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In open surgical procedures, image-ablate ultrasound arrays performed thermal ablation and imaging on rabbit liver lobes with implanted VX2 tumor. Treatments included unfocused (bulk ultrasound ablation, N = 10) and focused (high-intensity focused ultrasound ablation, N = 13) exposure conditions. Echo decorrelation and integrated backscatter images were formed from pulse-echo data recorded during rest periods after each therapy pulse. Echo decorrelation images were corrected for artifacts using decorrelation measured prior to ablation. Ablation prediction performance was assessed using receiver operating characteristic curves. Results revealed significantly increased echo decorrelation and integrated backscatter in both ablated liver and ablated tumor relative to unablated tissue, with larger differences observed in liver than in tumor. For receiver operating characteristic curves computed from all ablation exposures, both echo decorrelation and integrated backscatter predicted liver and tumor ablation with statistically significant success, and echo decorrelation was significantly better as a predictor of liver ablation. These results indicate echo decorrelation imaging is a successful predictor of local thermal ablation in both normal liver and tumor tissue, with potential for real-time therapy monitoring.

Background Vascularized composite allografts, particularly hand and forearm, have limited ischemic tolerance after procurement. In bilateral hand transplantations, this demands a 2 team approach and expedited transfer of the allograft, limiting the recovery to a small geographic area. Ex situ perfusion may be an alternative allograft preservation method to extend allograft survival time. This is a short report of 5 human limbs maintained for 24 hours with ex situ perfusion. Methods Upper limbs were procured from brain-dead organ donors. Following recovery, the brachial artery was cannulated and flushed with 10 000 U of heparin. The limb was then attached to a custom-made, near-normothermic (30-33°C) ex situ perfusion system composed of a pump, reservoir, and oxygenator. Perfusate was plasma-based with a hemoglobin concentration of 4 to 6 g/dL. Results Average warm ischemia time was 76 minutes. Perfusion was maintained at an average systolic pressure of 93 ± 2 mm Hg, flow 310 ± 20 mL/min, and vascular resistance 153 ± 16 mm Hg/L per minute. Average oxygen consumption was 1.1 ± 0.2 mL/kg per minute. Neuromuscular electrical stimulation continually displayed contraction until the end of perfusion, and histology showed no myocyte injury. Conclusions Human limb allografts appeared viable after 24 hours of near-normothermic ex situ perfusion. Although these results are early and need validation with transplantation, this technology has promise for extending allograft storage times.

During chronic caloric excess, adipose tissue expands primarily by enlargement of individual adipocytes, which become stressed with lipid overloading, thereby contributing to obesity-related disease. Although adipose tissue contains numerous preadipocytes, differentiation into functionally competent adipocytes is insufficient to accommodate the chronic caloric excess and prevent adipocyte overloading. We report for the first time that a chronic high-fat diet (HFD) impairs adipogenic differentiation, leading to accumulation of inefficiently differentiated adipocytes with blunted expression of adipogenic differentiation-specific genes. Preadipocytes from these mice likewise exhibit impaired adipogenic differentiation, and this phenotype persists during in vitro cell culture. HFD-induced impaired adipogenic differentiation is associated with elevated expression of histone deacetylase 9 (HDAC9), an endogenous negative regulator of adipogenic differentiation. Genetic ablation of HDAC9 improves adipogenic differentiation and systemic metabolic state during an HFD, resulting in diminished weight gain, improved glucose tolerance and insulin sensitivity, and reduced hepatosteatosis. Moreover, compared with wild-type mice, HDAC9 knockout mice exhibit upregulated expression of beige adipocyte marker genes, particularly during an HFD, in association with increased energy expenditure and adaptive thermogenesis. These results suggest that targeting HDAC9 may be an effective strategy for combating obesity-related metabolic disease.

Impaired adipogenic differentiation during diet-induced obesity (DIO) promotes adipocyte hypertrophy and inflammation, thereby contributing to metabolic disease. Adenomatosis polyposis coli down-regulated 1 (APCDD1) has recently been identified as an inhibitor of Wnt signaling, a key regulator of adipogenic differentiation. Here we report a novel role for APCDD1 in adipogenic differentiation via repression of Wnt signaling and an epigenetic linkage between miR-130 and APCDD1 in DIO. APCDD1 expression was significantly up-regulated in mature adipocytes compared with undifferentiated preadipocytes in both human and mouse subcutaneous adipose tissues. siRNA-based silencing of APCDD1 in 3T3-L1 preadipocytes markedly increased the expression of Wnt signaling proteins (Wnt3a, Wnt5a, Wnt10b, LRP5, and β-catenin) and inhibited the expression of adipocyte differentiation markers (CCAAT/enhancer-binding protein α (C/EBPα) and peroxisome proliferator-activated receptor γ (PPARγ)) and lipid droplet accumulation, whereas adenovirus-mediated overexpression of APCDD1 enhanced adipogenic differentiation. Notably, DIO mice exhibited reduced APCDD1 expression and increased Wnt expression in both subcutaneous and visceral adipose tissues and impaired adipogenic differentiation in vitro. Mechanistically, we found that miR-130, whose expression is up-regulated in adipose tissues of DIO mice, could directly target the 3′-untranslated region of the APCDD1 gene. Furthermore, transfection of an miR-130 inhibitor in preadipocytes enhanced, whereas an miR-130 mimic blunted, adipogenic differentiation, suggesting that miR-130 contributes to impaired adipogenic differentiation during DIO by repressing APCDD1 expression. Finally, human subcutaneous adipose tissues isolated from obese individuals exhibited reduced expression of APCDD1, C/EBPα, and PPARγ compared with those from non-obese subjects. Taken together, these novel findings suggest that APCDD1 positively regulates adipogenic differentiation and that its down-regulation by miR-130 during DIO may contribute to impaired adipogenic differentiation and obesity-related metabolic disease.

Chronic hepatitis C virus (HCV) is the most common disease indication for liver transplantation (LT). Outcomes are compromised by near universal recurrence of HCV. A prospective multi-center randomized study to evaluate immunosuppressive strategies in HCV+ transplant recipients provided the opportunity to assess impact of live donor (LD) LT. Two hundred and ninety-five patients undergoing LT for HCV (260 deceased donor [DD] recipients/35 LD recipients), randomized to three regimens, were followed for two yr for patient and graft survival and rate and severity of recurrent HCV. Biopsies were performed at baseline, 3, 12, and 24 months. One- and two-yr patient survival for LD recipients was 88.1% and 81.1% vs. 90.5% and 84.6% for DD recipients (p = 0.5665). One- and two-yr graft survival for LD recipients was 82.9% and 76.2% vs. 87.9% and 81.7% for DD recipients (p = 0.3921). Recurrent HCV did not account for more deaths or graft losses in the LD recipients. In this prospective study, controlled for immunosuppression, use of LD organs did not increase the rate or severity of HCV recurrence. The more elective nature of LDLT affords an opportunity to manipulate donor and recipient factors that can impact upon outcomes.

In the preclinical studies reported here, VX2 cancer within rabbit liver has been treated by bulk ultrasound ablation employing miniaturized image-ablate arrays. Array probes were constructed with 32 elements in a 2.3 × 20 mm(2) aperture, packaged within a 3.1 mm stainless steel tube with a cooling and coupling balloon for in vivo use. The probes were measured capable of 50% fractional bandwidth for pulse-echo imaging (center frequency 4.4 MHz) with >110 W/cm(2) surface intensity available at sonication frequencies 3.5 and 4.8 MHz. B-scan imaging performance of the arrays was measured to be comparable to larger diagnostic linear arrays, although nearfield image quality was reduced by ringdown artifacts. A series of in vivo ablation procedures was performed using an unfocused 32-element aperture firing at 4.8 MHz with exposure durations 20-70.5 s and in situ spatial average, temporal average intensities 22.4-38.5 W/cm(2). Ablation of a complete tumor cross-section was confirmed by vital staining in seven of 12 exposures, with four exposures ablating an additional margin >1 mm beyond the tumor in all directions. Analysis suggests a threshold ablation effect, with complete ablation of tumor cross-sections for exposures with delivery of >838 J acoustic energy. The results show feasibility for in vivo liver cancer ablation using miniaturized image-ablate arrays suitable for interstitial deployment.

Context—Tacrolimus is an immunosuppressant that undergoes therapeutic drug monitoring. The laboratory at our institution changed its immunoassay techniques from the fluorescence polarization immunoassay to the cloned enzyme donation immunoassay.Objective—To evaluate the relationship between the 2 assays and to determine the impact of the change on clinical decision making.Design—A retrospective study of patients admitted to the hospital during the assay transition period. Tacrolimus values for the 2 assays were collected for 4 weeks and compared.Setting—An academic health center.Patients—Liver transplant patients hospitalized from February 18, 2008, to March 18, 2008.Main Outcome Measure—The primary outcome was the agreement between the results of the 2 immunoassays. Secondary outcome was agreement of clinical decision making with established patient-specific therapeutic ranges or with a 30% difference in absolute values between the assays.Results—Seventy-nine pairs of tacrolimus concentrations were colle...

Adipose tissue depots originate from distinct precursor cells, are functionally diverse, and modulate disease processes in a depot-specific manner. However, the functional properties of perivascular adipocytes, and their influence on disease of the blood vessel wall, remain to be determined. We show that human coronary perivascular adipocytes exhibit a reduced state of adipocytic differentiation as compared with adipocytes derived from subcutaneous and visceral (perirenal) adipose depots. Secretion of antiinflammatory adiponectin is markedly reduced, whereas that of proinflammatory cytokines interleukin-6, interleukin-8, and monocyte chemoattractant protein-1, is markedly increased in perivascular adipocytes. These depot-specific differences in adipocyte function are demonstrable in both freshly isolated adipose tissues and in vitro–differentiated adipocytes. Murine aortic arch perivascular adipose tissues likewise express lower levels of adipocyte-associated genes as compared with subcutaneous and visceral adipose tissues. Moreover, 2 weeks of high-fat feeding caused further reductions in adipocyte-associated gene expression, while upregulating proinflammatory gene expression, in perivascular adipose tissues. These changes were observed in the absence of macrophage recruitment to the perivascular adipose depot. We conclude that perivascular adipocytes exhibit reduced differentiation and a heightened proinflammatory state, properties that are intrinsic to the adipocytes residing in this depot. Dysfunction of perivascular adipose tissue induced by fat feeding suggests that this unique adipose depot is capable of linking metabolic signals to inflammation in the blood vessel wall.

Objective The purpose of this study was to test ultrasound echo decorrelation imaging for mapping and characterization of tissue effects caused by radio frequency ablation (RFA). Methods Radio frequency ablation procedures (6-minute duration, 20-W power) were performed on fresh ex vivo bovine liver tissue (n = 9) with continuous acquisition of beam-formed ultrasound echo data from a 7-MHz linear array. Echo data were processed to form B-scan images, echo decorrelation images (related to rapid random changes in echo waveforms), and integrated backscatter images (related to local changes in received echo energy). Echo decorrelation and integrated backscatter values at the location of a low-noise thermocouple were assessed as functions of temperature. Echo decorrelation and integrated backscatter images were directly compared with ablated tissue cross sections and quantitatively evaluated as predictors of tissue ablation and overtreatment. Results Echo decorrelation maps corresponded with local tissue temperature and ablation effects. Consistent echo decorrelation increases were observed for temperatures above 75 degrees C, whereas integrated backscatter maps showed a nonmonotonic temperature dependence complicated by acoustic shadowing, with high variance at large temperature elevations. In receiver operating characteristic curve analysis of echo decorrelation and integrated backscatter maps as predictors of local tissue ablation, echo decorrelation performed well (area under the receiver operating characteristic curve [AUROC] = 0.855 for ablation and 0.913 for overtreatment), whereas integrated backscatter performed poorly (AUROC Conclusions Echo decorrelation imaging can map tissue changes due to RFA in vitro, with local echo decorrelation corresponding strongly to local tissue temperature elevations and ablation effects. With further development and in vivo validation, echo decorrelation imaging is potentially useful for improved image guidance of clinical RFA procedures.

Transplant patients are at increased risk of developing dyslipidemia, which contributes to coronary artery disease and cardiovascular events. The purpose of this study was to explore documented adverse effects of liver transplant recipients receiving lipid-lowering therapies. Methods: A retrospective chart review of 69 liver transplant patients was conducted to evaluate the incidence of adverse effects, especially rhabdomyolysis and liver function abnormalities, in liver transplant patients treated with a lipid lowering agent (LLA). Data were collected from the time of initiation of LLA to 12 months later, looking at the type, dose, and duration of LLA, concurrent cytochrome P450 inhibitors, immunosuppression used, and laboratory parameters. Results: For HMG-CoA reductase inhibitor therapy, simvistatin was used in five (7.8%) patients, pravastatin in 40 (62.5%), fluvastatin in one (1.6%), atorvastatin in five (7.8%), and lovastatin in three (4.7%). Gemfibrozil, a fibric acid derivative, was employed as monotherapy in 10 (15.6%) of patients. There were five patients who received combination therapy with a fibric acid derivative, four (80%) with gemfibrozil + pravastatin, and one (20%) with gemfibrozil + simvastatin. Six patients studied had adverse effects, five (7.2%) with myalgia and one (1.4%) with myopathy. LLA monotherapy with either pravastatin or atorvastatin was used in these patients. The five patients with myalgia were on concurrent therapy with cyclosporin, and the patient with myopathy was on concurrent cyclosporin + diltiazem therapy, both of which are P450 inhibitors. One out of 23 patients on a non-immunosuppressant P450 inhibitor developed adverse effects. No significant elevation of alanine aminotransferase, aspartate aminotransferase, or alkaline phosphatase was noted in any patient. Conclusions: Overall, there was a general tolerability with a low incidence of adverse events, no incidence of severe complications, and no alterations in liver function tests in the study population with the use of LLA.

In at-risk populations, shared routes of transmission lead to high rates of concordance between infection with human immunodeficiency virus (HIV) type 1 and hepatitis C virus (HCV). In the era of highly active antiretroviral therapy (HAART), end-stage liver disease (ESLD) has emerged as a leading cause of mortality in coinfected patients. HAART-related toxicities have been implicated, especially when given to patients with viral hepatitis. Rates of response to treatment for HCV infection in coinfected patients continue to lag behind those in monoinfected patients, even with the advent of pegylated interferons. Liver transplantation has been approached with caution in this population because of concern about the sequelae of immunosuppression and HAART-related hepatotoxicity, and results have been conflicting. Clinical and serological markers of ESLD in coinfected patients, management of cirrhosis, and the appropriateness of transplantation are discussed.

Since the introduction of the laparoscopic cholecystectomy, there has been explosive growth in the field of minimally invasive surgery. Commonly accepted laparoscopic procedures have now come to include bariatric and anti reflux procedures, distal pancreatectomy, splenectomy, hernia repair, and colon resection. The adoption of laparoscopy to the field of liver surgery; however, has been slower to take off. Initial concerns included inadequate exposure and ability to attain hemostasis, fear of gas embolism, and doubts over the oncologic adequacy of the less invasive procedure. The earliest reports of laparoscopic liver surgery were limited to wedge resections for staging or isolated metastases(Lefor, AT & Flowers, JL 1994). Laparoscopic liver resection finally started to gain serious widespread attention after publication of Cherqui’s initial thirty patient experience(Cherqui, D et al 2000). Since that time, the field has seen explosive growth, with over 2,804 cases now described in the world literature(Nguyen, KT et al 2009). Despite its widespread acceptance, laparoscopic liver resection remains a daunting technical challenge suited to a relatively small number of centers that have taken the time and effort to develop concurrent expertise in both open hepatic surgery and laparoscopy. Once these hurdles are overcome; however, laparoscopic liver resection is a safe and highly effective procedure offering numerous patient benefits. In this chapter, we will describe the indications for laparoscopic liver resection, and outline the steps that should be taken by fledgling groups wishing to embark upon creating a laparoscopic liver resection program.

Background. This study evaluated the efficacy of a protocol of initial balloon dilation for biliary strictures after liver transplantation. Methods. Complete records from 96 patients with biliary strictures were retrospectively reviewed. Seventy-six patients received percutaneous transhepatic balloon cholangioplasty (PTBC) after initial placement of biliary drainage (percutaneous transluminal cholangiography [PTC]) tube. In most cases, three dilations were performed with a 4 to 8 week interval between procedures. Follow-up ranged from 6 months to 10 years. Results. PTBC successfully treated strictures in 39 of 76 (51.3%) cases. Factors favoring successful PTBC included older age at transplant, shorter cold ischemic time, and single strictures. There were nine recurrent strictures after PTBC, all of which were successfully treated by nonoperative measures. The number of dilations performed affected both the likelihood of success and the long-term risk of stricture recurrence. Of the 37 PTBC failures, 14 underwent subsequent surgical revision. When both angiographic and surgical modalities were considered, treatment success was associated with first transplants, shorter cold ischemic time and operative time, and less intraoperative transfusion requirements. Factors associated with treatment failure included multiple, central hepatic duct, and intrahepatic strictures. PTC-tube independence was achieved in 51 of 76 (67%) patients using the combined approach of PTBC and surgery for PTBC failures. Conclusions. PTBC is an effective initial modality for treating posttransplant biliary strictures. Prolonged cold ischemic and operative times and multiple or peripheral strictures predispose to treatment failure. Solitary extrahepatic strictures that fail PTBC are salvageable with surgical revision with excellent results.

Hepatitis C virus (HCV) is becoming the most common indication for liver retransplantation (ReLTx). This study was a retrospective review of the medical records of liver transplant patients at our institution to determine factors that would identify the best candidates for ReLTx resulting from allograft failure because of HCV recurrence. The patients were divided into 2 groups on the basis of indication for initial liver transplant. Group 1 included ReLTx patients whose initial indication for LTx was HCV. Group 2 included patients who received ReLTx who did not have a history of HCV. We defined chronic allograft dysfunction (AD) as patients with persistent jaundice (> 30 days) beginning 6 months after primary liver transplant in the absence of other reasons. HCV was the primary indication for initial orthotopic liver transplantation (OLT) in 491/1114 patients (44%) from July 1996 to February 2004. The number of patients with AD undergoing ReLTx in Groups 1 and 2 was 22 and 12, respectively. The overall patient and allograft survival at 1 year was 50% and 75% in Groups 1 and 2, respectively (P = .04). The rates of primary nonfunction and technical problems after ReLTx were not different between the groups. However, the incidence of recurrent AD was higher in Group 1 at 32% versus 17% in Group 2 (P = .04). Important factors that predicted a successful ReLTx included physical condition at the time of ReLTx (P = .002) and Child-Turcotte-Pugh score (P = .008). In conclusion, HCV is associated with an increased incidence of chronic graft destruction with a negative effect on long-term results after ReLTx. The optimum candidate for ReLTx is a patient who can maintain normal physical activity. As the allograft shortage continues, the optimal use of cadaveric livers continues to be of primary importance. The use of deceased donor livers in patients with allograft failure caused by HCV remains a highly controversial issue. (Liver Transpl 2004;10:1497–1503.)

Nitric oxide generation from porcine kidney slices is assessed using a new planar NO-selective amperometric sensor. The planar shape of the sensor allows for direct NO measurements near the surface (10 μm) of renal tissue slices in real time. Renal NO production may be modulated by the addition of l-arginine, arginine homopolymers (R2, R6, R10), and protamine, all of which can potentially transport across cellular membranes and provide a substrate for nitric oxide synthase within kidney parenchyma. Real-time amperometric measurements demonstrate that most l-arginine species can translocate across the cell membrane and rapidly increase NO production. However, no increase in NO generation is observed when the dimer of l-arginine (R2) is added to the solution bathing the tissue, suggesting that this species cannot permeate cell membranes. The degree of enhancement in NO generation observed for l-arginine and the larger peptides depends on the structure and follows the following sequence: R10 (decamer) > pro...

The widespread use of miniaturized chemical sensors to monitor clinically important analytes such as PO2, PCO2, pH, electrolytes, glucose and lactate in a continuous, real-time manner has been seriously hindered by the erratic analytical results often obtained when such devices are implanted in vivo. One major factor that has influenced the analytical performance of indwelling sensors is the biological response they elicit when in contact with blood or tissue (e.g. thrombus formation on the device surface, inflammatory response, encapsulation, etc.). Nitric oxide (NO) has been shown to be a potent inhibitor of platelet adhesion and activation as well as a promoter of wound healing in tissue. Herein, we review recent work aimed at the development of hydrophobic NO-releasing polymers that can be employed to coat catheter-type amperometric oxygen sensors without interfering with the analytical performance of these devices. Such modified sensors are shown to exhibit greatly enhanced hemocompatibility and improved analytical performance when implanted within porcine carotid and femoral arteries for up to 16 h. Further, results from preliminary studies also demonstrate that prototype fluorescent oxygen sensors, catheter-style potentiometric carbon dioxide sensors and subcutaneous needle-type enzyme-based amperometric glucose sensors can also be fabricated with new NO-release outer coatings without compromising the analytical response characteristics of these devices. The NO-release strategy may provide a solution to the lingering biocompatibility problems encountered when miniature chemical sensors are implanted in vivo.

Background As more expanded-criteria organ donors are used to bridge the widening gap between organ supply and demand, non-heart-beating (NHB) donors will become increasingly important. The purpose of this study was to analyze renal transplant outcomes using this source of cadaveric (CAD) organs and compare the results with heart-beating organ sources. Methods Data from 98,698 adult CAD renal transplant recipients and 34,531 living donor renal transplant recipients registered in the U. S. Renal Data System database between January 1993 and June 2000 were analyzed. Kaplan-Meier survival curves were used to compare graft and patient survival rates between NHB, CAD, and living donor transplant recipients. Cox proportional hazards models were used to identify risk factors for NHB donor recipients, while adjusting for potential confounding variables. Results Recipients of NHB donor organs experienced nearly twice the incidence of delayed graft function (DGF) compared with heart-beating donors (42.4% vs. 23.3%, respectively). NHB donor transplants experienced comparable allograft survival when compared with CAD transplants at 6 years (73.2% vs. 72.5%, respectively; P=NS); patient survival was greater at 6 years for NHB compared with CAD renal transplant recipients (80.9% vs. 77.8%, respectively; P=NS). Significant factors for allograft loss for NHB donor organ recipients included the following: organ used for repeat transplants; DGF; donor age older than 35 years; and head trauma as a cause of initial injury (relative risk 2.74, 1.90, 1.78, and 1.41, respectively). Conclusions Although exhibiting elevated DGF rates, allograft and patient survival rates of transplants from NHB donor sources are equivalent to those from conventional CAD sources. Donor age, recipient transplant number, female recipient, mechanism of injury, and DGF were the most pertinent variables leading to poor outcomes.

The in vivo biocompatibility and analytical performance of amperometric oxygen-sensing catheters prepared with a new type of nitric oxide (NO)-releasing silicone rubber polymer (DACA/N2O2 SR) is reported. The NO-release silicone rubber coating contains diazeniumdiolated secondary amine sites covalently anchored to a dimethylsiloxane matrix. Narrow diameter (0.9 mm, o.d.) silicone rubber tubing coated with this polymer can be employed to construct functional oxygen-sensing catheters that release NO continuously at levels1 x 10(-10) mol/cm2-min for more than 20 h. In vivo evaluation of such sensors within the carotid and femoral arteries of swine over a 16-h time period demonstrates that sensors prepared with the new NO-release coating exhibit no significant platelet adhesion or thrombus formation, but control sensors (non-NO release) implanted within the same animals do show a high propensity for cell adhesion and bulk clot formation. Furthermore, the in vivo analytical data provided by sensors fabricated with NO-release coatings (N = 9) are shown to be statistically equivalent to PO2 levels measured in vitro on discrete samples of blood. Control sensors (N = 9) placed within the same animals yield average PO2 values that are statistically different (por = 0.05) (lower) from both the levels measured on discrete samples and those provided by the NO-release sensors over a 16-h in vivo monitoring period.

Background. Previous studies have shown more women than men among living donors (LD) and more men among recipients of those kidneys. In this study, we compared the evolving demographics of LD transplants. Methods. We retrospectively analyzed all LD transplants performed in our center between 1964 and 2000. Results. Among 1182 LD cases, 1035 (88%) were biologically related (LRD) and 147 (12%) were unrelated (LURD). LURD donors and recipients were significantly older than LRD donors and recipients, respectively (P=0.0001). More LURD allograft recipients were male (71%) compared with LRD recipients (57%) (P=0.0013). The proportion of female donors was 55% in both groups. Spousal donations were predominantly wife-to-husband (69%). Compared with the LRD group, there was a greater proportion of female-to-male LURD transplants (46 vs. 30%) and a smaller proportion of female-to-female LURD transplants (10 vs. 25%) (P=0.0001). When spousal pairs were excluded from the analysis, there was a higher proportion of male-to-male (48 vs. 27%) donations and a lower proportion of male-to-female (18 vs. 9%) and female-to-female (25 vs. 17%) transplants in the LURD group (P=0.001). ). Conclusions. Gender disparities in LD transplantation are primarily due to a higher proportion of wife-to-husband donations and a lower incidence of male-to-female grafts among nonspousal LURD transplants. Strategies should be devised to ensure access for women to renal transplantation and to encourage and facilitate donation by men.

Introduction. The importance of HLA matching for renal transplantation outcomes has been appreciated for several decades. It has been hypothesized that as pharmacologic immunosuppression becomes stronger and more specific, the impact of HLA matching may be vanishing. Mycophenolate Mofetil (MMF) has been demonstrated to both decrease acute rejection and improve three-year graft survival. It is possible that with new immunosuppressive regimens containing MMF the relative effect of HLA matching may be altered. To determine the relative impact of HLA matching in patients on MMF we undertook an analysis of the United States Renal Transplant Data Registry (USRDS). Methods. All primary, solitary renal transplants registered at the USRDS between January 1995 and June 1997, on initial immunosuppression that included either MMF or AZA were followed until June 1998. Primary study end points were graft and patient survival. Kaplan-Meier analysis was performed to compare AZA vs. MMF treated patients by HLA mismatch. Cox proportional hazard models were used to investigate the interaction between HLA mismatch and AZA versus MMF therapy on the study endpoints. All multivariate analyses were corrected for 13 potential confounding pretransplant variables including intention to treat immunosuppression. Results. A total of 19,675 patients were analyzed (8,459 on MMF and 11,216 on AZA). Overall three year graft survival was higher in the MMF group when compared to the AZA group (87% vs. 84% respectively P

Background. There are presently no established pretransplant tests that consistently identify patients who may be at increased risk for acute rejection episodes after renal transplantation. We studied whether pretransplant serum levels of C-reactive protein (CRP), a marker for the presence of systemic inflammation, would predict the occurrence of acute rejection episodes after renal transplantation. Methods. Pretransplant serum was tested for CRP level in 97 consecutive renal transplant recipients. Time to acute rejection after transplantation was stratified by CRP level and compared using the Kaplan-Meier method. In addition, Cox regression multivariate analysis was performed to assess whether any pretransplant covariates could independently predict the subsequent occurrence of acute rejection episodes. Results. Pretransplant mean CRP levels were higher in patients who subsequently had a rejection episode versus those who had no rejection (22.262.9 vs. 11.761.8 mg/ml, respectively, P50.003). Patients less than the median CRP value had a significantly longer time to rejection compared to those with higher CRP levels (P50.002). Similarly, patients within the lowest CRP quartile had longer times to rejection when compared with the highest quartile (P50.006). Cox proportional hazards regression multivariate analysis identified CRP level as the only independent pretransplant risk factor for rejection identified (P50.044). Conclusions. Pretransplant systemic inflammation as manifested by elevated serum CRP level independently predicts the risk of acute rejection after renal transplantation and may be useful in stratifying patients at the time of transplantation according to immunological risk. Thus, assessment of pretransplant systemic inflammatory status may be helpful in prospective individualization of immunosuppression therapy after renal transplantation.

Living donor renal transplantation has achieved a high level of acceptance from the general public and is the ideal renal replacement therapy for those with end-stage renal disease. Living donor nephrectomy has been proven safe and is associated with minimal complications and a negligible death rate. 1 The recipient benefits of living donor renal transplantation are multiple: superior patient and graft survival, no prolonged waiting time, decreased incidence of delayed allograft function, and a shorter hospital stay. 2 These superior results and the current shortage of cadaver kidneys provide an incentive to increase the frequency of living donor transplantation. However, a significant disincentive is the invasive nature of the donor nephrectomy and its relatively long postoperative recovery period. Recent reports of laparoscopically assisted living donor nephrectomy have shown that this less invasive approach results in reduced postoperative pain, a shorter hospital stay, and a more rapid return to the work for the donor. 3–6 In addition, decreased donor discomfort and a shorter convalescence have resulted in a substantially increased rate of consent to living donation and may help to alleviate the ongoing transplant organ shortage. A critical analysis with regard to the rate of donor complications and death and the status of the procured kidney is needed before laparoscopic living donor nephrectomy can be fully accepted by the transplant community. In particular, the excellent immediate renal allograft function usually obtained with standard open donor nephrectomy must be reproduced with the laparoscopic technique. A major concern regarding laparoscopic living donor nephrectomy is compelling evidence demonstrating that the prolonged CO2 pneumoperitoneum during laparoscopy decreases renal blood flow and contributes to postoperative renal dysfunction in the recipient. 7,8 The combination of prolonged CO2 pneumoperitoneum and an ischemic period during organ procurement may expose these grafts to an increased risk of early posttransplant renal dysfunction. The purported adverse effects of pneumoperitoneum on renal function have been supported by the initial reports of laparoscopic donor nephrectomy, which suggest either a decrease in urine output during the donor operation or early renal allograft dysfunction. 3,5,6 Gaseous pneumoperitoneum has been found to induce significant systemic hemodynamic alterations that appear to depend on the type of gas, the magnitude of intraabdominal pressure, the baseline hemodynamic function, and intravascular volume status. The cardiovascular effects most frequently associated with CO2 pneumoperitoneum are tachycardia, increased total peripheral resistance, and decreased stroke volume. 8–10 Some investigators have also reported a decrease in cardiac output, but previous studies from our laboratory showed that cardiac output decreased only in hypovolemic animals. 11,12 The effects of intravascular volume expansion on renal blood flow and function during prolonged CO2 pneumoperitoneum remain unknown. Hypertonic saline volume expansion has been shown to improve renal blood flow in other animal models of hypovolemia. 13,14 The use of hypertonic saline solution for volume expansion may provide protection to the kidneys without significant fluid overload to the donor. The objectives of this study were to test the hypothesis that intravascular volume expansion would improve renal blood flow and function during prolonged CO2 pneumoperitoneum, and to compare the beneficial effects of volume expansion on renal hemodynamics using isotonic (normal saline) and hypertonic (2400 mOsm NaCl) solutions.

Background. Enhanced Kupffer cell production of the immunosuppressive arachidonic acid metabolite prostaglandin E 2 (PGE 2 ) has been shown to be a mechanism of the immunosuppressive effect of portal venous transfusions (PVT). Butyrate, a four-carbon short-chain fatty acid, has received increased attention because of its ability to enhance gene transcription. This study tested the hypothesis that the intrahepatic delivery of butyrate enhances Kupffer cell PGE 2 production and thus augments the immunosuppressive effect of PVT. Methods. Butyrate was incorporated into liposomes and administered intravenously to Lewis rats. Control rats were administered liposomes without butyrate. Twenty-four hours after liposome injection, rats were administered a PVT of 1 ml of Wistar-Furth blood. Kupffer cells were isolated, and PGE 2 and tumor necrosis factor-α levels were measured in the culture medium after 24 hr. Additionally, Kupffer cells from butyrate-treated and control animals were added to one-way mixed lymphocyte reaction cultures. Results. Intrahepatic delivery of butyrate via liposomes increased Kupffer cell PGE 2 (3800±1220 vs. 1010±119 pg/ml, P

Inflammatory cross talk between perivascular adipose tissue and the blood vessel wall has been proposed to contribute to the pathogenesis of atherosclerosis. We previously reported that human perivascular (PV) adipocytes exhibit a proinflammatory phenotype and less adipogenic differentiation than do subcutaneous (SQ) adipocytes. To gain a global view of the genomic basis of biologic differences between PV and SQ adipocytes, we performed genome-wide expression analyses to identify differentially expressed genes between adipocytes derived from human SQ vs. PV adipose tissues. Although >90% of well-expressed genes were similarly regulated, we identified a signature of 307 differentially expressed genes that were highly enriched for functions associated with the regulation of angiogenesis, vascular morphology, inflammation, and blood clotting. Of the 156 PV upregulated genes, 59 associate with angiogenesis, vascular biology, or inflammation, noteworthy of which include TNFRSF11B (osteoprotegerin), PLAT, TGFB1, THBS2, HIF1A, GATA6, and SERPINE1. Of 166 PV downregulated genes, 21 associated with vascular biology and inflammation, including ANGPT1, ANGPTL1, and VEGFC. Consistent with the emergent hypothesis that PV adipocytes differentially regulate angiogenesis and inflammation, cell culture-derived adipocyte-conditioned media from PV adipocytes strongly enhanced endothelial cell tubulogenesis and monocyte migration compared with media from SQ adipocytes. These findings demonstrate that PV adipocytes have the potential to significantly modulate vascular inflammatory crosstalk in the setting of atherosclerosis by their ability to signal to both endothelial and inflammatory cells.

The angiotensinogen gene is genetically linked with hypertension, but the mechanistic basis for association of sequence variants in the promoter and coding region of the gene remains unclear. An E-box at position −20 has been hypothesized to control the level of angiotensinogen expression, but its mechanistic importance for angiotensinogen expression in human tissues is uncertain. We developed an allele-specific polymerase chain reaction–based assay to distinguish between angiotensinogen mRNA derived from variants at the −20 position (rs5050) in the angiotensinogen promoter in adipose tissues obtained during surgery. The assay takes advantage of linkage disequilibrium between the rs5050 (located in the promoter) and rs4762 (located in the coding region) single nucleotide polymorphisms. This strategy allowed us to assess the level of allele-specific expression in A-20C heterozygous subjects comparing the relative proportion of each allele with the total, thus eliminating the problem of variability in the level of total angiotensinogen mRNA among subjects. We show that angiotensinogen mRNA derived from the −20C allele is expressed significantly higher than that derived from the −20A allele in subcutaneous adipose tissue, and increased expression correlates with enriched chromatin binding of upstream stimulatory factor-2 to the −20C E-box compared with −20A. This may be depot selective because we were unable to detect these differences in omental adipose. This provides the first data directly comparing expression of angiotensinogen mRNA and differential transcription factor binding derived from 2 variant alleles in human tissue where the ratio of expression of one allele to another can be accurately determined

OBJECTIVE: The authors analyze a single center's 11-year experience with 190 orthotopic liver transplants for congenital biliary atresia. SUMMARY BACKGROUND DATA: Hepatic portoenterostomy generally is the initial treatment for children with congenital biliary atresia. Despite multiple modifications of the hepatic portoenterostomy, two thirds of treated patients still develop recurrent cholestasis, portal hypertension, cholangitis, and cirrhosis. Therefore, the only hope of long-term survival in the majority of children with congenital biliary atresia is definitive correction with orthotopic liver transplantation. METHODS: The medical records of 190 consecutive patients undergoing orthotopic liver transplantation for congenital biliary atresia from July 1, 1984 to February 29, 1996 were reviewed. Results were analyzed via Cox multivariate regression analysis to determine the statistical strength of independent associations between pretransplant covariates and patient and graft survival. Actuarial patient and graft survival was determined at 1, 2, and 5 years. The type and incidence of post-transplant complications were determined, as was the quality of long-term graft function. The median follow-up period was 3.21 years. RESULTS: The liver grafts were comprised on 155 whole-organ, 24 reduced-size, and 11 living donor organs. Median pretransplant values for recipient age, weight, and total bilirubin were 1.4 years, 12.3 kg, and 13.8 mg/dL, respectively. One hundred sixty-four patients (86%) had undergone prior hepatic portoenterostomy. Eighty-seven patients (46%) were United Network for Organ Sharing (UNOS) status 1 or 2 at the time of liver transplantation. The majority (15/24, 62%) of reduced-size graft recipients were UNOS status I at the time of transplantation. One hundred fifty-nine patients (84%) received a single graft, whereas 31 patients required 37 retransplants. The 1, 2, and 5 year actuarial patient survival rates were 83%, 80% and 78% respectively, whereas graft survival rates were 81%, 77%, and 76%, respectively. Cox multivariate regression analysis demonstrated that pretransplant total bilirubin, UNOS status, and graft type significantly predicted patient survival, whereas recipient age, weight, and previous hepatic portoenterostomy did not. Current median follow-up values for total bilirubin and aspartate aminotransferase levels in the 154 surviving patients were 0.5 mg/dL and 34 international units/L, respectively. CONCLUSION: Long-term patient survival after orthotopic liver transplantation for congenital biliary atresia is excellent and is independent of recipient age, weight, or previous hepatic portoenterostomy. Optimal results are obtained in this patient population when liver transplantation is performed before marked hyperbilirubinemia, and when possible, using a living-donor graft.

The ligand-receptor binding requirements for achieving full B cell activation through the membrane immunoglobulin (mIg) signaling pathway are relatively demanding, and mIg-antigen engagements which fall below these critical thresholds cause, at most, only the partial activation of B cells. In an effort to resolve new means of enhancing the efficacy of mIgM-mediated signal transduction, as well as to further understand the process by which mIgM-mediated signals are initiated, we have explored the mechanism for a previously reported synergy between certain mixtures of murine anti-IgM mAbs in eliciting human B cell DNA synthesis. We here report that striking synergy occurs when any of several relatively high affinity mAbs specific for diverse domains of mIgM are combined in culture with the relatively low affinity C mu 4-specific ligand, mAb IG6. Although B cell activation was dependent upon the bivalency, and hence mIgM cross-linking potential, of the high affinity ligand, low affinity mAb IG6 could enhance the activation process when present as a monovalent Fab' fragment. This did not appear due to F(ab')2 contamination or Fab' aggregation, since IG6 Fab' preparations were notably compromised in several other functions requiring ligand bivalency. Pulsing studies revealed that the C mu 4-specific ligand exhibits its functional effects only when stimulatory mIgM receptor cross-links are being formed by bivalent ligands, and that IG6 Fab' enhancement is most notable during the later interval of the prolonged mIgM signaling process that leads to S phase entry. A unique region of the membrane-proximal IgM domain may be important for Fab'-mediated enhancement, since Fab' fragments that bind with higher affinities to distinct sites on C mu 4 were not as effective at mediating this phenomenon. Several possibilities for the adjuvant effects of this C mu 4-specific Fab' on B cell responses triggered by mIgM crosslinking ligands are discussed, including the possibility that IG6 Fab' influences the potential for mIgM dimer formation or interactions of mIgM with other signal-transducing molecules.

The mechanism by which single nucleotide polymorphisms (SNP) regulate angiotensinogen (AGT) expression in humans has been extensively studied but remains unclear. The E box ( C ACGTG) at position -20 in the human AGT promoter binds USF1 and USF2 in vitr o. Recently, we published that USF1 and USF2 are both essential for human AGT expression in double transgenic mice carrying a -20C SNP in human AGT and a gene trap USF1 knockdown. Therefore, we hypothesize that selective binding of USF1/2 to -20C versus -20A (the rs5050 SNP) in the promoter region underlies the enhanced expression of AGT in humans containing the rs5050 SNP. We genotyped subcutaneous adipose tissue from 89 anonymous human donors for both the A-20C SNP and a coding region SNP known to be in linkage disequilibrium with the A-20C (C620T; rs4762). Based on sequencing and TOPO TA cloning, 22% of the samples were heterozygous for A-20C and linkage disequilibrium between -20A with 620C and -20C with 620T was confirmed in 80% of the samples. AGT and USF2 mRNA was elevated significantly (2.0±0.3 and 2.2±0.4 fold, n=8, respectively) in the male -20AC compared to the -20AA group, whereas expression of fatty acid synthase, a known USF target gene, was unchanged. These changes in expression were not observed in females, suggesting sexual dimorphism in the regulation of both USF1/2 and AGT. We developed and validated a quantitative PCR assay using Taqman probes selective for the mRNA separately corresponding to 620T and 620C. We used this assay on RNA derived from 16 heterozygous (-20AC and 620CT) subcutaneous adipose samples. Expression derived from the -20C promoter (620T mRNA) was 4.1±0.6 fold higher compared to the -20A promoter (620C mRNA) (n=16). We have also developed a quantitative allele-specific assay to measure USF1/2 binding to -20AC for use in ChIP. We conclude that USF1/2 and the -20C SNP play physiological roles in AGT regulation in human adipose tissue which we hypothesize is due to increased USF recruitment at -20C.

Background We sought to determine the outcome predictors of 94 cirrhotic patients undergoing laparoscopic cholecystectomy (LC). Methods We performed a single-center, retrospective review of cirrhotic patients undergoing LC for symptomatic gallbladder disease. Statistical analysis was completed using the Chi-square, Wilcoxon rank-sum, and Student t tests as appropriate. Results Ninety-four procedures were completed. The median Child-Turcotte-Pugh (CTP) score was 6 (range, 5–12), and the average Model for End-Stage Liver Disease (MELD) score was 11 ± 5. Hepatitis C was the most common etiology of liver disease (50%) followed by Laennec's cirrhosis (22%). The average length of stay was 2.6 ± 4.3 days; 21% were outpatient procedures. The conversion rate was 11%. Conversion risk factors were decreased serum albumin, increased MELD score, and blood loss. Morbidity occurred in 32 patients. Predictors of morbidity were decreases in serum albumin, increases in International Normalized Ratio (INR) and CTP score, and the number of intraoperative red blood cell transfusions. Mortality occurred in 4 patients. Increased INR, CTP score, CTP class, the number of intraoperative blood and platelet transfusions were predictors of mortality. Conclusion LC can be safely performed in cirrhotic patients with appropriate patient selection. Liver synthetic function, operative blood loss, transfusion requirement, CTP, and MELD scores may be used to predict outcomes in these patients.

VX2 rabbit liver cancer, treated in vivo using bulk ultrasound ablation by miniaturized image-ablate arrays, was histologically analyzed using TTC vital stain and DAPI nucleic acid stain. VX2 cells were implanted into rabbit liver lobes and allowed to grow for 11-21 days. Liver lobes containing solid VX2 tumors were then treated with 4.8 MHz, 22.5-38.5 W/cm2 in situ intensity, unfocused ultrasound for exposure times of 20-120 s. After animal sacrifice, thermal lesions were bisected along the imaging/treatment plane, one face stained with TTC, and the other with DAPI. Levels of TTC uptake (no uptake, partial uptake, and complete uptake) in liver parenchyma corresponded to three discrete regions of tan, pink and red color. By processing images of DAPI-stained parenchymal tissue from these three regions, cellular damage was quantified. A viability index parameter incorporating the size and shape of DAPI-stained nuclei correlated significantly with levels of TTC uptake, and thus with local tissue viability. F...

In the studies reported here, the ability of echo decorrelation imaging to predict thermal ablation in vivo is tested. Radiofrequency ablation (RFA) was performed on a normal swine liver (N=5) and ultrasound ablation using image-ablate arrays was performed on a rabbit implanted with VX2 tumors (N=3). Echo decorrelation imaging was able to predict ablation and overtreatment with high accuracy for both RFA and ultrasound ablation. The effect of tissue motion was studied by comparing the mean cumulative decorrelation with and without treatment. The mean cumulative decorrelation with treatment was found to be significantly greater than the mean cumulative decorrelation without treatment (p=0.0347 for RFA, p=0.024 for ultrasound ablation). The accuracy of ablation predictions was tested using receiver operating characteristic curves and the area under the ROC curve (AUROC) was significant for ablation and overtreatment for RFA (N=5). However, the AUROC was significant for only detecting ablation for the ultras...

To examine the concept of random generation in bounded, as opposed to expected, polynomial time, a model of a probabilistic Turing machine (PTM) with the ability to make random choices with any (small) rational bias is necessary. This ability is equivalent to that of being able to simulate rolling any k-sided die (where [k] is polynomial in the length of the input). We would like to minimize the amount of hardware required for a machine with this capability. This leads to the problem of efficiently simulating a family of dice with a few different types of biased coins as possible. In the special case of simulating one n-sided die, we prove that only two types of biased coins are necessary, which can be reduced to one if we allow irrationally biased coins. This simulation is efficient, taking O(log n) coin flips. For the general case we get a tight time vs number of biases tradeoff; for example, with O(log n) different biases, we can simulate, for any i < n, an i-sided die in O(log n) coin flips.

Nonalcoholic fatty liver disease (NAFLD) refers to an increasingly diagnosed condition involving triglyceride accumulation in hepatocytes, resulting in a broad spectrum of liver injury. This injury ranges from simple hepatic steatosis, steatohepatitis, and chronic fibrosis to cirrhosis, and pathologically resembles alcoholic hepatitis in individuals without extensive alcohol use.1 This disease process has become progressively more prevalent and it is important that clinicians are fully aware of its pathophysiology and clinical implications. The term nonalcoholic fatty liver disease was introduced by Schaffner and Thaler2 in 1986 and is the current terminology used to describe a progressive spectrum of liver disease beginning with simple steatosis and leading to non-alcoholic steatohepatitis (NASH), fibrosis, and ultimately, cirrhosis (Fig. 1). Figure 1 Histologic progression of nonalcoholic fatty liver disease from simple steatosis to cirrhosis. The term nonalcoholic steatohepatitis was coined by Ludwig and colleagues3 in 1980 to describe a cohort of 20 patients with no history of alcohol abuse but with liver biopsies demonstrating fatty change, lobular inflammation, focal necrosis, and Mallory bodies consistent with alcoholic hepatitis. These patients were predominantly female and moderately obese. Nonalcoholic steatohepatitis is the term currently used to describe patients in whom simple steatosis has progressed to histologic evidence of inflammation, including hepatocyte ballooning, mixed acute and chronic lobular inflammation, and zone 3 perisinusoidal fibrosis.4,5 Progression of NAFLD, a relatively benign condition, to NASH is characterized by hepatic infiltration of inflammatory cells and subsequent hepatocellular injury. This inflammatory phase distinguishes NASH from simple NAFLD.6,7 Recent clinical observations have shown a clear link between development of NASH and presence of the metabolic syndrome. The metabolic syndrome is defined as insulin resistance, hypertension, dyslipidemia, and visceral obesity,8–11 and some have suggested that NAFLD be considered an additional feature of the metabolic syndrome.12 There is evidence that inflammatory changes seen in the metabolic syndrome might be an important feature of the progression of NAFLD to NASH. Obesity and insulin resistance have been found to be associated with a chronic state of systemic inflammation involving abnormal cytokine release, secondary mediators, and signaling pathways.13–15 The pathophysiology of the progression of NAFLD to NASH has yet to be fully elucidated. The first insult is the production and accumulation of triglycerides in the liver. This is primarily due to the presence of insulin resistance and hyperinsulinemia resulting in dysregulated lipogenesis and lipolysis peripherally and increased hepatic fatty acid synthesis.16 This results in simple steatosis. Progression to NASH is thought to evolve by way of a “2-hit” phenomenon17 (Fig. 2). The primary insult is lipid accumulation leading to development of steatosis, and the second is oxidative stress and lipid peroxidation resulting in cytokine-mediated recruitment and retention of inflammatory cells. Multiple cytokines, chemokines, and adipokines have been implicated in the development of NASH, including leptin,18–21 adiponectin,21,22 tumor necrosis factor–α,23,24 resistin,25,26 interluekin-6,27 and others. Figure 2 Progression of nonalcoholic fatty liver disease demonstrating the 2-hit hypothesis. The first hit consists of lipid accumulation resulting in simple benign steatosis. This primes the liver for a second hit, which can be multifactorial. This 2-hit process ...

How to represent a graph in memory is a fundamental data structuring question. In the usual representations of an n-vertex graph, the names of the vertices (i.e., integers from 1 to n) betray nothing about the graph itself. Indeed, the names (or labels) on the n vertices are just $\log n$ bit place holders to allow data on the edges to encode the structure of the graph. In this scenario, there is no such waste. By assigning $O(\log n)$ bit labels to the vertices, the structure of the graph is completely encoded, so that, given the labels of two vertices, one can test if they are adjacent in time linear in the size of the labels. Furthermore, given an arbitrary original labeling of the vertices, structure coding labels are found (as above) that are no more than a small constant factor larger than the original labels. These notions are intimately related to vertex-induced universal graphs of polynomial size. For example, planar graphs can be labeled with structure coding labels of size $ < 4\log n$, which i...

In the preclinical studies reported here, VX2 cancer within rabbit liver has been treated by bulk ultrasound ablation employing miniaturized image-ablate arrays. Array probes were constructed with 32 elements in a 2.3×20 mm2 aperture and employed for B-scan imaging as well as bulk ablation at 4.8 MHz. In a series of in vivo experiments, tumor ablation using these arrays was histologically confirmed, with complete ablation of tumor cross sections for exposures with delivery of ≫747 J acoustic energy. These results show feasibility for development of an image-guided, interstitial bulk ultrasound ablation approach for clinical liver cancer treatment.

Hepatic artery thrombosis remains one of the most serious complications after orthotopic liver transplantation. Sepsis, biliary leakage and strictures, and retransplantation are often the result of this devastating complication. Because retransplantation or reoperation is sometimes not possible or advisable, other means of reestablishing hepatic artery continuity are desirable. We describe a liver transplant recipient who developed a dissection of an iliac artery conduit after retransplantation that was treated with fibrinolytic therapy followed by successful placement of an endovascular stent.

To evaluate our experience with more than 500 minimally invasive hepatic procedures.Recent data have confirmed the safety and efficacy of minimally invasive liver surgery. Despite these reports, no programmatic approach to minimally invasive liver surgery has been proposed.We retrospectively reviewed all patients who underwent a minimally invasive procedure for the management of hepatic tumors between January 2001 and April 2008. Patients were divided into 3 groups: laparoscopy with intraoperative ultrasound and biopsy only, laparoscopic radiofrequency ablation (RFA), and minimally invasive resection. To compare the various forms of surgery, we analyzed the incidence of complications, tumor recurrence, mortality, and cost. Statistical analysis was performed using chi(2) analysis, Student t test, Kaplan-Meier survival analysis with the log-rank test, and multivariable Cox models.A total of 590 minimally invasive hepatic procedures were performed during 489 operative interventions. The representative tumor histologies were: hepatocellular carcinoma (HCC; N = 210), colorectal carcinoma (N = 40), miscellaneous liver metastases (N = 42), biliary cancer (N = 20), and benign tumors (N = 176). Thirty-five patients underwent laparoscopic ultrasound and confirmatory biopsy alone; 201 patients underwent 240 laparoscopic RFAs, and 253 patients underwent 306 minimally invasive resections. Conversion rates to open surgery for the RFA and resection group were 2% overall. One hundred ninety-nine (40.6%) patients were cirrhotic; 31 resections were performed in cirrhotic patients. Complication and mortality rates for RFA and resection were comparable (11% vs. 16%, and 1.5% vs. 1.6%). However, complication rates (14% vs. 29%; P = 0.02) and mortality (0.3% vs. 9.7%; P = 0.006) rates were higher in the cirrhotic versus noncirrhotic resection group. Overall recurrence rates for RFA and resection groups were 24% and 23%, respectively. Local recurrence rates were higher in the RFA group (6.3% versus 1.5%; P0.06). Overall patient survival differed between HCC patients receiving RFA alone and those receiving RFA and OLT (P0.0001). Overall survival for cancer patients receiving RFA versus resection differed significantly when unadjusted for other covariates (P = 0.01), and remained marginally significant in a multivariable model (P = 0.056).Minimally invasive hepatic surgery has become a viable alternative to open hepatic surgery. Our present data are equivalent or superior to those encountered in any large open series. Our experience with RFA confirms a low local recurrence rate and an excellent technique for bridging patients to transplantation. Morbidity and mortality rates for minimally invasive hepatic resections in cirrhotics, is similar to other reported open resection series. This series confirmed excellent interim survival rates after laparoscopic HR and superiority over RFA in the treatment of cancer, with significantly lower local tumor recurrence rate.

This work is a 1-yr interim analysis of a prospective, randomized, multicenter trial evaluating the effect of corticosteroid-free immunosuppression on hepatitis C virus–positive (HCV+) liver transplant recipients following liver transplantation (LT). Patients received tacrolimus and corticosteroids (Arm 1; n = 80); tacrolimus, corticosteroids, and mycophenolate mofetil (MMF) (Arm 2; n = 79); or daclizumab induction, tacrolimus, and MMF (Arm 3; n = 153). At 1 yr, 64.1%, 63.4%, and 69.4% of patients achieved the composite primary endpoint of freedom from rejection, freedom from HCV recurrence, and freedom from treatment failure, respectively. Excellent patient and graft survival did not differ significantly among treatment arms. Freedom from HCV recurrence at 1 yr was 61.8 ± 6.2%, 60.1 ± 6.1%, and 67.0 ± 4.3% in Arms 1, 2, and 3, respectively (P = not significant). Freedom from rejection was significantly higher in Arm 3 compared to Arm 1 (93.0 ± 2.2% vs. 81.9 ± 4.4%; P = 0.011). Multivariate analysis identified acute rejection (hazard ratio = 2.692; P = 0.001) and donor age (hazard ratio = 1.015; P = 0.001) as significant risk factors for HCV recurrence. HCV recurrence was not influenced by recipient demographics, HCV genotype, or immunosuppression. In conclusion, these results suggest that a corticosteroid-free regimen of tacrolimus and MMF following daclizumab induction is safe and effective in HCV+ liver transplant recipients. Liver Transpl 13:1521–1531, 2007. © 2007 AASLD.

Primary fascial closure is often difficult after adult orthotopic liver transplantation (OLT), complicated by donor-to-recipient graft size mismatch, post-reperfusion hepatic edema, coagulopathy, or intestinal edema. Attempts at closing the abdomen under these circumstances can cause increase in intra-abdominal pressures, resulting in significant complications, including graft loss. Temporary closure with silastic mesh has been used as a viable option in children receiving transplants, but there is no experience recorded with its use in adults. A retrospective review was conducted on 200 consecutive liver transplantations performed over 42 months (October 2002 to February 2006). Records were evaluated for patient and donor demographics, perioperative factors including Model for End-Stage Liver Disease and Child-Turcotte-Pugh scores, indications for OLT, ischemic times, blood product administration, and use of temporary silastic mesh closure. Patients requiring silastic mesh were further evaluated for indication, time to primary fascial closure, duration of intubation, length of stay, graft function, and complications (infectious, vascular, biliary, and hernia development). Comparisons were made with a cohort of patients undergoing OLT over the same time period but who were closed primarily, without the use of temporary silastic mesh. Fifty-one liver transplantations (25.5%) of the 200 total transplant cohort used silastic mesh closure. Comparison of the cohorts (primary closure vs. temporary mesh) revealed that no differences existed, except the requirement of all blood products was significantly greater in the silastic mesh group (P < 0.001). Bowel edema (47.1%) and coagulopathy (37.3%) were the most common indications for mesh closure, with less frequent reasons including donor to recipient size mismatch (11.8%), hemodynamic instability, and a large preexisting fascial defect (2.0% each). The average time from transplant to final fascial closure was 3.4 days (range 2-9 days). In the silastic cohort, 41 transplants where closed primarily, 3 required the addition of synthetic mesh, and 6 had component separation and flap closure. After fascial closure, the mean time to extubation was 1 day. The median length of follow-up was 1.3 years for the silastic closure group. Long-term wound complications in the silastic closure group included 1 instance of colonic fistula, 2 incisional hernias, and 2 wound infections. The 30-day and 1-year patient survival for this group were 93.6 and 82.4%, respectively, and the graft survival for those same periods were 90.2 and 77.7%, respectively. Wound complications, rates of hepatic artery thrombosis or stricture, portal vein thrombosis or stricture, biliary complications, and allograft and patient survival were no different than those in patients undergoing initial primary closure. In adult liver transplantation with a difficult (or potentially difficult) abdomen, temporary closure with silastic mesh was found to allow for uncomplicated fascial closure in a short period of time, with rapid extubation times, excellent graft function, and minimal instances of infectious or wound complications. In circumstances where large amounts of blood products are required, where a size mismatch exists, or where bowel edema is present during adult liver transplantation, temporary closure with silastic mesh is an ideal strategy.

Background. Haemodialysis vascular access dysfunction is currently a huge clinical problem. In an attempt to reduce the morbidity associated with haemodialysis vascular access dysfunction, we have previously developed and validated a local perivascular paclitaxel release system that has been shown to release paclitaxel for at least 3 weeks. The aim of the current study was to evaluate the in vivo use of these perivascular wraps (for both safety and efficacy) at different time points in our pig model of arteriovenous graft stenosis. Methods. Paclitaxel-loaded ethylene vinyl acetate wraps were placed around the graft-vein anastomosis on one side, with control polymers being placed on the contralateral side in our pig model of arteriovenous graft stenosis. Animals were sacrificed at early (10-11 days), middle (23-24 days) and late (32-38 days) time points. The entire graft-vein anastomosis was removed at the time of sacrifice and assessed for the extent of luminal stenosis using histomorphometric techniques. Result. Graft-vein anastomoses treated with the paclitaxel-loaded polymers had an almost complete absence of luminal stenosis at the middle (23-24 days) and late (32-38 days) time points (when one would expect the development of neointimal hyperplasia) as compared with the contralateral control graft-vein anastomoses (37.90% luminal stenosis in the controls vs 0.10% in the paclitaxel group). There were minimal local side effects from this procedure. Conclusions. Our results demonstrate the safety and efficacy of paclitaxel-loaded perivascular wraps in the setting of a pig model of arteriovenous graft stenosis. We believe that such a local approach which could be easily applied at the time of surgery is ideally suited for use in the clinical setting of haemodialysis vascular access dysfunction. It is likely that this novel approach could result in a significant reduction in the huge economic and health morbidity costs currently associated with this recalcitrant clinical problem.

Hepatocellular carcinoma (HCC) remains one of the most common malignancies in the world with an estimated 500,000 to 1 million new cases diagnosed each year. These primary cancers are associated most commonly with chronic liver disease or cirrhosis. In Western countries, the principle causes of chronic liver disease associated with HCC are chronic alcohol usage and hepatitis B and C infection. In the United States, there has been a substantial rise in the incidence of HCC, which is directly linked to the rising incidence of hepatitis C (HCV) infection. The median survival of patients with untreated HCC in the setting of cirrhosis is 6 to 9 months. The traditional management of HCC confined to the liver has been operative resection. Unfortunately, in the majority of patients with HCC their underlying liver disease precludes them from hepatic resection. Fewer than 15% of patients presenting with HCC are resectional candidates. Historically the most controversial management of HCC has been liver transplantation, which results in the most extensive resection, a complete hepatectomy. This treatment modality provides an oncologically sound approach with the complete removal of HCC that is confined within the liver. This approach also eliminates the cumbersome problem of secondary primaries. The total hepatectomy provides simultaneous treatment of the caus

The use of minimally invasive procedures has revolutionized modern surgery. Only recently has laparoscopy been introduced for use in hepatic surgery.Patient demographics, tumor characteristics, and outcomes were evaluated for all initial cases of laparoscopic hepatic resection.Twenty-one resections were performed in 17 patients; 5 were performed for malignancy, of which 3 had underlying cirrhosis, and the remaining 12 for benign symptomatic disease. Mean patient age was 55.4 (range, 24-82 years). The mean number of lesions was 1.4 (range, 1-5), having an average size of 7.6 cm (range, 2-30 cm). Mean operative time was 2.8 hours (range, 2-5 hours) hours. Most resections involved 1 or more Couinaud segments. Mean blood loss was 288 cc (range, 50-150 cc). Complications included re-operation for hemorrhage (n=2), biliary leakage (n=1), and death from hepatic failure (n=1). Mean length of stay was 2.9 days (range, 1-14). When compared with our series of 100 patients who underwent open hepatic resection for benign tumors, significantly greater means ( P.05) were noted for blood loss (485 cc), operative time (4.5 hours), and length of stay (6.5 days).Laparoscopic hepatic surgery, though complex, can be performed safely and efficaciously. Minimally invasive surgery appears to provide several distinct advantages over traditional open hepatic surgery. However, techniques for the laparoscopic control of bleeding and bile leak remain in their infancy.

Nitric oxide generation from porcine kidney slices is assessed using a new planar NO-selective amperometric sensor. The planar shape of the sensor allows for direct NO measurements near the surface (10 microm) of renal tissue slices in real time. Renal NO production may be modulated by the addition of L-arginine, arginine homopolymers (R2, R6, R10), and protamine, all of which can potentially transport across cellular membranes and provide a substrate for nitric oxide synthase within kidney parenchyma. Real-time amperometric measurements demonstrate that most L-arginine species can translocate across the cell membrane and rapidly increase NO production. However, no increase in NO generation is observed when the dimer of L-arginine (R2) is added to the solution bathing the tissue, suggesting that this species cannot permeate cell membranes. The degree of enhancement in NO generation observed for L-arginine and the larger peptides depends on the structure and follows the following sequence: R10 (decamer)protamineR6 (hexamer)L-arginine. Protamine and the R10 decamer, especially, induce the largest increases in NO generation owing to their apparent rapid translocation into cells and subsequent cleavage by proteases to create high intracellular levels of L-arginine. The effect of sensor size (for sensor dimensions of 0.15- and 1-mm outer diameters) on the measured surface NO levels is also examined. The larger sensor traps more NO but hinders access of the L-arginine species to the tissue area between the flat distal plane of the sensor and the surface of the kidney slice. The use of such NO-generating peptides may be important in numerous biological systems that depend on NO production, such as ischemia-reperfusion injury and thrombogenesis.