The Resection And Partial Liver Transplantation with Delayed total hepatectomy (RAPID) procedure involves left hepatectomy with orthotopic implantation of a left lobe and right portal vein ligation. This technique induces volumetric graft increase, allowing for a right completion hepatectomy within 15 days. Notably, there is a lack of data on the hemodynamics of small-for-size grafts exposed to portal overflow without triggering small-for-size syndrome.

A prospective single-center protocol included 8 living donors and 8 RAPID noncirrhotic recipients. Comprehensive clinical and biological data were collected, accompanied by intraoperative arterial and portal flow and pressure measurements. Early kinetic growth rate (eKGR%) and graft function were assessed using computed tomography and 99Tc-mebrofenin scintigraphy on postoperative days 7 and 14. Findings were compared with retrospective data from 13 left living donor liver transplantation (LDLT) recipients.

The median Graft-body weight ratio was 0.41% (interquartile range: 0.34-0.49), markedly lower than in LDLT. However, there was no significant difference in eKGR between RAPID and LDLT grafts. Sequential analysis revealed variable eKGR per day: 10.6% (7.8-13.2) in the first week and 7.6% (6-9.1) in the second week posttransplantation. Indexed portal flow (indexed portal vein flow) was significantly higher in RAPID compared with left LDLT ( P = 0.01). No hemodynamic parameters were found to correlate with regeneration speed. We modulated portal flow in 2 out of 8 cases.

This study presents the first report of hemodynamic and volumetric data for the RAPID technique. Despite initial graft volumes falling below conventional LDLT recommendations, the study highlights acceptable clinical outcomes.

Postoperative hepatic insufficiency (PHI) is the most feared complication after hepatectomy. Volume of the future liver remnant (FLR) is one objectively measurable indicator to identify patients at risk of PHI. In this review, we summarized the development and rationale for the use of liver volumetry and liver-regenerative interventions and highlighted emerging tools that could yield new advancements in liver volumetry.

A review of MEDLINE/PubMed, Embase, and Cochrane Library databases was conducted to identify literature related to liver volumetry. The references of relevant articles were reviewed to identify additional publications.

Liver volumetry based on radiologic imaging was developed in the 1980s to identify patients at risk of PHI and later used in the 1990s to evaluate grafts for living donor living transplantation. The field evolved in the 2000s by the introduction of standardized FLR based on the hepatic metabolic demands and in the 2010s by the introduction of the degree of hypertrophy and kinetic growth rate as measures of the FLR regenerative and functional capacity. Several liver-regenerative interventions, most notably portal vein embolization, are used to increase resectability and reduce the risk of PHI. In parallel with the increase in automation and machine assistance to physicians, many semi- and fully automated tools are being developed to facilitate liver volumetry.

Liver volumetry is the most reliable tool to detect patients at risk of PHI. Advances in imaging analysis technologies, newly developed functional measures, and liver-regenerative interventions have been improving our ability to perform safe hepatectomy.

When hepatocellular carcinoma (HCC) is closely associated with the left branch of the portal vein, there is still controversy regarding the surgical approach.

This study enrolled 330 HCC patients with tumors adjacent to the left branch of the portal vein. Among them, 85 patients underwent left hemihepatectomy (LH), while the remaining 235 underwent liver lobectomy (LL), which included left medial segmentectomy or left lateral sectionectomy. Perioperative complications, time to recurrence and overall survival (OS) were compared using propensity score matching.

LH resulted in a lower 5-year recurrence rate and higher 5-year OS rate than LL (56.5% vs 74.0%, p=0.002; 67.4% vs 53.5%, p=0.029). The LL group showed a higher tendency for early recurrence (ER) and intrahepatic recurrence (IR). The cumulative IR rates at 1- 3-, and 5-years for the LH group and the LL group were 17.0%, 36.7%, 45.1% and 33.8%, 57.1%, 63.7%, respectively, with a p-value of 0.007. There was no statistically significant difference in the cumulative ER rates between the two groups at 1-, 3-, and 5- years. Furthermore, the LH group and the LL group had similar perioperative complications, and no cases of liver failure occurred.

LH, compared to LL, reduced the IR rate and ER rate in HCC patients with tumor adjacent to the left branch of the portal vein. It improved the OS outcome of the patients, and there was no significant difference in perioperative complications between the two groups.

Future liver remnant volume (FLRV), a risk factor for liver failure (PHLF) after major hepatectomy (MH), is not routinely measured. This study aimed to evaluate the association between FLRV and PHLF.

All patients undergoing MH (4 + segments) between 2011 and 2018 were identified from a prospectively maintained single-centre database. Perioperative data were collected for patients with PHLF, who were matched (1:2) with non-PHLF controls. FLRV and FLRV% (i.e., % of total liver volume) were calculated retrospectively from preoperative CT scans using Synapse-3D software, and compared between the PHLF and matched control groups.

Of 711 patients undergoing MH, PHLF occurred in 27 (3.8%), of whom 24 had preoperative CT scans available. These patients were matched to 48 non-PHLF controls, 98% of whom were classified as being at high risk of PHLF on preoperative risk scoring. FLRV% was significantly lower in the PHLF group, compared to matched controls (median: 28.7 vs. 35.2%, p = 0.010), with FLRV% < 30% in 58% and 29% of patients, respectively. Assessment of the ability of FLRV% to differentiate between PHLF and matched controls returned an area under the ROC curve of 0.69, and an optimal cut-off value of FLRV% < 31.5%, which yielded 79% sensitivity and 67% specificity.

FLRV% is significantly predictive of PHLF after MH, with over half of patients with PHLF having FLRV% < 30%. In light of this, we propose that all patients should undergo risk stratification prior to MH, with the high risk patients additionally being assessed with CT volumetry.

The aim of this study was to verify the prognostic impact of the tumor exposure at the liver transection margin (LTM) in left-sided perihilar cholangiocarcinoma and the impact of middle hepatic vein (MHV) resection on this exposure.

In perihilar cholangiocarcinoma, tumors are unexpectedly exposed at the LTM during left hemihepatectomy (LH).

Patients who underwent LH for perihilar cholangiocarcinoma during 2002 to 2018 were retrospectively evaluated. LH was classified into conventional and extended types, which preserved and resected the MHVs, respectively. Positive LTM was defined as the involvement of invasive carcinoma at the liver transection plane and/or the adjacent Glissonean pedicle exposed. The clinicopathologic features and survival outcomes were compared between procedures.

Among 236 patients, conventional and extended LHs were performed in 198 and 38 patients, respectively. The LTM was positive in 31 (13%) patients, with an incidence of 14% versus 8% ( P = 0.432) and 24% versus 0% in advanced tumors ( P = 0.011). Tumor size ≥ 18 mm ( P = 0.041), portal vein invasion ( P = 0.009), and conventional LH ( P = 0.028) independently predicted positive LTM. In patients with negative LTM, the survival was comparable between the two groups: 60.4% versus 59.2% at 3 years ( P = 0.206), which surpassed 17.7% for those with positive LTM in the conventional group ( P < 0.001). Multivariable analysis demonstrated that LTM status was an independent prognostic factor ( P = 0.009) along with ductal margin status ( P = 0.030).

The LTM status is an important prognostic factor in perihilar cholangiocarcinoma. Extended LH reduced the risk of tumor exposure at the LTM with a subsequent improvement in the survival, particularly in advanced tumors.

Liver resection has a risk of postoperative hepatic dysfunction, including drug metabolism. Since fentanyl is primarily metabolized in the liver, liver resection requires exercising caution against fentanyl overdose in postoperative analgesia. The rationale for dose adjustment of fentanyl in the preoperative prescription for patients undergoing liver resection remains unclear. We examined whether postoperative fentanyl consumption is associated with the future liver remnant after liver resection and investigated factors influencing fentanyl consumption.

In this retrospective study, 89 living liver donors undergoing open liver resection received intravenous patient-controlled analgesia with fentanyl 2 mg with thoracic epidural analgesia. The primary outcome was postoperative hourly consumption of intravenous patient-controlled analgesia with fentanyl. Future liver remnant volume (ml) and the ratio of future liver remnant volume to whole liver volume (%) were estimated by computed tomography volumetry and compared to determine which correlated more strongly with fentanyl hourly consumption. Multivariable analysis identified independent factors affecting fentanyl consumption, with adjustments for patient characteristics and intravenous patient-controlled analgesia setting.

Future liver remnant volume (ml) was significantly correlated more strongly than the ratio of future liver remnant (%) with postoperative fentanyl consumption (r = 0.53 vs. 0.36, p < 0.001). Larger future liver remnant volume (β = 0.25, p = 0.006) and age < 45 years (β = 0.24, p = 0.009) were independently associated with higher fentanyl consumption, while sex and weight were not.

Future liver remnant volume was significantly associated with postoperative fentanyl consumption. Smaller remnant liver volume and older age (≥ 45 years) were independent factors reducing postoperative fentanyl consumption in patients undergoing open donor hepatectomy.

The aim of this study was to measure the diaphragm volume using three-dimensional computed tomography (3D-CT) and verify its validity.

This was a retrospective study of existing samples.

Participants comprised five male patients, aged 65-70 years, who underwent preoperative chest CT (with a slice thickness of 0.5 mm) before coronary artery bypass surgery. The diaphragm was selectively extracted using a workstation to reconstruct a stereoscopic image, and the total muscle volume was measured. To confirm the accuracy and reproducibility of diaphragm muscle volume measurements on CT, all cases were measured three times by two observers, and intraclass correlation coefficients (ICCs) and interobserver correlations were determined.

Observers #1 and #2 reported an average diaphragm volume of 256.7±33 cm3 and 259.3±36 cm3, respectively. The ICC analyses yielded Cronbach's alphas of 0.992 and 0.981 from both observers, and the interobserver correlation was 0.991. The ICC of a single measurement and the average measurement was 0.984 (95% confidence interval: 0.998-0.884) and 0.992 (95% confidence interval: 0.999-0.939), respectively.

To our knowledge, this study is the first to standardize the method for measuring the total diaphragm volume and examine the reproducibility and validity of the new method. The diaphragm could be selectively extracted and reconstructed. Measurement of the total diaphragm muscle volume using a workstation to reconstruct a stereoscopic image is feasible and highly reproducible. This technique can be reliably employed to evaluate diaphragm volume, thickness, and morphology.

Reports on the future liver remnant (FLR) hypertrophy rate in patients undergoing portal vein embolization (PVE) before left trisectionectomy are sparse. This study aimed to assess the FLR hypertrophy rate in patients undergoing PVE before left trisectionectomy.

Between January 2010 and June 2021, 30 patients (22 men and eight women; mean age, 65.7 years) underwent PVE, mainly using gelatin sponge, before left trisectionectomy. The preoperative diagnosis was cholangiocarcinoma in 28 patients and colorectal liver metastases in two patients. The FLR hypertrophy rate, increase in the FLR volume (FLRV) ratio (the ratio of the FLRV to the total liver volume), and complications were evaluated. The patients were further divided into two groups: one group of patients with left portal vein stenosis or occlusion before PVE (n = 12) and another without left portal vein stenosis or occlusion before PVE (n = 18). The FLR hypertrophy rate and increase in the FLRV ratio were compared between the two groups.

The FLR hypertrophy rate and increase in the FLRV ratio were 31.3% and 6.9%, respectively. One major complication, cholangitis, developed; however, its association with PVE was unclear. The difference in the FLR hypertrophy rate and the increase in the FLRV ratio between the two groups of patients was statistically insignificant.

PVE before left trisectionectomy is effective in achieving FLR hypertrophy. PVE before left trisectionectomy was equally effective in patients with left portal vein stenosis or occlusion as compared to those without. The complication rates were acceptable.

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.

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.

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).

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

For hepatocellular carcinoma (HCC) located in the left lateral lobe, the optimal surgical procedure is still controversial. This study aimed to optimize surgical strategies and to construct a nomogram to predict the postoperative survival of patients with HCC.

Between 1 January 2005 and 30 September 2018, a total of 493 patients were enrolled. Propensity score matching (PSM) was performed between the left lateral lobectomy (LLL) and left hepatectomy (LH) groups (1:1). The study endpoints were overall survival (OS), recurrence-free survival (RFS), and safety. A nomogram was generated using a multivariate Cox proportional hazards model. The discriminative ability and calibration of the nomogram were evaluated using C-statistics and calibration plots.

After matching, 87 pairs were included. The LH group had better 1-, 3-, and 5-year OS rates than the LLL group (88%, 73%, and 69% vs. 73%, 57%, and 49%, respectively; p = 0.017). The 1-, 3-, and 5-year RFS rates of the LH group were similar to those of the LLL group (64%, 49%, and 46% vs. 63%, 51%, and 42%, respectively; p = 0.652). There were no significant differences in postoperative complications. Eight factors were integrated into the nomogram and it had good discriminative ability and calibration.

Our data revealed that compared to LLL, LH may result in better OS and have similar postoperative complications for HCC. The nomogram may serve as a practical tool for the individual prognostic evaluation of patients with HCC.

In living liver donors with rare anatomical anomaly of right-sided ligamentum teres (RSLT), right or left hemiliver procurement is commonly contraindicated. The purpose of this study was to evaluate the hepatic volume profiles in potential donors with RSLT using semi-automated CT volumetry (CTV).

Among 5535 potential donor candidates in our institution between April 2003 and May 2019, 23 cases of RSLT (0.4%) were included. Proportional liver volumes were measured using semi-automated CTV and compared with those of manual volumetry and intraoperative graft weights (seven surgical cases).

The mean percentage volume of the right posterior section was significantly larger than that of the left hemiliver (38.5 ± 8.4% vs. 23.3 ± 5.7%, P < 0.001). Particularly in independent right lateral type, the mean percentage volume of the right posterior section was about two times larger to that of the left hemiliver (41.5% ± 6.5% vs. 21.9% ± 4.4%, P < 0.001), whereas the volume proportions of these two parts were similar between the two parts in bifurcation and trifurcation types (P = 0.810 and 0.979, respectively). Semi-automated CTV of corresponding whole liver, right posterior section, right anterior section, and left hemiliver showed strong correlations with manual CTV (r = 0.989-0.998; P < 0.001). For the seven surgical cases, the graft weights estimated by semi-automated CTV showed a significant correlation with intraoperative graft weights (r = 0.972; P < 0.001).

In independent right lateral type of RSLT, the right posterior section tends to be significantly larger than left hemiliver, and may be an alternative option for graft in potential living liver donors with this rare anatomical anomaly.

More than 400 liver transplants were performed at Asan Medical Center (AMC) in 2011, and over 500 liver transplants including 420 living-donor liver transplants (LDLTs) were performed in 2019. Herein, we report the methodology of these procedures.

Since the first adult LDLTs at AMC using the left and right lobes were successfully performed, various innovative techniques and approaches have been developed: modified right lobe, dual graft, donor exchange for ABO incompatibility, expansion of indications and no-touch techniques for hepatocellular carcinoma, intraoperative cine-portogram and additional intervention for large collaterals, management of portal vein thrombosis (PVT) and stenosis, salvage LDLT after major hepatectomy, and timely LDLT for patients with acute-on-chronic liver failure.

Four hundred twenty LDLTs in 403 adult and 17 pediatric patients and 85 deceased-donor liver transplants in 74 adult and 11 pediatric patients were performed. The number of deceased-donor liver transplants remained constant since 2011, but the number of LDLTs increased steadily. One hundred thirty patients (25.7%) required urgent liver transplantations and 24 patients with acute-on-chronic liver failure underwent LDLT. PVT including grade 1,2,3, and 4 was reported in 91 patients (18.0%), and Yerdel's grade 2, 3, and 4 PVT was reported in 47 patients (51.6%); all patients with PVT were successfully treated. Adult LDLTs for hepatocellular carcinoma and ABO incompatibility accounted for 52.6% and 24.3% of the cases, respectively. In-hospital mortality in 2019 was 2.97%.

Continual efforts to overcome challenging problems in LDLT with various innovations and dedication of the team members during the perioperative period to improve patient outcomes were crucial in increasing the number of liver transplantations at Asan Medical Center.

To determine the accuracy of semiautomated CT volumetry using portal vein (PV) segmentation to estimate volume of the right posterior section (RPS) graft compared to intraoperative measured weight (W) in live liver donors.

Among 23 donors who donated RPS grafts for liver transplantation in our institution from April 2003 to August 2016, 17 donors with CT scans within 3 months of liver procurement and PV anatomy of type I-III were included. RPS volumes were retrospectively evaluated by semiautomated CT volumetry (RPSV_CTV) and by measurement of standard liver volume (SLV) and PV area ratio (RPSV_SLV). RPS volumes were compared to W for correlation coefficients, (absolute) difference, and (absolute) percentage deviation. Linear fitting was performed to identify the method that yielded the greatest correlation with W.

Mean values of RPSV_CTV, RPSV_SLV, and W were 503.4 ± 97.8 mL (346.6-686.0), 516.54 ± 146.20 (274.06-776.32), and 518.8 ± 122.4 (370.0-789.0), respectively. RPSV_CTV was strongly correlated with W (r = 0.9414; p < 0.0001), whereas RPSV_SLV was only moderately did (r = 0.5899; p = 0.0127). RPSV_CTV showed a significantly smaller absolute difference (35.20 ± 30.82 vs. 104.79 ± 60.27, p = 0.004) and absolute percentage deviation (6.61 ± 4.90 vs. 19.92 ± 10.37, p < 0.0001) from W. Equation correlating RPSV_CTV and W was W = -74.7191 + 1.1791 RPSV_CTV (R² = 0.8862; p < 0.001).

RPSV_CTV yields smaller absolute difference than RPSV_SLV for estimating intraoperative measured weight of RPS in live liver donors. Semiautomated CT volumetry using PV segmentation is feasible for the estimation of the volume of the RPS of the liver, and RPSV_CTV was strongly correlated with W (r = 0.9414; p < 0.0001).

Right lobe (RL) living donor liver transplantation (LDLT) usually includes 2 bile duct anastomosis sites, namely, the right anterior and the right posterior segmental ducts. This study aimed to evaluate the optimal treatment for biliary strictures following RL LDLT with respect to unilateral or bilateral drainage techniques. From January 2005 to December 2017, 883 patients at Seoul National University Hospital underwent RL LDLT. Of these, 110 patients were enrolled who had 2 duct-to-duct anastomosis sites and who were considered at risk of developing biliary anastomotic strictures. Unilateral or bilateral biliary drainage during the follow-up period was identified by endoscopic retrograde cholangiopancreatography (ERCP) and/or percutaneous transhepatic biliary drainage (PTBD). The clinical success, complication, and 180-day mortality rates were compared between the unilateral and bilateral biliary drainage groups according to the initial ERCP findings. The mean age at the time of LDLT was 54.2 ± 8.2 years. The median time from LDLT to initial biliary anastomotic strictures was 177 (interquartile range, 18-1085) days. At the initial ERCP, unilateral drainage was performed in 55 (50.0%) patients, and bilateral drainage was performed in 11 (10.0%) patients. Of the patients who underwent unilateral drainage, 35 (63.6%) patients required conversion to bilateral drainage during follow-up. Overall, 71 (64.5%) patients required bilateral drainage more than once, whereas only 27 (24.5%) patients reached a resolution with unilateral biliary drainage. In this study, most patients required bilateral biliary drainage more than once during follow-up. An active attempt should be made to drain bilaterally in patients with biliary anastomotic strictures following RL LDLT.

To predict the rate of liver regeneration after living donor liver transplantation (LDLT) using pre-operative computed tomography (CT) texture analysis.

112 living donors who performed right hepatectomy for LDLT were included retrospectively. We measured the volume of future remnant liver (FLR) on pre-operative CT and the volume of remnant liver (LR) on follow-up CT, taken at a median of 123 days after transplantation. The regeneration index (RI) was calculated using the following equation: [Formula: see text]. Computerized texture analysis of the semi-automatically segmented FLR was performed. We used a stepwise, multivariable linear regression to assess associations of clinical features and texture parameters in relation to RI and to make the best-fit predictive model.

The mean RI was 110.7 ± 37.8%, highly variable ranging from 22.4% to 247.0%. Among texture parameters, volume of FLR, standard deviation, variance, and gray level co-occurrence matrices (GLCM) contrast were found to have significant correlations between RI. In multivariable analysis, smaller volume of FLR (ß - 0.17, 95% CI - 0.22 to - 0.13) and lower GLCM contrast (ß - 1.87, 95% CI - 3.64 to - 0.10) were associated with higher RI. The regression equation predicting RI was following: RI = 203.82 + 10.42 × pre-operative serum total bilirubin (mg/dL) - 0.17 × V_FLR (cm³) - 1.87 × GLCM contrast (× 100).

Volume of FLR and GLCM contrast were independent predictors of RI, showing significant negative correlations. Pre-operative CT with texture analysis can be useful for predicting the rate of liver regeneration in living donor of liver transplantation.

In living-donor liver transplantation (LDLT), the right lobe graft is commonly utilized to prevent small-for-size syndrome, despite the considerable donor morbidity. Conversely, the feasibility of the left lobe graft and the right posterior section graft in smaller-sized recipients is now commonly employed with comparable outcomes to right lobe grafts. The efficacy of the right anterior section graft has rarely been reported.

A 56-year-old man, a heavy alcoholic beverage drinker for 20 years, presented in the emergency department with massive ascites and lethargy. He was previously admitted twice due to bleeding esophageal varices.

He was diagnosed with hepatic encephalopathy coma due to alcoholic liver cirrhosis. The Child-Turcotte-Pugh score was 11 (class C), and the Model for End-stage Liver Disease score was 21.62.

A LDTL was offered to the patient as the best treatment option available. The patient's 26-year-old son was found to be the only donor-compatible candidate for the LDTL.Preoperatively, the right lobe of the donor occupied 76.2% of the total liver volume exposing the donor to a small residual liver volume. The right posterior section and left lobe volumes were insufficient, providing a graft-to-recipient weight ratio of 0.42% and 0.38%, respectively. However, the right anterior section could fulfill an acceptable GRWR of 0.83%. Thus, a living donor right anterior sectionectomy was performed.

Clinical signs and symptoms and liver function improved following anterior section graft transplantation without complications.

The procurement of anterior section graft is technically feasible in selected patients, especially in high-volume liver centers.

BACKGROUND We assessed the prognostic impact of donor age on the outcome of adult living donor liver transplantation (LDLT). MATERIAL AND METHODS The study population comprised adult donor and recipients of right lobe grafts for LDLT performed from January 2005 to December 2016. There were 35 living donors aged ≥50 years (old-age donor group). As a control group, donors in their 20s (young-age donor group) were selected after one-to-one propensity score matching based on sex, model for end-stage liver disease (MELD) score, and primary diagnosis. RESULTS Donor age was 52.5±1.5 years versus 25.4±3.1 years in the old- and young-age donor groups, respectively. Remnant volumes of the 2 groups were 38.9±3.0% versus 38.1±2.9%, respectively (p=0.98). One-month regeneration rate of the remnant liver was 101.1±10.6% versus 104.5±11.8%, respectively (p=0.08), and there was no significant difference in the incidences of donor complications. Mean MELD score was 15 versus 14, respectively (p=0.82). Graft-to-recipient weight ratio was 1.02±0.43 versus 0.91±0.63, respectively (p=0.28). In the recipients, biliary complication occurred in 11.4% versus 8.6%, respectively (p=0.12), and there was no difference in 5-year survival rates of both groups (p=0.15). The 1-week and 1-month regeneration rates of the remnant left liver were 71.6±9.9% and 100.1±10.6% in the old-age group, respectively, whereas those were 80.2±12.1% and 104.5±11.8% in the young-age group, respectively (p=0.08). CONCLUSIONS Right lobe grafts from donors aged ≥50 years showed the usual recovery of graft function but rather delayed liver regeneration. Thus, old-aged donors should be selected prudently after consideration of hepatic resection rate, graft size, and hepatic steatosis.

Surgery remains the gold standard both for delimited hepatocellular carcinoma by selective anatomic liver segentectomy and for colorectal liver metastases by parenchymal sparing liver resection. Right anterior sector (RAS) (segments V-VIII; Couinaud) is the largest and most difficult sector to operate on. A better knowledge of its segmentation could prevent postoperative remnant liver ischemia and its impacts on patient's survival.

A literature search was conducted in PubMed for papers on anatomy and surgery of the right anterior sector.

Segmentation of the RAS depended of the anatomic variations of the third-order portal branches. Cranio-caudal segmentation was the most commonly found (50-53%), followed by ventro-dorsal (23-26%), trifurcation (13-20%), and quadrifurcation types (5-11%). Ventral and dorsal partial or total subsegmentectomy seemed accessible in 47 to 50% of patients, including bifurcation, trifurcation, and quadrifurcation types, and could spare up to 22% of the total liver volume. The RAS hepatic vein was present in 85-100% of the patients and could be used as a landmark between RAS dorsal and ventral part in 63% of patients. Reported overall morbidity rate of RAS subsegmentectomy ranged from 33 to 59% among studies with a postoperative major complication rate (Clavien-Dindo ≥ III) ranging around 18% and a biliary leakage rate from 16 to 21%. In-hospital reported mortality rate was low (0-3%), and results were comparable to "classic" liver resections. RAS subsegmentectomy remains a complex procedure; median operating time ranged from 253 to 520 min and median intraoperative blood loss reached 1255 ml.

Better knowledge of RAS anatomy could allow for parenchymal preservation by using subsegmentectomy of the RAS, selective or as a part of a major hepatectomy.

Primary liver cancer-including hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC)-incidence is increasing and is an important source of cancer-related mortality worldwide. Management of these cancers, even when localized, is challenging due to the association with underlying liver disease and the complex anatomy of the liver. Although for ICC, surgical resection provides the only potential cure, for HCC, the risks and benefits of the multiple curative intent options must be considered to individualize treatment based upon tumor factors, baseline liver function, and the functional status of the patient. The principles of surgical resection for both HCC and ICC include margin-negative resections with preservation of adequate function of the residual liver. As the safety of surgical resection has improved in recent years, the role of liver resection for HCC has expanded to include selected patients with preserved liver function and small tumors (ablation as an alternative), tumors within Milan criteria (transplant as an alternative), and patients with large (>5 cm) and giant (>10 cm) HCC or with poor prognostic features (for whom surgery is infrequently offered) due to a survival benefit with resection for selected patients. An important surgical consideration specifically for ICC includes the high risk of nodal metastasis, for which portal lymphadenectomy is recommended at the time of hepatectomy for staging. For both diseases, onco-surgical strategies including portal vein embolization and parenchymal-sparing resections have increased the number of patients eligible for curative liver resection by improving patient outcomes. Multidisciplinary evaluation is critical in the management of patients with primary liver cancer to provide and coordinate the best treatments possible for these patients.

Liver resection is the treatment of choice for patients with colorectal liver metastases (CLM). However, major resections are often required to achieve R0 resection, which are associated with substantial rates of morbidity and mortality. Maximizing the amount of residual liver gained increasing significance in modern liver surgery due to the high incidence of chemotherapy-associated parenchymal injury. This fact, along with the progressive expansion of resectability criteria, has led to the development of a surgical philosophy known as "parenchymal-sparing liver surgery" (PSLS). This philosophy includes a variety of resection strategies, either performed alone or in combination with ablative therapies. A profound knowledge of liver anatomy and expert intraoperative ultrasound skills are required to perform PSLS appropriately and safely. There is a clear trend toward PSLS in hepatobiliary centers worldwide as current evidence indicates that tumor biology is the most important predictor of intrahepatic recurrence and survival, rather than the extent of a negative resection margin. Tumor removal avoiding the unnecessary sacrifice of functional parenchyma has been associated with less surgical stress, fewer postoperative complications, uncompromised cancer-related outcomes and higher feasibility of future resections. The increasing evidence supporting PSLS prompts its consideration as the gold-standard surgical approach for CLM.

In living donor liver transplantation (LDLT), insufficient graft volume could result in small-for-size syndrome in recipients, whereas major liver donation predisposes the donor to a high risk of posthepatectomy liver failure. Dual graft LDLT is therefore introduced to obtain combined graft sufficiency. To date, 367 patients have been reported worldwide. We reviewed all the relevant literature, with a special focus on 43 case reports containing enough data to extract and analyze. A simple decision-making algorithm was developed. Dual graft LDLT is indicated when (1) a single donation is unacceptable due to graft-to-recipient size mismatch; (2) the future liver remnant is insufficient in the single donor after major resection; or (3) there is a significant underlying disorder or anatomical variation within the donor liver. The outcome of dual graft LDLT is reported to be comparable with that of single donor LDLT. Unilateral graft atrophy was found in 7 of the 43 patients, predominantly in the right-sided, heterotopic and initially smaller grafts. Technically, the heterotopic implantation and complex vascular reconstruction are the most demanding. Elaborate surgical planning and modification are needed. Ethical concerns about involving a second living donor need to be addressed. In conclusion, dual graft LDLT should be prudently performed in select cases by surgeons of proven expertise when single donation is unacceptable and a second living donor is available. The decision-making criteria need to be standardized. More surgical modification and clinical research are needed.

Living donor liver transplantation (LDLT) is widely performed for end-stage liver disease. Liver volume is important for donor safety and recipient survival. In adult-to-adult LDLT, left lobe graft is frequently insufficient for the recipient, while right lobe graft carries a higher donor risk. The right posterior segment graft (RPSG) was introduced to increase donor selection options. However, only a few institutions have reported LDLT with an RPSG.

In total, 587 adult recipients underwent LDLT at Kyoto University Hospital from 2001 to 2011. Here, we retrospectively report 14 LDLT with RPSG. All donors underwent volumetric analyses and detailed investigation of the hepatic vein (HV), portal vein (PV), hepatic artery (HA) and biliary duct (BD). Anatomical anomalies were detected in four donors' BD. The mean Model for End-Stage Liver Disease score was 22.6 ± 12.4 points. ABO blood groups were characterized as incompatible in three cases. The mean graft-to-recipient weight ratio was 0.897 ± 0.203.

Donors' postoperative courses were uneventful. To adjust diameters and lengths between grafts and recipients, dual anastomoses for PV reconstruction and graft interpositions for PV and HA reconstruction were required in one case each. HA thrombosis occurred in two cases and PV thrombosis in one. Biliary complications occurred in two cases. Though there was no significant difference in survival following RPSG versus other grafts, critical complications were observed in recipients.

The RPSG is a useful option in LDLT. However, careful consideration is required for RPSG harvest and LDLT performance, both before and during surgery.

Liver fibrosis and cirrhosis are well-known risk factors for morbidity and mortality after hepatectomy. Fibrosis index based on the four factors (FIB-4) is a non-invasive method for detection of hepatic fibrosis and cirrhosis with high accuracy. This study aimed to evaluate the predictive value of future liver remnant volume ratios (FLRVR)/FIB-4 after liver resection for posthepatectomy outcomes in patients with fibrosis and cirrhosis.

All patients with severe fibrosis or cirrhosis who underwent a liver resection (≥2 segments) were included. Liver insufficiency was defined according to grade C posthepatectomy liver failure (PLF) proposed by the International Study Group of Liver Surgery (ISGLS). Receiver operating characteristic curves and logistic regression model were used to determine the optimal cutoff of FLRVR/FIB-4 and independent risk factors of postoperative outcomes.

The study population consisted of 338 patients. FLRVR/FIB-4 was gradually correlated with short-term outcomes. The optimal value of FLRVR/FIB-4 to predict PLF was 0.13 when considering grade C PLF and postoperative death. A value of 0.24 best predicted postoperative morbidity. At multivariate analysis, FLRVR/FIB-4 remained an independent predictor of PLF (risk ratio(RR) = 0.046; 95% confidence interval (CI): 0.010-0.215; P < 0.001), postoperative morbidity (RR = 0.272; 95% CI: 0.167-0.445; P < 0.001) and mortality(RR =0.058; 95% CI: 0.012-0.277; P < 0.001).

FLRVR/FIB-4 is an independent predictive factor of postoperative outcomes after liver resection in patients with cirrhosis. It is a useful preoperative investigation for risk stratification before hepatectomy.

The variations in the anatomy of the biliary tract need to be recognized in modern liver surgery. The purpose of this clinical and anatomical study is to describe several novel biliary tract variations and to outline their practical importance for liver resections and transplantations.

Over the previous 10 years, the anatomic variations of the bile ducts were examined during 600 intraoperative cholangiographies, 104 segmentectomies and 54 hemihepatectomies in patients with liver diseases. The intraoperative anatomies of the right and left hepatic ducts and the common hepatic duct confluence were analyzed.

Twenty-two variations occurred in 59.5% of the patients. Six variations were described for the first time: an accessory right hepatic duct in which a cystic duct drained; a tetrafurcation from the right anterior hepatic duct, right posterior hepatic duct and bile ducts for Segments 2 and 3 with aberrant bile drainage from Segment 4 into the bile duct for Segment 8; an aberrant bile drainage from Segments 6 and 7 into the common hepatic duct; an accessory bile duct for Segment 6 that drained into the bile duct for Segment 3; a tetrafurcation from the right anterior hepatic duct and the bile ducts for Segments 6, 3 and 2 with bile from Segment 7 draining into the bile duct for Segment 2; and an accessory bile duct for the left hemiliver that drained bile from the Type 4 small accessory hepatic lobe (according to Caygill & Gatenby) into the common hepatic duct.

These newly described biliary tract variations should be recognized by liver surgeons to avoid unwanted postoperative complications.

Living donor liver transplantation (LDLT) continues to evolve, generating interesting issues on the applicability and safety of new techniques.

Specific selection criteria and standardized surgical techniques with high ethical and medical standards are needed to minimize donor risk. In this aspect, minimally invasive donor hepatectomy has caused controversies. The reproducibility and safety of pure laparoscopic major hepatectomy in LDLT remains uncertain. Therefore, a stepwise approach is needed to avoid unnecessary donor risk. To expand the living donor pool, dual graft and ABO-incompatible LDLT have emerged as well tolerated and effective methods. The extended selection criteria for hepatocellular carcinoma in LDLT appear acceptable to balance donor risk and recipient outcome. However, these criteria should be validated based on the risk-benefit ratio. Despite technical advances, technical challenges persist such as Budd-Chiari syndrome and portal vein thrombosis. To address these issues, several innovative surgical techniques have been proposed and have shown promising results.

LDLT is associated with donor safety concerns, technical complexity, and small-for-size issues. Nonetheless, accumulated experience and technical know-how from large-volume Asian LDLT centers have led to progress in LDLT. Further technical refinement and investigation to overcome the disadvantages of partial grafts will broaden the applicability of LDLT.

Right posterior segmental graft (RPSG) is an alternative procedure for living-donor liver transplantation (LDLT). Although the first case of RPSG was reported in 2001, it has not been disseminated because of the lack of popularity, technical concerns, and surgical difficulties.

A 37-year-old man with primary sclerosing cholangitis. His spouse was the only transplantation candidate, although she was ABO incompatible. Preoperative investigations revealed that left-lobe graft was insufficient for the recipient and that right-lobe graft was accompanied by donor risk. In RPSG, estimated graft-to-recipient weight ratio (GRWR) and estimated ratio of liver remnant were reasonable. In the donor operation, the right hepatic vein (RHV) and demarcation line were confirmed, and intraoperative cholangiography was performed. The cut line was carefully considered based on the demarcation line and RHV. The RPSG was harvested. Actual GRWR was 0.54. Unfortunately, this recipient showed a poor course and outcome after LDLT.

Segmental branches of vessels and biliary duct may be not suitable for reconstruction, and surgeons must exercise some ingenuity in the recipient operation. Segmental territory based on inflow and that based on outflow never overlap completely, even in the same segment. The selection of RPSG based only on liver volume may be unfeasible. Liver resection should be carefully considered based on preoperative imaging, and demarcation line and RHV during surgery.

RPSG is a useful tool for LDLT. However, detailed studies before surgery and careful consideration during surgery are important for RPSG harvest.

The estimation of liver volume (LV) has been widely studied in normal liver, the density of which is considered to be equivalent to 1 kg/l. In cirrhosis, volumetric evaluation and its correlation to liver mass remain unclear. The aim of this study was to evaluate the accuracy of computed tomography (CT) scanning to assess LV in patients with cirrhosis.

Liver volume was evaluated by CT (CTLV) and correlated to the explanted liver weight (LW) in 49 patients. Liver density (LD) and its association with clinical features were analysed. Commonly used formulae for estimating LV were also evaluated. The real density of cirrhotic liver was prospectively measured in explant specimens.

Wide variations between CTLV (in ml) and LW (in g) were found (range: 3-748). Cirrhotic livers in patients with hepatitis B virus infection presented significantly increased LD (P = 0.001) with lower CTLV (P = 0.005). Liver volume as measured by CT was also decreased in patients with Model for End-stage Liver Disease scores of >15 (P = 0.023). Formulae estimating LV correlated poorly with CTLV and LW. The density of cirrhotic liver measured prospectively in 15 patients was 1.1 kg/l.

In cirrhotic liver, LV assessed by CT did not correspond to real LW. Liver density changed according to the aetiology and severity of liver disease. Commonly used formulae did not accurately assess LV.

Living donor liver transplantation (LDLT) has been the first option for the patients requiring liver transplantation in East Asia because of the scarcity of cadaveric grafts. We have performed consecutively more than 300 LDLTs per year, and herein report our methods.

In 1997, the first successful adult LDLTs used a left and subsequently a right lobe. However, congestion in the anterior segment of right-lobe grafts prompted us to initiate reconstruction of middle hepatic venous tributaries in 1998. Dual LDLT grafts using 2 left lobes were developed in 2000 to solve graft-size insufficiency and minimize donor risk. The indications for adult LDLT were broadened to near complete obstruction of the portal vein by application of intraoperative cine-portography and portal vein stenting in 2004. ABO-incompatible adult LDLT was initiated in 2008 to overcome the blood group barrier between recipient and donor.

With various innovations at our institution, 317 LDLTs were performed yearly in 2010 and 2011: 301 in 2010 and 298 in 2011. The most common primary diseases was hepatitis B virus-related liver cirrhosis with or without hepatocellular carcinoma (64.3%). The most common graft types were right hemiliver (82.6%). There has been no donor mortality. ABO-incompatible LDLT cases were 11.0% of the total. In-hospital mortality in 2011 was 2.5% (n = 8; adult 6, pediatric 2).

Innovations in operative techniques and perioperative care as well as dedicated team members have made it possible to perform more than 300 LDLTs per year consecutively with excellent outcomes.

For the first time at Asan Medical Center (AMC) we performed more than 400 liver transplantations (LTs) per year in 2011, despite same number of living donor liver transplantations (LDLTs).

Our OLT program was started in 1992, but not activated well due to the scarcity of deceased donor organs. Since adult LDLTs using a left lobe and then a right lobe were successfully performed in 1997, we have developed several innovative techniques and approaches for adult LDLT, for example, modified right-lobe graft reconstructing middle hepatic branches in 1998, dual graft LDLT using 2 left lobes in 2000; new criteria for hepatocellular carcinoma (HCC); as well as ABO-incompatible LDLT, the first in the world. As a result, the number of LDLTs has increased rapidly but reached a plateau recently. Nationwide efforts to promote deceased donation increased the number of deceased donor liver transplantation (DDLT).

We have performed 317 LDLTs per year in 2010 and 2011, respectively. The number of LTs reached 403 in 2011. This large number was possible due to a remarkable increase of DDLTs from 50 in 2010 to 86 in 2011. Seventy-nine patients (68.1%) among 116 patients (28.8%) required an urgent LT receiving a DDLT. LT for HCC or ABO-mismatch comprised 50.3% (n = 150) or 8.7% (n = 35), respectively. In-hospital mortality rate in 2011 was 4.7%.

The increased LTs number at AMC was aided by the nationwide campaign.

A parenchyma-wise technique for the ex vivo procurement of segment 4 (S4) grafts, based on the detailed architecture of the segment, is proposed. Eighteen normal, fresh livers from adult cadavers were injected differentially with colored latex; dissection casts were prepared; and the intricate architecture of S4 was studied. The portal vein elements of the sheath forming most of the inferior part of S4 (S4b) and the superficial major fraction of its superior part (S4a) arose constantly from the medial aspect of the umbilical part of the left portal vein branch. The arterial elements arose constantly from a branch, whose diameter ranged from 2.00 to 3.35 mm (mean = 2.61 ± 0.54 mm) and whose length ranged from 15.15 to 45.65 mm (mean = 27.98 ± 12.13 mm). The biliary elements coalesced as a single duct at the corner, which was formed from the umbilical and transverse parts of the left portal vein branch; the duct's diameter ranged from 2.90 to 6.85 mm (mean = 3.90 ± 1.34 mm). Theoretically, this parenchymal mass-S4b and the superficial fraction of S4a-could be procured for implantation in an infant, and the rest of the liver could be split for an adult and a child. The portal vein branches of the graft would be procured with a patch from the medial aspect of the donor's umbilical portion of the left portal vein branch. This umbilical portion would be reconstructed with a patch from the donor's round ligament. The recipient's portal vein would be reconstructed through the fashioning of a conduit anastomosed with the graft's venous patch.

Computer assisted analysis of organs has an important role in clinical diagnosis and therapy planning. As well as the visualization, the manipulation of 3-dimensional (3D) objects are key features of medical image processing tools. The goal of this work was to develop an efficient and easy to use tool that allows the physician to partition a segmented organ into its segments or lobes. The proposed tool allows the user to define a cutting surface by drawing some traces on 2D sections of a 3D object, cut the object into two pieces with a smooth surface that fits the input traces, and iterate the process until the object is partitioned at the desired level. The tool is based on an algorithm that interpolates the user-defined traces with B-spline surface and computes a binary cutting volume that represents the different sides of the surface. The computation of the cutting volume is based on the multi-resolution triangulation of the B-spline surface. The proposed algorithm was integrated into an open-source medical image processing framework. Using the tool, the user can select the object to be partitioned (e.g. segmented liver), define the cutting surface based on the corresponding medical image (medical image visualizing the internal structure of the liver), cut the selected object, and iterate the process. In case of liver segment separation, the cuts can be performed according to a predefined sequence, which makes it possible to label the temporary as well as the final partitions (lobes, segments) automatically. The presented tool was evaluated for anatomical segment separation of the liver involving 14 cases and virtual liver tumor resection involving one case. The segment separation was repeated 3 different times by one physician for all cases, and the average and the standard deviation of segment volumes were computed. According to the test experiences the presented algorithm proved to be efficient and user-friendly enough to perform free form cuts for liver segment separation and virtual liver tumor resection. The volume quantification of segments showed good correlation with the prior art and the vessel-based liver segment separation, which demonstrate the clinical usability of the presented method.

The aim of this study was to test a new automated hepatic volumetry technique by comparing the accuracies and postprocessing times of manual and automated liver volume segmentation methods in a patient population undergoing orthotopic liver transplantation so that liver volume could be determined on pathology as the standard of reference.

Both manual and automated multiphase MDCT-based volume measurements were strongly correlated to liver volume (Pearson correlation coefficient, r = 0.87 [p < 0.0001] and 0.90 [p < 0.0001], respectively). Automated multiphase segmentation was significantly more rapid than manual segmentation (mean time, 16 ± 5 [SD] and 86 ± 3 seconds, respectively; p = 0.01). Overall, automated liver volumetry based on multiphase CT acquisitions is feasible and more rapid than manual segmentation.

To review our experiences with left-sided hepatectomy for perihilar cholangiocarcinoma, to compare left hepatectomy with left trisectionectomy, and to evaluate the clinical significance of left trisectionectomy from the viewpoint of surgical oncology.

Only 4 large case series have been reported on left trisectionectomy, with only a few patients diagnosed with perihilar cholangiocarcinoma. Therefore, the oncologic advantage of left trisectionectomy compared with left hepatectomy for perihilar cholangiocarcinoma is still unclear.

This study involved 201 patients who underwent left-sided hepatectomy for perihilar cholangiocarcinoma (86 trisectionectomies and 115 hepatectomies). Surgical outcome and survival were compared between the 2 types of hepatectomy. The length of the resected right posterior bile duct was also measured.

Patients who underwent trisectionectomy had more advanced tumors, thus requiring combined vascular and/or other organ resection. Operative time and blood loss were significantly greater in trisectionectomy than in hepatectomy; therefore, overall morbidity was significantly higher in the former (59.3% vs 33.0%, P < 0.001). Mortality was similar (1.2% vs 0.9%) in both techniques. The length of the resected supraportal right posterior bile duct was significantly longer in trisectionectomy than in hepatectomy (20.7 ± 6.4 vs 13.6 ± 5.2 mm, P < 0.001). However, there was no difference in length of the infraportal type right posterior bile duct. The percentage of negative radial and distal common bile duct margins was similar, but the percentage of negative right posterior bile duct margins was significantly higher in trisectionectomy than in hepatectomy (97.7% vs 89.6%, P = 0.027). Overall, R0 resection was achieved in 84.9% of patients with trisectionectomy and in 70.4% of patients with hepatectomy (P = 0.019). Survival rates were similar between patients with trisectionectomy and those with hepatectomy (36.8% vs 34.0% at 5-year), despite the fact that the former had more advanced disease.

Left trisectionectomy for perihilar cholangiocarcinoma, although technically demanding, can be performed with similar mortality rates as left hepatectomy. From an oncologic viewpoint, this operation can increase the number of negative proximal ductal margins, leading to a high proportion of R0 resection, and, in turn, to improved survival rates of patients with advanced left-sided perihilar cholangiocarcinoma.

Right lobe donations are known to expose the donors to more surgical risks than left lobe donations. In the present study, the effects of remnant volume on donor outcomes after right lobe living donor hepatectomies were investigated.

The data on 262 consecutive living liver donors who had undergone a right hepatectomy from January 2004 to June 2011 were retrospectively analysed. The influence of the remnant on the outcomes was investigated according to the two different definitions. These were: (i) the ratio of the remnant liver volume to total liver volume (RLV/TLV) and (ii) the remnant liver volume to donor body weight ratio (RLV/BWR). For RLV/TLV, the effects of having a percentage of 30% or below and for RLV/BWR, the effects of values lower than 0.6 on the results were investigated.

Complication and major complication rates were 44.7% and 13.2% for donors with RLV/TLV of ≤30%, and 35.9% and 9.4% for donors with RLV/BWR of < 0.6, respectively. In donors with RLV/TLV of ≤30%, RLV/BWR being below or above 0.6 did not influence the results in terms of liver function tests, complications and hospital stay. The main impact on the outcome was posed by RLV/TLV of ≤30%.

Remnant volume in a right lobe living donor hepatectomy has adverse effects on donor outcomes when RLV/TLV is ≤30% independent from the rate of RLV/BWR with a cut-off point of 0.6.

Most of the pediatric LT grafts consist in a LLS. Liver graft size matching is one of the major factors determining a successful outcome. The aim of our study was to assess whether anthropometric parameters can be used to estimate the LLS weight. A total of 122 donors (48F/74M) from two transplantation centers were retrospectively reviewed. Eighteen were living related donors (LRLT) and 104 DDs. The donor age was 28.2 yr (range 15-63). The BW and height were, respectively, 70.1 kg (range 45-111) and 172.7 cm (range 152-197). The WLW (n = 66) was 1462 g (range 921-2340), and the liver-to-BW ratio was 2% (range 1.45-2.8%). The LLS graft weight was 313 g (range: 183-537 g). The ratio between LLS and BW was 0.452% (range 0.27-0.74). The LLS represented 22.3% of the WLW with a large variability (range 15.4-31.3%). None of the developed models (linear, nonlinear, or multiple) was clinically usable. The LLS weight is highly variable and is not predictable using simple anthropometric variables. When available, we propose that ultrasonographic estimation of the liver volume should be performed when a liver splitting is considered.

To determine the feasibility of volumetric criteria without anatomic exclusion for the selection of right posterior sector (RPS) grafts for adult-to-adult living donor liver transplantation (LDLT), we reviewed and compared our transplant data for RPS grafts and right lobe (RL) grafts. Between January 2008 and September 2010, adult-to-adult LDLT was performed 65 times at our institute; 13 of the procedures (20%) were performed with RPS grafts [the posterior sector (PS) group], and 39 (60%) were performed with RL grafts (the RL group). The volumetry of the 13 RPS donor livers showed that the RPS volume was 39.8% ± 7.6% of the total liver volume. Ten of the 13 donors had to donate RPS grafts because the left liver volume was inadequate. All donor procedures were performed successfully, and all donors recovered from hepatectomy. However, longer operative times were required for the procurement of RPS grafts versus RL grafts (418 ± 40 versus 345 ± 48 minutes, P < 0.001). The postoperative recovery of liver function was smoother for the donors of the PS group versus the donors of the RL group. The RPS grafts had significantly smaller hepatic artery and bile duct openings than the RL grafts. All recipients with RPS grafts survived LDLT. No recipients experienced vascular graft complications or small-for-size graft dysfunction. There were no significant differences in the incidence of posttransplant complications between the donors and recipients of the PS and RL groups. The 3-year graft survival rates were favorable in both groups (100% in the PS group versus 91% in the RL group). In conclusion, the selection of RPS grafts by volume criteria is a feasible strategy for an adult-to-adult LDLT program.

The purpose of this study is to assess the accuracy, precision, and rapidity of liver volumes calculated by using a freehand electromagnetic pen tablet contourtracing method as compared with the volumes calculated by using the standard optical mouse contourtracing method. The imaging data used as input for accuracy and precision testing were computed by software developed in our institution. This computer software can generate models of solid organs and allows both standard mouse-based and electromagnetic pen-driven segmentation (number of data sets, n = 70). The images used as input for rapidity testing was partly computed by modeling software (n = 70) and partly selected from contrast-enhanced computed tomography (CT) examinations (n = 12). Mean volumes and time required to perform the segmentation, along with standard deviation and range values with both techniques, were calculated. Student's t test was used to assess significance regarding mean volumes and time calculated by using both segmentation techniques on phantom and CT data sets. P value was also calculated. The mean volume difference was significantly lower with the use of the freehand electromagnetic pen as compared with the optical mouse (0.2% vs. 1.8%; P < .001). The mean segmentation time per patient was significantly shorter with the use of the freehand electromagnetic pen contourtracing method (354.5 vs. 499.1 s on phantoms; 457.4 vs. 610.0 s on CT images; P < .001). Freehand electromagnetic pen-based volumetric technique represents a technologic advancement over manual mouse-based contourtracing because of the superior statistical accuracy and sensibly shorter time required. Further studies focused on intra- and interobserver variability of the technique need to be performed before its introduction in clinical application.

Preoperative portal vein embolization (PVE) is increasingly used to optimize the volume and function of the future liver remnant (FLR) and to reduce the risk for complications of major hepatectomy for hepatocellular carcinoma (HCC) or hilar cholangiocarcinoma (CCA). In patients with HCC who are candidates for extended hepatectomy and in patients with HCC and well-compensated cirrhosis who are being considered for major hepatectomy, FLR volumetry is routinely performed, and PVE is employed in selected cases to optimize the volume and function of the FLR prior to surgery. Similarly, in patients with hilar CCA who are candidates for extended hepatectomy, careful preoperative preparation using biliary drainage, FLR volumetry, and PVE optimizes the volume and function of the FLR prior to surgery. Appropriate use of PVE has led to improved postoperative outcomes after major hepatectomy for these diseases and oncological outcomes similar to those in patients who undergo resection without PVE. Specific indications for PVE are being clarified. FLR volumetry is necessary for proper selection of patients for PVE. Analysis of the degree of hypertrophy of the FLR after PVE (a dynamic test of liver regeneration) complements analysis of the pre-PVE FLR volume (a static test). Together, FLR degree of hypertrophy and FLR volume are the best predictors of outcome after major hepatectomy in an individual patient, regardless of the degree of underlying liver disease. This article synthesizes the literature on the approach to patients with HCC and CCA who are candidates for major hepatectomy. The rationale and indications for FLR volumetry and PVE and outcomes following PVE and major hepatectomy for HCC and CCA are discussed.

To evaluate whether a low postoperative platelet count is associated with a poor recovery of liver function in patients after partial liver resection.

Experimental studies in rodents have recently suggested that blood platelets play a critical role in the initiation of liver regeneration. It remains unclear whether platelets are also involved in liver regeneration in humans.

In a series of 216 consecutive patients who underwent partial liver resection for colorectal liver metastases, we studied postoperative mortality and liver dysfunction in relation to the immediate postoperative platelet count. All patients had normal preoperative liver function and none of them had liver fibrosis or cirrhosis. Delayed postoperative recovery of liver function was defined as serum bilirubin >50 micromol/L or prothrombin time >20 seconds at any time point between postoperative day 1 and 5.

Patients with a low (<100 x10(9)/L) immediate postoperative platelet count had worse postoperative liver function, higher serum markers of liver injury, and increased mortality compared with patients with normal platelet counts (>100/L). A low immediate postoperative platelet count was identified as an independent risk factor of delayed postoperative recovery of liver function (OR, 11.5; 95% CI, 1.1-122.4; P = 0.04 in multivariate analysis).

After partial liver resection, a low platelet count is an independent predictor of delayed postoperative liver function recovery and is associated with increased risk of postoperative mortality. These clinical findings are in accordance with the accumulating evidence from experimental studies, indicating that platelets play a critical role in liver regeneration.

To evaluate liver volume alterations and liver function after right portal vein embolization (PVE) during mid-term follow-up based on embolization score.

Computed tomography (CT) images and liver function profiles were obtained before PVE, and at short-term (7-45 days), and mid-term follow-up (106-380 days) after PVE in all 30 patients. The patients were divided into group A (PVE score >or=3, n=20) and group B (PVE score <3, n=10). High score indicates more complete embolization.

Left liver volume (LLV) and percentage future liver remnant (%FLR) increased significantly between pre-PVE and short-term follow-up and between short-term and mid-term follow-up in group A. Increase in FLR volume was significantly higher at the mid-term follow-up than at the short-term follow-up in group A. The ratio of embolized to total liver volume (RETLV) on short-term follow-up was significantly higher in group A than in group B. Aspartate transaminase (AST) and alanine transaminase (ALT) were elevated on short-term follow-up, whereas at mid-term follow-up in group A, they had significantly returned to the baselines.

PVE resulted in continued compensatory hypertrophy of the unembolized liver during the 6-month follow-up. Compensatory hypertrophy in the unembolized liver was proportional to the ratio of embolization and to the embolized liver volume.