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Dive into the research topics where Yusuf Peker is active.

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Featured researches published by Yusuf Peker.


Scandinavian Journal of Clinical & Laboratory Investigation | 2011

Comparison of hyperbaric oxygen and medical ozone therapies in a rat model of experimental distal colitis

Ozcan Altinel; Seref Demirbas; Erdinc Cakir; Halil Yaman; Ismail Hakki Ozerhan; Eyup Duran; Emin Ozgur Akgul; Nail Ersoz; Bulent Uysal; Bulent Kurt; Mehmet Yasar; Sukru Oter; Yusuf Peker

Abstract Objectives. Previous studies have shown that hyperbaric oxygen (HBO) is effective in reducing the severity of acute distal colitis (ADC). Ozone therapy (OT) reduces inflammation in several pathological conditions. We aimed to compare the effects of HBO therapy and OT in an experimental ADC rat model. Materials and methods. Forty rats were randomly divided into four groups: Sham, ADC, ADC + HBO, and ADC + OT. Rats in the sham group were given isotonic saline. In the remaining groups, ADC was created by intracolonic administration of 4% acetic acid. No treatment was given to the ADC group. The rats in the ADC + HBO and ADC + OT groups were given HBO and ozone treatments, respectively. The administration of acetic acid caused an inflammatory response in all animals. Distal colons and blood samples were obtained. Results. The histopathological score was significantly higher in the ADC group compared to the other groups. The histopathological scores in the ADC + HBO and ADC + OT groups were significantly lower compared to the ADC group (both p < 0.001). The most pronounced therapeutic effect was observed in the ADC + OT group. Malondialdehyde and neopterin levels and superoxide dismutase and glutathione peroxidase activities in the ADC group were significantly higher compared to the other groups (p < 0.001). Conclusion. Our data showed that the therapeutic effect of OT is more pronounced than that of HBO therapy. Its possible effect is by means of decreasing inflammation, edema, and oxidative stress. These findings also suggest that it is possible to improve the outcome of ADC by using ozone therapy as an adjuvant therapy.


World Journal of Gastroenterology | 2013

Biliary fistula after treatment for hydatid disease of the liver: when to intervene.

Nazif Zeybek; Hakan Dede; Deniz Balci; Ali Coskun; Ismail Hakki Ozerhan; Subutay Peker; Yusuf Peker

AIM To determine the outcome of patients with biliary fistula (BF) after treatment for hydatid disease of the liver. METHODS Between January 2000 and December 2010, out of 301 patients with a diagnosis of hydatid cyst of the liver, 282 patients who underwent treatment [either surgery or puncture, aspiration, injection and reaspiration (PAIR) procedure] were analysed. Patients were grouped according to the presence or absence of postoperative biliary fistula (PBF) (PBF vs no-PBF groups, respectively). Preoperative clinical, radiological and laboratory characteristics, operative characteristics including type of surgery, peroperative detection of BF, postoperative drain output, morbidity, mortality and length of hospital stays of patients were compared amongst groups. Multivariate analysis was performed to detect factors predictive of PBF. Receiver operative characteristics (ROC) curve analysis were used to determine ideal cutoff values for those variables found to be significant. A comparison was also made between patients whose fistula closed spontaneously (CS) and those with intervention in order to find predictive factors associated with spontaneous closure. RESULTS Among 282 patients [median (range) age, 23 (16-78) years; 77.0% male]; 210 (74.5%) were treated with conservative surgery, 33 (11.7%) radical surgery and 39 (13.8%) underwent percutaneous drainage with PAIR procedure A PBF developed in 46 (16.3%) patients, all within 5 d after operation. The maximum cyst diameter and preoperative alkaline phosphatase levels (U/L) were significantly higher in the PBF group than in the no-PBF group [10.5 ± 3.7 U/L vs 8.4 ± 3.5 U/L (P < 0.001) and 40.0 ± 235.1 U/L vs 190.0 ± 167.3 U/L (P = 0.02), respectively]. Hospitalization time was also significantly longer in the PBF group than in the no-PBF group [37.4 ± 18.0 d vs 22.4 ± 17.9 d (P < 0.001)]. A preoperative high alanine aminotransferase level (> 40 U/L) and a peroperative attempt for fistula closure were significant predictors of PBF development (P = 0.02, 95%CI: -0.03-0.5 and P = 0.001, 95%CI: 0.1-0.4), respectively. Comparison of patients whose PBF CS or with biliary intervention (BI) revealed that the mean diameter of the cyst was not significantly different between CS and BI groups however maximum drain output was significantly higher in the BI group (81.6 ± 118.1 cm vs 423.9 ± 298.4 cm, P < 0.001). Time for fistula closure was significantly higher in the BI group (10.1 ± 3.7 d vs 30.7 ± 15.1 d, P < 0.001). The ROC curve analysis revealed cut-off values of a maximum bilious drainage < 102 mL and a waiting period of 5.5 postoperative days for spontaneous closure with the sensitivity and specificity values of (83.3%-91.1%, AUC: 0.90) and (97%-91%, AUC: 0.95), respectively. The multivariate analysis demonstrated a PBF drainage volume < 102 mL to be the only statistically significant predictor of spontaneous closure (P < 0.001, 95%CI: 0.5-1.0). CONCLUSION Patients with PBF after hydatid surgery often have complicated postoperative course with serious morbidity. Patients who develop PBF with an output < 102 mL might be managed expectantly.


International Wound Journal | 2014

A simple novel technique for enteroatmospheric fistulae: silicone fistula plug

M. Tahir Özer; Huseyin Sinan; Nazif Zeybek; Yusuf Peker

Enteroatmospheric fistulae (EAFs), a rare condition that develops in patients treated with an open abdomen, present serious problems for the surgeon. There are no fixed algorithms for treatment of EAF, and treatment options are determined based on the experience of the surgeon and status of the patient. We developed a ‘suspended silicone fistula plug’ for treating a patient who developed an EAF after undergoing multiple operations in a short period of time. Used in conjunction with negative pressure wound therapy, application of this novel therapy resulted in EAF closure and patient discharge.


Journal of Investigative Surgery | 2005

Comparison of Urografin versus standard therapy in postoperative small bowel obstruction.

Gokhan Yagci; Nihat Kaymakcioglu; Mehmet Fatih Can; Yusuf Peker; Sadettin Cetiner; Turgut Tufan

Water-soluble contrast media (Urografin) cause redistribution of intravascular and extracellular fluid into intestinal lumen due to their hyperosmolarity. As a consequence, these media decrease intestinal wall edema and act as a direct stimulant to intestinal peristalsis. In this prospective study, we aimed to examine objectively the therapeutic role and ability of Urografin in patients with postoperative small bowel obstruction for whom failed to respond to conservative treatment. Three hundred and seventeen patients with postoperative small bowel obstruction due to intraperitoneal adhesions were included prospectively in this study. In the Urografin group, 40 mL Urografin diluted in 40 mL distilled water was administered through the nasogastric tube. No contrast media were administered in the control group, but the patients were decompressed via a nasogastric tube continuously. The number of obstruction episode in 317 patients was 338. In total, 199 patients were in the Urografin group, and 118 patients were in the control group. In the Urografin group, 178 (89.4%) patients responded successfully to the treatment, but 21 (11.6%) patients underwent surgical operation. Intensive intraabdominal adhesions and obstructing fibrous bands were observed and repaired in 15 (71.4%) patients at the operation, while 6 patients underwent segmental small intestine resection in control group, conventional management was successful in only 89 (75.4%) patients, and the remaining 29 (24.6%) patients underwent surgical intervention. In conclusion, it was suggested that in patients with intestinal obstruction due to postoperative intra-abdominal adhesion, water-soluble contrast media such as Urografin may be safely administered via a nasogastric tube or oral route and may decrease the need for surgical operation; furthermore, they may help the physician to operate the patients who needs surgery as early as possible.


Journal of Surgical Research | 2008

Comparison of Modified Darn Repair and Lichtenstein Repair of Primary Inguinal Hernias

Nazif Zeybek; Hüseyin Taş; Yusuf Peker; Fahrettin Yildiz; Ali Akdeniz; Turgut Tufan

OBJECTIVE This study was designed to compare the results of the Modified Darn Repair through Lichtenstein procedure in inguinal hernias. MATERIALS AND METHODS The study involved 322 patients with inguinal hernia, operated in General Surgery Departments of Gulhane Military Medical Academy and Sirnak Military Hospital between 1998 and 2004. The durations of operation time, hospitalization, and time to return to daily activities and postoperative complication and recurrence rates were evaluated. Lichtenstein procedure was applied on 170 patients (Group 1), and modified darn repair was applied on 152 patients (Group 2). RESULTS The average follow-up period was 56 months. For the Lichtenstein procedure, the average duration of operation was 56 min; the average time to return to routine activities was 20 days. The number of patients with postoperative complications was 20 (11.7%), and the number of patients with recurrence was 1 (0.6%). For modified darn repair, the average duration of operation was 48 min; the time to return to daily activities was 20 days. The number of patients with postoperative complication was three (1.9%), and no recurrences were noted. The hospitalization time of the groups was similar. DISCUSSION Modified darn repair is a reliable method for inguinal hernia repair with short hospitalization time, low rate of postoperative complications, and recurrence.


Turkish journal of trauma & emergency surgery | 2011

The affecting factors on the complication ratio in abdominal gunshot wounds

Hüseyin Taş; Ayhan Mesci; Mehmet Eryilmaz; Nazif Zeybek; Yusuf Peker

BACKGROUND We aimed to investigate the affecting factors on the complication ratio in abdominal gunshot wounds. METHODS Twenty-one patients with abdominal gunshot wounds were analyzed between February 2002 and May 2005. The effects of the interval between trauma and presentation to the hospital, the number of injured abdominal and extra-abdominal organs, penetrating abdominal trauma index (PATI), and blood transfusion were evaluated. RESULTS 90.4% of all patients were transported to the hospital and underwent their first evaluation in the first two hours. The complication rate was 7.1% in patients who had <3 injured organs and 71% in the others (p<0.0001). 71.4% of the patients had isolated abdominal trauma, while 28.6% had additional extra-abdominal organ trauma. The complication rate was 7.7% in 13 patients with PATI score <25 and 62.5% in 8 patients with a PATI score ≥25 (p<0.0001). In 10 patients who underwent blood transfusion of ≥3 units, the complication rate was 50% (p<0.0001). CONCLUSION In our study, PATI score, multiple blood transfusions and the number of injured intra-abdominal organs were the most important factors affecting the rate of postoperative complications in penetrating abdominal gunshot wounds. We found that the interval between trauma and presentation to the hospital and number of injured extra-abdominal organs did not affect the complication rate.


Vascular | 2017

The value of combined elevation of D-dimer and neopterin as a predictive parameter for early stage acute mesenteric ischemia: An experimental study.

Ali Kagan Coskun; Zekai Halici; Akgun Oral; Yasin Bayir; Ferhat Deniz; Öner Menteş; Bilgehan Savas Oz; Ali Harlak; Taner Yigit; Orhan Kozak; Yusuf Peker

Background The diagnosis of acute mesenteric ischemia is variable. Early diagnosis is important for reducing the mortality and morbidity rates. Aim This experimental study aims to investigate the diagnostic utility of D-dimer and neopterin as a marker for the early stage of acute mesenteric ischemia caused by occlusion of superior mesenteric artery. Methods The levels of D-dimer and neopterin were measured using an animal acute mesenteric ischemia model in 21 male rabbits. Superior mesenteric artery occlusion (Group 1, n = 14) and control (Group 2, n = 7) groups were identified. Blood samples at different times are collected from each rabbits. Blood samples from superior mesenteric artery occlusion group were taken 30 min after anesthesia but before laparotomy, 1, 2, and 3 h after superior mesenteric artery ligation. Blood samples from control group were taken 1 h before, 1 and 3 h after anesthesia and laparotomy. The D-dimer and neopterin levels of each blood sample were measured. Results The probability of acute mesenteric ischemia was found to be 36 times higher when the D-dimer level was over 0.125 ng/L, whereas the probability was 19.2 times higher when the neopterin level was over 1.25 nmol/L. Conclusions In this experimental study, the combined elevation of two significant markers, D-dimer and neopterin, may be helpful for the early diagnosis of acute mesenteric ischemia.


International Wound Journal | 2014

Use of self‐expanding covered stent and negative pressure wound therapy to manage late rectal perforation after injury from an improvised explosive device: a case report

M. Tahir Özer; Ali Kagan Coskun; Huseyin Sinan; Mehmet Saydam; Emin O Akay; Subutay Peker; Gokhan Ogunc; Sezai Demirbas; Yusuf Peker

Blast injuries, caused by explosions accompanied by high‐pressure waves, produce tissue damage in the acute period, followed in the later period by circulatory disorders due to vascular endothelial damage and related tissue necrosis. Blunt rectal perforation is rare and difficult to diagnose. In the acute period following blast pelvic injuries, the main objectives are to stop bleeding, minimise contamination and preserve the patients life. The patient in this report had major vascular injuries, severe pelvic injury and, in the later period, rectal perforation because of vascular endothelial damage caused by the blast effect. Our aim was to treat the patient conservatively because of his poor general condition. We placed a self‐expanding covered stent (SECS) into the rectum and then applied negative pressure wound therapy (NPWT; V.A.C.® Therapy, KCI) to the pelvic region and perirectal area. At the end of the treatment, the rectal perforation was closed, and the patient was discharged with healing. In this article, we discuss the novel use of an SECS with NPWT and review related literature.


Liver International | 2008

Management of bronchobiliary fistulas caused by liver hydatid disease.

Mehmet Fatih Can; Yusuf Peker

To the Editor: We read with interest the article on the management of hydatid bronchobiliary fistulas (BBF) by Tocchi et al. (1), but we have questions and issues regarding their management strategy in patients with BBF. Firstly, they mentioned that their patients with liver echinococcosis underwent surgical procedures. Is it their policy to treat all patients with liver hydatidosis surgically, or did their study only include patients managed by means of operative procedures? As we all know, today, many patients with liver hydatid cysts can be treated using a combination of topical scolicidal agents and minimally invasive methods. Our institution’s cumulative experience with these methods currently exceeds 200 cases (2). Secondly, the report did not point out if they attempted to resect lung parenchyma damaged by biliary secretions. In addition, the authors concluded that radical excision of the pericyst is mandatory to avoid infectious complications. To our opinion, extended unroofing of the pericyst and decompressing the cavity by removing all of the intracystic vesicles may be a reasonable option, provided no accompanying infectious findings have been identified. In the same operation, excision of the fistula tract also should be performed. It is our clinical policy, if required and possible, to decompress biliary flow by pre-operative endoscopic intervention. Third, why did the authors not administer medical treatment consisting of any of the effective anti-parasitic agent? These medications are frequently utilized in the management of liver echinococcosis, especially as an adjunct to surgery or minimally invasive procedures. Their patients developed BBF; but did this happen after successful management of hydatid disease? If so, medical therapy is not the topic of conversation. But in this situation, the authors’ preference for ‘operative management for all cases with BBF’ might be considered controversial. Fourth, the report reveals that each of the patients who developed BBF had only one cyst in the liver. It is well known that many patients with liver hydatidosis have more than one cystic lesion; these may present at different stages at the same time. We wonder whether the authors reserved the results of their multicystic cases for a further publication. If not, how could they explain this ‘single cyst in each of the 31 patients’ situation? In addition, eight patients had undergone previous hepatic surgery for hydatid disease. Did the presence of recurrent disease alter the authors’ surgical approach? Finally, the authors’ fundamental approach emphasizes extended surgical access as an unalterable component of management. As can be recognized in our recently published paper (3), numerous suggestions for the treatment of BBFs exist, and selecting appropriately among the various suggested methods requires the use of an algorithm drawn with casebased strategy. Based upon a detailed review of previous evidence, our contribution is a case-based algorithm, by which we hope to optimize the management of BBFs. From this point of view, we propose that in selected cases less-invasive methods may be preferable. In short, we feel that the adoption of an algorithmic approach to the management of BBFs may best satisfy the needs of surgeons and patients alike.


Case Reports in Surgery | 2018

BRAF Inhibitors for BRAF V600E Mutant Colorectal Cancers: Literature Survey and Case Report

Yasar Subutay Peker; Mehmet Fatih Can; Ismail Hakki Ozerhan; Gokhan Yagci; Nazif Zeybek; Kutan Kavakli; Sedat Gürkök; Alper Gözübüyük; Onur Genç; Gokhan Erdem; Ahmet Ozet; Mustafa Gerek; Yusuf Peker

The main method of fighting against colon cancer is targeted treatment. BRAF inhibitors, which are accepted as standard treatment for V600E mutant malign melanomas, are the newest approach for targeted treatment of V600E mutant colorectal cancers. In this case report, we share our experience about the use of BRAF inhibitor vemurafenib on a V600E mutant metastatic right colon adenocarcinoma patient. A 59-year-old male with only lung multiple metastatic V600E mutant right colon cancer presented to our clinic. The patient was evaluated and FOLFOX + bevacizumab treatment was initiated, which was then continued with vemurafenib. A remarkable response was achieved with vemurafenib treatment in which the drug resistance occurred approximately in the sixth month. Even though the patient benefited majorly from vemurafenib, he died on the 20th month of the diagnosis. The expected overall survival for metastatic V600E mutant colon adenocarcinoma patients is 4.7 months. BRAF inhibitors provide new treatment alternatives for V600E mutant colorectal cancers, with prolonged overall survival. BRAF inhibitors in combination with MEK inhibitors are reported as feasible treatment to overcome BRAF inhibitor drug resistance on which phase studies are still in progress. To conclude, BRAF inhibitors alone or in combination with other drugs provide a chance for curing BRAF V600E mutant colorectal cancer patients.

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Nazif Zeybek

Military Medical Academy

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Gokhan Yagci

Military Medical Academy

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Turgut Tufan

Military Medical Academy

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Erkan Ozturk

Military Medical Academy

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Nail Ersoz

Military Medical Academy

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