High prevalence of leukoaraiosis in cerebral magnetic resonance images of patients on peritoneal dialysis.

BACKGROUND: Leukoaraiosis is a term used to define the abnormal appearance of subcortical white matter of the brain by means of neuroimaging and is regarded as an intermediate surrogate of stroke. The goal of this study is to identify the prevalence of leukoaraiosis and analyze predictors of risk of leukoaraiosis. STUDY DESIGN: Cross-sectional study. SETTING & PARTICIPANTS: 57 peritoneal dialysis (PD) patients without diabetes treated in 3 academic medical-associated dialysis units who did not have a history of cerebrovascular disease or neurological symptoms compared with a convenience sample of 57 age- and sex-matched hypertensive control subjects with normal renal function. PREDICTOR: End-stage renal disease treated by PD compared with hypertension, adjusted for clinical and laboratory characteristics. OUTCOME & MEASUREMENT: Hyperintense areas on magnetic resonance imaging T2 high-signal intensity scoring system. RESULTS: The prevalence of leukoaraiosis was significantly greater in patients on PD therapy than controls (68.4% versus 17.5%; P < 0.001). High T2 signal intensity score in patients on PD therapy compared with controls was significantly higher in the anterior circulation of the brain, relatively sparing the posterior fossa. End-stage renal disease, age, and poor control of blood pressure were significant independent predictors of leukoaraiosis. LIMITATIONS: There is the possibility that biases regarding the selection of enrolled patients had an influence on a study result. CONCLUSIONS: Cerebral magnetic resonance imaging of PD patients without evidence of cerebrovascular disease showed a high prevalence of leukoaraiosis in the anterior circulation of the brain. Old age, poorly controlled hypertension, and the PD procedure itself and/or end-stage renal disease seem to be associated with the presence of leukoaraiosis.

Can magnetic resonance angiogram be a reliable alternative for donor evaluation for laparoscopic nephrectomy?

BACKGROUND: While hand-assisted laparoscopic donor nephrectomy (HLDN) is less invasive, which can encourage kidney donation, it requires more exact information about the renal vascular anatomy because of its limited visual field during nephrectomy. MRA is also an attractive choice because of its minimal invasiveness; further, it is an outpatient-based procedure, it uses non-nephrotoxic contrast material and it has no radiation. The aim of our study was to evaluate the effectiveness of gadolinium enhanced three-dimensional MRA (GdE-3D MRA) in a group of potential live donors who were candidates for HLDN. METHODS: From September 2002 to December 2004, 40 potential live renal donors were evaluated prospectively with GdE-3D MRA, and this imaging modality was performed before the gold standard, the intra-arterial digital subtraction angiogram (IA-DSA), was carried out. All the images were reviewed in a blinded manner by the attending vascular radiologist. The MRA findings were compared with the DSA findings and the surgical findings as the reference methods. We evaluated the accuracy of MRA for imaging the renal architectures, and especially for imaging the renal accessory arteries and the early branching arteries that are important determinants for selection of the donor kidney. RESULTS: Both the MRA and DSA images showed consistent findings with the surgical findings in 92.5% of the 40 donors. There were no discrepant cases in depicting the main renal artery. MRA showed 100% specificity for imaging both the renal accessory arteries and the early branching arteries, when compared with the surgical findings. The kappa values for the MRA and DSA for the accessory arteries were all 0.66 compared with the intraoperative findings. MRA also depicted one huge renal cyst in one donor and many small renal cysts in the other donors that could not be imaged by DSA. There were no adverse events during the MRA procedure. None of the findings missed by MRA resulted in deleterious consequences at laparoscopic nephrectomy for the donor and graft. CONCLUSIONS: Our limited experience with GdE-3D MRA for imaging the renal structures in kidney donor evaluation for HLDN has been quite satisfactory.

Coronary-artery calcium scores using electron beam CT in patients with chronic renal failure.

We evaluated the risk of coronary-artery disease in patients with chronic renal failure (CRF) by measuring the coronary-artery calcium scores with electron beam CT (EBCT). A total of 81 CRF patients were divided into three groups; pre-dialysis (group I, n = 35), hemodialysis (group II, n = 31) and peritoneal dialysis (group III, n = 15). The several serum biochemical markers and calcium score levels by EBCT were determined. The Ca x P products were significantly higher in groups II (p < 0.05) and III (p < 0.01) than in group I. The serum calcium levels were significantly higher in group III than in both group I (p < 0.01) and II (p < 0.05). The serum calcium level in 15 patients with a calcium score > 400 was significantly higher than the 66 patients with a score < or =400 (p < 0.01). The calcium score was significantly higher in the 15 patients with cardiovascular complications than in the 66 patients without cardiovascular complications (628.9+/-904.8 vs. 150.4+/-350.9, p < 0.01). EBCT seemed to be a good diagnostic tool for evaluating the risk of coronary-artery disease ''noninvasively'' in CRF patients who are at increased risk of cardiovascular morbidity and mortality.

Usefulness of the dialysis adequacy and transport test in peritoneal dialysis.

Instead of the peritoneal equilibration test (PET), the dialysis adequacy and transport test (DATT) is an easy and convenient method to classify peritoneal transport type. However, the peritoneal transport characteristics obtained from the DATT and the PET are not same in some cases. In the present study, we investigated the ability of the DATT to identify peritoneal transport characteristics in a clinical setting, and we analyzed the characteristics of patients with a discrepancy between the DATT and the PET. We studied 106 patients on continuous ambulatory peritoneal dialysis (CAPD) who underwent 198 simultaneous DATTs and PETs. The 24-hour dialysate-to-plasma ratio of creatinine (D / P(Cr)) from each DATT was compared with the adjusted 4-hour D/P(Cr) from the corresponding PET. Based on the degree of the mean discrepancy between the 24-hour D / P(Cr) and the adjusted 4-hour D / P(Cr) the patients were divided into three groups: Group A patents had 24-hour D / P(Cr) values that were lower than the adjusted 4-hour D / P(Cr) values (n=13). Group B patients had 24-hour D / P(Cr) values that were equivalent to the adjusted 4-hour D / P(Cr) values (n=156). Group C patients had 24-hour D / P(Cr) values that were higher than the adjusted 4-hour D / P(Cr) values (n=29). The comparative analysis among the three groups was adjustedforperitoneal transport characteristics, dialysis adequacy indices, nutrition status, and daily dialysis prescription. The 24-hour D / P(Cr) from the DATT correlated significantly with the 4-hour D / P(Cr) (gamma = 0.759, p < 0.0001). In 156 cases (78.8%), the D / P(Cr) values from the DATT and the PET showed reasonable agreement; but, in 42 cases (21.2%), the values were discordant. In 94 cases (47.5%), the peritoneal transport groups as classified by the DATT and the PET were discordant. The mean difference in D / P(Cr) between the DATT and the PET was 0.07 +/- 0.08, and the DATT differed significantly from the PET in categorizing the low and low-average transport groups (p < 0.05). A significant difference was seen between the three groups in daily exchange volume (group A: 7384.6 +/- 1502.2 mL; group B: 7537.3 +/- 1087.7 mL; group C: 6675.9 +/- 1414.6 mL; p < 0.05) and in the frequency of daily exchanges (group A: 3.7 +/- 0.8 exchanges; group B: 3.8 +/- 0.4 exchanges; group C: 3.4 +/- 0.7 exchanges; p < 0.05). We confirmed that the DATT is an easy and convenient method of identifying peritoneal membrane transport instead of the PET, and that the DATT can be generalized to patients receiving various dialysis prescriptions and to patients receiving four daily exchanges. However, the DATT may be less accurate for CAPD patients with low or low-average transport, and the higher value of D / P(Cr) derived from the DATT, as compared with the PET, is attributable to longer dwell times and a lower dwell volume.