Postoperative day 1 access blood flow and resistive index can predict patency in distal forearm arteriovenous fistula.

INTRODUCTION: Early access failure is an important complication of autogenous arteriovenous fistulas (AVFs). We prospectively monitored patients who underwent AVF creation using ultrasonography. METHODS: Color flow imaging was used to assess access blood flow in patients undergoing creation of a new AVF in the distal forearm preoperatively and at 1 day and 1 week postoperatively. We measured the flow volume (FV) and resistive index (RI) of the brachial artery, and the internal diameter of the brachial artery and outflow vein. The primary outcome was the primary patency of the AVF without percutaneous angioplasty (PTA) or surgical revision 40 days after access creation. RESULTS: We recruited 35 patients with newly created AVFs (men, 21; mean age, 73 years). Within one day of operation, the overall FV increased from 62 to 352 mL/min (p<0.0001) while the overall RI decreased from 1.0 to 0.63 (p<0.001). Five patients required PTA or surgical revision (intervention group [IG]), whereas 30 patients did not (non-intervention group [NIG]). The FV increased while the RI decreased from day 1 to week 1 in the NIG, but not in the IG (p<0.0001). The diameter of the brachial artery and outflow vein significantly increased in the NIG at 1 week. The FV of 235 mL/min and RI of 0.63 at 1 day were the thresholds for predicting early fistula failure. CONCLUSIONS: Access FV and RI at 1 day after AVF creation can predict primary patency and help plan intervention.

Hypomagnesemia as a predictor of mortality in hemodialysis patients and the role of proton pump inhibitors: A cross-sectional, 1-year, retrospective cohort study.

Introduction This study aimed to evaluate the association between proton pump inhibitor (PPI) use and serum magnesium levels, and the role of hypomagnesemia and PPI use as a risk factor for mortality in hemodialysis patients. Methods An observational study, including a cross-sectional and 1-year retrospective cohort study. The study comprised 399 hemodialysis patients at a single center, and was conducted from January to September 2014. Multiple linear regression analysis was used to investigate the independent relationship between serum magnesium levels and baseline demographic and clinical variables, including PPI and histamine-2 receptor antagonist use. Cox regression model was used to identify lower serum magnesium level and PPI as a predictor of 1-year mortality. Findings Serum magnesium levels were lower with PPI use than non-PPI use (2.39 ± 0.36 vs. 2.56 ± 0.39 mg/dL, P < 0.001). Multiple linear regression analysis showed that PPI use, low serum albumin levels, and low serum potassium and high-sensitivity C-reactive protein (hs-CRP) levels were significantly associated with low serum magnesium levels. A total of 29 deaths occurred during the follow-up period. According to Cox regression analysis stratified by hs-CRP, only high serum hs-CRP levels (>4.04 mg/L) in association with low serum magnesium levels was an independent risk factor for 1-year mortality (hazard ratio: 2.92; 95% CI: 1.53-6.40, P < 0.001). Discussion Serum magnesium levels are lower in PPI use. In the inflammatory state, a low serum magnesium level is a significant predictor of mortality in hemodialysis patients.

Umbilical Hernia in Peritoneal Dialysis Patients: Surgical Treatment and Risk Factors.

No previous reports have focused on surgical treatments and risk factors of umbilical hernia alone in peritoneal dialysis (PD) patients. Herein, we evaluated the treatments and risk factors. A total of 411 PD patients were enrolled. Of the 15 patients with umbilical hernia (3.6%), six underwent hernioplasty. There was no recurrence in five patients treated with tension-free hernioplasty. The mean PD vintage after onset of hernia in the hernioplasty group tended to be longer than that in the non-hernioplasty group. An incarcerated hernia occurred in one non-hernioplasty patient. Although the incidence was significantly higher among women (P = 0.02), female sex was not a risk factor for umbilical hernia (P = 0.08). Our findings suggest that umbilical hernias should be repaired for continuing PD. Furthermore, there were no significant risk factors for umbilical hernia in PD patients. Future studies with larger sample groups are required to elucidate these risk factors.

Modified MILLER banding procedure for managing high-flow access and dialysis-associated steal syndrome.

PURPOSE: Both high-flow vascular access (VA) and dialysis-associated steal syndrome are serious complications requiring a flow reduction technique. We adopted the minimally invasive limited ligation endoluminal-assisted revision (MILLER) banding procedure with some modifications to control the high blood flow and steal syndrome during VA procedures and retrospectively assessed the outcome. METHODS: Seven patients with high-flow access (access flow >1400 ml/min) and five patients with steal syndrome (with pain, coldness, or cyanosis) were treated using the MILLER banding method. Flow volume of the brachial artery was monitored using Doppler ultrasonography during the banding procedure. In patients with steal syndrome, the finger probe of a pulse oximeter was attached to a finger on the ipsilateral side, and the peripheral oxygen saturation (SpO2) was monitored. RESULTS: In the high-flow group, the mean access blood flow (Qa) decreased from 2043 ± 463 ml/min (mean ± SD) to 1248 ± 388 ml/min (p<0.001). In the steal syndrome group, the SpO2 value improved in all steal syndrome patients after banding. Symptoms were almost relieved in two steal syndrome patients. The Qa in the steal group decreased from 997 ± 867 to 548 ± 376 ml/min (p = 0.12). The secondary patency rates of the high-flow and steal groups at 6 months were 83.3% and 50%, respectively. CONCLUSIONS: The MILLER banding procedure with intraoperative access flow monitoring is effective to treat high-flow VA and steal syndrome.

Percutaneous transluminal angioplasty for central venous disease in dialysis patients: influence on cardiac function.

PURPOSE: Increased vascular access flow after percutaneous transluminal angioplasty (PTA) for central venous stenosis and occlusion (central venous disease, CVD) can affect cardiac function in hemodialysis (HD) patients. We evaluated the cardiac function, etiology, and treatment in HD patients with CVD. METHODS: HD patients with CVD treated by PTA between June 2006 and February 2013 were studied. RESULTS: Of the 26 patients, 22 had left arteriovenous fistulas (AVFs), 1 left arteriovenous graft (AVG), 2 right AVFs, and 1 right AVG. CVD sites were the left brachiocephalic vein (LBCV; n=13), left subclavian vein (LSCV; n=7), both LBCV and LSCV (n=3), right BCV (n=2), and right SCV (n=1). Computed tomography findings indicated a high extrinsic compression rate for the LBCV (91%) and LSCV (50%). The success rate of PTA was 96%. The primary patency rates at 3, 6, 9, and 12 months were 81%, 73%, 65%, and 57%, respectively. The post-PTA brachial artery flow volume was significantly increased compared with the pre-PTA volume (1306 vs. 957 ml/min; p=0.005). The post-PTA left ventricular ejection fraction and expiration inferior vena cava diameter were the same as the pre-PTA values (57% versus 60%, p=0.2 and 17 versus 17 mm, p=0.9, respectively). CONCLUSIONS: Our findings suggest that increased vascular access flow after PTA for CVD has no relation to cardiac function.

Morning blood pressure is useful for detection of left ventricular hypertrophy in hemodialysis patients.

BACKGROUND: When diagnosing hypertension (HT) it is essential to determine not only the level of raised blood pressure (BP), but also how the condition relates to organ damage. The best time to measure BP for diagnosing HT in patients on hemodialysis (HD) remains unclear. METHODS: A total of 100 HD patients (mean age 63.8 years, 60 males) were studied. Left ventricular hypertrophy (LVH) was detected by echocardiography and BP monitored for 1 week at 20 different times in the morning and night, before and after dialysis. We also checked for masked HT, i.e., patients with weekly morning HT, but not pre-dialysis HT. RESULTS: Average BP for the week was 141.9 ±19.0/79.6 ± 10.6 mmHg, with 68 patients classified as hypertensive. Average morning BP was 144.6 ± 19.8/81.7 ± 11.3 mmHg, and 71 patients had weekly morning HT. In addition, 62 patients had LVH and 51 patients had relative morning HT. Multiple logistic analyses showed that LVH was associated with weekly morning HT, morning HT on HD and non-HD days, average HT, and relative morning HT. However, evening, pre-dialysis, and post-dialysis HT showed no association with LVH. Masked HT was found in 20 % of patients. If HT had been diagnosed using only pre-dialysis BP, 20 of the 71 patients with weekly morning HT would not have been detected. CONCLUSION: Morning BP is useful for detecting LVH in HD patients. Monitoring of morning BP may be superior to measurements taken at other times for diagnosing HT.

Bone mineral density may be related to atherosclerosis in hemodialysis patients.

Biological interactions between the bone and the blood vessels are gradually being clarified. To investigate the relationship between bone mineral density and atherosclerosis in hemodialysis patients, we examined the bone mineral density and the intima-media thickness of the carotid artery in 83 dialysis patients with non-diabetic nephropathy (44 men and 39 women) aged from 23 to 83 years. The duration of hemodialysis ranged from 2 to 344 months. The bone mineral density of the radius was measured by dual-energy X-ray adsorptiometry, and the ratio of this value to the standard value for the same age and gender was calculated ( Z-score). As an index of atherosclerosis, the intima-media thickness of the carotid artery was measured by high resolution B-mode ultrasonography. Then the relationship between the Z-score and various factors was examined using Spearman's rank correlation analysis and multiple regression analysis. The Z-score showed a negative correlation with the duration of hemodialysis, the carotid intima-media thickness, and the levels of alkaline phosphatase, intact parathyroid hormone, and low-density lipoprotein cholesterol by Spearman's rank correlation analysis. In addition, the Z-score showed a positive correlation with the lipoprotein (a) level and a negative correlation with the duration of hemodialysis, intima-media thickness, intact parathyroid hormone, and low-density lipoprotein cholesterol by multiple regression analysis. These findings suggest that the decrease of bone mineral density in hemodialysis patients is correlated with secondary hyperparathyroidism and hyperlipidemia, which are factors known to promote atherosclerosis, and thus bone density changes might be related to the progression of atherosclerosis, or vice versa.