.6)	33(38.4)	6.128	0.013
Biochemical hypocalcemia, n (%)	20 (20.6)	31(36.0)	5.398	0.020
Symptomatic hypocalcemia,n (%)	6 (6.2)	9(10.5)	1.109	0.292
Hypo-iPTHemia,n (%)	33 (34.0)	47 (54.7)	7.885	0.005
Intravenous calcium,n (%)	37 (38.1)	43(50.0)	2.604	0.107
After discharge:
Transient hypocalcemia symptoms,n (%)	7 (7.2)	10(11.6)	1.053	0.305
Oral calcium,n (%)	44 (45.4)	55(64.0)	6.346	0.012
OC for 2 weeks,n (%)	6 (6.2)	11(12.8)	2.360	0.124
OC for 3 weeks,n (%)	37 (38.1)	40(46.5)	1.309	0.252
OC for 1 month,n (%)^α	1 (1.0)	4(4.7)		0.189
Intravenous calcium,n (%)	0(0)	0(0)
Hypocalcemia 1 month postoperatively,n (%) ^α	0(0)	2 (2.3)		0.219
Hypo-iPTHemia 1 month postoperatively,n (%) ^α	1 (1.0)	4(4.7)		0.189
Hypocalcemia at 6 months postoperatively,n (%)	0(0)	0(0)
Hypo-iPTHemia at 6 months postoperatively,n (%) ^α	0(0)	2(2.3)		0.219
Hypocalcemia at 12 months postoperatively,n (%)	0(0)	0(0)
Hypo-iPTHemia at 12 months postoperatively,n (%) ^α	0(0)	2(2.3%)		0.219

Note:^αFisher’s exact probability method.

Abbreviations: PTH, parathyroid hormone; UCLND, unilateral central lymph node dissection; BCLND, bilateral central lymph node dissection; OC,oral calcium.

Figure 1 Changes in perioperative serum calcium in 115 patients.

Figure 2 Changes in perioperative iPTH in 115 patients.