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

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.