Parathyroid autotransplantation during thyroidectomy. Results of long-term follow-up.

SUMMARY BACKGROUND DATA: Permanent hypoparathyroidism is a recognized complication of thyroidectomy. Operative strategies to prevent this complication include preservation of parathyroid glands in situ and autotransplantation of parathyroid glands resected or devascularized during thyroidectomy. METHODS: An analysis of 194 patients having thyroidectomy and simultaneous parathyroid autotransplantation at Barnes Hospital from 1990 to 1994 was performed. Data were collected regarding patient demographics, indication for thyroidectomy, operative procedure, pathologic diagnoses, and postoperative course, including biochemical assessment of parathyroid autograft function. RESULTS: Of 194 patients having either total, subtotal, or completion thyroidectomy, 104 (54%) experienced a [Ca(+2)]nadir less than or equal to 8.0 mg/dL and had symptoms and signs of hypocalcemia. Parathyroid autotransplantation was successful in 103 (99%) of these 104 cases and resulted in a 1.0% incidence of hypoparathyroidism in this series. CONCLUSIONS: Although preservation of parathyroid glands in situ is desirable, routine parathyroid autotransplantation during thyroidectomy virtually eliminates postoperative hypoparathyroidism. Normal parathyroid glands resected or devascularized during thyroidectomy for well-differentiated thyroid carcinoma or benign disease should be transplanted in the sternocleidomastoid muscle. Patients with Multiple Endocrine Neoplasia type 2A should have parathyroid glands resected at the time of thyroidectomy for medullary thyroid carcinoma and transplanted in the nondominant forearm. Postoperative management in most patients after thyroidectomy and parathyroid autotransplantation involves temporary calcium and vitamin D replacement and close biochemical evaluation. This precautionary measure of parathyroid autotransplantation markedly reduces the incidence of permanent postoperative hypoparathyroidism.     

Routine parathyroid autotransplantation during thyroidectomy

BACKGROUND: Parathyroid autotransplantation (PTHAT) during thyroidectomy has been shown to reduce the incidence of permanent hypoparathyroidism. Although selective PTHAT is most commonly adopted, the value of routine PTHAT has not been well documented. METHODS: From January, 1998 to March, 1999, an operative strategy incorporating routine autotransplantation of at least 1 parathyroid gland was used during thyroidectomy. The postoperative outcome of patients (n = 118) was evaluated and compared with patients (n = 271) operated during a policy of selective PTHAT (January, 1995 to October, 1997). RESULTS: Two or more parathyroid glands were autotransplanted in 26 patients (22%) while 92 patients (78%) received autotransplantation of 1 parathyroid gland. Postoperative hypocalcemia occurred in 29 patients (25%) and 2 patients (1.7%) had permanent hypocalcemia develop. When a policy of selective PTHAT was adopted, 98 patients (36%) underwent PTHAT, and 5 patients developed permanent hypocalcemia (1.8%). The incidence of postoperative hypocalcemia was higher in patients who underwent routine PTHAT (25%) compared with that in patients who underwent selective PTHAT (15%) (P =.014). In addition, the operating time was significantly longer when routine PTHAT was adopted (153 minutes vs 130 minutes; P <.001). CONCLUSIONS: A low incidence of permanent hypoparathyroidism can be achieved by either routine or selective PTHAT during thyroidectomy but routine PTHAT is associated with a high incidence of postoperative hypocalcemia.     

Autotransplantation of at least one parathyroid gland during thyroidectomy in benign thyroid disease minimizes the risk of permanent hypoparathyroidism

OBJECTIVE:Permanent hypoparathyroidism is a distressing complication of thyroid surgery. The reported incidence varies between 0.4 and 13.8 % and is directly correlated to the extent of thyroidectomy. The aim of this retrospective study was to analyze whether simultaneous autotransplantation of at least one parathyroid gland during total thyroidectomy for benign thyroid disease could reduce the risk of permanent hypoparathyroidism. METHODS: Since 01/1999 all thyroid operations are prospectively recorded. Beside daily postoperative measurement of serum calcium level, iPTH is routinely determined on the third post op day. Patients with complications are followed closely. Postoperative hypoparathyroidism persisting for more than 6 months is defined permanent. RESULTS: Between 01/1999 and 02/2001 146 total thyroidectomies for benign thyroid disease have been performed (81 pat. with Graves disease, 62 with nodular goiter, 3 with thyroiditis de Quervain/Hashimoto). In 37 pat. (25 %) at least one parathyroid gland was simultaneously autotransplanted into the ipsilateral sternocleidomastoid muscle. Group I (no parathyroid autotransplantation, n = 109) and group II (parathyroid autotransplantation, n = 37) were comparable concerning patient age, thyroid disease and lowest post op calcium level (2.07 versus 2.05 mmol/l). The incidence of postoperative symptomatic hypocalcemia (14.7 % versus 21.6 %) and temporary hypoparathyroidism (15.6 % versus 18.9 %) was higher in group II patients (n. s.). Conversely, permanent hypoparathyroidism occurred exclusively in group I patients (2.75 %), patients with parathyroid autotransplantation (group II) did not develop this complication. CONCLUSIONS: Simultaneous autotransplantation of at least one parathyroid gland during total thyroidectomy for benign thyroid disease seems to minimize the risk of permanent hypoparathyroidism. The potential of routine autotransplantation in this setting has to be evaluated. The incidence of postoperative temporary hypocalcemia may be elevated with this policy.     

Parathyroid autotransplantation during thyroidectomy: is frozen section necessary?

OBJECTIVE: To evaluate the accuracy of parathyroid gland identification and the need for routine frozen section examination before parathyroid autotransplantation during thyroidectomy. DESIGN: A prospective case series. SETTING: An endocrine surgical unit. PATIENTS: From January 1, 1995, to December 31, 1997, parathyroid autotransplantation was attempted for devascularized or inadvertently removed glands in 152 (33.7%) of 450 patients during thyroidectomy. Before autotransplantation, a biopsy specimen of the transplanted tissue was sent for histological examination without frozen section confirmation. MAIN OUTCOME MEASURES: Positive identification of parathyroid tissue in microscopic examination. RESULTS: Of 179 attempted autotransplantations of parathyroid glands, parathyroid tissue was confirmed in 167 biopsy specimens (93.3%). Incorrect identification of parathyroid gland occurred in 12 instances. The tissue mistaken as parathyroid gland included fat in 6 cases, thyroid tissue in 4 cases, lymph node in 1 case, and thymus in 1 case. Transplantation of at least 1 parathyroid gland (range, 1-3) was confirmed in 144 patients. For patients with confirmed parathyroid autotransplantation at risk of hypoparathyroidism (n = 112), postoperative transient hypocalcemia occurred in 22 (19.6%), while no patient developed any permanent hypocalcemia during a median follow-up of 6 months. CONCLUSIONS: Devascularized or inadvertently removed parathyroid glands can be identified expeditiously without routine frozen section during thyroid surgery. Immediate autotransplantation should be performed and permanent hypoparathyroidism can be avoided with this measure.     

Does autoimmune thyroid disease affect parathyroid autotransplantation and survival?

Background: While the increased risk to parathyroid gland preservation has long been recognized during surgery for thyroid cancer, the effect of different benign pathological conditions on parathyroid preservation has not previously been reported. The aim of this study was to examine parathyroid viability in relation to autoimmune thyroid disease. Methods: This is a retrospective cohort study including all patients having an initial total thyroidectomy (TT) performed by this unit during the period 2004–2005. Results: A total of 628 patients underwent TT in the study period. For the Graves' disease cases, 45 (62.5%) required the autotransplantation of one or less parathyroid gland, whereas 27 (37.5%) required two or more glands to be autotransplanted. This was significantly higher than for the benign thyroid disease group in which the respective figures were 242 (77.6%) and 70 (22.4%) (P= 0.01). Of the lymphocytic thyroiditis cases, 61 (65.5%) required the autotransplantation of one or less gland, whereas 32 (34.4%) required the autotransplantation of two or more glands. This was also significantly higher (P= 0.03). Temporary hypocalcaemia was significantly higher when two or more glands were autotransplanted (23 out of 177, 13.2%) than one or less gland autotransplanted (18 out of 451, 4.0%, P < 0.01). However, the overall incidence of permanent hypoparathyroidism was 1.0%, and there was no significant difference between the groups. Conclusion: TT performed for Graves' disease and lymphocytic thyroiditis results in the autotransplantation of more parathyroid glands, leading to a higher incidence of temporary hypocalcaemia post‐operatively. Despite this, the incidence of permanent hypoparathyroidism remains low at 1%.     

达芬奇机器人甲状腺手术中甲状旁腺的损伤因素及保护

目的分析达芬奇机器人甲状腺手术中甲状旁腺损伤的相关因素,探讨甲状旁腺保护的方法,避免永久性甲状旁腺功能减退的发生。 方法回顾性分析2014年1月至2016年5月在济南军区总医院甲状腺乳腺外科行达芬奇机器人甲状腺手术的190例患者的临床资料,统计术后患者出现低甲状旁腺激素(PTH)及低血钙的发生率,分析术后发生甲状旁腺功能减退的相关因素,探讨术中如何保护甲状旁腺及其功能。 结果患者术后暂时性低PTH的发生率为20.53%(39/190),暂时性低血钙的发生率为23.68%(45/190),术后随访无永久性甲状旁腺功能减退发生。甲状腺全切术后低PTH、低血钙的发生率高于腺叶 ＋ 峡部切除术者(χ²＝14.789,11.604;P＝0.000,0.001)。行中央区淋巴结清扫的患者术后低PTH、低血钙的发生率高于未清扫者(χ²＝11.200,17.771;P＝0.001,0.000)。甲状旁腺原位保留者术后低PTH、低血钙的发生率低于切除后自体移植者(χ²＝5.536,4.851,6.140,5.453;P＝0.019,0.028,0.013,0.020)。 结论在达芬奇机器人甲状腺手术中,甲状腺全切除、中央区淋巴结清扫、甲状旁腺切除后自体移植是造成患者术后暂时性甲状旁腺功能减退的重要影响因素。在达芬奇机器人手术系统下,准确识别甲状旁腺,精细化手术操作,原位保护甲状旁腺及血供,是预防永久性甲状旁腺功能减退的有效方法。     

Recovery of parathyroid function after total thyroidectomy: long-term follow-up study

BACKGROUND: To prevent postoperative hypoparathyroidism following total thyroidectomy, the parathyroid glands are preserved in situ and/or resected or devascularized parathyroid glands are autotransplanted. A retrospective investigation was conducted utilizing biochemical and specific endocrine assessments to evaluate the difference in recovery of parathyroid function in the long term. METHODS: A total of 103 patients underwent total thyroidectomy at Second Department of Surgery, School of Medicine, Kagawa University between 1990 and 1998. These patients were divided into a preservation group (n = 17), with only preserved glands in situ; a combination group (n = 72), consisting of patients with one or more parathyroid glands preserved in situ and one or more autotransplanted parathyroid glands; and an autotransplantation group (n = 14), with only transplanted glands. RESULTS: The overall incidence of permanent hypoparathyroidism in the preservation group, the combination group, and the autotransplantation group was 0%, 1.4%, and 21.4%, respectively. The mean levels of intact parathyroid hormone in the preservation group, the combination group, and the autotransplantation group recovered to 102%, 107%, and 50% of the preoperative levels at 5-year follow up. CONCLUSION: The results of the present study suggest that parathyroid glands should be preserved in situ whenever possible, to promote better recovery of postoperative function, and that only autotransplantation produces inadequate recovery of long-term function.     

原位保留甲状旁腺血供及甲状旁腺自体移植术

目的 介绍甲状腺肿瘤手术中保护甲状旁腺血供及甲状旁腺自体移植的方法及疗效.方法 46例全甲状腺切除或近全切除手术中,血管化甲状旁腺保留24例,单纯自体甲状旁腺移植5例,1～2枚甲状旁腺血管化保留同时其余甲状旁腺Ⅰ期自体移植17例.结果 应用此法行全甲状腺切除或近全切除患者中,有2例原位血管化保留甲状旁腺及3例血管化保留+自体甲状旁腺移植患者术后48～72 h内出现一过性低血钙,予以补钙后3 d左右恢复正常.2例单纯甲状旁腺自体移植患者术后出现低血钙,服用钙尔奇D/罗盖全4周～8周后复查血钙维持在正常水平.术后出现永久性甲状旁腺功能低下的仅1例(2.2%).结论 血管化甲状旁腺保留及自体甲状旁腺移植可大大降低全甲状腺切除或近全切除手术导致甲状旁腺功能低下的发生率.     

Parathyroid autotransplantation with total thyroidectomy for thyroid carcinoma: long-term follow-up of grafted parathyroid function.

BACKGROUND: Permanent hypoparathyroidism is a major complication of thyroidectomy. Autotransplantation of parathyroid glands has been attempted to prevent this complication. However, no direct data have been available to assess grafted parathyroid function after long-term follow-up in terms of the serum intact parathyroid hormone (PTH) concentration. METHODS: Eighty-four consecutive patients with differentiated thyroid carcinoma who underwent total thyroidectomy and bilateral modified neck dissection from 1992 to 1996 were enrolled. They concomitantly underwent total parathyroidectomy and autotransplantation of all parathyroid glands to the pectoralis major muscle. The serum intact PTH concentration was periodically measured as an index of grafted parathyroid function. RESULTS: The mean follow-up was 34 months. In all autotransplanted patients serum intact PTH concentrations fell below detectable limits immediately after surgery. They were restored to the normal range within 1 month postoperatively and were maintained during observation in 80 (95%) of 84 patients. Seventy-eight of 80 patients with normal intact PTH values were normocalcemic without any treatment and the remainder were normocalcemic with 1 microgram of 1 alpha-vitamin D3. Four hypoparathyroid patients were normocalcemic with 2 micrograms of 1 alpha-vitamin D3. The postoperative average serum intact PTH concentration of patients having more than 2 autotransplanted parathyroid glands was almost equal to that of patients with preservation of the parathyroid glands in situ. The incidence of permanent hypoparathyroidism was inversely correlated with the number of autotransplanted parathyroid glands. CONCLUSIONS: The recovery patterns of the intact PTH concentration indicate that the glands were grafted successfully and functioned for a long period. This feasible method of parathyroid autotransplantation bears comparison with the previous reports in terms of the incidence of permanent postoperative hypoparathyroidism, and it can be performed simply and is reproducible.     

Parathyroid Autotransplantation during Total Thyroidectomy—Does the Number of Glands Transplanted Affect Outcome?

Parathyroid autotransplantation is a technique for ensuring the continued function of parathyroid tissue at the time of total thyroidectomy (TT). The aim of this study was to ascertain whether the number of parathyroids transplanted affects the incidence of temporary and permanent hypoparathyroidism. A retrospective cohort study included all patients undergoing a TT in a single unit between July 1998 and June 2003. The number of parathyroids transplanted, the final pathology, and the incidence of temporary and permanent hypoparathyroidism were documented. Fisher’s exact test was used for statistical analysis. A total of 1196 patients underwent a TT during the 5 years studied. Of these, 306 (25.6%) had no parathyroids transplanted, 650 (54.3%), 206 (17.2%), 34 (2.8%) had 1,2, or 3 glands autotransplanted, respectively. The incidence of temporary hypoparathyroidism was 9.8% for no gland transplants, 11.9%, 15.1%, and 31.4% for 1,2,and 3 gland transplants, respectively (p < 0.05). The incidence of permanent hypoparathyroidism was 0.98%, 0.77%, 0.97%, and 0%, respectively (p = NS). The incidence of temporary hypoparathyroidism was higher when surgery was performed for Graves’ disease. Temporary hypocalcemia is closely related to the number of autotransplanted parathyroids during TT. The long-term outcome is not affected by the number of parathyroids autotransplanted. A “ready selective” approach to parathyroid autotransplantation is an effective strategy for minimizing the rate of permanent hypoparathyroidism.     

ROUTINE AUTOTRANSPLANTATION OF AT LEAST ONE PARATHYROID GLAND DURING TOTAL THYROIDECTOMY MAY REDUCE PERMANENT HYPOPARATHYROIDISM TO ZERO

Background : Permanent hypoparathyroidism, although a recognized complication of total thyroidectomy, is an outcome that all endocrine surgeons try to avoid. Methods : To minimize the risk of postoperative hypoparathyroidism a strategy was developed of routine autotransplantation of at least one parathyroid gland into the ipsilateral sternomastoid muscle during every total thyroidectomy. One hundred consecutive patients undergoing total thyroidectomy were included in the study. Serum calcium and albumin levels were measured pre-operatively, on the first 2 postoperative days, and after 2 weeks, or until return to normal serum calcium levels without calcium supplementation. If patients developed biochemical evidence or symptoms of hypocalcaemia postoperatively, a calcium replacement was administered according to defined protocol. Results : In 74 cases one parathyroid gland was autotransplanted: 44 for inadvertent removal or anatomical reasons, 19 because of devascularization (assessed by a cut through the gland’s capsule and evaluation of the capillary bleeding pattern), and 11 by protocol. In 25 cases, two or more glands were autotransplanted. Fourteen patients developed symptoms of hypocalcaemia and received calcium supplementation, as did another 13 asymptomatic patients with only biochemical evidence of hypocalcaemia. At follow-up 3 months postoperatively the incidence of permanent hypoparathyroidism was zero, with all patients being normocalcaemic without calcium supplementation. Conclusions : This strategy, easily adopted by any experienced surgeon, has the potential to eliminate permanent hypoparathyroidism following total thyroidectomy.     

Routine autotransplantation of at least one parathyroid gland during total thyroidectomy may reduce permanent hypoparathyroidism to zero.

BACKGROUND: Permanent hypoparathyroidism, although a recognized complication of total thyroidectomy, is an outcome that all endocrine surgeons try to avoid. METHODS: To minimize the risk of postoperative hypoparathyroidism a strategy was developed of routine autotransplantation of at least one parathyroid gland into the ipsilateral sternomastoid muscle during every total thyroidectomy. One hundred consecutive patients undergoing total thyroidectomy were included in the study. Serum calcium and albumin levels were measured pre-operatively, on the first 2 postoperative days, and after 2 weeks, or until return to normal serum calcium levels without calcium supplementation. If patients developed biochemical evidence or symptoms of hypocalcaemia postoperatively, a calcium replacement was administered according to defined protocol. RESULTS: In 74 cases one parathyroid gland was autotransplanted: 44 for inadvertent removal or anatomical reasons, 19 because of devascularization (assessed by a cut through the gland's capsule and evaluation of the capillary bleeding pattern), and 11 by protocol. In 25 cases, two or more glands were autotransplanted. Fourteen patients developed symptoms of hypocalcaemia and received calcium supplementation, as did another 13 asymptomatic patients with only biochemical evidence of hypocalcaemia. At follow-up 3 months postoperatively the incidence of permanent hypoparathyroidism was zero, with all patients being normocalcaemic without calcium supplementation. CONCLUSIONS: This strategy, easily adopted by any experienced surgeon, has the potential to eliminate permanent hypoparathyroidism following total thyroidectomy.     

Assessment of parathyroid autotransplantation for preservation of parathyroid function after total thyroidectomy

BACKGROUND: Hypoparathyroidism with permanent hypocalcemia is a well-recognized complication after thyroid surgery. AIM: This study was conducted to assess the role of immediate parathyroid autotransplantation in the preservation of parathyroid function after total thyroidectomy. PATIENTS AND METHODS: Twenty-eight patients had autotransplantation of parathyroid glands resected or devascularized during total thyroidectomy. Data were collected prospectively regarding demographics, indication for surgery, operative procedure, pathologic diagnosis, number of glands transplanted, and subsequent course. Thyroid nodules were evaluated by ultrasonography, radionuclide scanning, and/or fine-needle aspiration cytology. All patients had serum ionized calcium, phosphorus, and intact parathyroid hormone (PTH) levels measured preoperatively and monitored regularly postoperatively for a period of 14 weeks and again at 6 months after operation. Patients were categorized into three groups according to the number of glands transplanted: one (group 1, n = 6), two (group 2, n = 14), or three glands (group 3, n = 8). In three other volunteers, one parathyroid gland was transplanted in the brachioradialis and subjected to electron microscopy 1, 2, and 4 weeks after transplantation. RESULTS: Total thyroidectomy was performed for malignant disease in 16 patients (57.1%) and for benign disease in 12 (42.9%) patients. All patients reverted to asymptomatic normocalcemia without the need for any medications within 4 to 14 weeks. Normal levels of serum markers were regained slower when one gland was transplanted compared with two or three glands (P <.01). Electron microscopic examination showed evidence of ischemic degeneration in the transplanted tissues 1 week postoperatively. Regeneration started by the second week and coincided with normalization of PTH levels. Optimum resting and nearly normal status of parathyroid tissue was achieved by the fourth week. CONCLUSIONS: This study showed that active PTH production coincides with regeneration of parathyroid cells and that autotransplantation of at least two resected or devascularized glands during total thyroidectomy nearly eliminates permanent postoperative hypoparathyroidism, thus improving the safety of total thyroidectomy performed for malignant or benign disease.     

甲状腺全切术中甲状旁腺自体移植的现状和思考

甲状旁腺功能减退是甲状腺术后最常见的并发症之一,不仅增加患者的住院时间、费用,而且导致患者术后生活质量下降.外科医生及患者希望尽可能避免永久性甲状旁腺功能减退的发生,因此甲状旁腺自体移植作为一种简单、易行的防治策略,在甲状腺手术中广泛应用.但是移植旁腺功能的有效性尚未明确,术中甲状旁腺是否移植?还存在争议.通过文献复习...     

Retrieval of the parathyroid glands during thyroidectomy

A recommended technique of intraoperative search of the removed thyroid lobe or entire gland for attached parathyroid glands is presented. Diligent examination of the thyroid capsule and folds of the thyroid gland is made in the sterile operative field. Any recovered parathyroid gland or glands are then finely sectioned and reimplanted in a location which is not likely to be violated in any future surgical procedure. This technique has significantly reduced the incidence of permanent hypoparathyroidism after total thyroidectomy.     

Risk Factors of Hypoparathyroidism Following Total Thyroidectomy for Thyroid Cancer

Background

The risk factors responsible for hypoparathyroidism after total thyroidectomy have not been completely defined. The present study evaluated one surgeon’s personal experience of postoperative hypoparathyroidism after total thyroidectomy for thyroid cancer and predisposing risk factors of postoperative hypoparathyroidism.

Methods

We performed a retrospective analysis of 531 consecutive total thyroidectomy cases for thyroid cancer operated by single surgeon at the Center for Thyroid Cancer, National Cancer Center, Korea, from March 2003 to August 2006.

Results

Postoperative hypoparathyroidism occurred in 135 patients (25.4 %), 19 of whom (3.6 % of total patients) experienced permanent hypoparathyroidism. Parathyroid autotransplantation, bilateral central lymph node dissection, gross extrathyroidal extension, and the presence of parathyroid gland in the pathologic specimen were associated with postoperative hypoparathyroidism in multivariate analysis (p < 0.05, respectively). The presence of parathyroid gland in the pathologic specimen and the early period of surgeon’s practice were statistically significant risk factors for permanent hypoparathyroidism in multivariate analysis (p < 0.05, respectively).

Conclusions

Careful surgical technique for in situ preservation of parathyroid gland and autotransplantation of inadvertently removed parathyroid gland are important, especially in case of gross extrathyroidal extension. Adequate surgical experience is also an important factor. And routine bilateral central lymph node dissection should be done thoughtfully for its effect on postoperative hypoparathyroidism.     

纳米炭负显影及甲状旁腺自体移植在甲状腺乳头状癌手术中的应用

目的探讨纳米炭混悬注射液负显影联合甲状旁腺自体移植对甲状旁腺保护的临床意义。 方法回顾性分析2014年5月至2017年05月收治的134例甲状腺乳头状癌(TPC)患者临床资料,将67例注射纳米炭混悬注射液行甲状旁腺负显影及自体移植患者作为纳米炭组,67例常规手术患者作为对照组。应用SPSS17.0进行统计学处理,比较两组患者术后甲状旁腺误切率,手术后暂时性及永久性甲状旁腺功能减退的发生率,采用χ²检验,P<0.05差异有统计学意义。 结果纳米炭组甲状旁腺误切率10.44%(7/67)、暂时性甲状旁腺功能减退发生率10.44%(7/67)、永久性甲状旁腺功能减退发生率4.47%(3/67)明显低于对照组31.34%(21/67)、31.34%(21/67)、21.89%(14/67)差异有统计学意义(P<0.05)。 结论TPC根治术中通过纳米炭混悬注射液进行甲状旁腺负显影联合自体移植术,可有效减少甲状旁腺损伤,降低永久性甲状旁腺功能减退的发生率,提高手术安全性。     

Preserving Parathyroid Gland Vasculature to Reduce Post-thyroidectomy Hypocalcemia

Background

The failure to preserve parathyroid function in patients who have undergone total thyroidectomy is of major concern, because hypocalcemia is difficult to prevent and remains a common postoperative complication. Here, we describe procedures designed to preserve the vasculature supplying the parathyroid glands and examine both recent outcomes and retrospective reports of results obtained prior to the application of these preservation techniques.

Methods

Our technique for preserving parathyroid function during thyroidectomy was adopted in 2009 and involves separating a relatively long segment of a vessel distally from the thyroid gland. We reviewed the medical records of 1,411 patients who underwent total thyroidectomy, with or without lateral neck dissection, at the Samsung Medical Center from January 2006 through June 2014 to determine outcomes. Patients were divided into three groups according to the time period during which the surgery took place: Group A, 2006–2008 (before the vasculature-preserving technique was applied); Group B, 2009–2011 (the time when the technique was first adopted); and Group C, 2012–2014 (more recent results of the technique). We analyzed the incidence of hypoparathyroidism in the three groups, as well as risk factors that influenced its development.

Results

The rates of transient and permanent hypoparathyroidism in Group A were 25.4 and 4.3 %, respectively. However, the incidence of hypoparathyroidism decreased significantly over time after the vasculature-preserving procedure was adopted. Transient hypoparathyroidism developed in 4.8 % of Group C patients, and only four (0.7 %) of the 565 patients in this group required calcium supplementation, despite the fact that a greater number of patients were included who underwent total thyroidectomy combined with lateral neck dissection. Although female sex and lateral neck dissection tended to increase the rate of transient hypoparathyroidism, multivariate analysis showed that the vasculature-preserving procedure was the only significant risk factor related to postoperative hypoparathyroidism.

Conclusion

The blood flow of the final branch to the parathyroid gland is mostly in the lateral-to-medial direction; therefore, mobilization and preservation of the vessels lateral to the gland is essential to prevent devascularization of the parathyroid gland.

     

Applicability of Intraoperative Parathyroid Hormone Assay During Total Thyroidectomy as a Guide for the Surgeon to Selective Parathyroid Tissue Autotransplantation

Background Intraoperative parathyroid hormone assay (IOPTH) has been suggested to have value in predicting the development of postoperative hypoparathyroidism after thyroid surgery. IOPTH has been validated in identification of patients at risk of postoperative hypocalcemia requiring early onset of calcium supplementation therapy and in improving selection of patients eligible for a safe early discharge. However, the value of IOPTH has not been assessed in a randomized study as a guide for the surgeon to parathyroid tissue autotransplantation (PA). The objective of this study was to evaluate the applicability of IOPTH in guiding the surgeon to selective parathyroid tissue autotransplantation during total thyroidectomy (TT). Methods Between January 2005 and December 2005, 340 patients qualified for total thyroidectomy (TT) who met the inclusion criteria were randomized to two equal-sized groups (n = 170): group A, in which elective PA of at least one parathyroid gland was performed in all cases without IOPTH as a guide; and group B, in which selective IOPTH-guided PA was performed, if only the iPTH plasma level was <10 ng/L at 10–20 min after TT (before skin closure). The standard technique of PA consisting of implanting the parathyroid tissue into 10–20 sternocleidomastoid muscle pockets was used in both groups. IOPTH measurements were performed by the STAT-Intraoperative-iPTH-Assay. Serum calcium was routinely monitored at 4, 12, 24, 48, and 72 hr postoperatively. The incidence and severity of hypocalcemia and related symptoms were matched with the IOPTH results. On follow-up, serum calcium and plasma iPTH values were measured at 1, 3, and 6 months postoperatively. The primary end point was the success rate in preventing permanent postoperative hypoparathyroidism. The secondary end point was the use of postoperative medication for transient hypocalcemic symptoms. Results Twenty-one group B patients (12.3%) had plasma iPTH levels <10 ng/L at 10–20 min after TT (before skin closure) and they underwent selective IOPTH-guided PA. None of the patients from both groups experienced permanent postoperative hypoparathyroidism. Transient postoperative hypocalcemia occurred in 22.3% vs. 11.2% of patients (group A vs. B, respectively; p < 0.05). The mean cumulated serum calcium values were significantly lower for group A vs. group B patients within the entire 3-month period after TT (2.12 ± 0.09 mmol/L vs. 2.27 ± 0.05 mmol/L, respectively; p < 0.001). The mean oral calcium supplementation was significantly higher for group A vs. group B patients during the 3 months after TT (2.7 ± 0.9 g/day vs. 0.9 ± 0.4 g/day, respectively; p < 0.001). Conclusions IOPTH offers valuable information during TT, correctly identifying patients at risk of postoperative hypocalcemia. Selective IOPTH-guided PA in patients with plasma iPTH levels <10 ng/L at 10–20 min after TT reduces the risk of permanent postoperative hypoparathyroidism to zero, and this approach seems to be as effective as elective PA of at least one parathyroid gland without IOPTH guidance. Moreover, selective IOPTH-guided PA significantly decreases the incidence of transient postoperative hypoparathyroidism and the need for calcium supplementation therapy compared with elective PA without IOPTH. Presented at the 42^nd World Congress of Surgery, Montreal, Canada, August 26 to 30, 2007.     

Parathyroid autotransplantation during thyroidectomy: documentation of graft function.

HYPOTHESIS: Biochemical function of normal parathyroid tissue grafted during thyroidectomy can be documented. DESIGN: An intervention study in which devascularized or inadvertently removed parathyroid glands are reimplanted in forearm muscle pockets during thyroidectomy. Postoperative serum parathyroid hormone levels were evaluated by venous sampling from both forearms on postoperative days 1, 3, 14, 28, 56, and 84. SETTING: Tertiary care teaching hospital. PATIENTS: Seven patients undergoing thyroidectomy at risk for postoperative hypocalcemia. RESULTS: A 1.5-fold gradient of parathyroid hormone measurements between grafted and nongrafted arms was demonstrated in all patients on postoperative day 28. A maximal parathyroid hormone gradient was reached on day 56, and biochemical function persisted in 6 patients on day 84. CONCLUSIONS: Biochemical function of parathyroid glands reimplanted during thyroidectomy can be demonstrated objectively. The application of parathyroid autotransplantation may preserve parathyroid function for inadvertently removed or devascularized parathyroid glands during thyroid surgery.