We studied the role of donor and recipient age in transplantation/ischemia-reperfusion injury (TIRI) and short- and long-term graft and patient survival. Eight hundred twenty-two patients underwent deceased donor liver transplantation, with 197 donors being > or = 60 years old. We evaluated markers of reperfusion injury, graft function, and clinical outcomes as well as short- and long-term graft and patient survival. Increased donor age was associated with more severe TIRI and decreased 3- and 5-year graft survival (73% versus 85% and 72% versus 81%, P < 0.001) and patient survival (77% versus 88% and 77% versus 82%, P < 0.003). Hepatitis C virus (HCV) infection and recipient age were the only independent risk factors for graft and patient survival in patients receiving an older graft. In the HCV(+) cohort (297 patients), patients > or = 50 years old who were transplanted with an older graft versus a younger graft had significantly decreased 3- and 5-year graft survival (68% versus 83% and 64% versus 83%, P < 0.009). In contrast, HCV(+) patients < 50 years old had similar 3- and 5-year graft survival if transplanted with either a young graft or an old graft (81% versus 82% and 81% versus 82%, P = 0.9). In conclusion, recipient age and HCV status affect the graft and patient survival of older livers. Combining older grafts with older recipients should be avoided, particularly in HCV(+) patients, whereas the effects of donor age can be minimized in younger recipients.
We explored the possibility that a simple and single test could replace the modified Mallampati score for either a difficult or an unaccomplished tracheal intubation in an impending hypoxic patient. Three hundred adult patients were enrolled in this study. They were subjected to the following assessments: 1) oropharyngeal class according to the modified Mallampati criteria; 2) the new, upper lip bite criteria—class I = lower incisors can bite the upper lip above the vermilion line, class II = lower incisors can bite the upper lip below the vermilion line, and class III = lower incisors cannot bite the upper lip; and 3) laryngeal view grading according to Cormack's criteria. The incidence of difficult intubation was 5.7%. The upper lip bite test showed significantly higher specificity and accuracy than the modified Mallampati test (P < 0.001). Comparisons of sensitivity, positive and negative predictive values, between the two tests, however, did not reveal any significant differences (P > 0.05). In conclusion, the upper lip bite test is an acceptable option for predicting difficult intubation as a simple, single test.
We explored the possibility that a simple and single test could replace the modified Mallampati score for either a difficult or an unaccomplished tracheal intubation in an impending hypoxic patient. Three hundred adult patients were enrolled in this study. They were subjected to the following assessments: 1) oropharyngeal class according to the modified Mallampati criteria; 2) the new, upper lip bite criteria—class I = lower incisors can bite the upper lip above the vermilion line, class II = lower incisors can bite the upper lip below the vermilion line, and class III = lower incisors cannot bite the upper lip; and 3) laryngeal view grading according to Cormack’s criteria. The incidence of difficult intubation was 5.7%. The upper lip bite test showed significantly higher specificity and accuracy than the modified Mallampati test (P < 0.001). Comparisons of sensitivity, positive and negative predictive values, between the two tests, however, did not reveal any significant differences (P > 0.05). In conclusion, the upper lip bite test is an acceptable option for predicting difficult intubation as a simple, single test.
Catecholamines are often administered during and after liver transplantation (LTx) to support systemic perfusion and to increase organ oxygen supply. Some vasoactive agents can compromise visceral organ perfusion. We followed the hypothesis that the vasculature of transplanted livers presents with a higher sensitivity, which leads to an increased vulnerability for flow derangement after application of epinephrine (Epi) or norepinephrine (NorEpi). Hepatic macroperfusion and microperfusion during systemic Epi or NorEpi infusion were measured by Doppler flow and thermodiffusion probes in porcine native, denervated, and transplanted livers (n = 16 in each group). Epi or NorEpi were infused (n = 8 in each subgroup) in predefined dosages (low dose = 5 μg/kg/minute and high dose = 10 μg/kg/minute) over 240 minutes. Systemic cardiocirculatory parameters were monitored continuously. Hepatic perfusion data were compared between all groups at comparable time points and dosages. In all native, denervated, and transplanted liver groups, Epi and NorEpi induced an inconsistent rise of mean arterial pressure and heart rate shortly after onset of infusion in both dosages compared with baseline. No significant differences of cardiovascular parameters at comparable time points were observed. In native livers, Epi and NorEpi induced only temporary alterations of hepatic macrocirculation and microcirculation, which returned to baseline 2 hours after onset of infusion. No significant alterations of hepatic blood flow were detected after isolated surgical denervation of the liver. By contrast, transplanted livers showed a progressive decline of hepatic macrocirculation (33–75% reduction) and microcirculation (39–58% reduction) during catecholamine infusions in a dose-dependent fashion. Characteristics of liver blood flow impairment were comparable for both vasoactive agents. In conclusion, pronounced disturbances of hepatic macrocirculation and microcirculation were observed during systemic Epi and NorEpi infusion after LTx compared with native and denervated livers. Microcirculation disturbances after LTx might be explained by impairment of hepatic blood flow regulation caused by an increased sensitivity of hepatic vasculature after ischemia-reperfusion and by lengthening of vasopressor effects caused by reduced hepatocyte metabolism. Clinicians should be aware of this potentially hazardous effect. Therefore, application of catecholamines after clinical LTx should be indicated carefully. (Liver Transpl 2005;11:174–187.)
Background: Microdialysis (MD) can detect organ-related metabolic changes before they become measurable in plasma through the biochemical parameters. This study aims to evaluate the early detection of metabolic changes during experimental kidney transplantation (KTx). Material and methods: During preparation of 8 donor kidneys, one MD catheter was inserted in the renal cortex and samples were collected. After a 6-hour cold ischemia time (CIT), kidneys were implanted in the 8 recipient pigs. Throughout the warm ischemia time (WIT) and after reperfusion, kidneys were monitored. The interstitial glucose, lactate, pyruvate, glutamate, and glycerol concentrations were evaluated. Results: A significant decline in glucose level was observed at the end of CIT. The lactate level was reduced to the minimum point of 0.35 ± 0.08 mmol/L in CIT. After reperfusion, lactate values raised significantly. During the WIT, the pyruvate level increased, continued until the end of the WIT. For glutamate, a steady increase was noted during explantation, CIT, WIT, and early reperfusion phases. The increase of glycerol value continued in the early postreperfusion, which was then followed by a sharp decline. Conclusion: MD is a fast and simple minimally invasive method for measurement of metabolic substrates in renal parenchyma during KTx. MD offers the option of detecting minor changes of interstitial glucose, lactate, pyruvate, glutamate, and glycerol in every stage of KTx. Through the use of MD, metabolic changes can be continuously monitored during the entire procedure of KTx.
Many centers require a minimal graft to body weight ratio (GBWR) >or= 0.8 as an arbitrary threshold to proceed with right-lobe living donor liver transplantation (RL-LDLT), and there is often hesitancy about transplanting lower volume living donor (LD) liver grafts into sicker patients. The data supporting this dogma, based on the early experience with RL-LDLT at Asian centers, are weak. To determine the effect of LD liver volume in the modern era, we investigated the impact of GBWR on the outcome of RL-LDLT with a GBWR as low as 0.6 at the University of Toronto. Between April 2000 and September 2008, 271 adult-to-adult RL-LDLT procedures and 614 deceased donor liver transplants were performed. Twenty-two living donor liver transplantation (LDLT) cases with a GBWR of 0.59 to 0.79 (group A) were compared with 249 LDLT cases with a GBWR >or= 0.8 (group B) and with 66 full-graft deceased donor liver transplants (group C), who were matched 3:1 according to donor and recipient age, Model for End-Stage Liver Disease score, and presence of hepatitis C and hepatocellular carcinoma with the low-GBWR group. Portal vein shunts were not used. Markers of reperfusion injury [aspartate aminotransferase (AST) and alanine aminotransferase (ALT)], graft function (international normalized ratio and bilirubin), complications graded by the Clavien score, and graft and patient survival were compared. As expected, LD recipients had a significantly shorter cold ischemia time (94 +/- 43 minutes for A, 96 +/- 57 minutes for B, and 453 +/- 152 minutes for C, P = 0.0001). However, the peak AST, peak ALT, absolute decrease in the international normalized ratio, day 7 bilirubin level, postoperative creatinine clearance, complication rate graded by the Clavien score, and median hospital stay were similar in all groups. The rate of biliary complications was higher with LD grafts than deceased donor grafts (19% for A versus 10% for B and 0% for C, P = 0.2). Patient survival was similar in all groups at 1, 3, and 5 years (91% for A versus 89% for B and 93% for C at 1 year, 87% for A versus 81% for B and 89% for C at 3 years, and 83% for A versus 81% for B and 87% for C at 5 years, P = 0.63). A Cox proportional regression analysis revealed only hepatitis C virus as a risk factor for poorer graft survival and not GBWR as a continuous or categorical variable. In conclusion, we found no evidence of inferior outcomes with smaller size grafts versus larger size LD grafts or full-size deceased donor grafts. Further studies are warranted to examine the factors affecting the function of smaller grafts for living liver donation and thereby define the safe lower limits for transplantation.
