Hinson Andrew M, Lawson Bradley R, Franco Aime T, Stack Brendan C
Department of Otolaryngology-Head and Neck Surgery, University of Arkansas for Medical Sciences, Little Rock.
Department of Otolaryngology-Head and Neck Surgery, University of Arkansas for Medical Sciences, Little Rock2Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts.
JAMA Otolaryngol Head Neck Surg. 2017 Jun 1;143(6):595-600. doi: 10.1001/jamaoto.2016.4635.
Parathyroid biopsy represents a means for normal and hyperfunctional glands to be distinguished intraoperatively. However, no data exist to guide surgeons regarding how much of a parathyroid gland must be biopsied to satisfy the 20% rule.
To quantify the relative proportion of a hyperfunctional parathyroid gland that must be evaluated with the gamma probe to satisfy the 20% rule.
DESIGN, SETTING, AND PARTICIPANTS: A retrospective review of surgical data for 24 consecutive patients (16 women, 18 men; mean [SD] age, 66.6 [10] years; range, 51-83 years) who underwent surgery for primary hyperparathyroidism between May and October, 2015, in a tertieary academic medical center.
Extirpated parathyroid glands were sectioned into parallel or pie-shaped biopsies and evaluated ex vivo with a gamma probe to determine what percentage of a hyperfunctional gland must be sampled to meet the Norman 20% rule. The hypothesis was formulated during data collection.
In total, 253 ex vivo biopsy specimens were obtained from 33 surgically removed parathyroid glands. Parathyroid biopsies satisfied the 20% rule with an accuracy that depended on the relative proportion of the parent gland represented: half or more (96.6%; 95% CI, 91.7%-100.0%), a quarter to one-half (87.0%; 95% CI, 79.3%-94.7%), less than a quarter (63.6%; 95% CI, 54.5%-72.8%). When less than a quarter of the gland was removed, pie-shaped biopsies were more likely to satisfy the 20% rule compared with parallel biopsies of the same weight (78.4% vs 56.2%; absolute difference, 22.2%; 95% CI, 4.7%-39.7%).
Unless half of a parathyroid gland is biopsied during radioguided parathyroidectomy, the 20% rule cannot reliably rule out the presence of a hyperfunctional parathyroid lesion. Pie-shaped biopsies originating from the center of the gland are associated with a lower rate of false-negative results compared with peripheral biopsies of similar size. Pie-shaped biopsies and biopsy of half or more of each nonexcised parathyroid gland for ex vivo counts may increase the risk of remnant devascularization and resultant hypoparathyroidism.
甲状旁腺活检是术中区分正常和功能亢进腺体的一种方法。然而，目前尚无数据指导外科医生应取多少甲状旁腺组织进行活检才能满足20%规则。
量化功能亢进甲状旁腺中必须用γ探测仪评估以满足20%规则的相对比例。
设计、地点和参与者：对2015年5月至10月在一家三级学术医学中心接受原发性甲状旁腺功能亢进手术的24例连续患者（16例女性，8例男性；平均[标准差]年龄，66.6[10]岁；范围，51 - 83岁）的手术数据进行回顾性分析。
将切除的甲状旁腺切成平行或扇形活检组织，并在体外用γ探测仪进行评估，以确定必须取样多少功能亢进的腺体才能符合诺曼20%规则。该假设在数据收集期间形成。
总共从33个手术切除的甲状旁腺中获得了253个体外活检标本。甲状旁腺活检符合20%规则的准确性取决于所取活检组织占母腺的相对比例：一半或更多（96.6%；95%置信区间，91.7% - 100.0%）、四分之一至一半（87.0%；95%置信区间，79.3% - 94.7%）小于四分之一（63.6%；95%置信区间，54.5% - 72.8%）。当切除的腺体小于四分之一时，与相同重量的平行活检相比，扇形活检更有可能符合20%规则（78.4%对56.2%；绝对差异，22.2%；95%置信区间，4.7% - 39.7%）。
在放射性引导甲状旁腺切除术中，除非对甲状旁腺进行一半或更多的活检，否则20%规则不能可靠地排除功能亢进甲状旁腺病变的存在。与类似大小的周边活检相比，从腺体中心取材的扇形活检假阴性率较低。扇形活检以及对每个未切除甲状旁腺的一半或更多进行活检以进行体外计数可能会增加残余腺体缺血和导致甲状旁腺功能减退的风险。
