CT volumetry is superior to nuclear renography for prediction of residual kidney function in living donors.

Living kidney donor evaluation commonly includes nuclear renography to assess split kidney function and computed tomography (CT) scan to evaluate anatomy. To streamline donor workup and minimize exposure to radioisotopes, we sought to assess the feasibility of using proportional kidney volume from CT volumetry in lieu of nuclear renography. We examined the correlation between techniques and assessed their ability to predict residual postoperative kidney function following live donor nephrectomy. In a cohort of 224 live kidney donors, we compared proportional kidney volume derived by CT volumetry with split kidney function derived from nuclear renography and found only modest correlation (left kidney R(2) =26.2%, right kidney R(2) =26.7%). In a subset of 88 live kidney donors with serum creatinine measured 6 months postoperatively, we compared observed estimated glomerular filtration rate (eGFR) at 6 months with predicted eGFR from preoperative imaging. Compared to nuclear renography, CT volumetry more closely approximated actual observed postoperative eGFR for Chronic Kidney Disease Epidemiology Collaboration (J-test: P=.02, Cox-Pesaran test: P=.01) and Mayo formulas (J-test: P=.004, Cox-Pesaran test: P<.001). These observations support the use of CT volumetry for estimation of split kidney function in healthy individuals with normal kidney function and morphology.

Biliary complications in pediatric liver transplantation: Incidence and management over a decade.

This study analyzed how features of a liver graft and the technique of biliary reconstruction interact to affect biliary complications in pediatric liver transplantation. A retrospective analysis was performed of data collected from 2001 to 2011 in a single high-volume North American pediatric transplant center. The study cohort comprised 173 pediatric recipients, 75 living donor (LD) and 98 deceased donor (DD) recipients. The median follow-up was 70 months. Twenty-nine (16.7%) patients suffered a biliary complication. The majority of leaks (9/12, 75.0%) and the majority of strictures (18/22, 81.8%) were anastomotic. There was no difference in the rate of biliary complications associated with DD (18.4%) and LD (14.7%) grafts (P = 0.55). Roux-en-Y (RY) reconstruction was associated with a significantly lower rate of biliary complications compared to duct-to-duct reconstruction (13.3% versus 28.2%, respectively; P = 0.048). RY anastomosis was the only significant factor protecting from biliary complications in our population (hazard ratio, 0.30; 95% confidence interval, 0.1-0.85). The leaks were managed primarily by relaparotomy (10/12, 83.3%), and the majority of strictures were managed by percutaneous biliary intervention (14/22, 63.6%). Patients suffering biliary complications had inferior graft survival (P = 0.04) at 1, 5, and 10 years compared to patients without biliary complications. Our analysis demonstrates a lower incidence of biliary complications with RY biliary reconstruction, and patients with biliary complications have decreased graft survival.

Generation of subcutaneous and intrahepatic human hepatocellular carcinoma xenografts in immunodeficient mice.

In vivo experimental models of hepatocellular carcinoma (HCC) that recapitulate the human disease provide a valuable platform for research into disease pathophysiology and for the preclinical evaluation of novel therapies. We present a variety of methods to generate subcutaneous or orthotopic human HCC xenografts in immunodeficient mice that could be utilized in a variety of research applications. With a focus on the use of primary tumor tissue from patients undergoing surgical resection as a starting point, we describe the preparation of cell suspensions or tumor fragments for xenografting. We describe specific techniques to xenograft these tissues i) subcutaneously; or ii) intrahepatically, either by direct implantation of tumor cells or fragments into the liver, or indirectly by injection of cells into the mouse spleen. We also describe the use of partial resection of the native mouse liver at the time of xenografting as a strategy to induce a state of active liver regeneration in the recipient mouse that may facilitate the intrahepatic engraftment of primary human tumor cells. The expected results of these techniques are illustrated. The protocols described have been validated using primary human HCC samples and xenografts, which typically perform less robustly than the well-established human HCC cell lines that are widely used and frequently cited in the literature. In comparison with cell lines, we discuss factors which may contribute to the relatively low chance of primary HCC engraftment in xenotransplantation models and comment on technical issues that may influence the kinetics of xenograft growth. We also suggest methods that should be applied to ensure that xenografts obtained accurately resemble parent HCC tissues.

Mitochondrial KATP channels in hindlimb remote ischemic preconditioning of skeletal muscle against infarction.

We previously demonstrated in the pig that instigation of three cycles of 10 min of occlusion and reperfusion in a hindlimb by tourniquet application (approximately 300 mmHg) elicited protection against ischemia-reperfusion injury (infarction) in multiple distant skeletal muscles subsequently subjected to 4 h of ischemia and 48 h of reperfusion, but the mechanism was not studied. The aim of this project was to test our hypothesis that mitochondrial ATP-sensitive potassium (KATP) (mKATP) channels play a central role in the trigger and mediator mechanisms of hindlimb remote ischemic preconditioning (IPC) of skeletal muscle against infarction in the pig. We observed in the pig that hindlimb remote IPC reduced the infarct size of latissimus dorsi (LD) muscle flaps (8 x 13 cm) from 45 +/- 2% to 22 +/- 3% (n = 10; P < 0.05). The nonselective KATP channel inhibitor glibenclamide (0.3 mg/kg) or the selective mKATP channel inhibitor 5-hydroxydecanoate (5-HD, 5 mg/kg), but not the selective sarcolemmal KATP (sKATP) channel inhibitor HMR-1098 (3 mg/kg), abolished the infarct-protective effect of hindlimb remote IPC in LD muscle flaps (n = 10, P < 0.05) when these drugs were injected intravenously at 10 min before remote IPC. In addition, intravenous bolus injection of glibenclamide (1 mg/kg) or 5-HD (10 mg/kg) at the end of hindlimb remote IPC also abolished the infarct protection in LD muscle flaps (n = 10; P < 0.05). Furthermore, intravenous injection of the specific mKATPchannel opener BMS-191095 (2 mg/kg) at 10 min before 4 h of ischemia protected the LD muscle flap against infarction to a similar extent as hindlimb remote IPC, and this infarct-protective effect of BMS-191095 was abolished by intravenous bolus injection of 5-HD (5 mg/kg) at 10 min before or after intravenous injection of BMS-191095 (n = 10; P < 0.05). The infarct protective effect of BMS-191095 was associated with a higher muscle content of ATP at the end of 4 h of ischemia and a decrease in muscle neutrophilic myeloperoxidase activity at the end of 1.5 h of reperfusion compared with the time-matched control (n = 10, P < 0.05). These observations led us to conclude that mKATP channels play a central role in the trigger and mediator mechanisms of hindlimb remote IPC of skeletal muscle against infarction in the pig, and the opening of mKATP channels in ischemic skeletal muscle is associated with an ATP-sparing effect during sustained ischemia and attenuation of neutrophil accumulation during reperfusion.