# Anesthesia Experience With Aortic Valve Replacement Guided by Blood Viscoelasticity Testing in a Late Post-Fontan Patient: A Case Report

## TL;DR

This case report describes the use of blood viscoelasticity testing to guide anesthesia and coagulation management during aortic valve replacement in a high-risk post-Fontan patient.

## Contribution

The report highlights the utility of viscoelasticity testing in identifying functional fibrinogen abnormalities in post-Fontan patients undergoing complex cardiac surgery.

## Key findings

- Blood viscoelasticity testing revealed severe preoperative fibrinogen dysfunction that worsened after cardiopulmonary bypass.
- A discrepancy was found between viscoelasticity test results and Clauss assay fibrinogen levels, indicating a qualitative fibrinogen abnormality.
- Fibrinogen concentrate administration, guided by viscoelasticity testing, effectively treated the coagulopathy.

## Abstract

Coagulation management poses a challenge for post-Fontan patients requiring anesthesia for aortic valve replacement (AVR). This is because post-Fontan patients have a history of multiple sternotomies and resultant strong adhesions, in addition to being potentially deficient in coagulation factors, as observed in several post-Fontan patients. Moreover, coagulation factors are further diluted and consumed during cardiopulmonary bypass (CPB). In this report, we present the anesthetic management during AVR in a post-Fontan patient. A 32-year-old post-Fontan female patient underwent valve replacement for stenosis and regurgitation of the aortic valve. She had a history of multiple thoracotomies and was considered to be at high risk for hemorrhage, based on the assumption that she had extensive and robust adhesions, which were confirmed intraoperatively. Blood viscoelasticity tests were performed preoperatively and after weaning from the CPB to evaluate coagulation factor deficiency. Severe preoperative fibrinogen dysfunction was observed, which was exacerbated after CPB. A marked discrepancy also existed between the results of blood viscoelasticity testing and fibrinogen levels obtained using the Clauss assay. We concluded that the patient exhibited a qualitative functional abnormality of fibrinogen itself, rather than a decrease in fibrinogen concentration. Based on the viscoelasticity tests and clinical hemostatic status, fibrinogen concentrate was administered to treat the hypofibrinogenic state. Evaluation of fibrinogen function using blood viscoelasticity tests was useful in identifying the cause and the treatment of coagulopathy after CPB in our patient.