Indocyanine green plasma clearance rate and 99mTc-galactosyl human serum albumin single-photon emission computed tomography evaluated preoperative remnant liver

BACKGROUND Preoperative evaluation of future remnant liver reserves is important for safe hepatectomy.If the remnant is small,preoperative portal vein embolization(PVE)is useful.Liver volume analysis has been the primary method of preoperative evaluation,although functional examination may be more accurate.We have used the functional evaluation liver using the indocyanine green plasma clearance rate(KICG)and 99mTc-galactosyl human serum albumin single-photon emission computed tomography(99mTc-GSA SPECT)for safe hepatectomy.AIM To analyze the safety of our institution’s system for evaluating the remnant liver reserve.METHODS We retrospectively reviewed the records of 23 patients who underwent preoperative PVE.Two types of remnant liver KICG were defined as follows:Anatomical volume remnant KICG(a-rem-KICG),determined as the remnant liver anatomical volume rate×KICG;and functional volume remnant KICG(frem-KICG),determined as the remnant liver functional volume rate based on 99mTc-GSA SPECT×KICG.If either of the remnant liver KICGs were>0.05,a hepatectomy was performed.Perioperative factors were analyzed.We defined the marginal group as patients with a-rem-KICG of<0.05 and a f-rem-KICG of>0.05 and compared the postoperative outcomes between the marginal and not marginal(both a-rem-KICG and f-rem-KICG>0.05)groups.RESULTS All 23 patients underwent planned hepatectomies.Right hepatectomy,right trisectionectomy and left trisectionectomy were in 16,6 and 1 cases,respectively.The mean of blood loss and operative time were 576 mL and 474 min,respectively.The increased amount of frem-KICG was significantly larger than that of a-rem-KICG after PVE(0.034 vs 0.012,P=0.0273).The not marginal and marginal groups had 17(73.9%)and 6(26.1%)patients,respectively.The complications of Clavian-Dindo classification grade II or higher and post-hepatectomy liver failure were observed in six(26.1%)and one(grade A,4.3%)patient,respectively.The 90-d mortality was zero.The marginal group had no significant difference in postoperative outcomes(prothrombin time/international normalised ratio,total bilirubin,complication,post-hepatectomy liver failure,hospital stay,90-d,and mortality)compared with the not-marginal group.CONCLUSION Functional evaluation of the remnant liver enabled safe hepatectomy and may extend the indication for hepatectomy after PVE treatment.

Study on the accuracy of glomerular filtration rate formulas by double plasma method as "gold standard"

Objective: To evaluate the accuracy of glomerular filtration rate formula by comparising the CKD-EPI 2009 formula and the modified Modified MDRD formula with the 99mTc-DTPA double-phase plasma method as "gold standard" respectively. Methods: Totally 166 patients diognosed as chronic kidney disease (CKD) were enrolled. The 99mTc-DTPA double-plasma method (rGFR) was used as the "gold standard". The CKD-EPI 2009 formula and the modified MDRD formula were used to calculate eGFR. Statistical software was used to analyze the correlation between the calculated values of the two formulas and the gold standard value and the bias. Then we evaluated the accuracy of the two GFR formulas. Results: Among the CKD stage 1 patients, the bias of the CKD-EPI 2009 formula was smaller than that of the Modified MDRD formula (13.9911.45;20.1815.90);both formulas were weakly correlated with the gold standard (correlation coefficients were 0.216, 0.229, P<0.01, respectively);The probability that the bias of the calculated value of the CKD-EPI 2009 formula less than 15%, 30%, and 50% of the gold standard value is smaller. Among the CKD stage 2 patients, the bias of the CKD-EPI 2009 formula was smaller than that of the Modified MDRD formula (12.748.45;15.6811.01);both formulas were moderately correlated with the gold standard (correlation coefficients were 0.568, 0.581, P<0.01, respectively);The probability that the bias of the calculated value of the CKD-EPI 2009 formula less than 15%, 30%, and 50% of the gold standard value is smaller. Among the CKD stage 3 patients, the bias of the CKD-EPI 2009 formula was smaller than that of the Modified MDRD formula (12.6410.27;12.8810.97), and both formulas were strongly correlated with the gold standard (correlation coefficients were 0.664, 0.670, P<0.01, respectively);The probability that the bias of the calculated value of the Modified MDRD formula less than 15%, 30%, and 50% of the gold standard value is smaller. Among the CKD stage 4 to 5 patients, the bias of the CKD-EPI 2009 formula was smaller than that of the Modified MDRD formula (5.585.36;5.945.20);The CKD-EPI 2009 formula and the Modified MDRD formula were strongly correlated with the gold standard (correlation coefficient r was 0.808. 0.802, P<0.01, respectively);The probability of the bias of the calculated value of the CKD-EPI 2009 formula less than 15%, 30%, and 50% of the gold standard value is smaller. In patients with decreased renal function with GFR <60 ml/min, the sensitivity and positive predictive value of the CKD-EPI 2009 formula for the diagnosis of "decreased renal function"were higher, and the specificity was comparable. Conclusion: 1. When the renal function is only slightly decreased, the accuracy of the two formulas is not good. In this condition, the CKD-EPI 2009 formula is more accurate and recommended. 2. It is necessary to further improve the current formulas especialy when it comes to value the slightly declined renal function;3. When we try to identify the stage of CKD patients, only based on eGFR may cause misclassification, it is recommended to combine the cause-GFR-albuminuria staging to assess the stage of CKD;4. The current formulas have limitations.in the case that requires a highly accurate assessment of GFR, the 99mTc-DTPA dual plasma method is recommended.

The Choice Between Three Simple Methods for Glomerular Filtration Rate Assessment in Different Stages of Chronic Parenchymal Renal Diseases

Glomerular filtration rate （GFR） can be measured （mGFR） after intravenous application of indicators that are eliminated by kidneys or estimated （eGFR） using mathematic equations. We have compared eGFR obtained by the chronic kidney diseases epidemiology collaboration （CKD-EPI） and the Modification of diet in renal disease （MDRD） Study equations with GFR measured by technetium-99m diethylene triamine penta-acetic acid （99m^Te-DTPA） renal clearance in different stages of renal diseases in order that obtained results may contribute to more adequate choice of methods for the GFR assessment in relation to the type and stage of kidney disease. The study included a total of 189 participants with diabetes mellitus （DM）, glomerulonephritis （GN）, Balkan endemic nephropathy （BEN） and healthy subjects. 99m^Tc-DTPA clearance （ml/min/1.73 m^2） was calculated from the regression equation based on high correlation between distribution volume of radiopharmaceutical and clearance values obtained by multiple blood samples. For blood sample taken at 3 h and 4 h, clearance was calculated according to the equations： y = -0.0128x^2 ＋ 3.077x - 30.3, and y = -0.00628x^2 ＋ 2.066x - 19.3, where y is clearance, and x is distribution volume. MDRD-GFR （ml/min/l.73 m2） was calculated from equation： 186 × Scr^-1154 × age^-0.203 × 0.742 if female. CKD-EPI-GFR was calculated from equation： 141 × min（Scr/K, 1）^ α ×max（Scr/K, 1）^-1 209 × 0.993age × 1.018 if female, where Scr is serum creatinine, n is 0.7 for females and 0.9 for males, c~ is -0.329 for females and -0.411 for males, min indicates the minimum of Scr/K or 1, and max indicates the maximum of Scr/κ or 1. Irrespective of renal disease, both equations underestimated radionuclide clearance at mGFR 〉 90 ml/min/1.73 m^2 （91.7 ± 18.8 and 88.2 ± 22.0 vs. 121± 19.6, p〈0.0001） and at mGFR 60-89 ml/min/1.73 m^2 （67.1 ±19.9 and 65.8 ± 19.9 vs. 75.8 ± 9.2, p 〈 0.05 and p 〈 0.005）. They were also significantly lower than mGFR in DM patients with GFR 〉_ 90 ml/min/1.73 m^2. In patients with GFR 〉 60 ml/min/1.73 m^2, the median bias of CKD-EPI equation was lower and accuracy （percent of eGFR within 30% of mGFR, P30） was higher than that of MDRD equation. Nevertheless, in DM patients with GFR _〉 90 ml/min the accuracy of the former equation is significantly better than that of MDRD formula. Patients GFR 〈 60 ml/min had the similar bias and accuracy both eGFR equations. As CKD-EPI equation has lesser bias and improved accuracy than MDRD equation in patients with GFR 〉 60 ml/min, we suggest its use for prediction of GFR at higher renal function levels. However, underestimation of renal function by CKD-EPI equation seems not to be quite appropriate in diabetic patients with expected GFR above 90 ml/min because it may miss the patients with glomerular hyperfiltration. Thus, priority may be given to 99m^Tc-DTPA clearance method in the earlier stages of kidney diseases in type 1 diabetes mellitus. At last, in patients with expected GFR 〈 60 ml/min, it is better to monitor disease progression by estimating equations than by 99m^Tc-DTPA renal clearance, due to their simpler implementation.