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Biomedical subjects

A W Avolio

Publications and source records attributed to A W Avolio.

At least 19 recordsLinked to original sources
PubMed2006

The nonstandard liver, a hidden resource that cannot be overlooked: implications for the identification of the best recipient.

We described the characteristics of livers already labeled as marginal, nonstandard, or selected with extended criteria: donors of elderly age, steatosis, hemodynamic instability, long cold ischemia time, high serum Na, HbcAb-positive status, HCVAb-positive status. Recipients characteristics (gender, UNOS status, MELD score, indication for transplantation) and their best possible match to nonstandard donors were evaluated with a report of the recent guidelines and the specific algorithms to optimize recipient identification.

Algorithms↗
PubMed2006

Use of "O" blood group liver donors for nonidentical recipients: does this represent a double penalty for "O" blood group candidates?

Candidates for liver transplantation with AB blood group remain on the waiting list for shorter times than candidates with O blood group. To investigate the reasons of this phenomenon, we analyzed data concerning deceased donors, liver transplant candidates, and liver first transplants performed in the United States during the period 2003 to 2004. The percentage of deceased donors with blood group O was higher than that of candidates on the waiting list with the identical blood group (P < .05). On the other hand, for blood groups A, B, and AB an opposite situation was observed: the percentages of deceased donors were significantly lower compared to those candidates with the identical blood group (A blood group, P < .05; B and AB blood groups, P < .001). When the number of grafts from deceased donors was compared with the number of those effectively transplanted, a negative difference for O blood group recipients was found (ie, transplanted livers < harvested livers) and a positive one for AB blood group (transplanted livers > harvested livers) were found. Since disease progression and causes of acute liver failure, including primary nonfunction and hepatic artery thrombosis leading to retransplantation were similar among the various blood groups, we concluded that the shorter waiting time for AB patients in the pre-MELD era was due to the use of compatible livers to the detriment of group O recipients.

ABO Blood-Group System↗
PubMed2006

Prognostic value of MELD score and donor quality in liver transplantation: implications for the donor recipient match.

The model for End-stage Liver Disease (MELD) has been adopted by the Organ Procurement and Transplantation Network (OPTN) in 2002 as the standard priority rule for the liver transplantation waiting list. We retrospectively calculated the pretransplant MELD scores of 226 consecutive adult grafts. We did not correct for hepatocellular carcinoma comorbidity or for the etiology of liver disease. Cases were categorized according to the MELD score: class I, MELD scores between 6 and 14 (low MELD, n = 116); class II, MELD score between 15 and 24 (intermediate MELD, n = 78); class III, MELD score between 25 and 42 (high MELD, n = 32). All patients were transplanted using deceased donors. Grafts were categorized also according to donor quality (standard donor vs nonstandard donor). Sorting into categories was performed before transplant by officers of the Central-South Italian Transplant Organization overregional organ procurement agencies, namely OCST. Differences in Kaplan-Meier graft survivals (GS) between low MELD class and high MELD class were statistically significant (P < .01). Among standard donors, the 6-month GS were 83%, 94%, and 63% for the low, intermediate, and high MELD subset, respectively, differences that did not reach statistical significance. Among nonstandard donors, the 6-month GS were 77%, 71%, and 38% for the low, intermediate, and high MELD classes, respectively. Differences between low MELD class and intermediate MELD class and between low MELD class and high MELD class were statistically significant (P < .01). We strongly suggest that the utilization of nonstandard organs should be avoided for patients with high MELD scores.

Follow-Up Studies↗
PubMed2006

Comparative evaluation of two perfusion solutions for liver preservation and transplantation.

The University of Wisconsin solution (UW) and the Bretschneider solution (HTK) were used in 39 adult cadaveric donors: 22 perfused with UW (group 1) and 17 with HTK (group II). Donors were flushed through the aorta (UW, 5 to 6 L; HTK, 8 to 10 L) and through the portal vein (UW or HTK, 1 L). Grafts perfused with HTK showed lower levels of SGOT at postoperative day 7 than those transplanted with UW (38 +/- 19 vs 58 +/- 31, P < .05). No difference was observed in other functional and outcome parameters. No cases of primary dysfunction were observed. Six-month graft survival was 85.7% in HTK group and 80.9% in UW group (P = NS). Six unrelated deaths were observed. Five biliary complications were observed in five patients: three in the UW group and two in the HTK group. In conclusion, data fail to show major differences between the two solutions used.

Adult↗
PubMed2006

Molecular adsorbent recirculating system in liver transplantation: Safety and efficacy.

We assessed the safety and clinical efficacy of the Molecular Adsorbent Recirculating System (MARS) in liver failure patients admitted to our intensive care unit (ICU) from May 2000 to February 2006. Of 28 adult patients with bilirubin >15 mg/dL and hepatic encephalopathy (HE) grade > or =2 or hepato-renal syndrome, 22 patients were included in the study, because 6 patients were older than 65 years of age or showed recent alcohol abuse or extrahepatic malignancy. Patients were assigned to 2 groups according to whether MARS therapy was associated with a transplantation procedure: 11 patients received MARS therapy and liver transplantation (OLT group) and 11 patients received MARS therapy alone (non-OLT group). Five of 11 patients in the OLT group were listed for transplantation and 6 patients with graft failure for retransplantation. The patients in the OLT and non-OLT groups were similar in MELD, SOFA, and SAPS scores. All patients were stable and free from complications. MARS significantly reduced bilirubin, bile acids, and blood urea nitrogen (BUN) levels in both groups (P < .05), whereas a significant decrease in ammonia level was observed in the OLT group. Patient survival rates at 3 and 6 months in the OLT group were 91% and 73%, respectively, and in the non-OLT group, 9% and 9%, respectively (P < .001). MARS was safe and well tolerated, improving biochemical parameters, neurological function, and pruritus. In terms of survival, the use of MARS alone was not effective due to the high rate of multiple organ failure. Nevertheless, the association of MARS with a transplant/retransplantation procedure was highly effective.

Adult↗
PubMed2006

Allocation of nonstandard livers to transplant candidates with high MELD scores: Should this practice be continued?

MELD and PELD scores of 255 consecutive grafts were calculated (236 adult cases and 19 pediatric cases). No correction for the etiology of liver disease was performed. Retransplants were excluded. Three categories of patients were identified: low MELD (scores <12, n = 61); intermediate MELD (scores between 12-24, n = 159); high MELD (scores > or =25, n = 35). Grafts were categorized according to donor quality: standard livers (n = 199), vs nonstandard livers (n = 56). Nonstandard livers were identified by age > or =60, or at least by two of the following conditions: severe hemodynamic instability, ultrasound evidence of steatosis, natriemia > or =155 mEq/L, ICU stay >7 days, liver trauma, protracted anoxia as cause of brain death, transaminases levels x 4. In standard livers, the 12-month graft survival (GS) for low, intermediate, and high MELD classes were 88%, 74%, and 77%, respectively. In nonstandard livers, the 12-month GS for the low, intermediate, and high MELD classes were 84%, 55%, and 44%, respectively; differences between low MELD class and both intermediate and high MELD classes were significant (P < .05). Cox regression analysis of all cases identified the following parameters as independent predictors of GS: donor status; donor age; and recipient creatinine. The highest correlation with GS was found using donor age and recipient creatinine as covariates. In standard livers no variable was able to predict GS. In nonstandard livers the MELD-PELD score was the unique variable able to predict GS. We suggest avoiding the use of nonstandard livers for patients with high MELD scores.

Adolescent↗
PubMed2004

Prediction of 6-month survival after liver transplantation using Cox regression.

BACKGROUND: The outcome of liver transplantation (LTx) has been correlated with several donor and recipient factors. METHODS: A database of 191 consecutive LTx cases was analyzed using Kaplan-Meier and Cox regression statistics based on 80 variables. To avoid additional effects of late events on patient survival, the chosen endpoint was 6 months. Data were evaluated using SPSS statistical software. RESULTS: Kaplan-Meier analysis revealed a difference in 1- to 6-month graft survival between patients transplanted with organs from donors older versus younger than 60 years (Breslow, P <.01). Differences in 1- to 6-month graft survivals were observed between patients listed as UNOS status 3, 2B, 2A, and 1: the outcomes for UNOS status 2B versus UNOS status 2A and UNOS status 2B versus status 1 were significant (P <.05). Differences in 1- to 6-month graft survival rates were found between patients with versus without sepsis (P <.05), and with versus without rejection episodes (P <.01). Cox regression analysis revealed only three of the variables to be independent prognostic predictors of graft failure: donor age; postoperative septic status; and rejection. The best mathematical multivariate Cox regression model linked donor age + donor Na + rejection + sepsis to 1- to 6-month graft survival (chi-square = 29.06, P <.001). CONCLUSION: Factors predictive of 1- to 6-month graft survival after liver transplantation include donor age; UNOS status; sepsis; and rejection.

Age Factors↗
PubMed1999

Doppler ultrasonographic evaluation of the early changes in renal resistive index in cirrhotic patients undergoing liver transplantation.

Renal vasoconstriction commonly occurs in decompensated liver cirrhosis and is entirely reversible after hepatic transplantation. In this study we evaluated by Doppler ultrasonography the changes of renal vascular resistance occurring during the first month after transplantation. In 16 cirrhotic patients the intrarenal resistive index at the level of interlobar arteries and the blood urea nitrogen and serum creatinine levels were measured before (range, 1 to 34 days) and after transplantation (days 1, 3, 7, 14, 30). Before transplantation the median resistive index value was 0.69 (95% CI, 0.65 to 0.71) and eight of 16 patients showed abnormal values (0.70 or more). After transplantation, the median resistive index was significantly decreased on all the evaluation days, and no patient had abnormal values on posttransplantation day 7. No significant correlation was found between resistive index and serum creatinine or blood urea nitrogen levels. Doppler ultrasonography is a simple tool to evaluate the recovery of normal intrarenal arterial resistance levels after liver transplantation. One week appears to be the optimal timing to evaluate the renal resistive index in the posttransplantation period.

Adult↗
PubMed1998

Preoperative recipient data and immunosuppression levels are predictive of early patient survival after liver transplantation.

The role of donor, preoperative, intraoperative, and postoperative factors in predicting patient survival after liver transplantation was evaluated by the Bio Medicus data package on a database containing 162 variables filled with records from 100 consecutive first-liver transplant cases. Donor data did not predict outcome. Recipient preoperative data (Child status, HCV status) were predictive using life table and Cox regression methods. Recipient intraoperative data (by-pass time, warm ischemia time, delay in arterial revascularization, and packed red blood cell requirements) were predictive of outcome using life table analysis. Recipient post-operative data (rejection, sepsis, primary dysfunction, and hepatic artery thrombosis) were predictive of outcome.

Adult↗
PubMed1996

Marginal donors for patients on regular waiting lists for liver transplantation.

The use of marginal donors is well accepted by most centers for emergency situations, but there is debate on their use for patients on regular waiting lists. We report our experience of the 1-year survival for patients on waiting lists (n = 147, 1-year survival = 32%), patients transplanted from good donors (n = 60, 1-year survival = 84%), and patients transplanted from marginal donors (n = 15, 1-year survival = 56%). We concluded that liver transplantation from marginal donors (a) is a safe procedure (b) has a 1-year survival that is significantly better than that on a waiting list (c) is ethically justified especially in countries with donor shortages, and (d) may allow transplantation of "special" high risk and poor long-term outcome patients.

Graft Survival↗
PubMed1994

Pulmonary gas exchange during orthotopic liver transplantation.

The aim of this study was to evaluate the efficiency of pulmonary gas exchange during the course of liver transplantation. We studied 25 adult cirrhotic patients undergoing transplantation, performed with venovenous bypass. A significant increase in PaO2, and a significant decrease in physiological shunt and alveolar-arterial partial pressure difference were observed just before the start of venovenous bypass. These changes were probably caused by modifications in respiratory mechanics, such as an increase in functional residual capacity. There were no other respiratory changes during the anhepatic and post-anhepatic phases.

Adolescent↗