Azman Ates

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

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).

Prevention of reperfusion injury of the spinal cord in aortic surgery: An experimental study

PurposeWe designed an experimental study to show the effects of some agents in order to prevent reperfusion injury of the spinal cord.MethodsTwenty rabbits were used and were divided into two groups in our study. Infrarenal abdominal aortic occlusion, between renal arteries and iliac bifurcations, was applied to the subjects in group 1 for only 30 min; in the group 2 subjects, on the other hand, intra-aortic diltiazem, N-acetylcysteine, and catalase combinations were applied after infrarenal abdominal aortic occlusion. The spinal cord functions of the subjects were assessed at the 48th hour after the operation according to Tarlov scoring, then cord tissue samples were taken for biochemical and histopathological studies.ResultsThe group 2 subjects had better neurological functions than group 1 subjects (P < 0.01). In group 2; superoxide dismutase and glutathione peroxidase levels increased, while malondialdehyde and xanthine oxidase levels decreased as compared with group 1 (P < 0.05). A histopathological examination showed the group 2 samples to have fewer bleeding points and less neuron loss.ConclusionsWe concluded that antioxidant agent combinations (diltiazem, N-acetylcysteine, and catalase) applied after ischemia might thus help protect the spinal cord against ischemia and reperfusion injury.

Effects of Ascorbic Acid, Alpha-Tocopherol and Allopurinol on Ischemia-Reperfusion Injury in Rabbit Skeletal Muscle: An Experimental Study

Purpose Ischemia reperfusion injury to skeletal muscle, following an acute arterial occlusion is important cause of morbidity and mortality. The aim of the present study was to determine and evaluate the effects of ascorbic acide, alpha-tocopherol and allopurinol on ischemia reperfusion injury in rabbit skeletal muscle. Methods Forty-eight New Zealand white rabbits, all male, weighing between 2.5 to 3.0 (mean 2.8) kg, were used in the study. They were separated into four groups. Group I was the control group without any drugs. The other groups were treatment groups (groups II, III, and IV). Group II rabbits administrated 50 mg/kg ascorbic acide and 100 mg/kg alpha-tocopherol 3 days prior to ischemia, group III rabbits received 50 mg/kg allopurinol 2 days prior to ischemia, and group IV rabbits were administrated both 50 mg/kg ascorbic acide, 100 mg/kg alpha-tocopherol 3 days prior to ischemia and 50 mg/kg allopurinol 2 days prior to ischemia. Two hours ischemia and 2 hours reperfusion were underwent to the treatment groups. At the end of the reperfusion periods, muscle samples were taken from rectus femoris muscle for determination of superoxide dismutase, catalase and glutathione peroxidase activities as antioxidant enzymes, and malondialdehyde as an indicator of lipid peroxidation and xanthine oxidase levels as source hydroxyl radical. Besides, histopathological changes (edema, inflammation, ring formation and splitting formation) were evaluated in the muscle specimens. Results In the treatment groups; superoxide dismutase (U/mgprotein), catalase (U/mgprotein), and glutathione peroxidase (U/mgprotein) levels increased, malondialdehyde (nmol/mgprotein) and xanthine oksidase (mU/mgprotein) levels decreased compared to control I (p < 0.05). Increase of superoxide dismutase, catalase, and glutathione peroxidase levels were the highest and decrease of malondialdehyde and xanthine oxidase levels were the highest in group IV compared to groups II and III, but no significant as statistically. Also amount of cellular injury in group II, III, and IV were lower than group I. Conclusions Antioxidant medication may help lowering ischemia reperfusion injury. In our study, all drug medications are shown to be able to have an effective role for preventing ischemia reperfusion injury. Moreover, ascorbic acide + alpha-tocopherol + allopurinol group (group IV) may have a beneficial effect to decrease the local and systemic damage due to ischemia-reperfusion injury.

Ruptured and Non-ruptured Sinus of Valsalva Aneurysms: Five Case Studies

Between 1987 and 2000, we observed retrospectively a series of five cases of surgically treated sinus of Valsalva aneurysms (SVAs) at the Department of Cardiovascular Surgery, Atatürk University, Erzurum, Turkey. The mean age of the five patients was 32.6 years (range, 18–48 years). Three were male and two were female. Aneurysms originated from the right coronary sinus in four patients, and from the non-coronary sinus in one. Three aneurysms fistulized to the right ventricle, one to the right atrium and the last, originating from the right coronary sinus, was non-ruptured. Two aortic insufficiencies, two ventricular septal defects, one patent ductus arteriosus and one left ventricular outlet obstruction were found as concomitant lesions. All cases were symptomatic. Ruptured SVAs were repaired by double approach involving both the chamber and aortic root. There was no late mortality either in the hospital or during the follow-up period (mean 40.4 months, range 13–66 months). No patient required re-operation.

Time and risk analysis for acute type A aortic dissection surgery performed by hypothermic circulatory arrest, cerebral perfusion, and open distal aortic anastomosis.

BACKGROUND Hypothermic total circulatory arrest, retrograde or antegrade cerebral perfusion, and open distal anastomosis are important stages of surgical management and cerebral protection for acute type A dissections. Among the factors that influence survival are the transfer time to hospital from the onset of symptoms, in-hospital transfer time to operation, organ malperfusion, preoperative risk factors, and intraoperative variables. The aim of this study was to analyze time and risk factors during surgical management. METHODS Between September 1996 and March 2002, a total of 26 patients with acute type A aortic dissection were operated. Sixteen patients (61.5%) were male and mean age was 49 ( 13.1 years (range: 26-68). The diagnosis was based on clinical examination, telecardiography, transthoracic echocardiography, computerized tomography, and angiography. Hypothermic total circulatory arrest, retrograde or antegrade cerebral perfusion and open distal anastomosis were used during the procedures. Operative techniques were as follows: supracoronary ascending aortic replacement (17 patients), aortic root and ascending aortic replacement with flanged composite grafting technique (5 patients), replacement of ascending aorta and hemiarcus (1 patient), aortic root and ascending aortic replacement with modified Bentall technique (1 patient), replacement of ascending aorta and arcus (1 patient), and total arcus replacement with elephant trunk technique and modified Bentall procedure (1 patient). RESULTS The early postoperative mortality rate within the first 30 days was 26.9%, and the late postoperative mortality rate was 15.8%. Two patients (7.7%) developed major neurological complications during the postoperative period. Time to admission, durations of total circulatory arrest, cross-clamp, cardiopulmonary bypass, and intubation were longer, and postoperative blood loss was greater in patients who died during early postoperative period, although the differences did not reach statistical significance. Duration of total circulatory arrest was longer in patients who developed neurological dysfunction compared to patients without this complication; this difference also did not reach statistical significance. CONCLUSIONS Total circulatory arrest, cerebral perfusion, and open distal anastomosis are reliable options in the surgical management of acute type A aortic dissections. With open distal anastomosis aortic arcus can be evaluated, distal anastomosis can be performed more easily, and postoperative neurological recovery is hastened. In the present study, although statistical significance could not be reached due to limited sample size, the time to admission, durations of total circulatory arrest, cross-clamp, and cardiopulmonary bypass, and the amount of postoperative chest output seem to influence postoperative survival.

Carotid Body Tumors (Paragangliomas)

Carotid body tumors were diagnosed in 19 patients (13 females and 6 males) between 1977 and 2000. All but one were operated upon. The ages of the 18 surgically treated patients ranged from 17 to 65 years. Carotid body tumor was confirmed in 16 cases; the diagnosis was neurofibroma in 1 and tuberculosis lymphadenitis in 1. The carotid body tumors were resected without a shunt procedure. Eight patients underwent total resection, 6 had resection and saphenous vein interposition, 1 had partial resection, and 1 had carotid artery ligation with no resultant neurological deficit. One case of hypoglossal paralysis and one benign ipsilateral recurrence were detected. Contralateral recurrence was detected in 1 patient 4 years postoperatively. No mortality or malignant course was observed.

Role of Closed Mitral Commissurotomy for Mitral Stenosis: Mid- and Long-term Surgical Outcome of 36 Patients

PURPOSE To evaluate long-term survival and valve-related complications as well as prognostic factors for mid- and long-term outcome after closed mitral commissurotomy, covering a follow-up period of 14 years. MATERIAL AND METHODS Between 1989 and 2003, 36 patients (28 women and 8 men, mean age 28.8 +/- 6.1 years) underwent closed mitral commissurotomy at our institution. The majority of patients were in New York Heart Association (NYHA) functional class IIB, III, or IV. Indication for closed mitral commissurotomy was mitral stenosis. Closed mitral commissurotomy was undertaken with a Tubbs dilator in all cases. Median operating time was 2.5 hours +/- 30 minutes. RESULTS After closed mitral commissurotomy, the mitral valve areas of these patients were increased substantially, from 0.9 to 2.11 cm(2). No further operation after initial closed mitral commissurotomy was required in 86% of the patients (n = 31), and NYHA functional classification was improved in 94% (n = 34). Postoperative complications and operative mortality were not seen. Follow-up revealed restenosis in 8.5% (n = 3) of the patients, minimal mitral regurgitation in 22.2% (n = 8), and grade >or=3 mitral regurgitation in 5.5% (n = 2) patients. No early mortality occurred in closed mitral commissurotomy patients. Reoperation was essential for 5 patients following closed mitral commissurotomy; 2 procedures were open mitral commissurotomies and 3 were mitral valve replacements. No mortality occurred in these patients. CONCLUSIONS The mitral valve area was significantly increased and the mean mitral valve gradient was reduced in patients after closed mitral commissurotomy. Closed mitral commissurotomy is a safe alternative to open mitral commissurotomy and balloon mitral commissurotomy in selected patients.

Repair of coarctation of the aorta in adults and hypertension

The aim of this study is to determine if surgical repair of coarctation in adults improves systemic hypertension. The charts of 23 consecutive patients (age range 13-36 years, mean 23.6+/-7) who underwent repair of aortic coarctation at the Atatürk University, Aziziye Hospital, between 1986 and 2000 were reviewed. There were 16 (70%) men and seven (30%) women. All patients had preoperative hypertension. Systolic blood pressure (BP) ranged between 150 and 200 mmHg, with a mean of 176+/-15 mmHg. Peak systolic gradient across the coarctation was 52+/-20 mmHg (range from 30 to 112 mmHg). There were no early or late deaths. Mean systolic BP values at the first postoperative evaluation were 176+/-15 mmHg (p<0.001 from preoperative values). Exercise testing revealed hypertensive response to exercise in three of 10 patients who had borderline hypertension at rest and without medication. Repair of coarctation of aorta even in adults is safe and improves systemic hypertension. To identify patients with potential hypertension, exercise testing should be performed. Impaired arterial dilatation may be an important contributor to exercise-related hypertension and late morbidity or mortality.

Pseudoaneurysm of left ventricular following left ventricular apical venting

Sirs: Left ventricular pseudoaneurysm is a rare complication following transmural myocardial infarction but may also follow chest trauma, inflammatory disease, infective endocarditis, tumors and cardiac surgery [4]. Due to the risk of rupture and death, surgical treatment is recommended when left ventricular pseudoaneurysm is detected [1, 5]. We present a case of pseudoaneurysm of left ventricular following left ventricular apical venting.

The effect of surgical treatment for secundum atrial septal defect in patients more than 30 years old.

BACKGROUND We prospectively examined whether surgical treatment of secundum atrial septal defects in patients 30 years old improves their early- and mid-term clinical outcomes. Our clinical experience is reviewed to assess the importance of surgical management in elderly patients with atrial septal defect. METHODS We analyzed 41 patients older than 30 years of age who underwent surgical correction of a secundum atrial septal defect. To evaluate the effects of surgical treatment, we compared functional capacity, diuretic administration, rhythm status, and echocardiographic parameters of all patients before and after the operation. RESULTS The median follow-up period was 4.2 years (range, 6 months-7 years). There were no operative deaths. Functional class in most of the patients improved after operation. Two patients reverted to normal sinus rhythm after the operation. There was only one new atrial fibrilation among patients in the postoperative term. Right atrial and right ventricular dimensions and pulmonary artery pressures were significantly decreased, and ejection fractions were significantly increased after the operation. The need for diuretic treatment was decreased after surgical repair. No residual intracardiac shunts were identified during follow-up. There were no cerebrovascular thromboembolic accidents in the early postoperative period. CONCLUSION Surgical closure of atrial septal defects in patients over 30 years old can improve their clinical status and prevent right ventricular dilatation and insufficiency. The operation must be performed as soon as possible, even if the symptoms or the hemodynamic impact seem to be minimal.