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

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.

Portal vein embolization before right hepatectomy: prospective clinical trial

OBJECTIVE

To assess the impact of liver hypertrophy of the future liver remnant volume (FLR) induced by preoperative portal vein embolization (PVE) on the immediate postoperative complications after a standardized major liver resection.

SUMMARY BACKGROUND DATA

PVE is usually indicated when FLR is estimated to be too small for major liver resection. However, few data exist regarding the exact quantification of sufficient minimal functional hepatic volume required to avoid postoperative complications in both patients with or without chronic liver disease.

METHODS

All consecutive patients in whom an elective right hepatectomy was feasible and who fulfilled the inclusion and exclusion criteria between 1998 and 2000 were assigned to have alternatively either immediate surgery or surgery after PVE. Among 55 patients (25 liver metastases, 2 cholangiocarcinoma, and 28 hepatocellular carcinoma), 28 underwent right hepatectomy after PVE and 27 underwent immediate surgery. Twenty-eight patients had chronic liver disease. FLR and estimated rate of functional future liver remnant (%FFLR) volumes were assessed by computed tomography.

RESULTS

The mean increase of FLR and %FFLR 4 to 8 weeks after PVE were respectively 44 +/- 19% and 16 +/- 7% for patients with normal liver and 35 +/- 28% and 9 +/- 3% for those with chronic liver disease. All patients with normal liver and 86% with chronic liver disease experienced hypertrophy after PVE. The postoperative course of patients with normal liver who underwent PVE before right hepatectomy was similar to those with immediate surgery. In contrast, PVE in patients with chronic liver disease significantly decreased the incidence of postoperative complications as well as the intensive care unit stay and total hospital stay after right hepatectomy.

CONCLUSIONS

Before elective right hepatectomy, the hypertrophy of FLR induced by PVE had no beneficial effect on the postoperative course in patients with normal liver. In contrast, in patients with chronic liver disease, the hypertrophy of the FLR induced by PVE decreased significantly the rate of postoperative complications.

Portal vein embolization before right hepatectomy: prospective clinical trial

OBJECTIVE

To assess the impact of liver hypertrophy of the future liver remnant volume (FLR) induced by preoperative portal vein embolization (PVE) on the immediate postoperative complications after a standardized major liver resection.

SUMMARY BACKGROUND DATA

PVE is usually indicated when FLR is estimated to be too small for major liver resection. However, few data exist regarding the exact quantification of sufficient minimal functional hepatic volume required to avoid postoperative complications in both patients with or without chronic liver disease.

METHODS

All consecutive patients in whom an elective right hepatectomy was feasible and who fulfilled the inclusion and exclusion criteria between 1998 and 2000 were assigned to have alternatively either immediate surgery or surgery after PVE. Among 55 patients (25 liver metastases, 2 cholangiocarcinoma, and 28 hepatocellular carcinoma), 28 underwent right hepatectomy after PVE and 27 underwent immediate surgery. Twenty-eight patients had chronic liver disease. FLR and estimated rate of functional future liver remnant (%FFLR) volumes were assessed by computed tomography.

RESULTS

The mean increase of FLR and %FFLR 4 to 8 weeks after PVE were respectively 44 +/- 19% and 16 +/- 7% for patients with normal liver and 35 +/- 28% and 9 +/- 3% for those with chronic liver disease. All patients with normal liver and 86% with chronic liver disease experienced hypertrophy after PVE. The postoperative course of patients with normal liver who underwent PVE before right hepatectomy was similar to those with immediate surgery. In contrast, PVE in patients with chronic liver disease significantly decreased the incidence of postoperative complications as well as the intensive care unit stay and total hospital stay after right hepatectomy.

CONCLUSIONS

Before elective right hepatectomy, the hypertrophy of FLR induced by PVE had no beneficial effect on the postoperative course in patients with normal liver. In contrast, in patients with chronic liver disease, the hypertrophy of the FLR induced by PVE decreased significantly the rate of postoperative complications.

Selective approach to major hepatic resection for hepatocellular carcinoma in chronic liver disease

For large HCCs, partial liver resection remains the best therapeutic option for cure because neither liver transplantation nor percutaneous treatments are indicated. In specialized centers, a better selection of at-risk patients and technical procedures, including the use of intermittent inflow occlusion and the anterior approach, have contributed to improve dramatically the outcome of major liver resection for HCC in CLD. In addition, portal vein embolization has become an important tool to hypertrophy the future liver remnant before major liver resection in cirrhotic patients with apparently normal liver function.

Extended hepatic resection for hepatocellular carcinoma in patients with cirrhosis: is it justified?

OBJECTIVE

To evaluate the perioperative outcomes and long-term survival of extended hepatic resection for hepatocellular carcinoma (HCC) in patients with cirrhosis.

SUMMARY BACKGROUND DATA

Hepatic resection is a well-established treatment for HCC in cirrhotic patients with preserved liver function and limited disease. However, the role of extended hepatic resection (more than four segments) for HCC in cirrhotic patients has not been elucidated.

METHODS

Between 1993 and 2000, 45 consecutive patients with histologically confirmed cirrhosis underwent right or left extended hepatectomy for HCC (group A). Perioperative outcomes and long-term survival of these patients were compared with 161 patients with HCC and cirrhosis who underwent hepatic resection of a lesser extent in the same period (group B). All clinicopathologic and follow-up data were collected prospectively.

RESULTS

Group A patients had significantly higher intraoperative blood loss, longer operation time, and longer hospital stay than group B. However, the two groups were similar in overall morbidity and hospital mortality. There were no significant differences in the incidence of liver failure or other complications. The resection margin width was similar between the two groups. Despite significantly larger tumor size in group A compared with group B, long-term survival was comparable between the two groups.

CONCLUSIONS

Extended hepatic resection for HCC can be performed in selected cirrhotic patients with acceptable morbidity, mortality, and long-term survival that are comparable to those of lesser hepatic resection. Extended hepatectomy for large HCC extending from one lobe to the other or central HCC critically related to the hepatic veins is justifiable in cirrhotic patients with preserved liver function and adequate liver remnant.

Extended hepatic resection for hepatocellular carcinoma in patients with cirrhosis: is it justified?

OBJECTIVE

To evaluate the perioperative outcomes and long-term survival of extended hepatic resection for hepatocellular carcinoma (HCC) in patients with cirrhosis.

SUMMARY BACKGROUND DATA

Hepatic resection is a well-established treatment for HCC in cirrhotic patients with preserved liver function and limited disease. However, the role of extended hepatic resection (more than four segments) for HCC in cirrhotic patients has not been elucidated.

METHODS

Between 1993 and 2000, 45 consecutive patients with histologically confirmed cirrhosis underwent right or left extended hepatectomy for HCC (group A). Perioperative outcomes and long-term survival of these patients were compared with 161 patients with HCC and cirrhosis who underwent hepatic resection of a lesser extent in the same period (group B). All clinicopathologic and follow-up data were collected prospectively.

RESULTS

Group A patients had significantly higher intraoperative blood loss, longer operation time, and longer hospital stay than group B. However, the two groups were similar in overall morbidity and hospital mortality. There were no significant differences in the incidence of liver failure or other complications. The resection margin width was similar between the two groups. Despite significantly larger tumor size in group A compared with group B, long-term survival was comparable between the two groups.

CONCLUSIONS

Extended hepatic resection for HCC can be performed in selected cirrhotic patients with acceptable morbidity, mortality, and long-term survival that are comparable to those of lesser hepatic resection. Extended hepatectomy for large HCC extending from one lobe to the other or central HCC critically related to the hepatic veins is justifiable in cirrhotic patients with preserved liver function and adequate liver remnant.

Portal vein embolization vs. portal vein ligation for induction of hypertrophy of the future liver remnant

The objective of this study was to assess the efficacy of right portal vein embolization (PVE) vs. right portal vein ligation (PVL) for induction of hypertrophy of the left lateral liver lobe before extended right hepatectomy. Thirty-four patients with primary or secondary liver tumors and estimated remnant functional liver parenchyma of less than 0.5% of body weight underwent either right PVE (transcutaneous, n = 10; transileocolic, n = 7) or right PVL (n = 17). Liver volume was assessed by CT scan before occlusion of the right portal vein and prior to resection. There were no deaths. The morbidity rate in each group was 5.8% (PVE, 1 abscess; PVL, 1 bile leak). The increase in liver volume was significantly higher after PVE compared with PVL (188 +/- 81 ml vs. 123 +/- 58 ml) (P = 0.012). Postoperative hospital stay was significantly shorter after PVE in comparison to PVL (4 +/- 2.9 days vs. 8.1 +/- 5.1 days; P < 0.01). Curative liver resection was performed in 10 of 17 patients after PVE and 11 of 17 patients after PVL. PVE and PVL were found to be feasible and safe methods of increasing the remnant functional liver volume and achieving resectability for extended liver tumors. PVE results in a significantly more efficient increase in liver volume and a shorter hospital stay.

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

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

Transhepatic portal vein embolization: anatomy, indications, and technical considerations

Portal vein embolization (PVE) is increasingly being accepted as a useful procedure in the preoperative treatment of patients selected for major hepatic resection. PVE is performed via either the percutaneous transhepatic or the transileocolic route and is usually reserved for patients whose future liver remnants are too small to allow resection. It is a safe and effective method for inducing selective hepatic hypertrophy of the nondiseased portion of the liver and may thereby reduce complications and shorten hospital stays after resection. A thorough knowledge of hepatic segmentation and portal venous anatomy is essential before performing PVE. In addition, the indications and contraindications for PVE, the methods for assessing hepatic lobar hypertrophy, the means of determining optimal timing of resection, and the possible complications of PVE need to be fully understood before undertaking the procedure. Technique may vary among operators, and further research is necessary to determine the best embolic agents available and the expected rates of liver regeneration for PVE. Nevertheless, as hepatobiliary surgeons become more experienced at performing extended hepatic resections, PVE may be requested more frequently.

Evaluation of the effect of age on functioning hepatocyte mass and liver blood flow using liver scintigraphy in preoperative estimations for surgical patients: comparison with CT volumetry

BACKGROUND

The effect of age on functioning hepatocyte mass and liver blood flow was examined using (99m)Tc-galactosyl-human serum albumin (GSA) liver scintigraphy in patients with liver tumors awaiting surgery.

MATERIALS AND METHODS

Seventy-two patients with liver tumors, but normal liver parenchyma, were included in this study; patients with compromised hepatic blood flow as a result of vascular invasion or thrombus were excluded. The liver volume, calculated liver volume, and liver blood flow index (K value) were preoperatively determined by liver scintigraphy using GSA. These three parameters and liver volume measured by computed tomography volumetry (CT-LV) and the standard liver volume (ST-LV), calculated from the patient's body surface area, were examined for correlations with the patient's age. The K value was compared with the indocyanine green dye retention rate, and both sets of results were examined for correlation with the patient's age.

RESULTS

Both the CT-LV and the ST-LV decreased with age, resulting in an unchanged CT-LV/ST-LV ratio with aging. The liver volume and calculated liver volume measured by scintigraphy both decreased with age, even when body size was taken into account. Therefore, in elderly patients, the liver was not morphologically smaller, but the hepatocyte mass in the liver decreased. Furthermore, liver blood flow per unit of functional liver volume determined from the blood flow index did not change with age.

CONCLUSIONS

These results, suggesting a discrepancy between liver volume estimated by CT and actual functioning hepatocyte volume in the elderly, may have a critical impact on preoperative liver functional reserve evaluation prior to hepatic resection in elderly patients.

Hepatic vein reconstruction for resection of hepatic tumors

SUMMARY BACKGROUND DATA

Involvement of the hepatic veins requiring reconstruction has traditionally been considered a contraindication to resection for advanced tumors of the liver because the surgical risks are high and the long-term prognosis poor. Recent advances in liver surgery gleaned from split and live donor liver transplantation that necessitate hepatic vein reconstruction can be applied to hepatic resection in some cases.

METHODS

Sixteen patients who underwent hepatic resection requiring hepatic vein reconstruction from 1996-2001 were reviewed. The mean age was 43 years (range 2-61). Nine patients were resected for hepatocellular carcinoma (HCC), five patients for colorectal metastases, and one patient each for hepatoblastoma and cholangiocarcinoma. In six patients with HCC and cirrhosis, the right hepatic vein was reconstructed to provide venous outflow to liver segments not adequately drained by a remaining major hepatic vein. Four of these six patients required the use of Gore-Tex (W. L. Gore & Associates, Inc., Newark, DE) interposition grafts. In the 10 other cases the entire venous outflow from the remnant liver was reconstructed or reimplanted into the inferior vena cava primarily (n = 8) or using segments of the portal vein from the resected side of the liver as a graft (n = 2). Ex-vivo procedures with the use of veno-venous bypass were required in two cases and in-situ cold perfusion of the liver was used in one case.

RESULTS

There were two perioperative deaths (12%). One patient died of liver failure 3 weeks after right trisegmentectomy with reconstruction of the left hepatic vein and one patient died at 3 months after resection due to sepsis from a segment of small bowel that perforated into a diaphragmatic hernia. Four patients had evidence of postoperative liver failure that resolved with supportive management and one patient required temporary dialysis. All vascular reconstructions were patent at last followup. With median followup of 23 months, 3 patients have died of recurrent malignancy at 14, 18 and 30 months, while an additional patient went on to die of progressive liver failure at 22 months. Actuarial 1 and 3 year survival was 88% and 50% respectively.

CONCLUSION

Hepatic vein involvement by hepatic malignancy does not necessarily preclude resection. Liver resection with reconstruction of the hepatic veins can be performed in selected cases. The increased risk associated with the procedure appears to be balanced by the possible benefits, particularly when the lack of alternative curative approaches is considered.

Resection of liver tumors: technical aspects

The resection of primary and secondary liver tumors has become accepted as the only curative therapy that can be offered to patients with these cancers. Technical advances made over the last two decades have improved the ability of the surgeon to perform these procedures with decreased morbidity. This article reviews hepatic anatomy, the preoperative evaluation of patients and various technical aspects involved in liver resections. The latter includes the role of intraoperative ultrasound and techniques of vascular occlusion and hepatic parenchymal dissection.

Body surface area and body weight predict total liver volume in Western adults

Computed tomography (CT) is used increasingly to measure liver volume in patients undergoing evaluation for transplantation or resection. This study is designed to determine a formula predicting total liver volume (TLV) based on body surface area (BSA) or body weight in Western adults. TLV was measured in 292 patients from four Western centers. Liver volumes were calculated from helical computed tomographic scans obtained for conditions unrelated to the hepatobiliary system. BSA was calculated based on height and weight. Each center used a different established method of three-dimensional volume reconstruction. Using regression analysis, measurements were compared, and formulas correlating BSA or body weight to TLV were established. A linear regression formula to estimate TLV based on BSA was obtained: TLV = -794.41 + 1,267.28 x BSA (square meters; r(2) = 0.46; P <.0001). A formula based on patient weight also was derived: TLV = 191.80 + 18.51 x weight (kilograms; r(2) = 0.49; P <.0001). The newly derived TLV formula based on BSA was compared with previously reported formulas. The application of a formula obtained from healthy Japanese individuals underestimated TLV. Two formulas derived from autopsy data for Western populations were similar to the newly derived BSA formula, with a slight overestimation of TLV. In conclusion, hepatic three-dimensional volume reconstruction based on helical CT predicts TLV based on BSA or body weight. The new formulas derived from this correlation should contribute to the estimation of TLV before liver transplantation or major hepatic resection.

Liver imaging. A surgeon's perspective

Advances in the diagnosis and treatment of liver lesions have improved therapy for a broad range of clinical conditions, many of which could not be effectively treated in the recent past. These advances are the result of better surgical techniques as well as diagnostic imaging. This article discusses the anatomy of the liver and the clinical evaluation of patients with liver lesions. Common benign and malignant liver lesions are presented with radiologic characteristics and treatment options.

Application of preoperative portal vein embolization before major hepatic resection in patients with normal or abnormal liver parenchyma

BACKGROUND

Clinical parameters influencing the effect of preoperative portal vein embolization (PVE) in hypertrophying the nonembolized lobe of patients with either normal or abnormal liver parenchyma and its effect upon portal pressure were examined to identify the patient population for whom this approach is most suited.

METHODS

The study population included 43 patients undergoing major hepatectomy after PVE. Patients were divided into 2 groups according to their liver parenchyma: 17 patients with normal liver parenchyma (N group) and 26 patients with damaged liver parenchyma due to viral hepatitis (D group). We calculated the correlation between volumetric increases in the nonembolized (left) lobe after PVE (hypertrophic ratio = post-PVE left lobe volume/pre-PVE left lobe volume) using computed tomography volumetry before and 2 weeks after PVE. Clinical parameters also were examined to identify those parameters modifying the hypertrophic ratio in each group, and changes in portal pressure by PVE and the subsequent hepatectomy were recorded. Finally, by comparing patients with or without postoperative liver failure after hepatectomy, the influence of the hypertrophic ratio and portal pressure on the outcome of subsequent hepatectomy was examined.

RESULTS

The hypertrophic ratio was 1.34 +/- 0.23 in the N group, and 1.25 +/- 0.21 in the D group. This difference was not significant. Multiple regression analysis revealed that the parenchymal volumetric rate of the right lobe (PVR) in the D group and both PVR and prothrombin time in the N group were independent parameters predicting the hypertrophic ratio. The portal pressure increased immediately after PVE and was similar in both groups to levels after hepatectomy. Six patients in the D group experienced postoperative liver dysfunction. In 5 of these 6 patients, the hypertrophic ratio was below 1.2, and the portal pressure was higher than that in patients without liver dysfunction.

CONCLUSIONS

PVE induces hypertrophy of the nonembolized lobe of both abnormal and normal liver parenchyma, and the effect was predictable. Postoperative liver failure appeared to be more severe in patients having a lower hypertrophic ratio and higher portal pressure in abnormal liver parenchyma, however. PVE also may have diagnostic use in predicting portal pressure after hepatectomy, which may be associated with surgical outcome.

[Portal vein embolization prior to hepatectomy. Techniques, indications and results]

Postoperative liver failure is a severe complication of major hepatectomies, in particular in patients with a chronic underlying liver disease. Preoperative interruption of the portal flow in the liver territories planned to be removed, induces their atrophy and the compensatory hypertrophy of the segments spared by the resection. This interruption can be induced by the surgical ligation of the portal branches or by the percutaneous intraportal injection, under ultrasound guidance, of glues or sclerosing agents. Preoperative portal vein embolisation is usually indicated when the remnant liver accounts for less than 25-40% of the total liver volume. Feasibility is close to 100% and the risk comparable to that of a percutaneous liver biopsy. It is well tolerated and the biological impact is minimal in patients without liver failure. Compensatory hypertrophy of the non-embolised segments is maximal during the first 2 weeks and persists, although to a lesser extent during approximately 6 weeks. The magnitude of hypertrophy is correlated with the volume of parenchyma embolised, and is reduced in diabetic or jaundiced patients or when there is an active chronic liver disease. Liver resection is performed 2 to 6 weeks after embolisation. Retrospective studies and one prospective study suggest that patients so prepared have a reduced perioperative risk and that their long term carcinologic results are not impaired.

Biliary tract cancer

Advances in cellular and molecular biology of extrahepatic cholangiocarcinoma and gallbladder adenocarcinoma are providing innovative means for the diagnosis and treatment of biliary tract cancer. Similarly, refinements in noninvasive studies--including helical computed tomography, magnetic resonance cholangiopancreatography, and endoscopic ultrasonography--are enabling more accurate diagnosis, staging, and treatment planning for these tumors. Complete resection remains the only means for cure, and recent reports from major hepatobiliary centers support aggressive wide resection for bile duct and gallbladder cancer. Palliation of malignant strictures has improved with advanced endoscopic techniques, newer polyurethane-covered stents, endoscopic microwave coagulation therapy, and radiofrequency intraluminal endohyperthermia. The preliminary data on such minimally invasive techniques suggest an improvement in quality of life and survival for selected patients.

Portal vein embolization: rationale, technique and future prospects

BACKGROUND

Advances in surgery have reduced the mortality rate after major liver resection, but complications resulting from inadequate postresection hepatic size and function remain. Portal vein embolization (PVE) was proposed to induce hypertrophy of the anticipated liver remnant in order to reduce such complications. The techniques, measurement methods and indications for this treatment remain controversial.

METHODS

A Medline search was performed to identify papers reporting the use of PVE before hepatic resection. Techniques, complications and results are reviewed.

RESULTS

Complications of PVE typically occur in less than 5 per cent of patients. No specific substance (cyanoacrylate, thrombin, coils or absolute alcohol) emerged as superior. The increase in remnant liver volume averages 12 per cent of the total liver. The morbidity rate of resection after treatment is less than 15 per cent and the mortality rate is 6-7 per cent with cirrhosis and 0-6.5 per cent without cirrhosis. Embolization is currently used for patients with a normal liver when the anticipated liver remnant volume is 25 per cent or less of the total liver volume, and for patients with compromised liver function when the liver remnant volume is 40 per cent or less.

CONCLUSION

This treatment does not increase the risks associated with major liver resection. It may be indicated in selected patients before major resection. Future prospective studies are needed to define more clearly the indications for this evolving technique.