Extended right-sided liver resection for colorectal liver metastases--impact of percutaneous portal venous embolisation

Does portal vein embolization prior to liver resection influence the oncological outcomes - A propensity score matched comparison

INTRODUCTION

There is an ongoing controversy surrounding portal vein embolization (PVE) regarding the short-term safety of PVE and long-term oncological benefit. This study aims to compare survival outcomes of patients subjected to major liver resection for colorectal liver metastases (CRLM) with or without PVE.

METHODS

All consecutive patients who underwent major liver resection for CRLM in four high volume liver centres between January 2000 and December 2015 were included. Major liver resection was defined as resection of at least three Couinaud liver segments. To reduce selection bias, propensity score matching was performed for PVE and non-PVE patients with overall and disease-free survival as primary endpoints. For matching, all patients who underwent PVE followed by a major liver resection were selected. Patients were matched to patients who had undergone major liver resection without PVE.

RESULTS

Of 745 patients undergoing major liver resection for CRLM, 53 patients (7%) underwent PVE before liver resection. In the overall cohorts, PVE patients had inferior DFS and a trend towards inferior OS. A total of 46 PVE patients were matched to 46 non-PVE patients to create comparable cohorts and between these two matched cohorts no differences in DFS (3-year DFS 16% vs 9%, p = 0.776) or OS (5-year OS 14% vs 14%, p = 0.866) were found.

CONCLUSIONS

This retrospective, matched analysis does not suggest a negative impact of PVE on long-term outcomes after liver resection in patients with CRLM.

Systematic review of perioperative and survival outcomes of liver resections with and without preoperative portal vein embolization for colorectal metastases

BACKGROUND

The aim of this systematic review was to evaluate perioperative and long term outcomes in patients who underwent PVE prior to liver resection for colorectal liver metastases.

METHODS

A systematic search of PubMed, MEDLINE, Embase and the Cochrane library was performed in accordance with PRISMA guidelines. Studies including patients who underwent liver resection with and without PVE (N-PVE) were included.

RESULTS

Thirteen studies including 1345 were included of which 539 patients had PVE and 806 had N-PVE. Eight studies reported that from a total of 450 patients who underwent PVE, 136 (30%) did not proceed to liver resection. In 114 (84%) patients this was due to disease progression. The postoperative morbidity was 42% (n = 151) after PVE and 10% (n = 35) developed postoperative liver failure after liver resection. Median overall survival, reported in all studies, was 38.9 months and 45.6 months respectively, following resection with PVE and N-PVE. The median disease free survival, reported in eight studies, was 15.7 (PVE) and 21.4 (N-PVE) months respectively.

CONCLUSION

Following PVE 70% of patients proceed to liver resection, with a 10% risk of postoperative liver failure. Tumour progression after PVE was the predominant reason for not proceeding to liver resection.

Liver surgery for metastatic colorectal cancer: the surgical oncologist perspective

Neoadjuvant/conversion chemotherapy has emerged as an indispensable tool to achieve resectability of initially unresectable metastatic colorectal cancer and improves oncological outcomes. In parallel, surgical strategy has adopted a more aggressive treatment approach to achieve complete tumor clearance. However, chemotherapy affects liver function and combined with extensive liver resection, morbidity has increased, thereby compromising oncological outcome. There is an imperative need for careful patient selection to optimize patient management. In this review, we discuss available evidence and indications for neoadjuvant treatment in the management of colorectal cancer liver metastases, on preoperative patient selection and identification of high-risk patients, potential treatment strategies to promote postoperative liver regeneration to avoid postoperative morbidity and potentially deleterious side effects of these therapies on tumor growth.

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.

Percutaneous transhepatic portal embolization using foam ethanolamine oleate and carbon dioxide (CO₂): a pilot study

BACKGROUND

Percutaneous transhepatic portal embolization (PTPE) can induce atrophy of the embolized- and hypertrophy of the residual area. These effects are advantageous in patients scheduled for extended hepatectomy.

PURPOSE

To evaluate the clinical safety and effectiveness of foam sclerotherapy with foam ethanolamine oleate (EO) and carbon dioxide (CO2) for PTPE before hepatectomy.

MATERIAL AND METHODS

We performed sclerotherapy for PTPE in 15 patients with: hepatocellular carcinoma (HHC; n = 9), bile duct carcinoma (n = 5), or metastatic liver tumor from colon cancer (n = 1). The foam contained 5% EO iopamidol (EOI) and CO2 at a 1:2 ratio. We compared the percentage of the pre- and post-PTPE future liver remnant (FLR) volumes and calculated the percent FLR volume (%FLR) increase after PTPE.

RESULTS

The amount of EOI used (range, 14-20 mL; median, 16.8 mL) was based on the volume of the target portal vein. Technical success was achieved in 14 of 15 patients (93%); the other patient presented with computed tomography evidence of recanalization 1 week after PTPE. The FLR volume before and after portal vein embolization was 599 ± 342 and 691 ± 318 cm(3), respectively (P < 0.01); the mean %FLR volume increase was 29.5%. There was no significant difference in the mean platelet count, total bilirubin, total aspartate aminotransferase, and total creatinine before and after PTPE. One patient suffered intra-abdominal bleeding that required transcatheter arterial embolization. No other patients developed major complications higher than grade 3.

CONCLUSION

Sclerotherapy using foam EOI and CO2 is clinically safe and effective for PTPE before hepatectomy.

Portal vein embolization effect on colorectal cancer liver metastasis progression: Lessons learned

Colorectal liver metastasis (CRLM) is the major cause of death in patients diagnosed with colorectal cancer. The gold standard treatment of CRLM is surgical resection. Yet, in the past, more than half of these patients were deemed unresectable due to the inadequate future liver remnant (FLR). The introduction of efficient portal vein embolization (PVE) preoperatively allowed more resections of metastasis in CRLM patients by stimulating adequate liver hypertrophy. However, several experimental and clinical studies reported tumor progression after PVE which critically influences the subsequent management of these patients. The underlying pathophysiological mechanism of tumor progression post-PVE is still not fully understood. In spite of the adverse effects of PVE, it remains a potentially curative procedure in patients who would remain otherwise unresectable because of the insufficient FLR. Currently, the challenge is to halt tumor proliferation following PVE in patients who require this technique. This could potentially be achieved by either attempting to suppress the underlying oncologic stimulus or by inhibiting tumor growth once observed after PVE, without jeopardizing liver regeneration. More research is still required to better identify patients at risk of experiencing tumor growth post-PVE.

DDX6 and its orthologs as modulators of cellular and viral RNA expression

DDX6 (Rck/p54), a member of the DEAD-box family of helicases, is highly conserved from unicellular eukaryotes to vertebrates. Functions of DDX6 and its orthologs in dynamic ribonucleoproteins contribute to global and transcript-specific messenger RNA (mRNA) storage, translational repression, and decay during development and differentiation in the germline and somatic cells. Its role in pathways that promote mRNA-specific alternative translation initiation has been shown to be linked to cellular homeostasis, deregulated tissue development, and the control of gene expression in RNA viruses. Recently, DDX6 was found to participate in mRNA regulation mediated by miRNA-mediated silencing. DDX6 and its orthologs have versatile functions in mRNA metabolism, which characterize them as important post-transcriptional regulators of gene expression.

Portal vein embolization improves rate of resection of extensive colorectal liver metastases without worsening survival

BACKGROUND

Most patients requiring an extended right hepatectomy (ERH) have an inadequate standardized future liver remnant (sFLR) and need preoperative portal vein embolization (PVE). However, the clinical and oncological impact of PVE in such patients remains unclear.

METHODS

All consecutive patients presenting at the M. D. Anderson Cancer Center with colorectal liver metastases (CLM) requiring ERH at presentation from 1995 to 2012 were studied. Surgical and oncological outcomes were compared between patients with adequate and inadequate sFLRs at presentation.

RESULTS

Of the 265 patients requiring ERH, 126 (47·5 per cent) had an adequate sFLR at presentation, of whom 123 underwent a curative resection. Of the 139 patients (52·5 per cent) who had an inadequate sFLR and underwent PVE, 87 (62·6 per cent) had a curative resection. Thus, the curative resection rate was increased from 46·4 per cent (123 of 265) at baseline to 79·2 per cent (210 of 265) following PVE. Among patients who underwent ERH, major complication and 90-day mortality rates were similar in the no-PVE and PVE groups (22·0 and 4·1 per cent versus 31 and 7 per cent respectively); overall and disease-free survival rates were also similar in these two groups. Of patients with an inadequate sFLR at presentation, those who underwent ERH had a significantly better median overall survival (50·2 months) than patients who had non-curative surgery (21·3 months) or did not undergo surgery (24·7 months) (P = 0·002).

CONCLUSION

PVE enabled curative resection in two-thirds of patients with CLM who had an inadequate sFLR and were unable to tolerate ERH at presentation. Patients who underwent curative resection after PVE had overall and disease-free survival rates equivalent to those of patients who did not need PVE.

Tumour progression and liver regeneration--insights from animal models

Surgery remains the only curative treatment for colorectal liver metastases. For patients with multiple bilobar spread, extended hepatectomy might be required to achieve complete margin-free resection. In such cases, portal vein occlusion has been developed to induce preoperative hypertrophy of the future remnant liver and increase the resectability rate. Evidence now suggests that liver regeneration after hepatectomy and portal vein occlusion has a protumorigenic role, either through an upregulation of growth factors and cytokines or by haemodynamic changes in the blood supply to the liver. Experimental studies have reported a stimulatory effect of liver regeneration on the tumoral volume of liver metastases and on the metastatic potential of cells engrafted in the liver; this effect seems to depend on the timing of hepatectomy and portal vein occlusion. However, the variability of animal tumour models that are used for research in experimental colorectal liver metastases might account for some of the inconsistent and conflicting results. This Review presents clinical and experimental data pertaining to whether liver regeneration causes proliferation of tumour cells. We also analyse the different animal models of colorectal liver metastases in use and discuss current controversies in the field.

Right and extended-right hepatectomies for unilobar colorectal metastases: impact of portal vein embolization on long-term outcome and liver recurrence

BACKGROUND

Portal vein embolization (PVE) is an effective procedure to increase the future remnant liver (FRL) before major hepatectomy. A controversial issue is that PVE may stimulate tumor growth and can be associated with poor prognosis after liver resection for colorectal liver metastases (CRLM). The aim of this study was to evaluate the impact of PVE on long-term survival following major hepatectomy for CRLM.

METHODS

Between 1998 and 2010, 100 right and extended-right hepatectomies for unilobar, right-sided CRLM were performed. Of the group, 20 patients underwent preoperative PVE (group A). The control patients (group B; 20 patients) were selected by matching with the group A patients.

RESULTS

It was found that 25 patients (25/40; 62.5%) had developed tumor recurrence. The rate of global recurrence was not significantly different in groups A and B (65% vs 60%, respectively; P = .744). The specific overall intrahepatic recurrence rate was 42.5% (17 of 40 patients) and was not significantly different in groups A and B (45% vs 40%, respectively; P = .749). The 5-year overall and disease-free survival rates were similar in groups A and B (42.9% and 33.6% vs 42.1% and 27.7%, respectively). The 5-year specific liver-disease-free survival was 45.3% in group A and 53.5% in group B (P = .572). On multivariate analysis of all 100 hepatectomies, R1 resection (P = .013) was found to be the only independent predictor of liver-disease-free survival.

CONCLUSION

This study showed that PVE did not affect overall survival and specific liver-disease-free survival in patients undergoing right or right-extended hepatectomy for unilobar, right-sided CRLM.

Portal vein embolization before liver resection: a systematic review

Purpose

This is a review of literature on the indications, technique, and outcome of portal vein embolization (PVE).

Methods

A systematic literature search on outcome of PVE from 1990 to 2011 was performed in Medline, Cochrane, and Embase databases.

Results

Forty-four articles were selected, including 1,791 patients with a mean age of 61 ± 4.1 years. Overall technical success rate was 99.3 %. The mean hypertrophy rate of the FRL after PVE was 37.9 ± 0.1 %. In 70 patients (3.9 %), surgery was not performed because of failure of PVE (clinical success rate 96.1 %). In 51 patients (2.8 %), the hypertrophy response was insufficient to perform liver resection. In the other 17 cases, 12 did not technically succeed (0.7 %) and 7 caused a complication leading to unresectability (0.4 %). In 6.1 %, resection was cancelled because of local tumor progression after PVE. Major complications were seen in 2.5 %, and the mortality rate was 0.1 %. A head-to-head comparison shows a negative effect of liver cirrhosis on hypertrophy response. The use of n-butyl cyanoacrylate seems to have a greater effect on hypertrophy, but the difference with other embolization materials did not reach statistical significance. No difference in regeneration is seen in patients with cholestasis or chemotherapy.

Conclusions

Preoperative PVE has a high technical and clinical success rate. Liver cirrhosis has a negative effect on regeneration, but cholestasis and chemotherapy do not seem to have an influence on the hypertrophy response. The use of n-butyl cyanoacrylate may result in a greater hypertrophy response compared with other embolization materials used.

Function and volume recovery after partial hepatectomy: influence of preoperative liver function, residual liver volume, and obesity

BACKGROUND

The regenerative capacity of the liver is an essential pre-condition for the successful application of partial hepatectomy. However, the actual kinetics of functional recovery remains unspecified and no adequate tool for its clinical monitoring has yet been available.

METHODS

Eighty-five patients receiving major hepatectomy were investigated from the preoperative evaluation until 12 weeks after surgery. Liver function was determined by the LiMAx test for the enzymatic capacity of cytochrome P450 1A2. Liver volume was determined by volumetric analysis of repeated computer tomography scans. Functional and volume recovery were compared during follow-up.

RESULTS

Major hepatectomy decreased liver function capacity to 35.7 ± 13.8% of preoperative function. It was shown that functional recovery already reaches 77.2 ± 33.5% of preoperative values within 10 days. The actual kinetics were dependent from the type and extent of hepatectomy. Complete functional restoration was achieved within 12 weeks, while liver volume still remained at 73.2 ± 14.8% of preoperative. A constant but interindividually variable correlation between function and volume was observed at all points in time.

CONCLUSION

Partial hepatectomy leads to fast and complete functional recovery, while volume recovery is delayed and remains often incomplete. The functional recovery is mainly influenced by the preoperative liver function, the residual liver volume, and by obesity.

Portal vein occlusion before major hepatectomy in patients with colorectal liver metastases: rationale, indications, technical aspects, complications and outcome

Surgery is the only curative treatment for colorectal liver metastases (CRLM), but resection should be total with tumor-free margins and the remaining parenchyma, functionally evaluated. The rationale behind portal vein embolization (PVE) to reduce the risk of these hepatic resections is threefold: (i) surgery for CRLM has become more and more aggressive, and hepatocellular insufficiency represents the leading cause of mortality after major hepatectomy for hepatic metastasis (HM), (ii) underlying hepatic disease occurs more frequently than previously thought in these patients having undergone neoadjuvant chemotherapy, and can alter hepatic function and/or hinder postoperative regeneration, and (iii) the operative risk is increased if major hepatectomy is associated with resection of the primary tumor. The goal of this update is to review the reasons behind and the indications for PVE, to analyze the literature pertaining to whether PVE should be routine or selective, and to tackle certain technical aspects, all within the framework of the treatment of CRLM.

Impact of portal vein embolization on long-term survival of patients with primarily unresectable colorectal liver metastases

BACKGROUND

: Portal vein embolization (PVE) increases the resectability of initially unresectable colorectal liver metastases (CLM). This study evaluated long-term survival in patients with CLM who underwent hepatectomy following PVE.

METHODS

: In a retrospective analysis patients treated by PVE before major hepatectomy were compared with those who did not have PVE, and with those who had PVE without resection.

RESULTS

: Of 364 patients who underwent hepatectomy, 67 had PVE beforehand and 297 did not. Those who had PVE more often had more than three liver metastases (68 versus 40.9 per cent; P < 0.001) that were more frequently bilobar (78 versus 55.2 per cent; P < 0.001), and a higher proportion underwent extended hepatectomy (63 versus 18.1 per cent; P < 0.001). Postoperative morbidity rates were 55 and 41.1 per cent respectively (P = 0.035), and overall 3-year survival rates were 44 and 61.0 per cent (P = 0.001). Thirty-two other patients who were treated by PVE but did not undergo resection all died within 3 years.

CONCLUSION

: PVE increased the resectability rate of initially unresectable CLM. Among patients who had PVE, long-term survival was better in those who had resection than in those who did not. PVE is of importance in the multimodal treatment of advanced CLM.

Systematic review of tumour number and outcome after radical treatment of colorectal liver metastases

Background

Resection of colorectal liver metastases (CLMs) is potentially curative but the effect of tumour number on prognosis is uncertain. This study compared the prognosis after resection and/or ablation of between one and three, or four or more CLMs.

Methods

A systematic literature review from January 2000 to June 2008 was performed. Study selection and data extraction were standardized, and analysis included assessment of methodological quality, heterogeneity and bias. Main outcomes were 3- and 5-year survival. A meta-analysis comparing radical treatment in the two groups was performed using the hazard ratio for overall survival.

Results

Of 1307 studies screened, 46 (9934 patients) were included in the analysis. Methodological quality was variable, and there was significant heterogeneity and reporting bias. The overall 5-year survival rate after radical treatment ranged from 7 to 58 per cent. Pooled hazard ratio for overall survival was 1·67 (95 per cent confidence interval 1·43 to 1·95; P &lt; 0·001). Median reported 5-year survival for patients with four or more CLMs was 17·1 per cent.

Conclusion

Radical treatment of more than three CLMs results in poorer overall survival. Nevertheless, 5-year survival is achievable and the number of lesions should not, of itself, be used to exclude patients from surgery.

Long-term survival and disease recurrence following portal vein embolisation prior to major hepatectomy for colorectal metastases

BACKGROUND

Portal vein embolisation (PVE) can be used to increase the remnant liver parenchyma volume before major hepatectomy but may stimulate tumour growth. The pattern of disease recurrence and long-term survival has not been adequately addressed.

METHODS

Over a period of 7 years 36 patients underwent preoperative PVE before resection of four or more liver segments for colorectal cancer (CRC) liver metastases. PVE was performed when the future liver remnant (FLR) assessed by magnetic resonance imaging (MRI) scan volumetry was less than 30%. Disease-free and overall survival was compared with a control group (65 patients) undergoing extended right/right hepatectomy for CRC metastases without PVE during the same time period.

RESULTS

PVE was successful in all patients. PVE increased the median FLR volume by 37% [295 ml (22%) to 404 ml (32%), p < 0.0001]. 61% of patients undergoing PVE proceeded to liver resection (n = 22). Twelve patients (33%) developed disease progression following PVE. The 5-year survival after liver resection with PVE was 25%, compared with 50% without PVE. The 5-year disease-free survival was 30% post PVE and 50% without PVE.

CONCLUSION

We conclude that PVE significantly increases the future liver remnant. Only two-thirds of patients proceed to resection because of disease progression. Long-term survival is less than in patients who do not require PVE. The effect of PVE on tumour growth requires investigation.

Major hepatectomy for colorectal metastases: is preoperative portal occlusion an oncological risk factor?

BACKGROUND

This study investigates oncological risks and benefits of portal occlusion (PO) in major resection for colorectal liver metastases (CLM).

METHODS

Between 1995 and 2004, 107 patients were scheduled for major hepatectomy for CLM. Of these, 53 patients were selected for PO due to insufficient future liver remnant (FLR), and 54 patients had straightforward hepatectomy. Associations of clinicopathologic factors with resectability, and outcome after PO were analyzed.

RESULTS

21 of 53 patients (39.6%) after PO were unresectable. These patients had a significant smaller volume of the FLR than the 32 resected patients after PO (P = .029). In total, 17 patients (80.9%) did not undergo resection due to cancer progression. Among these, 11 patients (52.4%) exhibited either a progression of known metastases located in the occluded lobes, or new metastases in the nonoccluded portion of the liver. In another 4 individuals (19%), the decision against resection resulted from insufficient hypertrophy of the FLR. Following major hepatectomy, the 5-year survival was 43.66%. Although there was a significantly higher rate of extended hepatectomies versus formal hepatectomies (P < .001), more bilobar distributed metastases versus unilobar manifestations (P = .015), and a smaller resection margin (P = .01) in patients who had PO, no adverse effect on mortality, morbidity, recurrence and survival was observed.

CONCLUSION

Unresectability after PO is a major problem that warrants multidisciplinary improvements, and randomization to resection with or without PO remains ethically problematic. However, following adequate patient selection, PO may provide a significant survival benefit for patients with prior unresectable CLM.

Trans-ileocecal portal vein embolization as a preoperative treatment for right trisegmentectomy with caudate lobectomy

BACKGROUND AND OBJECTIVES

The indication of preoperative portal vein embolization (PVE) has been expanded to hepatocellular carcinoma, cholangiocellular carcinoma (CCC), hepatic metastasis, and gallbladder (GB) cancer as well as hilar cholangiocarcinoma (hCC). However, biliary cancers sometimes cause peritoneal dissemination.

PATIENTS AND METHODS

We performed our preoperative trans-ileocecal-vein PVE (TIPE) method on 14 (3 GB cancer, 1 CCC, and 10 hCC), whose estimated residual liver volume was <30%.

RESULTS

Out of 14 patients, peritoneal dissemination was encountered in two patients with GB cancer and one with hCC (21.4%) during our procedure. The estimated residual liver volume was 37.4 +/- 2.7% at 14 days after PVE in patients without predisposing cholangitis, while those in patients with cholangitis was 29.3 +/- 1.3% (P = 0.0002). No major complication due to the procedure was encountered in this series.

CONCLUSIONS

PTPE could be the first choice for patients with hCC, hepatocellular carcinoma, and hepatic metastases. Although the TIPE proposed here has some potential disadvantages, we would recommend it especially for patients with GB cancer because of its high potential to cause cancerous peritonitis. When a patient had predisposing cholangitis, radical operation should be scheduled on >21 days after PVE rather than on 14 days.