Hemodynamic Instability During Liver Transplantation in Patients With End-stage Liver Disease: A Consensus Document from ILTS, LICAGE, and SATA

Perioperative Variation of Plasma Copeptin and Its Association With Vasopressor Need During Liver Transplantation

BACKGROUND

Vasopressor usage during liver transplant is related to decreased hepatic flow, graft failure, and mortality. We measured plasma Copeptin levels in liver transplant patients based on vasopressor requirements. We hypothesize that preoperative plasma copeptin measurement helps predict the vasopressor infusion requirement during liver transplantation in preoperative evaluation.

METHODS

The plasma Copeptin of 40 patients was measured 5 times: before the operation, 15 minutes before and after reperfusion, and postoperative 12th and 24th hours. Patients were categorized into 2 groups based on vasopressor infusion for comparison.

RESULTS

There was a statistically significant rise in median serum Copeptin concentration between the preoperative phase and before reperfusion (11.2 [7.3-20.9] vs 178.5 [121.5-243.0], P < .001), as well as a statistically substantial decline between after reperfusion and postoperative 12th hours (190.6 [127-276.3] vs 74.7 [42.0-124.9], P < .001). The vasopressor-taking group had significantly higher plasma copeptin at postoperative 12th hours (96.6 [71.4-191.7] vs 55.0 [31.8-82.5], P = .030) and 24th (133.7 [72.2-175.5] vs 51.1 [24.8-85.8], P = .037). A tendency above 11.85 pmol/L of plasma Copeptine level was observed between increasing preoperative plasma Copeptin and the odds of vasopressor use.

CONCLUSION

High preoperative plasma Copeptin levels may be an indicator of vasopressor need during liver transplantation. Further studies with more samples, including a higher range of preoperative plasma Copeptin levels, are required to provide more generalizable findings and to determine thresholds applicable to LT candidates.

A Review of Cardiac Preoperative Screening Guidelines for Liver Transplantation

Orthotopic liver transplant (OLT) medicine is a constantly evolving field, especially with the demographics of individuals with advanced liver disease drastically changing. OLT candidates are now older, and there is an increase of nonalcoholic steatohepatitis cirrhosis due to the epidemic of obesity, which has also resulted in an increase in cardiac comorbidities in this population. The pathophysiology of liver cirrhosis creates many complexities during the pre- and postoperative management of OLT. We discuss the role of screening for common co-existent cardiovascular comorbidities, including coronary artery disease, congestive heart failure, arrhythmias, and portopulmonary hypertension, as well as challenges in the standardization of pre-liver transplant cardiovascular care.

Current Concepts in Fluid Resuscitation and Vasopressor Use in Cirrhosis

Critically ill patients with cirrhosis and liver failure do not uncommonly have hypotension due to multifactorial reasons, which include a hyperdynamic state with increased cardiac index (CI), low systemic vascular resistance (SVR) due to portal hypertension, following the use of beta-blocker or diuretic therapy, and severe sepsis. These changes are mediated by microvascular alterations in the liver, systemic inflammation, activation of renin-angiotensin-aldosterone system, and vasodilatation due to endothelial dysfunction. Haemodynamic assessment includes measuring inferior vena cava indices, cardiac output (CO), and SVR using point-of-care ultrasound (POCUS), arterial waveform analysis, pulmonary artery pressures, and lactate clearance to guide fluid resuscitation. Fluid responsiveness reflects the ability of fluid bolus to increase the CO and is assessed effectively by POCUS, passive leg raises manoeuvre, and dynamic tests such as pulse pressure and stroke volume variation in spontaneously breathing and mechanically ventilated patients. Albumin has pleiotropic benefits through anti-inflammatory properties besides its standard action on oncotic pressure and volume expansion in patients with cirrhosis but has the potential for precipitating pulmonary oedema. In conclusion, fluid therapy in critically ill patients with liver disease is a complex and dynamic process that requires individualized management protocols to optimize patient outcomes.

Relevance of perioperative fluid dynamics in liver transplantation to acute kidney injury and patient outcomes: a cross-sectional survey

Background

Fluid administration is a critical component of perioperative management for liver transplant recipients, and excessive fluid infusion can lead to acute kidney injury (AKI) and poor patient outcomes.

Method

We conducted a cross-sectional survey on the fluid intake and output of adult liver transplant recipients over a 7-day period. The patients were divided into AKI and non-AKI groups. Multivariate logistic regression analyses were used to evaluate the association between fluid balance (FB) and AKI. A Kaplan-Meier survival analysis was performed to determine the survival of the recipient survival at 180 days.

Results

A total of 210 liver transplant recipients were included. The peak FB occurred on the second day after transplantation, which was higher than on the seventh day (0.3 [IQR, -0.2 to 0.8] L vs. -0.4 [IQR, -1.0 to 0.3] L, p < 0.001). The highest incidence of AKI was observed on the second day after transplantation and the lowest on the seventh day (52.4% vs. 15.4%, p < 0.001). Multivariate analysis showed that a cumulative FB > 1 L within the first 2 days postoperatively was an independent risk factor for AKI on the second day after liver transplantation (LT) (OR = 2.66, 95% CI, 1.31-5.41, p = 0.007). Survival analysis indicated significant differences in 180-day survival rates among patients with different grades of AKI [94.0% (grade 1) vs. 91.4% (grade 2) vs. 77.8% (grade 3), χ 2  = 12.93, p < 0.001].

Conclusion

There is a significant correlation between post-LT AKI and perioperative FB. Cumulative FB > 1 L in the first 2 days postoperatively is an independent risk factor for AKI on the second day after LT. AKI after LT is associated with a lower 180-day survival rate in patients.

Management of the liver transplant candidate with high cardiac risk: Multidisciplinary best practices and recommendations

In a setting characterized by a growing prevalence of patients with alcohol-associated and metabolic dysfunction-associated steatotic liver diseases, coupled with an aging patient demographic, the incidence of cardiac comorbidities in liver transplant candidates is on the rise. These comorbidities not only pose barriers to transplant eligibility but also impact the intraoperative course and affect posttransplant outcomes. As such, there is a significant need to optimize the clinical management of these cardiac comorbidities. However, there is a scarcity of evidence regarding the best practices for managing cardiac comorbidities such as coronary and valvular heart diseases, arrhythmia, and cardiomyopathy in this population, both before and during transplant surgery. These conditions necessitate a coordinated and multidisciplinary approach to care. In this manuscript, we conduct a comprehensive review of the most recent evidence pertaining to the preoperative and intraoperative management of these cardiac comorbidities in liver transplant candidates. Our aim is to provide recommendations that improve and standardize their clinical care.

Anesthesia for Combined Heart-Liver Transplantation: A Narrative Review

In 1984, 21 years after the first liver transplantation, Thomas Starzl achieved a milestone by performing the world's first combined heart-liver transplantation. While still uncommon, the practice of combined heart-liver transplants is on the rise globally. In this review, the authors delve into the current literature on this procedure, highlighting the evolving landscape and key considerations for anesthesiologists. Over the years, there has been a remarkable increase in the number of combined heart-liver transplantations conducted worldwide. This surge is largely attributed to the growing population of adult survivors with single-ventricle physiology, palliated with a Fontan procedure, who later present with late Fontan failure and Fontan-associated liver disease. Research indicates that combined heart-liver transplantation is an effective treatment option, with reported outcomes comparable with isolated heart or liver transplants. Managing anesthesia during a combined heart-liver transplant procedure is challenging, especially in the context of underlying Fontan physiology. International experience in this field remains somewhat limited, with most techniques derived from expert opinions or experiences with single-organ heart and liver transplants. These procedures are highly complex and performed infrequently. As the number of combined heart-liver transplants continues to rise globally, there is a growing need for clear guidance on periprocedural surgical and anesthetic management. Anesthesiologists overseeing these patients must consider multiple factors, balancing various comorbidities with significant hemodynamic and metabolic shifts. An increase in (multicenter) studies focusing on specific interventions to enhance patient and organ outcomes is anticipated in the coming years.

Intraoperative hypotension during liver transplantation and postoperative outcomes: Retrospective cohort study

STUDY OBJECTIVES

Evaluation of the association between intraoperative hypotension (IOH) and important postoperative outcomes after liver transplant such as incidence and severity of acute kidney injury (AKI), MACE and early allograft dysfunction (EAD).

DESIGN

Retrospective, single institution study.

SETTINGS

Operating room.

PATIENTS

1576 patients who underwent liver transplant in our institution between January 2005 and February 2022.

MEASUREMENTS

IOH was measured as the time, area under the threshold (AUT), or time-weighted average (TWA) of mean arterial pressure (MAP) less than certain thresholds (55,60 and 65 mmHg). Associations between IOH exposures and AKI severity were assessed via proportional odds models. The odds ratio from the proportional odds model estimated the relative odds of having higher stage of AKI for higher exposure to IOH. Associations between exposures and MACE and EAD were assessed through logistic regression models. Potential confounding variables including patient baseline and surgical characteristics were adjusted for all models.

MAIN RESULTS

The primary analysis included 1576 surgeries that met the inclusion and exclusion criteria. Of those, 1160 patients (74%) experienced AKI after liver transplant surgery, with 780 (49%), 248(16%), and 132 (8.4%) experiencing mild, moderate, and severe injury, respectively. No significant association between hypotension exposure and postoperative AKI (yes or no) nor severity of AKI was observed. The odds ratios (95% CI) of having more severe AKI were 1.02 (0.997, 1.04) for a 50-mmHg·min increase in AUT of MAP <55 mmHg (P = 0.092); 1.03 (0.98, 1.07) for a 15-min increase in time spent under MAP <55 mmHg (P = 0.27); and 1.24 (0.98, 1.57) for a 1 mmHg increase in TWA of MAP <55 mmHg (P = 0.068). The associations between IOH and the incidence of MACE or EAD were not significant.

CONCLUSION

Our results did not show the association between IOH and investigated outcomes.

Congestive colopathy in a patient with arteriovenous malformations and multiple mesenteric thromboses

Arteriovenous malformations (AVMs) in mesenteric vessels are exceptionally rare. These congenital vascular anomalies lead to direct vascular flow between the highly pressured arterial system and the low-pressure venous system. We describe the case of a patient with prior left colectomy for splenic flexure colonic adenocarcinoma presenting with persistent abdominal pain after developing multiple mesenteric thromboses. CT and colonoscopy showed left hemicolon congestion, anastomotic stenosis and mucosal oedema. Mesenteric angiogram revealed AVMs in the right colic and left colic arteries. Embolisation of the left colic AVM led to symptom resolution without recurrence at interval follow-up.

Angiotensin II as a Vasopressor for Perioperative Hypotension in Solid Organ Transplant

During the perioperative period of transplantation, patients experience hypotension secondary to the side effects of anesthesia, surgical stress, inflammatory triggering, and intraoperative fluid shifts, among others causes. Vasopressor support, in this context, must reverse systemic hypotension, but ideally, the agents used should benefit allograft function and avoid the adverse events commonly seen after transplantation. Traditional therapies to reverse hypotension include catecholamine vasopressors (norepinephrine, epinephrine, dopamine, and phenylephrine), but their utility is limited when considering allograft complications and adverse events such as arrhythmias with agents with beta-adrenergic properties. Synthetic angiotensin II (AT2S-[Giapreza]) is a novel vasopressor indicated for distributive shock with a unique mechanism of action as an angiotensin receptor agonist restoring balance to an often-disrupted renin angiotensin aldosterone system. Additionally, AT2S provides a balanced afferent and efferent arteriole vasoconstriction at the level of the kidney and could avoid the arrhythmic complications of a beta-adrenergic agonist. While the data, to date, are limited, AT2S has demonstrated safety in case reports, pilot studies, and small series in the kidney, liver, heart, and lung transplant populations. There are physiologic and hemodynamic reasons why AT2S could be a more utilized agent in these populations, but further investigation is warranted.

Anaesthesia management for liver transplantation: A narrative review

Orthotopic liver transplantation is the definitive standard treatment for end-stage liver disease. Orthotopic liver transplantation anaesthesia management is a complex procedure that requires a multidisciplinary team approach. Understanding the complex pathophysiology of end-stage liver disease and its complications in the affected systems is essential for proper anaesthesia management in orthotopic liver transplantation. Orthotopic liver transplantation is a dynamic process, and preoperative optimisation is essential in these patients. Therefore, anaesthesiologists should focus on rapidly fluctuating physiology, haemodynamics, metabolic, and coagulation status in the anaesthesia management of these patients. Perioperative care and anaesthesia for orthotopic liver transplantation can be divided into preoperative evaluation, anaesthesia induction and management, dissection, anhepatic, neo-hepatic, and postoperative care, with essential anaesthetic considerations at each point. Considering the clinical situation, haemodynamic changes, misapplications, knowledge, attitude, and multimodal and multidisciplinary approach are vital in anaesthesia and the perioperative period. In our review, in line with the literature, we aimed to present the perioperative and anaesthesia management in orthotopic liver transplantation patients.

Hemodynamic monitoring in liver transplantation 'the hemodynamic system'

PURPOSE OF REVIEW

The purpose of this article is to provide a comprehensive review of hemodynamic monitoring in liver transplantation.

RECENT FINDINGS

Radial arterial blood pressure monitoring underestimates the aortic root arterial blood pressure and causes excessive vasopressor and worse outcomes. Brachial and femoral artery monitoring is well tolerated and should be considered in critically ill patients expected to be on high dose pressors. The pulmonary artery catheter is the gold standard of hemodynamic monitoring and is still widely used in liver transplantation; however, it is a highly invasive monitor with potential for serious complications and most of its data can be obtained by other less invasive monitors. Rescue transesophageal echocardiography relies on few simple views and should be available as a standby to manage sudden hemodynamic instability. Risk of esophageal bleeding from transesophageal echocardiography in liver transplantation is the same as in other patient populations. The arterial pulse waveform analysis based cardiac output devices are minimally invasive and have the advantage of real-time beat to beat monitoring of cardiac output. No hemodynamic monitor can improve clinical outcomes unless integrated into a goal-directed hemodynamic therapy. The hemodynamic monitoring technique should be tailored to the patient's medical status, surgical technique, and the anesthesiologist's level of expertise.

SUMMARY

The current article provides a review of the current hemodynamic monitoring systems and their integration in goal-directed hemodynamic therapy.

Aborted living-donor liver transplantation in the real-world setting, lessons from 13 937 cases of Vanguard Multi-center Study of International Living Donor Liver Transplantation Group

There are exceedingly uncommon but clearly defined situations where intraoperative abortions are inevitable in living-donor liver transplantation (LDLT). This study aimed to summarize the cases of aborted LDLT and propose a strategy to prevent abortion or minimize donor damage from both recipient and donor sides. We collected data from a total of 43 cases of aborted LDLT out of 13 937 cases from 7 high-volume hospitals in the Vanguard Multi-center Study of the International Living Donor Liver Transplantation Group and reviewed it retrospectively. Of the 43 cases, there were 24 recipient-related abortion cases and 19 donor-related cases. Recipient-related abortions included pulmonary hypertension (n = 8), hemodynamic instability (n = 6), advanced hepatocellular carcinoma (n = 5), bowel necrosis (n = 4), and severe adhesion (n = 1). Donor-related abortions included graft steatosis (n = 7), graft fibrosis (n = 5), primary biliary cholangitis (n = 3), anaphylactic shock (n = 2), and hemodynamic instability (n = 2). Total incidence of aborted LDLT was 0.31%, and there was no remarkable difference between the centers. A strategy to minimize additional donor damage by delaying the donor's laparotomy or trying to open the recipient's abdomen with a small incision should be effective in preventing some causes of aborted LDLT, such as pulmonary hypertension, advanced cancer, and severe adhesions.

Angiotensin II in liver transplantation (AngLT-1): protocol of a randomised, double-blind, placebo-controlled trial

INTRODUCTION

Catecholamine vasopressors such as norepinephrine are the standard drugs used to maintain mean arterial pressure during liver transplantation. At high doses, catecholamines may impair organ perfusion. Angiotensin II is a peptide vasoconstrictor that may improve renal perfusion pressure and glomerular filtration rate, a haemodynamic profile that could reduce acute kidney injury. Angiotensin II is approved for vasodilatory shock but has not been rigorously evaluated for treatment of hypotension during liver transplantation. The objective is to assess the efficacy of angiotensin II as a second-line vasopressor infusion during liver transplantation. This trial will establish the efficacy of angiotensin II in decreasing the dose of norepinephrine to maintain adequate blood pressure. Completion of this study will allow design of a follow-up, multicentre trial powered to detect a reduction of organ injury in liver transplantation.

METHODS AND ANALYSIS

This is a double-blind, randomised clinical trial. Eligible subjects are adults with a Model for End-Stage Liver Disease Sodium Score ≥25 undergoing deceased donor liver transplantation. Subjects are randomised 1:1 to receive angiotensin II or saline placebo as the second-line vasopressor infusion. The study drug infusion is initiated on reaching a norepinephrine dose of 0.05 µg kg-1 min-1 and titrated per protocol. The primary outcome is the dose of norepinephrine required to maintain a mean arterial pressure ≥65 mm Hg. Secondary outcomes include vasopressin or epinephrine requirement and duration of hypotension. Safety outcomes include incidence of thromboembolism within 48 hours of the end of surgery and severe hypertension. An intention-to-treat analysis will be performed for all randomised subjects receiving the study drug. The total dose of norepinephrine will be compared between the two arms by a one-tailed Mann-Whitney U test.

ETHICS AND DISSEMINATION

The trial protocol was approved by the local Institutional Review Board (#20-30948). Results will be posted on ClinicalTrials.gov and published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ClinicalTrials.govNCT04901169.

Comparison of invasive and non-invasive measurements of cardiac index and systemic vascular resistance in living-donor liver transplantation: a prospective, observational study

BACKGROUND

Based on the controversy surrounding pulmonary artery catheterization (PAC) in surgical patients, we investigated the interchangeability of cardiac index (CI) and systemic vascular resistance (SVR) measurements between ClearSight™ and PAC during living-donor liver transplantation (LDLT).

METHODS

This prospective study included consecutively selected LDLT patients. ClearSight™-based CI and SVR measurements were compared with those from PAC at seven LDLT-stage time points. ClearSight™-based systolic (SAP), mean (MAP), and diastolic (DAP) arterial pressures were also compared with those from femoral arterial catheterization (FAC). For the comparison and analysis of ClearSight™ and the reference method, Bland-Altman analysis was used to analyze accuracy while polar and four-quadrant plots were used to analyze the trending ability.

RESULTS

From 27 patients, 189 pairs of ClearSight™ and reference values were analyzed. The CI and SVR performance errors (PEs) exhibited poor accuracy between the two methods (51.52 and 51.73%, respectively) in the Bland-Altman analysis. CI and SVR also exhibited unacceptable trending abilities in both the polar and four-quadrant plot analyses. SAP, MAP, and DAP PEs between the two methods displayed favorable accuracy (24.28, 21.18, and 26.26%, respectively). SAP and MAP exhibited acceptable trending ability in the four-quadrant plot between the two methods, but not in the polar plot analyses.

CONCLUSIONS

During LDLT, CI and SVR demonstrated poor interchangeability, while SAP and MAP exhibited acceptable interchangeability between ClearSight™ and FAC.

Intraoperative Factors Modifying the Risk of Postoperative Pulmonary Complications After Living Donor Liver Transplantation

BACKGROUND

The relationship between intraoperative anesthetic management and postoperative pulmonary complications (PPCs) after liver transplantation is not fully understood. We aimed to determine the intraoperative contributors to PPC.

METHODS

The retrospectively collected cohort included 605 patients who underwent living donor liver transplantation. PPCs comprised respiratory failure, respiratory infection, pulmonary edema, atelectasis (at least moderate degree), pneumothorax, and pleural effusion (at least moderate degree). The presence and type of PPC were evaluated by 2 pulmonary physicians. Logistic regression analysis was performed to determine the association between perioperative variables and PPC risk.

RESULTS

Of the 605 patients, 318 patients (52.6%) developed 486 PPCs. Multivariable analysis demonstrated that PPC risk decreased with low tidal volume ventilation (odds ratio [OR] 0.62 [0.41-0.94], P  = 0.023) and increased with greater driving pressure at the end of surgery (OR 1.08 [1.01-1.14], P  = 0.018), prolonged hypotension (OR 1.85 [1.27-2.70], P  = 0.001), and blood albumin level ≤3.0 g/dL at the end of surgery (OR 2.43 [1.51-3.92], P  < 0.001). Survival probability at 3, 6, and 12 mo after transplantation was 91.2%, 89.6%, and 86.5%, respectively, in patients with PPCs and 98.3%, 96.5%, and 93.4%, respectively, in patients without PPCs (hazard ratio 2.2 [1.3-3.6], P  = 0.004). Graft survival probability at 3, 6, and 12 mo after transplantation was 89.3%, 87.1%, and 84.3%, respectively, in patients with PPCs and 97.6%, 95.8%, and 92.7%, respectively, in patients without PPCs (hazard ratio 2.3 [1.4-3.7], P  = 0.001).

CONCLUSIONS

We found that tidal volume, driving pressure, hypotension, and albumin level during living donor liver transplantation were significantly associated with PPC risk. These data may help determine patients at risk of PPC or develop an intraoperative lung-protective strategy for liver transplant recipients.

Perioperative clinical practice in liver transplantation: a cross-sectional survey

PURPOSE

The objective of this study was to describe some components of the perioperative practice in liver transplantation as reported by clinicians.

METHODS

We conducted a cross-sectional clinical practice survey using an online instrument containing questions on selected themes related to the perioperative care of liver transplant recipients. We sent email invitations to Canadian anesthesiologists, Canadian surgeons, and French anesthesiologists specialized in liver transplantation. We used five-point Likert-type scales (from "never" to "always") and numerical or categorical answers. Results are presented as medians or proportions.

RESULTS

We obtained answers from 130 participants (estimated response rate of 71% in Canada and 26% in France). Respondents reported rarely using transesophageal echocardiography routinely but often using it for hemodynamic instability, often using an intraoperative goal-directed hemodynamic management strategy, and never using a phlebotomy (medians from ordinal scales). Fifty-nine percent of respondents reported using a restrictive fluid management strategy to manage hemodynamic instability during the dissection phase. Forty-two percent and 15% of respondents reported using viscoelastic tests to guide intraoperative and postoperative transfusions, respectively. Fifty-four percent of respondents reported not pre-emptively treating preoperative coagulations disturbances, and 91% reported treating them intraoperatively only when bleeding was significant. Most respondents (48-64%) did not have an opinion on the maximal graft ischemic times. Forty-seven percent of respondents reported that a piggyback technique was the preferred vena cava anastomosis approach.

CONCLUSION

Different interventions were reported to be used regarding most components of perioperative care in liver transplantation. Our results suggest that significant equipoise exists on the optimal perioperative management of this population.

Planned Extracorporeal Life Support Employment during Liver Transplantation: The Potential of ECMO and CRRT as Preventive Therapies-Case Reports and Literature Review

Liver Transplantation (LT) has become the gold standard treatment for End-Stage Liver Disease (ESLD). One of the main strategies to manage life-threatening complications, such as cardio-respiratory failure, is Extracorporeal Membrane Oxygenation (ECMO) in the peri-transplantation period, with different configurations of the technique and in combination with other extracorporeal care devices such as Continuous Renal Replacement Therapy (CRRT). This retrospective study includes three clinical cases of planned ECMO support strategies in LT and evaluates their application compared with current literature exploring PubMed/Medline. The three LT supported with ECMO and CRRT were performed at IRCCS Polyclinic S. Orsola-Malpighi, Bologna. All three cases of patients with compromised organ function analysed produced positive outcomes. The planned use of ECMO and CRRT support in peri-transplantation has allowed the patients to overcome contraindications and successfully undergo LT. In recent years, only a few reports have documented successful LT outcomes performed with intraoperative ECMO in critically ESLD patients. However, the management of LT with ECMO and/or CRRT assistance is an emerging challenge, with the need for more published evidence on this topic to guide treatment choices in patients with severe, acute and reversible respiratory and cardiovascular failure after LT.

Using Transesophageal Echocardiography in Liver Transplantation with Veno-Venous Bypass Is a Tool with Many Applications: A Case Series from an Italian Transplant Center

BACKGROUND

Hemodynamic instability (HDI) is common during liver transplantation (LT); veno-venous bypass (VVB) is a tool used in selected cases to ensure hemodynamic stability and for surgical needs. Transesophageal echocardiography (TEE) allows the transplant team to identify the causes of HDI and to guide therapies. We present a case series of four patients showing the valuable role of TEE during LT in VVB.

METHODS

We report four explicative cases of TEE use in LT with VVB performed at IRCCS Azienda Ospedaliero-Universitaria di Bologna. Four transplants were performed between 2016 and 2022.

RESULTS

Many authors have highlighted the diagnostic value of TEE during LT in the case of HDI. However, its specific role during LT with VVB is poorly described. This paper illustrates multiple potential uses of TEE in LT with VVB: TEE as a guide for catheterization and optimal cannula positioning, TEE as a tool for intraoperative Patent Foramen Ovale management, TEE as help for anticoagulation therapy and finally, TEE as support when evaluating bypass efficiency and correcting hypovolemia.

CONCLUSION

TEE is a useful instrument during LT with VVB. However, further studies are needed to assess the suitable applications of TEE during LT in patients with HDI requiring VVB. TEE should be part of the anesthetist's cultural background.

A brief history of liver transplantation and transplant anesthesia

In this review, we describe the major milestones in the development of organ transplantation with a specific focus on hepatic transplantation. For many years, the barriers preventing successful organ transplantation in humans seemed insurmountable. Although advances in surgical technique provided the technical ability to perform organ transplantation, limited understanding of immunology prevented successful organ transplantation. The breakthrough to success was the result of several significant discoveries between 1950 and 1980 involving improved surgical techniques, the development of effective preservative solutions, and the suppression of cellular immunity to prevent graft rejection. After that, technical innovations and laboratory and clinical research developed rapidly. However, these advances alone could not have led to improved transplant outcomes without parallel advances in anesthesia and critical care. With increasing organ demand, it proved necessary to expand the donor pool, which has been achieved with the use of living donors, split grafts, extended criteria organs, and organs obtained through donation after cardiac death. Given this increased access to organs and organ resources, the number of transplantations performed every year has increased dramatically. New regulatory organizations and transplant societies provide critical oversight to ensure equitable organ distribution and a high standard of care and also perform outcome analyses. Establishing dedicated transplant anesthesia teams results in improved organ transplantation outcomes and provides a foundation for developing new standards for other subspecialties in anesthesiology, critical care, and medicine overall. Through a century of discovery, the success we enjoy at the present time is the result of the work of well-organized multidisciplinary teams following standardized protocols and thereby saving thousands of lives worldwide each year. With continuing innovation, the future is bright.

Intraoperative Hypotension and 30-D Mortality After Liver Transplantation

Intraoperative hypotension (IOH) is common and associated with mortality in major surgery. Although patients undergoing liver transplantation (LT) have low baseline blood pressure, the relation between blood pressure and mortality in LT is not well studied. We aimed to determine mean arterial pressure (MAP) that was associated with 30-d mortality in LT.

METHODS

We performed a retrospective cohort study. The data included patient demographics, pertinent preoperative and intraoperative variables, and MAP using various metrics and thresholds. The endpoint was 30-d mortality after LT.

RESULTS

One thousand one hundred seventy-eight patients from 2013 to 2020 were included. A majority of patients were exposed to IOH and many for a long period. Eighty-nine patients (7.6%) died within 30 d after LT. The unadjusted analysis showed that predicted mortality was associated with MAP <45 to 60 mm Hg but not MAP <65 mm Hg. The association between MAP and mortality was further tested using adjustment and various duration cutoffs. After adjustment, the shortest durations for MAPs <45, 50, and 55 mm Hg associated with 30-d mortality were 6, 10, and 25 min (odds ratio, 1.911, 1.812, and 1.772; 95% confidence interval, 1.100-3.320, 1.039-3.158, and 1.008-3.114; P = 0.002, 0.036, and 0.047), respectively. Exposure to MAP <60 mm Hg up to 120 min was not associated with increased mortality.

CONCLUSION

In this large retrospective study, we found IOH was common during LT. Intraoperative MAP <55 mm Hg was associated with increased 30-d mortality after LT, and the duration associated with postoperative mortality was shorter with lower MAP than with higher MAP.

Abdominal Organ Transplantation: Noteworthy Literature in 2021

This review highlights noteworthy literature pertinent to anesthesiologists and critical care physicians caring for patients undergoing abdominal organ transplantation. In 2021, we identified noteworthy papers from over 1,200 peer-reviewed publications on pancreatic transplantation, over 1,400 on intestinal transplantation, and over 9,000 on kidney transplantation. The liver transplantation section focuses on clinical trials and systematic reviews and meta-analyses published in 2021 and features 20 selected papers. COVID-19 and abdominal organ transplantation are featured in an independent section.

New onset nonischemic cardiomyopathy post liver transplantation

A new onset acute heart failure (HF) with a sudden drop in the left ventricular ejection fraction (LVEF) post orthotopic liver transplant (LT) is a rare but a potentially fatal complication. Because in most of the cases there is no evidence of coronary thrombosis, it can be classified as nonischemic cardiomyopathy. More specifically, clinical presentation of this syndrome shares many features with stress-induced or takotsubo cardiomyopathy. The known factors that predispose these patients to acute HF during or shortly after LT include cirrhotic cardiomyopathy, rapid hemodynamic changes during LT surgery, and the large concentrations of catecholamines, either administered or released endogenously during surgery. The hemodynamic changes during surgery, such as the drop in preload during the anhepatic phase (occasionally requiring massive transfusions and vasopressors) and subsequent increase in preload with acidic and hyperkalemic plasma in the reperfusion phase, lead to rapid electrolyte and hemodynamic shifts. In several cases, intraoperative onset of HF, with or without ventricular arrythmia, could be timed to the reperfusion phase (and occasionally in the anhepatic and pre-anhepatic phases). In other cases, the HF syndrome started hours to days post-surgery. Recovery of cardiac function occurred in the majority of patients during the same admission; however, these patients generally need significantly longer hospitalizations and aggressive supportive care (occasionally requiring mechanical ionotropic and ventilatory support). If recover, the patients have a similar 1-year mortality as those LT patients that did not have this complication. Because no reliable risk stratification currently exists, intraoperative transesophageal echocardiography might be the most dependable way of detecting and addressing this syndrome promptly. Given the mechanism of takotsubo cardiomyopathy, beta-blockade and a preferential use of non-catecholaminergic vasopressors may be a reasonable way to manage this syndrome.