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Purpose: The liver function in outflow-obstructed regions is reportedly impaired; however, the functional decrease has not been quantitatively assessed. We therefore evaluated the uptake of indocyanine green (ICG) into hepatocytes and the mRNA expression associated with the liver function in outflow-obstructed regions using rat models., Methods: A total of 20 rats with the ligation of the right median hepatic vein to induce outflow obstruction were studied. Five rats each were grouped by the time of re-laparotomy, and the fluorescence intensity (FI) values of ICG. The mRNA expression, including that of Albumin, Cytochrome P450 (Cyp) 1a2, Cyp3a1, Cyp7a1, and Gamma-glutamylcysteine synthetase, in outflow-obstructed (mRNA Out-Ob ) and non-outflow-obstructed (mRNA Non ) regions was assessed., Results: Microscopic fluorescence imaging showed that the FI values were significantly lower in outflow-obstructed regions than in non-outflow-obstructed regions at 12 h, 24 h, and 3 days after ligation of the hepatic vein. The mRNA Out-Ob /mRNA Non ratios decreased to approximately 30% at 12 h after the outflow obstruction and increased to approximately 70-80% at 7 days., Conclusions: The liver function in outflow-obstructed regions was impaired in terms of the uptake of ICG and the mRNA expression. Our findings may help estimate the postoperative functional remnant liver volume by considering the decrease in the liver function in outflow-obstructed regions., (© 2022. The Author(s) under exclusive licence to Springer Nature Singapore Pte Ltd.)

Background: Probe electrospray ionization-mass spectrometry (PESI-MS) can rapidly visualize mass spectra of small, surgically obtained tissue samples, and is a promising novel diagnostic tool when combined with machine learning which discriminates malignant spectrum patterns from others. The present study was performed to evaluate the utility of this device for rapid diagnosis of colorectal liver metastasis (CRLM)., Methods: A prospectively planned study using retrospectively obtained tissues was performed. In total, 103 CRLM samples and 80 non-cancer liver tissues cut from surgically extracted specimens were analyzed using PESI-MS. Mass spectra obtained by PESI-MS were classified into cancer or non-cancer groups by using logistic regression, a kind of machine learning. Next, to identify the exact molecules responsible for the difference between CRLM and non-cancerous tissues, we performed liquid chromatography-electrospray ionization-MS (LC-ESI-MS), which visualizes sample molecular composition in more detail., Results: This diagnostic system distinguished CRLM from non-cancer liver parenchyma with an accuracy rate of 99.5%. The area under the receiver operating characteristic curve reached 0.9999. LC-ESI-MS analysis showed higher ion intensities of phosphatidylcholine and phosphatidylethanolamine in CRLM than in non-cancer liver parenchyma (P < 0.01, respectively). The proportion of phospholipids categorized as monounsaturated fatty acids was higher in CRLM (37.2%) than in non-cancer liver parenchyma (10.7%; P < 0.01)., Conclusion: The combination of PESI-MS and machine learning distinguished CRLM from non-cancer tissue with high accuracy. Phospholipids categorized as monounsaturated fatty acids contributed to the difference between CRLM and normal parenchyma and might also be a useful diagnostic biomarker and therapeutic target for CRLM.

Background . Real-time virtual sonography (RVS) is a navigation system for liver surgery. In this study, the degree of misalignment of intraoperative RVS images with computed tomographic (CT) images was measured. Methods . Between December 2014 and July 2015, intraoperative RVS was performed in a total of 33 patients undergoing liver surgery. Reconstructed CT images, rendered like intraoperative ultrasonographic (IOUS) images, were adjusted with the IOUS images and visualized side by side. The degree of misalignment between the reconstructed CT images and IOUS images was measured at anterior section, posterior section, and left liver in each patient. Furthermore, the time required for the adjustment was measured as the "adjustment time." Results . The degree of misalignment between the images could potentially be measured for a total of 96 points in the 33 patients. Of these, the actual measurement could not be conducted for 35 points due to poor visualization of the intrahepatic vasculature (n = 20) or to a large misalignment that hampered continuation of further adjustment (n = 15). The median degree of misalignment was 9.8 mm (range = 2.4-37.6 mm) in the right anterior section, 9.8 mm (range = 2.7-71.5 mm) in the right posterior section, and 9.5 mm (range = 0.9-37.6 mm) in the left liver. The median adjustment time was 105 seconds (range = 51-245 seconds). Conclusions . Although some misalignment occurred, it might be acceptable for selected situations. Further investigation is needed to reduce the frequency of adjustment failure.

Background: Right hemihepatectomy or systematic resection of segment 7 or 8 involves partial resection of the paracaval portion of the caudate lobe. However, the boundary between the caudate lobe and segment 7 or 8 remains unclear. We examined the anatomical territory of the caudate lobe with special reference to the boundary between the paracaval portion and segment 7 or 8 for precise anatomical hepatectomies., Methods: We enrolled 63 consecutive healthy donor candidates for living-donor liver transplantation from 2012 to 2014 in this study. The caudate lobe was defined according to Kumon's subdivision system, and the boundary between the paracaval portion and segment 7 or 8 was investigated based on three-dimensional computed tomography scan images using SYNAPSE VINCENT ® ., Results: The paracaval portion of the liver protruded on the liver surface underneath the right diaphragm on the ventral side of the right hepatic vein (RHV) in 10 participants (16%) and on the dorsal side of the RHV in 9 participants (14%). A branch of the RHV, the "paracaval vein," was found in all 63 participants and ran longitudinally along the right border of the paracaval portion (n = 30, 48%) and within segment 7 (n = 16, 25%) or segment 8 (n = 17, 27%)., Conclusions: The paracaval portion of the liver protruded on the liver surface underneath the right diaphragm in one third of our participants. The paracaval vein can be a landmark for the boundary between the caudate lobe and the segment 7 or 8 in half of the cases.

Living donor liver transplantation using the left liver graft with the middle hepatic vein (MHV) is a well-established procedure. Following such procedures, outflow obstruction occurs in remnant livers. However, the effects of the outflow-obstructed liver volume (LV Out-Ob ), with or without venous communication development, remain unclear. The aim of the study is to investigate effects of outflow-obstructed regions by focusing on short-term outcomes and remnant liver hypertrophy in left liver procurement donors. Of 532 donors, we collected data from 119 undergoing left liver procurement with the MHV. Postoperative hepatic parameters, venous communication development, and liver hypertrophy were evaluated in 2 donor groups based on LV Out-Ob . The left liver was procured with the MHV in 119 donors, who formed 2 more groups based on the median LV Out-Ob : large-outflow-obstruction group (n = 60; LV Out-Ob  ≥ 263 mL) and small-outflow-obstruction (n = 59; LV Out-Ob  < 263 mL) group. Postoperative liver function parameters were significantly impaired in the large-outflow-obstruction group compared with the small-outflow-obstruction group. Postoperative venous communication developed in 52 (66.7%) of 78 donors analyzed. Hypertrophy ratios in remnant right livers and right paramedian sectors were significantly higher in the small-outflow-obstruction group than in the large-outflow-obstruction group (P = 0.01 and P = 0.02, respectively). The liver hypertrophy ratio of outflow-obstructed regions was better, especially in small regions developing venous communication (P =  0.001). The postoperative morbidity rate did not differ significantly (P = 0.66). In conclusion, the procurement of the left liver graft with the MHV was safely performed with minimal morbidity by assessing the donor remnant right liver volume with and without outflow obstruction. Attention should be paid that postoperative hepatic parameters and remnant liver hypertrophy were impaired in the remnant livers with large outflow-obstructed regions compared with those with small outflow-obstructed regions. Liver Transplantation 23 1531-1540 2017 AASLD., (© 2017 by the American Association for the Study of Liver Diseases.)

Background: Inflow and outflow patency of the liver parenchyma is required to maximize the metabolic function of the liver. However, the definition and distribution of hepatic venous drainage regions has yet to be reported. The aim of this study was to define major hepatic venous tributaries and investigate the mean drainage volume of each territory., Methods: Three-dimensional (3D) simulations from the livers of 100 healthy donors were reviewed for living donor liver transplantation to determine the distribution of the significant hepatic venous tributaries and the drainage patterns of each segment., Results: The left hepatic vein (LHV), middle hepatic vein (MHV), and right hepatic vein (RHV) contributed a mean drainage of 20.7%, 32.7%, and 39.6% of the entire liver, respectively. Accessory hepatic veins accounted for remaining 7.0%. The middle right hepatic vein (MRHV) and inferior right hepatic vein (IRHV) accounted for a mean total drainage of 8.0% and 10.6%, respectively, when they present. In addition, major tributaries of hepatic veins were clearly detected, and their typical distributions were described., Conclusions: Knowledge of hepatic venous territories is necessary for complex hepatobiliary surgery. This "venous drainage map" may provide useful information for complex liver surgery and transplantation., (Copyright © 2016 International Hepato-Pancreato-Biliary Association Inc. Published by Elsevier Ltd. All rights reserved.)

Right lateral sector (RLS) grafting has been introduced to enlarge the potential donor pool for living donor liver transplantation (LDLT); however, evidence of its feasibility is limited. Data from 437 LDLTs carried out between 2000 and 2013 were analyzed retrospectively. LDLTs using a right liver graft (n = 251) were compared with those using a RLS graft (RLSG; n = 28). No donor mortality occurred, and the major complication rates were similar between the two groups. Postoperative liver function preservation was better in the RLSG donors. Concerning the recipients, the mortality and overall survival rates were similar between the two groups. The complication rate for the recipients was higher when more than two arterial or biliary anastomoses were necessary. A systematic literature search identified four reports on LDLT using RLSGs. Among 66 LDLTs, including the present series, there were no cases of donor death, and the rates of major and minor complications in the donors were 6% and 29%, respectively. The major complication and overall mortality rates in the recipients were 29% and 6%, respectively. LDLT using an RLSG is feasible, with an acceptable survival rate among the recipients., (© Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Special care must be taken in hepatic vein reconstruction to avoid outflow block in living donor liver transplantation (LDLT) with a right liver graft. We have used cryopreserved homologous veins to reconstruct the right hepatic vein (RHV), middle hepatic vein (MHV), MHV tributaries (V5 and V8), and inferior right hepatic vein (IRHV). The reconstruction of V5, V8, and IRHV was based on the estimated congestive volume, calculated by the computed tomography volumetry, to secure the functional graft volume of 40% of the recipient standard liver volume. Among 262 right liver LDLT recipients, the number of reconstructed RHVs, MHVs, V5s, V8s, and IRHVs was 262, 48, 110, 111, and 147, respectively, and the overall patency was 95%, 100%, 36%, 58%, and 86%, respectively. Although the patency of the RHVs and MHVs was satisfactory, that of the V5s, V8s, and IRHVs was suboptimal. Patency of the IRHVs (86%, 126/147) was significantly better than that of both V5s (36%, 40/110) and V8s (58%, 64/111; P < 0.001). In addition, the estimated volume drained by IRHVs was significantly greater than that of V5s and V8s (IRHV, 176 ± 92 mL; V5, 105 ± 49 mL; V8, 127 ± 60 mL; P < 0.001). The patency of IRHV was significantly improved by applying the double inferior vena cava method (93%, 94/101) when compared to the direct anastomosis to vena cava (68%, 25/37; P < 0.001). The IRHV functioned as a main drainage route in cases of an obstructed RHV. In conclusion, reconstruction of the IRHV is recommended, not only to improve the functional reserve of the graft, but also to secure multiple drainage routes of the graft., (© 2015 American Association for the Study of Liver Diseases.)

Background & Aims: The standard liver volume (SLV) is widely used in liver surgery, especially for living donor liver transplantation (LDLT). All the reported formulas for SLV use body surface area or body weight, which can be influenced strongly by the general condition of the patient., Methods: We analyzed the liver volumes of 180 Japanese donor candidates and 160 Swiss patients with normal livers to develop a new formula. The dataset was randomly divided into two subsets, the test and validation sample, stratified by race. The new formula was validated using 50 LDLT recipients., Results: Without using body weight-related variables, age, thoracic width measured using computed tomography, and race independently predicted the total liver volume (TLV). A new formula: 203.3-(3.61×age)+(58.7×thoracic width)-(463.7×race [1=Asian, 0=Caucasian]), most accurately predicted the TLV in the validation dataset as compared with any other formulas. The graft volume for LDLT was correlated with the postoperative prothrombin time, and the graft volume/SLV ratio calculated using the new formula was significantly better correlated with the postoperative prothrombin time than the graft volume/SLV ratio calculated using the other formulas or the graft volume/body weight ratio., Conclusions: The new formula derived using the age, thoracic width and race predicted both the TLV in the healthy patient group and the SLV in LDLT recipients more accurately than any other previously reported formulas., (Copyright © 2015 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background: Real-time virtual sonography is an innovative imaging technology that detects the spatial position of an ultrasound probe and immediately reconstructs a section of computed tomography (CT) and/or magnetic resonance in accordance with the ultrasound image, thereby allowing a real-time comparison of those modalities. A novel intraoperative navigation system for liver resection using real-time virtual sonography has been devised for the detection of tumors and navigation of the resection plane., Methods: Sixteen patients with hepatic malignancies (26 tumors in total) were involved in this study, and the system was used intraoperatively. The tumor size ranged 2 to 140 mm (23 mm in median). By the navigation system, operators could refer intraoperative ultrasound image displayed on the television monitor side-by-side with corresponding images of CT and/or magnetic resonance. In addition, the system overlaid preoperative simulation on the CT image and highlighted the extent of resection so as to navigate the resection plane. Because the system used electromagnetic power in the operation room, the feasibility and safety of the system was investigated as well as its validity., Results: The system could be used uneventfully in each operation. All of the 26 tumors scheduled to be resected were detected by the navigation system. The weight of the resected specimen correlated with the preoperatively simulated volume (R = 0.995, P < .0001)., Conclusion: The feasibility and safety of the navigation system were confirmed. The system should be helpful for intraoperative tumor detection and navigation of liver resection.

Background/purpose: A discrepancy between the actually obtained graft weight and the preoperative volumetric estimation is often observed in living donor liver transplantation. The aim of the study reported here was to clarify the prevalence and degree of this discrepancy between estimated and actual liver volume., Materials and Methods: Preoperative volumetric evaluations of 26 live donor livers were performed using three-dimensional computed tomography software. The weight of the liver graft and blood contained in the graft were measured immediately after procurement and compared with the preoperative estimate. The graft was also weighed after perfusion and after back-table procedures., Results: Analysis of the results revealed that blood-free graft weight was significantly overestimated (p = 0.02) and blood weight was significantly underestimated (p < 0.001). The sum of the weight of the graft and blood best corresponded to the preoperative volume estimate (R (2) = 0.64, p < 0.001). The back-table procedures significantly decreased the weight of the liver graft (p < 0.001). Graft weight after perfusion and after venous reconstruction corresponded to 95 and 90% of the weight obtained before perfusion, respectively. Multivariate analysis revealed that donor age had the most significant influence on the ratio of the weight decrease in the University of Wisconsin solution (p = 0.03)., Conclusions: The weight of liver grafts decreases significantly during back-table procedures. Underestimation of the blood weight contained in the graft is one cause of the graft weight discrepancy, but weight loss while the graft was immersed in the University of Wisconsin solution was also observed. These phenomena should be taken into account when graft size is being determined.

Background: A left liver graft in living donor liver transplantation often has 2 arterial stumps. The indication for multiple arterial reconstructions remains controversial. The aim of this retrospective study was to investigate whether single anastomosis of a left liver graft affects the outcome of living donor liver transplantation., Methods: When a hepatic graft had 2 arterial stumps, the thicker (dominant) stump was reconstructed first. After the initial reconstruction, another reconstruction was performed only if no pulsating flow was observed from the remnant stump. A total of 134 left liver grafts were divided into 3 groups: Group 1 (n = 70), 1 arterial stump on a graft with 1 arterial reconstruction; Group 2 (n = 59), 2 stumps with 1 arterial reconstruction; Group 3 (n = 5), 2 stumps with 2 arterial reconstructions. The incidence of hepatic arterial thrombosis, biliary stenosis, and patient survival was compared between Groups 1 and 2., Results: The incidence of arterial thrombosis and biliary stenosis, and the patient survival curves, were equivalent between Groups 1 and 2., Conclusion: When the criteria were satisfied, single arterial reconstruction in a left liver graft with 2 arterial stumps did not affect the patient survival or biliary complications., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Background: The relationship among bile duct (BD), portal vein (PV), and/or hepatic artery (HA) anatomy is controversial, but no investigation has previously compared left and right liver graft transplantation in terms of variant vasculobiliary anatomy. Therefore, in this study, we explored whether variant BD anatomy can be predicted from portal PV or HA anatomy, and we compared left and right liver graft transplantation from the standpoint of vasculobiliary reconstruction., Methods: The associations between BD and PV and/or HA anatomies were evaluated in 361 donors. The number of vasculobiliary stumps in each graft, the number of stumps reconstructed, and the clinical outcomes were then compared between 133 left and 154 right liver grafts., Results: Variant BD was more frequently associated with variant than with normal PV anatomy (57.0% vs 28.4%). No correlation was found between variant BD and variant HA anatomy. Multiple PVs (left versus right, 0% vs 5.8%) and BDs (40.6% vs 59.7%) appeared more frequently in right liver grafts, and all stumps were reconstructed. Although multiple HAs appeared more frequently in left liver grafts (47.4% vs 1.3%), multiple stumps were rarely anastomosed. The incidence of HA/PV thrombosis or biliary strictures was comparable between left and right liver grafts., Conclusion: Variant PV, but not variant HA, anatomies frequently accompany variant BD anatomy. Vasculobiliary variations sometimes lead to technical complexities, but this is more problematic in right liver graft transplantation. Left liver grafts are more feasible for vasculo-biliary reconstruction., (Copyright (c) 2010 Mosby, Inc. All rights reserved.)

Hepatic artery and portal vein thrombosis are devastating complications of partial liver transplantation. Early detection of inflow complications is important, as re-reconstruction can salvage the graft. Near-infrared spectroscopy or laser Doppler flowmetry can be used to detect tissue oxygenation or microcirculation on the liver surface. The aim of this study was to examine which of these two methods better detects changes in hepatic inflow. Sangen-strain pigs (n = 5) were used. The tips of the near-infrared spectroscopy and laser Doppler flowmetry probes were placed separately on the surface of the right liver. Inflow to the liver was controlled during the following seven conditions: control (not clamped), half- and totally clamped portal vein, half- and totally clamped hepatic artery, and half- and totally clamped portal vein and artery. Tissue blood flow was calculated using laser Doppler flowmetry. Oxyhemoglobin, deoxyhemoglobin, and the tissue oxygenation index were measured and calculated using a near-infrared spectroscopy system. The tissue blood flow and oxygenation index could not be used to differentiate between the half-clamped portal vein, half-clamped hepatic artery, and totally clamped portal vein conditions. The oxyhemoglobin minus deoxyhemoglobin value was significantly decreased after half or total clamping of the portal vein or hepatic artery (p <. 001 for each condition). The findings of the present study indicate that near-infrared spectroscopy was more sensitive than Doppler flowmetry for detecting changes in hepatic tissue inflow from the liver surface.

Objective: Recurrence of hepatitis and progression of fibrosis are major problems in liver transplantation (LT) for patients with hepatitis C. Liver stiffness measurement (LSM) by transient elastography correlates well with histologic liver fibrosis stages in chronic liver diseases. The aim of this study was to evaluate the usefulness of transient elastography for the assessment of fibrosis in patients after living donor LT., Material and Methods: Seventy-nine patients who visited our institution, and in whom LSM was successfully evaluated, were enrolled in the study. The patients were divided into three groups according to positivity for hepatitis C antibody and hepatitis B surface antigen as the hepatitis C virus (HCV) group (n=37), the hepatitis B virus (HBV) group (n=10), and the NBNC (negative for both hepatitis B and C) group (n=32). The correlation between LSM and histologic fibrosis stage was assessed in 36 patients. LSM was also compared with regard to the effect of interferon therapy in HCV patients., Results: The median value for liver stiffness was 6.8 kPa and the median time from LT was 3.1 years. In patients who underwent liver biopsy, stiffness was significantly correlated with the stages of fibrosis (p<0.001, rho = 0.848). In patients who received interferon therapy after LT, the LSM decreased over time in those with a sustained virological response, whereas LSM increased in patients without a response., Conclusion: Transient elastography may be an appropriate non-invasive procedure to sequentially assess the progression of liver fibrosis in patients after LT.

Background/aims: Reversed portal flow following liver transplantation is life-threatening complication. There are few reports, however, regarding reversed portal flow after liver transplantation., Methodology: We performed 180 living donor liver transplantations (LDLTs) over 8 years. Portal vein flow was routinely measured postoperatively two or three times a day during the first 2 weeks after LDLT. Surgical correction of reversed portal flow was attempted as soon as possible., Results: Five patients (2%) were complicated by postoperative hepatofugal portal flow. The reversed portal flow was corrected surgically in all the patients by splenectomy and/or ligation of the residual collateral veins. The revision operation was repeated in two patients. In three patients, the shunts responsible for hepatofugal flow were not detected in preoperative imaging, which must be approached under the guidance of intraoperative ultrasound or radiologic examination. All five patients survived the operation., Conclusions: Hepatofugal flow causes ischemic damage to the graft, which will not normalize spontaneously. Prompt treatment of the reversed portal flow salvaged the graft.

Background: An accurate estimation of preoperative volumetric measurements of the donor liver is essential in living donor liver transplantation., Methods: Three-dimensional (3-D) computed tomography (CT) was applied to 56 living donors. 3-D images of the liver were constructed using the region-growing method and the volume of each sector was measured., Results: The median volume ratios of the left liver, caudate lobe, right paramedian, and lateral sectors were 34%, 4%, 38%, and 25% of the total liver volume, respectively. The shape of the congestive area in the right paramedian sector was properly demonstrated by 3-D CT. The volume of the region corresponded to 32% of the right liver. The actual volume of the graft correlated well with the estimated graft volume (n = .86)., Conclusions: The region-growing method was useful for graft selection and for determining the indication of middle hepatic vein reconstruction in right liver grafts.

The right lateral sector is an alternative graft for living donor liver transplantation. Three-dimensional image reconstruction of right lateral sector grafts was performed to reveal vascular anatomy and volume using three-dimensional computed tomography software in three donors. There was a correlation between actual and estimated volume (r=.93), although actual graft volume tended to be larger than the preoperative estimated volume. In one donor, a portal branch of the right lateral sector was independently ramified. The branch was sacrificed in the operation because its territory volume was only 44 cm3. Three-dimensional images matched the shape of the right lateral sector graft. Three-dimensional computed tomography might be useful before donor hepatectomy, providing important information for decisions regarding the operative procedure.

Background/aims: Complete outflow is impossible to maintain on both sides in donors undergoing hemi-liver graft harvesting, because the middle hepatic vein (MHV) can be preserved on only one side. The area in which outflow veins are disrupted becomes congested, and does not sufficiently regenerate., Methodology: The subjects of the study were 55 living donors who provided the left liver with caudate lobe, including the MHV. The midpoint between the tributaries of the MHV and the right hepatic vein was determined preoperatively with computed tomography. The midpoint between the tributaries of the MHV and right hepatic vein and the borderline between the right and left liver were used to predict the MHV drainage area volume. Total bilirubin levels, the prothrombin time international normalization ratio, and alanine aminotransferase were measured in donors on postoperative days 1, 3, 5 and 7., Results: The parameters that correlated with the MHV drainage area volume included total bilirubin on days 5 and 7, prothrombin time international normalization ratio on day 3, and alanine aminotransferase on day 7., Conclusions: Middle hepatic vein drainage area volume, calculated using the present method, correlated with early liver function after left liver harvesting with the MHV.

The objectives of this study were to determine the time course of copper (Cu) absorption in the Bedlington Terrier (BT) dog after duodenal infusion of Cu and to determine the onset of Cu accumulation in BT puppies. At 80 minutes after infusion, Cu was present in the bile and liver at 26.1 and 2675 microg/g dry weight (dw), as compared with 598 and 224 microg/g dw, respectively, in the control. In the puppies, the mean liver Cu concentrations were 443 +/- 216 microng/g dw as compared with 54 +/- 34 microg/g dw in their controls. The BT puppies had large numbers of Cu granules in their hepatic lysosomes, with very few in the bile canaliculi. In contrast, the controls had few granules in their lysosomes and large numbers in their canaliculi. These results suggest that hepatic Cu accumulation occurs rapidly and in utero in the BT.

Right-lobe graft has been used most frequently for living donor liver transplantation in adult patients; however, some donors cannot donate their right lobe (according to the Healey and Scroy's terminology) because the remaining residual liver would be too small. A recent study suggested the possibility of right posterior segment graft in these donors. The purpose of this study was to evaluate the feasibility of right lobe or right posterior segment graft with a volumetric analysis. Liver volumetry by computed tomography was performed in 155 consecutive donors, and the volume of each liver segment was calculated. To confirm the reliability of volumetric examination, the estimated graft volume and the actual weight were compared. The average volume ratios of the left lateral segment, left medial segment, caudate lobe, right anterior segment, and right posterior segment were 17%, 14%, 2%, 37%, and 30%, respectively. In 39 donors (25%), the volume ratio of the right lobe was over 70%. Of these donors, 72% had a larger (difference in volume ratio greater than 5%) right posterior segment than left lobe with caudate lobe. The relationship between the estimated volume and actual weight was linear. The present results suggest that right lobectomy carries a potential risk and that the right posterior segment may be useful as an alternative graft from the point of donor's safety.

The optimal doses of tacrolimus (FK) needed to reach and maintain a target blood level vary among cases of living donor liver transplantation (LDLT). One hundred and twenty four LDLTs in 122 patients were included in this study. Tacrolimus was administered by continuous intravenous infusion at a rate of 2.5 microg/kg/h just after the operation. The time needed to reach the target blood level and the dose needed to maintain this level for 1 week (17-18 ng/mL) were defined as the initial duration (ID) and secondary dose (SD), respectively. In the first 100 LDLTs, the correlations between ID or SD and some clinical factors were examined and equations for predicting ID or SD were derived. In the latest 24 LDLTs, FK was administered using these equations and the actual and calculated ID and SD values were compared. A multiple regression analysis revealed that only the graft weight/recipient standard liver volume (GW/SLV) ratio (%) correlated with ID or SD. Stepwise regression analysis led to the equations ID (h) = 0.4 x GW/SLV ratio + 0.2; SD (microg/kg/h) = 0.02 x GW/SLV ratio - 0.4. Simple regression analysis revealed a significant correlation between the actual and calculated ID and SD values (p < 0.0001). Initial duration and SD can be estimated from equations using the GW/SLV ratio.

Total serum bile acid assay for the evaluation of liver function has been available for many years but its application has been limited primarily by factors such as methodology, equipment and cost. New and improved methods for bile acid assay such as the radioimmunoassay or the hydroxysteroid dehydrogenase techniques have brought the assay for bile acids into the realm of the clinical laboratory. The efficacy of bile acids for clinical diagnostic use in the evaluation of liver function has not been firmly established. Newer methods using high pressure liquid chromatography to develop a profile of the different bile acids may clarify its usefulness and define its role among the many available tests of liver function in animals.