Mahir Akyildiz

A Multivariate Analysis of Objective Voice Changes After Thyroidectomy Without Laryngeal Nerve Injury

OBJECTIVE To evaluate the impact of thyroidectomy and the possible effects of factors such as patient sex, operation type, and surgeon experience on objective voice parameters of patients undergoing thyroidectomy without laryngeal nerve injury. DESIGN Prospective study. SETTING University hospital. PATIENTS Thirty-six patients undergoing primary thyroidectomy because of thyroid disease. MAIN OUTCOME MEASURES The effect of thyroidectomy on voice was examined by recording the voices of the patients before and 1 week after thyroidectomy. The Multi-Dimensional Voice Program was used for capturing and analyzing the voice samples. RESULTS On postoperative examination of objective voice changes, thyroidectomy had no multivariate effect on the combination of voice parameters. Patient sex, type of surgery, and surgeon experience had no effect on the combination of voice parameters before and after thyroidectomy. Regardless of within-patient factors (type of surgery, patient sex, and surgeon experience), 4 acoustic parameters (highest fundamental frequency, standard deviation of average fundamental frequency, phonatory average fundamental frequency range in semitones, and degree of subharmonics) significantly decreased after thyroidectomy (P < .05). Although they tended to be worse, none of the acoustic parameters showed significant changes in male patients. However, significant changes in some of the acoustic parameters of female patients were observed. Highest fundamental frequency, standard deviation of average fundamental frequency, phonatory average fundamental frequency range in semitones, absolute jitter, relative average perturbation, pitch perturbation quotient, shimmer in decibels, percentage of shimmer, amplitude perturbation quotient, noise to harmonic ratio, and degree of subharmonics values were all lower in female patients after thyroidectomy (P < .05). CONCLUSIONS Voice changes may occur after thyroidectomy without any evident laryngeal injury, and deterioration and amelioration of acoustic parameters can be observed to occur differently among male and female patients. Preoperative and postoperative objective voice analyses may be helpful in documenting voice changes.

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.

Effects of Somatostatin Analogues and Vitamin C on Bacterial Translocation in an Experimental Intestinal Obstruction Model of Rats

The passage of viable endogenous bacteria and their products across the intact intestinal mucosal barrier, disseminating to the mesenteric lymph nodes, peritoneal cavity, spleen, liver, and circulation, is defined as bacterial translocation. Intestinal obstruction induces bacterial translocation due to mucosal disruption, motility dysfunction, and increased intestinal volume, leading to bacterial overgrowth. In a rat model of intestinal obstruction, the effects of both high-dose vitamin C (350 microg/kg), an antioxidant agent known to have a cytoprotective effect in ischemia-reperfusion injury, and somatostatin (20 microg/kg), a gastrointestinal antisecretory agent, in preventing bacterial translocation were studied. Both intestinal and liver samples from the rats was observed, and it was found that the rate of bacterial translocation was 100% in the control group, and only 43% for the rats who were given intraperitoneal vitamin C and somatostatin. The difference was statistically significant. In conclusion, we are convinced that vitamin C and somatostatin analogues may have protective effects against bacterial translocation in mechanical bowel obstruction.

Should Subtotal Thyroidectomy Be Abandoned in Multinodular Goiter Patients From Endemic Regions Requiring Surgery

The most convenient surgical procedure for benign thyroid diseases is still controversial. The aim of this study is to determine the recurrence rate and risk factors for recurrence after different thyroidectomy procedures in multinodular goiter patients. Patients were separated into two groups according to the detection of a recurrent nodule or not after thyroidectomy. Of the 748 patients, 216 (29%) had recurrence, while 532 had no recurrent nodule. The difference between surgical procedures described as subtotal (ST), near total (NT) and total thyroidectomy (TT) was statistically significant. Transient hypoparathyroidism was significantly higher in NT and TT, when compared to ST patients (P < 0.05). Young age, bilateral multinodular goiter and insufficient surgery are risk factors affecting recurrence for benign nodular thyroid disease. Currently, subtotal procedures should be discontinued and total or near total procedures should be preferred. Meanwhile, the probability of a higher risk of hypoparathyroidism should be kept in mind.

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

Routine calcitonin measurement in nodular thyroid disease management: is it worthwhile?

Purpose To evaluate the diagnostic accuracy of routine calcitonin measurement in patients with nodular thyroid disease. Methods Consecutive patients with nodular thyroid disease (n = 640) were studied. Serum calcitonin levels were measured under basal conditions, and when basal values were between 10–100 pg/mL, testing was repeated after pentagastrin (PG) stimulation. Patients with previously diagnosed or familial medullary thyroid cancer (MTC) were excluded. Patients were operated on when basal or stimulated calcitonin >100 pg/mL or when other surgical indications were present. Results Four cases of MTC were identified. MTC was diagnosed in 75% of patients with basal calcitonin >100 pg/mL. One out of 11 patients with basal calcitonin between 10–100 pg/mL was diagnosed with MTC. PG stimulation resulted in elevation in 4 cases, where 1 case was diagnosed with MTC. Positive predictive value for basal calcitonin levels in the preoperative diagnosis of MTC was 5% for values between 10–100 pg/mL and 100% for values >100 pg/mL. Possible reasons for false positivity were papillary thyroid cancer in 17%, renal insufficiency in 8.3%, Hashimoto thyroiditis in 17% and β-blocker use in 33%. Positive predictive value for the PG test (>100 pg/mL) was 25% in the entire series. The cost of adding calcitonin measurement (±PG stimulation) to the preoperative work-up, resulted in €912.68 per MTC patient to detect the disease. Conclusion Basal calcitonin measurement together with PG stimulation in cases of basal calcitonin >10 pg/mL detects MTC in 0.62% of patients with nodular thyroid disease.

What adds Valsalva maneuver to hemostasis after Trendelenburg's positioning during thyroid surgery?

Background Bleeding after thyroidectomy is life-threatening. The aim of the study was to evaluate whether controlling of further bleeding with Valsalva maneuver following Trendelenburgs positioning has an impact on hemostasis. Methods This prospective study included 68 consecutive patients undergoing thyroidectomy. Study protocol consisted of performing manual intra-abdominal pressure increase and Valsalva maneuver to check hemostasis and treating any bleeding point identified, after Trendelenburgs positioning. All identified bleeding points and treatments were recorded. Results Total number of bleeding points identified in Trendelenburgs tilt was 49, while it was 41 when using Valsalva maneuver. Abdominal pressure increase, carried out before Valsalva maneuver, identified 14 bleeding points, which was less than bleeding after Trendelenburgs positioning and Valsalva maneuver (P<0.05). All bleeding points, except 1 for Trendelenburgs positioning and 1 for Valsalva maneuver, were minor (<2 mm). Only 4.4% bleeding vessels required ties or stitching. Conclusions Valsalva maneuver helps to detect any further bleeding following Trendelenburgs positioning.

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

Robot-assisted endoscopic mediastinal parathyroidectomy

Ectopic parathyroid glands can be located at any anatomical location from the base of the tongue to the mediastinum. One-third of these glands migrate deep into the mediastinum, which are not accessible with a low cervical incision. In this article, we described the robotic approach to an ectopic mediastinal parathyroid gland. This management method of mediastinal adenomas has significant advantages when compared to conventional surgery.