Table 1.
Cohort specification and histomorphology
| Vienna (n = 21) | Bern (n = 4) | |
|---|---|---|
| Sex | ||
| Male | 12 (57.1%) | 1 (25.0%) |
| Female | 9 (42.9%) | 3 (75.0%) |
| Age at surgery (years) | x̄ = 41.3 (SD 9.1) | x̄ = 33.0 (SD 7.5) |
| Nephro-/urolithiasis | ||
| Yes | 3 (14.3%) | 1 (25.0%) |
| No | 16 (76.2%) | 2 (50.0%) |
| Not available | 2 (9.5%) | 1 (25.0%) |
| Kindred | ||
| Positive | 8 of 11 examined (72.2%) | 1 of 1 examined (100%) |
| Negative | 3 of 11 examined (27.8%) | 0 of 1 examined (0%) |
| Preoperative osteodensitometry | ||
| Normal | 0 | 1 (25.0%) |
| Osteopenia | 6 (28.6%) | 2 (50.0%) |
| Osteoporosis | 2 (9.5%) | 0 |
| Not available | 13 (38.1%) | 1 (25.0%) |
| Preoperative PTH (pg/ml) | x̄ = 154.3 (SD 153.3) | x̄ = 227.4 (SD 162.9) |
| Preoperative Ca (total, mmol/l) | x̄ = 2.8 (SD 0.4) | x̄ = 3.0 (SD 0.3) |
| Preoperative Ca (albumin-adjusted, nmol/l) | x̄ = 2.7 (SD 0.4) | x̄ = 2.9 (SD 0.1) |
| Preoperative albumin (g/l) | x̄ = 43.1 (SD 1.5) | x̄ = 37.5 (SD 4.9) |
| Preoperative creatinine (μmol/l) | x̄ = 76.5 (SD 20.5) | 50.0 (only one patient with data) |
| Preoperative 25-hydroxyvitamin D (nmol/l) | x̄ = 48.6 (SD 23.1) | x̄ = 30.8 (SD 1.7) |
| Surgical exploration | ||
| OMIP | 2 (9.5%) | 0 |
| UNE | 1 (4.8%) | 0 |
| BNE | 18 (85.7%) | 4 (100%) |
| Parathyroid glands identified | ||
| Four glands | 15 (71.4%) | 2 (50.0%) |
| Three glands | 2 (9.5%) | 2 (50.0%) |
| ≤ 2 glands | 2 (9.5%) | 0 |
| Not available | 2 (9.5%) | 0 |
| Parathyroidectomy | ||
| Total (min. four glands with autotransplantation) | 12 (57.1%) | 2 (50.0%) |
| Subtotal (three glands) | 3 (25.0%) | 2 (50.0%) |
| Less than subtotal (≤ 2 glands) | 6 (28.6%) | 0 |
| Thymectomya | ||
| Yes | 13 (61.9%) | 0 |
| No | 8 (38.1%) | 4 (100%) |
| Follow-up (months) | x̄ = 85.6 (SD 76.4) | x̄ = 101.5 (SD 162.9) |
| Persistenceb | 0 | 0 |
| Recurrencec | 3 (14.3%) | 2 (50.0%) |
| Time to recurrence (months) | x̄ = 170.3 (SD 101) | x̄ = 83 (SD 106.1) |
| Histomorphology | ||
| (Micro-)nodules per adenoma | x̄=2.6 (maximum 6) | x̄=8.3 (maximum 12) |
| Presence of septa | 13 (61.9%) | 4 (100%) |
| Rim of atrophic parathyroid tissue | ||
| Yes | 4 (19.0%) | 1 (25.0%) |
| No | 17 (81.0%) | 3 (75.0%) |
| Cystic configuration | 16 (76.2%) | 4 (100%) |
| Main cell type | ||
| Chief cell | 16 (76.2%) | 2 (50.0%) |
| Oxyphilic | 4 (19.0%) | 2 (50.0%) |
| Water clear | 1 (4.8%) | 0 |
| Presence of a fibrous capsule | 17 (81.0%) | 2 (50.0%) |
BNE bilateral neck exploration, Ca calcium, OMIP open minimally invasive parathyroidectomy, PTH parathyroid hormone, SD standard deviation, UNE unilateral neck exploration, x̄ mean
aThymectomy is defined as a complete resection of the (remaining) thymus
bPersistence designates biochemical hyperparathyroidism within the first 6 months postoperatively
cRecurrence designates biochemical hyperparathyroidism after six months of normal parathyroid function