Stereological and Morphometric Analysis of MRI Chiari Malformation Type-1.

OBJECTIVE: In this study, we aimed to investigate the underlying ethiological factors in chiari malformation (CM) type-I (CMI) via performing volumetric and morphometric length-angle measurements. METHODS: A total of 66 individuals [33 patients (20-65 years) with CMI and 33 control subjects] were included in this study. In sagittal MR images, tonsillar herniation length and concurrent anomalies were evaluated. Supratentorial, infratentorial, and total intracranial volumes were measured using Cavalieri method. Various cranial distances and angles were used to evaluate the platybasia and posterior cranial fossa (PCF) development. RESULTS: Tonsillar herniation length was measured 9.09±3.39 mm below foramen magnum in CM group. Tonsillar herniation/concurrent syringomyelia, concavity/defect of clivus, herniation of bulbus and fourth ventricle, basilar invagination and craniovertebral junction abnormality rates were 30.3, 27, 18, 2, 3, and 3 percent, respectively. Absence of cisterna magna was encountered in 87.9% of the patients. Total, IT and ST volumes and distance between Chamberlain line and tip of dens axis, Klaus index, clivus length, distance between internal occipital protuberance and opisthion were significantly decreased in patient group. Also in patient group, it was found that Welcher basal angle/Boogard angle increased and tentorial slope angle decreased. CONCLUSION: Mean cranial volume and length-angle measurement values significantly decreased and there was a congenital abnormality association in nearly 81.5 percent of the CM cases. As a result, it was concluded that CM ethiology can be attributed to multifactorial causes. Moreover, congenital defects can also give rise to this condition.

The clinical utility of vascular mapping with Doppler ultrasound prior to arteriovenous fistula construction for hemodialysis access.

PURPOSE: To compare the outcomes of vascular access (VA) procedures performed using physical examination (PE) alone to PE and ultrasound vein mapping for assessment of patients needing hemodialysis access. METHODS: Comparative analysis of data obtained by retrospective review of records of 63 patients who underwent PE and vascular mapping (VM) using colored Doppler ultrasonography (CDUS) and 76 patients assessed by physical examination alone to schedule vascular access surgery. The parameters assessed to study the impact of these two different pre-operative assessment approaches included selection of surgical site, procedure, construction of arteriovenous fistulas (AVF) and grafts (AVG), negative surgical exploration rates and surgical outcomes (maturation and patency rates). RESULTS: The rate of successfully constructed AVF increased significantly from 75% to 97% (P=.001) with pre-operative ultrasonographic vascular mapping. In 22 patients (34.9%) the access planned with physical examination was modified based on CDUS examination. In 12 patients, the surgical site for AVF creation and type of surgical procedure were modified based on the CDUS results. Permanent access placement rates were significantly higher in patients assessed with CDUS (P=.001). All patients who underwent vascular mapping had successful VA construction while the PE group had a 18.4% negative surgical exploration rate. When fistulas were assessed at six months, the patency rate was 80.7% for the physical examination (PE) group and 93.4% for the vascular mapping (VM) group. CONCLUSIONS: Pre-operative vascular mapping using CDUS significantly increases the success of AVF construction and patency.

Impact of diabetic and pre-diabetic state on development of contrast-induced nephropathy in patients with chronic kidney disease.

BACKGROUND: The aim of the present study was to assess the influence of diabetic and pre-diabetic state on the development of contrast-induced nephropathy (CIN) in chronic kidney disease patients undergoing coronary angiography. METHODS: A total of 421 patients with Cockcroft clearance between 15 and 60 ml/min were divided into three groups [diabetes mellitus (DM), n = 137; pre-diabetes (pre-DM), n = 140; and normal fasting glucose (NFG), n = 144]. CIN was defined as an increase of > or =25% in creatinine over baseline within 48 h of angiography, DM as glucose > or =126 mg/dl, pre-DM as glucose between 100 and 125 mg/dl and NFG as glucose <100 mg/dl. RESULTS: CIN occurred in 20% of the DM [relative risk (RR) 3.6, P = 0.001], 11.4% of the pre-DM (RR 2.1, P = 0.314) and 5.5% of the NFG group. The decrease of glomerular filtration rate (GFR) was higher in DM and pre-DM (P = 0.001 and P = 0.002, respectively). GFR < or =30 ml/min (RR 19.22), multivessel involvement (RR 7.59), hyperuricaemia (RR 3.95), use of angiotensin-converting enzyme inhibitors or angiotensin II receptor blocker (RR 2.70) and DM (RR 2.34) were predictors of CIN. Length of hospital stay was 2.45 +/- 1.45 day in DM, 2.27 +/- 0.68 day in pre-DM and 1.97 +/- 0.45 day in NFG (P < 0.001, DM vs NFG and P = 0.032, pre-DM vs NFG). The rate of major adverse cardiac events was 8.7% in DM, 5% in pre-DM and 2.1% in NFG (P = 0.042, DM vs NFG). Haemodialysis was required in 3.6% of DM and 0.7% in pre-DM (P = 0.036, DM vs NFG), and the total number of haemodialysis sessions during 3 months was higher in DM and pre-DM (P < 0.001). Serum glucose > or =124 mg/dl was the best cut-off point for prediction of CIN. CONCLUSION: Our data support that patients with DM are at a higher risk of developing CIN, but patients with pre-DM are not at as high a risk for developing CIN as diabetes patients.

Angiotensin-converting enzyme inhibitors as a risk factor for contrast-induced nephropathy.

BACKGROUND/AIMS: The aim of the present study was to assess the influence of chronic angiotensin-converting enzyme (ACE) inhibitor administration on the development of contrast-induced nephropathy (CIN) in patients undergoing coronary angiography. METHODS: A total of 230 patients with renal insufficiency and age > or =65 years were divided into two groups according to prior use of ACE inhibitors (ACE inhibitor group, n = 109; control group, n = 121). CIN was defined as an increase of > or =25% in creatinine over the baseline value within 48 h of angiography. RESULTS: CIN occurred in 17 patients (15.6%) in the ACE inhibitor group and 7 patients (5.8%) in the control group (p = 0.015). Serum creatinine level increased from 1.34 +/- 0.20 to 1.53 +/- 0.27 mg/dl in the ACE inhibitor group and from 1.33 +/- 0.18 to 1.45 +/- 0.19 mg/dl in the control group (p < 0.001). Chronic ACE inhibitor administration was a risk indicator of CIN [odds ratio 3.37; 95% confidence interval 1.14-9.94; p = 0.028]. Multi-vessel coronary involvement (p = 0.001), hypoalbuminemia (p = 0.005), diabetes mellitus (p = 0.006), GFR < or =40 ml/min (p = 0.010), and congestive heart failure (p = 0.024) were other risk indicators of CIN. CONCLUSION: Chronic ACE inhibitor administration is a risk for developing CIN in elderly patients with renal insufficiency.

Metabolic syndrome as a risk factor for contrast-induced nephropathy in non-diabetic elderly patients with renal impairment.

BACKGROUND/AIMS: Metabolic syndrome (MS) as a risk factor for contrast-induced nephropathy (CIN) has not been studied. The aim of the present study was to assess the influence of MS on the development of CIN in patients undergoing coronary angiography. METHODS: This was a prospective cohort study. A total of 219 non-diabetic patients with reduced kidney function and age >or=60 years were divided into two groups (MS, n = 107 and non-MS, n = 112). CIN was defined as an increase of >or=25% in creatinine over the baseline value within 48 h of angiography. RESULTS: CIN occurred in 14% of the MS group and 3.6% of the non-MS group (p = 0.006). Serum creatinine increased from 1.06 +/- 0.17 to 1.12 +/- 0.27 mg/dl in the MS group and from 1.03 +/- 0.17 to 1.09 +/- 0.23 mg/dl in the non-MS group (p < 0.001). MS was a risk indicator of CIN [odds ratio (OR) 4.26; 95% confidence interval (95% CI) 1.19-15.25; p = 0.026). Impaired fasting glucose (OR 4.72; 95% CI 1.53-14.56; p = 0.007), high triglyceride (OR 4.06; 95% CI 1.22-13.44; p = 0.022), and multivessel involvement (OR 3.14; 95% CI 1.07-9.82; p = 0.038) in the MS group were predictors of CIN. CONCLUSION: Our data support the hypothesis that patients with MS are at risk of developing CIN.

Hyperuricemia as a risk factor for contrast-induced nephropathy in patients with chronic kidney disease.

OBJECTIVES: Hyperuricemia as a risk factor for contrast-induced nephropathy (CIN) has not been studied. BACKGROUND: The aim of the present study was to assess the influence of hyperuricemia on the development of CIN in patients undergoing coronary angiography. METHODS: This was a prospective cohort study. A total of 266 patients with a mean age of 58.33 +/- 7.85 years and serum creatinine > or = 1.2 mg/dl were divided into two groups (hyperuricemic, n = 126, and normouricemic, n = 140). CIN was defined as an increase of > or = 25% in creatinine over baseline within 48 hr of angiography, and hyperuricemia as serum uric acid > or = 7 mg/dl in males and > or = 6.5 mg/dl in females. RESULTS: CIN occurred in 15.1% of the hyperuricemic group and 2.9% of the normouricemic group (P < 0.001). Serum creatinine increased from 1.45 +/- 0.20 to 1.67 +/- 0.45 mg/dl in the hyperuricemic group and from 1.42 +/- 0.16 to 1.56 +/- 0.23 mg/dl in the normouricemic group (P < 0.001). Hyperuricemia [odds ratio (OR) 4.71; 95% confidence interval (95% CI) 1.29-17.21; P = 0.019] and a high incidence of multi-vessel coronary involvement (OR 3.59; 95% CI 1.12-11.48; P = 0.032) in the hyperuricemic group were predictors of CIN. Hypoalbuminemia (P = 0.001) and age > or = 70 years (P = 0.023) were other risk indicators of CIN. Length of hospital stay (P < 0.001) and CIN requiring renal replacement therapy (P = 0.017) were significantly higher in hyperuricemic group. Serum uric acid level > or = 7 mg/dl in males and > or = 5.9 mg/dl in females were found to be the best cut-off value for prediction of CIN. CONCLUSION: Our data support the hypothesis that patients with hyperuricemia are at risk of developing CIN.