Assessment of Liver Stiffness Measurement: Novel Intraoperative Blood Loss Predictor?

Perioperative outcomes of utilizing infrahepatic inferior vena cava clamping and Pringle maneuver during hepatectomy: a meta-analysis

PURPOSE

Intraoperative bleeding during hepatectomy is primarily controlled through anaesthesiological interventions or surgical techniques such as Pringle maneuver (PM). Infrahepatic IVC clamping (IIVCC) is an alternative surgical technique to reduce central venous pressure and prevent retrograde hepatic venous bleeding. The aim of the meta-analysis was to compare IIVCC+PM with PM alone in terms of intraoperative outcomes and perioperative complications.

METHODS

Medline, Cochrane Library, Scopus, Web of Science, and EMBASE were searched for comparative studies till 16.04.2024, resulting in 679 articles, of which eight studies met inclusion criteria. Data on patient demographics, surgical technique, and perioperative outcomes was assessed. Cochrane Risk of Bias 2.0 (RoB 2.0) Tool and Newcastle-Ottawa Scale (NOS) were used for risk of bias assessment.

RESULTS

Two randomized controlled trials, one prospective, and five retrospective cohort studies with 358 patients in IIVCC+PM and 397 patients in PM alone group were included. IIVCC+PM resulted in significantly greater CVP reduction, less intraoperative blood loss (MD (95% CI) = - 233.03 (- 360.48 to - 105.58), P < 0.001), and less intraoperative blood transfusion (OR (95% CI) = 0.38 (0.25 to 0.57), P < 0.001) compared to PM alone. The two groups had comparable total operative time, transection time and total intraoperative fluid infusion. Patients undergoing IIVCC+PM had significantly shorter length of stay (MD (95% CI) = - 0.63 days (- 1.21 to - 0.05 days), P = 0.03) and overall complication rates (OR (95% CI) = 0.63 (0.43-0.92), P = 0.02) compared to PM alone group.

CONCLUSION

The utilization of IIVCC along with PM during liver resection may be beneficial in reducing intraoperative bleeding and blood transfusion without adversely influencing operative times or perioperative outcomes compared to PM alone.

Established and potential predictors of blood loss during lung transplant surgery

Lung transplantation is an established therapeutic procedure for end stage lung diseases. Its success may be impaired by perioperative complications. Intraoperative blood loss and the resulting blood transfusion are among the most common complications. The various factors contributing to increased blood loss during lung transplantation are only scarcely investigated and not yet completely understood. This is in sharp contrast to other surgical fields, as in orthopedic surgery, liver transplantation and cardiac surgery the contributors to blood loss are well identified. This narrative review article aims to highlight the acknowledged factors influencing blood loss in lung transplantation (such as double vs. single lung transplant) and to discuss potential factors that may be of interest for further research or helpful to develop strategies targeting risk factors in order to minimize blood loss during lung transplantation and finally improve patient outcome.

Prediction of major complications after hepatectomy using liver stiffness values determined by magnetic resonance elastography

BACKGROUND

Liver fibrosis is a risk factor for hepatectomy but cannot be determined accurately before hepatectomy because diagnostic procedures are too invasive. Magnetic resonance elastography (MRE) can determine liver stiffness (LS), a surrogate marker for assessing liver fibrosis, non-invasively. The aim of this study was to investigate whether the LS value determined by MRE is predictive of major complications after hepatectomy.

METHODS

This prospective study enrolled consecutive patients who underwent hepatic resection between April 2013 and August 2016. LS values were measured by imaging shear waves by MRE in the liver before hepatectomy. The primary endpoint was major complications, defined as Clavien-Dindo grade IIIa or above. Logistic regression analysis identified independent predictive factors, from which a logistic model to estimate the probability of major complications was constructed.

RESULTS

A total of 96 patients were included in the study. Major complications were observed in 15 patients (16 per cent). Multivariable logistic analysis confirmed that higher LS value (P = 0·021) and serum albumin level (P = 0·009) were independent predictive factors for major complications after hepatectomy. Receiver operating characteristic (ROC) analysis showed that the best LS cut-off value was 4·3 kPa for detecting major complications, comparable to liver fibrosis grade F4, with a sensitivity of 80 per cent and specificity of 82 per cent. A logistic model using the LS value and serum albumin level to estimate the probability of major complications was constructed; the area under the ROC curve for predicting major complications was 0·84.

CONCLUSION

The LS value determined by MRE in patients undergoing hepatectomy was an independent predictive factor for major complications.

A prediction model for the grade of liver fibrosis using magnetic resonance elastography

BACKGROUND

Liver stiffness measurement (LSM) has recently become available for assessment of liver fibrosis. We aimed to develop a prediction model for liver fibrosis using clinical variables, including LSM.

METHODS

We performed a prospective study to compare liver fibrosis grade with fibrosis score. LSM was measured using magnetic resonance elastography in 184 patients that underwent liver resection, and liver fibrosis grade was diagnosed histologically after surgery. Using the prediction model established in the training group, we validated the classification accuracy in the independent test group.

RESULTS

First, we determined a cut-off value for stratifying fibrosis grade using LSM in 122 patients in the training group, and correctly diagnosed fibrosis grades of 62 patients in the test group with a total accuracy of 69.3%. Next, on least absolute shrinkage and selection operator analysis in the training group, LSM (r = 0.687, P < 0.001), indocyanine green clearance rate at 15 min (ICGR15) (r = 0.527, P < 0.001), platelet count (r = -0.537, P < 0.001) were selected as variables for the liver fibrosis prediction model. This prediction model applied to the test group correctly diagnosed 32 of 36 (88.8%) Grade I (F0 and F1) patients, 13 of 18 (72.2%) Grade II (F2 and F3) patients, and 7 of 8 (87.5%) Grade III (F4) patients in the test group, with a total accuracy of 83.8%.

CONCLUSIONS

The prediction model based on LSM, ICGR15, and platelet count can accurately and reproducibly predict liver fibrosis grade.

Predicting postoperative outcomes of liver resection by magnetic resonance elastography

BACKGROUND

Cirrhosis is associated with blood loss during liver resection and postoperative complications. The liver stiffness measurement has recently become available for assessment of liver fibrosis.

METHODS

This prospective study was performed to predict postoperative outcomes of liver resection. The liver stiffness measurement was measured prospectively using magnetic resonance elastography for patients who had undergone liver resection for malignancy. We investigated whether the liver stiffness measurement by magnetic resonance elastography is correlated with liver fibrosis and postoperative outcomes.

RESULTS

The median liver stiffness measurement by magnetic resonance elastography in 175 patients was 3.4 (range: 1.5-11.3) kPa, and the pathologic grade of liver fibrosis was significantly correlated with the liver stiffness measurement (r = 0.68, P < .001). The median blood loss during transection per unit area was 4.1 mL/cm² (range: 0.1-37.0 mL/cm²), and the frequency of major complications was 16.0%. The liver stiffness measurement was the only independent prognostic factor for both blood loss (regression coefficient: 1.14, 95% confidence interval: 0.45-1.83, P = .001) and major complications (odds ratio: 2.14, 95% confidence interval: 1.63-2.93, P < .001). Receiver operating characteristic curve analysis indicated a significant correlation between the liver stiffness measurement and major complications with calculated area under the curve of 0.81 (P < .001), and the sensitivity and specificity for prediction of major complications (cutoff value: 5.3 kPa) were 64.3% and 87.8%, respectively. On the other hand, the amount of blood loss was significantly correlated with the frequency of major complications (P = .003).

CONCLUSION

The liver stiffness measurement by magnetic resonance elastography could be used as a predictive marker for the risk of major complications due to blood loss during liver resection.