Comparison of percutaneous transhepatic portal vein embolization and unilateral portal vein ligation

The Guidelines for Percutaneous Transhepatic Portal Vein Embolization: English Version

Preoperative portal vein embolization is a beneficial option to reduce the risk of postoperative liver failure by promoting the growth of the future liver remnant. In particular, a percutaneous transhepatic procedure (percutaneous transhepatic portal vein embolization) has been developed as a less-invasive approach. Although percutaneous transhepatic portal vein embolization is widely recognized as a safe procedure, various complications, including rare but fatal adverse events, have been reported. Currently, there are no prospective clinical trials regarding percutaneous transhepatic portal vein embolization procedures and no standard guidelines for the PTPE procedure in Japan. As a result, various methods and various embolic materials are used in each hospital according to each physician's policy. The purpose of these guidelines is to propose appropriate techniques at present and to identify issues that should be addressed in the future for safer and more reliable percutaneous transhepatic portal vein embolization techniques.

Right portal vein ligation is still relevant for left hemi-liver hypertrophy: results of a comparative study using a propensity score between right portal vein ligation and embolization

BACKGROUND

In two-stage hepatectomy for bilobar liver metastases from colorectal cancer, future liver remnant (FLR) growth can be achieved using several techniques, such as right portal vein ligation (RPVL) or right portal vein embolization (RPVE). A few heterogeneous studies have compared these two techniques with contradictory results concerning FLR growth. The objective of this study was to compare FLR hypertrophy of the left hemi-liver after RPVL and RPVE.

STUDY DESIGN

This was a retrospective comparative study using a propensity score of patients who underwent RPVL or RPVE prior to major hepatectomy between January 2010 and December 2020. The endpoints were FLR growth (%) after weighting using the propensity score, which included FLR prior to surgery and the number of chemotherapy cycles. Secondary endpoints were the percentage of patients undergoing simultaneous procedures, the morbidity and mortality, the recourse to other liver hypertrophy procedures, and the number of invasive procedures for the entire oncologic program in intention-to-treat analysis.

RESULTS

Fifty-four consecutive patients were retrospectively included and analyzed, 18 in the RPVL group, and 36 in the RPVE group. The demographic characteristics were similar between the groups. After weighting, there was no significant difference between the RPVL and RPVE groups for FLR growth (%), respectively 32.5% [19.3-56.0%] and 34.5% [20.5-47.3%] (p = 0.221). There was no significant difference regarding the secondary outcomes except for the lower number of invasive procedures in RPVL group (median of 2 [2.0, 3.0] in RPVL group and 3 [3.0, 3.0] in RPVE group, p = 0.001)).

CONCLUSION

RPVL and RPVE are both effective to provide required left hemi-liver hypertrophy before right hepatectomy. RPVL should be considered for the simultaneous treatment of liver metastases and the primary tumor.

Alcohol injection into the portal vein prior to ligation increases liver regeneration rate

BACKGROUND

Failure of portal vein ligation (PVL) to induce hypertrophy is not uncommon. The aim of the study was to evaluate the impact of intraportal alcohol injection prior to ligation on liver regeneration.

METHOD

Forty-two patients with colorectal liver metastases who underwent PVL between 01/2004 and 06/2014 were analyzed. Beginning in 09/2011, alcohol was injected prior to PVL. Patients treated with PVL alone (Alc- group) were compared with those treated with alcohol injection plus PVL (Alc+ group). Liver regeneration was assessed by volumetric increase (VI).

RESULTS

Alc+ (23 patients) and Alc- (19 patients) groups were similar in terms of age, sex and pre-PVL FLRV. Alc- group had a higher risk of recanalization (12 vs. 1, p < 0.001) and cavernous transformation (7 vs. 2, p = 0.055) of the occluded portal vein. Post-PVL FLRV (43.3 ± 14.3% vs. 34.6 ± 6.4%, p = 0.013) and VI (0.44 ± 0.24 vs. 0.28 ± 0.20, p = 0.029) were higher in Alc+ group. On multivariate analysis male sex (B = -0.149) and alcohol injection (B = 0.143) significantly predicted VI.

CONCLUSIONS

Alcohol injection prior to PVL may increase the regeneration of the FLRV by reducing the recanalization of the occluded portal vein.

Meta-analysis of associating liver partition with portal vein ligation and portal vein occlusion for two-stage hepatectomy

BACKGROUND

Discussion is ongoing regarding whether associating liver partition with portal vein ligation for staged hepatectomy (ALPPS) or portal vein occlusion is better in staged hepatectomy. The aim of this study was to compare available strategies using a two-stage approach in extended hepatectomy.

METHODS

A literature search was performed in MEDLINE, Scopus, the Cochrane Library and Embase, and additional articles were identified by hand searching. Data from the international ALPPS registry were extracted. Clinical studies reporting volumetric changes, mortality, morbidity, feasibility of the second stage and tumour-free resection margins (R0) in two-stage hepatectomy were included.

RESULTS

Ninety studies involving 4352 patients, including 320 from the ALPPS registry, met the inclusion criteria. Among these, nine studies (357 patients) reported on comparisons with other strategies. In the comparison of ALPPS versus portal vein embolization (PVE), ALPPS was associated with a greater increase in the future liver remnant (76 versus 37 per cent; P < 0·001) and more frequent completion of stage 2 (100 versus 77 per cent; P < 0·001). Compared with PVE, ALPPS had a trend towards higher morbidity (73 versus 59 per cent; P = 0·16) and mortality (14 versus 7 per cent; P = 0·19) after stage 2. In the non-comparative studies, complication rates were 39 per cent in the PVE group, 47 per cent in the portal vein ligation (PVL) group and 70 per cent in the ALPPS group. After stage 2, mortality rates were 5, 7 and 12 per cent respectively.

CONCLUSION

ALPPS is associated with greater future liver remnant hypertrophy and a higher rate of completion of stage 2, but this may be at the price of greater morbidity and mortality.

Tumour growth of colorectal rat liver metastases is inhibited by hepatic arterial infusion of the mTOR-inhibitor temsirolimus after portal branch ligation

Portal branch ligation (PBL) can be performed before major hepatic resection of colorectal liver metastases (mCRC) to increase the remnant liver mass. However, PBL may also stimulate mCRC growth through hepatic arterial hyperperfusion and growth factor release. Herein, we studied whether hepatic arterial infusion (HAI) of the mTOR-inhibitor temsirolimus (Tem) is capable of inhibiting the growth of colorectal liver metastases after PBL. WAG/Rij rats were randomized to four groups (n=6 each) and underwent subcapsular implantation of 5×10(5) CC531 cells into the left liver lobe. The animals of two groups underwent simultaneous PBL of the tumour bearing liver lobe. Ten days later animals underwent a HAI either of temsirolimus (Tem and PBL Tem) or saline solution (Sham and PBL Sham). Tumour size was analyzed at days 10 and 13 using three-dimensional ultrasound. In Sham controls tumour volume increased by 43%. After PBL Sham tumour volume increased by 52%. In contrast, in animals undergoing HAI of temsirolimus the tumour growth was not only completely inhibited, but tumour volume was found decreased, irrespective of PBL. After HAI of temsirolimus immunohistochemistry revealed an increased cleaved caspase-3 activity, indicating stimulation of apoptotic cell death. In parallel temsirolimus treatment was associated with a significant reduction of PECAM-1 positive cells within the tumour tissue, implying a reduced tumour vascularisation. HAI of temsirolimus is capable of inhibiting the growth of CC531 colorectal rat liver metastases also after PBL.

Bismuth classification is associated with the requirement for multiple biliary drainage in preoperative patients with malignant perihilar biliary stricture

BACKGROUND

Single preoperative biliary drainage for malignant perihilar biliary stricture occasionally fails to control jaundice and cholangitis. Multiple biliary drainage is required in such cases, but their clinical background is unclear. We determined the clinical characteristics associated with the requirement for multiple biliary drainage.

METHODS

The consecutive 122 patients with malignant perihilar biliary stricture were enrolled in a single-center retrospective study. Preoperative biliary drainage was initially performed on the future remnant hepatic lobe. Additional drainage was performed if jaundice failed to improve or cholangitis developed in undrained hepatic lobes. Detailed clinical characteristics and the number of preoperative biliary drainage procedures required before operation were analyzed.

RESULTS

Thirty-one patients (25.4%) initially underwent multiple biliary drainage. However, 69 (56.7%) required multiple biliary drainage by the time of the operation. In the univariate analysis, the initial serum bilirubin level, cholangitis, percutaneous portal vein embolization, history of inserted endoscopic biliary stenting, length of preoperative period, operative procedure, and Bismuth classification were significant factors. In the multivariate analysis using these factors, Bismuth classification was independently associated with the requirement for multiple biliary drainage. The number of patients who required multiple biliary drainage was higher in those with Bismuth-II (91.9%), Bismuth-IIIa (65.7%), and Bismuth-IV (92.9%) than in those with Bismuth-I (22.2%) and Bismuth-IIIb (18.2%).

CONCLUSIONS

Patients with Bismuth-II, Bismuth-IIIa, and Bismuth-IV are at higher risk for multiple biliary drainage. A strategy based on the Bismuth classification for performing preoperative biliary drainage is important for patients with malignant perihilar biliary stricture.

Is there new hope for patients with marginally resectable liver malignancies

Advances in surgical technique and better perioperative management have significantly improved patient outcomes after liver surgery. Even major hepatectomy can be performed safely with low morbidity and mortality. Post-resection liver failure is among the most feared complications after extended hepatectomy. In order to increase the future liver remnant (FLR) and to expand the pool of candidates for surgical resection, Schnitzbauer et al recently presented a new 2-stage surgical approach which combines right portal vein ligation (rPVL) with in situ splitting (ISS) of the liver parenchyma. In comparison to other current strategies, such as interventional portal vein embolization, hypertrophy of the FLR was more pronounced (median volume increase = 74%; range: 21%-192%) and more rapid (after a median of 9 d; range: 5-28 d) after rPVL and ISS. In this commentary, we discuss the technical aspects and clinical impact of rPVL combined with ISS. Based on the reported data, this new 2-stage therapeutic approach represents a promising new strategy for patients with locally advanced liver disease, previously regarded as marginally resectable or even unresectable, potentially enabling curative resection. However, morbidity is significant and mortality not negligible.