Relationship between hemodynamic parameters and portal venous pressure in cirrhosis patients with portal hypertension

A compact machine perfusion device for whole blood perfusion in isolated rat liver

We established a compact machine perfusion system for whole blood perfusion of rat liver by making use of oxygenation filters as an artificial lung. Livers removed from rats were divided into Krebs-Henseleit (control), 50% blood (hemoglobin: 7 g/dL), and whole blood (hemoglobin: 14 g/dL) groups, then perfused (total perfusate volume: 25 ml) with a small oxygenation filter at 37 °C for 120 min. Blood or perfusate was collected over time, and blood gas and blood cell were measured. In addition, bile volume and portal venous pressure measurements were taken. In all groups, the partial pressure of oxygen was controlled to approximately 400 mmHg. Flow rates were maintained at approximately about 20-30 ml/min according to liver size. Portal venous pressure was normal in the 50% blood and whole blood groups, while lower than the reference value in the Krebs-Henseleit group. Twice as much bile was produced in the 50% blood and whole blood groups relative with the Krebs-Henseleit group. We observed no differences in hemoglobin and red blood cell levels. Lactate levels were normal in the 50% blood and whole blood groups, but were elevated in the Krebs-Henseleit group. Our compact perfusion system using oxygenation filters was able to maintain rat liver function by perfusing a small amount of extracorporeal blood. This system is simple and stable, and may contribute to the future development of machine perfusion systems.

Does portal vein anatomy influence intrahepatic distribution of metastases from colorectal cancer?

BACKGROUND

Other than location of the primary colorectal cancer (CRC), a few factors are known to influence the intrahepatic distribution of colorectal cancer liver metastases (CRLM). We aimed to assess whether the anatomy of the portal vein (PV) could influence the intrahepatic distribution of CRLM.

PATIENTS AND METHODS

Patients with CRLM diagnosed between January 2018 and December 2022 at two tertiary centers were included and imaging was reviewed by two radiologists independently. Intra-operator concordance was assessed according to the intraclass correlation coefficient (ICC). The influence of the diameter, angulation of the PV branches and their variations on the number and distribution of CRLM were compared using Mann-Whitney, Kruskal-Wallis, Pearson's Chi-square and Spearman's correlation tests.

RESULTS

Two hundred patients were included. ICC was high (> 0.90, P < 0.001). Intrahepatic CRLM distribution was right-liver, left-liver unilateral and bilateral in 66 (33%), 24 (12%) and 110 patients (55%), respectively. Median number of CRLM was 3 (1-7). Type 1, 2 and 3 portal vein variations were observed in 156 (78%), 19 (9.5%) and 25 (12%) patients, respectively. CRLM unilateral or bilateral distribution was not influenced by PV anatomical variations (P = 0.13), diameter of the right (P = 0.90) or left (P = 0.50) PV branches, angulation of the right (P = 0.20) or left (P = 0.80) PV branches and was independent from primary tumor localisation (P = 0.60). No correlations were found between CRLM number and diameter (R: 0.093, P = 0.10) or angulation of the PV branches (R: 0.012, P = 0.83).

CONCLUSIONS

PV anatomy does not seem to influence the distribution and number of CRLM.

Analysis of transjugular intrahepatic portosystemic shunt by hemodynamic simulation

BACKGROUND

Transjugular intrahepatic portosystemic shunt (TIPS), which artificially creates a portocaval shunt to reduce portal venous pressure, has gradually become the primary treatment for portal hypertension (PH). However, there is no prefect shunting scheme in TIPS to balance the occurrence of postoperative complications and effective haemostasis.

OBJECTIVE

To construct cirrhotic PH models and compare different shunting schemes in TIPS.

METHODS

Three cases of cirrhotic PH with different liver volumes were selected for enhanced computed tomography scanning. The models for different shunting schemes were created using Mimics software, and following FLUENT calculation, all the models were imported into the software computational fluid dynamic-post for processing. In each shunting scheme, the differences in portal vein pressure, hepatic blood perfusion and blood flow from the superior mesenteric vein in the shunt tract were compared. The coefficient G was adapted to evaluate the advantages and disadvantages.

RESULTS

(1) Concerning the precise location of the shunt tract, the wider the diameter of the shunt tract, the lower the pressure of the portal vein and the lesser the hepatic blood perfusion. Meanwhile, the pressure drop objective was not achieved with the 6 mm-diameter shunting scheme. (2) The 8 mm-diameter shunting scheme through the left portal vein (LPV) had the highest coefficient G.

CONCLUSION

The 8 mm-diameter shunting scheme through the LPV may demonstrate a superior effect and prognosis in TIPS procedures.

Development of a Direct Non-Puncture Device for Measuring Portal Venous Pressure during Liver Transplantation-A Swine Model

Portal hypertension-related complications pose a significant risk for liver failure post-transplantation. Thus, accurate monitoring of intraoperative portal venous pressure (PVP) is crucial. However, current PVP monitoring techniques requiring direct percutaneous puncture carry the risk of graft damage. In this study, we present an innovative non-puncture PVP monitoring device (PVPMD) using a 3D-printed prototype. PVPMD design is inspired by the sphygmomanometer principle, and strategically encompasses the portal vein and enables precise PVP measurement through blood flow ultrasonography after temporary occlusion. By a series of mini-pig experiments, the prototype PVPMD demonstrated a strong correlation with invasive catheter measurements in the main trunk of the portal vein (rs = 0.923, p = 0.000). There was a significant repeatability and reproducibility between the prototype PVPMD- and invasive catheter-measured PVP. This indicates that the PVPMD holds immense potential for direct application in liver transplantation and surgery. Moreover, it has the potential to replace catheter-based central venous pressure (CVP) measurements, thereby mitigating catheter-related complications during many surgeries. In conclusion, our innovative device represents a significant advancement in PVP monitoring during liver transplantation, with comprehensive validation from principle exploration to successful animal experiments. We anticipate that this groundbreaking PVPMD will attract the attention of researchers and clinicians, propelling the noninvasive measurement of PVP or other venous/arterial pressures into a new era of clinical practice.

Carvedilol Versus Other Nonselective Beta Blockers for Variceal Bleeding Prophylaxis and Death: A Network Meta-analysis

Background and Aims

We aimed to perform a network meta-analysis (NWM) to examine comparative effectiveness of non-selective beta blockers (NSBBs) on prophylaxis of gastroesophageal variceal bleeding (GVB) and mortality benefit.

Methods

MEDLINE (OVID) and EMBASE databases were searched for eligible randomized clinical trials (RCTs) from inception to July 3, 2021. Outcomes of interest included primary/secondary prophylaxis of GVB, failure to achieve hepatic venous pressure gradient (HVPG) decremental response, liver-related and all-cause mortality. A Bayesian NWM was performed to derive relative risk (RR) with 95% credible intervals (CrIs). The ranking probability of each NSBB was assessed by surface under cumulative ranking curve (SUCRA).

Results

Thirty-three RCTs including 3,188 cirrhosis patients with gastroesophageal varices were included. Compared with placebo, nadolol ranked first for reducing variceal bleeding [RR:0.25, (95% CrI:0.11-0.51); SUCRA:0.898], followed by carvedilol [RR:0.33, (95% CrI: 0.11-0.88); SUCRA:0.692] and propranolol [RR:0.52, (95% CrI:0.37-0.75); SUCRA:0.405]. Carvedilol was more effective than propranolol in achieving HVPG decremental response [RR:0.43, (95% CrI: 0.26-0.69)]. Carvedilol ranked first for reducing all-cause mortality [RR: 0.32, (95% CrI:0.17-0.57); SUCRA:0.963), followed by nadolol [RR:0.48, (95% CI:0.29-0.77); SUCRA:0.688], and propranolol [RR:0.77, (95% CI:0.58-1.02); SUCRA: 0.337]. Similar findings were observed for liver-related mortality. Carvedilol ranked the safest. The RR of adverse events was 4.38, (95% CrI:0.33-161.4); SUCRA:0.530, followed by propranolol [RR: 7.54, (95% CrI:1.90-47.89); SUCRA:0.360], and nadolol [RR: 18.24, (95% CrI:91.51-390.90); SUCRA:0.158].

Conclusions

Carvedilol is the preferred NSBB with better survival benefit and lower occurrence of adverse events among patients with gastroesophageal varices.

Preventing Small-for-size Syndrome in Living Donor Liver Transplantation: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference

Small-for-size syndrome (SFSS) is a well-recognized complication following liver transplantation (LT), with up to 20% developing this following living donor LT (LDLT). Preventing SFSS involves consideration of factors before the surgical procedure, including donor and recipient selection, and factors during the surgical procedure, including adequate outflow reconstruction, graft portal inflow modulation, and management of portosystemic shunts. International Liver Transplantation Society, International Living Donor Liver Transplantation Group, and Liver Transplant Society of India Consensus Conference was convened in January 2023 to develop recommendations for the prediction and management of SFSS in LDLT. The format of the conference was based on the Grading of Recommendations, Assessment, Development, and Evaluation system. International experts in this field were allocated to 4 working groups (diagnosis, prevention, anesthesia, and critical care considerations, and management of established SFSS). The working groups prepared evidence-based recommendations to answer-specific questions considering the currently available literature. The working group members, independent panel, and conference attendees served as jury to edit and confirm the final recommendations presented at the end of the conference by each working group separately. This report presents the final statements and evidence-based recommendations provided by working group 2 that can be implemented to prevent SFSS in LDLT patients.

Adaptation of lenvatinib treatment in patients with hepatocellular carcinoma and portal vein tumor thrombosis

PURPOSE

The aim of this study was to clarify the adaptation of lenvatinib treatment in patients with hepatocellular carcinoma (HCC) and portal vein tumor thrombosis (PVTT).

METHOD

Fifty-three patients with HCC were treated with lenvatinib. Before and after treatment blood sampling, patients were examined by computed tomography and ultrasonography. In patients with portal trunk invasion (Vp4), the analysis focused on the degree of occlusion due to the tumor in the portal trunk. In patients without major PVTT {ie, invasion of the primary branch of the portal vein [Vp3] or Vp4}, portal blood flow volume was measured by Doppler analysis; however, Doppler analysis is difficult to perform in patients with major PVTT, so the time from administration of the contrast agent to when it reached the primary branch of the portal vein (portal vein arrival time) was evaluated with the contrast agent Sonazoid.

RESULTS

Patients with Vp4 had a significantly worse prognosis than patients with Vp3 and a significant increase in Child-Pugh score at 2 months. Patients with major PVTT had a poor prognosis if the degree of occlusion of the portal trunk was 70% or more. In patients without major PVTT, portal blood flow was significantly decreased after administration of lenvatinib; and in patients with major PVTT, the hepatic artery and portal vein arrival times were significantly increased.

CONCLUSION

Lenvatinib treatment should be avoided in patients with Vp4 with a high degree of portal trunk occlusion because of concerns about decreased portal blood flow.