Perioperative Intra- and Extravascular Volume in Liver Transplant Recipients

Association between indocyanine green clearance test and ischemic type biliary lesions within one year after orthotopic liver transplantation

BACKGROUND

Ischemic type biliary lesions (ITBLs), a particular subset of non-anastomotic biliary strictures (NAS), are characterized by intra and extrahepatic strictures that occur in the absence of either hepatic artery thrombosis or stenosis. When they occur within the first year after liver transplantation their development is mostly related to ischemia-reperfusion injury (IRI). The indocyanine green plasma disappearance rate (ICG-PDR) might be able to predict the probability of IRI-induced graft damage after liver transplantation.

OBJECTIVE

Our aim was to evaluate the association between ICG-PDR and the occurrence of ITBLs. Secondly, we searched for evidence of IRI in patients presenting ITBLs.

METHODS

This retrospective single-center observational study assessed a cohort of 60 liver transplant patients. Each patient underwent ICG-PDR on the 1st postoperative day. ITBLs were identified by means of either cholangiography or magnetic resonance imaging evidence of a deformity and narrowing of the biliary tree in the absence of hepatic artery thrombosis/stenosis.

RESULTS

ITBLs were discovered in 10 patients out of 60 liver recipients (16.67%) within one year after transplantation. A low ICG-PDR value was found to be a significant predictive factor for ITBL development, with an OR of 0.87 and a 95% CI of 0.77-0.97. Liver biopsies were performed in 56 patients presenting unexplained abnormal liver function test results. A statistically significant association was found between the development of ITBLs and anatomopathological evidence of IRI.

LIMITATIONS

Retrospective, single-center study.

CONCLUSIONS

The findings from this study show a relationship between low ICG-PDR values on first post-operative-day and the occurrence of ITBLs within 1 year after transplantation.

Caspase-3-related apoptosis prevents pathological regeneration in a living liver donor rat model

PURPOSE

The main goal of this study was to determine the relationship of cleaved-caspase-3 (C3)-related apoptosis and hepatic proliferation, during the liver repopulation in a living liver donor rat model.

MATERIAL/METHODS

Thirty-three animals were randomized into eleven groups and evaluated on postoperative from 3 ​h until 384 ​h after 30%-partial hepatectomy (30%-PHx). Liver sections (5 ​μm) were processed by hematoxylin-eosin, and immunostaining for C3, accompanied by hepatic function test. C3 content and the hepatic lobule enlargement were analyzed by optical density, followed by cell counting.

RESULTS

Transient variations of alanine transferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were found. Significant increase in the C3 levels, and cell nuclei number, were detected at 12 ​h and 48 ​h after 30%-PHx, evidencing a correlation of p ​= ​-0.3679.

CONCLUSION

In the 30%-PHx rat model, C3-related apoptosis prevents proliferative pathological conditions during the hepatic lobule re-modeling.

Indocyanine green dye clearance test: early graft (dys)-function and long-term mortality after liver transplant. Should we continue to use it? An observational study

Early allograft dysfunction (EAD) can be a serious complication in the immediate postoperative period following liver transplantation. Our aim was to study the prognostic role of the indocyanine green plasma disappearance rate (ICG-PDR) in predicting early and late EAD and mortality at 3 and 12 months and 5 years after liver transplantation. ICG-PDR values were also assessed for association with the Donor Risk Index (DRI). 220 patients underwent orthotopic liver transplantation. In 77 patients, ICG-PDR was assessed on the 1st post-operative (PO) day. ICG, a water-soluble dye almost entirely excreted into the bile, was measured by spectrophotometry to evaluate graft (dys)-function. DRI was calculated in all patients. The primary study outcomes were the presence (or absence) of EAD after transplant and the results of mortality risk factor analysis. EAD occurred in 18 patients. 1st PO day ICG-PDR was significantly associated with EAD (p < 0.005). A threshold ICG-PDR value < 16%/min on the 1st PO day was also associated with patient probability to survive at 3 and 12 months and 5 years. The sensitivity and specificity of the AUC was good in predicting EAD, being 83% and 56%, respectively, for a 1st PO day ICG-PDR cut-off value < 16%/min. In this study, ICG-PDR on the 1st PO day following OLT can reliably predict EAD and survival at 3 and 12 months and 5 years. ICG-PDR should, therefore, be routinely performed on the 1st PO day following OLTx in all patients in light of its important prognostic role.

Effects of liver ischemia-reperfusion injury on respiratory mechanics and driving pressure during orthotopic liver transplantation

BACKGROUND

During orthotopic liver transplantation (OLT), liver graft ischemia-reperfusion injury (IRI) triggers a cytokine-mediated systemic inflammatory response, which impairs graft function and disrupts distal organ homeostasis. The objective of this prospective, observational trial was to assess the effects of IRI on lung and chest wall mechanics in the intraoperative period of patients undergoing OLT.

METHODS

In 26 patients undergoing OLT, we measured elastance of the respiratory system (ERS), partitioned into lung (EL) and chest wall (ECW), hemodynamics, and fluid and blood product intake before laparotomy (T1), after portal/caval surgical clamp (T2), and immediately (T3) and, at 90 and 180 minutes post-reperfusion (T4 and T5, respectively). Interleukin-6 (IL-6), monocyte chemotactic protein-1 (MCP-1), IL-1β and tumor necrosis factor-α plasma concentrations were assessed at T1, T4 and T5.

RESULTS

EL significantly decreased from T1 to T2 (13.5±4.4 vs 9.7±4.8 cmH2O/L, P<0.05), remained stable at T3, while at T4 (12.3±4.4 cmH2O/L, P<0.05) was well above levels recorded at T2, reaching its highest value at T5 (15±3.9 cmH2O/L, P<0.05). Variations in ERS, EL, driving pressure (∆P) and trans-pulmonary pressure (∆PL) significantly correlated with changes in IL-6 and MCP-1 plasma concentrations, but not with changes in wedge pressure, fluid amounts, and red blood cells and platelets administered. No correlation was found between changes in cytokine concentrations and ECW.

CONCLUSIONS

We found that EL, ECW, ∆P and ∆PL underwent significant variations during the OLT procedure. Further, we documented a significant association between the respiratory mechanics changes and the inflammatory response following liver graft reperfusion.

Evaluation of New Calibrated Pulse-Wave Analysis (VolumeViewTM/EV1000TM) for Cardiac Output Monitoring Undergoing Living Donor Liver Transplantation

Background

Intrapulmonary thermodilution technique using a pulmonary artery catheter is widely used for measuring cardiac output (CO) in patients undergoing liver transplantation. However, its invasiveness and associated complications have led to an interest in less invasive modalities. Thus, we aimed to evaluate whether the new calibrated pulse-wave analysis method monitoring (VolumeView^TM/EV1000^TM) is interchangeable with intrapulmonary thermodilution technique.

Methods

Twenty-eight patients undergoing living donor liver transplantation were enrolled in this prospective observational study. COs were recorded automatically by the two devices and compared simultaneously at 10-minute intervals. The agreement of absolute CO values and the tracking ability of CO changes trends were compared. A Bland-Altman analysis with percentage errors and concordance rate for trend analysis using both a 4-quadrant plot and a polar plot were performed on the data.

Results

A total of 375 paired datasets from 25 patients were included in analysis. COs measured by intrapulmonary thermodilution ranged from 3.8–13.7 L/min. The mean CO difference between the two techniques was 0.57 L/min, and the 95% limits of agreement were -0.98 L/min to 2.12 L/min with a percentage error of 42.3%. The percentage errors in the dissection, anhepatic, and reperfusion phase were 30.5%, 31.7%, and 27.4%, respectively. The concordance rate between the two techniques was 78.4%.

Conclusion

The calibrated pulse-wave analysis and intrapulmonary thermodilution failed to show acceptable interchangeability in terms of both estimating CO and tracking CO changes during living donor liver transplantation.

Evaluation of pleth variability index as a predictor of fluid responsiveness during orthotopic liver transplantation

Fluid management is challenging and still remains controversial in orthotopic liver transplantation (OLT). The pleth variability index (PVI) has been shown to be a reliable predictor of fluid responsiveness of perioperative and critically ill patients; however, it has not been evaluated in OLT. This study was designed to examine whether the PVI can reliably predict fluid responsiveness in OLT and to compare PVI with other hemodynamic indexes that are measured using the PiCCO2 monitoring system. Twenty-five patients were enrolled in this study. Each patient was monitored using the noninvasive Masimo and PiCCO2 monitoring system. PVI was obtained with a Masimo pulse oximeter. Cardiac index was obtained using a transpulmonary thermodilution technique (CITPTD). Stroke volume variation (SVV), pulse pressure variation, and systemic vascular resistance index were measured using the PiCCO2 system. Fluid loading (10 mL/kg colloid) was performed at two different phases during the operation, and fluid responsiveness was defined as an increase in CITPTD ≥ 15%. During the dissection phase and the anhepatic phase, respectively, 14 patients (56%) and 18 patients (75%) were classified as responders. There were no differences between the baseline values of the PVI of responders and nonresponders. Area under the curve for PVI was 0.56 (sensitivity 35%, specificity 90%, p = 0.58) at dissection phase, and was 0.55 (sensitivity 55%, specificity 66%, p = 0.58) at anhepatic phase. Of the parameters, a higher area under the curve value was found for SVV. We conclude that PVI was unable to predict fluid responsiveness with sufficient accuracy in patients undergoing OLT, but the SVV parameter was reliable.

Impact of a goal-directed therapy protocol on postoperative fluid balance in patients undergoing liver transplantation: a retrospective study

OBJECTIVE

Liver transplantation carries major risks during the perioperative period. Few studies focused on the hemodynamics of patients undergoing liver transplantation. The present study was aimed to evaluate the impact of the implementation of a protocol including goal-directed therapy in patients undergoing liver transplantation. Our first goal was to determine its impact on the fluid balance. Secondarily, we evaluated possible improvements in the patient outcomes.

STUDY DESIGN

A before and after study.

PATIENTS AND METHODS

Fifty patients undergoing liver transplantation were included during two successive six-month periods. During the first period, the management of the patients was left at the discretion of the senior physicians (control group, n=25). During the second period, the patients were treated according to a predetermined protocol including a specific hemodynamic monitoring (protocol group, n=25).

RESULTS

The fluid balance was negative in the protocol group and positive in the control group at 24h (-606mL vs. +3445mL, P<0.01) and 48h (-2315mL vs. +1170mL, P<0.01) after liver transplantation. The volume of the crystalloid administration was lower in the protocol group than in the control group (5000mL vs. 8000mL, P<0.01, and 1500mL vs. 6000mL, P<0.01, during surgery and 48h after liver transplantation, respectively). The duration of mechanical ventilation and postoperative ileus were significantly reduced in the protocol group, as compared with the control group, 20h vs. 94h (P<0.01) and 4days vs. 6days (P<0.01), respectively.

CONCLUSION

For patients undergoing liver transplantation, the implementation of a protocol aiming to optimize hemodynamics was associated with reduced fluid balance and decreased requirement for mechanical ventilation and postoperative ileus duration.