Liver resection is a major surgery that can be associated with significant intraoperative blood loss and blood transfusion. Among high-volume centers, median intraoperative blood loss ranges between 300-800 ml. Excessive blood loss is a strong independent predictor of worsened postoperative outcomes, increasing morbidity and mortality rates by 20%-35%. Additionally, perioperative allogeneic blood transfusions are associated with deleterious outcomes, including tumor recurrence and increased rates of complications and death.
The liver is a highly vascular organ with minimal vascular resistance, receiving up to 25% of cardiac output and pooling 20% of the splanchnic blood. Hepatic veins are a common source of venous hemorrhage. The pressure in the hepatic veins is directly correlated with the pressure in the vena cava and reducing cardiac preload results in decreased hepatic vein congestion. Therefore, low central venous pressure anesthesia (typically below 5 mmHg) can reduce the pressure gradient for retrograde venous bleeding, facilitate the outflow of blood from hepatic veins, and decrease blood volume and pressure in the liver. This anesthetic method is the standard technique to minimize blood loss during liver resection.
Central venous pressure was the static parameter used to indicate the right ventricular end-diastolic volume index (RVEDI) and was believed to be correlated with volume status. Despite this, central venous pressure did not reliably predict preload responsiveness due to the curvilinear shape of the ventricular pressure-volume curve, which indicates a poor relationship between ventricular filling pressure and volume. Additionally, the placement of a central venous catheter could lead to serious complications such as arterial cannulation, pneumothorax, and infection.
Arterial waveform analysis is dynamic hemodynamic monitoring based on the interaction between the heart and lungs in patients with mechanical ventilation. Stroke volume variation (SVV) is one aspect of arterial pressure waveform analysis and is a less invasive alternative technique for guiding preload status and fluid management in patients undergoing major abdominal surgery.
In liver resection, several anesthetic methods are used to achieve low central venous pressure (CVP \< 5 mmHg) during the liver parenchymal dissection phase. These methods include intraoperative volume restriction, administration of venodilators or vasodilators, the use of forced diuresis with furosemide, and the implementation of hypovolemic phlebotomy. As mentioned, central venous pressure is a static hemodynamic monitoring parameter and poorly correlates with volume status. Recently, stroke volume variation has been recognized as a good parameter to predict volume status and fluid responsiveness in patients undergoing liver resection. However, no previous publications have studied the efficacy of stroke volume variation monitoring compared with central venous pressure monitoring to reduce perioperative blood loss during open liver resection.
The study aimed to compare the efficacy of maintaining high stroke volume variation versus low central venous pressure in reducing perioperative blood loss during the liver transection phase in open liver resection.
All genders, age 18 to 70 years old
American Society of Anesthesiologists (ASA) physical status classification of I-III
The patients who scheduled in elective open liver resection and diagnosed Hepatocellular Carcinoma, Cholangiocarcinoma, Liver metastasis, and Benign malignant tumor.
Pregnancy
Active cardiac conditions (unstable coronary syndromes, decompensated heart failure, significant arrhythmias, severe valvular disease, active coronary artery disease within 6 months prior surgery)
History of significant cerebrovascular disease (Patients with clinically significant stroke/CVA within 6 months prior surgery, severe carotid stenosis)
Renal dysfunction (GFR < 60 ml/min/1.73 m²)
Parallel
High stroke volume variation group
DeviceAnesthesiologists will perform methods to achieve and maintain SVV at 13-20% during liver parenchymal transection (fluid restrictive phase). Central venous pressure monitoring will be concealed with drapes, and the room anesthesiologist will use SVV for guiding fluid management only during parenchymal transection phase. If SVV exceeds 20%, a balanced salt crystalloid will be administered in the minimal amount necessary to reduce the SVV to below 20%.
Intraoperative blood loss during parenchymal transection phase and entire operation
To compare intraoperative blood loss between patients maintained with high stroke volume variation and those maintained with low central venous pressure during open liver resection by assessing: * Blood loss during the liver transection phase * Total blood loss Intraoperative blood loss will be estimated by combining the measured volume of suctioned blood and the measured weight of sponges and gauzes.
Allogenic blood transfusion and postoperative morbidity and mortality rate
Secondary objectives To compare 1. Intraoperative transfusion * Intraoperative allogeneic packed red cell transfusion during the operation. * Intraoperative blood product transfusion during the operation. 2. Postoperative transfusion within 72 hours * Postoperative allogeneic packed red cell transfusion during admission, excluding the operating room. * Postoperative blood product transfusion during admission, excluding the operating room. 3. Surgical field bleeding \- Classified by the same surgical team using the bleeding score of the hepatic surgical field. 4. Postoperative Major Complications \- Identified and graded by the Clavien-Dindo classification. 5. Postoperative Acute Kidney Injury \- Assessed and staged for severity according to Kidney Disease Improving Global Outcomes Outcomes (KDIGO) Clinical Practice Guidelines 6. Post-hepatectomy liver failure 7. Serum Lactate Level * Before liver resection * After completion of liver resection * After fluid resuscitation 8. Reoperation
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Warangkana Lapisatepun
Lead sponsor
Chiang Mai University
Sponsor institution
Chiang Mai University
Collaborator
