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Dive into the research topics where Ayhan Koyuncu is active.

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Featured researches published by Ayhan Koyuncu.


Ejso | 2010

Validation of breast cancer nomograms for predicting the non-sentinel lymph node metastases after a positive sentinel lymph node biopsy in a multi-center study

A.S. Gur; Bulent Unal; U. Ozbek; Vahit Ozmen; F. Aydogan; S. Gokgoz; Bahadir M. Gulluoglu; E. Aksaz; Serdar Özbaş; S. Baskan; Ayhan Koyuncu; A. Soran

OBJECTIVE In the study, our aim was to evaluate the predictability of four different nomograms on non-sentinel lymph node metastases (NSLNM) in breast cancer (BC) patients with positive sentinel lymph node (SLN) biopsy in a multi-center study. METHODS We identified 607 patients who had a positive SLN biopsy and completion axillary lymph node dissection (CALND) at seven different BC treatment centers in Turkey. The BC nomograms developed by the Memorial Sloan Kettering Cancer Center (MSKCC), Tenon Hospital, Cambridge University, and Stanford University were used to calculate the probability of NSLNM. Area under (AUC) Receiver Operating Characteristics Curve (ROC) was calculated for each nomogram and values greater than 0.70 were accepted as demonstrating good discrimination. RESULTS Two hundred and eighty-seven patients (287) of 607 patients (47.2%) had a positive axillary NSLNM. The AUC values were 0.705, 0.711, 0.730, and 0.582 for the MSKCC, Cambridge, Stanford, and Tenon models, respectively. On the multivariate analysis; overall metastasis size (OMS), lymphovascular invasion (LVI), and proportion of positive SLN to total SLN were found statistically significant. We created a formula to predict the NSLNM in our patient population and the AUC value of this formula was 0.8023. CONCLUSIONS The MSKCC, Cambridge, and Stanford nomograms were good discriminators of NSLNM in SLN positive BC patients in this study. A newly created formula in this study needs to be validated in prospective studies in different patient populations. A nomogram to predict NSLNM in patients with positive SLN biopsy developed at one institution should be used with caution.


World Journal of Surgery | 2009

Efficacy of Chlorhexidine Gluconate During Surgery for Hydatid Cyst

Omer Topcu; Zeynep Sumer; Ersin Tuncer; Cengiz Aydin; Ayhan Koyuncu

BackgroundDissemination of protoscolices-rich fluid during surgery for hydatid cyst disease is a major cause of recurrence. Instillation of a scolicidal agent into a hepatic hydatid cyst before opening is the most commonly employed measure to prevent this serious complication. In this clinical study, the efficacy of 0.04% chlorhexidine gluconate (Chx-Glu) during hydatid cyst surgery was tested, and early-term results were evaluated.MethodsA total of 30 consecutive patients with 45 liver cysts were studied. Only type I and type II cysts were included. Cysts were punctured, and fluid was aspirated. The viability of protoscolices in this fluid was determined. Chx-Glu 0.04% was instilled into the cyst cavity. After 5 minutes of exposure, the cyst fluid was reaspirated and evaluated for the viability of protoscolices. Imprints of the germinative membranes were determined for protoscolices viability.ResultsAll protoscolices in 45 cysts evaluated were killed by 5 minutes of exposure to 0.04% Chx-Glu. The whole of the germinative membrane imprints contained dead protoscolices. Chx-Glu 0.04% did not cause any adverse effect on biliary tracts in communication with cysts. There was no recurrence during the 2-year follow-up period. There were also no mortality and no cavity-related complications.ConclusionsThis study shows that intracystic injection of 0.04% Chx-Glu is an effective measure against the dissemination of viable protoscolices. In addition, Chx-Glu is the most convenient scolicidal agent as per the criteria defined by the World Health Organization. Therefore, it can be used safely during hydatid cyst surgery. However, there remains the need to perform advanced comparative clinical studies on the efficacy of Chx-Glu and other scolicidal agents.


Pancreatology | 2002

Pancreatic Pseudotumor due to Peripancreatic Tuberculous Lymphadenitis

Mustafa Turan; Metin Şen; Ayhan Koyuncu; Cengiz Aydin; Nazif Elaldi; Sema Arici

Peripancreatic tuberculous lymphadenitis is a very rare and difficult diagnosis. We report herein a patient with a clinically solitary abdominal tuberculoma. A 68-year-old woman was admitted to our hospital with moderate-level obstructive jaundice due to a mass located between pylorus and head of the pancreas. There were no clinical signs or symptoms of tuberculosis in lungs or abdomen. After the diagnosis of a neoplasm of the pancreas was made, exploratory laparotomy was performed which revealed a conglomerated mass penetrating into the pancreas. Since an exact diagnosis could not be reached on the basis of frozen sections prepared during the operation, a standard Whipple procedure was performed. After the histopathological examination of the resected specimen revealed tuberculous lympadenitis, the patient was given antituberculous medication. The patient recovered well. An abdominal tuberculoma is often mistaken for a malignant neoplasm, and nonsurgical diagnosis and treatment of this entity continues to be a challenge.


Surgery Today | 2003

Sigmoid colon perforation as an unusual complication of Behçet's syndrome: report of a case.

Mustafa Turan; Metin Sen; Ayhan Koyuncu; Cengiz Aydin; Sema Arici

Abstract.A 47-year-old man with long-standing Behçets syndrome presented with an acute abdomen, and was found to have perforation of the sigmoid colon. Laparotomy revealed gangrenous changes in the sigmoid colon and perforation in the center of the affected segment. This is a very rare complication of Behçets disease, and we report this case to stress the importance of performing careful abdominal examination while evaluating patients with Behçets disease.


Surgery Today | 2003

Thyroid Hormone Supplementation in Sepsis : An Experimental Study

Murat Inan; Ayhan Koyuncu; Cengiz Aydin; Mustafa Turan; Sehsuvar Gökgöz; Metin Sen

Abstract.Purpose: The levels of thyroid hormones decrease in septic, critically ill, and major trauma patients who show a bad prognosis. The aim of this study was to investigate the effects of thyroid hormone supplementation on the sepsis criteria and mortality in an experimental sepsis model. Methods: Forty-eight Wistar-Albino rats were divided into four experimental groups. A cecum ligation and puncture was used as a sepsis model. Group I: sham; group II: a cecum ligation and puncture (control); group III: a cecum ligation and puncture +T3 (0.4 μg/100 g body weight/day) intraperitoneally; group IV: a cecum ligation and puncture +T4 (1 500 ng/100 g body weight/day) intramuscularly. The PCO2, leukocyte count, peritoneal bacterial content, neutropenia, and mortality rates were assessed in all groups. Results: The PCO2 levels decreased only in the control group (P < 0.05). The leukocyte counts were lower in the therapy groups (P < 0.05). The rate of neutropenia was seen much more in the control group (P < 0.05). The peritoneal bacteria content decreased in the therapy groups (P < 0.05). The mortality rate significantly decreased in the thyroid hormone-treated animals (P < 0.05). Conclusions: Thyroid hormone supplementation in septic rats had a beneficial effect on the sepsis criteria and also resulted in a lower rate of mortality.


Pathology & Oncology Research | 2006

The intratumoral microvessel density and expression of bFGF and nm23-H1 in colorectal cancer.

Sahande Elagoz; Reyhan Egilmez; Ayhan Koyuncu; Ahmet Muslehiddinoglu; Sema Arici

It has previously been reported that intratumoral microvessel density (IMD), and the expression of bFGF and nm23-H1 are useful prognostic markers in colorectal cancer (CRC). In this study, a total of 100 CRCs were evaluated histopathologically, and IMD, bFGF and nm23-H1 expression were assessed by immunohistochemistry. IMD of patients increased with grade and stage, and this increase was statistically significant (p<0.05). A significantly higher incidence of high bFGF expression scores was also associated with increasing grade and stage (p<0.05). However, there was no significant difference between the grades in nm23-H1 expression (p=0.234). nm23-H1 expression occurred with lower incidence in stages C1, C2 and D than in stages B1 and B2 (p<0.05). Thus, a negative correlation was found between nm23-H1 expression and stage or lymph node metastasis (LNM) (p<0.05). IMD and bFGF expression were positively correlated with grade, stage, LNM, and lymphovascular invasion. Although positive correlation was found between IMD and bFGF, nm23-H1 expression negatively correlated with both of them. As a result, in clinical practice, increased IMD and bFGF expression and decreased nm23-H1 expression may provide valuable information in characterizing the malignant phenotype.


Visceral medicine | 2006

The Effects of Various Scolicidal Agents on the Hepatopancreatic Biliary System

Ömer Topçu; Cengiz Aydin; Sema Arici; Mustafa Duman; Ayhan Koyuncu; Metin Sen

Sclerosing cholangitis is a rare but dreadful complication of liver hydatid surgery. Almost all scolicidal agents were shown to be potentially associated with this complication clinically or experimentally. This experimental study was designed to examine the effects of 0.04% chlorhexidine gluconate and 95% ethanol on the hepatobiliary system and pancreas and also to compare their effects with 10% povidone iodine and hypertonic 20% saline. Materials and Methods: 50 Wistar rats were divided into equal five groups identified as: 0.9% NaCl (control group), 0.04% chlorhexidine gluconate, hypertonic 20% saline, 10% povidone iodine, and 95% ethanol. Scolicidal agents were injected into the biliary tract through a duodenal puncture. The animals were kept for 3 months. The animals were sacrificed, and histopathological examinations of the liver, biliary tract, and pancreas were performed. Results: The most severe histopathological changes of the liver, biliary tract, and pancreas were found in the ethanol group, and the least changes were detected in the chlorhexidine gluconate group. Conclusion: This experimental study confirms the deleterious effect of 95% ethanol on hepatopancreatic biliary system when used for the percutaneous drainage of hydatid diseases. For treatment of hydatid cysts in the hepatobiliary system, 0.04% chlorhexidine gluconate should be used as scolicidal agent.


Journal of Gastroenterology | 2003

Relaxant effect of omeprazole and lansoprazole in guinea pig gallbladder muscle strips in vitro

Cengiz Aydin; Bulent Sarac; Ayhan Koyuncu; Sahin Yildirim; Metin Sen; Yusuf Sarioglu

Background. The aim of this study was to investigate the role of omeprazole and lansoprazole, H+-K+ ATPase inhibitors, in gallbladder smooth muscle contractility in vitro. Methods. Gallbladder muscle strips obtained from guinea pigs were mounted in an organ bath. The responses of both precontracted strips and strips under basal tension to omeprazole and lansoprazole were determined. Results. Spontaneous contractile activity was blocked following omeprazole and lansoprazole administration. The agents also caused concentration-dependent relaxation in carbachol- and KCl-precontracted gallbladder muscle strips. Pretreatment with atropine (1 µM), NW-nitro l-arginine methyl ester (l-NAME; 30 µM), indomethacin (10 µM), ammonium chloride (7.5 mM), sodium acetate (7.5 mM), tetraethylammonium chloride (0.5 mM), glibenclamide (1 µM), 4-aminopyridine (0.1 mM), or clotrimazole did not inhibit this relaxation. Gallbladder strips were placed in high-concentrtion potassium (80 mM), calcium-free solution. The contraction produced with the addition of Ca2+ (2.5 mM) was completely relaxed by omeprazole, lansoprazole, and nifedipine separately. Conclusions. These results demonstrate that omeprazole and lansoprazole have potent inhibitory effects on spontaneous contractions and cause dose-dependent relaxation in precontracted gallbladder smooth muscle strips of guinea pig in vitro. This effect could be due to blockade of the calcium channels.


European Journal of Public Health | 2015

Factors affecting breast cancer treatment delay in Turkey: a study from Turkish Federation of Breast Diseases Societies

Vahit Ozmen; Sukru Boylu; Engin Ok; Nuh Zafer Cantürk; Varol Celik; Murat Kapkac; S. Z. Siretioglu Girgin; Mustafa Tireli; Enver Ihtiyar; Orhan Demircan; Mazhar Semih Baskan; Ayhan Koyuncu; Ismet Tasdelen; Esra Dumanli; Fatih Ozdener; Piotr Zaborek

Background: One of the most important factors in breast cancer (BC) mortality is treatment delay. The primary goal of this survey was to identify factors affecting the total delay time (TDT) in Turkish BC patients. Methods: A total of 1031 patients with BC were surveyed using a uniform questionnaire. The time between discovering the first symptom and signing up for the first medical visit (patient delay time; PDT) and the time between the first medical visit and the start of therapy (system delay time; SDT) were modelled separately with multilevel regression. Results: The mean PDT, SDT and TDT were 4.8, 10.5 and 13.8 weeks, respectively. In all, 42% of the patients had a TDT >12 weeks. Longer PDT was significantly correlated with disregarding symptoms and having age of between 30 and 39 years. Shorter PDT was characteristic of patients who: had stronger self-examination habits, received more support from family and friends and had at least secondary education. Predictors of longer SDT included disregard of symptoms, distrust in success of therapy and medical system and having PDT in excess of 4 weeks. Shorter SDT was linked to the age of >60 years. Patients who were diagnosed during a periodic check-up or opportunistic mammography displayed shorter SDT compared with those who had symptomatic BC and their first medical examination was by a surgeon. Conclusion: TDT in Turkey is long and remains a major problem. Delays can be reduced by increasing BC awareness, implementing organized population-based screening programmes and founding cancer centres.


Surgery Today | 2010

Could total thyroidectomy become the standard treatment for Graves’ disease?

Ayhan Koyuncu; Cengiz Aydin; Omer Topcu; Oruç Numan Gökçe; Şahande Elagöz; Hatice Sebila Dökmetaş

PurposeGraves’ disease is the most frequent cause of hyperthyroidism. Although treatment with antithyroid drugs or radioactive iodine is effective, surgery remains the preferred treatment for many patients. We analyzed the results of 55 prospectively followed patients who underwent total thyroidectomy for Graves’ disease.MethodsTotal thyroidectomy was performed by experienced endocrine surgeons in all 55 patients. We monitored the patients postoperatively for early and late complications.ResultsThere were 19 men, with a mean age of 42 years (range, 34–68 years) and 36 women, with a mean age of 38 years (range, 19–78 years). One patient suffered postoperative hemorrhage and subsequent wound infection, two patients had transient recurrent laryngeal nerve palsy, and 24 patients had transient hypocalcemia. The mean follow-up time was 4 years (range, 10 months to 6 years). Recurrence of hyperthyroidism was not reported in this period.ConclusionRemoval of all thyroid tissue offers the best chance of preventing recurrent hyperthyroidism. Total thyroidectomy is the most effective surgery for achieving the goal of treatment of Graves’ disease to ensure that hyperthyroidism will not recur.

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Metin Sen

Cumhuriyet University

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