- Email: [email protected]
Surgical complications after thyroid surgery performed in a cancer hospital
Surgical complications after thyroid surgery performed in a cancer hospital JOÃO GONÇALVES FILHO,
MD,
and LUIZ PAULO KOWALSKI,
MD, PHD,
São Paulo, Brazil
OBJECTIVE: This study evaluates the incidence and risk factors of complications in patients submitted to thyroidectomy in a cancer hospital with residency training. STUDY DESIGN: A retrospective chart and complications review of 1020 patients (1990-2000) underwent to thyroidectomy. RESULTS: At our cancer hospital, 1020 patients underwent thyroidectomy. The main postoperative complications consisted of transient hypocalcemia in 134 (13.1%) patients, permanent hypocalcemia in 26 (2.5%) patients, transient vocal cord palsy in 14 (1.4%) patients, and permanent vocal cord palsy in 4 (0.4%) patients. The type of thyroidectomy, neck dissection, and paratracheal lymph node dissection were significantly associated with transitory and permanent hypocalcemia. CONCLUSION: Thyroid surgery can be performed safely in a surgical residency training program under direct supervision of an experienced surgeon with little morbidity to the patients. Hypocalcemia is the most significant complication. Neck and paratracheal lymph node dissections were the most significant predictors of hypocalcemia in patients who underwent total thyroidectomy. (Otolaryngol Head Neck Surg 2005;132:490-4.)
differentiated cancer. Undifferentiated carcinomas are usually not resectable.1,5-8 The type of thyroidectomy depends on the benign or malignant characteristics of the lesion, size of the nodule(s), and extent to which the gland is affected. In differentiated thyroid cancer, the type of surgery used (lobectomy with isthmusectomy or total thyroidectomy) depends on the prognostic factors.1,9 A unilateral or a bilateral paratracheal dissection is usually performed in patients with differentiated carcinoma. At the beginning of the 20th century, the major complications of thyroidectomy were hematoma and postoperative infection, and most publications reported some postoperative mortality.8,10,11 Currently, the main postoperative complications are vocal cord palsy due to dysfunction of the recurrent laryngeal nerve and hypocalcemia. Postoperative death is rare or even unrecorded.3,8,10-13 The incidence and severity of complications are linked to the experience of the surgical team and the extent of the operation.11,14 The main purpose of this article is to evaluate the incidence and risk factors of complications in patients undergoing thyroidectomy in a cancer hospital with a surgical residency training program, with a view to propose preventive measures that can result in reduction of costs, period of hospitalization, as well as improvements in the patient=s quality of life.
T hyroidectomy is one of the main forms of treatment
PATIENTS AND METHODS Between January 1990 and December 2000, 1020 patients underwent thyroidectomy in the Head and Neck Surgery and Otorhinolaryngology Department of the Centro de Tratamento e Pesquisa Hospital do Câncer A C Camargo, in São Paulo, Brazil. There were 888 (87%) female patients and 132 (13%) male patients, with a mean age of 46 years (range, 2 to 88 years). Preoperative evaluation included clinical history and physical examination, thyroid function tests, and radiography of the thorax. All patients had preoperative evaluation of vocal cord mobility by means of indirect laryngoscopy. The indication for thyroidectomy included 702 (69%) benign thyroid diseases and 318 (31%) malignant tumors. Most surgeries were performed by 3rd to 5th year residents under the supervision of 10 different head and neck surgeons. Surgeons were stratified according to the total number of thyroidectomies they performed or supervised during the study period: Group
for thyroid gland diseases. The incidence of palpable thyroid nodules varies from 4% to 7% in the U. S. adult population.1 In cases of uni- or multinodular goiter, the indications for surgical treatment are: the presence of obstructive symptoms, cosmetic problems (size of the goiter), hyperthyroidism, and any clinical suspicion of malignant neoplasia.2-4 Thyroidectomy is indicated in the treatment of all patients with primary malignant From the Head and Neck Surgery and Otorhinolaryngology Department, Centro de Tratamento e Pesquisa Hospital do Câncer A C Camargo, São Paulo, Brazil. Reprint requests: Luiz Paulo Kowalski, MD, PhD, Head and Neck Surgery and Otorhinolaryngology Department, Centro de Tratamento e Pesquisa Hospital do Câncer A C Camargo, Rua Professor Antonio Prudente, 211, 01509900, São Paulo, Brazil; e-mail: [email protected]. 0194-5998/$30.00 Copyright © 2005 by the American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. doi:10.1016/j.otohns.2004.09.028
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A (1 to 50 thyroidectomies), group B (50 to 100), and group C (over 100). We routinely identified the parathyroids and recurrent laryngeal nerves before performing the ligation of the inferior thyroid pedicles. An autotransplant of the parathyroid in the sternocleiodomastoid or anterior scalene muscle was performed every time there was vascular supply injury or the glands were accidentally removed. The use of surgical drains varied throughout the study period. Penrose drains were used initially, but it was replaced in 1992 by Hemovac closed drainage to facilitate postoperative care and permit earlier discharge from the hospital. Since 1995, at the surgeon’s discretion, the operative wounds of 178 selected patients were not drained. Drains were not used in 138 patients undergoing lobectomy with isthmusectomy, in 14 lobectomy, in 8 subtotal thyroidectomy, in 13 partial lobectomy, and 5 completion of thyroidectomy. All patients were evaluated with regard to the occurrence of postoperative complications. We routinely performed indirect laryngoscopy or nasofibroscopy before the 30th postoperative day. Recurrent laryngeal nerve dysfunction, hypoparathyroidism, and other complications are analyzed according to the number of operations, type of thyroidectomy, and whether or not drains were used. Postoperative vocal cord palsy was defined as the presence of immobility or decreased movement of the vocal cords. A persisting vocal cord dysfunction after 6 months was considered permanent. Palsies that resulted from inferior laryngeal nerve resection due to neoplastic involvement were considered as sequelae and not computed as complications. Hypocalcemia was considered whenever there was a need for exogenous calcium replacement in order to maintain normal serum levels (8 to 10.4 mg/dL) or to eliminate the clinical signs and symptoms of hypocalcemia. Hypocalcemia was considered permanent when calcium replacement was necessary for over 6 months. The association between the studied variables with the occurrence of complications was evaluated by the Chi-square test, or Fisher’s exact test when applicable. Values of P ⬍ 0.05 were considered significant. RESULTS One thousand twenty thyroidectomies were performed during the study period. There were 295 total thyroidectomies, 436 lobectomies with isthmusectomy, 75 unilateral lobectomies, 73 reoperative thyroid resections (completion of thyroidectomy), 114 subtotal thyroidectomies, and 27 partial lobectomies. Ipsilateral neck dissection was performed in 50 patients (6 jugular chain dissections, 38 type III modified radical dissections, and 6 classical radical neck dissections). Bilateral neck dissections were performed in 12 patients (3 bi-
FILHO and KOWALSKI 491
Table 1. Post-thyroidectomy complications Complications
Procedures (N) (%)
THypo.* PHypo.† TVC palsy‡ PVC palsy§ Hematoma Seroma Surgical site infection THypo ⫹ TVC palsy‡ THypo. ⫹ Seroma THypo. ⫹ Surgical site infection THypo. ⫹ chyle leaks PHypo. ⫹ Surgical site infection Hematoma ⫹ Seroma Seroma ⫹ Surgical site infection THypo. ⫹ TVC palsy ⫹ Hematoma THypo. ⫹ TVC palsy ⫹ Seroma
119 (11.7) 25 (2.5) 7 (0.7) 4 (0.4) 7 (0.7) 31 (3.0) 12 (1.2) 5 (0.5) 4 (0.4) 2 (0.2) 2 (0.2) 1 (0.1) 1 (0.1) 1 (0.1) 1 (0.1) 1 (0.1)
*Transitory hypocalcemia. †Permanent hypocalcemia. ‡Transient vocal cord palsy. §Permanent vocal cord palsy.
lateral jugular chain dissections, 8 bilateral type III modified radical dissections, and 1 type III ipsilateral radical neck dissections with contralateral jugular chain dissection). Paratracheal lymph node dissection was performed in 128 patients (63 ipsilateral and 65 bilateral). Thyroidectomy was performed or supervised by surgeons classified according to the number of thyroidectomies: 3% in group A, 27.3% in group B, and 69.7% in group C. The mean duration of hospital stay was 2 days (range, 2 to 30) for the 702 patients with benign tumors and 3 days (range, 2 to 19) for the 318 patients with a malignant tumor. However, complications were most significantly associated with thyroidectomy performed for the treatment of malignant disease (P ⬍ 0.05), with hypocalcemia as the most frequent complication. Other less frequent complications were vocal cord palsy, hematoma, seroma, and surgical site infection (Table 1). The overall rate of vocal cord palsy was 1.8% (Table 2). Transitory palsy occurred in 14 patients with full recovery occurring within 6 months. Four patients had permanent vocal cord palsy. There were no bilateral palsies nor was there a need for tracheotomy. The type of thyroidectomy, the surgeon’s experience, patient’s gender, diameter of the nodule, and the association or not with neck dissection did not have any significant association with the incidence of vocal cord palsy. Postoperative hypocalcemia occurred in 15.6% patients (Table 2). Permanent hypocalcemia occurred in 26 patients (2.5%) and transitory hypocalcemia was found in 134 (13.1%) patients. The rates of postopera-
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492 FILHO and KOWALSKI
Table 2. Extent of thyroidectomy and complications Hypocalcemia Trans*
VC palsy‡ Perm†
Trans*
Perm†
Thyroidectomy
N
ⴙ
%
ⴙ
%
ⴙ
%
ⴙ
%
Partial lobectomy Unilateral lobectomy Lobect. ⫹ Istm.§ Subtotal Reoperation Total Total of cases
27 75 436 114 73 295 1020
0 0 0 4 18 112 134
0 0 0 3.5 24.7 38 13.1
0 0 0 0 5 20 26
0 0 0 0 6.8 6.8 2.5
0 0 2 2 1 9 14
0 0 0.5 1.8 1.4 3.1 1.4
0 0 2 1 0 1 4
0 0 0.5 0.9 0 0.3 0.4
*Transient. †Permanent. ‡Vocal cord palsy. §Lobectomy with isthmusectomy.
tive hypocalcemia was higher after total thyroidectomy as compared with other procedures (Table 2). Temporary hypocalcemia was significantly associated with total thyroidectomy (P ⫽ 0.021) and paratracheal lymph node dissection (P ⫽ 0.017). In the same way, neck dissection was significantly associated with permanent hypocalcemia (0.033) (Table 3). There were no significant associations among surgeons classified per number of thyroidectomies performed or supervised and temporary or permanent hypocalcemia rates. Similarly, there was no significant association of hypocalcemia with gender or nodule diameter (Table 3). Seroma was a postoperative complication found in 38 (3.7%) patients. Seroma developed in 8 (3.6%) of 222 patients drained with a Penrose drain , 22 (3.5%) of the 622 drained with Hemovac, and 8 (4.5%) of the 178 patients in whom no drain was placed. Sixteen (1.6%) patients developed postoperative surgical site infections. Nine (0.9%) patients were reoperated on as a result of a hematoma. Chyle leaks occurred in 2 (0.2%) patients undergoing neck dissection. No significant differences were observed between these complications and the presence of drain, type of thyroidectomy, and number of thyroidectomies performed or supervised by the surgeon (P ⬎ 0.05). DISCUSSION Thyroidectomy is a very common therapeutic procedure worldwide and is performed by surgeons with varied training and backgrounds: general surgery, thoracic surgery, endocrine surgery, otolaryngologic surgery, oncologic surgery, and head and neck surgery. The Head and Neck Surgery and Otorhinolaryngology Department of the Centro de Tratamento e Pesquisa Hospital do Câncer A C Camargo is part of a surgical oncology training program, where the greater part of
such operations are performed by 3rd to 5th year residents in surgical oncology or head and neck surgery fellows under the direct supervision of a head and neck surgeon. Although some reports11,14 in the literature relate the complications of this operation directly to the surgeon’s experience, there are also several reports3,4,11,15-17 that point out the safety of this operation performed at residency training centers, with acceptable complication rates, when performed under the supervision of an experienced surgeon. In our study, 69.7% of the thyroidectomies were performed by 4 surgeons, 27.3% by 3 surgeons, and 3% by 3 surgeons. However, no statistically significant differences were observed between the groups. These results differ from other reports possibly because it is a single institution experience. All the members of the staff have similar backgrounds and the junior assistants are constantly supervised by more experienced surgeons. Similarly, Bergamaschi et al,18 in a series of 1192 thyroidectomies performed by 11 surgeons, also did not observe significant differences between patient volume per surgeons and the complication rates. There has been a significant reduction in the incidence of complications and mortality in thyroid surgery since the beginning of the 20th century, currently making thyroidectomy a surgical procedure with low acceptable morbidity and mortality rates. Postoperative mortality with thyroidectomy has become an extremely unusual complication.4-7,10,13,14,19,20 Postoperative death was also not observed in our series. Pederson et al15 had 0.4% deaths and HerranzGonzalez et al,21 in a series of 335 thyroidectomies, observed a mortality rate of 0.8%. The rates of postoperative complications reported in literature are variable (7.4% to 53%).3-5,10,15 In our series, we observed postoperative
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FILHO and KOWALSKI 493
Table 3. Hypocalcemia after total and reoperative thyroidectomy according to clinical variables Hypocalcemia (%) Variable Gender Male Female Nodule (cm) ⱕ4 ⬎4 Surgeon group A B C Thyroidectomy Total Re-operation Neck dissection No Unilateral Bilateral Paratracheal dissection No Unilateral Bilateral
No
Transient
P
Permanent
P
59 309
17 (28.8) 113 (36.6)
0.253
3 (5.1) 22 (7.1)
0.569
220 148
83 (37.7) 47 (31.8)
0.240
12 (5.5) 13 (8.8)
0.213
13 111 244
3 (23.1) 38 (34.2) 89 (1.6)
0.591
2 (15.4) 5 (4.5) 18 (0.6)
0.277
295 73
112 (38) 18 (24.7)
0.021
20 (6.8) 5 (6.8)
0.577
306 50 12
105 (34.3) 23 (46) 2 (16.7)
0.087
18 (5.9) 4 (8.2) 3 (25)
0.033
247 55 66
75 (30.4) 25 (45.5) 30 (45.5)
0.017
13 (5.3) 4 (7.3) 2 (2.9)
0.143
complications in 226 (22.2%) patients, the most frequently found complication being hypocalcemia. The most common and feared complications in thyroid gland surgery are vocal cord palsy and hypocalcemia, and there are various factors involved in their occurrence.4,5,10,18,21-23 The incidence of recurrent laryngeal nerve injury found in literature vary from 0% to 4.8%,3,4,15,17,19,21 and are greater in extensive resections and in the cases of reoperation.5,6,8,13,20 In our series, only 4 patients (0.4%) showed permanent vocal cord palsy. We observed that the patients with transitory vocal palsy presented recovery of the normal vocal cord mobility within 6 months. The patients who remained with vocal cord palsy for more than 6 months continued after 1 year of follow-up without improvement in the vocal cord mobility. Two patients showed an improvement in the dysphonia for discrete hoarseness and 2 other patients evolved with moderate hoarseness. Pezzullo et al8 found permanent vocal cord palsy in 2.8% of the cases. Chao et al20 observed a 2.6% incidence of transitory palsy and a 1.7% rate of permanent vocal cord palsy in cases of reoperation for benign and malignant neoplasias. In our group, the dissection and identification of the recurrent laryngeal nerve is performed as a routine manner before the ligation of the inferior pedicle vessels, thus reducing the risk of nerve injury. This early identification of the recurrent laryngeal nerve is also advocated by several other authors.3,11,13 Hypocalcemia was an important complication in our series (13.1% transitory and 2.5% permanent). On re-
viewing recent thyroidectomy literature, we found an incidence of symptomatic postoperative hypocalcemia ranging from 4% to 42%.3,5,6,10,15,18,21,23 In this series, all the patients with transitory hypocalcemia were treated with oral calcium or vitamin D analog supplementation for a period of 1 to 6 months. However, all the patients that needed supplementation for more than 6 months presented permanent hypocalcemia. In the same way, in 1998, Lo et al24 reported in their series that of 35 patients with transitory hypocalcemia only 3 (8.5%) patients needed a calcium supplement after 6 months. In the same year, Pattou et al25 in a prospective study observed that all patients with transitory hypocalcemia became normocalcemic within 1 week to 6 months after thyroidectomy. Permanent hypocalcemia occurs with a lower incidence (0% to 8%).3,4,7,10,11,15,21,23 Neck dissection and paratracheal dissection (ipsilateral or bilateral) were the most important risk factors for the occurrence of hypocalcemia. Paratracheal dissection has been implicated in the increase of the risk of both vocal cord palsy and postoperative hypocalcemia.3,8,21 In view of the results of this study, we conclude that thyroidectomy, whether or not associated with neck dissection, is an operation that has low morbidity with hypocalcemia as the most important postoperative complication. Paratracheal lymph node dissection was the most significant predictor of hypocalcemia in patients who underwent total thyroidectomy. Thyroidectomy may be safely performed in resident training
494 FILHO and KOWALSKI
centers, provided that it is performed under the supervision of an experienced surgeon. REFERENCES 1. Shah JP. Thyroid and parathyroids. In: Shah JP, editor. Head and neck surgery, 1st ed. New York: Mosby-Wolfe;1996. p. 393-429. 2. Sternes HF, Brooks DC, Pinkus GS. Surgery for thyroid carcinoma. Cancer 1985;55:1376-81. 3. Shindo LM, Sinha UK, Rice DH. Safety of thyroidectomy in residency: a review of 186 consecutive cases. Laryngoscope 1995;105:1173-5. 4. Calik A, Kucuktulu U, Ciel A, et al. Complications of 867 thyroidectomies performed in a region of endemic goiter in turkey. Int Surg 1996;81:298-301. 5. Thompson NW, Harness J.K. Complications of total thyroidectomy for carcinoma. Surg Gynecol Obstet 1970;131:861-8. 6. Flynn MB, Lyons KJ, Tarter JW, et al. Local complications after surgical resection for thyroid carcinoma. Am J Surg 1994;168: 404-7. 7. Sand J, Palkola K, Salmi J. Surgical complications after total thyroidectomy and resections for differentiated thyroid carcinoma. Ann Chir Gynaecol 1996;85:305-8. 8. Pezzulo L, Dalrio P, Losito NS, et al. Post-operative complications after completion thyroidectomy for differentiated thyroid cancer. Eur J Surg Oncol 1997;123:215-8. 9. Shaha AR, Shah JP, Loree TR. Patterns of failure in differentiated carcinoma of the thyroid based on risk groups. Head Neck 1998;20:26-30. 10. Moulton-Barrett R, Crumley R, Jalilie S, et al. Complications of thyroid surgery. Int Surg 1997;82:63-6. 11. Shaha A, Jaffe BM. Complications of thyroid surgery performed by residents. Surgery 1988;104:1109-14.
Otolaryngology– Head and Neck Surgery March 2005
12. Wax KM, Valiulis AP, Hurst MK. Drains in thyroid and parathyroid surgery. Arch Otolaryngol Head Neck Surg 1995;121:981-3. 13. Al-Suliman NN, Ryttov NF, Blichert-Toft M, et al. Experience in a specialist thyroid surgery unit: a demographic study, surgical complications, and outcome. Eur J Surg 1997;163:13-20. 14. Sosa JA, Bowman HM, Tielsch JM, et al. The importance of surgeon experience for clinical and economic outcomes from thyroidectomy. Ann Surg 1998;228:320-30. 15. Pederson WC, Johson CL, Gaskill HV, et al. Operative management of thyroid disease. Am J Surg 1984;148:350-2. 16. Roy van Zuidewijn DBW, Songun I, Kievit J, et al. Complications of thyroid surgery. Ann Surg Oncol 1995;2:56-60. 17. Lamade W, Renz K, Klar E, et al. Effect of training on the incidence of nerve damage in thyroid surgery. Br J Surg 1999; 86:388-91. 18. Bergamaschi R, Becouarn G, Ronceray J, et al. Morbidity of thyroid surgery. Am J Surg 1998;176:71-5. 19. Jacobs JK, Aland JW, Jr , Ballinger JF. Total thyroidectomy: a review of 213 patients. Ann Surg 1983;197:542-7. 20. Chao TC, Jeng LB, Lin JD, et al. Reoperative thyroid surgery. World J Surg 1997;21:644-7. 21. Herranz-Gonzalez J, Gavilan J, Matinez-Vidal J, et al. Complications following thyroid surgery. Arch Otolaryngol Head Neck Surg 1991;117:516-8. 22. Lore JM Jr. Surgery of the thyroid gland. Otolaryngol Clin North Am 1980;13:69-83. 23. Wingert DJ, Friesen SR, Iliopoulos JI, et al. Post-thyroidectomy hypocalcemia. Am J Surg 1986;152:606-9. 24. Lo C-Y, Lam K-Y. Postoperative hypocalcemia in patients who did or did not undergo parathyroid autotransplantation during thyroidectomy: a comparative study. Surgery 1998;124:1081-7. 25. Pattou F, Comemale F, Fabre S, et al. Hypocalcemia following thyroid surgery: incidence and prediction of outcome. World J Surg 1998;22:718-24.
MD,
and LUIZ PAULO KOWALSKI,
MD, PHD,
São Paulo, Brazil
OBJECTIVE: This study evaluates the incidence and risk factors of complications in patients submitted to thyroidectomy in a cancer hospital with residency training. STUDY DESIGN: A retrospective chart and complications review of 1020 patients (1990-2000) underwent to thyroidectomy. RESULTS: At our cancer hospital, 1020 patients underwent thyroidectomy. The main postoperative complications consisted of transient hypocalcemia in 134 (13.1%) patients, permanent hypocalcemia in 26 (2.5%) patients, transient vocal cord palsy in 14 (1.4%) patients, and permanent vocal cord palsy in 4 (0.4%) patients. The type of thyroidectomy, neck dissection, and paratracheal lymph node dissection were significantly associated with transitory and permanent hypocalcemia. CONCLUSION: Thyroid surgery can be performed safely in a surgical residency training program under direct supervision of an experienced surgeon with little morbidity to the patients. Hypocalcemia is the most significant complication. Neck and paratracheal lymph node dissections were the most significant predictors of hypocalcemia in patients who underwent total thyroidectomy. (Otolaryngol Head Neck Surg 2005;132:490-4.)
differentiated cancer. Undifferentiated carcinomas are usually not resectable.1,5-8 The type of thyroidectomy depends on the benign or malignant characteristics of the lesion, size of the nodule(s), and extent to which the gland is affected. In differentiated thyroid cancer, the type of surgery used (lobectomy with isthmusectomy or total thyroidectomy) depends on the prognostic factors.1,9 A unilateral or a bilateral paratracheal dissection is usually performed in patients with differentiated carcinoma. At the beginning of the 20th century, the major complications of thyroidectomy were hematoma and postoperative infection, and most publications reported some postoperative mortality.8,10,11 Currently, the main postoperative complications are vocal cord palsy due to dysfunction of the recurrent laryngeal nerve and hypocalcemia. Postoperative death is rare or even unrecorded.3,8,10-13 The incidence and severity of complications are linked to the experience of the surgical team and the extent of the operation.11,14 The main purpose of this article is to evaluate the incidence and risk factors of complications in patients undergoing thyroidectomy in a cancer hospital with a surgical residency training program, with a view to propose preventive measures that can result in reduction of costs, period of hospitalization, as well as improvements in the patient=s quality of life.
T hyroidectomy is one of the main forms of treatment
PATIENTS AND METHODS Between January 1990 and December 2000, 1020 patients underwent thyroidectomy in the Head and Neck Surgery and Otorhinolaryngology Department of the Centro de Tratamento e Pesquisa Hospital do Câncer A C Camargo, in São Paulo, Brazil. There were 888 (87%) female patients and 132 (13%) male patients, with a mean age of 46 years (range, 2 to 88 years). Preoperative evaluation included clinical history and physical examination, thyroid function tests, and radiography of the thorax. All patients had preoperative evaluation of vocal cord mobility by means of indirect laryngoscopy. The indication for thyroidectomy included 702 (69%) benign thyroid diseases and 318 (31%) malignant tumors. Most surgeries were performed by 3rd to 5th year residents under the supervision of 10 different head and neck surgeons. Surgeons were stratified according to the total number of thyroidectomies they performed or supervised during the study period: Group
for thyroid gland diseases. The incidence of palpable thyroid nodules varies from 4% to 7% in the U. S. adult population.1 In cases of uni- or multinodular goiter, the indications for surgical treatment are: the presence of obstructive symptoms, cosmetic problems (size of the goiter), hyperthyroidism, and any clinical suspicion of malignant neoplasia.2-4 Thyroidectomy is indicated in the treatment of all patients with primary malignant From the Head and Neck Surgery and Otorhinolaryngology Department, Centro de Tratamento e Pesquisa Hospital do Câncer A C Camargo, São Paulo, Brazil. Reprint requests: Luiz Paulo Kowalski, MD, PhD, Head and Neck Surgery and Otorhinolaryngology Department, Centro de Tratamento e Pesquisa Hospital do Câncer A C Camargo, Rua Professor Antonio Prudente, 211, 01509900, São Paulo, Brazil; e-mail: [email protected]. 0194-5998/$30.00 Copyright © 2005 by the American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. doi:10.1016/j.otohns.2004.09.028
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Otolaryngology– Head and Neck Surgery Volume 132 Number 3
A (1 to 50 thyroidectomies), group B (50 to 100), and group C (over 100). We routinely identified the parathyroids and recurrent laryngeal nerves before performing the ligation of the inferior thyroid pedicles. An autotransplant of the parathyroid in the sternocleiodomastoid or anterior scalene muscle was performed every time there was vascular supply injury or the glands were accidentally removed. The use of surgical drains varied throughout the study period. Penrose drains were used initially, but it was replaced in 1992 by Hemovac closed drainage to facilitate postoperative care and permit earlier discharge from the hospital. Since 1995, at the surgeon’s discretion, the operative wounds of 178 selected patients were not drained. Drains were not used in 138 patients undergoing lobectomy with isthmusectomy, in 14 lobectomy, in 8 subtotal thyroidectomy, in 13 partial lobectomy, and 5 completion of thyroidectomy. All patients were evaluated with regard to the occurrence of postoperative complications. We routinely performed indirect laryngoscopy or nasofibroscopy before the 30th postoperative day. Recurrent laryngeal nerve dysfunction, hypoparathyroidism, and other complications are analyzed according to the number of operations, type of thyroidectomy, and whether or not drains were used. Postoperative vocal cord palsy was defined as the presence of immobility or decreased movement of the vocal cords. A persisting vocal cord dysfunction after 6 months was considered permanent. Palsies that resulted from inferior laryngeal nerve resection due to neoplastic involvement were considered as sequelae and not computed as complications. Hypocalcemia was considered whenever there was a need for exogenous calcium replacement in order to maintain normal serum levels (8 to 10.4 mg/dL) or to eliminate the clinical signs and symptoms of hypocalcemia. Hypocalcemia was considered permanent when calcium replacement was necessary for over 6 months. The association between the studied variables with the occurrence of complications was evaluated by the Chi-square test, or Fisher’s exact test when applicable. Values of P ⬍ 0.05 were considered significant. RESULTS One thousand twenty thyroidectomies were performed during the study period. There were 295 total thyroidectomies, 436 lobectomies with isthmusectomy, 75 unilateral lobectomies, 73 reoperative thyroid resections (completion of thyroidectomy), 114 subtotal thyroidectomies, and 27 partial lobectomies. Ipsilateral neck dissection was performed in 50 patients (6 jugular chain dissections, 38 type III modified radical dissections, and 6 classical radical neck dissections). Bilateral neck dissections were performed in 12 patients (3 bi-
FILHO and KOWALSKI 491
Table 1. Post-thyroidectomy complications Complications
Procedures (N) (%)
THypo.* PHypo.† TVC palsy‡ PVC palsy§ Hematoma Seroma Surgical site infection THypo ⫹ TVC palsy‡ THypo. ⫹ Seroma THypo. ⫹ Surgical site infection THypo. ⫹ chyle leaks PHypo. ⫹ Surgical site infection Hematoma ⫹ Seroma Seroma ⫹ Surgical site infection THypo. ⫹ TVC palsy ⫹ Hematoma THypo. ⫹ TVC palsy ⫹ Seroma
119 (11.7) 25 (2.5) 7 (0.7) 4 (0.4) 7 (0.7) 31 (3.0) 12 (1.2) 5 (0.5) 4 (0.4) 2 (0.2) 2 (0.2) 1 (0.1) 1 (0.1) 1 (0.1) 1 (0.1) 1 (0.1)
*Transitory hypocalcemia. †Permanent hypocalcemia. ‡Transient vocal cord palsy. §Permanent vocal cord palsy.
lateral jugular chain dissections, 8 bilateral type III modified radical dissections, and 1 type III ipsilateral radical neck dissections with contralateral jugular chain dissection). Paratracheal lymph node dissection was performed in 128 patients (63 ipsilateral and 65 bilateral). Thyroidectomy was performed or supervised by surgeons classified according to the number of thyroidectomies: 3% in group A, 27.3% in group B, and 69.7% in group C. The mean duration of hospital stay was 2 days (range, 2 to 30) for the 702 patients with benign tumors and 3 days (range, 2 to 19) for the 318 patients with a malignant tumor. However, complications were most significantly associated with thyroidectomy performed for the treatment of malignant disease (P ⬍ 0.05), with hypocalcemia as the most frequent complication. Other less frequent complications were vocal cord palsy, hematoma, seroma, and surgical site infection (Table 1). The overall rate of vocal cord palsy was 1.8% (Table 2). Transitory palsy occurred in 14 patients with full recovery occurring within 6 months. Four patients had permanent vocal cord palsy. There were no bilateral palsies nor was there a need for tracheotomy. The type of thyroidectomy, the surgeon’s experience, patient’s gender, diameter of the nodule, and the association or not with neck dissection did not have any significant association with the incidence of vocal cord palsy. Postoperative hypocalcemia occurred in 15.6% patients (Table 2). Permanent hypocalcemia occurred in 26 patients (2.5%) and transitory hypocalcemia was found in 134 (13.1%) patients. The rates of postopera-
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492 FILHO and KOWALSKI
Table 2. Extent of thyroidectomy and complications Hypocalcemia Trans*
VC palsy‡ Perm†
Trans*
Perm†
Thyroidectomy
N
ⴙ
%
ⴙ
%
ⴙ
%
ⴙ
%
Partial lobectomy Unilateral lobectomy Lobect. ⫹ Istm.§ Subtotal Reoperation Total Total of cases
27 75 436 114 73 295 1020
0 0 0 4 18 112 134
0 0 0 3.5 24.7 38 13.1
0 0 0 0 5 20 26
0 0 0 0 6.8 6.8 2.5
0 0 2 2 1 9 14
0 0 0.5 1.8 1.4 3.1 1.4
0 0 2 1 0 1 4
0 0 0.5 0.9 0 0.3 0.4
*Transient. †Permanent. ‡Vocal cord palsy. §Lobectomy with isthmusectomy.
tive hypocalcemia was higher after total thyroidectomy as compared with other procedures (Table 2). Temporary hypocalcemia was significantly associated with total thyroidectomy (P ⫽ 0.021) and paratracheal lymph node dissection (P ⫽ 0.017). In the same way, neck dissection was significantly associated with permanent hypocalcemia (0.033) (Table 3). There were no significant associations among surgeons classified per number of thyroidectomies performed or supervised and temporary or permanent hypocalcemia rates. Similarly, there was no significant association of hypocalcemia with gender or nodule diameter (Table 3). Seroma was a postoperative complication found in 38 (3.7%) patients. Seroma developed in 8 (3.6%) of 222 patients drained with a Penrose drain , 22 (3.5%) of the 622 drained with Hemovac, and 8 (4.5%) of the 178 patients in whom no drain was placed. Sixteen (1.6%) patients developed postoperative surgical site infections. Nine (0.9%) patients were reoperated on as a result of a hematoma. Chyle leaks occurred in 2 (0.2%) patients undergoing neck dissection. No significant differences were observed between these complications and the presence of drain, type of thyroidectomy, and number of thyroidectomies performed or supervised by the surgeon (P ⬎ 0.05). DISCUSSION Thyroidectomy is a very common therapeutic procedure worldwide and is performed by surgeons with varied training and backgrounds: general surgery, thoracic surgery, endocrine surgery, otolaryngologic surgery, oncologic surgery, and head and neck surgery. The Head and Neck Surgery and Otorhinolaryngology Department of the Centro de Tratamento e Pesquisa Hospital do Câncer A C Camargo is part of a surgical oncology training program, where the greater part of
such operations are performed by 3rd to 5th year residents in surgical oncology or head and neck surgery fellows under the direct supervision of a head and neck surgeon. Although some reports11,14 in the literature relate the complications of this operation directly to the surgeon’s experience, there are also several reports3,4,11,15-17 that point out the safety of this operation performed at residency training centers, with acceptable complication rates, when performed under the supervision of an experienced surgeon. In our study, 69.7% of the thyroidectomies were performed by 4 surgeons, 27.3% by 3 surgeons, and 3% by 3 surgeons. However, no statistically significant differences were observed between the groups. These results differ from other reports possibly because it is a single institution experience. All the members of the staff have similar backgrounds and the junior assistants are constantly supervised by more experienced surgeons. Similarly, Bergamaschi et al,18 in a series of 1192 thyroidectomies performed by 11 surgeons, also did not observe significant differences between patient volume per surgeons and the complication rates. There has been a significant reduction in the incidence of complications and mortality in thyroid surgery since the beginning of the 20th century, currently making thyroidectomy a surgical procedure with low acceptable morbidity and mortality rates. Postoperative mortality with thyroidectomy has become an extremely unusual complication.4-7,10,13,14,19,20 Postoperative death was also not observed in our series. Pederson et al15 had 0.4% deaths and HerranzGonzalez et al,21 in a series of 335 thyroidectomies, observed a mortality rate of 0.8%. The rates of postoperative complications reported in literature are variable (7.4% to 53%).3-5,10,15 In our series, we observed postoperative
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Table 3. Hypocalcemia after total and reoperative thyroidectomy according to clinical variables Hypocalcemia (%) Variable Gender Male Female Nodule (cm) ⱕ4 ⬎4 Surgeon group A B C Thyroidectomy Total Re-operation Neck dissection No Unilateral Bilateral Paratracheal dissection No Unilateral Bilateral
No
Transient
P
Permanent
P
59 309
17 (28.8) 113 (36.6)
0.253
3 (5.1) 22 (7.1)
0.569
220 148
83 (37.7) 47 (31.8)
0.240
12 (5.5) 13 (8.8)
0.213
13 111 244
3 (23.1) 38 (34.2) 89 (1.6)
0.591
2 (15.4) 5 (4.5) 18 (0.6)
0.277
295 73
112 (38) 18 (24.7)
0.021
20 (6.8) 5 (6.8)
0.577
306 50 12
105 (34.3) 23 (46) 2 (16.7)
0.087
18 (5.9) 4 (8.2) 3 (25)
0.033
247 55 66
75 (30.4) 25 (45.5) 30 (45.5)
0.017
13 (5.3) 4 (7.3) 2 (2.9)
0.143
complications in 226 (22.2%) patients, the most frequently found complication being hypocalcemia. The most common and feared complications in thyroid gland surgery are vocal cord palsy and hypocalcemia, and there are various factors involved in their occurrence.4,5,10,18,21-23 The incidence of recurrent laryngeal nerve injury found in literature vary from 0% to 4.8%,3,4,15,17,19,21 and are greater in extensive resections and in the cases of reoperation.5,6,8,13,20 In our series, only 4 patients (0.4%) showed permanent vocal cord palsy. We observed that the patients with transitory vocal palsy presented recovery of the normal vocal cord mobility within 6 months. The patients who remained with vocal cord palsy for more than 6 months continued after 1 year of follow-up without improvement in the vocal cord mobility. Two patients showed an improvement in the dysphonia for discrete hoarseness and 2 other patients evolved with moderate hoarseness. Pezzullo et al8 found permanent vocal cord palsy in 2.8% of the cases. Chao et al20 observed a 2.6% incidence of transitory palsy and a 1.7% rate of permanent vocal cord palsy in cases of reoperation for benign and malignant neoplasias. In our group, the dissection and identification of the recurrent laryngeal nerve is performed as a routine manner before the ligation of the inferior pedicle vessels, thus reducing the risk of nerve injury. This early identification of the recurrent laryngeal nerve is also advocated by several other authors.3,11,13 Hypocalcemia was an important complication in our series (13.1% transitory and 2.5% permanent). On re-
viewing recent thyroidectomy literature, we found an incidence of symptomatic postoperative hypocalcemia ranging from 4% to 42%.3,5,6,10,15,18,21,23 In this series, all the patients with transitory hypocalcemia were treated with oral calcium or vitamin D analog supplementation for a period of 1 to 6 months. However, all the patients that needed supplementation for more than 6 months presented permanent hypocalcemia. In the same way, in 1998, Lo et al24 reported in their series that of 35 patients with transitory hypocalcemia only 3 (8.5%) patients needed a calcium supplement after 6 months. In the same year, Pattou et al25 in a prospective study observed that all patients with transitory hypocalcemia became normocalcemic within 1 week to 6 months after thyroidectomy. Permanent hypocalcemia occurs with a lower incidence (0% to 8%).3,4,7,10,11,15,21,23 Neck dissection and paratracheal dissection (ipsilateral or bilateral) were the most important risk factors for the occurrence of hypocalcemia. Paratracheal dissection has been implicated in the increase of the risk of both vocal cord palsy and postoperative hypocalcemia.3,8,21 In view of the results of this study, we conclude that thyroidectomy, whether or not associated with neck dissection, is an operation that has low morbidity with hypocalcemia as the most important postoperative complication. Paratracheal lymph node dissection was the most significant predictor of hypocalcemia in patients who underwent total thyroidectomy. Thyroidectomy may be safely performed in resident training
494 FILHO and KOWALSKI
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