Indications for portal vein embolization combined with major hepatic resection for advanced-stage hepatocellular carcinomas. A preliminary clinical study

Systematic Reviews and Meta-Analyses of Portal Vein Embolization, Associated Liver Partition and Portal Vein Ligation, and Radiation Lobectomy Outcomes in Hepatocellular Carcinoma Patients

PURPOSE OF REVIEW

To understand portal vein embolization (PVE), associated liver partition and portal vein ligation (ALPPS) and radiation lobectomy (RL) outcomes in hepatocellular carcinoma (HCC) patients. Systematic reviews of future liver remnant (FLR) percent hypertrophy, proportion undergoing hepatectomy and proportion with major complications following PVE, ALPPS, and RL were performed by searching Ovid MEDLINE, Ovid EMBASE, The Cochrane Library, and Web of Science. Separate meta-analyses using random-effects models with assessment of study heterogeneity and publication bias were performed whenever allowable by available data.

RECENT FINDINGS

Of the 10,616 articles screened, 21 articles with 636 subjects, 4 articles with 65 subjects, and 4 articles with 195 subjects met the inclusion criteria for systematic reviews and meta-analyses for PVE, ALPPS, and RL, respectively. The pooled estimate of mean percent FLR hypertrophy was 30.9% (95%CI: 22-39%, Q = 4034.8, p < 0.0001) over 40.3 +/- 26.3 days for PVE, 54.9% (95%CI: 36-74%, Q = 73.8, p < 0.0001) over 11.1 +/- 3.1 days for ALPPS, and 29.0% (95%CI: 23-35%, Q = 56.2, p < 0.0001) over 138.5 +/- 56.5 days for RL. The pooled proportion undergoing hepatectomy was 91% (95%CI: 83-95%, Q = 43.9, p = 0.002) following PVE and 98% (95%CI: 50-100%, Q = 0.0, p = 1.0) following ALPPS. The pooled proportion with major complications was 5% (95%CI: 2-10%, Q = 7.3, p = 0.887) following PVE and 38% (95%CI: 18-63%, Q = 10.0, p = 0.019) following ALPPS. Though liver hypertrophy occurs following all three treatments in HCC patients, PVE balances effective hypertrophy with a short time frame and low major complication rate.

Management of Hepatocellular Carcinoma in Cirrhotic Patients with Portal Hypertension: Relevance of Hagen-Poiseuille's Law

BACKGROUND

Hepatic decompensation in cirrhosis heralds an accelerated course with poor survival. An increase in hepatic venous pressure gradient (HVPG), rather than surrogate tests of liver function, appears to be the sole predictor of decompensation after surgical resection. We propose that hepatic sinusoidal walls become less elastic as cirrhosis progresses. Decompensation signals the development of increased vessel wall rigidity. The pressure-flow characteristics then become subject to Hagen-Poiseuille's law, which applies only to rigid, cylindrical vessels. Thereafter, HVPG rises exponentially (by a factor inversely proportional to the fourth power of the net radius of functional sinusoidal vessels, 1/r(4), at any given hepatic blood flow rate. This review attempts to correlate liver stiffness, risk of decompensation and outcomes from hepatocellular carcinoma (HCC) in patients with cirrhosis.

SUMMARY

We compare the complexity of autoregulation in the normal elastic liver, which has a unique dual blood supply, with that in the rigid cirrhotic liver. We also review, in the context of background liver cirrhosis, the management of HCC which is in essence, a solid mass of unorganized cells that exacerbates liver stiffness. We discuss the differential effects of various therapeutic modalities such as liver transplantation, loco-regional therapy and drugs on HCC outcomes, based on their effects on HVPG.

KEY MESSAGES

Increased hepatic artery supply, or the hepatic artery buffer response, may be the only available method for autoregulation or maintenance of hepatic blood flow in the cirrhotic liver. In HCC, loco-regional therapies, including partial resection of the cirrhotic liver, can exacerbate portal hypertension by increasing blood flow within the remnant organ. We conclude that studies of HVPG reduction as part of HCC management may be beneficial and are warranted.

Preoperative portal venous and hepatic arterial embolization of tumor

Although the goal of embolization is usually to create therapeutic ischemia or hemostasis without surgery, the rationale for preoperative embolotherapy is different in several respects. First, the aim is to prepare patients for definitive surgical resection rather than cure or palliation, and, thus, the goals and expectations are limited and defined by close communication between the interventionalist and the surgeon. Second, when considering segmental resection, the normal liver should be protected from procedural damage. Third, the search for extrahepatic disease is crucial for these patients because resection is typically abandoned in favor of alternative therapies for patients with systemic disease. Finally, intraoperative ultrasound should always be considered to survey the future liver remnant for unsuspected small tumors and allow ablation of these lesions to maximize the success of partial hepatectomy. This article describes preoperative hepatic arterial and portal venous embolization in patients with or without cirrhosis complicated by tumors judged eligible for surgical resection or orthotopic liver transplantation (OLT). Each type of embolization will be reviewed in terms of indications and contraindications, technique, and complications. Finally, the outcomes will be evaluated in terms of morbidity, mortality, and tumor recurrence rates.

Sequential transcatheter arterial chemoembolization and portal vein embolization versus portal vein embolization only before major hepatectomy for patients with hepatocellular carcinoma

PURPOSE

To evaluate the safety and efficacy of sequential transcatheter arterial chemoembolization (TACE) and portal vein embolization (PVE) prior to surgery in hepatocellular carcinoma (HCC) patients and to compare the clinical outcome of the combined procedure with that of a matched group of patients undergoing PVE alone.

PATIENTS AND METHODS

From 1997 to 2008, 135 patients with HCC underwent sequential TACE and PVE (n = 71) or PVE alone (n = 64) before right hepatectomy. PVE was performed mean 1.2 months after TACE. In both groups, computed tomography (CT) and liver volumetry were performed before and 2 weeks after PVE to assess degree of left lobe hypertrophy.

RESULTS

Baseline patient and tumor characteristics were similar in the two groups. After PVE, the chronological changes of liver enzymes were similar in the two groups. The mean increase in percentage future liver remnant (FLR) volume was higher in the TACE + PVE group (7.3%) than in the PVE-only group (5.8%) (P = 0.035). After surgery, incidence of hepatic failure was higher in the PVE-only group (12%) than in the TACE + PVE (4%) group (P = 0.185). Overall (P = 0.028) and recurrence-free (P = 0.001) survival rates were significantly higher in the TACE + PVE group than in the PVE-only group.

CONCLUSION

Sequential TACE and PVE before surgery is a safe and effective method to increase the rate of hypertrophy of the FLR and leads to longer overall and recurrence-free survival in patients with HCC.

Portal vein embolization: rationale, outcomes, controversies and future directions

Portal vein embolization (PVE) is now considered the standard of care to improve safety for patients undergoing extensive hepatectomy with an anticipated small future liver remnant (FLR). PVE is used to induce contralateral liver hypertrophy in preparation for major liver resection. Optimal patient selection is essential to maximize the clinical benefits of PVE. Computed tomography volumetry is used to calculate a standardized FLR and determine the need for preoperative PVE. Percutaneous PVE can be performed via the transhepatic ipsilateral or contralateral approaches, depending on operator preference. Several different embolic agents are available to the interventional radiologist, all with similar effectiveness in inducing hypertrophy. When an extended hepatectomy is planned, right PVE should include segment 4, in order to maximize FLR hypertrophy. Multiple studies have demonstrated the beneficial outcomes of PVE in both patients with healthy livers and with underlying liver diseases. Novel improvements to PVE should expand its scope to patients who were previously not candidates for the procedure.

Preoperative portal vein embolization for major liver resection: a meta-analysis

INTRODUCTION

Preoperative portal vein embolization (PVE) is used clinically to prevent postoperative liver insufficiency. The current study examined the impact of portal vein embolization on liver resection.

METHOD

A comprehensive Medline search to identify all registered literature in the English language on portal vein embolization. Meta-analysis was performed to assess the result of PVE and its impact on major liver resection.

RESULT

A total of 75 publications met the search criteria but only 37 provided data sufficiently enough for analysis involving 1088 patients. The overall morbidity rate for PVE was 2.2% without mortality. Four weeks following PVE, 85% patients underwent the planned hepatectomy (n = 930). Twenty-three patients had transient liver failure following resection after PVE (2.5%) but 7 patients developed acute liver failure and died (0.8%). The reason for nonresection following PVE (n = 158, 15%) included inadequate hypertrophy of remnant liver (n = 18), severe progression of liver metastasis (n = 43), extrahepatic spread (n = 35), refusal to surgery (n = 1), poor general condition (n = 1), altered treatment to transcatheter artery embolization or chemotherapy (n = 24), complete remission after treatment with 3 cycles of fluoracil and interferon alpha in a patient with hepatocellular carcinoma (n = 1), incomplete pre- or postembolization scanning (n = 8). Of those who underwent laparotomy without resection, (n = 27) reasons included intraoperative finding of peritoneal dissemination (n = 15), portal node metastasis (n = 2), severe invasion of the tumor to the hepatic artery and portal vein (n = 1), and gross tumoral extension precluding curative resection (n = 9). Two techniques were used for portal vein embolization: percutaneous transhepatic portal embolization, (PTPE) and transileocolic portal embolization, (TIPE). The increase in remnant liver volume was much greater in PTPE than TIPE group (11.9% vs. 9.7%; P = 0.00001). However, the proportion of patients who underwent resection following PVE was 97% in TIPE and 88% PTPE, respectively (P = <0.00001). Although there was no significant difference in patients who had major complications post-PVE, the rate for minor complications was significantly higher among patients who had PTPE (53.6% vs. 0%, P = <0.0001).

CONCLUSION

PVE is a safe and effective procedure in inducing liver hypertrophy to prevent postresection liver failure due to insufficient liver remnant.

Preventive effect of regional radiotherapy with phosphorus-32 glass microspheres in hepatocellular carcinoma recurrence after hepatectomy

AIM

To evaluate the preventive effects of phosphorus-32 glass microspheres (P32-GMS) in the recurrence of massive hepatocellular carcinomas (HCCs) after tumor resection.

METHODS

Twenty-nine patients with massive HCCs received local P32-GMS implantation after liver tumors were removed, while the other 38 patients with massive HCCs were not treated with P32-GMS after hepatectomies. The radioactivity of the blood, urine and liver were examined. The complications, HCC recurrence and overall survival rates in the patients were analyzed.

RESULTS

P32-GMS implanted in the liver did not cause systemic absorption of P32. There were no significant differences of postoperative complications between the patients with and without P32-GMS treatment. The short-term (six months and 1 year) and long-term (2, 3 and over 3 years) recurrence rates in patients who received P32-GMS radiotherapy were significantly decreased, and the overall survival rates in this group were significantly improved.

CONCLUSION

P32-GMS implantation in the liver can significantly decrease the postoperative recurrence and improve the overall survival in HCCs patients after hepatectomy. This therapy may provide an innovative method in prevention of HCC recurrence after operation.

Sequential arterial and portal vein embolizations before right hepatectomy in patients with cirrhosis and hepatocellular carcinoma

BACKGROUND

Selective transarterial chemoembolization (TACE) and portal vein embolization (PVE) could improve the rate of hypertrophy of the future liver remnant (FLR) in patients with chronic liver disease. This study evaluated the feasibility and efficacy of this combined procedure.

METHODS

Between November 1998 and October 2004, 36 patients with cirrhosis and hepatocellular carcinoma underwent right hepatectomy after PVE. Additional TACE preceded PVE by 3-4 weeks in 18 patients (TACE+PVE group) and the remaining 18 patients had PVE alone (PVE group).

RESULTS

PVE was well tolerated in all patients. The mean increase in percentage FLR volume was significantly higher in the TACE+PVE group than in the PVE group (mean(s.d.) 12(5) versus 8(4) percent; P=0.022). The rate of hypertrophy was more than 10 percent in 12 patients in the TACE+PVE group and in five who had PVE alone (P=0.044). Duration of surgery, blood loss, incidence of liver failure and mortality (two patients in each group) were similar in the two groups. None of the 17 patients with an increase in FLR volume of more than 10 percent died, whereas there were four deaths among 19 patients with a smaller increase. The incidence of complete tumour necrosis was significantly higher in the TACE+PVE group (15 of 18 versus one of 18; P<0.001), with a higher 5-year disease-free survival rate (37 versus 19 percent; P=0.041).

CONCLUSION

Sequential TACE and PVE before operation increases the rate of hypertrophy of the FLR and leads to a high rate of complete tumour necrosis associated with longer recurrence-free survival.

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Portal Vein Embolization with N-Butyl Cyanoacrylate before Partial Hepatectomy in Patients with Hepatocellular Carcinoma and Underlying Cirrhosis or Advanced Fibrosis

PURPOSE

To describe the safety, complications, and liver regeneration associated with the left liver after embolization of the right portal vein (PV) in patients with hepatocellular carcinoma (HCC) developed in the setting of advanced liver fibrosis and cirrhosis.

MATERIALS AND METHODS

Forty patients (31 men, nine women; mean age, 62 years) with HCC underwent PV embolization over a 4-year period. Embolization was performed from a left PV percutaneous access with use of n-butyl cyanoacrylate (NBCA) mixed with iodized oil. Computed tomography (CT) volumetry was performed before and 1 month after PV embolization to measure the left lobe volume as well as the functional liver ratio defined by the ratio between the left lobe and the total liver volume minus tumoral volume. PV pressure and liver enzyme levels were compared before and 1 month after the procedure and complications were registered. Factors potentially affecting regeneration (age, sex, diabetes, chemoembolization, functional liver ratio before PV embolization, and Knodell histologic score) were evaluated by one-way and stepwise regression analysis.

RESULTS

PV embolization could be achieved successfully in all cases. Two patients had partial PV thrombosis on the 1-month follow-up CT and two patients developed transient ascites after PV embolization. The left lobe volume increase was 41% +/- 32% after PV embolization and the functional liver ratio increased from 28% +/- 10% to 36% +/- 10% (P < .0001). Hypertrophy of the left lobe was greater in patients with a low functional liver ratio before PV embolization and those with an F3 fibrosis score. Other factors had no influence on left lobe regeneration.

CONCLUSION

PV embolization with use of NBCA is feasible in patients with advanced fibrosis and cirrhosis. Hypertrophy of the left lobe of the liver after PV embolization has a statistically significant correlation with lower functional liver ratio and lower degrees of fibrosis.

Portal vein embolization in preparation for major hepatic resection: evolution of a new standard of care

Portal vein (PV) embolization (PVE) is gaining acceptance in the preoperative management of patients selected for major hepatic resection. PVE redirects portal blood flow to the intended liver remnant to induce hypertrophy of the nondiseased portion of the liver and thereby reduce complications and shorten hospital stays after resection. This article reviews the rationale and existing literature on PVE, including the mechanisms of liver regeneration, the pathophysiology of PVE, the imaging techniques used to measure liver volumes and estimate functional hepatic reserve, and the technical aspects of PVE, including approaches and embolic agents used. In addition, the indications and contraindications for performing PVE in patients with and without chronic liver disease and the multidisciplinary approach required for the treatment of these complex cases are emphasized.

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Total vascular exclusion technique for resection of hepatocellular carcinoma

AIM: To improve the low resection rate, poor prognosis and to control the massive hemorrhage during operation, total vascular exclusion (TVE) technique was used in hepatectomies of advanced and complicated hepatocellular carcinomas (HCCs).

METHODS: Five hundred and thirty patients with HCCs were admitted in our hospital. They were divided into TVE technique group (group A: n = 78), Pringle maneuver method group (group B: n = 176) and unresectable group (group C: n = 276). The clinical, operative, pathological parameters and outcome of the patients were statistically evaluated.

RESULTS: Group A had a significantly higher resection rate than group B (accounting for 47.92% and 33.21% respectively). There was no significant difference in blood loss, blood transfusion and perioperative mortality between groups A and B. Both groups had the similar median disease free survival time (14.6 vs 16.3 months) and 1 year survival rate (92.9% vs 95.5%). The TVE group had a medial survival time of 40.5 months and its 5-year survival rate was 34.6%.

CONCLUSION: As compared with Pringle maneuver method, the total vascular exclusion is a safe and effective technique to increase the total resection rate of advanced and complicated HCCs.

Hepatocellular carcinoma in a low-incidence region. Surgical perspectives

BACKGROUND/AIMS

To study the characteristics and outcome of patients with hepatocellular carcinoma in a low-incidence region.

METHODS

98 patients with hepatocellular carcinoma who had been referred to the Surgical Department, National Hospital, Oslo, between 1981 and 1999 were studied retrospectively. Tumour size, prevalence of cirrhosis, serum alpha-fetoprotein concentration, rate of resection, type of resection and survival were analysed.

RESULTS

19% (19/98) of the patients had cirrhosis of varying aetiology. Median tumour size was 10 cm. alpha-Fetoprotein was normal in 46% of the patients. Hepatic resection was performed in 30 (31%) patients and 77% of the resections were major (more than 2 segments). Abdominal exploration was done in 33 patients and liver transplantation in 6 patients. No surgical intervention was made in 31 patients. Five-year actuarial survival in resected patients was 24%. Median survival of non-resected patients was 3.3 months.

CONCLUSION

The patient characteristics in this study differ from patient cohorts with hepatocellular carcinoma in other geographical areas. The main differences are large tumour size, low prevalence of the disease, and diverse aetiology of cirrhosis.

Indications for and limitations of portal vein embolization before major hepatic resection for hepatobiliary malignancy

Portal vein embolization is a promising adjunctive tool in liver surgery; however, the understanding of liver regeneration and PVE is still in its infancy. Refinement in patient selection criteria and methods to evaluate hepatic hypertrophy and function should increase the potential indications for PVE and expand the field of major liver surgery.