Table of Contents  

Ahmad, Kutaiman, Hassan, Amin, and Khan: Complication rates of thyroidectomy by an experienced, high-volume thyroid surgeon in a private hospital in Abu Dhabi, United Arab Emirates

Introduction

Disorders of the thyroid gland are very common in the general population and thyroidectomy is one of the most common endocrine surgical procedures. Theodor Kocher was the first to describe thyroidectomy scientifically, decreasing morbidity and mortality rates, and clinical outcomes continue to improve as technical understanding increases.13

Thyroidectomy is performed by a variety of surgeons, including general, endocrine, ear, nose and throat (ENT), and head and neck surgeons.2 The extent of resection ranges from lobectomy to total thyroidectomy.4 Despite improved techniques and a greater understanding of the procedure, thyroidectomy continues to carry significant risk of morbidity and mortality. Complications range from minor to life-threatening and can be transient or permanent.1,2,57 The two major complications are laryngeal nerve palsy and hypocalcaemia (hypoparathyroidism). The reported incidence of permanent laryngeal nerve palsy ranges from 0% to 18.6%, while the incidence of temporary laryngeal nerve palsy ranges from 1.4% to 38%. The corresponding figures for hypocalcaemia are 1.2–11%1,7,8 and 1–40%, respectively.1,5,9

Various factors have been shown to affect the occurrence of complications, such as the extent of resection, surgeon experience and volume, surgical technique, redo surgery and the nature and type of thyroid disease.2,5,6,8 It has been shown that experienced, high-volume surgeons have superior outcomes to inexperienced, low-volume surgeons owing to improved techniques developed and refined over time.2,4,68,10 Surgeons are defined as high volume if they perform > 100 cases per year, intermediate if they perform 10–100 cases per year and low volume if they perform < 10 cases per year.11

The objective of this study was to determine the overall rate of complication of thyroidectomy by a high-volume surgeon with > 10 years’ experience and a special interest in thyroid surgery, and to achieve a permanent complication rate of 0%. We analysed the impact of various factors on complication rates, such as patient age, sex, type of thyroidectomy, type of goitre and goitre pathology (malignant or benign), and toxicity.

Materials and methods

This prospective study was conducted in the General Surgery Department of Mediclinic Al-noor Hospital, Abu Dhabi, United Arab Emirates, between January 2013 and May 2015 and involved 228 patients. Sample size was calculated using an 18.5% incidence rate of postoperative thyroidectomy complication,7 a 95% significance level and a 5% margin of error. All patients aged > 13 years who presented with goitres were included, irrespective of patient sex, goitre size and whether the goitre was malignant or benign, toxic or non-toxic or a multinodular goitre (MNG), solitary thyroid nodule (STN) or diffuse. Patients with osteoporosis, concomitant hyperparathyroidism or clinically enlarged neck nodes that required neck dissection were excluded.

All patients were assessed in outpatient clinics by thorough clinical examination, blood test, imaging of the neck and fine-needle aspiration cytology. Patients were evaluated preoperatively by anaesthetists, endocrinologists and ENT surgeons for vocal cord functions, and by other specialists as required. Patients with hyperthyroidism were made clinically and biochemically euthyroid before surgery. All operations were performed by the same consultant surgeon, who had > 10 years’ experience in thyroid surgery. Surgeries were performed using standard open thyroidectomy techniques: capsular dissection and the use of ligatures for tying vascular pedicles. Every attempt was made to save the parathyroid glands by ligating the individual branches of the inferior thyroid artery to keep its vascularity; if parathyroid glands were accidentally removed, these were reimplanted into the sternomastoid muscle.

We did not perform extensive exploration for recurrent laryngeal nerve (RLN) identification except in patients with very large, difficult goitres in whom there was a high risk of nerve injury owing to its displaced position; rather, we avoided the nerve by performing capsular dissection. This strategy was adopted to decrease the likelihood of transient RLN injury or dysfunction by excessive manipulation. Every patient was left with a suction drain in their thyroid bed. The vocal cords of all patients were examined for mobility by an anaesthetist at the time of extubation.

Serum calcium was measured in all patients on the morning after surgery, or earlier if the patient developed symptoms of hypocalcaemia; during follow-up visits patients were examined for bleeding, changes to their voice and wound infection. Patients with a serum calcium concentration of < 8.4 mg/dl were considered hypocalcaemic and treated with either oral or intravenous therapy depending on their serum calcium level and symptoms. Patients with impaired vocal cord mobility and marked hoarseness were considered to have an RLN injury. All patients were followed up in the outpatient clinic after 3 days, 1 week and 4 weeks. Patients with hypocalcaemia and RLN injury were followed up at 6 months. If they had recovered fully before 6 months, the complications were defined as transient; otherwise they were defined as permanent.

The data were entered and analysed using SPSS version 13.0 (IBM, Armonk, NY, USA). Frequencies and percentages were calculated and a chi-squared test was used to identify factors that significantly affected complications, using a 95% significance level and a 5% margin of error. A P-value of < 0.05 was considered significant.

Results

A total of 228 patients were included: 61.8% were aged < 46 years, the majority (74.6%) were female, 80.3% had benign goitres and the most commonly performed operation was total thyroidectomy (Table 1).

TABLE 1

Demographic data and statistics

Characteristic Number of patients (%)
Age (years)
 < 46 141 (61.8)
 ≥ 46 87 (38.2)
Sex
 Male 58 (25.4)
 Female 170 (74.6)
Goitre pathology
 Benign 183 (80.3)
 Malignant 45 (19.7)
Goitre type
 STN 15 (6.6)
 MNG 213 (93.4)
Goitre toxicity
 Toxic 29 (12.7)
 Non-toxic 199 (87.3)
Procedure
 Completion/redo 4 (1.7)
 Total thyroidectomy 207 (90.8)
 Lobectomy/hemithyroidectomy 17 (7.5)
 Subtotal thyroidectomy 0 (0)
 Near-total thyroidectomy 0 (0)

The overall complication rate was 16.23%, with no permanent complications. Transient postoperative hypocalcaemia was the most frequent complication, present in 15.8% of cases. We did not encounter any cases of RLN injury or wound infection. Post-operative bleeding occurred in only one patient (Table 2). There was no statistically significant effect of goitre type, pathology, toxicity or type of thyroidectomy on the rate of hypocalcaemia (Table 3). Hyperthyroidism had a statistically significant effect on postoperative bleeding (P = 0.008) (Table 4).

TABLE 2

Frequency of complications

Complication Number of patients (%)
Hypocalcaemia
 Transient 36 (15.8)
 Permanent 0 (0)
 No 192 (84.2)
Bleeding
 Yes 1 (0.4)
 No 227 (99.6)
Recurrent laryngeal nerve injury
 Yes 0 (0)
 No 228 (100)
Infection
 Yes 0 (0)
 No 228 (100)
Total complication
 Yes 37 (16.23)
 No 191 (83.77)
TABLE 3

Impact of various factors on hypocalcaemia

Characteristics Hypocalcaemia, n (%) P-value
Yes No
Age (years) 0.397
 < 46 20 (14.2) 121 (85.8)
 ≥ 46 16 (18.4) 71 (81.6)
Sex 0.629
 Male 8 (13.8) 50 (86.2)
 Female 28 (16.5) 142 (83.5)
Goitre pathology 0.961
 Benign 29 (15.8) 154 (84.2)
 Malignant 7 (15.6) 38 (84.4)
Goitre type 0.787
 STN 2 (13.3) 13 (86.7)
 MNG 34 (16.0) 179 (84.0)
Goitre toxicity 0.818
 Toxic 5 (17.2) 24 (82.8)
 Non-toxic 31 (15.6) 168 (84.4)
Procedure 0.114
 Completion/redo 0 (0) 4 (100)
 Total thyroidectomy 36 (17.4) 171 (82.6)
 Lobectomy/hemithyroidectomy 0 (0) 17 (100)
TABLE 4

Impact of various factors on postoperative bleeding

Characteristics Bleeding, n (%) P-value
Yes No
Age (years) 0.431
 < 46 1 (7) 140 (99.3)
 ≥ 46 0 (0) 87 (100)
Sex 0.086
 Male 1 (1.7) 57 (98.3)
 Female 0 (0) 170 (100)
Goitre pathology 0.619
 Benign 1 (0.5) 182 (99.5)
 Malignant 0 (0) 45 (100)
Goitre type 0.790
 STN 0 (0) 15 (100)
 MNG 1 (0.5) 212 (99.5)
Goitre toxicity 0.008
 Toxic 1 (3.4) 28 (96.6)
 Non-toxic 0 (0) 199 (100)
Procedure 0.95
 Completion/redo 0 (0) 4 (100)
 Total thyroidectomy 1 (0.5) 206 (99.5)
 Lobectomy/hemithyroidectomy 0 (0) 17 (100)

Discussion

Today thyroidectomy is considered a very safe procedure, but it is not entirely free from complications. Some of the immediate complications are life-threatening if not recognized and treated promptly, whereas others, such as hypocalcaemia and RLN injury, add significant morbidity, particularly if they are permanent. Various factors influence the occurrence of these complications, such as extent of resection, operating surgeon’s experience, volume and size of goitre, and goitre pathology and toxicity. The majority of these complications can be minimized or prevented if performed by an experienced, high-volume surgeon with a special interest in thyroid surgery.2,3,8,10

The overall rate of complication in this study was 16.23%, and all complications were transient. The rates of post-thyroidectomy complication reported in the literature vary widely. Although some authors have reported a lower overall rate of complication than in this study, all have reported permanent complications; there was not one case of permanent complication in this study.2,8,12 On the other hand, we report a lower rate of complication than many other studies in the literature.3,5,7,13 No transient complications in this study adversely affect the quality of life of patients, who were free from symptoms 1 week after surgery.

The most common postoperative complication of thyroidectomy is hypocalcaemia, which may be symptomatic or asymptomatic. Hypocalcaemia is most commonly caused by postoperative parathyroid insufficiency due to incidental removal of one or more glands, stunning and devascularization of the glands. However, transient postoperative hypocalcaemia can be caused by haemodilution, increased urinary excretion due to surgical stress, calcitonin release and hungry bone syndrome in patients with hyperthyroidism.1417 In this study, the rate of hypocalcaemia was 15.8%. None of those hypocalcaemic patients required calcium supplements after 2 weeks. Some authors have reported a lower incidence of postoperative hypocalcaemia than we report in this study (as low as 3.5%),2,7,17 whereas several other studies have reported a higher incidence of hypocalcaemia (as high as 59%).4,13,14,16 The majority of studies with lower rates have encountered some form of permanent hypoparathyroidism (hypocalcaemia), which greatly impairs the patient’s quality of life. In comparison, we did not encounter any permanent hypocalcaemia. All patients with transient hypocalcaemia did not require calcium supplements after 2 weeks. The overall incidence in this study is on the lower side of the reported data in the literature; more significantly, we have achieved the lowest possible rate of permanent hypocalcaemia.4,5,9,12,14

We looked at the impact of various other factors such as age, sex, type and extent of thyroidectomy, type of goitre, and goitre pathology and toxicity. None of these was found to have a statistically significant effect on the rate of hypocalcaemia, similar to findings reported in the majority of studies.7,17,18 Few studies have reported statistically significant effects of the type of thyroidectomy, toxic MNG, malignant goitres, age and female sex on postoperative hypocalcaemia; however, these findings have not been reported together in any individual study but scattered across multiple studies.7,17

One of most the serious complications of thyroidectomy is RLN injury because it adds significant disability, particularly in its permanent form. None of our patients experienced RLN injury, whether transient or permanent. The incidence of RLN injury reported in the literature varies from 2% to 17%.2,4,7,19,20 Some studies report no permanent RLN injury but occasional transient RLN injury.21,22 Thyroid surgeons have differing views on how to prevent RLN injury: some recommend direct visualization of the RLN or intraoperative nerve monitoring to reduce the risk of permanent RLN injury,9,20,23 while others recommend avoiding the routine exploration of the RLN as this increases the incidence of transient RLN injury.19,23 We believe that the 0% rate of RLN injury achieved can be attributed to two factors: the surgical technique employed and the large number of procedures performed by the operating surgeon. We did not explore the RLN extensively in easy and small goitres with intact tissue planes and more predictable course of the nerve in small goitres; we avoided the nerve to minimize temporary RLN injury. However, we explored and identified the nerve in more difficult cases, such as large goitres, tissue planes distorted by inflammation in thyroiditis, infiltrating malignant goitres and redo cases, in which the nerve is usually displaced or incorporated into the inflamed tissue, resulting in a high risk of transection causing permanent damage.4,7,8,10,19,23

On the basis of these observations, and in contrast to the majority of studies, we do not recommend the avoidance of routine identification of the RLN during thyroidectomy. However, we attribute the absence of any type of RLN injury in this study to the experience of the high-volume surgeon, who employed both techniques preferentially: identifying the RLN in some cases and avoiding it in others. In order to recommend against routine identification of the RLN, large and long-term studies are required.

Postoperative bleeding is one of the most life-threatening complications of thyroidectomy. Only one of our patients developed postoperative bleeding (0.4%), which was detected early because of an unusual increase in the output of the suction drain. This was re-explored immediately, a small haematoma was found and a small bleeding vessel was ligated; the patient’s condition was not compromised. Our rate of postoperative bleeding is well within the incidence range reported in the international literature of 0% to 5%;2 a recent American study reported an incidence of 2.3%.24 We observed a statistically significant effect of toxic MNG on the rate of postoperative bleeding. Zambudio et al.7 have observed similar effects on postoperative bleeding from hyperthyroidism (toxicity). The single case of postoperative bleeding in this study was observed in a young man with a long-standing toxic MNG; although he was made euthyroid before surgery, toxic goitres retain their increased vascularity and are prone to postoperative bleeding.7

In this study we did not use any prophylactic antibiotics beyond strictly observing the standard sterile precautions in the perioperative period. Our rate of postoperative wound infection was 0%. In the literature the incidence of wound infection has been reported as up to 2%.2,22

Conclusion

The rate of complication of thyroidectomy can be significantly reduced, and the rate of permanent complication reduced to 0%, if performed by an experienced, high-volume surgeon with a special interest in thyroid surgery.

References

1. 

Terrell A, Gardner P, Spanos WC, et al. Clinical outcomes of a team approach to thyroidectomy. S D Med 2015; 68:539–41.

2. 

Khanzada TW, Samad A, Memon W, Kumar B. Post thyroidectomy complications: the Hyderabad experience. J Ayub Med Coll Abbottabad 2010; 22:65–8.

3. 

Richmond BK, Eads K, Flaherty S, Belcher M, Runyon D. Complications of thyroidectomy and parathyroidectomy in the rural community hospital setting. Am Surg 2007; 73:332–6.

4. 

Kotan C, Kösem M, Algün E, Ayakta H, Sönmez R, Söylemez O. Influence of the refinement of surgical technique and surgeon’s experience on the rate of complications after total thyroidectomy for benign thyroid disease. Acta Chir Belg 2003; 103:278–81. http://dx.doi.org/10.1080/00015458.2003.11679423

5. 

Neto ME, TagliariniI JV, López BE et al. Factors influencing thyroidectomy complications. Braz J Otorhinolaryngol 2012; 78:63–9. http://dx.doi.org/10.1590/S1808-86942012000300012

6. 

Hassan-Smith ZK, Gopinath P, Mihaimeed F. A UK-wide survey of life-threatening thyroidectomy complications. J Thyroid Res 2011; 2011:329620. https://doi.org/10.4061/2011/329620

7. 

Zambudio AR, Rodríguez J, Riquelme J, Soria T, Canteras M, Parrilla P. Prospective study of postoperative complications after total thyroidectomy for multinodular goiters by surgeons with experience in endocrine surgery. Ann Surg 2004; 240:18–25. https://doi.org/10.1097/01.sla.0000129357.58265.3c

8. 

Sosa JA, Bowman HM, Tielsch JM, Powe NR, Gordon TA, Udelsman R. The importance of surgeon experience for clinical and economic outcomes from thyroidectomy. Ann Surg 1998; 228:320–30. https://doi.org/10.1097/00000658-199809000-00005

9. 

Bhattacharyya N, Fried MP. Assessment of the morbidity and complications of total thyroidectomy. Arch Otolaryngol Head Neck Surg 2002; 128:389–92. https://doi.org/10.1001/archotol.128.4.389

10. 

Adam M, Thomas SM, Roman SA, Sosa JA. Is there a minimum case volume of thyroidectomies associated with superior outcomes? An analysis of 37,118 cases in the US. J Am Coll Surg 2015; 221:S60–1. http://dx.doi.org/10.1016/j.jamcollsurg.2015.07.132

11. 

Kandil E, Noureldine SI, Abbas A, Tufano RP. The impact of surgical volume on patient outcomes following thyroid surgery. J Surg 2013; 154:1346–52. http://dx.doi.org/10.1016/j.surg.2013.04.068

12. 

Chang LY, O’Neill C, Suliburk J, Sidhu S, Delbridge L, Sywak M. Sutureless total thyroidectomy: a safe and cost-effective alternative. J Surg 2011; 81:510–14. https://doi.org/10.1111/j.1445-2197.2010.05492.x

13. 

Lee YS, Nam KH, Chung WY, Chang HS, Park CS. Postoperative complications of thyroid cancer in a single center experience. J Korean Med Sci 2010; 25:541–5. http://dx.doi.org/10.3346/jkms.2010.25.4.541

14. 

Iqbal M, Subhan A, Baig MS, Shah MS. Frequency of hypocalcaemia in total thyroidectomy. J Surg Pak 2010; 15:87–91.

15. 

Wu J, Harrison B. Hypocalcemia after thyroidectomy: the need for improved definitions. World J End Surg 2010; 2:17–20. https://doi.org/10.5005/jp-journals-10002-1015

16. 

Kumar S, Patel SM, Pandey R, Jain SK. Hypocalcaemia in total thyroidectomy: a hospital based study. Int J Sci Stud 2014; 2:21–4.

17. 

Baldassarre RL, Chang DC, Brumund KT, Bouvet M. Predictors of hypocalcemia after thyroidectomy: results from the nationwide inpatient sample. ISRN Surg 2012; 2012:838614. http://dx.doi.org/10.5402/2012/838614

18. 

Merchavy S, Marom T, Forest VI, et al. Comparison of the incidence of postoperative hypocalcemia following total thyroidectomy vs completion thyroidectomy. Otolaryngol Head Neck Surg 2015; 152:53–6. http://dx.doi.org/10.1177/0194599814556250

19. 

Zakaria HM, Al Awad NA, Al Kreedes AS, et al. Recurrent laryngeal nerve injury in thyroid surgery. Oman Med J 2011; 26:34–8. https://doi.org/10.5001/omj.2011.09

20. 

Ardito Gl, Revelli L, D’Alatri L, Lerro V, Guidi ML, Ardito F. Revisited anatomy of the recurrent laryngeal nerve. Am J Surg 2007; 187:249–53. https://doi.org/10.1016/j.amjsurg.2003.11.001

21. 

Idris SA, Ali QM, Hamza AA. Incidence of recurrent laryngeal nerves injury during thyroid surgery. Sch J App Med Sci 2013; 1:673–6.

22. 

Dionigi Gl, Boni L, Rovera F, Bacuzzi A, Dionigi R. Neuromonitoring and video-assisted thyroidectomy: a prospective, randomized case control evaluation. Surg Endosc 2009; 23:996–1003. https://doi.org/10.1007/s00464-008-0098-3

23. 

Acun Z1, Cinar F, Cihan A, et al. Importance of identifying the course of the recurrent laryngeal nerve in total and near-total thyroid lobectomies. Am Surg 2005; 71:225–7.

24. 

Samona S, Hagglund K, Edhayan E. Case cohort study of risk factors for post-thyroidectomy hemorrhage. Am J Surg 2016; 211:537–40. https://doi.org/10.1016/j.amjsurg.2015.10.023




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