Ali Firat
Başkent University
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Featured researches published by Ali Firat.
CardioVascular and Interventional Radiology | 2005
Fatih Boyvat; Cuneyt Aytekin; T. Colak; Ali Firat; H. Karakayali; Mehmet Haberal
PurposeTo determine the efficacy of the Memokath 051 stent (Engineers & Doctors, Hornbaek, Denmark) in the treatment of recurrent ureteral stenosis or occlusion in transplant kidneys.MethodsFrom October 1985 through January 2004, 1,131 renal transplantations were performed at our center. Four patients who developed recurrent renal transplant ureter obstruction had nephrostomy catheters placed. Antegrade pyelography showed ureteral stenosis in three cases and complete occlusion in one patient. In each case, a Memokath 051 stent was inserted via an antegrade approach. Mean follow-up was 20 months (range 18–21 months). Creatinine levels were measured and ultrasonography was performed during follow-up.ResultsAll stent procedures were technically successful. During follow-up, one stent migrated within 10 days after stent insertion and was removed cystoscopically. Another stent had to be removed in the 14th month due to resistant infection, and was replaced with a new Memokath 051 stent which remained patent for another 8 months. The other two stents were fully patent at the 18th and 21st month of follow-up, respectively.ConclusionPlacement of a Memokath 051 stent appears to be a promising treatment alternative to balloon dilation, double-J stents and open surgical intervention for ureteral stenosis or occlusion in kidney transplant recipients. Further study of larger series is necessary.
CardioVascular and Interventional Radiology | 2004
Cueneyt Aytekin; Ali Firat; Erkan Yildirim; Ismail Kirbas; Fatih Boyvat
The interventional angiographic techniques using the percutaneous femoral approach for endovascular revascularization are becoming increasingly more popular. These methods usually require larger sheaths, and most patients need postprocedural anticoagulation or antiplatelet therapy. As a consequence, the interventional procedure is associated with a higher rate of complications at the arterial entry site compared to diagnostic angiography [1,2]. The reported incidence of iatrogenic pseudoaneurysm formation after coronary artery interventions ranges from 3.2% [1] to 7.7% [3], and the rates noted after diagnostic angiography range from 0.2% [1] to 1% [4].Peripheral pseudoaneurysms have traditionally been treated by surgical intervention, but nonsurgical alternatives, such as ultrasound (US)-guided compression, coil embolization, stent-graft placement, and percutaneous thrombin injection with or without balloon occlusion have also been documented. Of these alternatives, direct percutaneous embolization with embolic agents is the most popular method. The tissue adhesive n-butyl cyanoacrylate (NBCA) (Hystoacryl) (B. Braun, Melsungen, Germany) is one of the most popular occluding agents for neurovascular interventions, and has been widely used for more than 20 years [5,6]. In this study, we evaluated the efficacy and utility of direct percutaneous injection of NBCA for embolization of femoral pseudoaneurysms.
Abdominal Imaging | 2003
Cuneyt Aytekin; Fatih Boyvat; Ali Firat; Mehmet Coskun; Sedat Boyacioglu
AbstractBackground: The feasibility and efficacy of portacaval shunt creation through the transhepatic and transjugular approach were evaluated in patients with portal hypertension whose hepatic venous anatomies were unsuitable for the standard shunt procedure. Methods: Portacaval shunts were created via percutaneous transhepatic access in six patients. We used snares to target the portal vein and the inferior vena cava. Then a needle was introduced percutaneously and advanced through the snares. A guidewire was advanced through the needle and snared in the inferior vena cava. The wire was then withdrawn through the transjugular sheath. The rest of the procedure was completed in standard fashion. The transhepatic tracts were embolized. Results: The portacaval shunt procedures were successful in all patients. There were no major complications during the procedures, but one patient died of sepsis 1 week later. Two patients developed shunt occlusion, and in one case the shunt was revised successfully. The other patient with occlusion underwent orthotopic liver transplantation. The shunts in the remaining three patients and the revised shunt were patent at 5 to 20 months of follow-up. Conclusion: Direct portacaval shunt creation using the percutaneous transhepatic and transjugular technique is a good alternative when standard portosystemic shunt creation is difficult or impossible.
Rivista Di Neuroradiologia | 2003
A Kurt; Ali Firat; Am Aildere; Cuneyt Aytekin; S Benli; I Özmen; Nurhan Ozdemir; Mehmet Haberal
Compared to the normal population, renal transplant recipients and end-stage renal disease (ESRD) patients on hemodialysis have a higher incidence of white matter changes (WMC) on brain magnetic resonance imaging (MRI). The lesions appear as focal or patchy areas in the periventricular white matter. Both these patient groups are known to be affected by accelerated atherosclerosis, which produces small-vessel disease. This may lead to thromboembolic complications that cause these white matter lesions. This study retrospectively assessed the frequency of MRI-detected WMC in ESRD patients on hemodialysis and kidney recipients, and correlated the rates with hemodialysis duration and post-transplantation interval. Focal and patchy type lesions were distinguished, and the frequencies of these were studied. Also, in the respective groups, comparisons were made among patients with different hemodialysis durations and post-transplantation intervals. The results showed that specifically focal lesions increase in parallel with hemodialysis duration, but there was no statistical relationship between WMC and post-transplantation interval.
Interventional Neuroradiology | 2017
Enes Duman; Fatma Karakoç; H Ulas Pinar; Rafi Dogan; Ali Firat; Erkan Yildirim
Background Cerebral vasospasm (CV) is a major cause of delayed morbidity and mortality in patients with subarachnoid hemorrhage (SAH). Various cerebral protectants have been tested in patients with aneurysmal SAH. We aimed to research the success rate of treatment of CV via intra-arterial milrinone injection and aggressive pharmacological therapy for refractory CV. Methods A total of 25 consecutive patients who received intra-arterial milrinone and nimodipine treatment for CV following SAH between 2014 and 2017 were included in the study. Patients who underwent surgical clipping were excluded. Refractory vasospasm was defined as patients with CV refractory to therapies requiring ≥3 endovascular interventions. Overall, six patients had refractory CV. Long-term neurological outcome was assessed 6–18 months after SAH using a modified Rankin score and Barthel index. Results The median modified Rankin scores were 1 (min: 0, max: 3) and Barthel index scores were 85 (min: 70, max: 100) From each vasospastic territory maximal 10–16 mg milrinone was given to patients; a maximum of 24 mg milrinone was given to each patient in a session and a maximum of 42 mg milrinone was given to a patient in a day. Both milrinone and nimodipine were given to three patients. There was a large vessel diameter increase after milrinone and nimodipine injections. No patient died due to CV; only one patient had motor dysfunction on the right lower extremity. Conclusion Higher doses of milrinone can be used effectively to control refractory CV. For exceptional patients with refractory CV, high dose intra-arterial nimodipine and milrinone infusion can be used as a rescue therapy.
Üroonkoloji Bülteni | 2017
İsmail Okan Yıldırım; Enes Duman; Ali Firat; Hüseyin Çelik; Kaya Saraç
Ad dress for Cor res pon den ce/Ya z›fl ma Ad re si: İsmail Okan Yıldırım MD, İnönü University Faculty of Medicine, Department of Radiology, Malatya, Turkey Phone: +90 422 341 06 60/5707 E-mail: [email protected] ORCID-ID: orcid.org/0000-0002-3641-0103 Re cei ved: 28.11.2017 Ac cep ted: 25.12.2017 Objective: The purpose of this study was to evaluate efficacy outcomes following prostate artery embolization (PAE) for the treatment of benign prostatic hyperplasia (BPH) patients with high comorbidity. Materials and Methods: This retrospective study included 22 patients treated with PAE from May 2015 to June 2017. Patients with Charlson comorbidity index ≥2, International Prostate Symptom Score (IPSS) >12, prostate specific antigen (PSA) levels <4 ng/mL or between 4 and 10 ng/mL with negative prostate biopsy and total prostate volume (TPV) >90 cm3 were included. Total PSA, maximum flow rate (Qmax), TPV, IPSS, post-voiding residual (PVR) values were recorded in all patients in the urology clinic before PAE and at 3 and 6 months after PAE. Results: The average patient age was 73.86±6.25 years and operative time was 80 minutes (range, 60-120 min). Pre-PAE and 6-month post-PAE values were: IPSS: 25.18±6.75 an d 11.27±3.29 (p<0.05), Qmax: 8.31±3.12 and 17.22±3.23 (p<0.05), PVR: 87.9±19.25 and 25.86±7.72 (p<0.05), TPV: 134.45±57.56 and 86±15.4 (p<0.05), and PSA: 3.89±1.26 and 2.11±1.06 (p<0.05). Embolization was performed unilaterally due to atherosclerosis and strictures in the internal iliac artery branches in 2 patients. After the procedure, 2 patients experienced transient hematuria which did not require bladder irrigation, 1 patient had acute urinary retention due to dysuria, and 1 patient had transient hematospermia. Conclusion: PAE may be an alternative treatment method in BPH patients with high comorbidity.
Transplantation | 2004
Ali Firat; Fatih Boyvat; Gokhan Moray; Cuneyt Aytekin; H. Karakayali; Mehmet Haberal
BACKGROUND Splenomegaly and hypersplenism occur in patients with chronic liver disease and liver transplant recipients. The traditional treatment for hypersplenism is surgical removal. Percutaneous interventional methods, such as partial splenic embolization, are alternatives to surgery for hypersplenism. This article gives preliminary findings for a new percutaneous technique in which a narrowed stent is placed in the splenic artery. METHODS The study focused on 10 patients (eight males and two females) who were treated for hypersplenism. Partial splenic embolization was performed in six patients (age range, 1-43 years) who were waiting for liver transplantation, and narrowed stents were placed in four patients (age range, 12-47 years) who had undergone either orthotopic two patients) or heterotopic two patients) liver transplantation. For embolization, the splenic artery was catheterized and polyvinyl alcohol particles were infused to the distal branches, reducing blood flow in the spleen by 40% to 50%. In the other cases, a narrowed stent was deployed to the middle portion of the splenic artery. RESULTS Hypersplenism was successfully treated in all 10 cases. Compared with partial splenic embolization, placement of narrowed stents was associated with lower frequencies of postintervention fever and pain, shorter hospital stay, and decreased need for antibiotics. In addition to treating hypersplenism, narrowed-stent placement also completely resolved splenic artery steal syndrome in the two patients (orthotopic liver transplant recipients) with this condition. CONCLUSION Percutaneous placement of a narrowed stent in the splenic artery is a promising new technique for treating hypersplenism and splenic arterial steal syndrome.
Akademik Gastroenteroloji Dergisi | 2002
Cuneyt Aytekin; Ali Firat; Fatih Boyvat; A. Muhteşem Ağildere; Sedat Boyacioğlu
Surgical removal of malignant liver tumors is considered to be the most effective treatment for liver cancer. However, approximately 70% of patients cannot have this surgery due to the size or location of the tumors or other health factors. These limitations have led to the development of less invasive procedures, including intra-arterial chemoembolization, percutaneous ethanol injection, interstitial laser, microwave and radiofrequency thermal ablation. The most promsing of these new techniques is radiofrequency ablation which has the following advantages over existing conventional therapies: it is an outpatient procedure, is minimally invasive and can be repeated when necessary to treat a residual or recurrent tumor.
Transplantation Proceedings | 2003
Fatih Boyvat; Cuneyt Aytekin; Ali Firat; Ali Harman; H. Karakayali; Mehmet Haberal
Transplantation Proceedings | 2005
Ali Firat; Fatih Boyvat; Gokhan Moray; Cuneyt Aytekin; H. Karakayali; Mehmet Haberal