original papers Adv Clin Exp Med 2013, 22, 3, 387–393 ISSN 1899–5276

© Copyright by Wroclaw Medical University

Maciej Bagłaj1, a–d, f, Sylwester Gerus1, b–d, Urszula Dorobisz2, c, e, Tadeusz Łukieńczuk3, c, e, Beata Wikiera4, c, e

Thyroidectomy in Children: Changing Trends and Surgical Strategies Tyreoidektomia u dzieci: zmieniające się trendy epidemiologiczne i strategie postępowania chirurgicznego Department of Pediatric Surgery and Urology, Wroclaw Medical University, Poland Department of Radiology, Wroclaw Medical University, Poland 3 Department of General Surgery, Wroclaw Medical University, Poland 4 Department of Pediatric Endocrinology, Wroclaw Medical University, Poland 1 2

A – research concept and design; B – collection and/or assembly of data; C – data analysis and interpretation; D – writing the article; E – critical revision of the article; F – final approval of article; G – other

Abstract Background. Surgical thyroid pathology is an uncommon problem in children and due to environmental factors may be locally-specific. Until the mid-90’s, Lower Silesia had been regarded as a region of endemic goiter but since then a better system of iodine prophylaxis has been introduced. Objectives. To assess changing trends in the epidemiology of surgical thyroid diseases in children and to examine whether they have influenced potential alterations of operative strategies during the study period. Material and Methods. The medical records of all children operated on for thyroid disease between 1993 and 2010 in the university pediatric surgical center were retrospectively reviewed. The data regarding the indications for thyroidectomy, details of surgical management and outcome were collected and analyzed in three periods of time 1993–1998, 1999–2004 and 2005–2010. Results. There were 46, 63 and 41 children operated on in the analyzed periods of time, respectively, with no significant differences regarding their age and gender. Preoperative thyroid ultrasound scan showed nodular lesions within the thyroid gland in 145 children (94.7%). The frequency of unilateral and bilateral nodular lesions was basically similar throughout the whole study. There has been a significant decrease in subtotal resections from around 63% in the first period to less than 16% in the other two periods of the study. The reverse trend can be clearly seen with regard to unilateral total lobectomy. Since 1999, total lobectomy or total thyroidectomy has been performed in more than 80% of the children. Nodular goiter was the most common indication for surgical operation followed by follicular adenoma. Malignant disease was recorded in 7 children (4.6%). Conclusions. The gradual decrease of the number of children with surgical pathology of the thyroid gland seems to reflect an effective iodine prophylaxis. Depending on the extent of thyroid disease, unilateral lobectomy, either alone or coupled with partial or total resection of the contralateral lobe should be a standard surgical procedure in children (Adv Clin Exp Med 2013, 22, 3, 387–393). Key words: thyroid, children, thyroidectomy, goiter, thyroid nodule.

Streszczenie Wprowadzenie. Chirurgiczne schorzenia tarczycy są rzadkie u dzieci. Na ich występowanie mają wpływ czynniki środowiskowe. Do lat 90. XX  w. Dolny Śląsk był uznawany za obszar endemicznego wola, od tego czasu został jednak wprowadzony lepszy i skuteczniejszy system profilaktyki jodowej. Cel pracy. Ocena zmiennych trendów epidemiologicznych schorzeń chirurgicznych tarczycy u dzieci oraz wykonanie oceny, czy miały one wpływ na zmianę strategii postępowania chirurgicznego. Materiał i metody. Przeprowadzono retrospektywną analizę dokumentacji medycznej dzieci poddanych leczeniu chirurgicznemu w latach 1993–2010 w referencyjnym ośrodku uniwersyteckim chirurgii dziecięcej. Szczegółowej

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ocenie poddano wskazania do zabiegu operacyjnego, szczegóły zabiegu oraz wyniki leczenia. Dane były oceniane i analizowane w trzech okresach: 1993–1998, 1999–2004 i 2005–2010. Wyniki. W analizowanych okresach operowano odpowiednio 46, 63 i 41 dzieci bez istotnych różnic statystycznych w  odniesieniu do wieku i  płci pacjentów. Zmiany guzkowe wykazano na podstawie przedoperacyjnego badania USG u 145 dzieci (94,7%). Częstość występowania zmian obejmujących jeden płat lub oba płaty była zbliżona we wszystkich analizowanych okresach badawczych. Odsetek resekcji subtotalnych bardzo wyraźnie zmniejszył się z 63% w pierwszym okresie do mniej niż 16% w trzecim okresie. Odwrotny trend obserwowano w odniesieniu do jednostronnego usunięcia płata tarczycy. Od 1999 roku całkowite usunięcie co najmniej jednego płata było wykonane u ponad 80% dzieci. Najczęstszym wskazaniem do leczenia chirurgicznego było wole guzkowe oraz gruczolak pęcherzykowy. Nowotwory złośliwe odnotowano tylko u 7 dzieci (4,6%). Wnioski. Stopniowe zmniejszanie częstości występowania schorzeń tarczycy leczonych chirurgicznie u  dzieci wydaje się wynikać ze skuteczniejszego programu profilaktyki jodowej na terenie Dolnego Śląska. Jednostronna totalna lobektomia uzupełniona o częściowe lub całkowite wycięcie drugiego płata powinna być przyjęta jako standardowy zabieg chirurgiczny u dziecka ze schorzeniem chirurgicznym tarczycy (Adv Clin Exp Med 2013, 22, 3, 387–393). Słowa kluczowe: tarczyca, dzieci, tyreoidektomia, wole, wole guzkowe.

Surgical thyroid diseases are relatively uncommon in children. Although the indications for their operative management are predominantly based on a higher risk of malignancy in this age group, strategies applied by pediatric surgeons frequently follow those used in adult patients. A unique feature of thyroid pathology is the fact that due to environmental factors it may be locally-specific. Iodine deficiency must be numbered as one of the most important factors involved in the etiology of diseases of the thyroid gland in the pediatric population [1, 2]. Until the mid-90’s, Lower Silesia had been regarded as a region of endemic goiter. Since then an effective system of iodine prophylaxis has been introduced in Poland [3]. Taking these facts into consideration, the authors have undertaken a  18-year retrospective review of their experience with thyroidectomy in children. The authors specifically aimed to assess changing trends in the epidemiology of surgical thyroid diseases in children from Lower Silesia and to examine whether they have influenced potential alterations of operative strategies during the study period.

Material and Methods The medical files of all children who underwent operative treatment due to disease of the thyroid gland between 1993 and 2010 at the University Department of Pediatric Surgery in Wroclaw were selected from the hospital database and subjected to a  detailed analysis. The Department of Pediatric Surgery is the only center offering an operative management of thyroid pathology in children in the south-west region of Poland, which has more than 3.5  million inhabitants. All of the children were referred to the surgical department by a pediatric endocrinologist. Preoperative diagnosis included hormonal studies, ultrasound scan of the thyroid gland and fine-needle aspiration

biopsy in all patients. Thyroid scintigraphy was part of the routine work-up during the first years of the study period. Later it was ordered routinely in the cases presenting with hyperthyreosis only. Indications for an operative procedure were established by an endocrinologist and surgeon together. During the first two years of the study period, the operative procedures were performed by or under supervision of the surgeon from the Department of General Surgery of the Wroclaw Medical University. Since 1995 all operative procedures have been performed by the senior author (MB). The data regarding the patients’ demographics, previous medical history, clinical presentation of thyroid disease, and the results of hormonal and imaging studies were selected and analyzed in all patients. The details of the surgical procedure were extracted from the operative notes. Three basic categories of thyroidectomy were arbitrarily accepted for the purpose of this study, namely: partial, subtotal and total resection, each referring either to one lobe or to the entire gland. In each case the final diagnosis was made by the pathologist examining the resected specimen. In order to comply with the principal aim of the retrospective study, all data was analyzed separately in the three 6-year consecutive periods; 1993–1998, 1999–2004 and 2005–2010. Statistical significance between frequencies was calculated by the chi-square test χ2df with Yate’s correction with a corresponding degree of freedom df (df = (m–1)*(n–1), where m – number of rows, n  –  number of columns) or if the expected value was less than 5, by a Fisher exact test (F). A p  value of less than 0.05 was required to reject the null hypothesis. Statistical analysis was performed using the EPIINFO Ver. 3.5.2 software package (CDC, Atlanta, Georgia, USA).

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Thyroidectomy in Children Table 1. Pathological anatomy of the thyroid gland assessed on the preoperative ultrasound scan

Tabela 1. Zmiany anatomiczne gruczołu tarczowego ocenione na podstawie przedoperacyjnego badania ultrasonograficznego Years (Lata)

Total (Ogółem)

Only one lobe affected (Tylko w jednym płacie)

Both lobes affected (Zmiany w obu płatach)

Diffuse (Zmiany rozsiane)

single lesion (pojedyncza zmiana)

multiple lesions (mnogie zmiany)

single lesion (pojedyncza zmiana)

multiple lesions (mnogie zmiany)

single lesion (pojedyncza zmiana)

multiple lesions (mnogie zmiany)

enlargement (powiększenie)

1993–1998

46

18 (39.1%)

8 (17.4%)

2 (4.3%)

–

12 (26%)

6 (13%)

1999–2004

63

29 (46%)

9 (14.2%)

7 (11.1%)

4 (6.3%)

12 (19%)

2 (3.1%)

2005–2010

41

16 (39%)

3 (7.3%)

6 (14.6%)

5 (12.2%)

11 (25.6%)

– 

Table 2. Surgical procedures performed in the analyzed periods of time (sub – subtotal, part – partial, tot – total lobectomy) Tabela 2. Rodzaj leczenia operacyjnego u dzieci w analizowanych okresach (sub – subototalna resekcja, part – częściowa resekcja plata, tot – calkowite usunięcie płata) Years (Lata)

Procedure (lobe/lobe) (Typ zabiegu (płat/płat)) sub/sub

sub/–

sub/part

part/part

part/–

tot/–

tot/tot

tot/sub

tot/part

1993–1998

21

2

6

2

–

4

4

7

– 

N = 46

45.6%

4.3%

13.04%

4.3%

8.7%

8.7%

15.2%

1999–2004

7

–

4

1

31

6

9

5

N = 63

11.1%

6.3%

1.6%

49.2%

9.5%

14.3%

7.9%

2005–2010

4

2

–

3

14

6

3

9

N = 41

9.7%

7.3%

34.1%

14.6%

7.3%

21.9%

–

4.9%

Results One hundred and fifty children constituted the study group. Their age ranged from 7 to 18  years (mean 14.8). Three children were operated on twice because of the recurrence of nodular goiter after initial subtotal resection and therefore the total number of operations was 153. There were 116  girls (77.3%). The incidence of surgical thyroid disease among boys in the analyzed periods was 19.6%, 25.3% and 22.5% respectively (p > 0.05). There were no statistical differences when the mean age of the patients in each study period was studied. Preoperative thyroid ultrasound showed nodular lesions within the thyroid gland in 145  children (94.7%). In 8 children the thyroid gland showed diffuse enlargement of both lobes. Table 1 illustrates the distribution of pathological lesions of the gland in the analyzed patients when assessed by preoperative ultrasound scan. Comparing all three studied periods, two trends could be detected, namely decreasing number of children with diffuse enlargement of the thyroid gland and slowly increasing incidence of thyroid disease affecting both lobes. Only when

–

comparing the first and the third period were the differences statistically significant, with a p-value of 0.0172 and x = 13.8. One hundred eleven children (74%) were euthyroid on initial presentation. In thirty-three children (22%) hormonal studies revealed hyperthyroid status. Only six children (4%) suffered from hypothyroidism. When this data is analyzed in the three periods of study, the incidence of euthyroid patients rose from 63% to 76.2% between 1999 and 2004 and up to 87.7%. The distribution of patients with hyperthyroidism was 37.2%, 18.75% and 12.2%, respectively. In Table 2, surgical procedures were summarized in the three studied periods. During the first years, subtotal resection of the thyroid gland was the preferable operative option regardless of the extension of thyroid disease. This was the principle applied by the adult surgeons supervising the first procedures performed in the clinic. It had been followed by the authors until around 1998 unless there were indications for another type of thyroid resection. During this period, thyroid scintigraphy was a routine preoperative study. The

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rence of nodular disease prompted total left lobectomy six years later. The second patient had right total and left partial lobectomy in 2001 due to a large single nodule in each lobe. In 2009 she had the left lobe totally excised because of recurrence of the disease with multiple nodules within the residual thyroid tissue. The last patient had a single large nodule in the left lobe and multiple smaller nodular lesions within the right lobe and subsequently had a total left lobectomy and partial excision of the right lobe. Pathology revealed follicular adenoma and nodular goiter. Due to recurrence of multiple nodules in the right lobe, it was subsequently excised in 2008. The results of pathological examination of the resected specimens of the thyroid gland are presented in Table 3. They include 3 specimens from the re-operated children as well. Statistical analysis did not reveal any significant trend with regards to incidence of particular pathology throughout of the study period.

lobe containing cold nodules was routinely sent for intraoperative pathological assessment (frozen section). Most children operated in the first 2 periods of the study had preoperative fine needle thyroid biopsy performed in the local hospital either by the radiologist or attending pathologist. In cases of suspicion of malignant disease, unilateral lobectomy with intraoperative pathology was an initial operative step. Total thyroidectomy was indicated in children with confirmed malignancy. Unfortunately, in 3 of the first 5  patients with thyroid carcinoma, the initial cytology was negative and all had subtotal resection of the thyroid gland. These patients underwent reoperation within two weeks of the primary operative procedure with completion of total thyroidectomy and modified bilateral cervical lymphadenectomy. Papillary carcinoma, follicular carcinoma and medullar carcinoma were finally diagnosed in these cases respectively. Since 1999, all patients in whom FNB revealed suspicious cells or raised suspicion of follicular lesion underwent at least unilateral lobectomy. Such strategy was subsequently transferred for patients with unilateral pathology of the thyroid gland, even in cases of benign preoperative cytology. Statistical analysis has revealed significant differences between the first and other two periods of the study with regard to subtotal and total procedures (p