Regional anesthesia for transplantation surgery - A White Paper Part 2: Abdominal transplantation surgery.

Transplantation surgery continues to evolve and improve through advancements in transplant technique and technology. With the increased availability of ultrasound machines as well as the continued development of Enhanced Recovery after Surgery (ERAS) protocols, regional anesthesia has become an essential component of providing analgesia and minimizing opioid use perioperatively. Many centers currently utilize peripheral and neuraxial blocks during transplantation surgery, but these techniques are far from standardized practices. The utilization of these procedures is often dependent on transplantation centers' historical methods and perioperative cultures. To date, no formal guidelines or recommendations exist which address the use of regional anesthesia in transplantation surgery. In response, the Society for the Advancement of Transplant Anesthesia (SATA) identified experts in both transplantation surgery and regional anesthesia to review available literature concerning these topics. The goal of this task force was to provide an overview of these publications to help guide transplantation anesthesiologists in utilizing regional anesthesia. The literature search encompassed most transplantation surgeries currently performed and the multitude of associated regional anesthetic techniques. Outcomes analyzed included analgesic effectiveness of the blocks, reduction in other analgesic modalities-particularly opioid use, improvement in patient hemodynamics, as well as associated complications. The findings summarized in this systemic review support the use of regional anesthesia for postoperative pain control after transplantation surgeries. Part 1 of the manuscript focused on regional anesthesia performed in thoracic transplantation surgeries, and part 2 in abdominal transplantations. Specifically, regional anesthesia in liver, kidney, pancreas, intestinal, and uterus transplants or applicable surgeries are discussed.

Regional anesthesia for transplantation surgery - A white paper part 1: Thoracic transplantation surgery.

Transplantation surgery continues to evolve and improve through advancements in transplant technique and technology. With the increased availability of ultrasound machines as well as the continued development of enhanced recovery after surgery (ERAS) protocols, regional anesthesia has become an essential component of providing analgesia and minimizing opioid use perioperatively. Many centers currently utilize peripheral and neuraxial blocks during transplantation surgery, but these techniques are far from standardized practices. The utilization of these procedures is often dependent on transplantation centers' historical methods and perioperative cultures. To date, no formal guidelines or recommendations exist which address the use of regional anesthesia in transplantation surgery. In response, the Society for the Advancement of Transplant Anesthesia (SATA) identified experts in both transplantation surgery and regional anesthesia to review available literature concerning these topics. The goal of this task force was to provide an overview of these publications to help guide transplantation anesthesiologists in utilizing regional anesthesia. The literature search encompassed most transplantation surgeries currently performed and the multitude of associated regional anesthetic techniques. Outcomes analyzed included analgesic effectiveness of the blocks, reduction in other analgesic modalities-particularly opioid use, improvement in patient hemodynamics, as well as associated complications. The findings summarized in this systemic review support the use of regional anesthesia for postoperative pain control after transplantation surgeries. Part 1 of the manuscript focuses on regional anesthesia performed in thoracic transplantation surgeries, and part 2 in abdominal transplantations.

Intraoperative Cardiac Arrest During Adult Liver Transplantation: Incidence and Risk Factor Analysis From 7 Academic Centers in the United States.

BACKGROUND: Intraoperative cardiac arrest (ICA) has a reported frequency of 1 in 10,000 anesthetics but has a much higher estimated incidence in orthotopic liver transplantation (OLT). Single-center studies of ICA in OLT are limited by small sample size that prohibits multivariable regression analysis of risks. METHODS: Utilizing data from 7 academic medical centers, we performed a retrospective, observational study of 5296 adult liver transplant recipients (18-80 years old) between 2000 and 2017 to identify the rate of ICA, associated risk factors, and outcomes. RESULTS: ICA occurred in 196 cases (3.7% 95% confidence interval [CI], 3.2-4.2) and mortality occurred in 62 patients (1.2%). The intraoperative mortality rate was 31.6% in patients who experienced ICA. In a multivariable generalized linear mixed model, ICA was associated with body mass index (BMI) <20 (odds ratio [OR]: 2.04, 95% CI, 1.05-3.98; P = .0386), BMI ≥40 (2.16 [1.12-4.19]; P = .022), Model for End-Stage Liver Disease (MELD) score: (MELD 30-39: 1.75 [1.09-2.79], P = .02; MELD ≥40: 2.73 [1.53-4.85], P = .001), postreperfusion syndrome (PRS) (3.83 [2.75-5.34], P < .001), living donors (2.13 [1.16-3.89], P = .014), and reoperation (1.87 [1.13-3.11], P = .015). Overall 30-day and 1-year mortality were 4.18% and 11.0%, respectively. After ICA, 30-day and 1-year mortality were 43.9% and 52%, respectively, compared to 2.6% and 9.3% without ICA. CONCLUSIONS: We established a 3.7% incidence of ICA and a 1.2% incidence of intraoperative mortality in liver transplantation and confirmed previously identified risk factors for ICA including BMI, MELD score, PRS, and reoperation and identified new risk factors including living donor and length of surgery in this multicenter retrospective cohort. ICA, while rare, is associated with high intraoperative mortality, and future research must focus on therapy to reduce the incidence of ICA.

Perioperative Opioid Use and Chronic Post-Surgical Pain after Liver Transplantation: A Single Center Observational Study.

OBJECTIVES: To investigate the opioid requirements and prevalence of chronic postsurgical pain (CPSP) in liver transplant (LT) recipients and to evaluate the association of opioid use with postoperative survival. DESIGN: Retrospective analysis. SETTING: A large academic medical center. PATIENTS: Cadaveric liver transplants recipients from 2008 to 2016. INTERVENTIONS: Analysis of demographic, perioperative, and outcome data. MEASUREMENTS AND MAIN RESULTS: This study measured the incidence and quantity of preoperative opioid use, postoperative opioid requirements, the incidence of CPSP, and survival in patients with and without CPSP. Opioid requirements were calculated in morphine milligram equivalents. In total, 322 LT recipients satisfied the inclusion criteria. The cohort of interest included 61 patients (18.9%) who were prescribed opioids before LT, compared to the control group of 261. Postoperative opioid requirements were significantly higher in the cohort of interest in the first 24 hours (205.9 ± 318.5 v 60.4 ± 33.6 mg, p < 0.0001) and at 7 days after transplant (57.0 ± 70.6 mg v 19.2 ± 15.4 mg, p < 0.0001). Incidence of CPSP was significantly higher in the cohort of interest at 3 months (70.5% v 45.5%, p < 0.0001), at 2 years (38% v 12%), and at 5 years (29.8% v 6.9%) postoperatively. CPSP was a significant risk factor for patient mortality after transplantation (p = 0.038, HR 1.26). CONCLUSIONS: Opioid use is relatively frequent in patients waiting for LT. It significantly affects the postoperative opioid requirements and the incidence of CSPS. CPSP may significantly affect survival after LT.

Inferior Vena Cava Tumor Thrombus Dynamics and Perioperative Pulmonary Embolism: A Single-Center Experience.

OBJECTIVES: To analyze preoperative tumor thrombus progression and occurrence of perioperative pulmonary embolism (PE) in patients with inferior vena cava tumor thrombus resection. DESIGN: Retrospective analysis. SETTINGS: University of Washington Medical Center. PARTICIPANTS: Patients who had undergone inferior vena cava tumor resection with thrombectomy from 2014 to 2017. INTERVENTIONS: Analysis of demographic, perioperative, and outcome data. Variables were compared between groups according to the level of tumor thrombus, the timing of the preoperative imaging, and the occurrence of perioperative PE. MEASUREMENTS AND MAIN RESULTS: Incidence, outcomes, and variables associated with perioperative PE and sensitivity/specificity analyses for optimized preoperative imaging timing, broken into 7-day increments, were assessed. Fifty-six patients were included in this analysis. Perioperative PE was observed in 6 (11%) patients, intraoperatively in 5 patients and in the early postoperative period in 1 patient. Of the 5 patients with intraoperative PE, 2 died intraoperatively. Perioperative PE occurred in 1 patient with tumor thrombus level I, in 2 patients with level II, in 2 patients with level III, and in 1 patient with level IV. Risks of preoperative tumor thrombus progression were minimized if the imaging study was performed within 3 weeks for level I and II tumor thrombi and within 1 week for level III tumor thrombus. CONCLUSIONS: Perioperative PE was observed in patients with all levels of tumor thrombus. Fifty percent of perioperative PE were observed in patients with infrahepatic tumor thrombus. Post-imaging progression of tumor thrombus was unlikely if the surgery was performed within 3 weeks in patients with levels I or II tumor thrombus or within 1 week in patients with level III tumor thrombus.

Factors associated with mortality within 24h of liver transplantation: An updated analysis of 65,308 adult liver transplant recipients between 2002 and 2013.

STUDY OBJECTIVES: Intracardiac and pulmonary thromboembolism (ICPTE), its risk factors and contribution to 24-hour mortality after adult liver transplantation for end-stage liver disease. DESIGN: Retrospective analysis of Standard Transplant Analysis and Research electronic database files. SETTING: Perioperative. PATIENTS: Electronic files of 65,308 adult liver transplant recipients between 2002 and 2013 obtained from Organ Procurement and Transplantation Network. INTERVENTIONS: Mortality cause analysis and design of a multivariable logistic regression model for predicting the risk of 24-hour mortality due to devastating ICPTE. MEASUREMENTS: Perioperative mortality, donor and recipient demographics, donor cause of death, graft ischemic times, etiologies of recipient end-stage liver disease, functional status, comorbidities, and laboratory values. MAIN RESULTS: 41,324 patients were included. 38,293 (92.6%) survived 30days after transplantation. Postoperative 24-hour mortality was 547 (1.3%) and 2484 (6.0%) within subsequent 30days. Uncontrolled hemorrhage (57 patients, 0.14%), devastating ICPTE (54 patients, 0.13%) and primary graft failure (49 patients, 0.12%) contributed the most and equally to the 24-hour mortality. For the ICPTE, recipients' prior history of pulmonary embolism, portal vein thrombosis, functional status (Karnofsky score) <20, preoperative ventilator support, diabetes mellitus and Asian ethnicity emerged as significant independent hazard factors on multivariable regression analysis. These risk factors were expressed as an index to calculate the overall hazard of a devastating ICPTE; c-statistics 0.70 (p<0.001). CONCLUSIONS: Devastating ICPTE contributes significantly to the 24-hour mortality after adult cadaveric liver transplantation. Its most significant risk factors could be expressed as an index with a good predictive accuracy. Further studies of perioperative factors with potential impact on ICPTE and related mortality and morbidity are needed.

Role of nitric oxide in liver transplantation: Should it be routinely used?

Ischemia-reperfusion injury (IRI) continues to be a major contributor to graft dysfunction, thus supporting the need for therapeutic strategies focused on minimizing organ damage especially with growing numbers of extended criteria grafts being utilized which are more vulnerable to cold and warm ischemia. Nitric oxide (NO·) is highly reactive gaseous molecule found in air and regarded as a pollutant. Not surprising, it is extremely bioactive, and has been demonstrated to play major roles in vascular homeostasis, neurotransmission, and host defense inflammatory reactions. Under conditions of ischemia, NO· has consistently been demonstrated to enhance microcirculatory vasorelaxation and mitigate pro-inflammatory responses, making it an excellent strategy for patients undergoing organ transplantation. Clinical studies designed to test this hypothesis have yielded very promising results that includes reduced hepatocellular injury and enhanced graft recovery without any identifiable complications. By what means NO· facilitates extra-pulmonary actions is up for debate and speculation. The general premise is that they are NO· containing intermediates in the circulation, that ultimately mediate either direct or indirect effects. A plethora of data exists explaining how NO·-containing intermediate molecules form in the plasma as S-nitrosothiols (e.g., S-nitrosoalbumin), whereas other compelling data suggest nitrite to be a protective mediator. In this article, we discuss the use of inhaled NO· as a way to protect the donor liver graft against IRI in patients undergoing liver transplantation.

Size mismatch in liver transplantation.

Size mismatch is an unique and inevitable but critical issue in live donor liver transplantation. Unmatched metabolic demand of recipient as well as physiologic mismatch aggravates the damage to liver graft, inevitably leading to graft failure on recipient. Also, an excessive resection of liver graft for better recipient outcome in live donor liver transplant may jeopardize the healthy donor well-being and even put donor life in danger. There is a fine balance between resected graft volume required to meet the recipient's metabolic demand and residual graft volume required for donor safety. The obvious clinical necessity of finding that balance has prompted a clinical need and promoted the improvement of knowledge and development of management strategies for size-mismatched transplants. The development of the size-matching methodology has significantly improved graft outcome and recipient survival in live donor liver transplants. On the other hand, the effect of size mismatch in cadaveric transplants has never been observed as being so pronounced. The importance of matching of the donor recipient size has been unrecognized in cadaveric liver transplant. In this review, we attempt to summarize the current most updated knowledge on the subject, particularly addressing the definition and complications of size-mismatched cadaveric liver transplant, as well as management strategies.

Detrimental graft survival of size-mismatched graft for high model for end-stage liver disease recipients in liver transplantation.

BACKGROUND: In orthotopic liver transplantation (OLT) size-mismatch may cause adverse outcomes. We previously reported on a method to predict donor-recipient size-mismatch using the body surface area index (BSAi). In this study, we hypothesized that graft survival of size-mismatch transplantation deteriorates with higher model for end-stage liver disease (MELD) score at transplantation. METHODS: We evaluated non-parametrically the association of BSAi and MELD with 1-year graft survival with a generalized additive model. For derivation, transplantations performed between 2005 and 2010 were used. The associations were then validated by comparing Kaplan-Meier estimates between patient groups stratified according to estimated risk, using transplantations from 2011-2013. RESULTS: A total of 30,870 OLT were included in the study with 16,466 in the validation group. The derivation model revealed that graft survival significantly decreased with higher or lower BSAi, and with higher MELD (P < 0.0001). Validation confirmed the correlation of observed graft survival with estimated risk categories. CONCLUSIONS: We found that there is an interactive effect between MELD score and size-mismatch. Also high MELD recipient has a narrower safety margin for size-mismatched graft. The risk calculated from our nonparametric model with MELD and BSAi well predicts outcome in liver transplantation.

Serum acidosis prior to reperfusion facilitates hemodynamic recovery following liver transplantation.

INTRODUCTION: Reperfusion is the most critical event during liver transplantation, and sustained leakage of acidic preservation solution from the liver graft contributes to marked hemodynamic instability. Recent laboratory studies with hepatocyte cultures have revealed that low pH may protect hepatocyte mitochondria against ischemia-reperfusion injury by inhibiting the mitochondrial permeability transition (MPT), the so-called "pH paradox." However, the clinical significance of this pH paradox theory remains largely unknown. In this study, we sought to determine whether there is an association between serum pH immediately prior to reperfusion and hemodynamic recovery after reperfusion and graft survival. METHODS: We analyzed retrospective data from 527 patients who underwent Orthotopic liver transplantation between 2003 and 2008. All patients were allocated to one of two groups: pH ≤ 7.32 or pH > 7.32, as measured 5 min before reperfusion. Case-control matching was performed using the propensity score to adjust for background differences between the two groups. Data were analyzed using Student's t-test and the χ (2) test. RESULTS: There were 85 patients in the pH ≤ 7.32 group and 385 patients in the pH > 7.32 group. The recovery of mean arterial pressure after hepatic artery reperfusion was significantly faster in the pH ≤ 7.32 group (slope of recovery: 0.0004 % vs. 0.0002 %/min, p = 0.041). Other parameters studied, including vasopressor dosage after reperfusion, did not show any statistically significant difference between groups. CONCLUSIONS: Our findings suggest that less aggressive treatment of acidosis with a slower rate of normalization of serum pH (from low to normal) after reperfusion promotes faster hemodynamic stabilization. These findings provide evidence to support the concept of the pH paradox, and may also substantiate the argument against the usage of alkalizing agents before reperfusion unless acidosis becomes clinically significant.

Hemodynamic recovery following postreperfusion syndrome in liver transplantation.

OBJECTIVES: The authors' current understanding of the phenomenon of significant and sustained decrease in arterial pressure following liver graft reperfusion (postreperfusion syndrome [PRS]), is derived from relatively small observational reports, and no large scale analysis of PRS exists up to date. This study investigated its incidence, risk factors, temporal course of hemodynamic recovery, and its impact on functional graft outcome. DESIGN: Retrospective observational study of 1,024 electronic records of orthotopic liver transplant recipients. SETTING: Major transplant center. MEASUREMENTS: Out of 1,024, 715 records satisfied the inclusion criteria. Data were analyzed by multivariable Cox's proportional hazard model to identify risk factors for PRS. Hemodynamic recovery patterns and functional graft outcomes were compared between the cohorts of interest (intraoperative PRS) and control (no intraoperative PRS) after propensity score-matching. Association between donor risk index and hemodynamic recovery after hepatic artery reperfusion was analyzed by a multivariable regression model. RESULTS: The overall incidence of PRS was 31.6% with associated mortality of 0.3%. Independent risk factors for PRS included older donor age, higher donor risk index, and lower central venous pressure at reperfusion. Hemodynamic recovery after PRS following portal vein reperfusion was delayed until hepatic artery reperfusion. The slope of hemodynamic recovery, expressed as %MAP/min, correlated negatively with donor risk index (p=0.014). Immediate and 1-year graft survival rates were similar in both cohorts. CONCLUSIONS: Host hemodynamic response to graft reperfusion appeared to be phasic: initial abrupt hypotension after portal vein reperfusion was followed by a period of gradual decline of blood pressure until hepatic artery reperfusion, and sustained hemodynamic recovery afterwards. The slope of hemodynamic recovery correlated negatively with the donor risk index. PRS was not associated with deterioration of post-transplant graft survival and function.

Peak Serum AST Is a Better Predictor of Acute Liver Graft Injury after Liver Transplantation When Adjusted for Donor/Recipient BSA Size Mismatch (ASTi).

Background. Despite the marked advances in the perioperative management of the liver transplant recipient, an assessment of clinically significant graft injury following preservation and reperfusion remains difficult. In this study, we hypothesized that size-adjusted AST could better approximate real AST values and consequently provide a better reflection of the extent of graft damage, with better sensitivity and specificity than current criteria. Methods. We reviewed data on 930 orthotopic liver transplant recipients. Size-adjusted AST (ASTi) was calculated by dividing peak AST by our previously reported index for donor-recipient size mismatch, the BSAi. The predictive value of ASTi of primary nonfunction (PNF) and graft survival was assessed by receiver operating characteristic curve, logistic regression, Kaplan-Meier survival, and Cox proportional hazard model. Results. Size-adjusted peak AST (ASTi) was significantly associated with subsequent occurrence of PNF and graft failure. In our study cohort, the prediction of PNF by the combination of ASTi and PT-INR had a higher sensitivity and specificity compared to current UNOS criteria. Conclusions. We conclude that size-adjusted AST (ASTi) is a simple, reproducible, and sensitive marker of clinically significant graft damage.

Volatile anesthetics and AKI: risks, mechanisms, and a potential therapeutic window.

AKI is a major clinical problem with extremely high mortality and morbidity. Kidney hypoxia or ischemia-reperfusion injury inevitably occurs during surgery involving renal or aortic vascular occlusion and is one of the leading causes of perioperative AKI. Despite the growing incidence and tremendous clinical and financial burden of AKI, there is currently no effective therapy for this condition. The pathophysiology of AKI is orchestrated by renal tubular and endothelial cell necrosis and apoptosis, leukocyte infiltration, and the production and release of proinflammatory cytokines and reactive oxygen species. Effective management strategies require multimodal inhibition of these injury processes. Despite the past theoretical concerns about the nephrotoxic effects of several clinically utilized volatile anesthetics, recent studies suggest that modern halogenated volatile anesthetics induce potent anti-inflammatory, antinecrotic, and antiapoptotic effects that protect against ischemic AKI. Therefore, the renal protective properties of volatile anesthetics may provide clinically useful therapeutic intervention to treat and/or prevent perioperative AKI. In this review, we outline the history of volatile anesthetics and their effect on kidney function, briefly review the studies on volatile anesthetic-induced renal protection, and summarize the basic cellular mechanisms of volatile anesthetic-mediated protection against ischemic AKI.

Invasive renal cell carcinoma with inferior vena cava tumor thrombus: cardiac anesthesia in liver transplant settings.

OBJECTIVES: Resection of renal cell carcinomas (RCC) with tumor thrombus invasion into the inferior vena cava (IVC) is associated with significant perioperative morbidity and mortality. This study examined the intra- and inter-departmental collaboration among cardiac, liver transplantation, and urologic surgeons and anesthesiologists in caring for these patients. DESIGN: After IRB approval, medical records of patients who underwent resection of RCC tumor thrombus level III and IV, from 1997 to 2010 in this institution, were reviewed. Data were collected and analyzed by one way-ANOVA and chi-square test. SETTING: Major academic institution, tertiary referral center. PARTICIPANTS: This was a retrospective study based on the medical records of patients who underwent resection of RCC tumor thrombus level III and IV, from 1997 to 2010. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Fifty-eight patients (82.9%) with level III thrombus and 12 patients (17.1%) with level IV thrombus were analyzed. Sixty-five (92.9%) did not require any extracorporeal circulatory support; 5 (2 with level III and 3 with level IV; 7.1%) required cardiopulmonary bypass. No patients required veno-venous bypass. Compared to patients with level III thrombus extension, patients with level IV had higher estimated blood loss (6978±2968 mL v 1540±206, p<0.001) and hospital stays (18.8±1.6 days v 8.1±0.7, p<0.001). Intraoperative transesophageal echocardiography (TEE) was utilized in 77.6% of patients with level III thrombus extension and in 100% of patients with level IV thrombus extension. Intraoperative TEE guidance resulted in a significant surgical plan modification in 3 cases (5.2%). Short-term mortality was low (n = 3, 4.3%). CONCLUSIONS: Utilization of specialized liver transplantation and cardiac surgical techniques in the resection of RCC with extension into the IVC calls for a close intra-and interdepartmental collaboration between surgeons and anesthesiologists. The transabdominal approach to suprahepatic segments of the IVC allowed avoidance of extracorporeal circulatory support in most of these patients. Perioperative management of these patients reflected the critical importance of TEE-proficient practitioners experienced in liver transplantation and cardiac anesthesia.

Coronary artery disease and its risk factors in patients presenting for liver transplantation.

STUDY OBJECTIVE: To determine the distribution of coronary artery disease (CAD) and its risk factors across the various etiologies of end-stage liver disease, and to elucidate the relationship between severe alcohol consumption and CAD. DESIGN: Retrospective multicenter study analysis. SETTING: National Standard Transplant Analysis and Research file data. MEASUREMENTS: Data from all primary adult orthotopic liver transplant recipients during the period from 2004 through 2006 were studied. Data were divided into 5 groups according to each patient's etiology of end-stage liver disease. The prevalence of CAD and the distribution of its risk factors were compared among groups. MAIN RESULTS: 17,482 cases were studied. The incidence of CAD was highest in nonalcoholic hepatic steatosis (7.4%) and lowest in biliary cirrhosis (1.7%). No difference in prevalence of CAD and its risk factors was noted between the viral and alcoholic etiologies (Hepatitis C 2.7%, Hepatitis B 2.3%, and alcoholic cirrhosis 2.9%). CONCLUSIONS: Prevalence of CAD and the distribution of CAD risk factors in patients with severe alcohol consumption were similar to patients with viral hepatitis. CAD was most prevalent in patients with hepatic steatosis. This study argues against the notion of decreased expression and progression of CAD in patients with alcoholic cirrhosis presenting for liver transplantation.

Long-term deleterious effects of aortohepatic conduits in primary liver transplantation: proceed with caution.

Aortohepatic conduits provide a vital alternative for graft arterialization during liver transplantation. Conflicting results exist with respect to the rates of comorbidities, and long-term survival data on primary grafts are lacking. To identify the complications associated with aortohepatic conduits in primary liver transplantation and their impact on survival, we conducted a single-center, retrospective cohort analysis of all consecutive adult (n = 1379) and pediatric primary liver transplants (n = 188) from 1998 to 2009. The outcomes of aortohepatic conduits were compared to those of standard arterial revascularization. Adults with a conduit (n = 267) demonstrated, in comparison with adults with standard arterialization (n = 1112), an increased incidence of late (>1 month after transplantation) hepatic artery thrombosis (HAT; 4.1% versus 0.7%, P < 0.001) and ischemic cholangiopathy (7.5% versus 2.7%, P < 0.001) and a lower 5-year graft survival rate (61% versus 70%, P = 0.01). The adjusted hazard ratio (HR) for graft loss in the conduit group was 1.38 [95% confidence interval (CI) = 1.03-1.85, P = 0.03]. Notably, the use of conduits (HR = 4.91, 95% CI = 1.92-12.58) and a warm ischemia time > 60 minutes (HR = 11.12, 95% CI = 3.06-40.45) were independent risk factors for late HAT. Among children, the complication profiles were similar for the conduit group (n = 81) and the standard group (n = 107). In the pediatric cohort, although the 5-year graft survival rate for the conduit group (69%) was significantly impaired in comparison with the rate for the standard group (81%, P = 0.03), the use of aortohepatic conduits did not emerge as an independent predictor of diminished graft survival via a multivariate analysis. In conclusion, in adult primary liver transplantation, the placement of an aortohepatic conduit should be strictly limited because of the greater complication rates (notably late HAT) and impaired graft survival; for children, its judicious use may be acceptable.

Determination of the safe range of graft size mismatch using body surface area index in deceased liver transplantation.

In live donor liver transplantation, rigorous standardized criteria for matching of liver volume between donor and recipient have prevented graft loss because of size mismatch. In deceased whole liver transplantation, the safe donor-recipient size mismatch range remains unknown. We developed a multivariate survival model (generalized additive model) to estimate hazard risk of body surface area index (BSAi) for 3-year graft survival using data derived from the national registry database between 2005 and 2010. BSAi was calculated by BSA of donor divided by BSA of recipient. 24 509 patients were included in the analysis. Small-for-size (SFS) grafts with BSAi less than 0.78 had a significant impact on graft dysfunction with progressive increase of hazard risk toward the lowest end and a higher incidence of primary graft nonfunction and vascular thrombosis. Large-for-size (LFS) grafts with BSAi greater than 1.24 had a significant impact on graft dysfunction with progressive increase of hazard risk toward the largest end. Our findings suggest that donor grafts with BSAi < 0.78 could be considered 'SFS' and donor grafts with BSAi > 1.24 could be considered 'LFS', with both extremes resulting in decreased graft survival. Therefore, BSAi > 0.78 and <1.24 appears to be a safe range to avoid adverse outcome associated with size mismatch.

Crystalloid flush with backward unclamping may decrease post-reperfusion cardiac arrest and improve short-term graft function when compared to portal blood flush with forward unclamping during liver transplantation.

During liver transplant (LT), the release of vasoactive substances into the systemic circulation is associated with severe hemodynamic instability that is injurious to the recipient and/or the post-ischemic graft. Crystalloid flush with backward unclamping (CB) and portal blood flush with forward unclamping (PF) are two reperfusion methods to reduce reperfusion-related cardiovascular perturbations in our center. The primary aim of this study was to compare these two methods. After institutional review board (IRB) approval, cadaveric whole LT cases performed between 2003 and 2008 were reviewed. Patients were divided into two groups based on reperfusion methods: CB or PF. After background matching with propensity score, the effect of each method on post-operative graft function was assessed in detail. In our cohort of 478 patients, CB was used in 313 grafts and PF in 165. Thirty-day graft survival was lower, and risk of retransplantation was higher in PF. Multivariable model showed that CB is an independent factor to reduce primary non-function, cardiac arrest and improve 30-d graft survival. Also, the incidence of ischemic-type biliary lesions was significantly higher in the PF group. Reperfusion methods affect intraoperative hemodynamics and post-transplant outcome. CB allows for control over temperature and composition of the perfusate, perfusion pressure, and the rate of infusion.