Enis Yetkin

The recurrent laryngeal nerve and the inferior thyroid artery--anatomical variations during surgery.

Background and aimsRecognition of variations of the inferior laryngeal nerve is essential. We aimed to investigate the relationship of the inferior laryngeal nerve with the inferior thyroid artery.Materials and methodsA study was undertaken between August 2005 and August 2006. A total of 253 adult patients undergoing thyroid surgery were included in this prospective, non-randomized study. Both sides of the thyroid gland were considered separately.ResultsSixteen variations of the nerve were clarified. In the most observed variation, the nerve was deep to the artery. Two and three nervous branches were seen in 22.5% and 1.6% of the patients, respectively. Bifurcation of the nerve was mostly observed on the left side. No non-recurrent laryngeal nerve was found.ConclusionTo avoid the risk of nerve damage during thyroid surgery, a good knowledge of the variations of the inferior laryngeal nerve is essential. This is important to achieve an undisturbed quality of life for the thyroid patient.

The Interaction of Oxidative Stress Response with Cytokines in the Thyrotoxic Rat: Is There a Link?

Oxidative stress is regarded as a pathogenic factor in hyperthyroidism. Our purpose was to determine the relationship between the oxidative stress and the inflammatory cytokines and to investigate how melatonin affects oxidative damage and cytokine response in thyrotoxic rats. Twenty-one rats were divided into three groups. Group A served as negative controls. Group B had untreated thyrotoxicosis, and Group C received melatonin. Serum malondialdehyde (MDA), glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPx), and nitric oxide derivates (NO•x), and plasma IL-6, IL-10, and TNF-alpha were measured. MDA, GSH, NO•x, IL-10, and TNF-alpha levels increased after L-thyroxine induction. An inhibition of triiodothyronine and thyroxine was detected, as a result of melatonin administration. MDA, GSH, and NO•x levels were also affected by melatonin. Lowest TNF-alpha levels were observed in Group C. This study demonstrates that oxidative stress is related to cytokine response in the thyrotoxic rat. Melatonin treatment suppresses the hyperthyroidism-induced oxidative damage as well as TNF-alpha response.

The role of allopurinol on oxidative stress in experimental hyperthyroidism

Aim: During hyperthyroidism, production of free oxygen radicals derives, where xanthine oxidase may also play an important role. Allopurinol, a xanthine oxidase inhibitor, has a significant effect on thyrotoxicosis-related oxidative stress. However, the relationship between thyroid hormones, oxidative stress parameters and allopurinol remains to be explored. Methods: Forty-two Wistar albino rats were divided into three groups. Rats in group A served as negative controls, while group B had untreated thyrotoxicosis and group C received allopurinol. Hyperthyroidism was induced by daily 0.2 mg/kg L-thyroxine intraperitoneally in groups B and C; 40 mg/kg allopurinol were given daily intraperitoneally. Efficacy of the treatment was assessed after 72 h and 21 days, by measuring serum xanthine oxidase (XO), malondialdehyde (MDA), glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPx) and nitric oxide derivates (NO·x). Results: In both time periods, serum XO, MDA, GSH and NO·x levels were significantly increased after thyroid hormone induction (p<0.05). Levels of XO, MDA and NO·x decreased with allopurinol treatment (p<0.05). There was a remarkable decrease in triiodothyronine levels in group C after 72 h (p<0.05), and in both triiodothyronine and thyroxine levels in group C after 21 days (p<0.05). There was no difference between groups B and C in means of serum GSH, GR and GPx levels (p>0.05). Conclusions: This study suggests an association between allopurinol and the biosynthesis of thyroid hormones. Allopurinol prevents the hyperthyroid state, which is mediated predominantly by triiodothyronine and not by XO. This issue has to be questioned in further studies where allopurinol is administered in control subjects.

Completion thyroidectomy for thyroid cancer.

Abstract Background: Whether thyroid re-operations are associated with an increased complication risk is controversial. The aim of this study was to perform a retrospective analysis of patients undergoing re-operative surgery of the thyroid. We analyzed the safety and the impact of delay on complications before undertaking radicalization thyroidectomy. Material and Methods: From January 1996 to July 2002, 150 consecutive patients with thyroid cancer were treated in our institution. A total of 62 patients underwent completion thyroidectomy. Twenty-seven had undergone their initial operation in our centre. Medical and pathologic data were obtained retropectively. Results: Pathological examination of the specimen after completion surgery revealed malignancy in a total of 35% of 62 patients. The time interval between initial surgery and completion thyroidectomy ranged from 5 days to 24 months (mean 3.1 months). Complications after re-operation were transient recurrent nerve injury in 1.6%, transient hypoparathyroidism in 4.8%, permanent hypoparathyroidism in 1.6% and chylous discharge in 1.6% of the patients. There was no significant difference between complication rates in patients operated on within 90 days or those operated on after this period (p > 0.05). Conclusions: This study suggests that completion thyroidectomy is safe in the hands of experienced endocrine surgeons and the timing of re-operation has no impact on the development of complications.

Occurrence of Riedel’s Thyroiditis in the course of sub-acute thyroiditis

Riedel’s Thyroiditis is an uncommon form of chronic thyroiditis characterized by an invasive fibrosclerosis of the gland, often involving surrounding tissue. The relationship of Riedel’s Thyroiditis to other forms of thyroiditis is not clear. We presented a 47 year-old woman first diagnosed with sub-acute thyroiditis based on clinical findings and laboratory results. Eight months later, she had a thyroidectomy operation due to an enlargement of the thyroid gland and symptoms of compression. Histopathologic evaluation showed that she had Riedel’s Thyroiditis, but there were some histopathologic findings of sub-acute thyroiditis as well. Until now, there has only been one case reported in which Riedel’s Thyroiditis was diagnosed in a patient with a history of sub-acute thyroiditis in the literature. Although aetiology of Riedel’s Thyroiditis is unknown, it may develop in the course of sub-acute thyroiditis.

Tiroid papiller mikrokarsinomlarında multisentrisite

Tiroid kanseri, endokrin organ kaynakli kanserler arasinda en sik gorulenidir (1,2). Tiroid kanserlerinin yaklasik %85’ini papiller tiroid kanseri olusturmaktadir. Papiller kanserlerin bir alt grubu olarak siniflandirilan ve ≤10mm tumorler olan ‘papiller mikrokarsinomlar’ tum papiller kanserlerin %30’unu olusturmakta ve daha az agresif davrandiklari kabul edilmektedir (2-5). Yuksek sagkalim oranlarina ragmen bazi hastalarda lokal nuks ve metastazlar ortaya cikmakta ve bu durum daha agresif bir cerrahi tedaviyi gerektirebilmektedir. Her ne kadar literaturde tanimlamasi konusunda kargasa mevcut ise de ‘tiroid kanserinde multisentrisite’, tiroid kanserinin, ayni tiroid lobunda veya iki lob icerisinde birden fazla yerde bulunmasi olarak tanimlanir (6). Gunumuzde yaygin olarak kullanilan tani yontemleri ile papiller mikrokarsinom tanisini ve multisentrik ozelligini belirlemek kolay degildir. Mikrokarsinomlar genellikle palpe edilemez ve klinik olarak sessiz seyretmektedir. Otopsi calismalarinda papiller mikrokarsinom gorulme orani bolgesel olarak degismekle birlikte %0.01-%35 arasinda bildirilmektedir ve bu oranlar cogu papiller mikroarsinomun benign davranisli oldugunu desteklemektedir (2,3,7,8). Cogu mikrokarsinom tanisi ise ‘tesadufi’ olarak benign davranisli tiroid hastaligi nedeniyle ameliyat edilen hastanin piyesinin patolojik incelemesi sonucu ortaya cikmaktadir. Gunumuzde daha yuksek cozunurluklu ultrasonografi ve ultrasonografide kusku duyulan, capi 1 cm’den kucuk nodullere uygulaARAŞTIRMA YAZISI

Pyriform sinus perforation secondary to nasogastric tube insertion

The second most common site of hypopharyngeal perforations is the pyriform sinus.1 Themucosa of this hypopharyngeal structure is extremely thin and fragile, especially in its lateral portion, where only a small muscle layer separates it from the carotid sheath in the neck.2 Its perforation is usually seen as a complication of a traumatic endotracheal intubation and is potentially lethal.3 Most reports have consistently described operator experience.4 Herein, we report a locally advanced thyroid cancer case, which to our knowledge is a previously unreported case where nasogastric tube insertion resulted in iatrogenic pyriform sinus perforation. A 42-year-old woman applied complaining of a hoarse voice of 1-year duration. On examination, thyroid masses, each 3· 4 cm in size, in both lobes were palpated. Besides, she had an oblique scar because of previous neck surgery. She had no radiation or family history, but had a previous thyroid cancer surgery 20years ago in another hospital. Pathology of that resected specimen showed a follicular cancer of the thyroid. She did not obey the follow-up requests. During her recent admission, ultrasound imaging showed hypoechoic solid thyroid nodules in the left and right lobe, each 3· 4 cm in diameter. Scintigraphy showed cold nodules in both thyroid lobes. Fibre-optic laryngoscopy showed paralysis of the left vocal cord. Thyroid hormone profile was normal. Computed tomography of the thorax showed multiple metastatic nodules in both lungs. Further work-up did not show any other lesion. A palliative thyroidectomy was carried out. During surgery, because of suspicion of infiltration of a locally advanced disease, a nasogastric tube insertion into the oesophagus was requested to guide the dissection. After the tube was inserted blindly by an anaesthesia technician, the left pyriform sinus happened to be perforated accidentally. This was noted intraoperatively. The region of perforation was detected by reinserting the tube carefully. The perforation was closed primarily over a nasogastric tube without tension with absorbable sutures. Drainage of the paratracheal space was carried out. Enteral feeding through the nasogastric route was started immediately after the operation. The drainage tube was removed on the fifth postoperative day. No pharyngocutaneous fistulas were discovered. The patient had an uneventful postoperative course. She tolerated both solid food and liquids at the time of discharge and was discharged 7 days after the operation. The commonest cause of pyriform sinus perforation is iatrogenic, usually secondary to instrumentation. It is of great importance to identify this perforation during surgery because delay of the iatrogenic lesion may result in a catastrophe. It may have life-threatening consequences from retropharyngeal abscess, mediastinitis, septicaemia or meningitis.5 If the perforation is discovered at the time of surgery, as in our case, simple and immediate suture can solve the problem. Small defects can be adequately closed primarily over a nasogastric tube, whereas large defects or resections extending into the tongue base need to be reconstructed with tissue augmentation techniques. The pedicled sternocleidomastoid muscle flap interposition is recommended when it is necessary to reinforce the closure with vital tissue and to protect the pharynx from vertebrae and bone graft.6