Imaging Validation of Drug-Eluting Beads Transarterial Chemoembolization of Hepatocellular Carcinomas in Living Donor Liver Transplantation.

OBJECTIVE: The aim of this study is to determine whether post-transarterial chemoembolization imaging (computed tomography or magnetic resonance imaging) could accurately predict the tumors' necrosis on pathologic specimens. BACKGROUND: Transarterial chemoembolization with drug-eluting beads has been proven to be an effective way to bridge patients with hepatocellular carcinomas to liver transplantation. MATERIALS AND METHODS: From September 2012 to June 2017, 59 patients with a total of 78 hepatocellular carcinomas, who received transarterial chemoembolization with drug-eluting beads before liver transplantation in Kaohsiung Chang Gung Memorial Hospital, were included in the study. All patients and hepatocellular carcinomas have pre-transarterial chemoembolization and post-transarterial chemoembolization images (computed tomography or magnetic resonance imaging) and pathological findings for correlation. Tumor response was evaluated according to modified Response Evaluation Criteria in Solid Tumors. The ranges of necrotic percentage are 100%, 91-99%, 51-90%, and <50%. RESULTS: The accuracy rate between the imaging and pathology correlation was 40% for computed tomography and 42% for magnetic resonance imaging. The recurrent rate of the complete respond group is 11.5%, the partial respond group is 16.0%, and the stationary group is 28.6%. CONCLUSION: Computed tomography and magnetic resonance imaging sensitivity is not satisfactory for microscopic evaluation of residual tumors after transarterial chemoembolization with drug-eluting beads. However, survival is good after liver transplantation no matter what the microscopic findings were.

Diffusion-Weighted Magnetic Resonance Imaging in Liver Graft Rejection.

OBJECTIVE: The purpose of this study is to evaluate the use of diffusion-weighted magnetic resonance imaging (DWMRI) in the assessment of graft rejection after liver transplantation (LT). METHODS: From June 2017 to January 2018, 32 patients were included in the study with a mean age of 52.3 years. All patients underwent LT. The DWMRI was performed using the apparent diffusion coefficient map and measuring the different b-values (b-400, b-600, b-800, and b-1000). These measurements were compared with the histopathology results. Statistical analysis included t test, analysis of variance, and area under the curve for receiver operating characteristic (ROC). RESULTS: There were 17 patients without rejection and 15 patients with liver graft rejection diagnosed by histopathology. The mean (SD) results between the nonrejection and rejection groups were as follows: b-400 = 1.568 (0.265) vs 1.519 (0.119) (P = .089), b-600 = 1.380 (0.181) vs 1.284 (0.106) (P = .039), b-800 = 1.262 (0.170) vs 1.170 (0.086) (P = .035), b-1000 = 1.109 (0.129) vs 1.098 (0.078) (P = .095); B-values × 10-3 mm2/s. Only b-600 (P = .04) and b-800 (P = .04) values have significant differences between the 2 groups. B-600 showed 90.48% sensitivity and 83.33% specificity (ROC area under the curve = 0.784; P < .001), and b-800 showed 90.38% sensitivity and 83.03% specificity (ROC area under the curve = 0.816; P < .001). The values obtained with the apparent diffusion coefficient in b-800 were clearly differentiated between the mild, moderate, and severe degrees of rejection (P < .001). CONCLUSION: Measurement of b-600 and b-800 values using DWMRI may be used for the diagnosis of graft rejection after LT.

Impact of Different Dominant Hepatic Vein Patterns in Left-Lobe Donors of Adult Living Donor Liver Transplantation.

OBJECTIVE: Optimal hepatic venous tributary flow is correlated with liver function and regeneration. In left-lobe graft living donor liver transplantation, the stump of segment 5 and 8 hepatic veins (S5V and S8V) are ligated without performing hepatic tributary reconstruction. The aim of this article was to evaluate the different dominate hepatic vein patterns that affect left-lobe living donor safety. MATERIALS AND METHODS: A total of 44 donors who underwent left-lobe hepatectomy were divided into 2 groups, middle hepatic vein (MHV) dominance (group 1) and right hepatic vein (RHV) dominance (group 2), according to the dominant venous territory drainage from S5V and S8V or RHV. The clinical pathological data, postoperative laboratory data, complication, remnant liver volume and remnant liver regeneration rate at 6 months after surgery were compared. RESULTS: No difference was found in blood loss, postoperative liver function such as alanine transaminase value, complications, and hospital stays between groups. Group 1 had slightly higher total bilirubin level than group 2 (1.99 vs 1.79; P = .49). Group 2 had significantly better remnant liver regeneration rate than group 1 (89.2% vs 82.5%; P = .026). CONCLUSION: It is important to recognize the dominant MHV group. Ligation large S5V and S8V in dominant MHV donors led to lower remnant liver regeneration in our series. This might be critical in extremely small RHV territory and potential large remnant liver congestion donors. Adjusting surgical planning, such as hepatic vein reconstruction, in this kind of donor might be appropriate for donor safety.

Magnetic Resonance Spectroscopy in Living-Donor Liver Transplantation.

OBJECTIVE: The purpose of this study is to evaluate the accuracy rate of the one breath-hold single voxel hydrogen-1 magnetic resonance spectroscopy (MRS) in comparison with intraoperative biopsy for liver fat quantification in living-donor liver transplantation. MATERIALS AND METHODS: A total of 80 living liver donors participated in this study. Each patient underwent both MRS and intraoperative biopsy for evaluation of liver fatty content. MRS was performed using 1.5-T magnetic resonance imaging and placed in segments 2-4, 5-8, and left lateral segment for each donor. Accuracy was assessed through receiver operating characteristic curve analysis. Sensitivity and specificity of MRS fat fractions were also calculated. RESULTS: Eighty living-donor liver transplantation donors were enrolled in this study. There was no fatty liver in 59 subjects (73.8%), 5% to 10% fatty liver in 17 subjects, 11% to 15% fatty liver in 3 subjects, and >16% fatty liver in 1 subject. MRS fat fraction showed excellent parameters to predict between normal liver and fatty liver groups (1.85% ± 0.98, 8.13% ± 3.52, respectively; P < .0001). Linear regression between MRS fat fraction and pathology grading showed high correlation (R(2) = 0.7092). Pearson correlation revealed high correlation between MRS and pathology results (r = 0.936), poor correlation between body mass index and pathology results (r = 0.390). The sensitivity and specificity for detection of liver steatosis in MRS fat fraction were 95.2% and 98.3%, respectively. CONCLUSION: (1)H MRS fat fraction is a highly precise and accurate method in quantification of hepatic steatosis for the living donor and can be finished in a single breath-hold.

Pharmacokinetic Analysis of Dynamic Contrast-Enhanced Magnetic Resonance Imaging for Distinguishing Hepatocellular Carcinoma From Cholangiocarcinoma in Pre-Liver Transplantation Evaluation.

OBJECTIVE: Liver transplantation for intrahepatic cholangiocarcinoma is notorious for rapid recurrence with poor survival rate postoperatively and has therefore been discontinued in most centers. The purpose of this study is to distinguish hepatocellular carcinoma (HCC) from cholangiocarcinoma in pretransplantation imaging evaluation by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). MATERIALS AND METHODS: From January 2014 to September 2015, 19 patients were included in the study, with a mean age of 62.8 years. All subjects underwent pretransplantation DCE-MRI and surgical excision or core biopsy. The DCE-MRI parameters were measured using the Tofts model 1999. Statistical analysis included nonparametric tests and area under the curve for the receiver operating characteristic. RESULTS: Fourteen HCCs and 5 cholangiocarcinomas were diagnosed by surgical pathology. The mean size of tumor was 6.4 cm (range, 1.5 cm to 13.7 cm). All DCE-MRI parameters were calculated as the ratio between the tumor and normal liver parenchyma and K(trans) (1/min) was used as a distinguishing parameter between the two tumors. K(trans) was higher in the cholangiocarcinoma group (1.89 ± 1.13) than in the HCC group (0.46 ± 0.35). Univariate analysis revealed that K(trans) has a high significant difference (P = .001). The optimal K(trans) value cutoffs were 1 or more (area under the curve = 0.971) for detection of HCCs or cholangiocarcinomas. CONCLUSION: The analysis of DCE-MRI with the kinetic model (Tofts, 1999) presents a new and practical approach indiscrimination of HCC from cholangiocarcinoma for pretransplantation imaging evaluation.

Impact of Graft Type in Living Donor Liver Transplantation: Remnant Liver Regeneration and Outcome in Donors.

OBJECTIVES: Liver regeneration and donor safety in right-lobe (RL) and left-lobe (LL) grafts are essential for donors in living donor liver transplantation (LDLT). Our aim was to compare the liver regeneration rate and postoperative outcome between different donor graft types in LDLT. MATERIALS AND METHODS: A total of 95 donors were divided into 2 groups: RL (n = 42) and LL (n = 53). The remnant liver of LL donors were subdivided into 3 subgroups according to the different hepatic venous drainage pattern that dominates from right hepatic vein (dominant RHV; n = 34), middle hepatic vein (dominant MHV; n = 10), and include MHV for left lateral segment (LLS) graft (n = 9). The demographic data, postoperative laboratory data, complications, remnant liver volume (RLV), and remnant liver regeneration rate (RLRR) 6 months after surgery were compared. RESULTS: The postoperative total bilirubin (TB), prothrombin time (PT), and intensive care unit (ICU) stays of the LL group were lower than the RL group (P < .05). The LL group has no significant better regeneration rate 6 months after surgery than the RL group. However, dominant RHV and LLS groups have significantly better RLRR than the RL group (89.2% vs 86% and 95.1% vs 86%, respectively, P < .05), but no significance in the dominant MHV group. CONCLUSION: In conclusion, different hepatic venous drainage patterns of remnant liver grafts may affect the regeneration rate in LL LDLT, especially with dominant RHV donors, may have more comparable outcomes with that of RL, and should be a favorable option during donor selection.

Noncontrast Magnetic Resonance Angiography Using Inflow Sensitive Inversion Recovery Technique for Vascular Evaluation in Pre-liver Transplantation Recipients.

OBJECTIVE: Vascular anatomy is essential in pretransplantation survey. The purpose of this study is to investigate the feasibility and diagnostic performance of inflow sensitive inversion recovery (IFIR) magnetic resonance angiography (MRA) to evaluate the recipient's hepatic vasculature before liver transplantation. MATERIALS AND METHODS: Thirty-one pre-liver transplantation patients underwent both IFIR and conventional contrast-enhanced MRA using a 1.5T MR scanner from December 2012 to December 2014. The contrast-to-noise ratios (CNRs) between liver parenchyma and hepatic vasculature were calculated. The image sets of IFIR and contrast-enhanced MRA were assessed for subjective image quality and depiction of hepatic vasculature on vessel-to-vessel basis by two independent radiologists. RESULTS: The quantitative results of CNR for hepatic arteries on IFIR were significantly lower than contrast-enhanced MRA, whereas CNR for portal veins and inferior vena cava on IFIR were significantly higher than contrast-enhanced MRA. For subjective assessment of image quality, the overall agreement of scores of IFIR and contrast-enhanced MRA was substantial (kappa values ranged from 0.650 to 0.767). There was no significant difference in the image quality for portal veins between IFIR and contrast-enhanced MRA. The quality scores of IFIR were significantly lower than contrast-enhanced MRA for hepatic arteries. For inferior vena cava evaluation, the scores of IFIR were significantly higher than contrast-enhanced MRA. CONCLUSION: IFIR MRA is a reproducible and noninvasive tool to assess the hepatic vasculature that can provide adequate to good image quality. In pre-liver transplantation patients, IFIR MRA becomes even more useful if contrast medium is a contraindication due to impaired renal and liver functions.

Combined Hepatocellular Carcinoma and Cholangiocarcinoma: Diagnosis and Prognosis After Resection or Transplantation.

BACKGROUND: Primary liver malignancy is the leading cause of cancer death worldwide, with hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) representing the majority. Combined HCC-CC, in contrast, accounts for less than 5% of these liver cancers and has not been clearly characterized by imaging, making diagnosis and management difficult. MATERIALS AND METHODS: This retrospective study investigated 32 patients with early-stage combined HCC-CC tumor who underwent hepatectomy (n = 24) or liver transplantation (n = 8). Preoperative imaging and pathologic reports were retrospectively reviewed and correlated. Survival and recurrence rates were then analyzed. RESULTS: Twelve patients with more than 50% CC component showed typical CC enhancement, whereas 17 patients with less than 50% CC component exhibited typical HCC enhancement. Those with equivocal imaging findings resulted near equal tumor component. The majority demonstrated either heterogeneous or peripheral enhancement. Considering the major tumor component, 66% of the images were consistent with histopathology. The over-all 3-year recurrent rate was 59%, with a mean time to recurrence of about 7 months. The 3-year survival rate of combined tumor after hepatectomy was 76% and after transplant was 75%, regardless of major tumor component. However, patients with more than 50% CC component showed a decrease in 3-year survival rate to 50% when transplantation was performed. CONCLUSION: The overall survival rate for combined tumor after either hepatectomy or transplantation seems to be satisfactory but carries a high risk of recurrent when compared to pure HCC. On the other hand, a major CC component tumor after transplantation is associated with poor survival outcome; thus, liver transplantation has no role and is not a good management option.

Portal venous pressure in adult living donor liver transplantation.

OBJECTIVE: The relationship between portal pressure and small-for-size syndrome (SFSS) is unsettled. The purpose of this study was to evaluate the role of portal pressure in predicting SFSS. METHODS: Thirty-four patients with end-stage liver disease who received adult-to-adult living-donor liver transplantation (ALDLT) were included. Recipients were grouped based on whether they received portal flow modulation or not. The intraoperative portal vein flow volume (PVFV) and portal venous pressure (PVP) between the 2 groups were compared. The relationship of PVP to PVFV, graft weight-to-recipient weight ratio (GRWR), and graft weight-to-recipient spleen size ratio (GRSSR) were analyzed. RESULTS: Persistent portal hypertension was found after ALDLT. The PVP was linearly correlated with PVFV but not with GRWR or GRSSR. With the use of the following criteria, (1) PVFV >250 mL/min/100 g graft weight, (2) GRWR <0.8%, and (3) GRSSR <0.6, modulation of the portal flow was performed in 3 cases. The receiver operating characteristic analysis showed that 23 mm Hg was the cutoff point for PVP, with a sensitivity of 83% and specificity of 43%. CONCLUSIONS: PVP is a weak parameter to use for portal flow modulation after ALDLT. It is sensitive but not specific to predict SFSS.

Graft regeneration in pediatric living donor liver transplantation.

OBJECTIVE: Due to the shortage of cadaver liver grafts in Asia, more than 90% of biliary atresia (BA) patients require living donor liver transplantation (LDLT), but the factors that influence liver graft regeneration in pediatric patients are still unclear. The aim of this study was to evaluate the potential predisposing factors that encourage liver graft regeneration in pediatric liver transplantation (LT). METHODS: Case notes and Doppler ultrasound and computed tomography studies performed before and 6 months after transplantation of 103 BA patients who underwent LDLT were reviewed. The predisposing factors that triggered liver regeneration were compiled from statistical analyses and included the following: age, gender, body weight and height, spleen size, graft weight-to-recipient weight ratio (GRWR), post-transplantation total portal flow, and vascular complications. RESULTS: Seventy-two pediatric recipients were enrolled in this study. The liver graft regeneration rate was 29.633 ± 36.61% (range, -29.53-126.27%). The size of the spleen (P = .001), post-transplantation portal flow (P = .004), and age (P = .04) were correlated lineally with the regeneration rate. The GRWR was negatively correlated with the regeneration rate (P = .001) and was the only independent factor that affected the regeneration rate. When the GRWR was >3.4, patients tended to have poor and negative graft regeneration (P = .01). CONCLUSION: Large-for-size grafts have negative effect on regeneration rates because liver grafts that are too large can compromise total portal flow and increase vascular complications, especially when the GRWR is >3.4. Thus, optimal graft size is more essential than other factors in a pediatric LDLT patient.

Predictive factors for persistent splenomegaly and hypersplenism after adult living donor liver transplantation.

PURPOSE: The aim of this study was to evaluate predictive factors for persistent splenomegaly and hypersplenism after living donor liver transplantation (LDLT). PATIENTS AND METHODS: From January 2008 to June 2010, 159 adult patients (116 males and 43 females) who underwent living donor liver transplantation (LDLT) had pre- and post-LDLT computed tomography angiography and survived more than 6 months. Patients with post-LDLT portal vein stenosis were excluded from this study. We analyzed the impact for persistent splenomegaly and hypersplenism after LDLT of pre-LDLT spleen volume, main portal vein (PV) size, coronary vein (CV) size and platelet levels. RESULTS: While 38 patients displayed splenomegaly, 121 showed normal spleen volumes at 6 months after LDLT (LDLT). There were 119 thrombocytopenic versus 40 normal platelet patients at 6 months post-LDLT. The persistent splenomegaly patients showed significantly larger pre-LDLT spleen volume, larger PV and CV sizes as well as lower platelet levels before (×10,000/mL) and 1 month after LDLT (×10,000/mL). Multiple logistic regression analysis showed spleen volume and platelet count at 1 month posttransplant to be the only variables associated with persistent splenomegaly at 6 months post. Persistent thrombocytopenia at 6 months post-LDLT was associated with significantly larger pre-LDLT spleen volume, larger CV size, and lower platelet levels including P0 and P1 m. Multiple logistic regression analysis showed that platelet count at 1 week and at 1 month post-LDLT were the variables associated with persistent thrombocytopenia at 6 months post-LDLT. CONCLUSION: Spleen volume and platelet levels at 1 month after LDLT may predict persistent splenomegaly at 6 months post-LDLT. The predictive factors for hypersplenism at 6 months post-LDLT may be platelet levels at 1 week and at 1 month post-LDLT.

Hepatocellular carcinoma downstaging in liver transplantation.

BACKGROUND: Hepatocellular carcinoma (HCC) is the leading malignant tumor in Taiwan. The majority of HCC patients are diagnosed in late stages and therefore in eligible for potentially curative treatments. Locoregional therapy has been advocated as an effective treatment for patients with advanced HCCs. PURPOSE: The aim of this study was to evaluate the outcomes of HCC downstaged patients after locoregional therapy to allow eligibility for liver transplantation. METHODS AND MATERIALS: From January 2004 to June 2010, 161 patients with HCCs underwent liver transplantation including 51 (31.6%) who exceeded the University of California-San Francisco (UCSF) who had undergone successful locoregional therapy to be downstaged within these criteria. Among the downstaged patients, 48 (94.1%) underwent transarterial embolization; 7 (13.8%), percutaneous ethanol injection; 24 (47.1%), radiofrequency ablation; 15 (29.4%), surgical resection, and 34 (66.7%), combined treatment. RESULTS: The overall 1- and 5-year survival rates of all HCC patients (n=161) were 93.2% and 80.5%. The overall 1- and 5-year survival rates of downstaged (n=51) versus non-downstaged (n=110) subjects were 94.1% versus 83.7% and 92.7% versus 78.9%, respectively (P=.727). There are 15 (9.2%) HCC recurrences. The overall 1- and 5-year tumor-free rates of all HCC patients were 94.8% and 87.2%. The overall 1- and 5-year tumor-free rates between downstaged versus non-downstaged patients were 93.9% and 90.1% versus 95.2% and 86.0%, respectively (P=.812). CONCLUSION: Patients with advanced HCC exceeding the UCSF/Milan criteria can be downstaged to fit the criteria using locoregional therapy. Importantly, successfully downstaged patients who are transplanted show excellent tumor-free and overall survival rates, similar to fit-criteria group.

Biliary complications and management in pediatric living donor liver transplantation for underlying biliary atresia.

BACKGROUND: Biliary complications are a major problem in pediatric liver transplantation. The aim of this study was to evaluate the management and outcomes of biliary complication after pediatric living donor liver transplantation (LDLT). METHODS: From 1994 to 2010, 157 pediatric LDLT due to biliary atresia were performed in our center. Doppler ultrasound was initially performed daily for 2 weeks postoperatively to evaluate biliary and vascular complications. Computed tomography and or magnetic resonance cholangiography were performed when complications were suspected. They were treated using radiological or surgical interventions. RESULTS: Among the 157 cases, we observed 10 (6.3%) biliary complications, which were divided into three groups: bile leakage (n=3); biliary stricture without vascular complication (n=4); and biliary stricture with vascular complication (n=3). The three cases bile leakages recovered after interventional procedures. The seven biliary strictures underwent percutaneous transhepatic cholangial drainage (PTCD). All cases without vascular complications were completely cured after PTCD or a subsequent surgical re-anastomosis. In the vascular complication group, early recorrection of the HA occlusion with successful PTCD treatment were performed in two cases, but one other case with diffuse ischemic biliary destruction had a poor result. CONCLUSION: Successful interventional radiographic approaches are effective for anastomotic biliary complications but with poor results in diffuse ischemic biliary destruction.

Superparamagnectic iron oxide-enhanced magnetic resonance for tumor surveillance in cirrhotic liver before liver transplantation with explanted liver correlation.

OBJECTIVE: The aim of this study was to determine the accuracy of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) in the detection of liver tumors in patients with liver cirrhosis before liver transplantation (LT). PATIENTS AND METHODS: Twenty-one patients with moderate to severe liver cirrhoses (Child-Pugh score B or C) underwent SPIO-enhanced MRI before LT. SPIO-enhanced MRI was composed of SPIO-enhanced T1-weighted images, T2-weighted turbo spin-echo, and T2*-weighted sequences. The detection of malignant liver tumor was based on hepatic lesions that remain with hyper-signal intensity on SPIO-enhanced delayed T2 and T2*-weighted images. The imaging was compared with findings during histopathologic evaluation of the explanted liver. RESULTS: Forty-two liver nodules were found in 16 of the 21 patients. Thirty-six malignant hepatic neoplasms were detected at histopathologic evaluation. SPIO-enhanced MRI depicted 30 of 36 malignant hepatic neoplasms. Patient-based analysis showed that the sensitivity, specificity, and accuracy of MRI were 93.75%, 100%, and 95.2%, respectively. For lesion-based analysis, the sensitivity, specificity, and the area under the receiver operating characteristic (ROC) curve were 90%, 100%, and 0.95, respectively, for lesions >2 cm. CONCLUSIONS: SPIO-enhanced MRI can be used as an additional diagnostic tool for the detection and characterization of malignant tumors in cirrhotic livers. This diagnostic evaluation is accurate to triage patients for LT.

Correlation between imaging and pathologic findings in explanted livers of hepatocellular carcinoma cases.

PURPOSE: We sought investigate the accuracy of preoperative computed tomography angiography (CTA) and magnetic resonance imaging (MRI) to evaluate tumor-related prognostic factors, including tumor size, number, portal vein (PV) thrombosis, and bile duct invasion. MATERIALS AND METHODS: From March 2006 to October 2008, we enrolled 57 patients with hepatocellular carcinoma (HCC) who were undergoing liver transplantation at our institute. Imaging was performed with multidetector 64 slice CTA and MRI within 1 month preoperatively. Imaging findings including tumor size, number, PV thrombosis, and bile duct invasion were correlated with histopathologic features from the explanted livers. RESULTS: We included 128 HCCs in 57 patients in this study. The sensitivities to detect tumor number and size were 83.6% and 88.8% for CTA, and 75.8% and 88.7% for MRI. In addition, CTA and MRI were both accurate to determine whether patients were beyond or within the Milan and UCSF criteria. Fifteen patients with PV microthrombosis and 1 with bile duct microinvasion were not found on CTA or MRI preoperatively; negative predictive value of PV microthrombosis and bile duct microinvasion were 73.68% and 98.25%, respectively. During follow-up, 2 patients experienced recurrence, one of which was associated with PV microthrombosis, and 4 patients died of causes unrelated to HCC. CONCLUSION: CTA and MRI were both accurate to determine whether patients fit within the Milan or UCSF criteria, but CTA was slightly better than MRI to evaluate tumor number and size. However, pretransplant diagnostic pitfalls were PV microthrombosis and bile duct microinvasion.

Early modulation of portal graft inflow in adult living donor liver transplant recipients with high portal inflow detected by intraoperative color Doppler ultrasound.

Splenic flow clearly contributes to portal hyperperfusion in end-stage liver disease patients with hypersplenism. Early modulation of portal graft inflow can relieve the partial graft from the deleterious effects of this portal overflow. Color Doppler ultrasound may play an important role in the intraoperative detection of patients with high recipient portal inflow. Among 138 cases, portal inflow increased after liver transplantation, namely recipient portal inflow (rPVF) of 60 to 554 mL/min/100 g graft weight (mean=156 mL/min/100 g). There were eight cases in which the rPVF was >250 mL/min/100 g graft weight. In the early period of this study, there were two patients with high portal inflow (rPVF>250 mL/min/100 g graft) who did not undergo modulation of the portal flow. Small-for-size syndrome occurred in two patients. Later in the series, six patients underwent intraoperative splenic arterial ligation or splenectomy; only one of them displayed prolonged hyperbilirubinemia. The incidence of small-for-size syndrome between these two groups was significant (P=.048). No complication occurred related to the splenic artery ligation or the splenectomy. In conclusion, early modulation of portal graft inflow can protect the graft from portal overflow damage. Intraoperative Doppler ultrasound measurement is an optimal modality for detection of high rPVF.

Does hepatic graft weight affect the reduction of spleen size after living donor liver transplantation?

OBJECTIVE: Our aim was to evaluate whether the reduction in spleen volume at 6 months after living donor liver transplantation (LDLT) was affected by the size of the right lobe liver graft. PATIENTS AND METHODS: We analyzed 87 adult recipients of right lobe liver grafts who displayed preoperative splenomegaly: spleen volume>500 cm3 by computed tomographic (CT) volumetry. The recipients were grouped according to the graft weight-to-recipient weight ratio: GRWR>1 versus GRWR<1. The 2 groups were compared at 6 months after LDLT for mean postoperative spleen volume (SV) and mean SV change ratio 5, which was defined as [(SVpreop-SV6m)/SVpreop]x100%, where SVpreop and SV6m represent SV calculated based on CT examinations preoperatively and at 6 month follow-up after LDLT, respectively. RESULTS: The GRWR ranged from 0.77 to 1.66. There were 53 patients with GRWR>1 and 34 with GRWR<1. Our analysis showed significant hepatic graft volume regeneration and SV reduction at 6 months after LDLT. The SV change ratio weakly but significantly correlated with the transplanted liver graft weight (Pearson correlation coefficient, r=0.274; P<.009). In the group GRWR>1, the mean postoperative SV and the mean SV change ratio were 632+/-220 cm3 and decreased by 32+/-11%, respectively. The mean postoperative SV and the mean SV change ratio in group GRWR<1 were 598+/-188 cm3 and decreased by 34+/-13%, respectively. There were no differences in mean postoperative SV and mean SV change ratios between the 2 groups. CONCLUSION: LDLT using a right lobe graft resulted in a significant reduction of SV at 6 months after surgery, but there were no significant differences between recipients who received different sized right lobe liver grafts.

Vascular stents in the management of portal venous complications in living donor liver transplantation.

To evaluate the efficacy of stent placement in the treatment of portal vein (PV) stenosis or occlusion in living donor liver transplant (LDLT) recipients, 468 LDLT records were reviewed. Sixteen (10 PV occlusions and 6 stenoses) recipients (age range, 8 months-59 years) were referred for possible interventional angioplasty (dilatation and/or stent) procedures. Stent placement was attempted in all. The approaches used were percutaneous transhepatic (n = 10), percutaneous transsplenic (n = 4), and intraoperative (n = 2). Technical success was achieved in 11 of 16 patients (68.8%). The sizes of the stents used varied from 7 mm to 10 mm in diameter. In the five unsuccessful patients, long-term complete occlusion of the PV with cavernous transformation precluded catherterization. The mean follow-up was 12 months (range, 3-24). The PV stent patency rate was 90.9% (10/11). Rethrombosis and occlusion of the stent and PV occurred in a single recipient who had a cryoperserved vascular graft to reconstruct the PV during the LDLT operation. PV occlusion of >1 year with cavernous transformation seemed to be a factor causing technical failure. In conclusion, early treatment of PV stenosis and occlusion by stenting is an effective treatment in LDLT. Percutaneous transhepatic and transsplenic, and intraoperative techniques are effective approaches depending on the situation.

Liver graft regeneration in right lobe adult living donor liver transplantation.

Optimal portal flow is one of the essentials in adequate liver function, graft regeneration and outcome of the graft after right lobe adult living donor liver transplantation (ALDLT). The relations among factors that cause sufficient liver graft regeneration are still unclear. The aim of this study is to evaluate the potential predisposing factors that encourage liver graft regeneration after ALDLT. The study population consisted of right lobe ALDLT recipients from Chang Gung Memorial Hospital-Kaohsiung Medical Center, Taiwan. The records, preoperative images, postoperative Doppler ultrasound evaluation and computed tomography studies performed 6 months after transplant were reviewed. The volume of the graft 6 months after transplant divided by the standard liver volume was calculated as the regeneration ratio. The predisposing risk factors were compiled from statistical analyses and included age, recipient body weight, native liver disease, spleen size before transplant, patency of the hepatic venous graft, graft weight-to-recipient weight ratio (GRWR), posttransplant portal flow, vascular and biliary complications and rejection. One hundred forty-five recipients were enrolled in this study. The liver graft regeneration ratio was 91.2 +/- 12.6% (range, 58-151). The size of the spleen (p = 0.00015), total portal flow and GRWR (p = 0.005) were linearly correlated with the regeneration rate. Patency of the hepatic venous tributary reconstructed was positively correlated to graft regeneration and was statistically significant (p = 0.017). Splenic artery ligation was advantageous to promote liver regeneration in specific cases but splenectomy did not show any positive advantage. Spleen size is a major factor contributing to portal flow and may directly trigger regeneration after transplant. Control of sufficient portal flow and adequate hepatic outflow are important factors in graft regeneration.

Preoperative imaging evaluation of potential living liver donors: reasons for exclusion from donation in adult living donor liver transplantation.

Accurate pretransplant evaluation of a potential donor in living donor liver transplantation (LDLT) is essential in preventing postoperative liver failure and optimizing safety. The aim of this study was to investigate the reasons for exclusion from donation of potential donors in adult LDLT. From September 2003 to June 2006, 266 potential donors were evaluated for 215 recipients: 220 potential donors for 176 adult recipients; 46 for 39 pediatric recipients. Imaging modalities including Doppler ultrasound, computerized tomography (CT), and magnetic resonance (MR) angiography provided vascular evaluation and MR cholangiopancreatography to evaluate biliary anatomy. Calculation of liver volume and assessment of steatosis were performed by enhanced and nonenhanced CT, respectively. In the adult group, only 83 (37.7%) potential donors were considered suitable for LDLT. Of the 137 unsuitable potential donors, 36 (26.2%) candidates were canceled because of recipient issues that included death of 15 recipients (10.9%), main portal vein thrombosis (8%), recipient condition beyond surgery (5%), and no indication for liver transplantation due to disease improvement (2%). The remaining 101 (73.8%) candidates who were excluded included steatosis (27.7%), an inadequate remnant volume (57.4%), small-for-size graft (8.9%), HLA-homozygous donor leading to one-way donor-recipient HLA match (3%), psychosocial problems (4%), as well as variations of hepatic artery (4%), portal vein (1%), and biliary system anatomy (5%). Anatomic considerations were not the main reason for exclusion of potential donors. An inadequate remnant liver volume (< 30%) is the crucial point for the adult LDLT decision.