Right portal vein embolization before right hepatectomy for unilobar colorectal liver metastases reduces the intrahepatic recurrence rate

Portal Vein Embolization: Rationale, Techniques, and Outcomes to Maximize Remnant Liver Hypertrophy with a Focus on Contemporary Strategies

Hepatectomy remains the gold standard for curative therapy for patients with limited primary or metastatic hepatic tumors as it offers the best survival rates. In recent years, the indication for partial hepatectomy has evolved away from what will be removed from the patient to the volume and function of the future liver remnant (FLR), i.e., what will remain. With this regard, liver regeneration strategies have become paramount in transforming patients who previously had poor prognoses into ones who, after major hepatic resection with negative margins, have had their risk of post-hepatectomy liver failure minimized. Preoperative portal vein embolization (PVE) via the purposeful occlusion of select portal vein branches to promote contralateral hepatic lobar hypertrophy has become the accepted standard for liver regeneration. Advances in embolic materials, selection of treatment approaches, and PVE with hepatic venous deprivation or concurrent transcatheter arterial embolization/radioembolization are all active areas of research. To date, the optimal combination of embolic material to maximize FLR growth is not yet known. Knowledge of hepatic segmentation and portal venous anatomy is essential before performing PVE. In addition, the indications for PVE, the methods for assessing hepatic lobar hypertrophy, and the possible complications of PVE need to be fully understood before undertaking the procedure. The goal of this article is to discuss the rationale, indications, techniques, and outcomes of PVE before major hepatectomy.

Cryotherapy for liver metastases

BACKGROUND

The liver is affected by two of the most common groups of malignant tumours: primary liver tumours and liver metastases from colorectal carcinoma. Liver metastases are significantly more common than primary liver cancer and long-term survival rates reported for patients after radical surgical treatment is approximately 50%. However, R0 resection (resection for cure) is not feasible in the majority of patients. Cryotherapy is performed with the use of an image-guided cryoprobe which delivers liquid nitrogen or argon gas to the tumour tissue. The subsequent process of freezing is associated with formation of ice crystals, which directly damage exposed tissue, including cancer cells.

OBJECTIVES

To assess the beneficial and harmful effects of cryotherapy compared with no intervention, other ablation methods, or systemic treatments in people with liver metastases.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE Ovid, Embase Ovid, and six other databases up to June 2018.

SELECTION CRITERIA

Randomised clinical trials assessing beneficial and harmful effects of cryotherapy and its comparators for liver metastases, irrespective of the location of the primary tumour.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We extracted information on participant characteristics, interventions, study outcomes, and data on the outcomes important for our review, as well as information on the design and methodology of the trials. Two review authors independently assessed risk of bias in each study. One review author performed data extraction and a second review author checked entries.

MAIN RESULTS

We found no randomised clinical trials comparing cryotherapy versus no intervention or versus systemic treatments; however, we identified one randomised clinical trial comparing cryotherapy with conventional surgery. The trial was conducted in Ukraine. The trial included 123 participants with solitary, or multiple unilobar or bilobar liver metastases; 63 participants received cryotherapy and 60 received conventional surgery. There were 36 women and 87 men. The primary sites for the metastases were colon and rectum (66.6%), stomach (7.3%), breast (6.5%), skin (4.9%), ovaries (4.1%), uterus (3.3%), kidney (3.3%), intestines (1.6%), pancreas (1.6%), and unknown (0.8%). The trial was not reported sufficiently enough to assess the risk of bias of the randomisation process, allocation concealment, or presence of blinding. It was also not possible to assess incomplete outcome data and selective outcome reporting bias. The certainty of evidence was low because of risk of bias and imprecision.The participants were followed for up to 10 years (minimum five months). The trial reported that the mortality at 10 years was 81% (51/63) in the cryotherapy group and 92% (55/60) in the conventional surgery group. The calculated by us relative risk (RR) with 95% Confidence Interval (CI) was: RR 0.88, 95% CI 0.77 to 1.02. We judged the evidence as low-certainty evidence. Regarding adverse events and complications, separately and in total, our calculation showed no evidence of a difference in recurrence of the malignancy in the liver: 86% (54/63) of the participants in the cryotherapy group and 95% (57/60) of the participants in the conventional surgery group developed a new malignancy (RR 0.90, 95% CI 0.80 to 1.01; low-certainty evidence). The frequency of reported complications was similar between the cryotherapy group and the conventional surgery group, except for postoperative pain. Both insignificant and pronounced pain were reported to be more common in the cryotherapy group while intense pain was reported to be more common in the conventional surgery group. However, the authors did not report whether there was any evidence of a difference. There were no intervention-related mortality or bile leakages.We identified no evidence for health-related quality of life, cancer mortality, or time to progression of liver metastases. The study reported tumour response in terms of the carcinoembryonic antigen level in 69% of participants, and reported results in the form of a graph for 30% of participants. The carcinoembryonic antigen level was lower in the cryotherapy group, and decreased to normal values faster in comparison with the control group (P < 0.05).

FUNDING

the trial did not provide information on funding.

AUTHORS' CONCLUSIONS

The evidence for the effectiveness of cryotherapy versus conventional surgery in people with liver metastases is of low certainty. We are uncertain about our estimate and cannot determine whether cryotherapy compared with conventional surgery is beneficial or harmful. We found no evidence for the benefits or harms of cryotherapy compared with no intervention, or versus systemic treatments.

Beyond the Knife: The Evolving Nonsurgical Management of Oligometastatic Colorectal Cancer

In patients with liver-limited oligometastatic disease, the goal of treatment can be curative intent. Historically, this was accomplished in patients presenting with upfront resectable disease. The availability of increasingly efficacious chemotherapy and biologic combinations with encouraging response rates led to the potential to convert unresectable disease to resectability. Beyond the backbone of surgery, we now have a portfolio of locoregional strategies to consider.From an interventional radiology perspective, the use of portal vein embolization can facilitate hypertrophy of the liver in anticipation of resection, thus converting unresectable disease to one amenable to a surgical approach with curative intent. Technological advances in liver-directed ablative therapies have afforded the possibility of eliminate radiographically evident disease with the hope for long-term disease control. Advanced radiotherapy techniques are further increasing the therapeutic options for patients with metastatic colorectal cancer. Improvements in external-beam radiotherapy over the past 2 decades include image-guided radiotherapy, intensity-modulated radiotherapy, stereotactic body radiotherapy, and proton-beam therapy. Finally, selective internal radiation therapy (SIRT) with microspheres labeled with the β-emitter ⁹⁰Y enable targeted delivery of radiation to hepatic tumors. A coordinated multidisciplinary approach is required to integrate these nonsurgical adjuncts in an evidence-based manner to optimize outcomes for patients with potentially resectable metastatic disease. In this article, we summarize recent developments in systemic therapy, radiotherapy, and interventional liver-directed therapies that have changed the treatment landscape for patients with oligometastatic colorectal cancer.

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.

Oncological Outcomes of Major Liver Resection Following Portal Vein Embolization: A Systematic Review and Meta-analysis

BACKGROUND

Preoperative portal vein occlusion with either percutaneous portal vein embolization (PVE) or portal vein ligation is routinely used to induce liver hypertrophy prior to major liver resection in patients with hepatic malignancy. While this increases the future liver remnant, and hence the number of patients suitable for resection, recent evidence suggests that induction of liver hypertrophy preoperatively may promote tumor growth and increase recurrence rates. The aims of this current study were to evaluate the impact of PVE on hepatic recurrence rate and survival in patients with colorectal liver metastases (CRLM).

METHODS

The MEDLINE, EMBASE and Web of Science databases were searched to identify studies assessing the oncological outcomes of patients undergoing major liver resection for CRLM following PVE. Studies comparing patients undergoing one-stage liver resection with or without preoperative PVE were included. The primary outcome was postoperative hepatic recurrence (PHR), while secondary outcomes were 3- and 5-year overall survival (OS).

RESULTS

Of the 2131 studies identified, six non-randomized studies (n = 668) met the eligibility criteria, comparing outcomes of patients undergoing major liver resection with or without PVE (n = 182 and n = 486, respectively). No significant difference was observed in PHR (odds ratio [OR] 0.78; 95 % confidence interval [CI] 0.42-1.44), 3-year OS (OR 0.80; 95 % CI 0.56-1.14) or 5-year OS (OR 1.12; 95 % CI 0.40-3.11).

CONCLUSIONS

PVE does not have any adverse effect on PHR or OS in patients undergoing major liver resection for CRLM. Further studies based on individual patient data are needed to provide definitive answers.

Improved liver function after portal vein embolization and an elective right hepatectomy

BACKGROUND

Portal vein embolization (PVE) is used before extensive hepatic resections to increase the volume of the future remnant liver within acceptable safety margins (conventionally >0.6% of the patient's weight). The objective was to determine whether pre-operative PVE impacts on post-operative liver function independently from the increase in liver volume.

METHODS

The post-operative liver function of patients who underwent an anatomical right liver resection with (n = 28) and without (n = 53) PVE were retrospectively analysed. Donors of the right liver were also analysed (LD) (n = 17).

RESULTS

Patient characteristics were similar, except for age, weight and American Society of Anesthesiologists (ASA) score that were lower in LD. Post-operative factor V and bilirubin levels were, respectively, higher and lower in patients with PVE compared with patients without PVE or LD (P < 0.05). Patients with PVE had an increased blood loss, blood transfusions and sinusoidal obstruction syndrome. The day-3 bilirubin level was 40% lower in the PVE group compared with the no-PVE group after adjustment for body weight, chemotherapy, operating time, Pringle time, blood transfusions, remnant liver volume, pre-operative bilirubin level and pre-operative prothrombin ratio (P = 0.001).

CONCLUSIONS

For equivalent volumes, the immediate post-operative hepatic function appears to be better in livers prepared with PVE than in unprepared livers. Future studies should analyse whether the conventional inferior volume limit that allows a safe liver resection may be lowered when a PVE is performed.

Predicting early intrahepatic recurrence after curative resection of colorectal liver metastases with molecular markers

BACKGROUND

The aim of this case-control study was to identify clinicopathological factors and test three relevant biomarkers for their ability to predict early intrahepatic recurrence after curative liver resection for colorectal liver metastases (CLM).

METHODS

Of the 184 patients with CLM undergoing hepatectomy between January 2007 and December 2009, thirty patients had intrahepatic disease recurrence within 6 months. The control group was randomly selected from a cohort of patients between April 1997 and December 2005 who have survived without disease recurrence after CLM resection for over 5 years. Both groups were matched for size of metastasis greater than 5.0 cm, the presence of multiple metastases, and synchronous versus metachronous CLM. The final study population consisted of 60 patients with CLM undergoing R0 hepatectomy, 30 of whom had early intrahepatic-only recurrences (study group) and 30 patients without recurrence for more than 5 years (control group). Both groups were analyzed and compared for the presence of clinical factors and expression levels of CD133, survivin, and Bcl-2 within tumor tissue.

RESULTS

Characteristics of patients were similar between the two groups except primary tumor location and administration of postoperative chemotherapy. Expression level of CD133 and survivin were significantly increased in tumors of patients with recurrence compared to patients without recurrence. On multivariate analysis high tumor expression levels of CD133 (odds ratio [OR] 14.7, confidence interval [CI] 1.8-121.3, p = 0.012) and survivin (OR 9.5, CI 2.1-44.3, p = 0.004) and postoperative chemotherapy (OR 4.8, CI 1.01-22.9, p = 0.049) were independent factors associated with early intrahepatic recurrence.

CONCLUSIONS

Tumor expression levels of CD133 and survivin may be a useful predictor of early intrahepatic recurrence after hepatectomy for CLM. Administration of postoperative chemotherapy may prevent early intrahepatic recurrence.

Portal vein embolization and its effect on tumour progression for colorectal cancer liver metastases

BACKGROUND

The aim of this study was to evaluate the long-term outcomes of patients with colorectal cancer liver metastasis (CRCLM) exhibiting disease progression after portal vein embolization (PVE).

METHODS

Patients with CRCLM requiring PVE before hepatectomy between 2003 and 2014 were included. Clinical variables, and liver and tumour volumes determined by three-dimensional CT volumetry were assessed before and after PVE. Overall and disease-free survival data were obtained. Univariable and multivariable logistic regression analyses were performed to identify predictors of tumour progression after PVE.

RESULTS

Of 141 patients who underwent PVE, 93 (66.0 per cent) had tumour progression and 17 (12.1 per cent) developed new contralateral lesions. Significantly fewer patients had resectable disease in the group with disease progression than among those with stable disease: 43 (46 per cent) of 93 versus 36 (75 per cent) of 48 respectively (P = 0.001). Median survival was similar in patients with and without tumour growth after PVE: 22.5 versus 26.0 months for patients with unresectable tumours (P = 0.706) and 46.2 versus 52.2 months for those with resectable disease (P = 0.953). However, disease-free survival for patients with tumour progression after PVE was shorter than that for patients with stable disease (6.0 versus 20.2 months; P = 0.045). Response to neoadjuvant chemotherapy was the only significant factor associated with tumour progression in multivariable analysis.

CONCLUSION

Tumour progression after PVE did not affect overall survival, but patients with resected tumours who had tumour growth after embolization experienced earlier recurrence. A borderline response to neoadjuvant chemotherapy seemed to be associated with tumour progression after PVE.

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.

Portal vein embolization and ligation for extended hepatectomy

Portal vein occlusion through embolization or ligation (PVE, PVL) offers the possibility of increasing the future liver remnant (FLR) and thus reducing the risk of hepatic failure after extended hepatectomy We reviewed the indications, scope and applicability of PVE/PVL in treatment of primary and secondary liver tumours. A thorough PubMED, Embase, Ovid and Cochrane database search was carried out for all original articles with 30 patients or more undergoing either PVE and any patient series with PVL, irrespective of number with outcome measure in at least one of the following parameters: FLR volume change, complications, length of stay, time to surgery, proportion resectable and survival data. PVE can be performed with a technical success in 98.9 % (95 % confidence interval 97-100) patients, with a mean morbidity of 3.13 % (95 % CI 1.21-5.04) and a median in-hospital stay of 2.1 (range 1-4) days (very few papers had data on length of stay following PVE). The mean increase in volume of the FLR following PVE was 39.75 % (95 % CI 30.8-48.6) facilitating extended liver resection after a mean of 37.13 days (95 % CI 28.51-45.74) with a resectability rate of 76.88 % (95 % CI 70.91-82.84). Morbidity and mortality following such extended liver resections after PVE is 26.58 % (95 % CI 19.20-33.95) and 2.59 % (95 % CI 1.34-3.83) respectively with an in-patient stay of 13.57 days (95 % CI 9.8-17.37). However following post-PVE liver hypertrophy 6.29 % (95 % CI 2.24-10.34) patients still have post-resection liver failure and up to 14.2 % (95 % CI -8.7 to 37) may have positive resection margins. Up to 4.80 % (95 % CI 2.07-7.52) have failure of hypertrophy after PVE and 17.46 % (95 % CI 11.89-23.02) may have disease progression during the interim awaiting hypertrophy and subsequent resection. PVL has a greater morbidity and duration of stay of 5.72 % (95 % CI 0-15.28) and 10.16 days (95 % CI 6.63-13.69) respectively; as compared to PVE. Duration to surgery following PVL was greater at 53.6 days (95 % CI 32.14-75.05). PVL induced FLR hypertrophy by a mean of 64.65 % (95 % CI 0-136.12) giving a resectability rate of 63.68 % (95 % CI 56.82-70.54). PVL failed to produce enough liver hypertrophy in 7.4 % of patients (95 % CI 0-16.12). Progression of disease following PVL was 29.29 (95%CI 15.69-42.88). PVE facilitates an extended hepatectomy in patients with limited or inadequate FLR, with good short and long-term outcomes. Patients need to be adequately counselled and consented for PVE and EH in light of these data. PVL would promote hypertrophy as well, but clearly PVE has advantages as compared to PVL on account of its inherent "minimally invasive" nature, fewer complications, length of stay and its feasibility to have shorter times to surgery.

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.

Interventional oncologic approaches to liver metastases

Metastatic liver disease is the most common cause of death in cancer patients. Complete surgical resection is currently considered the only curative treatment, with only about 25% of patients being amenable to surgery. Therefore, a variety of interventional oncologic techniques have been developed for treating secondary liver malignancies. The aim of these therapies is either to allow patients with unresectable tumors to become surgical candidates, provide curative treatment options in nonsurgical candidates, or improve survival in a palliative or even curative approach. Among these interventional therapies are transcatheter therapies such as portal vein embolization, hepatic artery infusion chemotherapy, transarterial chemoembolization, and radioembolization, as well as interstitial techniques, particularly radiofrequency ablation as the most commonly applied technique. The rationale, application and clinical results of each of these techniques are reviewed on the basis of the current literature. Future prospects such as gene therapy and immunotherapy are introduced.

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 biomarkers expression before and after portal vein embolization on recurrence after two-stage hepatectomy for colorectal liver metastases

BACKGROUND

The adverse oncological effect of portal vein embolization (PVE) in patients with colorectal liver metastases (CLM) remains controversial. This study was designed to evaluate the effect of PVE on change of tumor characteristics using tumor specimens obtained from sequential hepatectomy before and after PVE.

METHODS

Between December 1996 and April 2009, among 55 patients who achieved two-stage hepatectomy (TSH) combined with PVE, 39 had available cancer tissue blocks from both the first- and second-stage hepatectomy and constituted the study population. The immunohistochemistry of Ki67 and Bcl-2 before and after PVE was performed. Biomarker expressions and clinicopathological variables were assessed and their impact on recurrence was analyzed.

RESULTS

Whereas tumor volume and carcinoembryonic serum level significantly increased after PVE, the expression of Ki67 and Bcl-2 remained similar before and after PVE. The Bcl-2 ratio (expressed as Bcl-2 after PVE over Bcl-2 before PVE) was an independent prognostic factor for recurrence-free survival (P=0.030). Patients with Bcl-2 ratio ≤ 1 had a significantly longer median recurrence-free survival compared with those with Bcl-2 ratio >1 receiving or not receiving adjuvant chemotherapy (24.8 months versus 8.9 or 5.8 months, respectively).

CONCLUSION

Bcl-2 ratio may predict early recurrence and identify patients who do not require postoperative chemotherapy in patients undergoing TSH with PVE for CLM.

Infusion of CD133+ bone marrow-derived stem cells after selective portal vein embolization enhances functional hepatic reserves after extended right hepatectomy: a retrospective single-center study

OBJECTIVE

This study was designed to evaluate the clinical outcome of patients undergoing portal vein embolization (PVE) and autologous CD133 bone marrow-derived stem cell (CD133+ BMSC) application before extended right hepatectomy.

BACKGROUND

We have previously shown that portal venous infusion of CD133+ BMSCs substantially increases hepatic proliferation, when compared with PVE alone.

METHODS

: Among 40 consecutive patients with a median follow-up of 28 months (7.4-57.2) scheduled for extended right hepatectomy, we compared a preconditioned group with PVE and CD133+ BMSC cotreatment (PVE+SC group, n = 11) and a group pretreated only with PVE (PVE group, n = 11). Functional and overall outcomes after extended right hepatectomy were evaluated. Patients without presurgical treatment served as controls (n = 18).

RESULTS

In preconditioned patients, mean hepatic growth of segments II/III 14 days after PVE in the PVE+SC group was significantly higher (138.66 mL ± 66.29) when compared with that of PVE group patients (62.95 mL ± 40.03; P = 0.004). There were no significant differences among all 3 groups regarding general and oncological characteristics and functional parameters on postoperative day (POD) 7. Lack of hepatic preconditioning, extrahepatic extension of resection, and postoperative complications were of negative prognostic value, using univariate analysis (P < 0.05). In multivariate analysis, freedom from postoperative major complications (P = 0.012), coagulation status on POD 7 (international normalized ratio < 1.4; P = 0.027), and presurgical expansion of the future liver remnant volume (P = 0.048) were positively associated with overall survival. Post hoc analysis revealed a better survival for the PVE+SC group (P = 0.028) compared with the PVE group (P = 0.094) and compared with controls.

CONCLUSION

Promising data from this survival analysis suggest that PVE, together with CD133+ BMSC pretreatment, could positively impact overall outcomes after extended right hepatectomy.

Two-stage hepatectomy for multiple bilobar colorectal liver metastases

BACKGROUND

As surgical resection of colorectal liver metastases (CLM) remains the only treatment for cure, efforts to extend the surgical indications to include patients with multiple bilobar CLM have been made. This study evaluated the long-term outcome, safety and efficacy of two-stage hepatectomy (TSH) for CLM in a large cohort of patients.

METHODS

Patients undergoing surgery between December 1996 and December 2009 were reviewed. The early postoperative and long-term outcomes as well as the patterns of failure to complete TSH and its clinical implications were analysed.

RESULTS

Eighty patients were scheduled to undergo TSH. Sixty-one patients had completion of TSH combined with (58 patients), or without (3) portal vein embolization/ligation (PVE/PVL). Five patients were excluded after first-stage hepatectomy and 14 after PVE/PVL. The 5-year overall survival rate and median survival in patients who completed TSH were 32 per cent and 39·6 months respectively, and corresponding recurrence-free values were 11 per cent and 9·4 months respectively. Six patients were alive beyond 5 years after TSH. Multivariable logistic regression analysis showed that failure to complete TSH was driven by two independent prognostic scenarios: three or more CLM in the future remnant liver (FRL) combined with age over 70 years predicted tumour progression after first-stage hepatectomy, and three or more CLM in the FRL combined with carcinomatosis at the time of first-stage hepatectomy predicted the development of additional FRL metastases after PVE/PVL.

CONCLUSION

A therapeutic strategy using TSH provided acceptable long-term survival with no postoperative mortality. Further efforts are needed to increase the number of patients who undergo TSH successfully.

Risk factors for liver failure and mortality after hepatectomy associated with portal vein resection

OBJECTIVE

To report the postoperative outcome of hepatectomy associated with portal vein resection (PVR) and to identify risk factors of clinical value for predicting postoperative liver failure and mortality.

SUMMARY BACKGROUND DATA

Resection of the portal vein during hepatectomy allows an increase in the number of patients who may benefit from a potentially curative operation that is, however, technically difficult and may increase postoperative morbidity and mortality. Few data are available about risk factors for liver failure and mortality after such extensive operations.

METHODS

Between July 1996 and July 2008, a total of 1348 patients were operated on for liver disease in our institution. Among them, 55 patients underwent liver resection associated with PVR. Medical records of these patients were prospectively collected and retrospectively analyzed.

RESULTS

Overall mortality for this selected group of patients was 7.2%. Irreversible liver failure was the main cause of death. Overall morbidity was 58.1%. A total of 94% of the patients (n = 52) underwent a major (≥ 3 segments) or an extended > 4 segments) right or left hepatectomy. Univariate analysis showed that male gender (P = 0.004), extended liver resection (P = 0.028), and, particularly, extended right hepatectomy (P = 0.015) were significantly associated with an increased risk of postoperative liver failure. Male gender was the single independent risk factor for liver failure. Moreover, the presence of liver steatosis (P = 0.014), an extended right hepatectomy procedure (P = 0.047), and postoperative liver failure (P = 0.046) were significantly associated with an increased rate of postoperative mortality.

CONCLUSION

The present study confirmed that major or extended hepatic resection with PVR can be performed with acceptable overall morbidity and mortality rates. Preoperative selection of the patients should take in consideration the gender and the extent of hepatic resection to avoid irreversible postoperative liver failure. Extended right hepatectomy with PVR should be carefully considered in patients with liver steatosis due to the high risk of postoperative mortality.

Portal vein embolization (prior to major hepatectomy) effects on regeneration, resectability, and outcome

Portal vein embolization (PVE) is used to increase the volume and function of the liver that will remain after extensive liver resection. Operative outcomes are improved in properly selected patients who undergo PVE and experience adequate future liver remnant (FLR) hypertrophy. Absolute volume and volume change of the FLR after PVE (interpreted in context of liver disease) predict adequate liver function postresection. Oncologic outcomes following resection in patients with appropriately applied PVE are excellent.

Sinusoidal obstruction syndrome compromises liver regeneration in patients undergoing two-stage hepatectomy with portal vein embolization

PURPOSE

Several factors have been reported to affect liver regeneration after portal vein embolization (PVE); however, the effect of sinusoidal obstruction syndrome (SOS) has not been evaluated. Therefore, we assessed the effect of SOS on liver regeneration after PVE in patients with multiple bilobar colorectal liver metastases scheduled to undergo two-stage hepatectomy (TSH) combined with PVE.

METHODS

The subjects of this study were 78 patients prospectively scheduled to undergo TSH between December 1996 and August 2009. Archived formalin-fixed, paraffin-embedded nontumoral tissue samples were collected from the 1st- and 2nd-stage hepatectomies in 42 and 45 patients, respectively, and SOS and steatohepatitis were diagnosed pathologically. We analyzed the clinicopathological variables affecting liver regeneration after PVE.

RESULTS

Sinusoidal obstruction syndrome was diagnosed in 11 (26.2%) and 20 patients (44.4%) at the time of the 1st- and 2nd-stage hepatectomy, respectively. Patients with SOS at the 1st-stage hepatectomy had a significantly lower hypertrophy ratio of the future remnant liver (FRL) after PVE than patients without SOS (16.8 ± 24.0 vs 55.6 ± 32.5; P < 0.001). Multivariate logistic regression analysis revealed that SOS was an independent factor predicting lower FRL hypertrophy after PVE (Δ% FRL <20: hazard ratio 31.7, 95% confidence interval 2.84-355.12; P = 0.005). The incidence of postoperative transient liver failure after the 2nd-stage hepatectomy in patients presenting with SOS was higher than that in those without SOS, but the difference did not reach significance (25.0% vs 4.0%; P = 0.052). Steatohepatitis was confirmed at the 1st- and 2nd-stage hepatectomy in 6 (14.3%) and 3 (6.7%) patients, respectively.

CONCLUSION

Sinusoidal obstruction syndrome inhibits FRL hypertrophy after PVE and induces postoperative liver failure. Therefore, an alternative strategy is needed to perform TSH safely in the presence of SOS.

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.

Outcomes of simultaneous and delayed resections of synchronous colorectal liver metastases

BACKGROUND

The optimal strategy for the treatment of synchronous colorectal liver metastases has not been established yet. In this study, we present the outcomes and survival rates of the patients who underwent simultaneous or delayed resections.

METHODS

We performed a retrospective analysis of liver resections in our institution between 1997 and 2006.

RESULTS

Among the 89 patients presenting with synchronous colorectal liver metastases, 28 underwent simultaneous and 61 underwent delayed resection. Age, sex and localization of the primary tumour were similar in the 2 groups. Duration of surgery and hospital stay were longer in the simultaneous resection group, and blood loss was also greater in this group. However, these factors did not influence the frequency of complications, which did not differ between the groups. When we included data from initial colectomy, these differences were either not significant or in favour of synchronous resection. In the delayed resection group, colon resection was performed in different hospitals. The 1-, 3- and 5-year survival rates were 78%, 70% and 45%, respectively, in the simultaneous and 88%, 55% and 38%, respectively, in the delayed resection groups.

CONCLUSION

In select patients, the risk of simultaneous resection of synchronous colorectal liver metastases is comparable to delayed resection, and increases in blood loss and operating time associated with simultaneous resections do not have a negative influence on long-term outcome. Positive outcomes of simultaneous liver resections in our study could be a result of good patient selection or experience with oncological liver surgery.

Long-term survival after liver resection for colorectal liver metastases in patients with hepatic pedicle lymph nodes involvement in the era of new chemotherapy regimens

SUMMARY AND BACKGROUND

Survival benefit, in patients with colorectal liver metastases (CLM) and hepatic pedicle lymph nodes (HPLN) involvement along the common hepatic artery and celiac axis (area 2 or distal) has not been observed. However, these results are based on historical series, using suboptimal chemotherapy drugs.

OBJECTIVE

The aim of the present study is to investigate the impact of HPLN involvement on survival after resection for CLM in the era of the new chemotherapy regimens.

PATIENTS AND METHODS

Between January 2000 and June 2006, 45 high risk consecutive patients presenting all with pathologically proven HPLN metastases were identified from a prospectively maintained database. Prognostic factors for survival and recurrence were analyzed.

RESULTS

The mean follow-up was 25.5 months. HPLN involvement was located in area 1 in 17 patients, area 2 in 10, and both area 1 and 2 were involved in 18 patients. The overall 3- and 5-year survival rates were 29.7% and 17.3%, respectively. The median survival was 20.9 months. Three patients are alive and disease-free at 32.4, 33.5, and 46.9 months, respectively. The multivariate analysis showed that the carcinoembryonic antigen blood level before hepatectomy, a curative intent R0 liver resection, the ratio of involved/total resected HPLN, and an adjuvant chemotherapy after liver resection were independent risk factors for overall survival.

CONCLUSIONS

This study showed that the localization of HPLN metastases within area 1 or 2 does not anymore affect survival after CLM resection. Furthermore, this study provides a support to perform a routine HPLN dissection in high risk patients undergoing liver resection for CLM to recognize HPLN involvement, to improve the ratio of involved/total resected lymph nodes, and to assign the patients for an adjuvant chemotherapy. Finally, these results indicate that curative intent R0 liver resection with HPLN dissection can offer the only potential cure for patients with CLM who present with HPLN involvement.

Present status and future perspectives of preoperative portal vein embolization

BACKGROUND

Portal vein embolization (PVE) has been gaining increasing acceptance before major hepatectomy. This review presents the application, outcome, and recent developments of PVE.

METHODS

After a systematic search of "portal vein embolization" in PubMed, we reviewed and retrieved articles written in English related to PVE. There were no other criteria for exclusion of published information pertaining to this topic.

RESULTS

Hypertrophy of future liver remnants with PVE in patients with hepatobiliary malignancy results in fewer complications and shorter hospital stays after major hepatectomy, and add to the pool of candidates for surgical treatment. Some new techniques, such as sequential hepatic artery-portal vein embolization and PVE with stem cell administration, have showed a promising clinical future.

CONCLUSIONS

PVE has achieved significant improvement in the outcome of major hepatectomy, and has enlarged the candidate pool of liver resection as well. Future study is needed to identify the precise mechanism of liver regeneration after PVE.

The management of colorectal liver metastases: Expanding the role of hepatic resection in the age of multimodal therapy

Colorectal cancer (CRC) caused nearly 204,000 deaths in Europe in 2004. Despite recent advances in the treatment of advanced disease, which include the incorporation of two new cytotoxic agents irinotecan and oxaliplatin into first-line regimens, the concept of planned sequential therapy involving three active agents during the course of a patient's treatment and the integrated use of targeted monoclonal antibodies, the 5-year survival rates for patients with advanced CRC remain unacceptably low. For patients with colorectal liver metastases, liver resection offers the only potential for cure. This review, based on the outcomes of a meeting of European experts (surgeons and medical oncologists), considers the current treatment strategies available to patients with CRC liver metastases, the criteria for the selection of those patients most likely to benefit and suggests where future progress may occur.

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.

Management of hepatic metastasis from colorectal cancers: an update

Approximately 50%-60% of patients with colorectal cancers will develop liver lesions in their life span. Despite the potential of surgical resection to provide long-term survival in this subset of patients, only 15%-20% are found to be resectable. The introduction of new neoadjuvant chemotherapeutic agents and the expanding criteria of resection have enhanced the overall 5-year survival from 30% to 60% in the past decade. The use of technical innovations such as staged resection; portal vein embolization, and repeat resection have allowed higher resection rates in patients with bilobar disease. Extrahepatic primary and liver-exclusive recurrent disease no longer represent an absolute contraindication to resection. The role of regional therapy using hepatic arterial infusion is being redefined for liver-exclusive unresectable disease. Adjuvant chemotherapy in combination with regional therapies is being looked at from fresh perspectives. Ablative approaches have gained a firm role both as an adjunct to surgical resection and in the management of patients who are not surgical candidates. Overall, the management of hepatic metastasis from colorectal cancers requires a multimodal approach.

Bilobar colorectal liver metastases: treatment options

Although prospective, randomized clinical trials never have been conducted, retrospective and comparative studies strongly indicate that hepatic resection is the only available treatment that allows long-term survival in colorectal carcinoma that has metastasized to the liver. Unfortunately, curative resection can be performed in less than 25% of the patients. Ten years ago, hepatic resection was contraindicated in case of multiple or bilobar nodules. Currently, the trend is to be more aggressive and to increase the indications for surgical resection with the development of new strategies using a multidisciplinary approach.

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.

Preoperative contralateral portal vein embolization before major hepatic resection is a safe and efficient procedure: a large single institution experience

BACKGROUND

The aim of this study was to report the results of preoperative contralateral portal vein embolization (PVE) performed in a single institution.

METHODS

Between January 1997 and March 2006, 146 patients requiring a right or extended right hepatectomy for primary or secondary liver tumors underwent contralateral PVE when the future remnant liver volume (FRL) was less than 30% of total liver. Liver volumes and hepatic function were evaluated before and after PVE.

RESULTS

Contralateral PVE was performed successfully in 145 patients. In one patient, the catheterization of the left portal branch failed. Complications occurred in 14 patients (10%) including a transitory fever (n = 9), a parenchymal hematoma (n = 1), a mild hemoperitoneum (n = 1), a mesenterico-portal venous thrombosis (n = 1), a pulmonary embolism (n = 1) and a systemic sepsis (n = 1). The prothrombin ratio and the platelet count were significantly lower 3 days after PVE. Insufficient hypertrophy of the FRL was observed in 8 patients, malignant disease progression in 15, and both insufficient hypertrophy and disease progression in 4. The hypertrophy rate of the FRL 4 to 8 weeks after PVE was 47.7 +/- 31.9%. Pathological type of the liver tumor, cirrhosis, diabetes mellitus, and chemotherapy did not affect the volume of the left liver hypertrophy. However, the time required to achieve an adequate liver hypertrophy was significantly shorter in patients with normal liver. One-hundred and fourteen patients (78.6%) subsequently underwent hepatic resection.

CONCLUSIONS

The results suggest that contralateral PVE is a safe and efficient procedure inducing adequate hypertrophy of the FRL before major liver resection.

[Colorectal liver metastases. Neoadjuvant chemotherapy: aspects of medical and surgical oncology]

Colorectal liver metastases are detected in 15-20% of patients at the time of diagnosis of the primary tumor, they develop in an additional 20-30% of patients during further course of the disease. Radical resection enables 5-year survival rates of 30-50%. Resectability may be increased by surgical techniques including two-stage hepatectomy and portal vein embolization. Furthermore, modern chemotherapy including various combinations of oxaliplatin, irinotecan, bevacizumab, and cetuximab has led to secondary resectability correlating to response rates which may be up to 80%. Changes of hepatic histology such as sinusoidal obstruction (e.g. following oxaliplatin) or steatohepatitis (e.g. following irinotecan) have been described. Individually, this may increase the risk of subsequent liver resection. As of today the role of neoadjuvant chemotherapy for resectable lesions has not been definitively confirmed.

Liver resection for colorectal liver metastasis

At some point in the natural course of colorectal cancer up to 50% of patients will develop metastasis to the liver. Historically only 20% of these patients would have to be deemed resectable, with an intent to cure, at the time of presentation. But with recent improvements in cross-sectional imaging, chemotherapeutic agents and advances in the techniques of surgical resection the emphasis of resection has now changed to 'who is not resectable' as opposed to 'who is resectable'. There are few contraindications to liver resection on the proviso that the patient is fit enough. As a result of this paradigm shift, 5 year survival rates are approaching 60%. Historically liver resection was perceived as a formidable operation but now liver resection for CRLM is safe and specialist centres are reporting mortality rates of less than 1%. This review briefly covers the standard techniques currently employed and some of the recent innovations being developed to improve resectability.

Modern multimodality approach to hepatic colorectal metastases: solutions and controversies

Hepatic resection for colorectal metastases, limited to the liver, has become the standard of care, and currently remains the only potentially curative therapy. Numerous single institutional reports have demonstrated long-term survival and there are no other treatment options that have shown a survival plateau. However, curative resection is possible in less than 25% of those patients with disease limited to the liver, which translates into only 5-10% of the original group developing colorectal cancer. To increase the number of patients who could benefit from hepatic resection, the last decade has seen considerable effort being directed towards novel approaches to permit curative hepatic resection such as: neoadjuvant systemic and regional chemotherapy, pre-operative portal vein embolization for hypertrophy of future liver remnant, staged hepatic resection and radio frequency ablation combined with resection for addressing multiple bilobar metastases. This article reviews development of these innovative multidisciplinary modalities and the aggressive surgical approach that has been adopted to extend the frontiers of surgical therapy for colorectal hepatic metastases.