IS THERAPY WITH CALCIUM AND VITAMIN D AND PARATHYROID AUTOTRANSPLANTATION USEFUL IN TOTAL THYROIDECTOMY FOR PREVENTING HYPOCALCEMIA?

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1 ORIGINAL ARTICLE IS THERAPY WITH CALCIUM AND VITAMIN D AND PARATHYROID AUTOTRANSPLANTATION USEFUL IN TOTAL THYROIDECTOMY FOR PREVENTING HYPOCALCEMIA? Bassam Abboud, MD, 1 Ghassan Sleilaty, MD, 1 Salam Zeineddine, MD, 1 Carla Braidy, MD, 1 Rony Aouad, MD, 2 Cyril Tohme, MD, 1 Roger Noun, MD, 1 Riad Sarkis, MD 1 1 Department of General Surgery, Hotel-Dieu de France Hospital, Faculty of Medicine, Saint-Joseph University, Beirut, Lebanon. dbabboud@yahoo.fr 2 Department of Otorhinolaryngology, Hotel-Dieu de France Hospital, Faculty of Medicine, Saint-Joseph University, Beirut, Lebanon Accepted 14 January 2008 Published online 29 April 2008 in Wiley InterScience ( DOI: /hed Abstract: Background. Routine calcium and vitamin D administration and routine autotransplantation of parathyroid glands can prevent hypocalcemia after total thyroidectomy. Methods. Routine autotransplantation of 1 or more parathyroid glands and oral calcium and vitamin D supplementation was used in 252 patients. Results. One, 2, or 3 parathyroid glands were autotransplanted in 223, 27, and 2 patients, respectively. Routine oral calcium and vitamin D was administered in postoperative period in all patients. Postoperative hypocalcemia occurred in 17%, of whom 1.6% had minor symptoms related to hypocalcemia. No patient developed permanent hypocalcemia during the followup period. The postoperative stay was 1 day in 93.6% of the cases. The incidence of postoperative hypocalcemia and hospital stay was higher in patients who underwent autotransplantation of more than 1 parathyroid gland. Conclusions. Routine oral calcium and vitamin D supplementation and autotransplantation of at least 1 parathyroid gland effectively reduced symptomatic hypocalcemia and permanent hypoparathyroidism in total thyroidectomy. VC 2008 Wiley Periodicals, Inc. Head Neck 30: , 2008 Keywords: thyroidectomy; autotransplantation; postoperative complications; permanent; hypocalcemia Correspondence to: B. Abboud VC 2008 Wiley Periodicals, Inc. Postoperative hypocalcemia is a well-known complication after total thyroidectomy, with reported incidences ranging from 1.6% to 50% and sometimes as high as 83%. 1 4 Although several authors have attempted to identify risk factors for postoperative hypocalcemia and hypoparathyroidism, 3 10 it is not easy to individually predict which patients will need calcium supplementation, vitamin D supplementation, or both, to prevent or treat symptoms. Fear of symptoms of hypocalcemia can increase the length of hospital stay for patients who otherwise would be discharged earlier. Routine oral calcium supplementation 1,11 has been proposed empirically to avoid the risk of hypocalcemic crisis, to shorten hospital length of stay, and to decrease costs after bilateral thyroid resection. 12,13 The effectiveness and safety of such an approach still need to be demonstrated. Moreover, there is no complete agreement about the type of supplementation therapy. Permanent hypoparathyroidism is a dread complication after thyroidectomy, with an incidence ranging from 1% to 32%. 14 Several strat Prevention of Hypocalcemia in Thyroidectomy HEAD & NECK DOI /hed September 2008

2 egies have been proposed for preserving parathyroid function during thyroidectomy. Aside from preservation of parathyroid glands by meticulous dissection, parathyroid autotransplantation has been advocated as another solution and has been increasingly performed to prevent permanent hypoparathyroidism during total, subtotal, or completion thyroidectomy for benign or malignant conditions of the thyroid. Some authors adopted a policy of selective parathyroid autotransplantation during thyroidectomy; others performed a more liberal routine parathyroid autotransplantation Patients who have undergone parathyroid autotransplantation had a significantly lower risk of permanent hypoparathyroidism once postoperative hypocalcemia occurred. Therefore, parathyroid autotransplantation was suggested for all thyroidectomies to preserve parathyroid function. However, the number of parathyroid glands and the amount of parathyroid tissue to be autotransplanted to avoid permanent hypoparathyroidism remain unclear. 14,16,17 In our previous study, 4 hypocalcemia developed in 40 of 215 patients (18.6%) who had total thyroid resection. Ten of 215 patients (4.7%) had symptoms related to hypocalcemia. In a multivariate analysis, independent risk factors for hypocalcemia were hyperthyroid status, bilateral surgical procedure, and parathyroid autotransplantation. During follow-up, 4 patients of 215 (1.9%) developed permanent hypoparathyroidism and needed supplement therapy with vitamin D and calcium. This study evaluates the effectiveness of a surgical strategy combining routine calcium and vitamin D supplementation with routine autotransplantation of at least 1 parathyroid gland during total thyroidectomy in preventing symptoms related to hypocalcemia. PATIENTS AND METHODS Population Study. This retrospective study was undertaken to evaluate the feasibility of a surgical strategy combining routine autotransplantation of at least 1 parathyroid gland along with routine calcium and vitamin D supplementation during total thyroidectomy in preventing symptoms related to hypocalcemia. The local hospital ethics committee approved database review. An informed consent was obtained from all the patients to review their medical files to be included in the study. All medical records in which total thyroidectomy was performed between January 2000 and June 2005 at our institution were included. Previous thyroid or neck operation or irradiation, concomitant central or lateral neck lymph node dissection, more extensive surgical resection of central compartment viscera such as the larynx, trachea, or esophagus and concomitant parathyroid diseases were exclusion criteria. The following parameters were recorded for all patients: age, sex, preoperative diagnosis, thyroid hormonal status, preoperative and postoperative calcium and phosphorous values, operative time, number of parathyroid gland identified and spared at the operation, the number of autotransplanted parathyroid gland, and final histology. Surgical Technique. All operations were performed by a single surgeon (BA). Iodine-free solutions (chlorehexidine) were used to swab the operative field. Thyroidectomy was performed via a transverse cervicotomy with the patient under general anesthesia. The thyroidectomies were all performed in a similar fashion with careful dissection along the thyroid capsule attempting to identify and preserve the parathyroid glands along with their vascular supply as well as the recurrent laryngeal nerves. When at least 1 parathyroid gland was identified during the operation, further thorough dissection to search for missing glands was avoided. Inadvertently removed parathyroid glands during dissection and/or unequivocally devascularized parathyroid glands were removed and immediately autotransplanted. In the absence of identifiable damaged parathyroid glands, removal of 1 or more parathyroid glands with the most questionable viability was performed for immediate autotransplantation. In those cases of suspected devascularized parathyroid glands, biopsies to confirm or refute viability were avoided. The glands were minced into small (0.5 mm) pieces, and the parathyroid tissue was then immediately autotransplanted into a pocket fashioned in the ipsilateral sternocleidomastoid muscle. The transplantation site was closed with permanent silk suture to prevent graft extrusion and to serve for future identification. Definitive pathologic study was obtained for all resected tissues. Cervical wound was closed without drain tubes. Monitoring of the cervical wound was assessed closely in the postoperative period. Protocol. Treatment was started peroperatively and consisted in administration, by intravenous infusion, of calcium gluconate (1 mequiv/kg/h) Prevention of Hypocalcemia in Thyroidectomy HEAD & NECK DOI /hed September

3 and continued for 24 hours postoperatively. Replacement therapy with oral calcium supplementation (calcium carbonate, g daily) and 1,25-dihydroxyvitamin D3 (Rocaltrol, Roche S.A., Basel, Switzerland), 0.5 to 1 lg daily, was started on the first postoperative day. Calcium supplement and vitamin D analog were gradually decreased and discontinued in the presence of normocalcemia in 2 to 4 weeks. During follow-up, dosage of blood calcium and phosphorous was drawn on the first postoperative day and 4 weeks later, and if this latter dosage was normal, medication was gradually stopped. Otherwise, if hypocalcemia and/or hyperphosphoremia were found, blood parathormone levels were assessed, and the treatment was prolonged accordingly. Postoperative Period and Follow-Up. Postoperative complications, mainly vocal cord paralysis and temporary or permanent hypocalcemia were noted. The presence and the type of hypocalcemia signs were recorded by a surgeon or by a nurse, together with the evaluation of the Chvostek s sign. Biochemical hypocalcemia was defined as serum calcium concentrations less than 2.0 mmol/l on a least 1 postoperative measurement. Postoperative hypocalcemia was defined as patients requiring medications to maintain normocalcemia when they were discharged from the hospital. They were considered as having transient hypocalcemia if they were normocalcemic at least 2 weeks after stopping all medications during follow-up. Postoperative hypocalcemia, requiring treatment to maintain normocalcemia associated with a low parathyroid hormone level (normal: 9 55 pg/ml) more than 1 year postoperatively, was considered as permanent. Discharge from the hospital occurred when the patient was asymptomatic or when the serum calcium level rose above 2 mmol/l. The patients were instructed to contact their physician if symptoms of hypocalcemia developed. Clinical follow-up ranged from 12 to 72 months. Statistical Analysis. Results were expressed as frequencies and percentages for qualitative data and as mean 6 standard deviation or as median with its interquartile range (IQR) for continuous data. The Student s t test and the Mann-Whitney s U tests were used as appropriate (non-normal distribution) to compare continuous data, and chi square statistic was used to compare qualitative data, corrected by the Fischer s exact test as appropriate. A multivariate logistic regression model was used to control for univariate analysis to sort out the adjusted risk factors for postoperative transient hypocalcemia. All tests were 2 sided, and a p value less than.05 was considered statistically significant. All computations were done using SPSS v13 (Chicago, Illinois) statistical software. RESULTS Between January 2000 and June 2005, 286 patients underwent bilateral thyroidectomy with routine autotransplantation of at least 1 parathyroid gland and routine calcium and vitamin D supplementation in our department. Exclusion criteria (34 patients) were as follows: previous thyroid or neck operation or irradiation (n 5 5), concomitant central or lateral neck lymph node dissection (n 5 11), preoperative calcium values below 2 mmol/l (n 5 4), and concomitant parathyroid diseases (n 5 14). There were 38 men and 214 women (252 patients), with a median age of 44 years (IQR, years). Age was similar between both sexes (p 5.97). The thyroid function was normal in 173 patients (68.6%). Hyperthyroidism was exhibited by 76 patients (30.2%), and 3 patients (1.2%) were hypothyroid. All 76 patients with hyperthyroidism were treated with methimazole and b- blocker drug. All had normal thyroid function before the operation. Operative procedures included total lobectomy and isthmusectomy with contralateral near total lobectomy (n 5 137), total thyroidectomy (n 5 93), and bilateral near total thyroidectomy (n 5 22). Operating time was minutes. The indications for operation included multinodular goiter (n 5 143), toxic multinodular goiter (n 5 65), papillary carcinoma documented by preoperative fine-needle aspiration cytology (n 5 16), follicular adenoma (n 5 14), Grave s disease (n 5 11), and Hashimoto thyroiditis with nodules (n 5 3). Substernal thyroid extension was exhibited in 34 patients (13.5%). The weight of resected thyroid tissue varied from 53 to 644 g, with a mean of 83 g. Final pathology showed malignant thyroid neoplasms in 19% of the cases. Numbers of parathyroid glands identified were as follows: 4 in 202 patients, 3 in 41 patients, 2 in 7 patients, and 1 in 2 patients. Immediate parathyroid autotransplantation of 1 to 3 parathyroid glands was performed as follows: 1 in 223 patients, 2 in 27 patients, and 3 in 2 patients. Distribution of transplanted parathyroid glands is depicted in Table 1. Parathyroid autotransplanta Prevention of Hypocalcemia in Thyroidectomy HEAD & NECK DOI /hed September 2008

4 Table 1. Characteristics of transplanted parathyroid glands in 252 patients. Parathyroid gland localization No. of patients Left upper 101 Right upper 98 Right lower 43 Left lower 41 Total 283 tion was performed in apparently healthy parathyroid glands in 219 patients (87%). Postoperatively, 209 patients (83%) were normocalcemic. Postoperative hypocalcemia occurred in 43 patients (17%), of whom 4 patients (1.6%) had symptoms related to hypocalcemia. Clinical manifestations of hypocalcemia were minor in these patients and consisted of rapidly resolving tingling, with no occurrence of any major symptoms such as corporeocaudal spasm or bronchospasm. In our department, the risk of transient hypocalcemia was similar in patients who underwent routine parathyroid autotransplantation with routine calcium and vitamin D compared with those who did not undergo the protocol in our previous study, but the proportion of symptomatic hypocalcemia was lower in the group with vitamin D and calcium supplementation. Hypocalcemia occurred more frequently when 2 or more parathyroid glands were autotransplanted (24 of %,17of275 63%, 2 of % in cases of autotransplantation of 1, 2, or 3 glands, respectively). In univariate analysis, the following factors were associated with transient hypocalcemia: age, thyroid stimulating hormone (TSH) levels, FT4 levels, toxic goiters, number of autotransplanted parathyroid, preoperative, and postoperative day 1 blood calcium level, as shown in Table 2. The male sex, total thyroidectomy, operation for thyroid malignancy, substernal goiter, operative time, weight of resected gland, and length of hospital stay were not statistically linked to transient postoperative hypocalcemia. By subjecting all factors to multivariate logistic regression analysis, postoperative day 1 blood calcium level and number of autotransplanted parathyroids were the only independent predictive factors for the development of transient postoperative hypocalcemia. The postoperative length of stay was 1 day (n patients; 93.6%), 2 days (n 5 11 patients; 4.4%), and more than 2 days (n 5 5 patients; 2%) in relation to the number of parathyroid gland autotransplanted. Asymptomatic hypocalcemic patients were discharged from the hospital the next day after operation. Mean duration of hospitalization for hypocalcemic patients was 3 days, ranging from 2 to 5 days. During follow-up, no patients exhibited clinical symptoms of hypocalcemia, and the blood calcium was normal in all patients at 12 months postoperatively. The incidence of permanent hypoparathyroidism was 0% as certified from blood calcium levels measured at least 6 months postoperatively. Therefore, none of the patients who underwent autotransplantation of at least 1 parathyroid gland required both calcium and vitamin D analog on the long run to maintain a normal calcium level more than 12 months after the operation. Comparing the patients who underwent routine parathyroid autotransplantation with those of our previous series, there was no difference with regard to patients demographics, indications for thyroidectomy (malignant or benign), types of thyroidectomy (total or less than total thyroidectomy, thyroidectomy for substernal, toxic goiters), and weight of thyroid resected specimen. The incidence of postoperative hypocalcemia did not differ Table 2. Significant (p <.05) or near-significant (p <.10) factors associated with transient postoperative hypocalcemia by univariate analysis. Transient postoperative hypocalcemia Factors Yes (n 5 43) No (n 5 209) p value Age, y glands transplanted, no. of patients (%) 19 (44.2) 10 (4.8).00 TSH, miu/ml FT4, ng/dl [M (IQR)]* 1.40 ( ) 1.35 ( ).014 Preoperative Ca, mmol/l Postoperative Day 1 Ca, mmol/l Abbreviations: TSH, thyroid-stimulating hormone; FT4, free thryroxin level; Ca, refers to blood calcium level. Note: Values represent mean 6 standard deviation, except as otherwise stated. M (IQR): Median with its 25% to 75% interquartile range. *The Mann-Witney test was performed because of non-normal distribution. Prevention of Hypocalcemia in Thyroidectomy HEAD & NECK DOI /hed September

5 between the 2 series, that is, 18.6% in the former and 17% in the latter (p 5.28). However, the incidence of symptomatic hypocalcemia was lower in the latter series, decreasing from 4.7% to 1.6% (p 5.05). The incidence of permanent hypoparathyroidism also decreases from 1.9% to 0% (p 5.03). DISCUSSION In this series, routine autotransplantation of at least 1 parathyroid gland during total thyroidectomy reduces to zero the risk of permanent hypoparathyroidism. On the other hand, routine supplementation treatment with oral calcium and vitamin D can effectively prevent symptomatic hypocalcemia after total thyroidectomy with routine parathyroid autotransplantation, allowing a safe early discharge of patients. All patients who were symptomatic experienced only minor tingling that promptly resolved. In most patients, supplementation was discontinued early after the operation, after checking serum calcium concentrations on an outpatient basis. These results on lowering permanent hypoparathyroidism compare favorably with other reported series. A low incidence of permanent hypoparathyroidism has been reported for patients who received parathyroid autotransplantation or for those patients who underwent thyroidectomy with selective parathyroid autotransplantation. 14,16 Zedenius et al 18 reported that routine autotransplantation of at least 1 parathyroid gland during total thyroidectomy may reduce permanent hypoparathyroidism to zero. Paloyan et al 16 reported a decreased incidence of permanent hypoparathyroidism from 3% to 0% when the incidence of parathyroid autotransplantation increased from 25% to 89%. In 1 series, 14 when considering the 216 patients who underwent parathyroid autotransplantation, the incidence of permanent hypoparathyroidism was less than 1%. The practice of implanting parathyroid tissue has a long surgical tradition, but the indication of parathyroid autotransplantation has recently been extended to radical head and neck operations, including total thyroidectomy. 16 In fact, the biochemical function of parathyroid graft can be demonstrated after autotransplantation of normal parathyroid gland and during long-term follow-up. 19,20 In adopting a surgical technique using parathyroid autotransplantation, an operative strategy combining the preservation of parathyroid in situ with selective autotransplantation of resected parathyroid glands has been most commonly used. 14,16 The incidence of parathyroid autotransplantation reported ranges from 19% to 89% for investigators adopting a policy of selective autotransplantation. 14 More liberal or even routine autotransplantation of at least 1 parathyroid gland was recommended during thyroidectomy to avoid permanent hypoparathyroidism. In a retrospective study, 14 a low incidence of permanent hypoparathyroidism was reported in patients who underwent autotransplantation of parathyroid glands. For patients in whom postoperative hypocalcemia developed, those who had received parathyroid autotransplantation, irrespective of the number of parathyroid glands transplanted, had virtually no risk of developing permanent hypoparathyroidism compared with a 26% incidence for patients who did not undergo parathyroid autotransplantation. Because of the favorable outcome in patients who underwent parathyroid autotransplantation, some authors 14 attempted routine autotransplantation of at least 1 parathyroid gland. However, routine parathyroid autotransplantation is associated with a high incidence of postoperative hypocalcemia compared with selective parathyroid autotransplantation, although both approaches can achieve an overall low incidence of permanent hypoparathyroidism. Investigators who adopt selective parathyroid autotransplantation report an incidence of postoperative hypocalcemia requiring treatment in 13% to 54% of patients, 14,16 whereas the incidence increases to 100% for those who adopt routine parathyroid autotransplantation of all identifiable glands. 20 In fact, the frequency of hypocalcemia increased with the number of parathyroid glands resected during thyroidectomy. 16 In adopting a policy of routine parathyroid autotransplantation, patients who underwent parathyroid autotransplantation had a higher incidence of postoperative hypocalcemia compared with those who did not undergo parathyroid autotransplantation. 14 In addition, one would expect operating time to be diminished with routine autotransplantation of parathyroid glands because of the need to recognize 1 parathyroid gland only, avoiding thorough and excessive dissection searching to preserve parathyroid glands. In this series, we adopted routine parathyroid autotransplantation. Multivariate analysis showed that 2 or more parathyroid glands autotransplanted were independent risk factors for postoperative hypocalcemia. Calcium supplementation 1152 Prevention of Hypocalcemia in Thyroidectomy HEAD & NECK DOI /hed September 2008

6 was and should be prescribed as a prophylactic measure for patients who undergo total thyroidectomy in these settings, particularly with 2 or more parathyroid glands autotransplanted, because of an increased risk of postoperative hypocalcemia. A reliable intraoperative method to identify patients with impaired parathyroid function should facilitate the decision to perform parathyroid autotransplantation. Intraoperative parathyroid hormone assay may have a potential role in this application. 8 10,21 In the absence of reliable intraoperative methods to document parathyroid viability or to measure its functional integrity, routine parathyroid autotransplantation stems as a prophylactic measure to protect patients from developing permanent hypoparathyroidism. Once postoperative hypocalcemia develops, early parathyroid function can predict the occurrence of permanent hypopararathyroidism. During the last decade, several authors reported the feasibility and safety of thyroid operation on an outpatient basis. 12,13 However, symptomatic hypocalcemia still represents 1 of the major concerns after total thyroid resection, 10,13 because symptoms occur 24 to 48 hours postoperatively. 12,22,23 Moreover, patterns of patients prone to have this complication, hence requiring oral calcium supplements, vitamin D supplements, or both to avoid symptomatic hypocalcemia 22,24 are unpredictable. Prophylactic infusion of calcium solutions reduces the risk of symptomatic hypocalcemia in patients after total thyroidectomy. 25 The pathogenesis of early hypocalcemia seems multifactorial, whereas surgical technique and surgeons experience play an important role in avoiding permanent hypoparathyroidism after thyroid operation. Monitoring of postoperative serum calcium concentrations is therefore necessary to detect patients who need supplementation therapy. 8,10,11,15,16 Vitamin D administration could raise some concerns about the possible inhibition of parathyroid hormone secretion by normally functioning parathyroid glands. Indeed, it has been demonstrated that oral calcium administration in healthy patients does not decrease the intact parathyroid hormone levels. 1 Oral calcium and vitamin D supplementation do not seem to inhibit the function of normal parathyroid glands. 1 These results could suggest a more extensive and early use of vitamin D in patients with postthyroidectomy hypocalcemia, even though most endocrine surgeons prefer to reserve vitamin D treatment for overt hypoparathyroidism. 2,12,13 One limitation of this series is the absence of a control group with no parathyroid autotransplantation, so that effect of parathyroid autotransplantation during total thyroidectomy could be more precisely assessed. However, showing a statistically significant reduction in the incidence of permanent hypoparathyroidism with different operative strategies may require a prospective randomized trial involving too many patients to be practical because of the low incidence of permanent hypoparathyroidism currently achieved. In conclusion, a low incidence of symptomatic postoperative hypocalcemia and permanent hypoparathyroidism can be achieved by a surgical strategy combining routine oral calcium and vitamin D supplementation and routine autotransplantation of at least 1 parathyroid gland during total thyroidectomy. This combination should be considered during the course of all total thyroidectomies to shorten the length of hospital stay and to reduce the costs and the risk of permanent hypoparathyroidism. REFERENCES 1. Bellantone R, Lombardi CP, Raffaelli M, et al. Is routine supplementation therapy (calcium and vitamin D) useful after total thyroidectomy? Surgery 2002;132: Reeve T, Thompson NW. Complications of thyroid surgery: how to avoid them, how to manage them and observations on their possible effect on the whole patient. World J Surg 2000;24: Pattou F, Combemale F, Fabre S, et al. Hypocalcemia following thyroid surgery: incidence and prediction of outcome. World J Surg 1998;22: Abboud B, Sargi Z, Akkam M, Sleilaty F. Risk factors for postthyroidectomy hypocalcemia. J Am Coll Surg 2002; 195: McHenry CR, Speroff T, Wentworth D, Murphy T. Risk factors for postthyroidectomy hypocalcemia. Surgery 1994;116: Adams J, Andersen P, Everts E, Cohen J. Early postopereative calcium levels as predictors of hypocalcemia. Laryngoscope 1998;108: Wilson RB, Erskine C, Crowe PJ. Hypomagnesemia and hypocalcemia after thyroidectomy: prospective study. World J Surg 2000;24: Moore C, Lampe H, Agrawal S. Predictability of hypocalcemia using early postoperative serum calcium levels. J Otolaryngol 2001;30: Yamashita H, Noguchi S, Murakami T, et al. Predictive risk factors for postoperative tetany in female patients with Graves disease. J Am Coll Surg 2001;192: Luu Q, Andersen PE, Adams J, Wax MK, Cohen JI. The predictive value of perioperative calcium levels after thyroid/parathyroid surgery. Head Neck 2002;24: Moore FD. Oral calcium supplements to enhance early hospital discharge after bilateral surgical treatment of the thyroid gland or exploration of the parathyroid glands. J Am Coll Surg 1994;178: Mowschenson PM, Hodin RA. Outpatient thyroid and parathyroid surgery: a prospective study of feasibility, safety and cost. Surgery 1995;118: Prevention of Hypocalcemia in Thyroidectomy HEAD & NECK DOI /hed September

7 13. McHenry CR. Same-day thyroid surgery: an analysis of safety, cost savings and outcome. Am Surg 1997;63: Lo CY, Lam KY. Routine parathyroid autotransplantation during thyroidectomy. Surgery 2001;129: Walker RP, Paloyan E, Keley TF, Gopalsami C, Jarosz H. Parathyroid autotransplantation in patients undergoing a total thyroidectomy: a review of 261 patients. Otolaryngol Head Neck Surg 1994;111: Olson JA Jr, DeBenedetti MK, Baumann DS, Wells SA Jr. Parathyroid autotransplantation during thyroidectomy. Results of long-tem follow-up. Ann Surg 1996;223: Palazzo FF, Sywak MS, Sidhu SB, Barraclough BH, Delbridge LW. Parathyroid autotransplantation during total thyroidectomy does the number of glands transplanted affect outcome? World J Surg 2005;29: Zedenius J, Wadstrom C, Delbridge L. Routine autotransplantation of at least one parathyroid gland during total thyroidectomy may reduce permanent hypoparathyroidism to zero. Aust NZ J Surg 1999;69: El-Sharaky MI, Kahalil MR, Sharaky O, Sakr MF, Fadaly GA, El-Hamadi HA, Moussa MM. Assessment of parathyroid autotransplantation for preservation of parathyroid function after total thyroidectomy. Head Neck 2003;25: Kikumori T, Imai T, Tanaka Y, Oiwa M, Masc T, Funahashi H. Parathyroid autotransplantation with total thyroidectomy for thyroid carcinoma: long-term follow-up of grafted parathyroid function. Surgery 1999;125: Lam A, Kerr PD. Parathyroid hormone: an early predictor of postthyroidectomy hypocalcemia. Laryngoscope 2003;113: Tartaglia F, Giuliani A, Sgueglia M, Biancari F, Juvonen T, Campana FP. Randomized study on oral administration of calcitriol to prevent symptomatic hypocalcemia after total thyroidectomy. Am J Surg 2005;190: Bove A, Bongarzoni G, Dragani G, et al. Should female patients undergoing parathyroid-sparing total thyroidectomy receive routine prophylaxis for transient hypocalcemia? Am Surg 2004;70: Pisaniello D, Parmeggiani D, Piatto A, et al. Which therapy to prevent post-thyroidectomy hypocalcemia? G Chir 2005;26: Uruno T, Miyauchi A, Shimizu K, et al. A prophylactic infusion of calcium solution reduces the risk of symptomatic hypocalcemia in patients after total thyroidectomy. World J Surg 2006;30: EDITORIAL COMMENT James I. Cohen, MD, PhD Oregon Health and Science University, Portland, Oregon. cohenj@ohsu.edu Ideally, 4 well-vascularized parathyroids would be identified at the conclusion of every total thyroidectomy; however, this is often not the case. Similarly, while assessment of parathyroid viability is relatively straightforward at the extremes of normal color or intense blue venous congestion, more commonly the combination of discoloration from the unavoidable manipulation inherent in parathyroid displacement from the thyroid capsule and blood staining of the surrounding tissue can make this judgment very difficult. What then Correspondence to: J. I. Cohen Head & Neck 30: , 2008 Published online 29 April 2008 in Wiley InterScience ( DOI: /hed VC 2008 Wiley Periodicals, Inc. should the surgeon do with the questionably viable gland? The decision to resect a potentially viable parathyroid gland and autotransplant it is a difficult one, especially if the other glands have not been identified or are similarly discolored; and while the take rate for autotransplanted parathyroid tissue is known to be high, the transplanted tissue can take weeks to months to function, obligating the patient if this is the only remaining parathyroid tissue to a period of calcium/vitamin D supplementation. Furthermore, the evidence that the ultimate function of this tissue is better with autotransplantation than if it is left in situ is inferential at best. As in this manuscript, there is always great difficulty in controlling all of the independent variables that may affect the outcome in the clinical series that have examined this question Prevention of Hypocalcemia in Thyroidectomy HEAD & NECK DOI /hed September 2008

8 Thus, the extension of the thought process described herein, which serves as the conclusion of this manuscript by Abboud et al, namely, that resection and autotransplantation of a normal parathyroid gland will ensure a lower ultimate rate of hypoparathyroidism, requires careful examination before implementation. Although statistical significance was shown, the small number of patients who experienced hypocalcemia limits the statistical power of their conclusion. In addition, the sequential nature of the 2 series before and after the implementation of the routine autotransplantation protocol allows for the possibility that increased surgical experience alone may account for the differences seen. However, this manuscript serves to remind us of the issues involved, that assessment of parathyroid viability is difficult and that parathyroid autotransplantation of obviously and questionably compromised glands should be considered and may improve overall outcome. Further evidence is needed, however, before this concept should be routinely extended to normal parathyroid glands. Prevention of Hypocalcemia in Thyroidectomy HEAD & NECK DOI /hed September