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Dive into the research topics where Abdurrahim Colak is active.

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Featured researches published by Abdurrahim Colak.


Renal Failure | 2006

Primary Arteriovenous Fistulas in the Forearm for Hemodialysis: Effect of Miscellaneous Factors in Fistula Patency

Bilgehan Erkut; Yahya Ünlü; Münacettin Ceviz; Necip Becit; Azman Ates; Abdurrahim Colak; Hikmet Koçak

Background. The provision and maintenance of vascular access remains a major cost to end-stage renal failure programs. In addition, vascular access occlusion, results in significant morbidity in hemodialysis patients. Age, gender, diabetes mellitus, malignancy, smoking habits, administration of heparin per hemodialysis session, previous dialysis catheter insertion, number of hemodialysis sessions and location of the fistula may be associated with survival of the primary arteriovenous fistula. We examined the effects of various factors on fistulas in 412 chronic renal insufficiency patients. Methods. From 1995 to 2004, 412 arteriovenous fistulas were created by the Department of Cardiovascular Surgery at the Medical Faculty of Atatürk University for hemodialysis. The mean age of the patients was 45 years (range 6 to 62 years). We evaluated the effects of various factors for patency rates in the patients who had primary arteriovenous fistulas. Primary patency was defined as the duration of fistula patency without revision. Twenty-eight patients (6.7%) with ischemic cardiac disease did not require surgical interference. Analyzed data were age, gender, smoking habits, diabetes mellitus, malignant neoplasm, previous dialysis catheter insertion, number of hemodialysis sessions, and fistula location. Results. In 298 patients, where lower-arm radiocephalic fistulas were created, the fistula patency was 74.1%, 64.2%, 49.8%, 33.7%, and 4.1% after 1, 2, 3, 4, and 5 years, respectively, in the other 114 patients, where upper-arm fistulas were created, these rates were 84.0%, 72.2%, 53.3%, 39.8%, and 12.3%, respectively. There was no significantly difference between the upper-arm fistulas and the lower-arm fistulas statistically (p = 0.069). Factors affecting the primary patency of arteriovenous fistulas were diabetes mellitus (p = 0.0001), hemodialysis counts ≥3 per week (p < 0.0005), presence of malignancy (p < 0.0005), previous catheter insertion (p < 0.0007), and administration of heparin per hemodialysis session (p = 0.0008). Conclusion. While primary arteriovenous fistula patency was shortened in chronic renal insufficiency patients with diabetes mellitus, presence of malignancy, and previous catheter insertion, patency was longer in patients with heparin used for hemodialysis and hemodialysis count per week (≥3).


Acta Neurochirurgica | 2007

Iatrogenic vascular injury during to lumbar disc surgery

Bilgehan Erkut; Yahya Ünlü; Mehmet Ali Kaygin; Abdurrahim Colak; A. F. Erdem

SummaryWe report two patients who sustained vascular injury while undergoing intervertebral disc surgery at the lumbar four and five level. Each patient suffered from massive bleeding and shock, urgent laparatomy was performed, and the vascular injuries were successfully primarily repaired. The experience prompted us to review reports in the literature since 1965 of vascular complications associated with surgical excision of hernia disc via a posterior approach. From our analysis, we highlight the clinical features and management, emphasising that rapid diagnosis and immediate intervention can result in a favourable outcome, as in our patients.


Liver Transplantation | 2015

Liver transplantation for alveolar echinococcosis in an endemic region

Bulent Aydinli; Gürkan Öztürk; Sukru Arslan; Mecit Kantarci; Onder Tan; Ali Ahiskalioglu; Kemalettin Özden; Abdurrahim Colak

Alveolar echinococcosis (AE) is a chronic disease caused by ingestion of the eggs of the parasitic cestode Echinococcosis multilocularis (EM). In severe cases, liver transplantation (LT) may represent the only possibility of survival and cure. Patients undergoing LT associated with hepatic AE at our institution between April 2011 and October 2014 were investigated retrospectively. The clinical findings of the 27 patients who participated in the study were noted. Kaplan‐Meier and chi‐square tests were used to investigate the effect of these characteristics on survival and mortality. Living donor LT was performed on 20 patients (74.1%), and deceased donor LT was performed on 7 patients (25.9%). Hilar invasion was the most common indication (14 patients, 51.9%) for transplantation. The patient follow‐up was 16.1 ± 11.4 months, and the overall survival rate was 77.8%. Primary nonfunction developed only in 2 patients in the posttransplantation period. Six patients died during monitoring, the most common cause of death being sepsis (3 patients). The relationship between the mortality rate of the patients and the invasion of the bile duct and/or portal vein by alveolar lesions was found to be statistically significant (P = 0.024 and P = 0.043, respectively). According to PNM staging, when the AE disease exceeds the resectability limits, the only alternative for the treatment of the disease is LT. However, different from LT due to cirrhosis, it is extremely difficult to perform a transplantation for AE disease because of the invasive characteristics of it. In order to decrease the difficulty of the operation and the postoperative mortality, the intracystic abscess and cholangitis which occur because of AE must be treated via medical and percutaneous methods before transplantation. Liver Transpl 21:1096‐1102, 2015.


The Eurasian Journal of Medicine | 2017

Thymectomy in Myasthenia Gravis

Yener Aydin; Ali Bilal Ulas; Vahit Mutlu; Abdurrahim Colak; Atilla Eroglu

In recent years, thymectomy has become a widespread procedure in the treatment of myasthenia gravis (MG). Likelihood of remission was highest in preoperative mild disease classification (Osserman classification 1, 2A). In absence of thymoma or hyperplasia, there was no relationship between age and gender in remission with thymectomy. In MG treatment, randomized trials that compare conservative treatment with thymectomy have started, recently. As with non-randomized trials, remission with thymectomy in MG treatment was better than conservative treatment with only medication. There are four major methods for the surgical approach: transcervical, minimally invasive, transsternal, and combined transcervical transsternal thymectomy. Transsternal approach with thymectomy is the accepted standard surgical approach for many years. In recent years, the incidence of thymectomy has been increasing with minimally invasive techniques using thoracoscopic and robotic methods. There are not any randomized, controlled studies which are comparing surgical techniques. However, when comparing non-randomized trials, it is seen that minimally invasive thymectomy approaches give similar results to more aggressive approaches.


Interactive Cardiovascular and Thoracic Surgery | 2017

A biomechanical study of 4 different sternum closure techniques under different deformation modes

Suleyman Nazif Orhan; Mehmet H. Özyazıcıoğlu; Abdurrahim Colak

OBJECTIVES This study experimentally compares the efficiency of the 4 most preferred sternal closure tehniques, in 3 different deformation modes of the chest. METHODS Polyurethane sternum models fixed by conventional wiring, steel band, ZipFix band and figure-8 wiring are tested statically under lateral distraction, longitudinal shear and torsional deformation modes. As a result, load-deformation curves are obtained. The closure efficiency of the techniques is then compared with respect to allowable load (corresponding to 2 mm displacement), rigidity, rupture load and rupture displacement. A comparison in terms of cost and ease of application has also been presented. RESULTS The highest allowable load and rigidity values in simple tension and longitudinal shear are obtained by the steel and ZipFix band techniques, respectively. In torsion mode, the highest allowable load is provided by the ZipFix band and the highest rigidty is attained by the steel band technique. The highest rupture loads under simple tension, longitudinal shear and torsion modes are observed in ZipFix, steel band and conventional wiring, respectively. Steel band closure provides the least rupture displacement in simple tension as well as torsion, whereas ZipFix bands give the smallest rupture displacements in longitudinal shear. However, in every loading mode there were no statistically significant differences in allowable load, rigidity and rupture load values between the closure methods, and only rupture displacement values were statistically different for each method. CONCLUSIONS Our results showed that conventional wiring is the most advantageous closing method when compared to the others.


Joint Bone Spine | 2014

Dissection of superior mesenteric artery associated with Behcet's disease

Hayri Ogul; Berhan Pirimoglu; Abdurrahim Colak; Mecit Kantarci

Joint Bone Spine - In Press.Proof corrected by the author Available online since vendredi 28 fevrier 2014


Sakarya Medical Journal | 2012

Pulmoner, perikardial ve hepatik kist hidatikte tek basamak transtorasik operasyon

Yener Aydin; Abdurrahim Colak; Necip Becit; Atila Turkyilmaz; Atilla Eroglu

Ülkemiz kist hidatik için endemik bir bölgedir. Echinococcus granulosus en sık karaciğer ve akciğer olmak üzere tüm organları tutabilmektedir. Olguların yaklaşık üçte birinde multipl organ tutulumu görülmektedir. Multipl kist hidatiğin cerrahi tedavisinde zorluklarla karşılaşılabilmekte ve birkaç seans cerrahi işlem gerekebilmektedir. Bu çalışmada tek basamakta transtorasik yaklaşım ile cerrahi uyguladığımız sağ akciğer, perikardial ve karaciğer kist hidatikli bir olguyu sunduk.


Brazilian Journal of Cardiovascular Surgery | 2018

Application of Circular Patch Plasty (Dor Procedure) or Linear Repair Techniques in the Treatment of Left Ventricular Aneurysms

Ugur Kaya; Abdurrahim Colak; Necip Becit; Münacettin Ceviz; Hikmet Koçak

Objective The aim of this study was to evaluate early clinical outcomes and echocardiographic measurements of the left ventricle in patients who underwent left ventricular aneurysm repair using two different techniques associated to myocardial revascularization. Methods Eighty-nine patients (74 males, 15 females; mean age 58±8.4 years; range: 41 to 80 years) underwent post-infarction left ventricular aneurysm repair and myocardial revascularization performed between 1996 and 2016. Ventricular reconstruction was performed using endoventricular circular patch plasty (Dor procedure) (n=48; group A) or linear repair technique (n=41; group B). Results Multi-vessel disease in 55 (61.7%) and isolated left anterior descending (LAD) disease in 34 (38.2%) patients were identified. Five (5.6%) patients underwent aneurysmectomy alone, while the remaining 84 (94.3%) patients had aneurysmectomy with bypass. The mean number of grafts per patient was 2.1±1.2 with the Dor procedure and 2.9±1.3 with the linear repair technique. In-hospital mortality occurred in 4.1% and 7.3% in group A and group B, respectively (P>0.05). Conclusion The results of our study demonstrate that post-infarction left ventricular aneurysm repair can be performed with both techniques with acceptable surgical risk and with satisfactory hemodynamic improvement.


The Eurasian Journal of Medicine | 2017

Surgical Management of Aortic Coarctation from Infant to Adult

Ugur Kaya; Abdurrahim Colak; Necip Becit; Münacettin Ceviz; Hikmet Koçak

Objective In the present study, we aimed to retrospectively investigate the early and late results of different surgical treatment techniques applied in different age groups with coarctation of the aorta (CoA). Materials and Methods Between January 2007 and February 2017, 26 patients (12 males, 14 females; mean age: 12.2±12.4 years; range: 29 days-34 years) who underwent surgery with the diagnosis of CoA were evaluated. Overall, 11 of these patients (42.3%) were in the infantile period, whereas 15 patients (57.7%) aged between 6 and 34 years. Resection and end-to-end anastomosis were performed in 13 patients (50%). Bypass grafting was performed in six patients (23.1%), and patch plasty was performed in seven patients (26.9%). Results A patient (3.8%) who was operated on during the infantile period died early, whereas another patient (3.8%) died 2 years after the surgery. Recoarctation was detected in two patients. A patient underwent balloon dilatation, whereas another patient underwent balloon dilatation and stenting. In patients who underwent re-section and end-to-end anastomosis based on postoperative echocardiography results during follow-up, a lower statistically significant gradient was observed compared with the preoperative period. Despite the decrease in the left ventricular systolic diameter (LVSD) and the increase in the ejection fraction (EF) the decrease in LVSD and increase in EF were not statistically significant. In patients who underwent patch plasty or graft interposition, the low values of the gradient and left ventricular diastolic diameter in the postoperative follow-up were statistically significant. However, the decrease in LVSD and increase in EF were not statistically significant. Conclusions Our clinical experience suggests that repairing with resection and end-to-end anastomosis is a more appropriate treatment option during the infancy, whereas patch plasty or bypass grafting may be preferred in advanced ages.


The Eurasian Journal of Medicine | 2017

Endovascular Stent Graft Repair of Localized Acute Aortic Intramural Hematoma: A Case Report and Literature Review

Ugur Kaya; Abdurrahim Colak; Necip Becit; Münacettin Ceviz; Hikmet Koçak

Aortic intramural hematoma (IMH) is a variant of acute aortic syndrome, which can be life-threatening. Ascending aorta IMHs, particularly accompanied by penetrating aortic ulcer (PAU), can cause dissection, rupture, and cardiac tamponade. Therefore, early surgical treatment is recommended for IMHs of the ascending aorta. Herein, we present the case of a 60-year-old male patient who was on warfarin sodium treatment and in whom an IMH localized to the arcus aorta was detected incidentally via computed tomography, with the suspicion of pulmonary embolism, and an endovascular stent graft was inserted into the arcus aorta. This case highlights the importance of following ulcerated aortic plaques and suggests that IMH can be successfully treated with endovascular stent grafting.

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