Portal Vein Embolization Using N-Butyl Cyanoacrylate-Glue: What Impact Does a Central Vascular Plug Have?

Central vascular plug-assisted portal vein embolization with absolute ethanol

AIM

Compare the efficacy and procedural efficiency of central vascular plug-assisted portal vein embolization (PVE) with absolute ethanol compared to selective PVE.

MATERIALS AND METHODS

Between 2016 and 2023, patients who underwent ipsilateral percutaneous transhepatic PVE were included. Selective PVE involves serial cannulation and embolization of portal veins. Central vascular plug-assisted PVE involves deploying a vascular plug at the main portal vein with embolization. Recorded data includes patient demographics, disease diagnosis, volumetry, embolization procedure, biliary drainage, surgery, and measures of future liver remnant hypertrophy (relative hypertrophy, degree of hypertrophy, and kinetic growth rate).

RESULTS

The cohort comprised of 30 patients (cohort mean age 64±9 years old, females n=14) of which 17 (57%) patients underwent central vascular plug-assisted PVE. Indications for PVE were predominately (87%, 26/30) due to bile duct cancer. Volumetric changes between central vascular plug-assisted PVE and selective PVE were not different between the two groups (DH 13%±5 vs 11%±4, p=0.21; and KGR 3%/week ± 2 vs 2%/week ± 2, p=0.27, respectively). Overall procedure times were shorter for central vascular plug-assisted PVE (45±20 minutes vs 112±34 minutes; p<0.001). Two adverse events occurred in selective PVE, while none in central vascular plug-assisted PVE. There was no difference in rates of surgery or no surgery for both methods (p=0.07).

CONCLUSION

Central vascular plug-assisted PVE with absolute ethanol effectively induced FLR hypertrophy, and significantly reduced procedure times due to faster embolization and simpler technique.

Liver Vein Deprivation versus Portal Vein Embolization: Retrospective Review of Safety and Effectiveness

PURPOSE

To compare the safety and effectiveness of liver vein deprivation (LVD) and portal vein embolization (PVE) in patients scheduled to undergo liver resection.

MATERIALS AND METHODS

This retrospective cohort study included 59 patients who underwent either PVE (n = 28) or LVD (n = 31) in preparation for liver resection. The primary outcome was percent change in future liver remnant volume (FLRV). The secondary endpoints were degree of hypertrophy (DH) and kinetic growth rate (KGR).

RESULTS

Low baseline FLRV and time interval in days between the procedure and follow-up imaging (Ti) positively impacted the primary and secondary endpoints in both groups. Percent change in FLRV was higher in the LVD group (52.8% ± 5.3) than in the PVE group (22.3% ± 3.0, P < .001). DH was also higher in the LVD group (15.4% ± 1.7) than in the PVE group (6.4% ± 0.9, P < .001). KGR did not differ significantly between groups (LVD, 0.54%/d ± 0.06; PVE, 0.35%/d ± 0.1; P = .239). When patients with a baseline standardized FLRV of >35% were excluded from the analysis, the LVD group demonstrated higher values than the PVE group in KGR (0.57%/d ± 0.06 vs 0.29%/d ± 0.05, P < .001), percent change in FLRV (64.2% ± 6.0 vs 25.9% ± 4.3, P < .001), and DH (15.4% ± 1.4 vs 6.6% ± 1.0, P < .001). No adverse events were noted in either group.

CONCLUSIONS

LVD appears to be safe and may be superior to PVE in inducing hypertrophy of future liver remnant in patients scheduled to undergo surgical resection.

Transfemoral hepatic vein access in double vein embolization - initial experience and feasibility

BACKGROUND

Hepatic vein embolization in double vein embolization (DVE) can be performed with transhepatic, transjugular or transfemoral access. This study evaluates the feasibility and technical success of using a transfemoral access for the hepatic vein embolization in patients undergoing preoperative to induce hypertrophy of the future liver remnant (FLR).

MATERIAL AND METHODS

Retrospective analysis of single center cohort including 17 consecutive patients. The baseline standardized FLR was 18.2% (range 14.7-24.9). Portal vein embolization was performed with vascular plugs and glue through an ipsilateral transhepatic access. Hepatic vein embolization was performed using vascular plugs. Access for the hepatic vein was either transhepatic, transjugular or transfemoral. Technical success, number of hepatic veins embolized and complications were registered. In addition, volumetric data including degree of hypertrophy (DH) and kinetic growth rate (KGR), and resection data were registered. R: Seven of the 17 patients had transfemoral hepatic vein embolization, with 100% technical success. No severe complications were registered. In the whole cohort, the median number of hepatic veins embolized was 2 (1-6). DH was 8.6% (3.0-19.4) and KGR was 3.6%/week (1.4-7.4), without significant differences between the patients having transfemoral versus transhepatic /transjugular access (p = 0.48 and 0.54 respectively). Time from DVE to surgery was median 4.8 weeks (2.6-33.9) for the whole cohort, with one patient declining surgery, two having explorative laparotomy and one patient having change of surgical strategy due to insufficient growth.

CONCLUSION

Transfemoral access is a feasible option with a high degree of technical success for hepatic vein embolization in patients with small future liver remnants needing DVE.

CIRSE Standards of Practice on Portal Vein Embolization and Double Vein Embolization/Liver Venous Deprivation

This CIRSE Standards of Practice document is aimed at interventional radiologists and provides best practices for performing liver regeneration therapies prior to major hepatectomies, including portal vein embolization, double vein embolization and liver venous deprivation. It has been developed by an expert writing group under the guidance of the CIRSE Standards of Practice Committee. It encompasses all clinical and technical details required to perform liver regeneration therapies, revising the indications, contra-indications, outcome measures assessed, technique and expected outcomes.

Balloon-Assisted Portal Vein Embolization Using n-Butyl-2-Cyanoacrylate-Lipiodol-Iopamidol Mixture in Swine: A Comparison of 2 Formulations

PURPOSE

To compare 2 ratios of n-butyl-2-cyanoacrylate (nBCA)-ethiodized oil (Lipiodol)-iopamidol (NLI) in balloon-assisted portal vein embolization (PVE) in swine.

MATERIALS AND METHODS

In an in vitro study, NLI prepared at a ratio of 2:3:1 (NLI231) or 1:4:1 (NLI141) was injected into 2.5- or 10-mL syringes filled with swine blood, and the viscosity of NLI was measured to determine an appropriate balloon occlusion time. Two portal vein branches in 8 female swine (n = 16 vein branches) were embolized with NLI231 (n = 8) or NLI141 (n = 8) under balloon occlusion. Portal venography was performed before, immediately after, and 3 days after PVE to evaluate the migration of NLI and the recanalization of embolized portal vein branches. Then, the livers were removed for histopathologic evaluation.

RESULTS

The times to peak viscosity of NLI231 in the 2.5- and 10-mL syringes were 55.8 seconds (SD ± 7.0) and 85.2 seconds (SD ± 6.3), and those to peak viscosity of NLI141 were 129.2 seconds (SD ± 11.8) and 254.0 seconds (SD ± 21.8), respectively. No migration of NLI231 was observed in all 8 procedures immediately or 3 days after PVE. Migration of NLI141 was observed in 6 of 8 procedures within 3 days after PVE. The migration frequency of the embolic material was lower in the NI231 group than in the NLI141 group (0/8 vs 6/8; P = .051). Histologically, NLI231 occupied the portal veins without any thrombi, whereas NLI141 was accompanied by thrombi in the portal veins.

CONCLUSIONS

NLI231 may be more suitable than NLI141 for balloon-assisted PVE in swine.

Portal vein embolization with N-butyl-cyanoacrylate improves liver hypertrophy compared to microparticles - A Swedish multicenter cohort study

Background

An adequate future liver remnant (FLR) is fundamental for major liver resections. To achieve sufficient FLR, portal vein embolization (PVE) may be used. The most effective material for PVE has yet to be determined. The aim of this study was to investigate the differences in FLR growth between n-butyl-cyanoacrylate glue (NBCA) and microparticles.

Material/methodsa

retrospective study was performed at three Swedish hepatobiliary centers and included patients who underwent PVE 2013-2021. Electronic medical records were reviewed, and procedure-related data were collected. Data were analyzed with respect to embolizing material.

Results

A total of 265 patients were included: 160 in the NBCA group and 105 in the microparticle group. The NBCA group had a higher degree of hypertrophy (12.1 vs. 9.4 % points, p = 0.003) and a higher resection rate (68 vs. 59 %, p = 0.01) than the microparticle group. Procedure-related data all indicated the superiority of NBCA. No difference in inducing hypertrophy was observed when comparing patients who received chemotherapy before PVE with those who received chemotherapy before and after PVE within the NBCA group.

Discussion/conclusion

This retrospective multicenter study supports the superiority of NBCA compared to microparticles in the setting of PVE. Chemotherapy after PVE does not seem to negatively affect hypertrophy.

Sodium Phytate-Incorporated Gelatin-Silicate Nanoplatelet Composites for Enhanced Cohesion and Hemostatic Function of Shear-Thinning Biomaterials

Shear-thinning biomaterials (STBs) based on gelatin-silicate nanoplatelets (SNs) are emerging as an alternative to conventional coiling and clipping techniques in the treatment of vascular anomalies. Improvements in the cohesion of STB hydrogels pave the way toward their translational application in minimally invasive therapies such as endovascular embolization repair. In the present study, sodium phytate (Phyt) additives are used to tune the electrostatic network of SNs-gelatin STBs, thereby promoting their mechanical integrity and facilitating injectability through standard catheters. We show that an optimized amount of Phyt enhances storage modulus by approximately one order of magnitude and reduces injection force by ≈58% without compromising biocompatibility and hydrogel wet stability. The Phyt additives are found to decrease the immune responses induced by SNs. In vitro embolization experiments suggest a significantly lower rate of failure in Phyt-incorporated STBs than in control groups. Furthermore, the addition of Phyt leads to accelerated blood coagulation (reduces clotting time by ≈45% compared to controls) due to the contributions of negatively charged phosphate groups, which aid in the prolonged durability of STB in coagulopathic patients. Therefore, the proposed approach is an effective method for the design of robust and injectable STBs for minimally invasive treatment of vascular malformations.

Portal vein embolization versus dual vein embolization for management of the future liver remnant in patients undergoing major hepatectomy: meta-analysis

BACKGROUND

This meta-analysis aimed to compare progression to surgery, extent of liver hypertrophy, and postoperative outcomes in patients planned for major hepatectomy following either portal vein embolization (PVE) or dual vein embolization (DVE) for management of an inadequate future liver remnant (FLR).

METHODS

An electronic search was performed of MEDLINE, Embase, and PubMed databases using both medical subject headings (MeSH) and truncated word searches. Articles comparing PVE with DVE up to January 2022 were included. Articles comparing sequential DVE were excluded. ORs, risk ratios, and mean difference (MD) were calculated using fixed and random-effects models for meta-analysis.

RESULTS

Eight retrospective studies including 523 patients were included in the study. Baseline characteristics between the groups, specifically, age, sex, BMI, indication for resection, and baseline FLR (ml and per cent) were comparable. The percentage increase in hypertrophy was larger in the DVE group, 66 per cent in the DVE group versus 27 per cent in the PVE group, MD 39.07 (9.09, 69.05) (P = 0.010). Significantly fewer patients failed to progress to surgery in the DVE group than the PVE group, 13 per cent versus 25 per cent respectively OR 0.53 (0.31, 0.90) (P = 0.020). Rates of post-hepatectomy liver failure 13 per cent versus 22 per cent (P = 0.130) and major complications 20 per cent versus 28 per cent (Clavien-Dindo more than IIIa) (P = 0.280) were lower. Perioperative mortality was lower with DVE, 1 per cent versus 10 per cent (P = 0.010).

CONCLUSION

DVE seems to produce a greater degree of hypertrophy of the FLR than PVE alone which translates into more patients progressing to surgery. Higher quality studies are needed to confirm these results.