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Objective:To investigate the significance of filtration fraction (FF) and renal artery stenting in the treatment of atherosclerotic renal artery stenosis.Methods:In the study,42 cases of renal artery stenosis were treated with 52 renal artery stent implantation.Percutaneous transluminal renal angioplasty and stent (PTRAS) of the patients' health side kidney,ipsilateral kidney (renal) glomerular filtration rate (GFR),renal effective renal plasma flow effective renal plasma flow (ERPF),kidney filtration fraction changes of preoperative and postoperative serum creatinine (SCR) and the changes in the patients with blood pressure (SBP) and the changes after taking antihypertensive drugs were observed and analyzed.Results:The 52 cases of renal artery stent implantation were all successful.Preoperative ipsilateral GFR was significantly lower than that of normal side (t =-3.989,P =0.000);preoperative ipsilateral ERPF was significantly lower than the contralateral side (t =-4.926,P =0.000).On both sides,the overall FF values were equal (t =1.273,P =O.207).Postoperative ipsilateral renal GFR was increased,but there was no statistical difference (t =-1.411,P =0.164).Postoperative ipsilateral renal ERPF was increased significantly (t =-4.954,P =0.000),and FF lower (closer to the normal value (t =3.274,P =0.002).Postoperative side GFR was significantly reduced (t =2.569,P =0.000),the contralateral ERPF was significantly reduced (t =3.889,P =0.001),and FF had no significant change (t =-0.758,P =0.454).Postoperative side GFR was lower than that of the contralateral (t =-3.283,P =0.002) and postoperative side ERPF was still lower than that of the contralateral (t =-3.351,P =0.001),but on both sides,the FF values were equal (t =-0.361,P =0.719).Preoperative FF was relatively normal in the patients with kidney,and the postoperative FF value change was small (t =O.799,P =O.430);preoperative FF was significantly higher in the patients with kidney,and the postoperative FF value was lower than the preoperative (normal value,t =5.299,P =0.000).Postoperative overall serum creatinine was significantly decreased (t =2.505,P =0.016);but for the patients with unilateral renal artery stenosis,the changes in serum creatinine had no statistical difference (t =1.228,P =0.299);and for the patients with bilateral renal artery stenosis and serum creatinine compared with the preoperative,the changes were decreased significantly (t =2.518,P =0.030);postoperative blood pressure (SBP) was significantly decreased compared with that before operation (t =8.945,P =0.000);antihypertensive drugs taken were decreased significantly compared with the preoperative (t =5.280,P =0.000).Conclusion:For the patients with renal artery stenosis,FF is a useful index to understand the pathophysiological process of renal ischemia.Whether preoperative FF is significantly increased or FF is relatively normal,should be regarded as the indications of renal artery stent implantation.
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Purpose To explore the influence of duration of scan acquisition on perfusion parameters in whole renal perfusion with Revolution CT.Materials and Methods Fortytwo patients without pathologic changes in bilateral kidneys were divided into group A (with short perfusion time) and group B (with long perfusion time) according to the duration time of the perfusion scan.The Revolution CT axial scan mode was used for perfusion scan,and the width of detector was 16 cm.The perfusion CT series were performed in 50 seconds,each comprising 25 volumes with identical parameters (80 kVp,200 mA) in group A.The perfusion CT series were performed in 594 seconds,each comprising 23 volumes with identical parameters (120 kVp,55 mA) in group B.The source datasets were post-processed with CT Perfusion 4D software,and the perfusion parameter maps were obtained when right renal abdominal aorta was taken as entry artery.Perfusion parameters of bilateral kidneys were compared within and between group A and group B,respectively.CT dosage index of volume (CTDIvol) and dose length product (DLP) were recorded.The effective dose (ED) was calculated and compared.Results There were no statistical difference in all parameters between bilateral kidneys within each group (P＞0.05).However,blood volume,time to peak,and permeability surface in the cortex and medulla of bilateral kidneys all showed differences between the above two groups (P＜0.05).The mean transit time in the medulla between the two groups was different (P＜0.05),but neither the blood flow in the medulla and cortex nor the mean transit time of the cortex had difference between the two groups (P＞0.05).The effective radiation doses were (23.10± 4.39)mSv in group A and (23.19±0.00) mSv in group B,respectively (without statistic difference:P＞0.05).Conclusion CT perfusion parameters with different duration time show differences in whole renal perfusion;therefore,scanning time needs to be set according to the clinical application.
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Objective To determine the accuracy of renal blood flow assessment by transesophageal echocardiography (TEE) during carbon dioxide (CO2) pneumoperitoneum.Methods The left renal arterial diameter (RAD) and the Doppler velocity time integral (VTI) were measured by TEE before peumoperitoneum (T0, baseline), at 1, 5, 10, 15, 20 and 30 min of pneumoperitoneum and 1 and 5 min after deflation in 35 patients undergoing elective laparoscopic cholecystectomy. The left renal blood flow (LRBF) and the left renal blood perfusion resistance (LRPR) were calculated according to the following formulae: LRBF = 1/4π x RAD2 x VTI x HR, LRPR = MAP/LRBF.Three months later, the TEE images of 10 cases were randomly selected and reviewed by the same and another research team member to check the repeatability and consistency of the LRBF determination during operation, respectively. The quality of the TEE images was evaluated by another specialist.Results Before pneumoperitoneum, 94% of the TEE images were rated as satisfactory. There was no significant difference between the qualities of the TEE images obtained before and during pneumoperitoneum. The variabilities between the RADs measured by TEE during and 3 months after operation were 9.28% by the same team member and 8.71% by another team member. The variabilities between the VTIs measured by TEE during and 3 months after operation were 5.61% by the same team member and 6.25% by another team member. The linear regression analysis of the LRBF showed that the slope and the intercept were 1.05 and 31.4 ml/min respectively by the same member and 0.92 and 47.3 ml/min respectively by another member. The LRBF was decreased during pneumoperitoneum and the LRPR was increased.Conclusion TEE can be used to accurately monitor the changes in renal blood flow during CO2 pneumoperitoneum.