Transesophageal echocardiography during orthotopic liver transplantation: maximizing information without the distraction

Use of Transesophageal Echocardiography During Orthotopic Liver Transplantation: Simplifying the Procedure

The intraoperative management of patients undergoing orthotopic liver transplantation (OLT) is influenced by the cardiovascular manifestations typically found in the context of end-stage liver disease, by the presence of concomitant cardiovascular disease, and by the significant hemodynamic changes that occur during surgery. Hypotension and intraoperative blood pressure fluctuations during OLT are associated with liver graft dysfunction, acute kidney failure, and increased risk of 30-d mortality. Patients also frequently present hemodynamic instability due to various causes, including cardiac arrest. Recent evidence has shown transesophageal echocardiography (TEE) to be a useful minimally invasive monitoring tool in patients undergoing OLT that gives valuable real-time information on biventricular function and volume status and can help to detect OLT-specific complications or situations. TEE also facilitates rapid diagnosis of life-threatening conditions in each stage of OLT, which is difficult to identify with other types of monitoring commonly used. Although there is no consensus on the best approach to intraoperative monitoring in these patients, intraoperative TEE is safe and useful and should be recommended during OLT, according to experts, for assessing hemodynamic changes, identifying possible complications, and guiding treatment with fluids and inotropes to achieve optimal patient care.

Disseminated intravascular coagulation following air embolism during orthotropic liver transplantation: is this just a coincidence?

BACKGROUND

During orthotopic liver transplantation, venous air embolism may occur due to iatrogenic injury of the inferior vena cava. However, venous air embolism followed by coagulopathy is a rare event. In this case report, we discuss a possible connection between venous air embolism and disseminated intravascular coagulation.

CASE PRESENTATION

A 37-year-old male patient with chronic hepatitis B- and C-induced liver cirrhosis was admitted for orthotopic liver transplantation. During the dissection phase of the surgery, arterial blood pressure, heart rate, saturation and end-tidal carbon dioxide levels suddenly decreased, indicating the occurrence of venous air embolism. After stabilizing the patient's condition, various coagulation issues started developing. Venous air embolism-induced coagulopathy was handled by administering transfusions of various blood products. However, the patient's condition continued to deteriorate leading to a complete asystole.

CONCLUSIONS

This is a rare case of venous air embolism-induced disseminated intravascular coagulation. The real connection remains unclear as disseminated intravascular coagulation for end-stage liver disease patients can be induced by various causes during different stages of liver transplantation. Certainly, both venous air embolism and coagulopathy were significant and led to an unfavorable outcome. Further studies are needed to better understand the possible mechanisms and correlation between these two life-threatening complications.

The Prognostic Role of Right Ventricular Stroke Work Index during Liver Transplantation

Right heart-associated hemodynamic parameters including intraoperative pulmonary vascular resistance (PVR) were reported to be associated with patient survival after liver transplantation. We investigated whether intraoperative stroke work indexes of both ventricles could have a better prognostic value than PVR. We reviewed 683 cases at a tertiary care academic medical center. We collected intraoperative variables of baseline central venous pressure, baseline right ventricle end-diastolic volume, mixed venous oxygen saturation, intraoperative PVR and right and left ventricular stroke work indexes. Time-weighted means or area under the curve of intraoperative right and left ventricular stroke work indexes were calculated as exposure variables. One-year all-cause mortality or graft failure was our primary outcome. Cox proportional hazard regression analysis was performed to evaluate the association between exposure variables and one-year all-cause mortality or graft failure. Kaplan–Meier survival curve analysis of our primary outcome was performed for different time-weighted mean ventricular stroke work index groups. Cubic spline curve analysis was performed to evaluate the linear relationship between our exposure variables and primary outcome. Time-weighted mean right ventricular stroke work index was significantly associated with one-year all-cause mortality or graft failure (hazard ratio 1.21, 95% confidence interval (CI) 1.12–1.36, p < 0.001). However, there was no significant association between time-weighted mean left ventricular stroke work index, time-weighted mean PVR, PVR at the end of surgery and one-year mortality. Area under the curve of right ventricular stroke work index was also significantly associated with one-year mortality or graft failure (hazard ratio 1.24, 95% CI 1.15–1.37, p < 0.001). Kaplan–Meier survival curve analysis showed a significant difference in the survival between different mean right ventricular stroke work index groups (Log-rank test: p = 0.002). Cubic spline function curve showed the gradual increase in the risk of mortality with a positive slope with time-weighted mean right ventricular stroke work index. In conclusion, intraoperative elevated right ventricular stroke work index was significantly associated with poor patient or graft survival after liver transplantation. Intraoperative right ventricular stroke work index could be an intraoperative hemodynamic goal and prognostic marker for mortality after liver transplantation.

Nontraditional Transesophageal Echocardiographic Views to Evaluate Hepatic Vasculature in Orthotopic Liver Transplantation and Liver Resection Surgery

Background

Utilization of intraoperative transesophageal echocardiography (TEE) during orthotopic liver transplantation (OLT) is expanding annually in high-volume transplant centers. During OLT intraoperative TEE is used to gather real-time information on cardiovascular function and intravascular volume status. Although standardized TEE views exist, there are nontraditional views described in the literature which have the potential to diagnose evolving pathology and define normal variants of hepatic vasculature.

Methods

A literature review was completed utilizing the PubMed database for English-only, peer-reviewed publications discussing nontraditional use of intraoperative TEE during OLT and hepatic vascular-related surgeries from 2009 to 2019. Both case reports and review articles were considered.

Results

The PubMed literature search offered 8 publications for analysis, including 7 case reports and 1 article review, revealing several nontraditional TEE views not included in a comprehensive transesophageal echocardiographic examination. These nontraditional views were generally obtained using modifications to the transgastric and bicaval views to visualize liver vasculature. We present the various techniques for obtaining these views from the 8 articles identified.

Conclusions

At high-volume transplant centers, TEE use during OLT is increasing. Intraoperative TEE is a valuable tool to assess hepatic vascular structures critical to allograft/organ function without interruption of the surgical procedure. Nontraditional use of TEE to diagnose intraoperative noncardiac pathology in OLT appears underutilized and underreported. The modified hepatic and modified transgastric views we describe can be used to evaluate hepatic vasculature, influence surgical decision-making and ultimately improve patient care.

Validation of electrical velocimetry in resuscitation of patients undergoing liver transplantation. Observational study

Major hemodynamic changes are frequently noted during liver transplantation (LT). We evaluated the performance of electrical velocimetry (EV) as compared to that of TEE in SV optimization during liver transplantation. This was an observational study in 32 patients undergoing LT. We compared SV values measured simultaneously by EV (SV_EV) and TEE (SV_TEE) at baseline 30 min after induction, at the end of dissection phase, 30 min after anhepatic phase, 30 min after reperfusion. We also evaluated the reliability of EV to track changes In SV before and after 49 fluid challenges. Finally, the SV variation (SVV) and pulse pressure variation (PPV) were tested as predictors for volume responsiveness, defined as an increase in SV ≥ 10% after 250 ml of colloid. For 112 paired SV data, the overall correlation was 0.76 and bias (limits of agreement) 0.3 (- 29 to 29) ml percentage error 62%. The EV was able to track changes in SV with a concordance rate of 97%, and a sensitivity and specificity of 93% to detect a positive fluid challenge. The AUC values (with 95% confidence intervals) for SVV and PPV were 0.68 (0.52-0.83) and 0.72 (0.57-0.86), respectively, indicating low predictive capacity in these setting. The absolute values of SV derived from EV did not agree with SV derived from TEE. However, EV was able to track the direction of changes in SV during hemodynamic management of patients undergoing liver transplantation.Clinical trial registration: Clinicaltrials.gov Identifier: NCT03228329 prospectively Registered on 13-July-2017.

Transesophageal ultrasonography during orthotopic liver transplantation: Show me more

The first perioperative transesophageal echocardiography (TEE) guidelines published 21 years ago were mainly addressed to cardiac anesthesiologists. TEE has since expanded its role outside this setting and currently represents an invaluable tool to assess chamber sizes, ventricular hypertrophy, and systolic, diastolic, and valvular function in patients undergoing orthotopic liver transplantation (OLT). Right-sided microemboli, right ventricular dysfunction, and patent foramen ovale (PFO) are the most common intra-operative findings described during OLT. However, left ventricular outflow tract obstruction and left ventricular ballooning syndrome are more difficult to recognize and less frequent. Transesophageal ultrasonography (TEU) during OLT is also underused. Its applications are as follows: (1) assistance in the difficult placement of pulmonary arterial catheters; (2) help with catheterization of great vessels for external veno-venous bypass placement; (3) intra-operative evaluation of surgical liver anastomosis patency, if feasible, through the liver window; and (4) intra-operative investigation of "acute hypoxemia" due to pulmonary and cardiac issues using trans-esophageal lung ultrasound (TELU). The aims of this review are as follows: (1) to summarize the uses of TEE and TEU throughout all phases of OLT, and (2) to describe other new feasible applications.

A Comprehensive Review of Transesophageal Echocardiography During Orthotopic Liver Transplantation

Orthotopic liver transplantation (OLT) is characterized by significant hemodynamic disturbances and anesthetic challenges. Intraoperative transesophageal echocardiography (TEE) can be used to guide management during these procedures. This review examines the role of echocardiography during OLT, presents common TEE findings during each phase of OLT, and discusses the benefits demonstrated with TEE use and the safety of TEE in this patient population. Finally, the authors propose an algorithm for the safe use of TEE during OLT.

Transoesophageal echocardiography during orthotopic liver transplantation

Despite the importance of haemodynamic management in patients undergoing liver transplantation, there is currently no consensus on the most appropriate type of monitoring to use. In this context, transoesophageal echocardiography can provide useful information to professionals, although their use constraints prevent further spread today.

Anesthesia for Liver Transplantation

The provision of anesthesia for a liver transplant program requires a dedicated team of anesthesiologists. Liver transplant anesthesiologists must have an understanding of liver physiology and anatomy; the spectrum of clinical disease associated with liver dysfunction; the impact of warm and cold ischemia times, surgical techniques in liver transplantation, and the impact of ischemia-reperfusion syndrome; and optimal practices to protect the liver. The team must provide a 24-hour service, be actively involved in the selection committee process, and stay current with advances in the subspecialty.

Transoesophageal echocardiography during liver transplantation

Liver transplantation (LT) has become the standard of care for patients with end stage liver disease. The allocation of organs, which prioritizes the sickest patients, has made the management of liver transplant candidates more complex both as regards their comorbidities and their higher risk of perioperative complications. Patients undergoing LT frequently display considerable physiological changes during the procedures as a result of both the disease process and the surgery. Transoesophageal echocardiography (TEE), which visualizes dynamic cardiac function and overall contractility, has become essential for perioperative LT management and can optimize the anaesthetic management of these highly complex patients. Moreover, TEE can provide useful information on volume status and the adequacy of therapeutic interventions and can diagnose early intraoperative complications, such as the embolization of large vessels or development of pulmonary hypertension. In this review, directed at clinicians who manage TEE during LT, we show why the procedure merits a place in challenging anaesthetic environment and how it can provide essential information in the perioperative management of compromised patients undergoing this very complex surgical procedure.

The safety of transesophageal echocardiography in patients undergoing orthotopic liver transplantation

OBJECTIVE

To evaluate the safety of transesophageal echocardiography for the evaluation and intraoperative monitoring of patients during orthotopic liver transplantation.

DESIGN

Retrospective observational study.

SETTING

Tertiary care, university teaching hospital.

PARTICIPANTS

Patients (n = 116) who underwent intraoperative transesophageal echocardiography during liver transplantation.

INTERVENTIONS

Intraoperative transesophageal echocardiography during liver transplantation.

MEASUREMENTS AND MAIN RESULTS

The authors evaluated the safety of intraoperative transesophageal echocardiography in patients undergoing liver transplantation through a retrospective chart review. Complications associated with transesophageal echocardiography use were divided into minor and major complications. Out of 116 patients who underwent intraoperative transesophageal echocardiography, there was one minor and one major complication. The major complication rate was 0.86% (1/116) and the overall complication rate was 1.7% (2/116). There was no statistically significant correlation between pre-transplant sclerotherapy for treatment of varices and intraoperative transesophageal echocardiography-related gastrointestinal bleeding. Although the reported complication rate is higher than what has been quoted in the cardiac literature, intraoperative transesophageal echocardiography during liver transplantation has a low complication rate.

CONCLUSIONS

Intraoperative transesophageal echocardiography is a relatively safe method of monitoring cardiac performance in liver transplant patients.

The year in cardiothoracic and vascular anesthesia: selected highlights from 2013

This article reviewed selected research highlights of 2013 that pertain to the specialty of cardiothoracic and vascular anesthesia. The first major theme is the commemoration of the sixtieth anniversary of the first successful cardiac surgical procedure with cardiopulmonary bypass conducted by Dr Gibbon. This major milestone revolutionized the practice of cardiovascular surgery and invigorated a paradigm of mechanical platforms for contemporary perioperative cardiovascular practice. Dr Kolff was also a leading contributor in this area because of his important contributions to the refinement of cardiopulmonary bypass and mechanical ventricular assistance. The second major theme is the diffusion of echocardiography throughout perioperative practice. There are now guidelines and training pathways to guide its generalization into everyday practice. The third major theme is the paradigm shift in perioperative fluid management. Recent large randomized trials suggest that fluids are drugs that require a precise prescription with respect to type, dose, and duration. The final theme is patient safety in the cardiac perioperative environment. A recent expert scientific statement has focused attention on this issue because most perioperative errors are preventable. It is likely that clinical research in this area will blossom because this is a major opportunity for improvement in our specialty. The patient care processes identified in these research highlights will further improve perioperative outcomes for our patients.