Biomedical subjects

James V Guarrera

Publications and source records attributed to James V Guarrera.

5 recordsLinked to original sources

PubMed2006

Extended-donor criteria liver allografts.

Extended-donor criteria liver allografts do not meet traditional criteria for transplantation. Although these organs offer immediate expansion of the donor pool, transplantation of extended-donor criteria liver allografts increases potential short- and long-term risk to the recipient. This risk may manifest as impaired allograft function or donor-transmitted disease. Guidelines defining this category of donor, level of acceptable risk, principles of consent, and post-transplantation surveillance have not been defined. This article reviews the utilization, ethical considerations, and outcomes of extended-donor criteria liver allografts.

Donor Selection↗

PubMed2006

Blockade of the receptor for advanced glycation end products attenuates acetaminophen-induced hepatotoxicity in mice.

BACKGROUND AND AIM: Severe injury to the liver, such as that induced by toxic doses of acetaminophen, triggers a cascade of events leading to hepatocyte death. It is hypothesized that activation of the receptor for advanced glycation end products (RAGE) might contribute to acetaminophen-induced liver toxicity by virtue of its ability to generate reactive oxygen species, at least in part via nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and thereby activate downstream signaling pathways leading to cellular injury. METHODS: A model was employed in which toxic doses of acetaminophen (1125 mg/kg) were administered to C57BL/6 mice. To block RAGE, mice received murine soluble (s) RAGE, the extracellular ligand binding domain of the receptor that acts as a decoy to interrupt ligand-RAGE signaling. RESULTS: Animals treated with sRAGE displayed increased survival compared with vehicle treatment, and markedly decreased hepatic necrosis. Consistent with an important role for RAGE-triggered oxidant stress in acetaminophen-induced injury, a significant reduction of nitrotyrosine protein adducts was observed in hepatic tissue in sRAGE-treated versus vehicle-treated mice receiving acetaminophen, in parallel with significantly increased levels of glutathione. In addition, pro-regenerative cytokines tumor necrosis factor-alpha and interleukin-6 were increased in sRAGE-treated versus vehicle-treated mice. CONCLUSION: These findings implicate RAGE-dependent mechanisms in acetaminophen-induced liver damage and suggest that blockade of this pathway may impart beneficial effects in toxin-induced liver injury.

Acetaminophen↗

PubMed2004

Microvascular hepatic artery anastomosis in pediatric segmental liver transplantation: microscope vs loupe.

Use of operative microscopy (OM) has dramatically reduced the incidence of hepatic artery thrombosis (HAT) in children undergoing segmental liver transplantation. We used OM (12-16x) in our early experience. We changed to high power loupe magnification (6x) after 14 cases. We examined our experience with microvascular hepatic artery reconstruction in 28 consecutive children (< 18 years) who underwent living donor (LDLT) or split liver transplantation (SLT). Reconstructions were done with interrupted, end-to-end anastomoses with 8-0 polypropylene using microvascular techniques. Group 1 consisted of 14 children who underwent LDLT employing OM for the hepatic artery anastomosis. Group 2 consisted of the subsequent 14 children (11 LDLT, 3 SLT) in whom 6x loupe optics were used for the arterial anastomosis. Grafts included 25 left lateral segments, 2 left lobes, and 1 right lobe. Recipients' median age was 1.0 years (range 3 months to 17 years). The mean follow-up time was 27.1 months. There were no cases of HAT. Variables of age, sex, graft type, number of Doppler ultrasound exams (DUS), and biliary complications were similar between groups. Microvascular hepatic artery reconstruction in children with 6x loupe magnification can yield results as good as operative microscopy.

Adolescent↗

PubMed2004

Pulsatile machine perfusion with Vasosol solution improves early graft function after cadaveric renal transplantation.

BACKGROUND: Cold storage is the most common method of preservation in renal transplantation, but pulsatile machine perfusion (MP) is increasingly used for purposes of ex vivo assessment and resuscitation of high risk allografts. Vasosol (VSL) MP solution (MPS) (Pike Laboratories Inc, Eagle, PA) is a novel perfusate with enhanced vasodilatory and antioxidant capacity. We report our experience with VSL in machine preservation of renal allografts. METHODS: Locally procured cadaver kidney pairs undergoing MP were randomized to VSL or control solution (Belzer MPS; Trans-Med, Elk River, MN). En bloc perfusion was performed according to standard MP procedures. Transplantation was performed at 1 of 12 local transplant centers. Donor and recipient data were collected prospectively. RESULTS: Data from 162 transplanted kidneys were analyzed. A total of 82 renal grafts were perfused with VSL, and 80 were perfused with control solution. No organs were lost secondary to the technique of MP. There was no difference in donor or recipient age between groups. Kidneys perfused with VSL exhibited significantly higher rates of immediate function and significantly less delayed graft function (12.2% vs. 21.2%). Discharge creatinine and length of stay were also significantly improved in the VSL group. One-year graft and patient survivals were equivalent (95%) in both groups. CONCLUSIONS: VSL improved early graft function and shortened the length of stay compared with Belzer MPS. Further improvement in preservation solutions in conjunction with pulsatile perfusion shows promise in improving early outcomes after renal transplantation, especially for extended criteria donor kidneys.

Adenosine↗

PubMed2003

Outflow reconstruction in right hepatic live donor liver transplantation.

BACKGROUND: Inconstant venous anatomy increases the risk of outflow complications in right hepatic live donor liver transplantation (RH-LDT), but no consensus has emerged guiding optimal reconstruction for venous outflow. METHODS: We retrospectively analyzed surgical venous reconstruction using a flexible approach to anterior accessory veins in 48 RH-LDTs performed between April, 1998 and July, 2002. RESULTS: Actuarial recipient graft and patient survival was 79% and 85%, respectively. Single hepatic venous anastomosis was performed in 74% of the patients. Twelve patients underwent reconstruction of 20 accessory veins, including 7 posterior segment veins and 13 anterior segment veins. Anterior vein reconstruction techniques included end-to-end anastomosis to the middle hepatic vein, interposition conduit, venoplasty, or a combination of techniques. Documented complications related to the venous anastomosis occurred in only 1 patient (2%), with no patient having a documented venous thrombosis of either the main RHV or a reconstructed accessory vein. There were no differences in outcome based on single versus multiple venous reconstruction. Anteromedial congestion was noted in 3 patients in the absence of anatomic venous anastomotic complication, but the clinical significance of this finding is unclear. CONCLUSIONS: Despite variations in segmental venous drainage and a propensity for anteromedial congestion in right hepatic grafts, RH-LDT can be performed without outflow obstruction with close attention to a wide RHV anastomosis. In addition, anterior accessory vein reconstruction can be reserved for grafts of marginal size or quality where early postoperative venous congestion may impair early graft function. Routine extended hepatectomy incorporating the MHV with the graft is unnecessary.

Actuarial Analysis↗