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Background: The incidence of infection in patients on chronic hemodialysis in higher than that of the general population. Infection is known to be a major cause of morbidity and mortality in these patients. The vascular access is important for hemodialysis, but infection through this route is the most common source of bacteremia and can be lethal to the patients. Despite the high morbidity and mortality of bacteremia in patients on chronic hemodialysis, the clinical characteristics of bacteremia in hemodialysis patients is rarely reported yet in Korea.Methods: We included 696 hemodialysis patients from January 1993 to December 2003 at Uijongbu St. Mary's Hospital. We investigated incidence, source, causative organisms, clinical manifestations, complication, and mortality of bacteremia. We compared clinical factors, morbidity, and mortality between arteriovenous fistula and central venous catheter groups.Results: Total 52 cases of bacteremia occurred in 43 patients. The major source of infection was vascular access(48%).Staphylococcus aureuswas most common organism isolated. Major complications were septic shock(9.6%), pneumonia(9.6%), infective endocarditis(3.8%), and aortic pseudoaneurysm(1.9%). Nine patients died from septic shock(n = 4), aspiration pneumonia(n = 2), hypoxic brain injury(n = 1), gastrointestinal bleeding(n = 1), and rupture of aortic pseudoaneurysm. The central venous catheter group(n = 22) had higher incidences of vascular access as a source of infection(81.8% vs 23.3%, p < 0.001) and staphylococcus as a causative organism(77.2% vs 50.0%, p = 0.042) than the arteriovenous group.Conclusion: This data shows that bacteremia causes high incidence of fatal complications and mortality. Therefore, careful management of vascular access as well as early detection of bacteremia is an important factor for the prevention of infection and proper antibiotic therapy should be started early. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate efficacy of percutaneous transluminal angioplasty(PTA) in non-maturing Brescia-Cimino fistulas.Methods: Between January 1997 and December 2003, we treated 22 patients with non-maturing Brescia-Cimino fistulas by PTA. Retrospective analysis was performed on the findings of fistulogram, techniques and success rate of PTA, and patency rate.Results: Seventeen segmental stenoses and 5 segmental occlusions of cephalic veins were identified. Sixteen stenoses and 2 occlusions were located at the cephalic vein adjacent to the anastomosis site, and 3 occlusions and 1 stenosis were seen at the proximal vein near the elbow joint. In addition to venous stenosis, a focal arterial stenosis at the anastomosis site and two accompanying accessory veins that might hamper maturation of main cephalic vein was seen in each of two patients, respectively. Simultaneous occlusion of left innominate vein as well as occlusion of cephalic vein were noted in one patient. Initial success rate of PTA was 95.5%(21/22). Overall success rate including 11 additional PTAs performed during follow-up was 96.9%(32/33). No major complication occurred. Primary and secondary patency rates were 72% and 95% at 3 months, and 50% and 77% at 6 months, respectively.Conclusion: PTA is an effective and safe method in salvaging non-maturing Brescia-Cimino fistulas. [ABSTRACT FROM AUTHOR]

Background: Because of high incidence of acquired renal cyst and renal malignancy, it is suggested that spontaneous renal rupture more frequently occurs in patients receiving long-term hemodialysis than in the general population. This study was performed to evaluate the clinical characteristics of spontaneous renal rupture in hemodialysis patients.Methods: This retrospective study enrolled 12 hemodialysis patients who developed spontaneous renal rupture. We investigated primary renal disease, duration of dialysis, clinical symptoms and signs, radiologic findings, treatment modalities, and histologic findings.Result: The mean age of the patients was 54 ± 10 years old and the number of male was 9. Primary renal disease consisted of autosomal dominant polycystic kidney disease(PCKD)(n = 5), chronic glomerulonephritis(n = 2), diabetic nephropathy(n = 1), hypertensive nephropathy(n = 1), unknown cause(n = 3). Presenting symptoms and signs were sudden onset of flank pain in 9 patients and gross hematuria with mild flank pain in 3 patients. Mean duration from initiation of hemodialysis to development of spontaneous renal rupture was 53 ± 36 months. Abdominal computed tomography showed subcapsular or perinephric hematoma in all patients. Of the 7 non-PCKD patients, 6 patients had multiple acquired renal cysts. Surgical exploration was undertaken in 9 patients. Pathologic examination demonstrated small sized renal cell carcinoma in 2 of 9 patients. Three patients were only treated with conservative management including blood transfusion. All 12 patients recovered without recurrence.Conclusion: This study demonstrated that genetic or acquired renal cyst was an important cause of spontaneous renal rupture in hemodialysis patients and presenting manifestations were sudden onset of flank pain and gross hematuria. [ABSTRACT FROM AUTHOR]

Purpose: To report our initial experience of using cutting balloons angioplasty in the treatment of resistant venous stenoses of Brescia-Cimino fistulas.Materials and Methods: Forty-eight patients with Brescia-Cimino fistulas underwent percutaneous transluminal angioplasty(PTA) of 62 venous stenoses. Of these 48 patients, we encountered 8 venous stenoses(8/62, 12.9%) in 7 patients that were not successfully dilated with 6–8 mm high-pressure balloons inflated up to 24 atm. In each of 8 stenoses, peripheral cutting balloons with diameters of 5–8 mm were employed to dilate resistant stenoses.Results: The locations of stenoses were 3 at the surgical vein mobilization site(“swing point”), 4 at the cephalic vein downstream from the anastomosis, and 1 at the cephalic arch. The grade of stenosis after high-pressure balloon angioplasty ranged from 57% to 87%(mean, 76%). Cutting balloons expanded completely in all stenoses and the residual stenosis after cutting balloon PTA ranged from 0% to 24%(mean, 7%). Residual stenosis was virtually nonexisistent at the 3 stenoses of“swing point.” A focal rupture with a large hematoma occurred at the cephalic arch stenosis, which was treated by a stent placement. One minimal rupture that did not require any treatment occurred at the stenosis of downstream cephalic vein. No repeat angioplasty has been needed during follow-up period(range, 74–249 days).Conclusion: Our early experience demonstrated that when high-pressure balloons fail to dilate stenoses of Brescia-Cimino fistulas, peripheral cutting balloons with diameters of 5–8 mm can be effectively used to overcome the resistance of stenoses. [ABSTRACT FROM AUTHOR]

Objective: We have reported that intimal hyperplasia, which is the pathologic change of the radial artery, is associated with early failure of arteriovenous fistula(AVF) in hemodialysis(HD) patients( Am J Kidney Dis, 41:422–428, 2003). Intima-media thickness(IMT), which represents the whole thickness of arterial wall, can be easily measured by ultrasonography, unlike intima thickness. This study was performed to investigate the impact of IMT of radial artery on early failure of AVF in HD patients.Methods: Ninety HD patients undergoing radiocephalic AVF operation were included in this study. The AVF was constructed in an end vein–to–side artery fashion at the wrist by one vascular surgeon. During the operation, 10-mm long partial arterial walls were removed with elliptical form for microscopic analysis. Specimens were stained with trichrome and examined by a pathologist blinded to the clinical data. AVF patency was prospectively followed up for 1 year after the operation.Results: Mean age of the patients was 56 ± 13 years and the number of females was 44(48.9%). Mean IMT was 430 ± 132 μm(133–760 μm). Of the total 90 patients, 31 patients(34.4%) had AVF failure within 1 year after the operation. Mean IMT was higher in the failed group(n = 31) than in patent group(n = 59)(486 ± 130 μm vs. 330 ± 178 μm, p = 0.004). Using a threshold of 500 μm of IMT, AVF patency rate was compared between these two groups using Kaplan-Meier method with log rank test. The AVF patency rate within 1 year after the operation was higher in patients with IMT ≥ 500 μm(n = 26) than in patients with IMT < 500 μm(n = 64)(p < 0.001). The patients with IMT ≥ 500 μm were older and had higher incidence of diabetes mellitus, compared to the patients with IMT < 500 μm. There was no difference in sex, smoking, hypertension, total cholesterol and albumin levels between the two groups.Conclusion: Our data suggest that increased intima-media thickness of radial artery is associated with early failure of radiocephalic arteriovenous fistula in hemodialysis patients. [ABSTRACT FROM AUTHOR]

Background: Central venous stenosis in chronic hemodialysis patients occurs in about 17% of all venous stenosis and it is associated with central vein catheterization. We evaluated the effect of percutaneous angioplasty and stenting in the treatment of central venous stenosis in hemodialysis patients.Methods: We retrospectively investigated the medical records of a total of 31 dialysis patients who had central venous stenosis. We reviewed the causes of central venous stenosis, clinical manifestations, venographic findings, and patency rate of radiological intervention.Results: Of the total 31 patients, 28 patients had past history of central vein catheterization ipsilateral to vascular access. Mean duration of the catheterization was 32 ± 14 days. Venography showed complete obstruction of central vein(n = 14) and stenosis(n = 17). The site of venous lesion was right subclavian vein(n = 11), innominate vein(n = 9), left subclavian vein(n = 7), and superior vena cava(n = 14). A total of 30 procedures of angioplasty with or without stenting were performed in 26 of 31 patients. Initial success rate was 96.1% and there was no severe complication such as rupture or bleeding. The primary patency rate at 6, 12, 24, and 48 months after the procedure was 87.3%, 75.6%, 67.9%, and 65.4%, respectively. The cumulative patency rate at the same time point was 96.0%, 90.6%, 74.0%, and 72.8%, respectively.Conclusion: Our data suggest that angioplasty with or without stenting is safe and effective in the treatment of central venous stenosis in hemodialysis patients. [ABSTRACT FROM AUTHOR]

Objective: Dialysis adequacy indexed by Kt/V in hemodialysis(HD) patients is recommended as a single pool Kt/V at least 1.2 per session thrice weekly. But many patients cannot achieve this adequacy target. Although dialysis time is the most important factor influencing Kt/V, it is difficult to prolong dialysis time in practice because of its economic impact and poor patient compliance. This study was performed to investigate the effect of increasing dialysis needle size on dialysis adequacy in HD patients.Methods: This study enrolled 73 patients receiving HD thrice weekly for more than 3 months with arteriovenous fistula(AVF) or graft in a single center. Dialysis blood flow rate was 200 ml/min in 12 patients, 250 ml/min in 32 patients, and 300 ml/min in 29 patients. Surface area of dialyzer was 1.2 m2 in 56 patients and 1.6 m2 in 17 patients. We first performed HD using a 16-gauge needle. Then we increased needle size up to 15-gauge without change of any other dialysis conditions such as blood and dialysate flow rates, dialysis time, or distance between needle insertion sites. We compared compression time after removing the needles, venous dialysis pressure(VDP), Kt/V, and urea reduction ratio(URR) between these two methods.Results: The mean age was 54 ± 13 years and the number of patients with diabetes mellitus was 27(37%). Fifty-eight patients(79.5%) have native AVF. Mean Kt/V at HD method using a 15-gauge needle was higher than at HD method using a 16-gauge needle(1.30 ± 0.18 vs. 1.23 ± 0.18, p < 0.001). URR at HD method using a 15-gauge needle was also higher than at HD method using a 16-gauge needle. In contrast, VDP at HD method using a 15-gauge needle was lower than at HD method using a 16-gauge needle(88 ± 22 mmHg vs. 118 ± 28 mmHg, p < 0.001). There was no difference in compression time between the two methods.Conclusion: This study suggests that increasing dialysis needle size is a safe and effective method in improving dialysis adequacy without increasing blood flow rate or dialysis time. [ABSTRACT FROM AUTHOR]