Fatih Boyvat
Başkent University
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Featured researches published by Fatih Boyvat.
European Journal of Radiology | 2004
Cuneyt Aytekin; Fatih Boyvat; Mahmut Can Yağmurdur; Gokhan Moray; Mehmet Haberal
OBJECTIVE To evaluate the efficacy of stent placement for treating upper extremity central venous obstruction in chronic hemodialysis patients. METHODS AND MATERIAL Between January 1999 and October 2001, we inserted metallic stents into the upper extremity central veins of 14 patients with shunt dysfunction and/or arm swelling. The indications for stent placement were stenosis or occlusion of the central vein in the upper extremity used for dialysis. Six of the individuals were diagnosed with subclavian vein stenosis, and 5 with brachiocephalic vein stenosis. Of the remaining 3 patients, 2 had subclavian vein occlusion, and 1 had left brachiocephalic vein occlusion. RESULTS All the stent placement procedures were technically successful, and there were no major complications. Follow-up ranged from 2 weeks to 29 months. The 1-, 3-, 6- and 12-month primary stent patency rates were 92.8, 85.7, 50 and 14.3%, respectively. Repeat interventions, including percutaneous transluminal angioplasty and additional stent placement, were required in 9 patients. The 3-, 6-, 12-month, and 2-year assisted primary stent patency rates were 100, 88.8, 55.5 and 33.3%, respectively. CONCLUSION Endovascular stent placement is an effective alternative to surgery in patients with shunt dysfunction due to obstruction of an upper extremity central vein. Repeated interventions are usually required to prolong stent patency.
European Journal of Radiology | 2001
Cuneyt Aytekin; Fatih Boyvat; Aydın Kurt; Zeynel Yologlu; Mehmet Coskun
A case of portal vein thrombosis (PVT) secondary to pancreatitis is presented. Patient was treated with catheter-directed thrombolysis using urokinase solution. Because the percutaneous transhepatic approach is associated with higher risk of hemorrhage we used the catheter-directed thrombolysis via the transjugular intrahepatic access to restore the patency of the thrombosed portal vein. This case shows that catheter-directed thrombolysis with transjugular approach can be effectively used in the treatment of PVT.
Transplantation Proceedings | 2011
S. Aktas; Fatih Boyvat; S. Sevmis; Gokhan Moray; H. Karakayali; Mehmet Haberal
PURPOSE Despite medical and surgical advances, vascular complications remain common after renal transplant, occurring among 3%-15% of patients. These complications may compromise graft function. This study sought to evaluate the frequency and management of vascular complications after renal transplant. MATERIALS AND METHODS We retrospectively analyzed the 1843 transplantations performed at 2 centers by our team since November 1975. The 1349 male and 494 female patients had an overall mean age of 31.5±11.2 years; (range, 3-66). Grafts were obtained from a living-related donor in 1406 (76.29%) or a deceased donor in the remaining 437 (23.71%). The mean donor age was 40.7±13.7 years (range, 2-76). Of 1843 transplants, multiple vascular anastomoses were performed in 155 cases (8.4%), including 130 involving renal arteries and 25 renal veins. RESULTS Forty-seven vascular complications (2.55%) were observed in 43 procedures (2.33%), most frequently renal artery stenosis (n=14). It was followed by allograft renal artery kinking (n=7), renal vein kinking (n=7), renal artery thrombosis (n=5), renal vein laceration (n=4), renal artery laceration (n=3), renal vein thrombosis (n=2), renal artery disruption (n=2), renal and iliac vein obstructions owing to pressure from a lymphocele (n=1), renal artery and vein obstruction owing to pressure from a hematoma (n=1), or an arteriovenous fistula after percutaneous graft biopsy (n=1). Fifteen of these 47 complications were treated by interventional radiologic procedures. CONCLUSION The vascular complication rates in our patients were somewhat lower than those reported in the literature. A thorough understanding of how complications impair allograft function and survival is essential for adequate treatment. Interventional radiology is invaluable in the postoperative management of transplant-related complications.
European Journal of Radiology | 2009
Erkan Yildirim; Ismail Kirbas; Ali Harman; Umut Ozyer; H. Gurkan Tore; Cuneyt Aytekin; Fatih Boyvat
PURPOSE We present our 7-year experience with coaxial computed tomography (CT)-guided cutting needle lung biopsy and evaluate the factors affecting risk of complications. MATERIAL AND METHOD Between June 2000 and March 2007, we performed 225 CT-guided coaxial lung biopsies in 213 consecutive patients (161 men, 52 women). Lesion size, lesion depth, lesion location, needle-pleural angle, presence of pleural effusion, patients position, and complications secondary to biopsy procedure (pneumothorax and bleeding) were noted. Pneumothorax was graded as mild, moderate, and severe. Bleeding complications were graded as mild, moderate, and severe. RESULTS Two hundred twenty-five biopsy procedures were performed in 213 patients. The mean diameter of the lung lesion was 41.3+/-20.1mm. The mean distance from the peripheral margin of the lesion to the pleura was 17.3+/-19.2mm. After 225 procedures, there were 42 mild (18.6%), 13 moderate (5.7%), and 4 severe (1.7%) pneumothoraxes. Small hemoptysis occurred in 27 patients (12%), and mild parenchymal hemorrhage occurred in 2 patients (0.8%). The overall complication rate was 39.1%. Although, a statistically significant correlation was found between female sex, presence of emphysema, lesion depth, and pneumothorax, none of these factors had a predictive value for pneumothorax. Although, statistically significant correlations were found between female sex, lesion size, and bleeding, only lesion size had a predictive value for bleeding. CONCLUSION The most frequent and important complications of this procedure are pneumothorax and bleeding. But any factor is the predictor of pneumothorax and lesion depth is a poor predictor of bleeding complication.
CardioVascular and Interventional Radiology | 2007
Cuneyt Aytekin; Fatih Boyvat; Ali Harman; Umut Ozyer; T. Colak; Mehmet Haberal
The purpose of this study was to evaluate the long-term outcome of percutaneous therapy of ureteral complications after renal transplantation. Between January 2000 and June 2006 we percutaneously treated 26 renal transplant patients with ureteral obstruction (n=19) and leak (n=7). Obstructions were classified as early (<2 months after transplantation) or late (>2 months). Patients with leak were treated with nephro-ureteral catheter placement and subsequent double-J stenting. Balloon dilatation, stent placement, and basket extraction were used to treat ureteral obstructions. Patients were followed with ultrasonography. No major procedure-related complication occurred. The mean follow-up time was 34.3 months (range: 6 to 74 months). Initial clinical success was achieved in all 19 patients with obstruction and 6 of 7 patients with leak. Four of 9 early obstructions and 4 of 10 late obstructions recurred during the follow-up. All recurrences were initially managed again with percutaneous methods, including cutting balloon technique and metallic stent placement. Although there was no recurrence in patients with successfully treated leak, stricture was seen at the previous leak site in two patients. These strictures were also successfully managed percutaneously. We conclude that in the treatment of ureteral obstruction and leak following renal transplantation, percutaneous therapy is an effective alternative to surgery. However, further interventions are usually needed to maintain long-term patency.
European Radiology | 1999
Mehmet Coskun; Fatih Boyvat; Ahmet Muhtesem Agildere
Abstract. We report a case of surgically retained pericardial sponge as a cause of paracardiac mass in a woman who had thoracotomy 3 weeks prior for replacement of mitral valve prosthesis. Computed tomography examination showed a thin-walled mass containing relatively high-density material in the central part with low-density rim at the periphery suggesting a haematoma with clot formation at first. Surgically removed mass was a retained sponge between right atrium and pericardium. Gossypiboma should be included in the differential diagnosis of an intrathoracic mass besides haematoma and abscess formation in any patient who has had previous thoracotomy.
American Journal of Roentgenology | 2009
Umut Ozyer; Ali Harman; Erkan Yildirim; Cuneyt Aytekin; Feza Karakayali; Fatih Boyvat
OBJECTIVE The objective of our study was to report and compare long-term results of percutaneous transluminal angioplasty and stenting of central venous obstruction in hemodialysis patients. MATERIALS AND METHODS Hemodialysis patients who underwent successful endovascular treatment of central venous obstruction were retrospectively evaluated. Stenotic lesions greater than 50% or inducing extremity swelling were subject to treatment. The primary treatment was angioplasty, and stent placement was accomplished in angioplasty-resistant obstructions. Angioplasty was the primary treatment of recurrence after stent placement. Additional stenting was reserved for angioplasty-resistant recurrences. RESULTS One hundred forty-seven veins in 126 patients (63 males, 63 females) between 15 and 82 years old primarily underwent 101 angioplasties and 46 stent placements. The mean follow-up was 22.1 +/- 16.3 (SD) months. The average number of interventions per vein in the stent group (2.7 +/- 2.4 interventions) was significantly higher than that in the angioplasty group (1.5 +/- 1.0 interventions). Primary patency was significantly higher in the angioplasty group (mean, 24.5 +/- 1.7 months) than that in the stent group (mean, 13.4 +/- 2.0 months). Assisted primary patency of the angioplasty group (mean, 31.4 +/- 2.0 months) and that of the stent group (mean, 31.0 +/- 4.7 months) were equivalent. The overall mean primary patency was 21.1 +/- 1.4 months, and the overall mean assisted primary patency was 31.7 +/- 2.5 months. There were no significant differences in patency rates with regard to patient sex, the type of stent used, the vein or veins treated, or the type of lesions. CONCLUSION Endovascular treatment of central venous obstruction is a safe and effective procedure in hemodialysis patients. Stenting has a significantly lower primary patency rate than angioplasty but adds to the longevity of vein patency in angioplasty-resistant lesions; therefore, stent placement should be considered in angioplasty-resistant lesions.
International Journal of Urology | 2006
Feza Karakayali; S. Sevmis; Ibrahim Ayvaz; Ilteris Tekin; Fatih Boyvat; Gokhan Moray
Abstract Extracorporeal shock wave lithotripsy (ESWL) is considered the standard treatment for most renal and upper ureteral stones. Some centers use ESWL to treat bile duct stones and pancreatic calculi. Although ESWL is generally considered safe and effective, major complications, including acute pancreatitis, perirenal hematoma, urosepsis, venous thrombosis, biliary obstruction, bowel perforation, lung injury, rupture of an aortic aneurysm and intracranial hemorrhage, have been reported to occur in less than 1% of patients. Here, we present an extremely rare case of acute necrotizing pancreatitis occurring after ESWL for a right‐sided urinary stone, which was treated by non‐operative percutaneous interventions.
Acta Radiologica | 1999
Mehmet Coskun; Fatih Boyvat; B. Bozkurt; Ahmet Muhtesem Agildere; E. A. Niron
Purpose: To evaluate thoracic CT findings of long-term hemodialysis patients. Material and Methods: Thoracic CT findings of 117 uremic patients (61 men, 56 women) with complaints of cough, dyspnea, low-grade pyrexia, malaise, weight loss, and profuse perspiration were retrospectively documented. Results: Atelectasis (60%), cardiomegaly (60%), pleural effusion (51%), vascular congestion (44%), parenchymal consolidation (38%), parenchymal scarring-fibrosis (31%), and lymphadenopathy (29%) were the most common CT findings in the thoraces of the long-term hemodialysis patients. Staphylococcus aureus was detected in 13 patients (11%) who had parenchymal infiltration. Thoracic tuberculosis was identified in 15 patients (13%), 11 of these cases being confined to the lung parenchyma, 3 to the pleura, and 1 involving the pleura and pericardium. Conclusion: In patients under long-term hemodialysis treatment, parenchymal consolidation, secondary to infectious agents such as S. aureus and Mycobacterium tuberculosis, is the most important CT finding since these lesions can be detected and treated successfully if they are considered as etiologic factors early on.
Transplantation Proceedings | 2008
Fatih Boyvat; Cuneyt Aytekin; Ali Harman; Şinasi Sevmiş; H. Karakayali; Mehmet Haberal
Hepatic artery stenosis or thrombosis following liver transplant is a potentially life-threatening complication. Successful liver transplant depends on uncompromised hepatic arterial inflow. Early diagnosis and treatment of complications prolong graft survival. Interventional radiologic techniques are frequently used to treat hepatic artery complications. Twenty patients with hepatic artery stenoses (n = 11) or thromboses (n = 9) were included in this study. Eighteen of the 20 patients were successfully treated by stent placement. In 9 patients, early endovascular interventions were performed 1 to 7 days after surgery. Two patients were operated owing to the effects of dissection and bleeding from the hepatic artery. Repeat endovascular interventions were performed 10 times in 6 patients. Follow-up ranged from 5 months to 4.5 years. Nine patients with patent hepatic arteries died during follow-up owing to reasons unrelated to the hepatic artery interventions. In 3 patients, the stents became occluded at 3, 5, and 9 months after surgery but no clinical symptoms were present.