Guerrero Marlon A, Evans Douglas B, Lee Jeffrey E, Bao Ruijun, Bereket Abby, Gantela Swaroop, Griffin Gary D, Perrier Nancy D
Michael E. DeBakey Department of Surgery, Baylor College of Medicine, One Baylor Plaza, Suite 404D, Houston, Texas 77030, USA.
World J Surg. 2008 May;32(5):836-9. doi: 10.1007/s00268-007-9437-0.
Parathyroid cryopreservation is used for potential autografting in patients who are rendered hypocalcemic following surgery. Cryopreservation employs multiple resources and carries a significant cost for processing and storage of tissue. Importantly, the length of time that parathyroid tissue remains functional after cryopreservation is not known. The goal of our study was to assess ex-vivo viability of parathyroid tissue in relation to the length of time in storage. We sought to define the appropriate time frame for tissue utilization and disposal to assist with long-term surgical planning.
From 1991 to 2006, 501 parathyroid specimens from 149 patients were cryopreserved at -80 degrees C according to standardized techniques. A single trained technician assessed viability, using a hemacytometer to count viable (clear cell) and nonviable (blue cell) tissue. Univariate analysis was performed to correlate length of preservation, diagnosis with viability.
We evaluated 106 random parathyroid specimens. Samples were divided into two groups: those stored>24 months and those stored<or=24 months. Eleven (10%) of 106 specimens were deemed viable. Length of storage time was associated with ex-vivo tissue viability. Viability of samples cryopreserved<or=24 months was 71% (10/14) versus 1% (1/92) of those specimens stored>24 months (p<0.001).
Viability of cryopreserved parathyroid cells is associated with duration of storage. Parathyroids preserved for greater than 24 months are unlikely to be viable. It seems reasonable to limit parathyroid cryopreservation to 24 months when frozen at -80 degrees C. Further studies are needed to optimize the process of cryopreservation to enhance cell viability.
甲状旁腺冷冻保存用于手术后发生低钙血症患者的自体移植。冷冻保存需要多种资源，并且组织处理和储存成本高昂。重要的是，甲状旁腺组织冷冻保存后保持功能的时间长度尚不清楚。我们研究的目的是评估甲状旁腺组织的体外活力与储存时间的关系。我们试图确定组织利用和处置的合适时间框架，以辅助长期手术规划。
1991年至2006年，按照标准化技术将149例患者的501个甲状旁腺标本在-80℃下冷冻保存。由一名经过培训的技术人员评估活力，使用血细胞计数器对活组织（透明细胞）和非活组织（蓝色细胞）进行计数。进行单因素分析以关联保存时间、诊断与活力。
我们评估了106个随机甲状旁腺标本。样本分为两组：储存时间>24个月的和储存时间≤24个月的。106个标本中有11个（10%）被认为具有活力。储存时间与体外组织活力相关。储存时间≤24个月的样本活力为71%（10/14），而储存时间>24个月的标本活力为1%（1/92）（p<0.001）。
冷冻保存的甲状旁腺细胞活力与储存时间有关。保存超过24个月的甲状旁腺不太可能具有活力。当在-80℃冷冻时，将甲状旁腺冷冻保存时间限制在24个月似乎是合理的。需要进一步研究以优化冷冻保存过程以提高细胞活力。
