Standardized measurement of the future liver remnant prior to extended liver resection: methodology and clinical associations

Liver resective surgery: a multivariate analysis of postoperative outcome and complication

INTRODUCTION

Notwithstanding technical advances and high experience of liver resection of specialized centers, the rate of complications after surgical resection could be high. In this study, we analyzed causes and foreseeable risk factors linked to postoperative morbidity on the ground of data derived from a single center surgical population.

MATERIALS AND METHODS

From September 1989 to March 2005, 134 consecutive patients had liver resection for Hcc and 153 consecutive patients with liver metastasis (derived from either colorectal cancer or noncolorectal cancer) at our department. We performed 22 major hepatectomy, 20 left hepatectomy, 14 trisegmentectomy, 77 bisegmentectomy and/or left lobectomy, 74 segmentectomy, and 80 wedge resection.

RESULTS

In-hospital mortality rate was 4.5%, about 7% in Hcc cases and 2.6% in liver metastasis. Morbidity rate was 47.7%, caused by the rising of ascites (10%), temporary impairment liver function (19%), biliary fistula (6%), hepatic abscess (25%), hemoperitoneum (10%), and pleural effusion (30%) sometimes combined each other. Some variables, associated with the technical aspects of surgical procedure, are responsible of the rising of complication as: Pringle maneuver length of more than 20 minutes (p=0.001); the type of liver resection procedure [major hepatectomy (p=0.02), left hepatectomy (p=0.04), trisegmentectomy (p=0.04), bisegmentectomy and/or left lobectomy (p=0.04)]; and the request of an amount of blood transfusion of more than 600 cc (p=0.04). Also, both liver dysfunction, in particular Child A vs B and C (p=0.01), and histopathological grading (p=0.01) are associated with a high rate of postsurgical complication in Hcc cases.

CONCLUSION

We make the following recommendations: every liver resection should be planned after intraoperative ultrasonography, anatomical surgical procedure should be preferred instead of wedge resection, and modern devices should be used, like Argon Beam and Ligasure dissector, to reduce the incidence of both intraoperative and postoperative bleeding and biliary leakage.

Association between biliary complications and technique of hilar division (extrahepatic vs. intrahepatic) in major liver resections

BACKGROUND

Division of major vascular and biliary structures during major hepatectomies can be carried out either extrahepatically at the porta hepatic or intrahepatically during the parenchymal transection. In this retrospective study we test the hypothesis that the intrahepatic technique is associated with less early biliary complications.

METHODS

150 patients who underwent major hepatectomies were retrospectively allocated into an intrahepatic group (n = 100) and an extrahepatic group (n = 50) based on the technique of hilar division. The two groups were operated by two different surgical teams, each one favoring one of the two approaches for hilar dissection. Operative data (warm ischemic time, operative time, blood loss), biliary complications, morbidity and mortality rates were analyzed.

RESULTS

In extrahepatic patients, operative time was longer (245 +/- 50 vs 214 +/- 38 min, p < 0.05) while the overall complication rate (55% vs 52%), hospital stay (13 +/- 7 vs 12 +/- 4 days), bile leak rate (22% vs 20%) and mortality (2% vs 2%) were similar compared to intrahepatic patients. However, most (57%) bile leaks in extrahepatic patients were grade II (leaks that required non-operative interventional treatment, while most (70%) leaks in the intrahepatic group were grade I (leaks that resolved and presented two injuries (4%) of the remaining bile ducts (p < 0.05).

CONCLUSION

Intrahepatic hilar division is as safe as extrahepatic hilar division in terms of intraoperative blood requirements, morbidity and mortality. The extrahepatic technique is associated with more severe bile leaks and biliary injuries.

Liver resection in the treatment of hepatocellular carcinoma

Hepatocellular carcinoma is a leading cause of cancer death worldwide. Liver resection and liver transplantation remain the only options for cure. Since the indications for orthotopic liver transplantation are limited, partial liver resection is the more common treatment. Recently, indications for liver resection have been expanded and there have been advances in the associated surgical techniques. This review describes the state-of-the-art of liver resection for hepatocellular carcinoma. Topics covered include: new indications, such as treatment of large tumors, bilobar tumors and those associated with vascular invasion; preoperative assessment of liver function; and surgical strategies. An overview of the most common staging systems, which are useful in predicting prognosis after liver resection for hepatocellular carcinoma, is given.

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Downstaging colorectal liver metastases by concomitant unilateral portal vein ligation and selective intra-arterial chemotherapy

BACKGROUND

Although selective intrahepatic arterial chemotherapy successfully downstaged irresectable colorectal liver metastases in a previous study, curative resection was rarely possible, as the remnant healthy liver volume was inadequate. This pilot study evaluated the efficacy of concomitant unilateral portal vein ligation and selective intrahepatic arterial chemotherapy in downstaging such tumours.

METHODS

The study included 11 patients with irresectable colorectal liver metastases. Selective intrahepatic arterial chemotherapy was delivered using a subcutaneous pump, and each patient underwent concomitant unilateral portal vein ligation of the hemiliver judged to have the higher tumour load. Chemotherapy involved serial administration of floxuridine for 2 weeks every 4 weeks.

RESULTS

All patients developed significant atrophy of the hemiliver subjected to portal vein ligation and contralateral hypertrophy. There was no increase in tumour load within 6 months of therapy, and the load decreased by 60 per cent in the hemiliver ipsilateral to the ligated vein. At 3 months, six of 11 patients showed a significant response to chemotherapy. In four patients, downstaging allowed curative resection after only three cycles of chemotherapy. These patients survived at least 20 months afterwards.

CONCLUSION

Combined unilateral portal vein ligation and selective intrahepatic arterial chemotherapy produced substantial atrophy of the ipsilateral hemiliver along with contralateral hypertrophy, without increased tumour growth in the regenerating hemiliver.

Chemotherapy regimen predicts steatohepatitis and an increase in 90-day mortality after surgery for hepatic colorectal metastases

PURPOSE

Chemotherapy before resection of hepatic colorectal metastases (CRM) may cause hepatic injury and affect postoperative outcome.

PATIENTS AND METHODS

Four hundred six patients underwent hepatic resection of CRM between 1992 and 2005. Pathologic review of the nontumorous liver was performed using established criteria for steatosis, steatohepatitis, and sinusoidal injury. The effect of chemotherapy and liver injury on perioperative outcome was analyzed.

RESULTS

One hundred fifty-eight patients (38.9%) received no preoperative chemotherapy, whereas 248 patients (61.1%) did. The median duration of chemotherapy was 16 weeks (range, 2 to 70 weeks). Chemotherapy consisted of fluoropyrimidine-based regimens (fluorouracil [FU] alone, 15.5%; irinotecan plus FU, 23.1%; and oxaliplatin plus FU, 19.5%) and other therapy (3.0%). On pathologic analysis, 36 patients (8.9%) had steatosis, 34 (8.4%) had steatohepatitis, and 22 (5.4%) had sinusoidal dilation. Oxaliplatin was associated with sinusoidal dilation compared with no chemotherapy (18.9% v 1.9%, respectively; P < .001; odds ratio [OR] = 8.3; 95% CI, 2.9 to 23.6). In contrast, irinotecan was associated with steatohepatitis compared with no chemotherapy (20.2% v 4.4%, respectively; P < .001; OR = 5.4; 95% CI, 2.2 to 13.5). Patients with steatohepatitis had an increased 90-day mortality compared with patients who did not have steatohepatitis (14.7% v 1.6%, respectively; P = .001; OR = 10.5; 95% CI, 2.0 to 36.4).

CONCLUSION

Steatohepatitis is associated with an increased 90-day mortality after hepatic surgery. In patients with hepatic CRM, the chemotherapy regimen should be carefully considered because the risk of hepatotoxicity is significant.

Two hundred forty consecutive portal vein embolizations before extended hepatectomy for biliary cancer: surgical outcome and long-term follow-up

OBJECTIVE

To assess clinical benefit of portal vein embolization (PVE) before extended, complex hepatectomy for biliary cancer.

SUMMARY BACKGROUND DATA

Many investigators have addressed clinical utility of PVE before simple hepatectomy for metastatic liver cancer or hepatocellular carcinoma, but few have reported PVE before hepatectomy for biliary cancer due to the limited number of surgical cases.

METHODS

This study involved 240 consecutive patients with biliary cancer (150 cholangiocarcinomas and 90 gallbladder cancers) who underwent PVE before an extended hepatectomy (right or left trisectionectomy or right hepatectomy). All PVEs were performed by the "ipsilateral approach" 2 to 3 weeks before surgery. Hepatic volume and function changes after PVE were analyzed, and the outcome also was reviewed.

RESULTS

There were no procedure-related complications requiring blood transfusion or interventions. Of the 240 patients, 47 (19.6%) did not undergo subsequent hepatectomy. The incidence of unresectability was higher in gallbladder cancer than in cholangiocarcinoma (32.2% versus 12.0%, P < 0.005). The remaining 193 patients (132 cholangiocarcinomas and 61 gallbladder cancers) underwent hepatectomy with resection of the caudate lobe and extrahepatic bile duct (n = 187), pancreatoduodenectomy (n = 42), and/or portal vein resection (n = 63). Seventeen (8.8%) patients died of postoperative complications: mortality was higher in gallbladder cancer than in cholangiocarcinoma (18.0% versus 4.5%, P < 0.05); and it was also higher in patients whose indocyanine green clearance (KICG) of the future liver remnant after PVE was <0.05 than those whose index was >or=0.05 (28.6% versus 5.5%, P < 0.001). The 3- and 5-year survival after hepatectomy was 41.7% and 26.8% in cholangiocarcinoma and 25.3% and 17.1% in gallbladder cancer, respectively (P = 0.011). In 136 other patients with cholangiocarcinoma who underwent a less than 50% resection of the liver without PVE, a mortality of 3.7% and a 5-year survival of 27.6% were observed, which was similar to the 132 patients with cholangiocarcinoma who underwent extended hepatectomy after PVE.

CONCLUSIONS

PVE has the potential benefit for patients with advanced biliary cancer who are to undergo extended, complex hepatectomy. Along with the use of PVE, further improvements in surgical techniques and refinements in perioperative management are necessary to make difficult hepatobiliary resections safer.

Surgical treatment of liver metastases of colorectal cancer: Strategies and controversies in 2006

AIMS

To review the latest strategies and controversies in the surgical treatment of liver metastases of colorectal cancer systemically and comprehensively.

METHODS

A medline based literature search on relevant topics was performed in PubMed for key articles concerning the novel strategies and controversies in the management of liver metastases of colorectal cancer. Some information was obtained from 'Proc Am Soc Clin Oncol' published recently. The findings and discussions were related to our own experiences.

RESULTS

Although for well-indicated patients, a consensus has been reached that hepatic resection is the only management that could provide the patients curability, there still exist many controversies, such as the prognostic evaluation, contraindications to hepatic resection, treatment for synchronous liver metastases, the place of laparoscopic surgery, etc. Meanwhile, various strategies to improve the respectabilities are available, including neoadjuvant chemotherapy, portal vein embolization, two stage hepatectomy, and some locally ablative approaches. The current condition is difficult and sometimes confusing for a relevant surgeon when designing treatment protocols for more complex diseases.

CONCLUSION

As the advancing of the management of liver metastases of colorectal cancer, more patients will become candidates for and benefit from potentially curative surgical resections. Optimal effect could only be achieved when used in a manner tailored to the individual patient.

Survival after hepatic resection for colorectal metastases: a 10-year experience

BACKGROUND

Metastatic colorectal cancer is a major cause of cancer death in North America. Hepatic resection offers the potential for cure in selected patients. We report the long-term outcomes of patients who underwent hepatic resection for colorectal metastases over a 10-year period at a single hepatobiliary surgical oncology center.

METHODS

All patients who underwent liver resection for metastatic colorectal cancer between 1992 and 2002 were identified. Data were retrospectively obtained through chart review. Major outcome variables were disease-free survival and overall survival. Risk factors for disease recurrence and mortality were identified by multivariate analysis by using the Cox proportional hazard method.

RESULTS

A total of 423 hepatectomies were performed for metastatic colorectal cancer. Most operations (n = 276; 65%) were major (four or more segments) hepatectomies. Perioperative morbidity occurred in 74 (17%) patients. There were seven (1.6%) perioperative deaths. The disease-free survival at 1, 5, and 10 years was 64%, 27%, and 22%, respectively. The overall survival at 1, 5, and 10 years was 93%, 47%, and 28%, respectively. Multivariate analysis identified four negative predictive factors for overall survival (hazard ratio; 95% confidence interval): a positive surgical margin (2.9; 1.5-5.3), large metastases (>5 cm; 1.5; 1.1-2.0), multiple metastases (1.4; 1.1-1.9), and age >60 years (1.4; 1.1-1.9).

CONCLUSIONS

Hepatic resection for metastatic colorectal cancer is safe and provides good long-term overall survival rates of 47% at 5 years and 28% at 10 years. An aggressive approach is justified by the low operative mortality rate and good long-term survival, even in individuals with multiple bilobar metastases.

Interventional procedures involving portal vein circulation: a review

Rapid development of diagnostic radiological methods during recent decades has been followed by development of new interventional procedures involving portal circulation. The majority of these interventions were developed for treatment of patients with symptoms secondary to portal hypertension (PH). Interventions involving portal vein circulation have an established position in the treatment of PH and other diseases, and further development of these methods can be expected.

[Liver metastases from colorectal cancer. Is the practice of surgery based on the best clinical evidence possible?]

To date, surgical resection remains the only curative treatment for liver metastases from colorectal cancer. However, the evidence supporting this treatment is based on retrospective studies. The lack of level I clinical evidence has stimulated strong interest in identifying the factors predictive of recurrence, and even to use them to create clinical risk scores (assigning one point to each factor for poor prognosis), in which a higher score indicates a poorer prognosis. In the present review, we discuss all these factors, as well as the therapeutic alternatives that improve local disease control. Next, we review all the prospective randomized studies published on this topic, which mainly focus on adjuvant chemotherapy associated with curative surgery with negative margins, with the aim of validating or rejecting this treatment. Lastly, we include the algorithm of the University of California at San Francisco for surgery in liver metastases from colorectal cancer.

The "50-50 criteria" on postoperative day 5: an accurate predictor of liver failure and death after hepatectomy

OBJECTIVE

To standardize the definition of postoperative liver failure (PLF) for prediction of early mortality after hepatectomy.

SUMMARY BACKGROUND DATA

The definition of PLF is not standardized, making the comparison of innovations in surgical techniques and the timely use of specific therapeutic interventions complex.

METHODS

Between 1998 and 2002, 775 elective liver resections, including 69% for malignancies and 60% major resections, were included in a prospective database. The nontumorous liver was abnormal in 43% with steatosis >30% in 14%, noncirrhotic fibrosis in 43%, and cirrhosis in 12%. The impact of prothrombin time (PT) <50% and serum bilirubin (SB) >50 micromol/L on postoperative days (POD) 1, 3, 5, and 7 was analyzed.

RESULTS

The lowest PT level was observed on postoperative day (POD) 1, while the peak of SB was observed on POD 3. These 2 variables tended to return to preoperative values by POD 5. The median interval between hepatectomy and postoperative death was 15 days (range, 5-39 days). Postoperative mortality significantly increased in patients with PT <50% and SB >50 microml/L. The conjunction of PT <50% and SB >50 micromol/L on POD 5 was a strong predictive factor of mortality. In patients with significant morbidity, this "50-50 criteria" was met 3 to 8 days before clinical evidence of complications.

CONCLUSIONS

The association of PT <50% and SB >50 microml/L on POD 5 (the 50-50 criteria) was a simple, early, and accurate predictor of more than 50% mortality rate after hepatectomy. This criteria could be identified early enough, before clinical evidence of complications, for specific interventions to be applied in due time.

Liver failure following partial hepatectomy

While major liver resections have become increasingly safe due to better understanding of anatomy and refinement of operative techniques, liver failure following partial hepatectomy still occurs from time to time and remains incompletely understood. Observationally, certain high-risk circumstances exist, namely, massive resection with small liver remnants, preexisting liver disease, and advancing age, where liver failure is more likely to happen. Upon review of available clinical and experimental studies, an interplay of factors such as impaired regeneration, oxidative stress, preferential triggering of apoptotic pathways, decreased oxygen availability, heightened energy-dependent metabolic demands, and energy-consuming inflammatory stimuli work to produce failing hepatocellular functions.

Diagnostic value of measuring liver volume for detecting occult hepatic metastases from colorectal or gastric cancer

Some studies have shown reduced portal blood flow in patients with occult hepatic metastases, which may lead to decreased liver volume. A retrospective study was conducted in patients undergoing curative resection for colorectal (n = 63) or gastric (n = 52) cancer. The ratio of the preoperative computed tomography (CT)-estimated liver volume to the standard liver volume (CV/SV ratio) was calculated. The mean +/- SD CT-estimated liver volume was 858 +/-109 in 14 patients who subsequently developed hepatic metastases and 1173 +/- 230 ml in 101 patients without metastases (p < 0.0001). The CV/SV ratio was smaller in patients with metachronous hepatic metastases than in those without (0.78 +/- 0.08 vs. 1.02 + 0.13; p < 0.0001). The results suggest that the liver with occult metastases decreases in size before metastases develop that are detectable using conventional imaging techniques. The CV/SV ratio may be of value in detecting occult hepatic metastases from colorectal and gastric cancer.

Treatment for multiple bilobar liver metastases of colorectal cancer

BACKGROUND

Recent advances have extended indications for hepatectomy to include multiple bilobar colorectal liver metastases (CLM). Staging systems based on the biological malignancy of primary and metastatic tumors provide appropriate indications for hepatectomy in CLM. However, suitability for resection in patients with complex and extensive hepatic metastases is controversial.

METHODS

A medline search was performed to identify papers reporting the resection for CLM. Techniques, indication, and results were reviewed.

RESULTS

If the anticipated remnant liver volume is small (25-40% of total), suggesting a high risk of postoperative liver failure, portal vein embolization (PVE) is recommended prior to hepatectomy. However, curative resections are not always possible. Specifically in synchronous multiple bilobar CLM, two-stage hepatectomy, comprising bilateral hepatectomy and primary resection with or without PVE, can prevent growth of ipsilateral metastatic nodules in the remnant liver and reduce surgical risk. Several local ablation techniques can complement surgery if hepatic resection alone increases the risk of postoperative liver failure or is not curative. Chemotherapy combined with targeted treatment can suppress recurrence and extend indications for hepatectomy by reducing the size and number of primary irresectable tumors.

CONCLUSION

PVE or staged procedure combining with local ablation or neoadjuvant, downstaging or adjuvant therapies extends indications for hepatectomy to include multiple bilobar CLM. The 5-year survival rate for multiple bilobar CLM treated with alternating hepatectomy and chemotherapy is comparable to the values reported for single and hemilateral CLM.

The "50-50 criteria" on postoperative day 5: an accurate predictor of liver failure and death after hepatectomy

OBJECTIVE

To standardize the definition of postoperative liver failure (PLF) for prediction of early mortality after hepatectomy.

SUMMARY BACKGROUND DATA

The definition of PLF is not standardized, making the comparison of innovations in surgical techniques and the timely use of specific therapeutic interventions complex.

METHODS

Between 1998 and 2002, 775 elective liver resections, including 69% for malignancies and 60% major resections, were included in a prospective database. The nontumorous liver was abnormal in 43% with steatosis >30% in 14%, noncirrhotic fibrosis in 43%, and cirrhosis in 12%. The impact of prothrombin time (PT) <50% and serum bilirubin (SB) >50 micromol/L on postoperative days (POD) 1, 3, 5, and 7 was analyzed.

RESULTS

The lowest PT level was observed on postoperative day (POD) 1, while the peak of SB was observed on POD 3. These 2 variables tended to return to preoperative values by POD 5. The median interval between hepatectomy and postoperative death was 15 days (range, 5-39 days). Postoperative mortality significantly increased in patients with PT <50% and SB >50 microml/L. The conjunction of PT <50% and SB >50 micromol/L on POD 5 was a strong predictive factor of mortality. In patients with significant morbidity, this "50-50 criteria" was met 3 to 8 days before clinical evidence of complications.

CONCLUSIONS

The association of PT <50% and SB >50 microml/L on POD 5 (the 50-50 criteria) was a simple, early, and accurate predictor of more than 50% mortality rate after hepatectomy. This criteria could be identified early enough, before clinical evidence of complications, for specific interventions to be applied in due time.

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.

Prediction of the risk of hepatic failure in patients with portal vein invasion hepatoma after hepatic resection

AIM

Hepatic failure can develop after curative hepatectomy in patients with a hepatocellular carcinoma (HCC) invading the portal vein, because of cirrhosis and excessive tissue loss. This study aimed to identify the risk factors for hepatic failure in such patients.

METHOD

Forty patients with an HCC invading the portal vein underwent curative hepatectomy from January 1995 to June 2003. Eight patients developed hepatic failure and died within 3 months. Possible risk factors for this were analysed using univariate and multivariate regression. These included the liver function index, surgical blood loss, tumour pattern, portal hypertension, estimated residual liver volume measured by computed tomography (ERLV(CT)) and estimated residual liver volume using the indocyanine green (ICG) retention rate at 15 min (ERLV(ICG15)).

RESULTS

The ERLV(CT) smaller than the ERLV(ICG15) and presence of portal hypertension were independent risk factors for post-hepatectomy hepatic failure.

CONCLUSION

Having portal vein invasion HCC with portal hypertension or an ERLV(CT) less than an ERLV(ICG15) are significant predictors of post-hepatectomy hepatic failure. These factors are important considerations for patients with portal vein invasion HCC who could undergo curative hepatic resection.

Vascular occlusion to decrease blood loss during hepatic resection

BACKGROUND

Historically, the primary hazard with liver surgery has been intraoperative blood loss. This led to the refinement of inflow and outflow occlusive techniques. The utility of the different methods of inflow and outflow techniques for hepatic surgery were reviewed.

METHODS

A search of the English literature (Medline, Embase, Cochrane library, Cochrane clinical trials registry, hand searches, and bibliographic reviews) using the terms "liver," "hepatic," "Pringle," "total vascular exclusion," "ischemia," "reperfusion," "inflow," and "outflow occlusion" was performed.

RESULTS

A multitude of techniques to minimize blood loss during hepatic resection have been studied. The evidence suggests that inflow occlusion techniques are generally well tolerated. These should be used with caution in patients with cirrhosis, fibrosis, steatosis, cholestasis, and recent chemotherapy, and for prolonged time intervals.

CONCLUSIONS

Harmful effects of intraoperative blood loss and transfusion occur during hepatic resection. Portal triad clamping (PTC) is associated with less blood loss compared with no clamping. In procedures with ischemic times <1 hour in length, PTC-C (continuous) is likely equal to PTC-I (intermittent). In patients with chronic liver disease or undergoing lengthy operations, PTC-I is likely superior to PTC-C. PTC is superior to total vascular exclusion except in patients with tumors that are large and deep seated, hypervascular, and/or abutting the hepatic veins or vena cava and in patients with increased right-sided heart pressures.

The 'small for size' liver syndrome

PURPOSE OF REVIEW

Small-for-size syndrome (SFSS) is a clinical syndrome described following liver transplantation (LT) and extended hepatectomy. New evidence has emerged documenting the importance of preoperative evaluation of functional liver mass, liver quality, influence of portal hypertension, and variations in surgical technique to improve outcome.

RECENT FINDINGS

SFSS is characterized by postoperative coagulopathy and liver dysfunction due to insufficient functional liver mass. Recent radiologic advances allow accurate preoperative estimation of total, graft, and remnant liver volume (RLV). In adult-to-adult living donor liver transplantation (LDLT), a graft-to-recipient body weight ratio > or = 0.8% or graft weight ratio > or = 30% are important to avoid SFSS. Minimal functional RLV following extended hepatectomy is > or = 25% in a normal liver, and > or = 40% with preoperative liver dysfunction. Preoperative portal vein or hepatic artery embolization to increase RLV and function after extended hepatectomy, and the increasing use of parenchymal-sparing segmental resections have improved outcome. In LT, the evolving use of split livers, LDLT and marginal grafts has resulted in increased recognition of SFSS. This has led to a renewed interest in defining the pathophysiology, and the development of new surgical techniques to reduce its incidence.

SUMMARY

Current radiologic imaging techniques can be used to evaluate liver volume and the risk of SFSS following LT and extended hepatectomy. Intraoperative techniques to predict postoperative dysfunction are emerging, and may be helpful in directing the use of pre-emptive surgical interventions. The future lies in the development of perioperative liver protection and support in predicted SFSS, and enhancement of healthy liver regeneration.

Significance of the Effective Remnant Liver Volume in Major Hepatectomies

The aim of this study is to identify the minimum safe amount of effective remnant liver volume (ERLV) in patients undergoing a major hepatectomy. Thirty-eight consecutive major hepatectomies (resection of ≥3 Couinaud segments) performed between July 1999 and March 2004 in which a frozen section liver biopsy was obtained were included. No patient had chronic viral hepatitis, cirrhosis, or cholestasis. The total liver volume (TLV) was calculated using the Vauthey formula, and the postsurgical liver volume (PSLV) was derived by subtracting the estimated volume of liver resected from the TLV. The PSLV minus the percentage of macrovesicular steatosis as nonfunctional liver was defined as the effective remnant liver volume (ERLV). Three groups of ERLV/TLV ratios (<30%, between 30% and 60%, and >60%) were correlated with liver resection type, mortality, complications, intraoperative blood transfusions, operative time, length of hospitalization, and mean value of liver function tests in the first 5 postoperative days. Comparisons between clinical parameters were performed by Pearson χ2 test. There was significant correlation between ERLV/TLV ratios and surgical resection type ( P < 0.001), early postoperative mortality ( P < 0.01), and complications ( P < 0.003). The ERLV/TLV ratio may be a useful predictor of surgical outcome after major hepatectomy.

General management

Hepatocellular carcinoma is one of the most common malignancies worldwide. The general management of hepatocellular carcinoma begins with an accurate diagnosis. With advances in imaging studies, noninvasive diagnosis has become an accepted standard of care for hepatocellular carcinoma, though pathologic examination is still required in selected cases. Following diagnosis, accurate staging is the next most important step in selecting the most appropriate treatment modality. Patients with localised tumor and compensated liver disease should be considered for partial hepatectomy, and patients with poor hepatic function but early tumor stage are candidates for liver transplantation. Patients who do not qualify for either of these curative treatments may be evaluated for palliative therapy, of which transarterial chemoembolisation is most widely used. This review will discuss the role of biopsy, the pros and cons of noninvasive and pathologic tissue diagnosis as well as the general approach to choose the most appropriate treatment for patients with hepatocellular carcinoma.

In-contiguity and non-anatomical extension of right hepatic trisectionectomy for liver metastases

Background

In some patients undergoing right hepatic trisectionectomy for metastases, extension of the resection beyond the falciform ligament is necessary to achieve tumour clearance. The aim of the present study was to assess the early and long-term outcomes and hepatic function in patients who underwent extensive liver resection beyond right trisectionectomy.

Methods

Thirty-eight patients who had extension of a right trisectionectomy, either in contiguity (IC) or in a non-anatomical (NA) fashion, for liver metastases were included in the study. In-hospital mortality, hepatic function and other morbidity were recorded. Survival outcomes were analysed for the subgroup of patients with colorectal liver metastases. The clinical risk score described by the Memorial Sloan–Kettering Cancer Center was applied to all patients with colorectal liver metastases.

Results

Sixteen patients had IC resection, 15 NA resection, and seven had both IC and NA procedures. There was one in-hospital death. Hepatic dysfunction was seen in 25 patients and two developed liver failure. Disease-free actuarial 3-year survival was 42 per cent for patients with colorectal liver metastases. Survival was significantly better in patients with a clinical risk score of 3 or less.

Conclusion

Extension of right trisectionectomy for liver metastases was associated with a low risk of death and hepatic failure.

Operative considerations in resection of hilar cholangiocarcinoma

This article reviews the preoperative evaluation and operative considerations in patients with hilar cholangiocarcinoma. The preoperative evaluation is based on the imaging evaluation of the longitudinal and radial extent of the tumour along and around the hepatic duct confluence. The use of portal vein embolization to increase the safety of extended hepatectomy and the extent of surgical resection (caudate lobe and portal vein) are discussed within the context of recently published series.

Surgical treatment of hepatocellular carcinoma

Surgery for hepatocellular carcinoma (HCC) includes partial liver resection (LR) and liver transplantation (LT). Although LT represents the most efficient treatment in patients with small HCC, <30% of patients are eligible for LT because of restrictive criteria (one nodule <5 cm or two to three nodules <3 cm without macroscopic vascular invasion), graft unavailability and the high cost of the procedure. For large HCC, LR remains the only potential curative treatment. LR is now safer, with a low rate of mortality. Selective preoperative morphological assessment, preoperative use of portal vein embolization for increasing future remnant liver volume and the improvement of surgical techniques such as the use of intermittent clamping and anterior approach are factors that improve the safety and tolerance of LR. In patients with small HCCs and a preserved liver function (Child-Pugh grade A), good long-term survival can be achieved after anatomical resection that removes the tumor(s) and its portal vein territory. These good results of LR for small HCC and the increasing duration of the waiting list for candidates of LT have renewed the place of LR as a bridge treatment before LT.

Hemodynamic and morphologic changes after portal vein embolization: differential effects in central and peripheral zones in the liver on multiphasic computed tomography

OBJECTIVE

To evaluate hemodynamic and morphologic effects in the liver after portal vein embolization (PVE).

METHODS

Hepatic computed tomography scans of 7 patients who had undergone preoperative PVE were retrospectively reviewed. Pre- and post-PVE computed tomography densities were evaluated for the unenhanced, late arterial, and portal venous phases in peripheral and central hepatic regions and in the 3 main hepatic veins. Relative changes in areas in these regions were assessed in 5 evaluable patients with serial post-PVE scans.

RESULTS

During the late arterial phase, enhancement was significantly higher after PVE than it was before PVE in the peripheral hepatic regions, and it was higher in the peripheral regions than in the central regions. Enhancement was also significantly higher in the right main hepatic vein than in the middle and left hepatic veins during the late arterial phase. The ratio of areas of the peripheral/central regions decreased significantly after PVE.

CONCLUSIONS

Zonal enhancement in the late arterial phase changed after PVE and seemed to be associated with differential parenchymal atrophy. We speculate that the hepatic arterial supply increases peripherally and that peribiliary/periportal plexuses maintain the portal supply centrally.

Transcatheter selective portal vein embolization in treatment of hepatocellular carcinoma: an analysis of 20 cases

AIM: To evaluate the clinical value of transcatheter selective portal vein embolization (PVE) in treatment of hepatocellular carcinoma.

METHODS: Twenty patients, with unresectable advanced hepatocellular carcinoma, were treated with right PVE under fluoroscopic guidance. Left hepatic lobe volume was obtained by computerized tomography (CT) before and after PVE. Portal venous pressure, hepatic and thromboplastic functions were also detected before and after PVE.

RESULTS: Right portal vein were embolized successfully in 20 patients. Compensatory hypertrophy was observed in left hepatic lobe. The volume of left hepatic lobe increased significantly with a total percentage of 25% in 13 patients (65%) at 4 wk after PVE (P <0.01). Right hepatic lobe was successfully resected in 1 patient. No patients had complications such as portal hypertension after PVE. Slight damage of liver function after PVE was observed.

CONCLUSION: PVE can induce compensatory hypertrophy of liver lobes, which provides another operation chance for patients with unresectable hepatocellular carcinoma.

Safety of hepatectomy for living donors as evaluated using asialoscintigraphy

In the living donor operation, accurate estimation of hepatic functional reserve is essential. Technetium-99m-galactosyl-human serum albumin (GSA) is a liver scintigraphy agent that binds to asialoglycoprotein receptors. We evaluated the preoperative assessment of the safety of an elective hepatectomy using GSA liver scintigraphy in 152 patients. GSA scintigraphy was performed after intravenous injection of GSA. The maximal removal rate of GSA (GSA-Rmax) was calculated using a radiopharmacokinetic model. We determined the areas for resection preoperatively depending on the operative procedures and calculated the local GSA-Rmax in the predicted residual liver (GSA-RL). A significant correlation was obtained between the GSA-Rmax and the 15-minute retention rate of indocyanine green. With sub- and monosegmentectomy, 2 patients had postoperative hepatic failure; in those 2 patients, the GSA-RL was 0.127 and 0.133, respectively, but these patients recovered well. Among those having di- and tri-segmentectomy, 5 patients experienced postoperative hepatic failure, in all subjects the GSA-RL was <0.15. Two patients died of postoperative liver failure 1 to 2 months after the operation. We concluded that GSA-RL is useful to select the procedure for hepatectomy in living donors and that GSA-RL should be >0.15 (mg/min/50 kg body weight) to avoid postoperative hepatic failure.

Advances in the surgical management of liver malignancies

Primary malignancies of the liver include tumors arising from the hepatocytes (hepatocellular carcinoma and the fibrolamellar variant) and the intrahepatic bile ducts (intrahepatic cholangiocarcinoma). Hepatocellular carcinoma is the most common primary cancer of the liver and is a leading cause of death from cancer worldwide. Although it is uncommon in the United States, the incidence of hepatocellular carcinoma is rising. Hepatitis, ethanol use, and cirrhosis often dominate the clinical picture and may dictate prognosis. New clinical and pathological staging systems have allowed for the more accurate stratification of patients to more appropriately identify patients for resection, transplantation, and percutaneous ablation therapies. A correlation between liver volume and surgical outcome has recently been demonstrated, with small liver remnant size being associated with increased morbidity. Portal vein embolization has therefore been proposed as one way to induce hypertrophy of the anticipated liver remnant before resection. Initial reports have shown that portal vein embolization decreases the incidence of postoperative complications. More recently, systemic chemotherapy and chemoembolization have been investigated as both primary and neoadjuvant therapy. Chemoimmunotherapy with 5-fluorouracil and interferon may be associated with a superior response rate in the fibrolamellar variant of hepatocellular carcinoma. Two recent randomized studies have also indicated improved survival after hepatic artery embolization in selected patients.

Contralateral Portal Vein Embolization for Hepatectomy in the Setting of Hepatic Steatosis

Portal vein embolization is evolving as an important adjunctive tool in hepatic surgery. In select patients, preoperative hypertrophy of the future remnant liver via contralateral portal vein embolization decreases postoperative liver dysfunction. Hepatic steatosis is the most common liver parenchymal disorder in Western populations. Moderate and severe degrees of hepatic steatosis convey an increased risk of postoperative liver dysfunction following major hepatic resections, but no studies exist examining the role of preoperative portal vein embolization in patients with hepatic steatosis. In this manuscript, we review the indications for portal vein embolization currently supported by the literature and present a patient with moderate to severe steatosis who successfully underwent portal vein embolization and a subsequent major liver resection.

[Evaluation of living donors for liver transplantation: radiology and virtual surgery]

PURPOSE

To propose a comprehensive imaging algorithm of living donors for liver transplantation allowing virtual presurgical planning.

MATERIAL AND METHODS

Prospective CT and MRI evaluation of 20 patients selected as potential living donors for liver transplantation, between June 2001 and March 2003. For each patient, a virtual hepatectomy according to anatomical biliary and vascular variations, total liver Volume and residual liver Volume, were simulated. The imaging results were correlated to the surgical findings.

RESULTS

CT and MRI demonstrated thirty-five vascular and biliary anatomical variations in 17 patients. Knowledge of these variations resulted in modification of the surgical planning in 6 cases. Four additional variations were described at surgery. The virtual graft Volumes correlated well to the surgical ones (p<0.0001).

CONCLUSIONS

CT and MRI are useful for the presurgical evaluation of living donors prior to liver transplantation. Estimation of the residual liver Volume allows a good prediction of the postsurgical outcome.

Hepatic colorectal metastases: methods of improving resectability

Surgery is the best treatment modality for colorectal liver metastases. When initially unresectable, hepatic resection of metastases after downstaging by chemotherapy can provide a hope of long-term survival similar to that of primarily resected patients. Definitions of resectability have evolved with the emerging principle that if metastases can be completely resected regardless of their size and number,resection should be performed as the sole mean of achieving long-term survival. Specific surgical techniques can be combined to improve resectability. If the tumor is considered unresectable, recent developments make possible to render some tumors surgically resectable. Depending on the tumor size, number and location, neoadjuvant treatments, mainly chemotherapy, can be used, followed by resection. Resection may be contraindicated if the residual volume of liver is inadequate to avoid liver failure. This may be changed either by PVE or two-stage hepatectomy, both of which use the natural regenerative capacity of the liver. Local destructive therapies such as cryosurgery and radio-frequency can also be used in conjunction with resection for patients in whom all metastases are not surgically resectable. The present use of these ablative techniques is improving the percentages of unresectable patients considered for surgery. All of the above-described methods can be combined to achieve a surgical strategy that is as curative as possible, increasing the number of patients primarily unresectable, with a long-term survival hope similar to that of primarily resectable patients. To achieve this objective, a close collaboration between oncologists, radiologists, and surgeons is mandatory, with routine re-evaluation of patients for an adequate timing of each treatment.

Is extended hepatectomy for hepatobiliary malignancy justified?

BACKGROUND

Extended hepatectomy may be required to provide the best chance for cure of hepatobiliary malignancies. However, the procedure may be associated with significant morbidity and mortality.

METHODS

We analyzed the outcome of 127 consecutive patients who underwent extended hepatectomy (resection of > or = 5 liver segments) for hepatobiliary malignancies.

RESULTS

The patients underwent extended hepatectomy for colorectal metastases (n = 86; 67.7%), hepatocellular carcinoma (n =12; 9.4%), cholangiocarcinoma (n =14; 11.0%), and other malignant diseases (n =15; 11.5%). Thirty-two left and ninety-five right extended hepatectomies were performed. Eight patients also underwent caudate lobe resection, and 40 patients underwent a synchronous intraabdominal procedure. Twenty patients underwent radiofrequency ablation, and 31 underwent preoperative portal vein embolization. The median blood loss was 300 mL for right hepatectomy and 600 mL for left hepatectomy (P = 0.02). Thirty-six patients (28.3%) received a blood transfusion. The overall complication rate was 30.7% (n = 39), and the operative mortality rate was 0.8% (n = 1). Significant liver insufficiency (total bilirubin level > 10 mg/dL or international normalized ratio > 2) occurred in 6 patients (4.7%). Multivariate analysis showed that a synchronous intraabdominal procedure was the only factor associated with an increased risk of morbidity (hazard ratio [HR], 4.9; P = 0.02). The median survival was 41.9 months. The overall 5-year survival rate was 25.5%.

CONCLUSIONS

Extended hepatectomy can be performed with a near-zero operative mortality rate and is associated with long-term survival in a subset of patients with malignant hepatobiliary disease. Combining extended hepatectomy with another intraabdominal procedure increases the risk of postoperative morbidity.

Total and segmental liver volume variations: Implications for liver surgery

BACKGROUND

Liver remnant volumes after major hepatic resection and graft volumes for liver transplantation correlate with surgical outcome. The relative contributions of the hepatic segments to total liver volume (TLV) are not well established.

METHODS

TLV and hepatic segment volumes were measured with computed tomography (CT) in 102 patients without liver disease who underwent CT for conditions unrelated to the liver or biliary tree.

RESULTS

TLV ranged from 911 to 2729 cm(3). On average, the right liver (segments V, VI, VII, and VIII) contributed approximately two thirds of TLV (997+/-279 cm(3)), and the left liver (segments II, III and IV) contributed approximately one third of TLV (493+/-127 cm(3)). Bisegment II+III (left lateral section) contributed about half the volume of the left liver (242+/-79 cm(3)), or 16% of TLV. Liver volumes varied significantly between patients--the right liver varied from 49% to 82% of TLV, the left liver, 17% to 49% of TLV, and bisegment II+III (left lateral section) 5% to 27% of TLV. Bisegment II+III contributed less than 20% of TLV in more than 75% of patients and the left liver contributed 25% or less of TLV in more than 10% of patients.

DISCUSSION

There is clinically significant interpatient variation in hepatic volumes. Therefore, in the absence of appreciable hypertrophy, we recommend routine measurement of the future liver remnant before extended right hepatectomy (right trisectionectomy) and in selected patients before right hepatectomy if a small left liver is anticipated.

Evaluation of liver function for hepatic resection for hepatocellular carcinoma in the liver with damaged parenchyma

BACKGROUND

Liver functional parameters, including the Child-Pugh score and indocyanine green clearance (ICG), and volumetric parameters influencing postoperative liver function were evaluated with the aim of obtaining standardardized criteria for selecting patients for, and deciding the extent of, hepatectomy for hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

The study population consisted of 120 patients with HCC undergoing hepatic resection excluding those with more than 3000 ml of intraoperative bleeding. Patients were classified as grades A, B, or C on the basis of, respectively, a Child-Pugh score of 5 or 6, 7-9, or >or=10 and were assigned to group D (postoperative liver dysfunction) or group N (no complication). Postoperative complications included massive ascites, pleural effusion, or hyperbilirubinemia. For each grade, the standardized estimated liver remnant ratio (STELR) was determined as the ratio of the liver remnant volume (estimated by computerized tomography) to the standardized total liver volume (STLV), estimated from the body surface area using the equation: liver volume [cm(3)] = 706 x body surface area [m(2)] + 2.4. The ICG retention rate at 15 min after injection (ICGR15) was then plotted against the STELR for each grade and a demarcation line separating patients in groups N and D was determined statistically by discriminant analysis.

RESULTS

For grade A patients, the equation of the demarcation line was ICGR15 = 27.5 x STELR + 1.9 (Wilks' Lambda: 0.667, P < 0.001), indicating that, for safe hepatic resection in patients with an ICGR15 of 10%, the STELR should be greater than 0.29. In contrast, for grade B patients, the equation was ICGR15 = 72 x STELR - 22.1 (0.589, P < 0.001), indicating that, in patients with a 10% ICGR15, the STELR should be greater than 0.44, a larger value than in grade A patients. The number of grade C patients was too small for analysis.

CONCLUSIONS

By combining the Child-Pugh score, ICG clearance, and liver volumetric parameters, criteria for the selection of patients for hepatic resection for HCC were established.

Hepatectomy for hepatocellular carcinoma: patient selection and postoperative outcome

Hepatic resection and liver transplantation are considered the only curative treatments for hepatocellular carcinoma (HCC). Liver transplantation for HCCs < or =5 cm in diameter has been shown to produce favorable survival results, but its application is limited by the lack of donors. Hepatic resection remains the treatment of choice for patients who are not transplantation candidates because of large tumor, macroscopic vascular invasion, or advanced age. For small HCCs associated with Child's A cirrhosis, hepatic resection should still be considered the first-line treatment, but salvage transplantation for intrahepatic recurrence may be a feasible strategy. Recent improvement in surgical techniques and perioperative care has increased the safety and expanded the indication of hepatic resection for HCC to include large tumors that require extended hepatectomy in cirrhotic patients. Selection of appropriate candidates for hepatectomy depends on careful assessment of the tumor status and liver function reserve. Evaluation of the general fitness of patients is also critical because comorbid illness is an important cause of postoperative mortality, even if the patients have good liver function reserve. With careful patient selection and surgical expertise, the current operative mortality of hepatectomy for HCC is about 5% or less in major centers. Improved long-term survival results after resection of HCC have also been reported recently, with an overall 5-year survival rate of about 50%. The improved perioperative and long-term survival results have strengthened the role of hepatectomy as the mainstay of treatment for HCC despite the availability of a number of other treatment options for localized HCC.

Strategies to increase the resectability of liver metastases from colorectal cancer

Liver resection can provide long-term survival and cure for patients with colorectal liver metastases but is feasible in only 15-25% of patients. In the last few years several major developments have contributed to increase this resectability rate. Neo-adjuvant chemotherapy can provide response rates as high as 50%, allowing surgery in about 10-15% of patients initially deemed unresectable. Patients requiring extensive liver resections with an anticipated small residual liver volume can undergo portal vein embolization to reduce the risk of postoperative liver failure by inducing hypertrophy of the remnant liver. Extensive bilobar disease can be treated by two-stage hepatectomy, with an interval to allow liver regeneration. Ablation techniques can be combined with hepatic resection to reduce local recurrence from incomplete surgical resection margins or to destroy contralateral tumor deposits. Finally, for patients with tumors involving the inferior vena cava or the hepatic veins, in which conventional resection is not feasible, in situ hypothermia or bench resection with reimplantation are suitable for very selected patients. Downstaging strategies may increase the resectability rate of colorectal liver metastases by over 20%.

The small remnant liver after major liver resection: how common and how relevant?

The maximum extent of hepatic resection compatible with a safe postoperative outcome is unknown. The study goal was to determine the incidence and impact of a small remnant liver volume after major liver resection in patients with normal liver parenchyma. Among 265 major hepatectomies performed at our institution (1998 to 2000), 138 patients with normal liver and a remnant liver volume (RLV) systematically calculated from the ratio of RLV to functional liver volume (FLV) were studied. Patients were divided into five groups based on RLV-FLV ratio from </=30% to >/=60%. Kinetics of postoperative liver function tests were correlated with RLV. Postoperative complications were stratified by RLV-FLV ratios. Ninety patients (65%) underwent resection of up to four Couinaud segments. The RLV-FLV ratio was </=60% in 94 patients (68%) including only 13 (9%) with RLV-FLV </=30%. There was no linear correlation between the number of resected segments and the RLV-FLV. Postoperative serum bilirubin but not prothrombin time correlated with extent of resection. The incidence of complications including liver failure was not different among groups. Analysis of the four groups with a RLV-FLV ratio <60% showed a trend toward more complications and a longer intensive care unit stay in patients with the smallest RLVs. After major hepatectomy in patients with normal livers, the proportion of patients with a small remnant liver is low and not directly related to the number of segments resected. Although the rate of postoperative complications, including liver failure, did not directly correlate with the volume of remaining liver, the postoperative course was more difficult for patients with smaller remnants. Therefore preoperative portal vein embolization should be considered in patients who will undergo extended liver resection who have (1) injured liver or (2) normal liver when the planned procedure will be complex or when the anticipated RLV-FLV will be <30%.

Preoperative portal vein embolization for extended hepatectomy

OBJECTIVE

To examine the authors' experience with preoperative ipsilateral portal vein embolization (PVE) and assess its role in extended hepatectomy.

SUMMARY BACKGROUND DATA

Extended hepatectomy (five or more liver segments) has been associated with higher complication rates and increased postoperative liver dysfunction than have standard hepatic resections involving lesser volumes. Recently, PVE has been used in patients who have a predicted (postresection) future liver remnant (FLR) volume less than 25% of total liver volume in an attempt to increase the FLR and reduce complications.

METHODS

Sixty patients from 1996 to 2002 were reviewed. Thirty-nine patients had PVE preoperatively. Eight patients who had PVE were not resected either due to the discovery of additional unresectable disease after embolization but before surgery (n = 5) or due to unresectable disease at surgery (n = 3). Therefore, 31 patients who had PVE subsequently underwent extended hepatic lobectomy. A comparable cohort of 21 patients who had an extended hepatectomy without PVE were selected on the basis of demographic, tumor, and liver volume characteristics. Patients had colorectal liver metastases (n = 30), hepatocellular carcinoma (n = 15), Klatskin tumors (n = 9), peripheral cholangiocarcinoma (n = 3), and other tumors (n = 3). The 52 resections performed included 42 extended right hepatectomies, 6 extended left hepatectomies, and 4 right hepatectomies extended to include the middle hepatic vein and the caudate lobe but preserving the majority of segment 4. Concomitant vascular reconstruction of either the inferior vena cava or hepatic veins was performed in five patients.

RESULTS

There were no differences between PVE and non-PVE groups in terms of tumor number, tumor size, tumor type, surgical margin status, complexity of operation, or perioperative red cell transfusion requirements. The predicted FLR was similar between PVE and non-PVE groups at presentation. After PVE the FLR was higher than in the non-PVE group. No complications were observed after PVE before resection. There was no difference in postoperative mortality, with one death from liver failure in the non-PVE group and no operative mortality in the PVE group. Postoperative peak bilirubin was higher in the non-PVE than the PVE group, as were postoperative fresh-frozen plasma requirements. Liver failure (defined as the development of encephalopathy, ascites requiring sustained diuretics or paracentesis, or coagulopathy unresponsive to vitamin K requiring fresh-frozen plasma after the first 24 hours postresection) was higher in the non-PVE patients than the PVE patients. The hospital stay was longer in the non-PVE than the PVE group.

CONCLUSIONS

Preoperative PVE is a safe and effective method of increasing the remnant liver volume before extended hepatectomy. Increasing the remnant liver volume in patients with estimated postresection volumes of less than 25% appears to reduce postoperative liver dysfunction.

A simple new formula to assess liver weight

INTRODUCTION

In cadaveric or segmental liver transplantation, accurate assessment of graft volume is desirable but not always easy to achieve based on donor morphometric data. We sought to establish a simple, reliable formula for accurate prediction of liver volume.

METHODS

Data from 1,413 cadaveric adult and pediatric liver donors were analyzed using simple and multiple regression analysis. Liver weight (LW) was plotted against age, height, body weight (BW), body surface area (BSA) or body mass index (BMI); a formula was developed using simple regression: LW (g) = 772 (g/m(2)) x BSA, r = 0.73, P <.01. For donors with BSA </=1.0, a pediatric factor (PF) of 1.0 was included, resulting in the formula: LW (g) = 772 (g/m(2)) x BSA - 38PF, r = 0.73, P <.01. We then applied our formula on 5 published formulae to estimate LW of our donors.

RESULTS

Among donors with BSA >1.0, there was no significant difference between the actual and the estimated mean LW as calculated by the new formula. For pediatric donors, there was no significant difference between estimated and actual mean liver weight with any formula. When the new formula was applied, the difference between the actual and the estimated liver weight was acceptable (<20%) in 1040 (73.6%) cases. In all races, there was no significant difference between actual and estimated mean liver weight as calculated by this formula.

CONCLUSIONS

A simple formula to calculate liver weight in donors with BSA >1.0 is: LW = 772 x BSA, and for donors with BSA </=1.0: Liver Weight = 772 x BSA - 38.

Preoperative portal vein embolization for extended hepatectomy

OBJECTIVE

To examine the authors' experience with preoperative ipsilateral portal vein embolization (PVE) and assess its role in extended hepatectomy.

SUMMARY BACKGROUND DATA

Extended hepatectomy (five or more liver segments) has been associated with higher complication rates and increased postoperative liver dysfunction than have standard hepatic resections involving lesser volumes. Recently, PVE has been used in patients who have a predicted (postresection) future liver remnant (FLR) volume less than 25% of total liver volume in an attempt to increase the FLR and reduce complications.

METHODS

Sixty patients from 1996 to 2002 were reviewed. Thirty-nine patients had PVE preoperatively. Eight patients who had PVE were not resected either due to the discovery of additional unresectable disease after embolization but before surgery (n = 5) or due to unresectable disease at surgery (n = 3). Therefore, 31 patients who had PVE subsequently underwent extended hepatic lobectomy. A comparable cohort of 21 patients who had an extended hepatectomy without PVE were selected on the basis of demographic, tumor, and liver volume characteristics. Patients had colorectal liver metastases (n = 30), hepatocellular carcinoma (n = 15), Klatskin tumors (n = 9), peripheral cholangiocarcinoma (n = 3), and other tumors (n = 3). The 52 resections performed included 42 extended right hepatectomies, 6 extended left hepatectomies, and 4 right hepatectomies extended to include the middle hepatic vein and the caudate lobe but preserving the majority of segment 4. Concomitant vascular reconstruction of either the inferior vena cava or hepatic veins was performed in five patients.

RESULTS

There were no differences between PVE and non-PVE groups in terms of tumor number, tumor size, tumor type, surgical margin status, complexity of operation, or perioperative red cell transfusion requirements. The predicted FLR was similar between PVE and non-PVE groups at presentation. After PVE the FLR was higher than in the non-PVE group. No complications were observed after PVE before resection. There was no difference in postoperative mortality, with one death from liver failure in the non-PVE group and no operative mortality in the PVE group. Postoperative peak bilirubin was higher in the non-PVE than the PVE group, as were postoperative fresh-frozen plasma requirements. Liver failure (defined as the development of encephalopathy, ascites requiring sustained diuretics or paracentesis, or coagulopathy unresponsive to vitamin K requiring fresh-frozen plasma after the first 24 hours postresection) was higher in the non-PVE patients than the PVE patients. The hospital stay was longer in the non-PVE than the PVE group.

CONCLUSIONS

Preoperative PVE is a safe and effective method of increasing the remnant liver volume before extended hepatectomy. Increasing the remnant liver volume in patients with estimated postresection volumes of less than 25% appears to reduce postoperative liver dysfunction.

Portal vein embolization with polyvinyl alcohol particles and coils in preparation for major liver resection for hepatobiliary malignancy: safety and effectiveness--study in 26 patients

PURPOSE

To evaluate whether preoperative portal vein embolization (PVE) with polyvinyl alcohol (PVA) particles and coils is safe and effective for inducing lobar hypertrophy in patients with hepatobiliary malignancy.

MATERIALS AND METHODS

PVE was performed in 26 patients. All patients had malignancy: metastases (n = 11), cholangiocarcinoma (n = 9), hepatocellular carcinoma (n = 5), and gallbladder carcinoma (n = 1). One patient had underlying liver disease caused by hepatitis. PVE was performed if the future liver remnant (FLR) was estimated to be less than 25% of the total liver volume. PVE was performed with a percutaneous transhepatic approach (right, 25 patients; left, one patient). PVA particles and coils were used to occlude the right portal system and veins supplying segment IV to promote FLR hypertrophy (segments I-III +/- IV). FLR hypertrophy was assessed with comparison of computed tomographic scans obtained before and 2-4 weeks after PVE. Effectiveness evaluation was based on changes in absolute FLR size and ratio of FLR to total estimated liver volume (TELV). Safety of PVE and hepatic resection was determined with postprocedure complication rate and median hospital stay.

RESULTS

Sixteen patients underwent hepatic resection (right trisegmentectomy [n = 13], right lobectomy [n = 3]) without mortality. Ten patients did not undergo resection (complete remission after medical therapy [n = 1], lack of regeneration [n = 2], extrahepatic disease undetected prior to PVE [n = 7]). Six patients had biliary obstruction; five were treated percutaneously before PVE. No patient developed postembolization syndrome or signs of fulminant hepatic insufficiency after PVE or resection. Two patients had complications after PVE that did not preclude successful resection. Median hospital stays were 1 day (PVE) and 7 days (liver resection). Mean absolute FLR increased from 325.0 to 458.6 cm3 (increase, 41.1%). Mean TELV was 1,784.8 cm3. FLR/TELV ratio increase was 8%.

CONCLUSION

Preoperative PVE with PVA particles and coils is safe and effective for inducing lobar hypertrophy in patients with advanced hepatobiliary malignancy.