Accuracy of an age-adjusted formula in assessing the graft volume in living donor liver transplantation

CT volume analysis in living donor liver transplantation: accuracy of three different approaches

OBJECTIVES

The aim of this retrospective study is to compare and evaluate accuracy of three different approaches of liver volume quantification in living donor transplantations.

METHODS

This is a single-center, retrospective study of 60 donors. The total and right lobe liver volumes were analyzed in the portal-venous phase by two independent radiologists who estimated the volumes using manual, semi-automated and automated segmentation methods. The measured right lobe liver volume was compared to the real weight of the graft after back-table examinations.

RESULTS

The mean estimated overall liver volume was 1164.4 ± 137.0 mL for manual, 1277.4 ± 190.4 mL for semi-automated and 1240.1 ± 108.5 mL for automated segmentation. The mean estimated right lobe volume was 762.0 ± 122.4 mL for manual, 792.9 ± 139.9 mL for semi-automated and 765.4 ± 132.7 mL for automated segmentation. The mean graft weight was 711.2 ± 142.9 g. The manual method better correlated with the graft weight (r = 0.730) in comparison with the semi-automated (r = 0.685) and the automated (r = 0.699) methods (p < 0.001). The mean error ratio in volume estimation by each application was 12.7 ± 16.6% for manual, 17.1 ± 17.3% for semi-automated, 14.7 ± 16.8% for automated methods. There was a statistically significant difference between the mean error ratio of the manual and the semi-automated segmentations (p = 0.017), and no statistically significant difference between the manual and the automated applications (p = 0.199).

CONCLUSION

Volume analysis application better correlates with graft weight, but there is no obvious difference between correlation coefficients of all three methods. All three modalities had an error ratio, of which the semi-automated method showed the highest value.

CRITICAL RELEVANCE STATEMENT

Volume analysis application was more accurate, but there is no drastic difference between correlation coefficients of all three methods.

Left lateral segment liver volume is not correlated with anthropometric measures

BACKGROUND

Liver transplantation is definitive therapy for end stage liver disease in pediatric patients. Living donor liver transplantation (LDLT) with the left lateral segment (LLS) is often a feasible option. However, the size of LLS is an important factor in donor suitability - particularly when the recipient weighs less than 10 kg. In the present study, we sought to define a formula for estimating left lateral segment volume (LLSV) in potential LLS donors.

METHODS

We obtained demographic and anthropometric measurements on 50 patients with Computed Tomography (CT) scans to determine whole liver volume (WLV), right liver volume (RLV), and LLSV. We performed univariable and multivariable linear regression with backwards stepwise variable selection (p < 0.10) to determine final models.

RESULTS

Our study found that previously reported anthropometric and demographics variables correlated with volume were significantly associated with WLV and RLV. On univariable analysis, no demographic or anthropometric measures were correlated with LLSV. On multivariable analysis, LLSV was poorly predicted by the final model (R2 = 0.10, Coefficient of Variation [CV] = 42.2) relative to WLV (R2 = 0.33, CV = 18.8) and RLV (R2 = 0.41, CV = 15.8).

CONCLUSION

Potential LLS living donors should not be excluded based on anthropometric data: all potential donors should be evaluated regardless of their size.

The authors' reply: Indispensable discrepancy between predicted graft "volume" and actual graft "weight" in clinical practice in living-donor liver transplantation

We would like to respond to the Letter to the Editor "'GRWR' or 'GV/SLV' in clinical practice in living donor liver transplantation" by Haruki et al, that is a comment on our original article "Which is better to use 'body weight' or 'standard liver weight,' for predicting small-for-size graft syndrome after living-donor liver transplantation?" in Annals of Gastroenterological Surgery.

Small-for-size graft, small-for-size syndrome and inflow modulation in living donor liver transplantation

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

Three-Dimensional Volumetric Assessment of Graft Volume in Living Donor Liver Transplantation: Does It Minimise Errors of Estimation?

BACKGROUND

Accurate volumetric assessment of graft and remnant liver is essential in living donor liver transplantation (LDLT) for optimal clinical outcome in both donors and recipients. Recently, three-dimensional (3D) volumetry is proposed over conventional computed tomography (CT) volumetry to minimise errors. The aim of this study is to assess the correlation of estimated graft volume (EGV) by both the methods with actual graft weight (AGW).

METHODS

One hundred fifty-four consecutive donors were enrolled prospectively. Conventional CT volumetry (semiautomatic) and 3D volumetry were performed using Myrian software. Total liver volume (TLV), EGV, and remnant liver volume (RLV) were assessed using both methods and correlated with intraoperatively measured AGW as the reference standard. Error of estimation was calculated accordingly.

RESULTS

One hundred eighteen donors underwent right hepatectomy excluding middle hepatic vein (MHV), twenty-nine donors had left hepatectomy including MHV and six donors underwent left lateral sectionectomy. The median EGV on CT and 3D volumetry was 628.5 ml (140-1300) and 634.5 ml (156-1349), respectively. The median AGW was 647 gm (200-1004). Both CT and 3D volumetry showed strong correlation with AGW (correlation coefficients: 0.834 and 0.856, respectively). Linear correlation is as follows: (a) AGW = 99.75 + 0.818 × EGV (CT) and (b) AGW = 96.03 + 0.835 × EGV (3D). The mean percentage error for CT and 3D volumetry was 14.2 ± 12.5% and 12.2 ± 11.8%, respectively. The overall accuracy of estimation of EGV improved using 3D software (P=0.015). For the subgroup of types of graft, the difference did not reach statistical significance (P=0.062, 0.214 and 0.463 for right, left and left lateral grafts, respectively).

CONCLUSION

Both conventional CT and 3D volumetric methods strongly correlate with AGW in donors of LDLT, whereas overall accuracy of estimation of graft weight improved marginally by 3D volumetry.

Conceptual changes in small-for-size graft and small-for-size syndrome in living donor liver transplantation

Early series in living donor liver transplantation (LDLT) in adults demonstrated a lower safe limit of graft volume standard liver volume ratio 25%–45%. A subsequent worldwide large LDLT series proposed a 0.8 graft recipient weight ratio (GRWR) to define small-for-size graft (SFSG) in adult LDLT. Thereafter, researchers identified innate and inevitable factors including changes in liver volume during imaging studies and graft shrinkage due to perfusion solution. Although the definition of small-for-size syndrome (SFSS) advocated in the 2000s was mainly based on prolonged cholestasis and ascites output, the term SFSS was inadequate to describe clinical manifestations possibly caused by multiple factors. Thus, the term “early allograft dysfunction (EAD),” characterized by total bilirubin >10 mg/dL or coagulopathy with international normalized ratio >1.6 on day 7, has become prevalent to describe graft dysfunction including SFSS after LDLT. Although various efforts have been made to overcome EAD in LDLT, graft selection to maintain an expected GRWR >0.8 and full venous drainage, as well as inflow modulation using splenic artery ligation, have become standard in recent LDLT.

PREOPERATIVE COMPUTED TOMOGRAPHY VOLUMETRY AND GRAFT WEIGHT ESTIMATION IN ADULT LIVING DONOR LIVER TRANSPLANTATION

Background:

Computed tomography volumetry (CTV) is a useful tool for predicting graft weights (GW) for living donor liver transplantation (LDLT). Few studies have examined the correlation between CTV and GW in normal liver parenchyma.

Aim:

To analyze the correlation between CTV and GW in an adult LDLT population and provide a systematic review of the existing mathematical models to calculate partial liver graft weight.

Methods:

Between January 2009 and January 2013, 28 consecutive donors undergoing right hepatectomy for LDLT were retrospectively reviewed. All grafts were perfused with HTK solution. Estimated graft volume was estimated by CTV and these values were compared to the actual graft weight, which was measured after liver harvesting and perfusion.

Results:

Median actual GW was 782.5 g, averaged 791.43±136 g and ranged from 520-1185 g. Median estimated graft volume was 927.5 ml, averaged 944.86±200.74 ml and ranged from 600-1477 ml. Linear regression of estimated graft volume and actual GW was significantly linear (GW=0.82 estimated graft volume, r²=0.98, slope=0.47, standard deviation of 0.024 and p<0.0001). Spearman Linear correlation was 0.65 with 95% CI of 0.45 - 0.99 (p<0.0001).

Conclusion:

The one-to-one rule did not applied in patients with normal liver parenchyma. A better estimation of graft weight could be reached by multiplying estimated graft volume by 0.82.

A new formula for estimation of standard liver volume using computed tomography-measured body thickness

The objective of this article is to derive a more accurate and easy-to-use formula for finding estimated standard liver volume (ESLV) using novel computed tomography (CT) measurement parameters. New formulas for ESLV have been emerging that aim to improve the accuracy of estimation. However, many of these formulas contain body surface area measurements and logarithms in the equations that lead to a more complicated calculation. In addition, substantial errors in ESLV using these old formulas have been shown. An improved version of the formula for ESLV is needed. This is a retrospective cohort of consecutive living donor liver transplantations from 2005 to 2016. Donors were randomly assigned to either the formula derivation or validation groups. Total liver volume (TLV) measured by CT was used as the reference for a linear regression analysis against various patient factors. The derived formula was compared with the existing formulas. There were 722 patients (197 from the derivation group, 164 from the validation group, and 361 from the recipient group) involved in the study. The donor's body weight (odds ratio [OR], 10.42; 95% confidence interval [CI], 7.25-13.60; P < 0.01) and body thickness (OR, 2.00; 95% CI, 0.36-3.65; P = 0.02) were found to be independent factors for the TLV calculation. A formula for TLV (cm³ ) was derived: 2 × thickness (mm) + 10 × weight (kg) + 190 with R² 0.48, which was the highest when compared with the 4 other most often cited formulas. This formula remained superior to other published formulas in the validation set analysis (R² , 5.37; interclass correlation coefficient, 0.74). Graft weight/ESLV values calculated by the new formula were shown to have the highest correlation with delayed graft function (C-statistic, 0.79; 95% CI, 0.69-0.90; P < 0.01). The new formula (2 × thickness + 10 × weight + 190) represents the first study proposing the use of CT-measured body thickness which is novel, easy to use, and the most accurate for ESLV. Liver Transplantation 23 1113-1122 2017 AASLD.

The correlation between preoperative volumetry and real graft weight: comparison of two volumetry programs

Purpose

Liver volumetry is a vital component in living donor liver transplantation to determine an adequate graft volume that meets the metabolic demands of the recipient and at the same time ensures donor safety. Most institutions use preoperative contrast-enhanced CT image-based software programs to estimate graft volume. The objective of this study was to evaluate the accuracy of 2 liver volumetry programs (Rapidia vs. Dr. Liver) in preoperative right liver graft estimation compared with real graft weight.

Methods

Data from 215 consecutive right lobe living donors between October 2013 and August 2015 were retrospectively reviewed. One hundred seven patients were enrolled in Rapidia group and 108 patients were included in the Dr. Liver group. Estimated graft volumes generated by both software programs were compared with real graft weight measured during surgery, and further classified into minimal difference (≤15%) and big difference (>15%). Correlation coefficients and degree of difference were determined. Linear regressions were calculated and results depicted as scatterplots.

Results

Minimal difference was observed in 69.4% of cases from Dr. Liver group and big difference was seen in 44.9% of cases from Rapidia group (P = 0.035). Linear regression analysis showed positive correlation in both groups (P < 0.01). However, the correlation coefficient was better for the Dr. Liver group (R² = 0.719), than for the Rapidia group (R² = 0.688).

Conclusion

Dr. Liver can accurately predict right liver graft size better and faster than Rapidia, and can facilitate preoperative planning in living donor liver transplantation.

Modified Hepatic Venous Plane: A Key Factor for Improving Preoperative MDCT Donor Volume Prediction in Living-Donor Liver Transplantation

OBJECTIVE

The aim of this work was to present our experience using a modified hepatic venous plane in multidetector computerized tomography (MDCT) for reducing the discrepancy between preoperative liver volume estimation and intraoperative weight (IOW) measurement in living-donor liver transplantation (LDLT).

METHODS

We retrospectively reviewed the medical records of 57 consecutive living donors with the use of MDCT as a modality for volumetric assessment for LDLT from May 2007 to January 2015. We divided living donors into 2 groups according to surgical methods: right hepatectomy (RH) and left hepatectomy (LH). Initial liver volumetric measurement (group I) was assessed. After discussions with radiologist, the transplantation surgeon used a modified hepatic venous plane for surgical significant middle hepatic venous variants (>5 mm) in 16 living donors and applied the initial surgical plane in the remaining for the modified donor liver volumetric measurement (group II). We then compared the correlations of these 2 groups with the use of IOW.

RESULTS

The overall correlation (r) between group I and IOW was 0.947. The correlations (r) between group I and IOW were 0.872 and 0.955 for RH and LH, respectively. Compared with group I, group II showed better correlation with IOW: r = 0.949 and 0.981 for RH and LH, respectively. The overall correlation (r) between group II and IOW was 0.980, and the error ratio was 5.95 ± 5.05%.

CONCLUSIONS

Our study showed that using a modified hepatic venous plane in preoperative MDCT, after good communication between transplant surgeon and radiologist, can provide more accurate liver volume estimation and achieve a better correlation with IOW in LDLT.

Assessment of Graft Selection Criteria in Living-Donor Liver Transplantation: The Jikei Experience

In living-donor liver transplantation, graft selection is especially important for the safety of the live donor and an acceptable outcome for the recipient. The essential medical requirements for living liver donation at Jikei University Hospital are as follows: an adult aged 65 years or younger, in good general condition, with partial liver volume of more than 35% of the standard liver volume (SLV) for the recipient, and without severe liver steatosis. Based on our criteria, we performed 13 living-donor liver transplantations between 2007 and 2013, including 1 retransplantation. Three cases were outside our standard donor criteria, including age (18 and 66 years) and 33% graft volume (GV) to SLV ratio for the recipient on preoperative volumetry using computed tomography. In 2 cases, the actual GV to SLV ratio at transplantation was less than 35%. Median postoperative hospital stay was 11 days for the donors, and 29 days for the recipients. All donors returned to their preoperative status, and all recipients were discharged in good condition. Our medical requirements for living liver donation seem to be acceptable because of the good outcome.

The role of adult living donor liver transplantation and recent advances

Twenty years since the first cases were described, adult living donor liver transplantation (ALDLT) is now considered a valid option to expand the donor pool in view of the ongoing shortage of organs and the high waiting list mortality rate. Despite the rapid evolution and acceptance of this complex process of donation and transplantation in clinical practice, the indications, outcome, ethical considerations and quality and safety aspects continue to evolve based on new data from large cohort studies. This article reviews the surgical and clinical advances in the field of liver transplantation, focusing on technical refinements and discussing the issues that may lead to a further expansion of this complex surgical procedure and the role of ALDLT.

Human early liver regeneration after hepatectomy in patients with hepatocellular carcinoma: special reference to age

BACKGROUND AND AIMS

This study was conducted to clarify the effects of age on human liver regeneration.

PATIENTS AND METHODS

Thirty major hepatectomies, equal to or more than two segmentectomies for hepatocellular carcinoma, were performed. Ages ranged from 37 to 85 years and five octogenarians were included. The early regenerative index was defined: (liver volume after 7 days after hepatectomy - estimated remnant liver volume before hepatectomy)/estimated remnant liver volume, using three-dimensional computed tomographic volumetry. Farnesoid X receptor and forkhead box m1 expression in the liver, which has been reported to age-related decrease of liver regeneration in animal model, were examined using real-time polymerase chain reaction. The patients were divided into two groups: low early regenerative index (n = 15), early regenerative index less than 55% and high early regenerative index (n = 15), early regenerative index equal to or more than 55%.

RESULTS

The mean early regenerative index was 57%. Age (R (2) = 0.274, P = 0.003) and estimated blood loss (R (2) = 0.134, P = 0.0466) were inversely correlated with the early regenerative index, and the expression of farnesoid X receptor and forkhead box m1 was not. The incidence of post-hepatectomy liver failure in the low early regenerative index group was higher than that in the high early regenerative index group (P = 0.0421).

CONCLUSIONS

Age and intraoperative blood loss are inversely correlated with early liver regeneration in humans. In elderly patients, massive blood loss should be avoided in view of liver regeneration.

CT volumetry of the liver: where does it stand in clinical practice?

Imaging-based volumetry has been increasingly utilised in current clinical practice to obtain accurate measurements of the liver volume. This is particularly useful prior to major hepatic resection and living donor liver transplantation where the size of the remnant liver and liver graft, respectively, affects procedural success and postoperative mortality and morbidity. The use of imaging-based volumetry, with emphasis on computed tomography, will be reviewed. We will explore the various technical factors that contribute to accurate volumetric measurements, and demonstrate how the accuracies of these techniques are influenced by their methodologies. The strengths and limitations of using anatomical imaging to estimate liver volume will be discussed, in relation to laboratory and functional imaging methods of assessment.

Liver volumetry: Is imaging reliable? Personal experience and review of the literature

The amount of the future liver remnant volume is fundamental for hepato-biliary surgery, representing an important potential risk-factor for the development of post-hepatectomy liver failure. Despite this, there is no uniform consensus about the amount of hepatic parenchyma that can be safely resected, nor about the modality that should be chosen for this evaluation. The pre-operative evaluation of hepatic volume, along with a precise identification of vascular and biliar anatomy and variants, are therefore necessary to reduce surgical complications, especially for extensive resections. Some studies have tried to validate imaging methods [ultrasound, computed tomography (CT), magnetic resonance imaging] for the assessment of liver volume, but there is no clear evidence about the most accurate method for this evaluation. Furthermore, this volumetric evaluation seems to have a certain degree of error, tending to overestimate the actual hepatic volume, therefore some conversion factors, which should give a more reliable evaluation of liver volume, have been proposed. It is widespread among non-radiologists the use of independent software for an off-site volumetric analysis, performed on digital imaging and communications in medicine images with their own personal computer, but very few studies have provided a validation of these methods. Moreover, while the pre-transplantation volumetric assessment is fundamental, it remains unclear whether it should be routinely performed in all patients undergoing liver resection. In this editorial the role of imaging in the estimation of liver volume is discussed, providing a review of the most recent literature and a brief personal series of correlations between liver volumes and resection specimens’ weight, in order to assess the precision of the volumetric CT evaluation.

Revisiting the safety of living liver donors by reassessing 441 donor hepatectomies: is a larger hepatectomy complication-prone?

Donor safety is of paramount importance in performing living donor liver transplantation (LDLT). We retrospectively reviewed donor medical records to confirm whether larger donor hepatectomy is absolutely complication-prone. A total of 441 living donor hepatectomies were performed between October 1996 and July 2012 in our institute, which were divided into three eras (Era I, October 1996 to March 2004; Era II, April 2004 to March 2008; Era III, April 2008 to July 2012) and the incidences of postoperative complications were compared among the three types of hepatectomy-right hepatectomy (RH), left hepatectomy (LH) and left lateral segmentectomy (LLS). Although severe complications (Clavien's grade 3 or more) frequently occurred in RH in Eras I and II (15.4% and 10.7%, respectively), the incidence in Era III decreased to the comparable level observed in LH and LLS (5.4% in RH, 2.3% in LH and 5.3% in LLS). The incidence of postoperative complications did not relate to the type of hepatectomy selected in the latest era. Since most complications after hepatectomy were considered preventable, step-by-step meticulous surgical procedures are a prerequisite for further assuring donor safety irrespective of the type of hepatectomy selected.

Three-dimensional computed tomography analysis of variations in the middle hepatic vein tributaries: proposed new classification

PURPOSE

To evaluate the anatomical variations in the middle hepatic vein tributaries (V5/V8) for determining the reconstruction strategy in right lobe living donor liver transplantation (LDLT).

METHODS

The V5/V8 variations were examined in 268 patients and were classified into three and two types, respectively. The reconstruction rate (RR), patency rate (PR) and clinical outcomes were retrospectively evaluated in 46 right lobe LDLT cases.

RESULTS

In terms of V5 variations, the RR and PR were significantly higher for type 2 than type 3 (82.6 vs. 44.4 % and 73.7 vs. 25.0 %, respectively). The alanine aminotransferase level on postoperative day (POD) 5 in the V5 patent group was significantly lower than in the occluded group (123 vs. 191 IU/dL). Regarding V8 variations, the RR and PR were significantly higher for type 1 than type 2 (44.4 vs. 17.6 % and 75.0 vs. 33.3 %, respectively). The aspartate aminotransferase level on POD 3 was significantly lower in the V8 patent group than in the occluded group (50 vs. 121 IU/dL).

CONCLUSION

For right lobe grafts with single large V5 (type 2) or V8 (type 1) variations, reconstruction is necessary. Our new classification of the MHV tributaries is useful for determining the reconstruction strategy to use in right lobe LDLT.

The causes, risk factors, and outcomes of early relaparotomy after living-donor liver transplantation

BACKGROUND

Although early relaparotomy of the recipient after living-donor liver transplantation (LDLT) is a significant event, its causes, risk factors, and outcomes are still unclear.

METHODS

A retrospective analysis of 284 cases of adult-to-adult LDLT was performed.

RESULTS

The incidence of early relaparotomy of the recipient was 9.2% (n=26). The reasons for relaparotomy were divided into three groups: postoperative bleeding (n=11, 42.3%), insufficient portal venous flow (n=5, 19.2%), and other (n=10, 38.5%). The 6-month graft survival rates of patients in the early laparotomy and nonlaparotomy groups were 61.5% and 88.4%, respectively (P<0.0001). Patients with postoperative bleeding experienced a significantly higher mortality rate (54.6%) than those with other reasons for early relaparotomy (13.3%; P=0.0231). Multivariate analysis showed that a model for end-stage liver disease score of greater than 20 (odds ratio [OR], 9.06; P=0.0434) and an operative blood loss of greater than 15 L (OR, 9.06; P=0.0434) were significant risk factors for graft loss after early relaparotomy. In patients with patent major shunt vessels (>1 cm in diameter, n=31), portal venous flow of less than 1.0 L/min at the end of surgery was a significant risk factor for early relaparotomy to ligate the remaining shunt vessels (OR, 50.5; P=0.0188).

CONCLUSIONS

Early relaparotomy of the recipient is significantly associated with poor graft survival after LDLT. Massive intraoperative blood loss and high model for end-stage liver disease score were associated with poor graft survival in the relaparotomy group.

Strategies for successful left-lobe living donor liver transplantation in 250 consecutive adult cases in a single center

BACKGROUND

Living donor liver transplantation (LDLT) using left-lobe grafts was not generally recognized as feasible due to the problem of graft size.

STUDY DESIGN

We retrospectively evaluated strategies for successful left-lobe LDLT in 250 consecutive cases stratified into 2 eras: Era 1 (n = 121), in which surgical procedures were continually refined, and Era 2 (n = 129), in which established procedures were used.

RESULTS

Graft volume (GV) did not affect the incidence of graft function or survival. Era 2 patients had decreased portal vein (PV) pressure at closure (16.0 ± 3.5 mmHg vs 19.1 ± 4.6 mmHg, p < 0.01), increased PV flow/GV (301 ± 125 mL/min/100g vs 391 ± 142 mL/min/100g, p < 0.01), and improved graft survival rate (1-year: 90.6% vs 81.8%. p < 0.01) despite the smaller GV/standard volume (SLV) ratio (36.2% ± 5.2% vs 41.2% ± 8.8%, p < 0.01) compared with Era 1. Patients in Era 2 had lower PV pressure and greater PV flow (y = 598-5.7 x, p = 0.02) at any GV/SLV compared with cases in Era 1 (y = 480-4.3 x, p < 0.01), representing greater graft compliance. Univariate analysis for graft survival showed that Era 1, Model for End-Stage Liver Disease (MELD) score ≥ 20, inpatient status, closing portal venous pressure ≥ 20 mmHg, no splenectomy, and operative blood loss ≥ 10 L were the risk factors for graft loss, and multivariate analysis showed that Era 1 was the only significant factor (p < 0.01). During Era 2, development of primary graft dysfunction was associated with inpatient recipient status (p = 0.02) and donor age ≥ 45 years (p < 0.01).

CONCLUSIONS

The outcomes of left-lobe LDLT were improved by accumulated experience and technical developments.

Adult to adult living related liver transplantation: Where do we currently stand?

Adult to adult living donor liver transplantation (AALDLT) was first preformed in the United States in 1997. The procedure was rapidly integrated into clinical practice, but in 2002, possibly due to the first widely publicized donor death, the number of living liver donors plummeted. The number of donors has since reached a steady plateau far below its initial peak. In this review we evaluate the current climate of AALDLT. Specifically, we focus on several issues key to the success of AALDLT: determining the optimal indications for AALDLT, balancing graft size and donor safety, assuring adequate outflow, minimizing biliary complications, and maintaining ethical practices. We conclude by offering suggestions for the future of AALDLT in United States transplantation centers.

Assessment of delayed gastric emptying after major hepatectomy using a 13C-acetic acid breath test

PURPOSES

Delayed gastric emptying (DGE) after hepatectomy affects the quality of life of patients, although the causes and related conditions have not been investigated. This study evaluated the relationship between hepatectomy and DGE by the objective assessment of gastric emptying (GE).

METHODS

Nineteen patients who underwent major hepatectomy were prospectively enrolled in the study. Their GE was studied using the (13)C-acetic acid breath test before and after hepatectomy. The results of the GE analysis were correlated with the postoperative course after hepatectomy.

RESULTS

Clinically evident DGE, which was defined as the inability to take in an appropriate amount of solid food orally by postoperative day 14, was not found in these patients, but the gastric half-emptying times before and after hepatectomy were 20.2 ± 9.7 and 28.6 ± 12.2 min, respectively (P = 0.01). The GE time was significantly delayed in patients aged ≥ 41 years, or who underwent right hemihepatectomy.

CONCLUSIONS

Gastric emptying was significantly inhibited in patients who underwent major hepatectomy, and aging and a right-sided hemihepatectomy may be related to the development of DGE.

Hepatic height on coronal computed tomography images predicts total liver volume in European adults without liver disease

BACKGROUND

Hepatic volume measurement provides useful information in a large range of clinical situations.

AIMS

The goal of this study was to test the hypothesis that significant correlation exists between hepatic volume calculated using three-dimensional reconstruction of computed tomography (CT) data and hepatic height calculated using coronal reformation of CT images in European adult patients without liver disease.

METHODS

One hundred patients (50 men, 50 women; mean age, 47 years) without hepatic disease were included. Coronal and three-dimensional images of the liver were obtained using 64-section helical CT. Correlation between hepatic height and hepatic volume was searched for using the Pearson correlation test. Regression analysis was used to compare hepatic height and hepatic volume.

RESULTS

A strong and highly significant positive correlation was found between hepatic height and hepatic volume, with a correlation coefficient (r) of 0.767 (95%CI 0.672-0.837; r² = 0.588) (P < 0.001). The equation of the correlation line was y = 11.764x - 244 where y represents the hepatic volume in cm³ and x the hepatic height in mm.

CONCLUSION

Hepatic height as obtained on coronal CT image is a simple and rapid measurement that allows predicting hepatic volume in European adult patients without liver disease.

Zero mortality in more than 300 hepatic resections: validity of preoperative volumetric analysis

PURPOSE

We reviewed a series of patients who underwent hepatic resection at our institution, to investigate the risk factors for postoperative complications after hepatic resection of liver tumors and for procurement of living donor liver transplantation (LDLT) grafts.

METHODS

Between April 2004 and August 2007, we performed 304 hepatic resections for liver tumors or to procure grafts for LDLT. Preoperative volumetric analysis was done using 3-dimensional computed tomography (3D-CT) prior to major hepatic resection. We compared the clinicopathological factors between patients with and without postoperative complications.

RESULTS

There was no operative mortality. According to the 3D-CT volumetry, the mean error ratio between the actual and the estimated remnant liver volume was 13.4%. Postoperative complications developed in 96 (31.6%) patients. According to logistic regression analysis, histological liver cirrhosis and intraoperative blood loss >850 mL were significant risk factors of postoperative complications after hepatic resection.

CONCLUSIONS

Meticulous preoperative evaluation based on volumetric analysis, together with sophisticated surgical techniques, achieved zero mortality and minimized intraoperative blood loss, which was classified as one of the most significant predictors of postoperative complications after major hepatic resection.

Total resection of the right hepatic vein drainage area with the aid of three-dimensional computed tomography

PURPOSE

We analyzed the feasibility and safety of our preliminary surgical approach for total hepatic resection of the right hepatic vein drainage area (THR-RHV) with the aid of three-dimensional computed tomography (3D-CT) guidance.

METHODS

Clinical findings and 3D-CT volumetry results were investigated in five patients who underwent THR-RHV for a hepatic malignant tumor close to the right hepatic vein (RHV).

RESULTS

The mean estimated remnant liver volume after a conventional right lobectomy was 474 ml, whereas that after THR-RHV was 614 ml, indicating that 140 ml (13.8%) of additional liver volume had been preserved by performing THR-RHV. The median operative time, mean ischemic time, and mean blood loss during surgery were 406 min, 51 min, and 587 ml, respectively. Histological examinations confirmed a negative surgical margin in all five patients. The mean liver volume estimated by 3D-CT was 458 ml, whereas the mean actual resected liver volume was 468 g, resulting in a mean error ratio of 3.1%.

CONCLUSIONS

THR-RHV allowed for a higher remnant liver volume than that after conventional right lobectomy of the liver, and proved feasible with acceptable perioperative results. This technique thus promotes both safety and curability for patients with a tumor close to the RHV.

Three-dimensional computed tomography analysis of venous collaterals between the middle hepatic vein tributaries and the right hepatic vein in the donor remnant right lobe: report of a case

We report how three-dimensional computed tomography (3D-CT) showed the development of obvious venous collaterals between the middle hepatic vein (MHV) tributaries and the right hepatic vein (RHV) in the remnant right lobe of a donor liver. The donor was a healthy 34-year-old man who donated the left lobe of his liver with the MHV. The 3D-CT calculated that the total drainage of the MHV tributaries was 413 ml, corresponding to 59% of the total remnant liver. The congestion calculated by 3D-CT decreased from 286 ml on postoperative day (POD) 7 to 28 ml on POD 35, corresponding to 36% and 3% of the total remnant liver, respectively. The donor was discharged from hospital with almost normal liver function, and 3D-CT analysis on POD 35 detected obvious venous collaterals between the MHV tributaries and the RHV. These findings suggest that reconstruction of the MHV tributaries in the donor remnant right lobe may not be necessary.

Temporal changes in the stiffness of the remnant liver and spleen after donor hepatectomy as assessed by acoustic radiation force impulse: A preliminary study

AIM

  Virtual touch tissue quantification (VTTQ) is an implementation of ultrasound acoustic radiation force impulse imaging that provides numerical measurements of tissue stiffness. We have evaluated the temporal changes of the remnant liver and spleen after living donor hepatectomy with special reference to the differences between right and left liver donation.

METHODS

  Nineteen living donors who received right lobectomy (small remnant liver [SRL] group; n = 7) or extended left and caudate lobectomy (large remnant liver [LRL] group; n = 12) were enrolled. They underwent measurement of liver and spleen VTTQ before and after donor surgery.

RESULTS

  Virtual touch tissue quantification of the remnant liver increased postoperatively until postoperative day (POD) 3-5, and the values in the SRL group were significantly higher than those in the LRL group at POD 3-9. The values of the spleen also increased after donor surgery and the values in the SRL group were significantly higher than those in the LRL group at POD 3-14. A significant positive correlation between postoperative maximum value of VTTQ and postoperative maximum total bilirubin levels was observed. In liver transplant recipients, there was a significant positive correlation between preoperative spleen VTTQ and the corresponding actual portal venous pressure that was measured at the time of transplant surgery.

CONCLUSION

  Stiffness of the remaining liver and spleen in the smaller remnant liver group became harder than that in the larger remnant liver group. Perioperative measurement of liver and spleen VTTQ seems to be a useful means for assessing the physiology of liver regeneration.

Preoperative estimation of the liver graft weight in adult right lobe living donor liver transplantation using maximal portal vein diameters

An accurate preoperative estimate of the graft weight is vital to avoid small-for-size syndrome in the recipient and ensure donor safety after adult living donor liver transplantation (LDLT). Here we describe a simple method for estimating the graft volume (GV) that uses the maximal right portal vein diameter (RPVD) and the maximal left portal vein diameter (LPVD). Between June 2004 and December 2009, 175 consecutive donors undergoing right hepatectomy for LDLT were retrospectively reviewed. The GV was determined with 3 estimation methods: (1) the radiological graft volume (RGV) estimated by computed tomography (CT) volumetry; (2) the computed tomography-calculated graft volume (CGV-CT), which was obtained by the multiplication of the standard liver volume (SLV) by the RGV percentage with respect to the total liver volume derived from CT; and (3) the portal vein diameter ratio-calculated graft volume (CGV-PVDR), which was obtained by the multiplication of the SLV by the portal vein diameter ratio [PVDR; ie, PVDR = RPVD(2) /(RPVD(2) + LPVD(2) )]. These values were compared to the actual graft weight (AGW), which was measured intraoperatively. The mean AGW was 633.63 ± 107.51 g, whereas the mean RGV, CGV-CT, and CGV-PVDR values were 747.83 ± 138.59, 698.21 ± 94.81, and 685.20 ± 90.88 cm(3) , respectively. All 3 estimation methods tended to overestimate the AGW (P < 0.001). The actual graft-to-recipient body weight ratio (GRWR) was 1.00% ± 0.19%, and the GRWRs calculated on the basis of the RGV, CGV-CT, and CGV-PVDR values were 1.19% ± 0.25%, 1.11% ± 0.22%, and 1.09% ± 0.21%, respectively. Overall, the CGV-PVDR values better correlated with the AGW and GRWR values according to Lin's concordance correlation coefficient and the Landis and Kock benchmark. In conclusion, the PVDR method is a simple estimation method that accurately predicts GVs and GRWRs in adult LDLT.

Morphological and functional MDCT: problem-solving tool and surrogate biomarker for hepatic disease clinical care and drug discovery in the era of personalized medicine

This article explains the significant role of morphological and functional multidetector computer tomography (MDCT) in combination with imaging postprocessing algorithms served as a problem-solving tool and noninvasive surrogate biomarker to effectively improve hepatic diseases characterization, detection, tumor staging and prognosis, therapy response assessment, and novel drug discovery programs, partial liver resection and transplantation, and MDCT-guided interventions in the era of personalized medicine. State-of-the-art MDCT depicts and quantifies hepatic disease over conventional CT for not only depicting lesion location, size, and extent but also detecting changes in tumor biologic behavior caused by therapy or tumor progression before morphologic changes. Color-encoded parameter display provides important functional information on blood flow, permeability, leakage space, and blood volume. Together with other relevant biomarkers and genomics, the imaging modality is being developed and validated as a biomarker to early response to novel, targeted anti-VEGF(R)/PDGFR or antivascular/angiogenesis agents as its parameters correlate with immunohistochemical surrogates of tumor angiogenesis and molecular features of malignancies. MDCT holds incremental value to World Health Organization response criteria and Response Evaluation Criteria in Solid Tumors in liver disease management. MDCT volumetric measurement of future remnant liver is the most important factor influencing the outcome of patients who underwent partial liver resection and transplantation. MDCT-guided interventional methods deliver personalized therapies locally in the human body. MDCT will hold more scientific impact when it is fused with other imaging probes to yield comprehensive information regarding changes in liver disease at different levels (anatomic, metabolic, molecular, histologic, and other levels).