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

Pretreatment assessment of hepatocellular carcinoma: expert consensus statement

Staging of hepatocellular carcinoma (HCC) is complex and relies on multiple factors including tumor extent and hepatic function. No single staging system is applicable to all patients with HCC. The staging of the American Joint Committee on Cancer / International Union for Cancer Control should be used to predict outcome following resection or liver transplantation. The Barcelona Clinic Liver Cancer scheme is appropriate in patients with advanced HCC not candidate for surgery. Dual phase computed tomography or magnetic resonance imaging can be used for pretreatment assessment of tumor extent but the accuracy of these methods remains poor to characterize < 1 cm lesions. Assessment of tumor response should not rely only on tumor size and new imaging methods are available to evaluate response to therapy in HCC patients. Liver volumetry is part of the preoperative assessment of patients with HCC candidate for resection as it reflects liver function. Preoperative portal vein embolization is indicated in patients with small future liver remnant (≤ 20% in normal liver; ≤ 40% in fibrotic or cirrhotic liver). Tumor size is not a contraindication to liver resection. Liver resection can be proposed in selected patients with multifocal HCC. Besides tumor extent, surgical resection of HCC may be performed in selected patients with chronic liver disease.

Concurrent and subsequent radiofrequency ablation combined with hepatectomy for hepatocellular carcinomas

Partial hepatectomy has long been the standard treatment modality for patients with hepatocellular carcinoma (HCC), although the majority of patients with HCCs are not candidates for curative resection. Radiofrequency ablation (RFA) has been widely used as the preferred locoregional therapy. RFA and hepatectomy can be complementary to each other for the treatment of multifocal HCCs. Combining hepatectomy with RFA permits the removal of larger tumors while simultaneously ablating any smaller residual tumors. By using this combination treatment, more patients might become candidates for curative resection. For treating recurrent tumors involving the liver after hepatectomy, RFA has been performed recently instead of transcatheter arterial chemoembolization or ethanol ablation. Many retrospective studies on the combination of RFA and hepatectomy demonstrate favorable results of effectiveness and safety. However, further investigation of prospective design will be needed to confirm these encouraging results.

Nuclear imaging techniques for the assessment of hepatic function in liver surgery and transplantation

This review describes the application of 2 nuclear imaging techniques for assessment of hepatic function in the setting of liver surgery and transplantation. The biochemical and technical background, as well as the clinical applications, of (99m)Tc-labeled diethylenetriaminepentaacetic acid galactosyl human serum albumin (GSA) scintigraphy and hepatobiliary scintigraphy (HBS) with (99m)Tc-labeled iminodiacetic acid derivates is discussed. (99m)Tc-mebrofenin is considered the most suitable iminodiacetic acid agent for (99m)Tc-HBS. (99m)Tc-GSA scintigraphy and (99m)Tc-mebrofenin HBS are based on 2 different principles. (99m)Tc-GSA scintigraphy is a receptor-mediated technique whereas HBS represents hepatic uptake and excretion function. Both techniques are noninvasive and provide visual and quantitative information on both total and regional liver function. They can be used for preoperative assessment of future remnant liver function, follow-up after preoperative portal vein embolization, and evaluation of postoperative liver regeneration. In liver transplantation, these methods are used to assess graft function and biliary complications.

(99m)Tc-mebrofenin hepatobiliary scintigraphy with SPECT for the assessment of hepatic function and liver functional volume before partial hepatectomy

Preoperative evaluation of future remnant liver (FRL) function is crucial in the determination of whether a patient can safely undergo liver resection. Although dynamic (99m)Tc-mebrofenin hepatobiliary scintigraphy (HBS) is used to measure FRL function, 2-dimensional planar images lack the ability to assess segmental liver function. Modern SPECT/CT cameras combine dynamic (99m)Tc-mebrofenin HBS with additional SPECT and the anatomic information of the CT scan. The aim of this study was to evaluate the additional value of (99m)Tc-mebrofenin SPECT for the measurement of segmental liver function and liver functional volume.

METHODS

Preoperative CT volumetry and (99m)Tc-mebrofenin HBS with SPECT were performed in 36 patients undergoing liver resection. In 18 patients, postoperative (99m)Tc-mebrofenin HBS with SPECT was performed within 3 d after operation. Dual-head dynamic acquisitions were used to calculate FRL function using anterior and geometric mean (Gmean) datasets. Total and FRL functional liver volumes were measured by SPECT.

RESULTS

Because of the anatomic position of the liver, the anterior projection resulted in an underestimation of FRL function in patients undergoing left hemihepatectomy. In patients with normal liver parenchyma, total functional liver volume was comparable to total liver volume measured by CT volumetry, indicating that (99m)Tc-mebrofenin SPECT is an accurate method to measure hepatic volume. In compromised livers, compared with normal livers, FRL function per cubic centimeter of liver volume was significantly less. In addition, liver function was not distributed homogeneously, with the segments to be resected relatively more affected. FRL function, measured by a combination of SPECT and dynamic HBS, was able to accurately predict actual postoperative remnant liver function.

CONCLUSION

The Gmean dataset is recommended for the assessment of hepatic function by dynamic planar (99m)Tc-mebrofenin HBS. The combination of SPECT data with the dynamic uptake function measured by planar HBS provides valuable visible and quantitative information regarding segmental liver function and is an accurate measure for FRL function.

Assessment of future remnant liver function using hepatobiliary scintigraphy in patients undergoing major liver resection

BACKGROUND

(99m)Tc-mebrofenin hepatobiliary scintigraphy (HBS) was used as a quantitative method to evaluate liver function. The aim of this study was to compare future remnant liver function assessed by (99m)Tc-mebrofenin hepatobiliary scintigraphy with future remnant liver volume in the prediction of liver failure after major liver resection.

METHODS

Computed tomography (CT) volumetry and (99m)Tc-mebrofenin hepatobiliary scintigraphy were performed prior to major resection in 55 high-risk patients, including 30 patients with parenchymal liver disease. Liver volume was expressed as percentage of total liver volume or as standardized future remnant liver volume. Receiver operating characteristic (ROC) curve analysis was performed to identify a cutoff value for future remnant liver function in predicting postoperative liver failure.

RESULTS

Postoperative liver failure occurred in nine patients. A liver function cutoff value of 2.69%/min/m(2) was calculated by ROC curve analysis. (99m)Tc-mebrofenin hepatobiliary scintigraphy demonstrated better sensitivity, specificity, and positive and negative predictive value compared to future remnant liver volume. Using 99mTc-mebrofenin hepatobiliary scintigraphy, one cutoff value suffices in both compromised and noncompromised patients.

CONCLUSION

Preoperative (99m)Tc-mebrofenin hepatobiliary scintigraphy is a valuable technique to estimate the risk of postoperative liver failure. Especially in patients with uncertain quality of the liver parenchyma, (99m)Tc-mebrofenin HBS proved of more value than CT volumetry.

Predicting liver failure following major hepatectomy

Pre-operative determination of the risk of liver dysfunction has come under criticism with regards to its usefulness in clinical practice. Opinion is split between centres which use such tests uniformly on all patients and those where clinical judgment alone is used. Published data would not suggest any difference in mortality, morbidity or liver failure rates between these groups. This review outlines and presents the evidence for pre-operative quantification of functional liver remnant volume.

Three hundred and one consecutive extended right hepatectomies: evaluation of outcome based on systematic liver volumetry

OBJECTIVE(S)

This study aimed to determine the effect of preoperative liver volumetry on postoperative outcomes after extended right hepatectomy. Primary end point was to evaluate whether future liver remnant (FLR)/standardized liver volume ratio (sFLR) >20% is sufficient for a safe hepatic resection. Secondary end point was to assess whether preoperative portal vein embolization (PVE) is associated with improved outcome in patients with initial sFLR ≤ 20%.

BACKGROUND DATA

An sFLR >20% of the total liver volume has been proposed as sufficient for safe hepatic resection, but this concept has not been validated in a large series. In addition, recent reports suggest preoperative PVE is indicated for sFLR <30%.

METHODS

The impact of sFLR and PVE on short-term outcomes (postoperative complications, liver insufficiency, and 90-day mortality) was analyzed in 301 consecutive patients after extended right hepatectomy. Liver volumetry accounted for partial resection of segment IV. Liver insufficiency was defined as peak postoperative serum bilirubin >7 mg/dL. Predictors of liver insufficiency were identified by multivariate logistic regression.

RESULTS

Postoperative liver insufficiency occurred in 45 patients (15%) and accounted for 61% of deaths. Among 290 patients who underwent liver volumetry, sFLR was <20% in 38 patients, 20.1% to 30% in 144, and ≥ 30% in 108. Rates of postoperative liver insufficiency and death from liver failure were similar between patients with sFLR 20.1% to 30% and sFLR ≥ 30% but higher in patients with sFLR ≤ 20% (P 0.05). Postoperative outcomes were similar between patients with increase in sFLR from ≤ 20% to >20% after PVE and patients with initial sFLR >20%. Multivariate analysis revealed that body mass index >25 kg/m2, intraoperative blood transfusion, and sFLR ≤ 20% (odds ratio = 3.18; 95% CI, 1.34-7.54) independently predicted postoperative liver insufficiency.

CONCLUSIONS

Systematic measurement of FLR volume is important to select patients for PVE and extended right hepatectomy. A sFLR >20% is sufficient for safe hepatic resection and sFLR 20.1% to 30% is not an indication for preoperative PVE.

Update and review of the multidisciplinary management of stage IV colorectal cancer with liver metastases

Background

The management of stage IV colorectal cancer with liver metastases has historically involved a multidisciplinary approach. In the last several decades, there have been great strides made in the therapeutic options available to treat these patients with advancements in medical, surgical, locoregional and adjunctive therapies available to patients with colorectal liver metastases(CLM). As a result, there have been improvements in patient care and survival. Naturally, the management of CLM has become increasingly complex in coordinating the various aspects of care in order to optimize patient outcomes.

Review

A review of historical and up to date literature was undertaken utilizing Medline/PubMed to examine relevant topics of interest in patients with CLM including criterion for resectability, technical/surgical considerations, chemotherapy, adjunctive and locoregional therapies. This review explores the various disciplines and modalities to provide current perspectives on the various options of care for patients with CLM.

Conclusion

Improvements in modern day chemotherapy as allowed clinicians to pursue a more aggressive surgical approach in the management of stage IV colorectal cancer with CLM. Additionally, locoregional and adjunctive therapies has expanded the armamentarium of treatment options available. As a result, the management of patients with CLM requires a comprehensive, multidisciplinary approach utilizing various modalities and a more aggressive approach may now be pursued in patients with stage IV colorectal cancer with CLM to achieve optimal outcomes.

Curable metastatic colorectal cancer: recommended paradigms

"Cure" for patients with stage IV colorectal cancer remains elusive, but for a growing subset of patients with colorectal liver metastases (CLMs), cure (ie, > 10-year survival without evidence of disease) is achieved in at least 17% of resected patients. Candidates for resection include those with limited and in some cases extensive hepatic disease, and in highly selected cases, patients with extrahepatic disease. Number, size, and bilaterality of CLMs no longer stand as absolute contraindications to surgery. Chemotherapy has further advanced the field of surgery for CLMs, enabling an additional group of patients who present with unresectable disease to undergo surgery after downsizing with chemotherapy. Modern surgical techniques and liver preparation allow resection after chemotherapy, with excellent results. This article summarizes the current multidisciplinary approach to treatment of CLMs. The definition of resectability, conversion of unresectable CLMs to resectable ones, advances in surgical techniques, advances in chemotherapy, and predictors of outcome are detailed.

Hilar cholangiocarcinoma: current management

OBJECTIVE

To review the literature with regard to outcome of surgical management for hilar cholangiocarcinoma (Klatskin tumor).

BACKGROUND

Hilar cholangiocarcinoma is a rare tumor with a poor prognosis. Surgical resection provides the only possibility for cure. Advances in hepatobiliary imaging and surgical strategies to treat this disease have resulted in improved postoperative outcomes.

METHODS

We performed a review of the English literature on hilar cholangiocarcinoma from 1990 to 2007. This review included preoperative evaluation, surgical techniques, issues and controversies in management, prognostic variables, and considerations for future directions.

RESULTS

Complete resection remains the most effective and only potentially curative therapy for hilar cholangiocarcinoma. Negative resection margins are associated with improved outcomes, and major hepatic resections have enhanced the likelihood of R0 resection. Portal vein embolization may be indicated in selected patients before extensive hepatic resection. Staging laparoscopy should be considered to detect occult metastatic disease. Orthotopic liver transplantation might be applicable for a highly selected subgroup.

CONCLUSIONS

Surgical resection including major hepatic resection remains the mainstay of treatment of hilar cholangiocarcinoma. Additional evidence is needed to fully define the role of orthotopic liver transplantation. Improvements in adjuvant therapy are essential for improving long-term outcome.

Prediction of postoperative outcome after hepatectomy with a new bedside test for maximal liver function capacity

OBJECTIVE

To validate the LiMAx test, a new bedside test for the determination of maximal liver function capacity based on C-methacetin kinetics. To investigate the diagnostic performance of different liver function tests and scores including the LiMAx test for the prediction of postoperative outcome after hepatectomy.

SUMMARY BACKGROUND DATA

Liver failure is a major cause of mortality after hepatectomy. Preoperative prediction of residual liver function has been limited so far.

METHODS

Sixty-four patients undergoing hepatectomy were analyzed in a prospective observational study. Volumetric analysis of the liver was carried out using preoperative computed tomography and intraoperative measurements. Perioperative factors associated with morbidity and mortality were analyzed. Cutoff values of the LiMAx test were evaluated by receiver operating characteristic.

RESULTS

Residual LiMAx demonstrated an excellent linear correlation with residual liver volume (r = 0.94, P < 0.001) after hepatectomy. The multivariate analysis revealed LiMAx on postoperative day 1 as the only predictor of liver failure (P = 0.003) and mortality (P = 0.004). AUROC for the prediction of liver failure and liver failure related death by the LiMAx test was both 0.99. Preoperative volume/function analysis combining CT volumetry and LiMAx allowed an accurate calculation of the remnant liver function capacity prior to surgery (r = 0.85, P < 0.001).

CONCLUSIONS

Residual liver function is the major factor influencing the outcome of patients after hepatectomy and can be predicted preoperatively by a combination of LiMAx and CT volumetry.

Current management strategy of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) still remains a considerable challenge for surgeons. Surgery, including liver transplantation, is the most important therapeutic approach for patients with this disease. HCC is frequently diagnosed at advanced stages and has a poor prognosis with a high mortality rate even when surgical resection has been considered potentially curative. This brief report summarizes the current status of the management of this malignancy and includes a short description of new pharmacological approaches in HCC treatment.

Exact CT-based liver volume calculation including nonmetabolic liver tissue in three-dimensional liver reconstruction

Exact preoperative determination of the liver volume is of great importance prior to hepatobiliary surgery, especially in living donated liver transplantation (LDLT) and extended hepatic resections. Modern surgery-planning systems estimate these volumes from segmented image data. In an experimental porcine study, our aim was (1) to analyze and compare three volume measurement algorithms to predict total liver volume, and (2) to determine vessel tree volumes equivalent to nonmetabolic liver tissue. Twelve porcine livers were examined using a standardized three-phase computed tomography (CT) scan and liver volume was calculated computer-assisted with the three different algorithms. After hepatectomy, livers were weighed and their vascular system plasticized followed by CT scan, CT reconstruction and re-evaluation of total liver and vessel volumes with the three different algorithms. Blood volume determined by the plasticized model was at least 1.89 times higher than calculated by multislice CT scans (9.7% versus 21.36%, P=0.028). Analysis of 3D-CT-volumetry showed good correlation between the actual and the calculated liver volume in all tested algorithms with a high significant difference in estimating the liver volume between Heymsfield versus Heidelberg (P=0.0005) and literature versus Heidelberg (P=0.0060). The Heidelberg algorithm reduced the measuring error with deviations of only 1.2%. The present results suggest a safe and highly predictable use of 3D-volumetry in liver surgery for evaluating liver volumes. With a precise algorithm, the volume of remaining liver or single segments can be evaluated exactly and potential operative risks can therefore be better calculated. To our knowledge, this study implies for the first time a blood pool, which corresponds to nonmetabolic liver tissue, of more than 20% of the whole liver volume.

Patients With Initially Unresectable Colorectal Liver Metastases: Is There a Possibility of Cure?

Purpose

Although oncosurgical strategies have demonstrated increased survival in patients with unresectable colorectal liver metastases (CLM), their potential for cure is still questioned. The aim of this study was to evaluate long-term outcome after combining downsizing chemotherapy and rescue surgery and to define prognostic factors of cure.

Patients and Methods

All patients with initially unresectable CLM who underwent rescue surgery and had a minimum follow-up of 5 years were included. Cure was defined as a disease-free interval ≥ 5 years from last hepatic or extrahepatic resection until last follow-up.

Results

Mean age of 184 patients who underwent resection (April 1988 through July 2002) was 56.9 years. Patients had a mean number of 5.3 metastases (bilobar in 76%), associated to extrahepatic disease in 27%. Surgery was possible after one (74%) or more (26%) lines of chemotherapy. Five- and 10-year overall survival rates were 33% and 27%, respectively. Of 148 patients with a follow-up ≥ 5 years, 24 patients (16%) were considered cured (mean follow-up, 118.6 months), six (25%) of whom were considered cured after repeat resection of recurrence. Twelve “cured” patients (50%) had a disease-free interval more than 10 years. Cured patients more often had three or fewer metastases less than 30 mm (P = .03) responding to first-line chemotherapy (P = .05). Multivariate analysis identified maximum size of metastases less than 30 mm at diagnosis, number of metastases at hepatectomy three or fewer, and complete pathologic response as independent predictors of cure.

Conclusion

Cure can be achieved overall in 16% of patients with initially unresectable CLM resected after downsizing chemotherapy. In addition to increased survival, this oncosurgical approach has real potential for disease eradication.

Major hepatic resection for hepatocellular carcinoma with or without portal vein embolization: Perioperative outcome and survival

BACKGROUND

Preoperative portal vein embolization (PVE) is performed to minimize perioperative risks of major hepatic resection for hepatocellular carcinoma (HCC), but its effects on tumor growth are ill defined. Perioperative outcome and survival after major hepatic resection for HCC, with and without PVE, were investigated.

METHODS

Patients that underwent major hepatic resection (> or =3 segments) for HCC between January 1998 and May 2007 were analyzed retrospectively. Preoperative PVE was performed when the remnant liver volume was predicted to be insufficient.

RESULTS

A total of 54 patients underwent major hepatic resection for HCC: 21 patients with PVE before resection (PVE group) and 33 patients without PVE (non-PVE group). PVE and non-PVE groups had similar rates of fibrosis or cirrhosis, hepatitis C virus, hepatitis B virus, American Joint Committee on Cancer stage, preoperative transarterial chemoembolization, overall postoperative complications, and positive margin (P = nonsignificant for all rates). There were no perioperative deaths in the PVE group and 6 (18%) deaths in the non-PVE group (P = .038). Median follow-up was 21 months. Excluding perioperative deaths, overall survival rates at 1, 3, and 5 years were 94%, 82%, and 72%, respectively, in the PVE group and 93%, 63%, and 54%, respectively, in the non-PVE group (P = .35). Similarly, disease-free survival (DFS) rates were not significantly different between the groups, with 1-, 3-, and 5-year DFS rates of 84%, 56%, and 56%, respectively, in the PVE group and 66%, 49%, and 49%, respectively, in the non-PVE group (P = .38).

CONCLUSION

PVE before major hepatic resection for HCC is associated with improved perioperative outcome. Excluding perioperative mortality, overall survival and DFS rates were similar between patients with and without preoperative PVE.

Portal vein embolization in hilar cholangiocarcinoma

In patients with hilar cholangiocarcinoma, extended hepatectomy and caudate lobe resection are often performed to achieve an R0 resection. In patients whose standardized future liver remnant is less than or equal to 20% of total liver volume, portal vein embolization (PVE) should be performed. In patients with biliary dilatation of the future liver remnant, a biliary drainage catheter should be placed before PVE. If the planned surgery is an extended right hepatectomy, segment 4 branch embolization improves the hypertrophy of segments 2 and 3. In high-volume centers, PVE can be safely performed; it increases the resectability rate and results in the same survival rates as those in patients who undergo resection without PVE.

Current management of colorectal hepatic metastasis

In the USA, cancers of the colon and rectum are the third most common site of new cancer cases and cancer deaths. With improved screening and adjuvant therapy, the survival of patients has increased substantially over the last decade. However, patients with metastatic disease often have limited survival. Hepatic metastasis is one of the most frequent sites of metastatic disease. In fact, 35-55% of patients with colorectal cancer will develop hepatic metastasis at some time during the course of their disease. Patients who are able to undergo complete resection of their hepatic metastases have the best chance of long-term survival. The goal of hepatic resection is to achieve complete resection of all metastases with microscopically negative surgical margins while preserving sufficient hepatic parenchyma. Survival following hepatic resection of colorectal metastasis now approaches 35-50%. However, approximately 65% of patients will have a recurrence at 5 years. Increasingly chemotherapeutic agents are being offered in the preoperative setting prior to operation. At the time of operation, patients with extensive hepatic disease can sometimes be offered ablative therapies combined with resection or staged approaches. Modern management of hepatic colorectal metastases necessitates a multidisciplinary approach to effectively treat these patients and increase the number of patients who will benefit from resection.

Can hyperbaric oxygenation decrease doxorubicin hepatotoxicity and improve regeneration in the injured liver?

BACKGROUND/PURPOSE

Portal vein embolization is used in the treatment of hepatocellular cancer, with the purpose of enhancing resectability. However, regeneration is restricted due to hepatocellular injury following chemotherapeutics (e.g. doxorubicin). The aim of this study was to investigate whether hyperbaric oxygenation (HBO) can alleviate the hepatotoxicity of chemotherapy and improve regeneration in the injured liver.

METHODS

Rats were allocated to four experimental groups. Group I rats were subjected to right portal vein ligation (RPVL); rats in groups II and III were administered doxorubicin prior to RPVL, with group III rats being additionally exposed to HBO sessions postoperatively; group IV rats was sham-operated. All rats were sacrificed on postoperative day 7, and liver injury was assessed by measuring alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Protein synthetic ability was determined based albumin levels and liver regeneration by the mitotic index (MI).

RESULTS

The AST and ALT values of group II rats were significantly higher than those of group I, but not those of group III. Rats treated with doxorubicin and HBO (groups II and III) showed slightly but not significant differences in albumin levels than those subjected to only RPVL or sham-operated. The MI was significantly increased in groups I, II, and III, with the MI of group III rats significantly higher than those of group I rats.

CONCLUSIONS

Based on our results, we conclude that HBO treatment has the potential to diminish doxorubicin-related hepatotoxicity and improve regeneration in the injured liver.

Quantitative assessment of hepatic function and its relevance to the liver surgeon

BACKGROUND

Standard evaluation of patients undergoing hepatic surgery has been through radiological and quantitative determination of liver function. As more complex and extensive surgery is now being performed, often in the presence of cirrhosis/fibrosis or following administration of chemotherapy, it is questioned whether additional assessment may be required prior to embarking on such surgery. The aim of this review was to determine the current knowledge base in relation to the performance of quantitative assessment of hepatic function both pre- and post-operatively in patients undergoing hepatic resectional surgery and liver transplantation.

METHODS

An electronic search was performed of the medical literature using the MEDLINE database to identify relevant articles with cross-referencing of all identified papers to ensure full literature capture.

RESULTS AND CONCLUSIONS

The review has identified a number of different methods of dynamically assessing hepatic function, the most frequently performed being through the use of indocyanine green clearance. With the recent and further anticipated developments in hepatic resectional surgery, it is likely that quantitative assessment will become more widely practiced in order to reduce post-operative hepatic failure and improve outcome.

Assessment of liver function for safe hepatic resection

The preoperative assessment of liver function is extremely important for preventing postoperative liver failure and mortality after hepatic resection. Liver function tests may be divided into three types; conventional liver function tests, general scores, and quantitative liver function tests. General scores are based on selected clinical symptoms and conventional test results. Child-Turcotte-Pugh score has been the gold standard for four decades, but the Child-Turcotte-Pugh score has difficulty discriminating a good risk from a poor risk in patients with mild to moderate liver dysfunction. The model for end-stage liver disease score has also been applied to predict short-term outcome after hepatectomy, but it is only useful in patients with advanced cirrhosis. Quantitative liver function tests overcome the drawbacks of general scores. The indocyanine green retention rate at 15 minutes (ICG R15) has been reported to be a significant predictor of postoperative liver failure and mortality. The safety limit of the hepatic parenchymal resection rate can be estimated using the ICG R15, and a decision tree (known as the Makuuchi criteria) for selecting patients and hepatectomy procedures has been proposed. Hepatic resection can be performed with a mortality rate of nearly zero using this decision tree. If the future remnant liver volume does not fulfill the Makuuchi criteria, preoperative portal vein embolization should be performed to prevent postoperative liver failure. Galactosyl human serum albumin-diethylenetriamine-pentaacetic acid scintigraphy also provides data that complement the ICG test. Other quantitative liver function tests, however, require further validation and simplification.

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 results of two-stage hepatectomy for irresectable colorectal cancer liver metastases

OBJECTIVE

To assess feasibility, risks, and long-term outcome of 2-stage hepatectomy as a means to improve resectability of colorectal liver metastases (CLM).

SUMMARY BACKGROUND DATA

Two-stage hepatectomy uses compensatory liver regeneration after a first noncurative hepatectomy to enable a second curative resection.

METHODS

Between October 1992 and January 2007, among 262 patients with initially irresectable CLM, 59 patients (23%) were planned for 2-stage hepatectomy. Patients were eligible when single resection could not achieve complete treatment, even in combination with chemotherapy, portal embolization, or radiofrequency, but tumors could be totally removed by 2 sequential resections. Feasibility and outcomes were prospectively evaluated.

RESULTS

Two-stage hepatectomy was feasible in 41 of 59 patients (69%). Eighteen patients failed to complete the second hepatectomy because of disease progression (n = 17) or bad performance status (n = 1). The 41 successfully treated patients had a mean number of 9.1 metastases (mean diameter, 48.5 mm at diagnosis). Chemotherapy was delivered before (95%), in between (78%), and after (78%) the 2 hepatectomies. Mean delay between the 2 liver resections was 4.2 months. Postoperative mortality was 0% and 7% (3/41) after the first and second hepatectomy, respectively. Morbidity rates were also higher after the second procedure (59% vs. 20%) (P < 0.001). Five-year survival was 31% on an intention to treat basis, and all but 2 patients who did not complete the 2-stage strategy died within 19 months. After a median follow-up of 24.4 months (range, 3.7-130.3), overall 3- and 5-year survivals for patients that completed both hepatectomies were 60% and 42%, respectively, after the first hepatectomy (median survival, 42 months from first hepatectomy and 57 months from metastases diagnosis). Disease-free survivals were 26% and 13% at 3 and 5 years, respectively.

CONCLUSIONS

Two-stage hepatectomy provides a 5-year survival of 42% and a hope of long-term survival for selected patients with extensive bilobar CLM, irresectable by any other means.

Volumetric and functional recovery of the remnant liver after major liver resection with prior portal vein embolization : recovery after PVE and liver resection

INTRODUCTION

Portal vein embolization is an accepted method to increase the future remnant liver preoperatively. The aim of this study was to assess the effect of preoperative portal vein embolization on liver volume and function 3 months after major liver resection.

MATERIALS AND METHODS

This is a retrospective case-control study. Data were collected of patients who underwent portal vein embolization prior to (extended) right hemihepatectomy and of control patients who underwent the same type of resection without prior portal vein embolization. Liver volumes were measured by computed tomography volumetry before portal vein embolization, before liver resection, and 3 months after liver resection. Liver function was assessed by hepatobiliary scintigraphy before and 3 months after liver resection.

RESULTS

Ten patients were included in the embolization group and 13 in the control group. Groups were comparable for gender, age, and number of patients with a compromised liver. The mean future remnant liver volume was 33.0 +/- 8.0% prior to portal vein embolization in the embolization group and 45.6 +/- 9.1% in the control group (p < 0.01). Prior to surgery, there were no significant differences in future remnant liver volume and function between the groups. Three months postoperatively, the mean remnant liver volume was 81.9 +/- 8.9% of the initial total liver volume in the embolization group and 79.4 +/- 11.0% in the control group (p > 0.05). Remnant liver function increased up to 88.1 +/- 17.4% and 83.3 +/- 14% respectively of the original total liver function (p > 0.05).

CONCLUSION

Preoperative portal vein embolization does not negatively influence postoperative liver regeneration assessed 3 months after major liver resection.

Liver failure after major hepatic resection

INTRODUCTION

The consequence of excessive liver resection is the inexorable development of progressive liver failure characterised by the typical stigmata associated with this condition, including worsening coagulopathy, hyperbilirubinaemia and encephalopathy. The focus of this review will be to investigate factors contributing to hepatocyte loss and impaired regeneration.

METHODS

A literature search was undertaken of Pubmed and related search engines, examining for articles relating to hepatic failure following major hepatectomy.

RESULTS

In spite of improvements in adjuvant chemotherapy and increasing surgical confidence and expertise, the parameters determining how much liver can be resected have remained largely unchanged. A number of preoperative, intraoperative and post-operative factors all contribute to the likelihood of liver failure after surgery.

CONCLUSIONS

Given the magnitude of the surgery, mortality and morbidity rates are extremely good. Careful patient selection and preservation of an obligate volume of remnant liver is essential. Modifiable causes of hepatic failure include avoidance of sepsis, drainage of cholestasis with restoration of enteric bile salts and judicious use of portal triad inflow occlusion intra-operatively. Avoidance of post-operative sepsis is most likely to be achieved by patient selection, meticulous intra-operative technique and post-operative care. Modulation of portal vein pressures post-operatively may further help reduce the risk of liver failure.

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.

Current concept of small-for-size grafts in living donor liver transplantation

The extended application of living donor liver transplantation (LDLT) has revealed the problem of graft size mismatching called "small-for-size (SFS) graft syndrome." The initial trials to resolve this problem involved increasing the procured graft size, from left to right, and even extension to include a right lobe graft. Clinical cases of living right lobe donations have been reported since then, drawing attention to the risks of increasing the liver volume procured from a living donor. However, not only other modes of increasing graft volume such as auxiliary or dual liver transplantation, but also control of the increased portal pressure caused by an SFS graft, such as a portosystemic shunt or splenectomy, have been trialed with some positive results. To establish an effective strategy for transplanting SFS grafts and preventing SFS graft syndrome, it is essential to have precise knowledge and tactics to evaluate graft quality and graft volume, when performing these LDLTs with portal pressure control. We reviewed the updated literature on the pathogenesis of and strategies for using SFS grafts.

A new measure to assess the difficulty of liver resection

BACKGROUND

There is no valid measure to assess surgical difficulty and feasibility of a planned liver resection. It is the objective of this study to evaluate a mathematical measure from a 3D graphical analysis.

METHODS

Eleven different 3D models of hepatic tumours were evaluated by experts for resectability and analysed with Amira graphic software taking into consideration the portal and hepatic venous vascular relationships. Virtual resection volumes with increasing resection margins from 1 to 30 mm were determined separately for portal veins, hepatic veins, their intersections and volume unions. The integral of the increasing resection volumes was defined as risk coefficient. The risk coefficients from this volumetric analysis were compared with the expert opinion.

RESULTS

The risk coefficient based on the integral of portal venous and hepatic venous volume unions reproduced the expert opinion highly significantly (correlation coefficient 0.9, p<0.05) and more accurately than volumetric analysis of the planned resection margin.

CONCLUSION

With automated volumetric analysis, anatomically problematic situations in liver surgery can be reproduced and scaled. The risk coefficient obtained is a suitable objective measure for defining risk areas in liver surgery.

Risk factors of liver dysfunction after extended hepatic resection in biliary tract malignancies

BACKGROUND

Postoperative hepatic insufficiency is a critical complication after extended hepatic resection in patients with biliary tract malignancies, the majority of whom suffer from obstructive jaundice. The aim of this study was to assess clinical parameters linked to this type of liver dysfunction.

METHODS

A total of 111 patients were retrospectively reviewed. Patient background, pre- and intraoperative parameters, and a ratio of remnant liver volume/entire liver volume (RLV/ELV) as a volumetric parameter were compared between patients with and without postoperative hyperbilirubinemia and subsequent fatal outcome.

RESULTS

Logistic regression indicated that only RLV/ELV ratio was an independent factor influencing postoperative hyperbilirubinemia, and RLV/ELV ratio and indocyanine green retention rate at 15 minutes (ICG-R15) were factors affecting survival. Patients with RLV/ELV less than 40% had 7.6 times the risk of postoperative hyperbilirubinemia, while no patients with RLV/ELV greater than 40% and ICG-R15 less than 25% died of liver failure.

CONCLUSIONS

The RLV/ELV ratio was the factor with the greatest impact on liver dysfunction after extended hepatectomy in patients with biliary tract malignancies.

Potentially curable metastatic colorectal cancer

Although patients with metastatic colorectal cancer have historically had a uniformly dismal prognosis, recent advances in chemotherapeutics and surgical techniques allow many patients to be treated with the potential for long-term survival and cure. Patients with potentially curable disease are those in whom multidisciplinary strategies including surgery can result in safe resection of all metastatic disease with negative margins. Although favorable outcomes using such strategies can increasingly be predicted, the presence of poor prognostic factors does not necessarily represent a contraindication to the use of a potentially curative strategy as long as a margin-negative resection can ultimately be obtained. Further analysis of the innovative strategies and techniques described in this article are needed to maximize cure rates in patients with this disease.

Staging of advanced colorectal cancer

The management of advanced colorectal cancer has changed dramatically during the last decade. By redefining resectability, and with the use of modern chemotherapy, nearly 10% of unresectable patients are now alive 5 years after diagnosis, and, overall, 20% are alive at 5 years when the combined results of surgery and chemotherapy are considered. These achievements are not reflected in the current staging, which categorizes all disease spread beyond the lymph node basin of the primary tumor as unstratified stage 4. This article discusses the merits of a number of proposals for a new, meaningful staging system for advanced colorectal cancer.

Is embolization of segment 4 portal veins before extended right hepatectomy justified?

BACKGROUND

Preoperative portal vein embolization (PVE) is increasingly used as a preparation for major hepatectomy in patients with inadequate liver remnant volume or function. However, whether segment 4 (S4) portal veins should be embolized is controversial. The effect of S4 PVE on the volume gain of segments 2 and 3 (S2+3) was examined.

METHODS

Among 73 patients with uninjured liver who underwent right portal vein embolization (RPVE, n = 15) or RPVE extended to S4 portal veins (RPVE+4, n = 58), volume changes in S2+3 and S4 after embolization were compared. Clinical outcomes and PVE complications were assessed.

RESULTS

After a median of 27 days, the S2+3 volume increased significantly after both RPVE and RPVE+4, but the absolute increase was significantly higher for RPVE+4 (median, 106 mL vs 141 mL; P = .044), as was the hypertrophy rate (median, 26% vs 54%; P = .021). There was no significant difference between RPVE and RPVE+4 in the absolute S4 volume increase (52 mL for RPVE vs 55 mL for RPVE+4; P = .61) or the hypertrophy rate of S4 (30% for RPVE vs 26% for RPVE+4; P = .45). Complications of PVE occurred in 1 patient (7%) after RPVE and 6 (10%) after RPVE+4 (P > .99). No PVE complication precluded subsequent resection. Curative hepatectomy was performed in 13 patients (87%) after RPVE and 40 (69%) after RPVE+4 (P = .21).

CONCLUSIONS

RPVE+4 significantly improves S2+3 hypertrophy compared with RPVE alone. Extending RPVE to S4 does not increase PVE-associated complications.

Chemotherapy with bevacizumab does not affect liver regeneration after portal vein embolization in the treatment of colorectal liver metastases

BACKGROUND

Blockage of vascular endothelial growth factor (VEGF) in murine models has been shown to impair liver regeneration after partial hepatectomy. The aim of this study was to evaluate the effects of chemotherapy with or without bevacizumab (monoclonal antibody anti-VEGF) on liver regeneration after portal vein embolization (PVE) in the treatment of colorectal liver metastases and its possible effect on postoperative outcome after major liver resection.

METHODS

Records of 65 consecutive patients treated with or without preoperative chemotherapy (with or without bevacizumab) and PVE for colorectal liver metastases from September 1995 to February 2007 were reviewed from a prospective database. Future liver remnant (FLR) volume, degree of FLR hypertrophy after PVE, morbidity, mortality, and survival were analyzed.

RESULTS

Preoperative PVE was performed after chemotherapy in 43 patients and without chemotherapy in 22 patients. Among the 43 patients treated with chemotherapy, 26 received concurrent bevacizumab. After a median of 4 weeks after PVE, there was no difference in FLR volume increase among patients treated with or without chemotherapy. Similarly, there was no statistically significant difference in degree of FLR hypertrophy among patients treated without (mean, 10.1%) or with chemotherapy, with or without bevacizumab (8.8% and 6.8%) (P = .11). Forty-eight (74%) of 65 patients underwent extended right or right hepatectomy after PVE. No differences in morbidity and mortality were observed among patients treated with or without preoperative chemotherapy (with or without bevacizumab).

CONCLUSION

Preoperative chemotherapy with bevacizumab does not impair liver regeneration after PVE. Liver resection can be performed safely in patients treated with bevacizumab before PVE.

Improved survival following right trisectionectomy with caudate lobectomy without operative mortality: surgical treatment for hilar cholangiocarcinoma

BACKGROUND

We conducted this study to assess the safety of performing right trisectionectomy with caudate lobectomy for hilar cholangiocarcinoma by analyzing postoperative mortality and morbidity, and to evaluate the effect of such procedure on pathological curability and long-term overall survival.

METHODS

A retrospective clinicopathological analysis was performed for 16 hilar cholangiocarcinoma patients who underwent right trisectionectomy with caudate lobectomy from June 1999 to April 2003. The median follow-up period was 36.9 months. The preoperative Bismuth-Corlette type was type II in four patients, type III(A) in 10 patients, and type IV in two patients.

RESULTS

The median liver volume after hepatic resection was 21.9% of the total liver volume. Postoperative complications including one chronic liver failure developed in 12 patients, but no in-hospital deaths occurred. A postoperative pathological examination showed a cancer free margin in all of the proximal resection sites, although three cases had carcinoma in situ (CIS) lesions in the distal margin that were confirmed during surgery. The 1-, 3-, and 5-year overall survival rates were 94.1%, 64.2%, and 64.2%, respectively.

CONCLUSION

We obtained excellent survival rates without any in-hospital deaths following right trisectionectomy with caudate lobectomy. This procedure may be an effective surgical procedure that can be executed to achieve low mortality rate and high pathological curability for hilar cholangiocarcinomas, except for Bismuth type III(B).

Selection criteria for liver resection in patients with hepatocellular carcinoma and chronic liver disease

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide with an annual occurrence of one million new cases. An etiologic association between HBV infection and the development of HCC has been established with a relative risk 200-fold greater than in non-infected individuals. Hepatitis C virus is also proving an important predisposing factor for this malignancy with an incidence rate of 7% at 5 years and 14% at 10 years. The prognosis depends on tumor stage and degree of liver function, which affect the tolerance to invasive treatments. Although surgical resection is generally accepted as the treatment of choice for HCC, new treatment strategies, such as local ablative therapies, transarterial embolization and liver transplantation, have been developed nowadays. With increasing detection of small HCCs from screening programs for cirrhotic patients, it is foreseen that locoregional therapy will play an important role in the near future.

Comparative study of portal vein embolization versus portal vein ligation for induction of hypertrophy of the future liver remnant using a mini-pig model

SUMMARY BACKGROUND DATA

The extent of hepatectomies is limited by the functional reserve of the remnant liver. The introduction of preoperative portal vein occlusion techniques to induce a preoperative hyperplasia of the future liver remnant has reduced the risk of postoperative liver failure. However, it has remained a matter of debate whether partial portal vein embolization (PVE) or suture ligation of the portal branches during exploration is the preferred technique. We compared both techniques under standardized experimental conditions in a large animal model by means of effectiveness and pathophysiologic differences.

METHODS

Thirteen mini-pigs underwent portal vein ligation (PVL), 11 mini-pigs underwent PVE of 75% of the liver volume, and 6 underwent a sham operation. The animals were killed after 28 days. Laboratory liver function and damage parameters, lobar liver-to-body weight indices, portal and arterial flow alterations, and histologic changes were assessed. Ex situ arteriograms and portograms were performed to examine adaptive changes in the macroarchitecture of both vascular systems.

RESULTS

The liver-to-body weight index of the nonoccluded lobe was highest after PVE (0.85) versus 0.6 (P < 0.05) after PVL. There was no significant reduction in global serum parameters reflecting total liver function. After 4 weeks, the PVL group consistently exhibited hepatopetal portal flow in the ligated lobes, which was present but significantly decreased after PVE. The ex situ angiography after PVE and PVL revealed the development of portal neocollaterals in the portal-occluded liver parts.

CONCLUSIONS

Both PVL and PVE are able to induce hypertrophy of the future liver remnant. In comparison, PVE is the more effective technique to increase the future liver remnant. This is due to a more effective, durable occlusion of the portal branches. Formation of collaterals between occluded and nonoccluded liver parts seems to be the cause of inferior regeneration in the ligation group.

Expanding criteria for resectability of colorectal liver metastases

Surgical resection is the treatment of choice in patients with colorectal liver metastases, with 5-year survival rates reported in the range of 40%-58%. Over the past 10 years, there has been an impetus to expand the criteria for defining resectability for patients with colorectal metastases. In the past, such features as the number of metastases (three to four), the size of the tumor lesion, and a mandatory 1-cm margin of resection dictated who was "resectable." More recently, the criteria for resectability have been expanded to include any patient in whom all disease can be removed with a negative margin and who has adequate hepatic volume/reserve. Specifically, instead of resectability being defined by what is removed, decisions concerning resectability now center around what will remain after resection. Under this new paradigm, the number of patients with resectable disease can be expanded by increasing/preserving hepatic reserve (e.g., portal vein embolization, two-stage hepatectomy), combining resection with ablation, and decreasing tumor size (preoperative chemotherapy). The criteria for resectability have also expanded to include patients with extrahepatic disease. Rather than being an absolute contraindication to surgery, patients with both intra- and extrahepatic disease should potentially be considered for resection based on strict selection criteria. The expansion of criteria for resectability of colorectal liver metastases requires a much more nuanced and sophisticated approach to the patient with advanced disease. A therapeutic approach that includes all aspects of multidisciplinary and multimodality care is required to select and treat this complex group of patients.

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.

Cholangiocarcinoma

Cholangiocarcinoma is a primary hepatic malignancy originating from bile duct epithelium. It is the second most common primary hepatic neoplasia, and its incidence has increased within the last 3 decades. Although several risk factors have been identified, especially chronic biliary tract inflammation, most patients with cholangiocarcinoma have no identifiable risk factors. Recent developments in radiologic and molecular diagnostic methods have helped in the diagnosis of this disease. The only curative therapy is surgical resection or liver transplantation. For patients with advanced stage disease, survival remains limited. With growing understanding of the molecular and cellular etiology of this disease, new targeted therapies are being developed.

Postoperative liver dysfunction and future remnant liver: where is the limit? Results of a prospective study

BACKGROUND

The future remnant liver (FRL) limit for safe major hepatectomy with low risk of postoperative liver failure has not yet been well defined.

METHODS

Between April 2000 and September 2004, every patient scheduled for major hepatectomy in our institution underwent CT-volumetry of FRL. Patients with FRL <25% underwent portal vein embolization (PVE). Exclusion criteria were PVE, associated vascular resection and liver cirrhosis. The FRL was correlated with short-term results in patients with normal liver (group A) and those with impaired liver function secondary to neoadjuvant chemotherapy or cholestasis (bilirubin >2 mg/100 ml) (group B). Liver dysfunction was defined as both PT <50% and serum bilirubin level >5 mg/100 ml for three or more consecutive days.

RESULTS

A total of 119 patients were analyzed, 72 in group A and 47 in group B. The FRL value was the only significant risk factor for postoperative liver dysfunction in the univariate and multivariate analysis (p = 0.009). The FRL did not correlate with postoperative mortality and morbidity. Bilirubin and prothrombin time (PT) on days 3 and 7 were significantly correlated to FRL in both groups. In group A, patients with postoperative liver dysfunction had a FRL<30% (3 versus 0; p = 0.005). According to receiving operator characteristic (ROC) curve analysis, a FRL value of 26.5% predicted postoperative liver dysfunction with 66.7% sensitivity, 97.1% specificity, 50% positive predictive value (PPV), and 98.5% negative predictive value (NPV). In group B, patients with postoperative liver dysfunction had a FRL <35% (4 versus 0; p = 0.027). According to ROC curve analysis, a FRL value of 31.05% predicted postoperative liver dysfunction with 75% sensitivity, 79.1% specificity, 25% PPV, and 97.1% NPV.

CONCLUSIONS

Hepatectomy can be considered safe when FRL is >26.5% in patients with healthy liver and >31% in patients with impaired liver function.

Comparison of two methods of future liver remnant volume measurement

BACKGROUND

In liver transplantation, a minimum graft to patient body weight (BW) ratio is required for graft survival; in liver resection, total liver volume (TLV) calculated from body surface area (BSA) is used to determine the future liver remnant (FLR) volume needed for safe hepatic resection. These two methods of estimating liver volume have not previously been compared. The purpose of this study was to compare FLR volumes standardized to BW versus BSA and to assess their utility in predicting postoperative hepatic dysfunction after hepatic resection.

METHODS

Records were reviewed of 68 consecutive noncirrhotic patients who underwent major hepatectomy after portal vein embolization between 1998 and 2006. FLR (cubic centimeter) was measured preoperatively with three-dimensional helical computed tomography; TLV (cubic centimeter) was calculated from the patients' BSA. The relationship between FLR/TLV and FLR/BW (cubic centimeter per kilogram) was examined using linear regression analysis. Receiver operating characteristic (ROC) curve analysis was used to determine FLR/TLV and FLR/BW cutoff values for predicting postoperative hepatic dysfunction (defined as peak bilirubin level>3 mg/dl or prothrombin time>18 s).

RESULTS

Regression analysis revealed that the FLR/TLV and FLR/BW ratios were highly correlated (Pearson correlation coefficient, 0.98). The area under the ROC curve was 0.85 for FLR/TLV and 0.84 for FLR/BW (95% confidence interval, 0.71-0.97). Sixteen of the 68 patients developed postoperative hepatic dysfunction. The ROC curve analysis yielded a cutoff FLR/BW value of <or=0.4, which had a positive predictive value (PPV) of 78% and a negative predictive value (NPV) of 85%. The corresponding FLR/TLV cutoff value of <or=20% had a PPV of 80% and a NPV of 86%.

CONCLUSIONS

Based on the strong correlation between the FLR measurements standardized to BW and BSA and their similar ability to predict postoperative hepatic dysfunction, both methods are appropriate for assessing liver volume. In noncirrhotic patients, a FLR/BW ratio of <or=0.4 and FLR/TLV of <or=20% provide equivalent thresholds for performing safe hepatic resection.