RESUMO
Renal transplant vein stenosis is a rare cause of allograft dysfunction. Percutaneous stenting appears to be safe and effective treatment for this condition. A 56-year-old Caucasian female with end stage renal disease received a deceased donor renal transplant. After transplant, her serum creatinine improved to a nadir of 1.2 mg/dL. During the third posttransplant month, her serum creatinine increased to 2.2 mg/dL. Renal transplant biopsy showed BK nephropathy. Mycophenolate was discontinued. Over the next 2 months, her serum creatinine crept up to 6.2 mg/dL. BK viremia improved from 36464 copies/mL to 15398 copies/mL. A renal transplant ultrasound showed lower pole arteriovenous fistula and abnormal waveforms in the renal vein. Carbon dioxide (CO2) angiography demonstrated severe stenosis of the transplant renal vein. Successful coil occlusion of fistula was performed along with angioplasty and deployment of stent in the renal transplant vein. Serum creatinine improved to 1.5 mg/dL after.
RESUMO
BACKGROUND: Estimating glomerular filtration rate (GFR) in severely ill inpatients is clinically important for therapeutic interventions and prognosis, but notoriously difficult to do accurately. The Modification of Diet in Renal Disease (MDRD) equation and Cockcroft-Gault (CG) formula are widely used to estimate renal function in sick hospitalized patients; however, neither method has been validated in this setting. METHODS: Iodine 125-iothalamate clearances (iGFR) performed in 107 sick inpatients with renal dysfunction were compared with estimated GFRs (eGFRs) from the 6- and 4-variable MDRD (MDRD eGFR) and CG (CG eGFR) equations. RESULTS: Mean serum creatinine (SCr) level was 3.5 +/- 2.0 mg/dL (309 +/- 177 micromol/L), and mean iGFR was 17.1 +/- 17.9 mL/min/1.73 m2 (0.29 +/- 0.30 mL/s/1.73 m2). Six-variable MDRD eGFR was 22.5 +/- 17.4 mL/min/1.73 m2 (0.38 +/- 0.29 mL/s/1.73 m2), 4-variable MDRD eGFR was 23.9 +/- 16.3 mL/min/1.73 m2 (0.40 +/- 0.27 mL/s/1.73 m2), and CG eGFR was 26.0 +/- 17.1 mL/min/1.73 m2 (0.43 +/- 0.29 mL/s/1.73 m2). Blood urea nitrogen (BUN)/SCr ratios greater than 20 were seen in 58% of patients. Overall, the CG and MDRD equations overestimated iGFR, with poor agreement. Overestimation of at least 25% of measured iGFR was seen in 63%, 67%, and 70% of all inpatients when using the 6-variable MDRD, 4-variable MDRD, and CG equations, respectively. Accuracy of eGFR within 50% of measured iGFR was 55% for the 6-variable MDRD equation, 49% for the 4-variable MDRD equation, and 40% for the CG formula. The performance of both methods deteriorated further in patients with a BUN/SCr ratio greater than 20. CONCLUSION: Estimation equations are performed poorly compared with iGFR and are not reliable measures of actual level of function in sick hospitalized patients, especially those with a high BUN/SCr ratio. Although use of the 6-variable MDRD equation provides a better estimation of GFR, it still is unsuitable for clinical application in this population.
