The safety of tranexamic acid administration in total knee arthroplasty: a population-based study from Taiwan.

Tranexamic acid is an effective treatment to reduce blood loss. We performed a retrospective observational study to evaluate safety in unilateral total knee arthroplasty. We utilised Taiwan's national health insurance database to identify relevant patients and to retrieve information on peri-operative blood transfusions and tranexamic acid administration within 60 days of follow-up. We examined changes in the rate of transfusions and adverse events with respect to tranexamic acid administration using logistic regression. We observed a total of 226,719 knee arthroplasty cases during 2010-2019. Transfusion and tranexamic acid administration rates were 38.9% (88,258) and 42.9% (97,237), respectively. Tranexamic acid was associated with a 50% decrease in blood transfusions (RR: 0.50, 95%CI: 0.48-0.51). After propensity-score matching, tranexamic acid was not associated with pulmonary embolism; deep vein thromboembolism; artery vein thromboembolism; acute myocardial infarction; ischaemic stroke; or in-hospital mortality, but was significantly associated with acute kidney injury. Patients with existing chronic kidney disease suffered a high absolute risk of kidney injury irrespective of tranexamic acid administration (832 per 10,000, 95%CI 797-869). Tranexamic acid was also associated with surgical site infection. There was strong interaction between blood transfusion; tranexamic aid administration; and development of surgical site infection. In conclusion, tranexamic acid use was associated with decreased blood transfusion and was not associated with thromboembolic events. However, careful consideration is required before use in patients with pre-existing renal disease. Further, our observed interaction between patients given tranexamic acid who subsequently require transfusion requires careful consideration with respect to enhanced prophylaxis against surgical site infection.

Close Cassini flybys of Saturn's ring moons Pan, Daphnis, Atlas, Pandora, and Epimetheus.

Saturn's main ring system is associated with a set of small moons that either are embedded within it or interact with the rings to alter their shape and composition. Five close flybys of the moons Pan, Daphnis, Atlas, Pandora, and Epimetheus were performed between December 2016 and April 2017 during the ring-grazing orbits of the Cassini mission. Data on the moons' morphology, structure, particle environment, and composition were returned, along with images in the ultraviolet and thermal infrared. We find that the optical properties of the moons' surfaces are determined by two competing processes: contamination by a red material formed in Saturn's main ring system and accretion of bright icy particles or water vapor from volcanic plumes originating on the moon Enceladus.

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.

Acoustic Radiation Force Impulse Elastography in Post-transplant Recurrent Hepatitis C in Living Donor Liver Transplantation.

OBJECTIVE: The aim of the study was to evaluate the efficacy of liver fibrosis (LF) with acoustic radiation force impulse (ARFI) elastography for post-transplant (post-LT) HCV recurrence. PATIENTS AND METHODS: We enrolled 89 adult recipients of living donor liver transplantation (LDLT) who had HCV, with or without post-LT HCV recurrence and treated or not treated. The post-LT HCV recurrence was diagnosed on the basis of RNA viral load present. ARFI examination was performed every 3 months for all patients, with shear wave velocity (SWV) obtained quantitatively in m/s and correlated with histopathologic fibrosis scoring of liver biopsy (LB). RESULTS: There were 50 (50 of 89) patients without HCV recurrence and 39 (39 of 89) with post-LT recurrence in the 89 patients studied. The recurrent group had significantly higher median SWVs (1.87 ± 0.52 vs 1.37 ± 0.52 m/s, P < .0001), in which 18 (18 of 39) patients had antiviral drug treatment and obtained significant improvement with SWVs from 1.83 ± 0.49 to 1.68 ± 0.56 m/s, P = .043. The correlations of LF staging between ARFI elastography and Ishak histopathologic LF scores showed great significance, P = .045. The HCV RNA titer after antiviral treatment decreased from 3,831,750 to 0, P < .0001, but the RNA titer of nontreated patients remained high and the median SWV increased. The Ishak LF staging in the nontreated group progressed from stage 1 to 2, P = .012 and SWV increased from 1.69 ± 0.54 to 1.91 ± 0.66 m/s, P = .085 at 1-year follow-up. CONCLUSION: ARFI elastography has efficient quantitative LF monitoring correlated with histopathologic staging for post-LT HCV recurrence. It could be an alternative, noninvasive method for frequent LB in the disease follow-up.

Efficiency of Transluminal Angioplasty of Hepatic Venous Outflow Obstruction in Pediatric Liver Transplantation.

BACKGROUND: Our aim in this study was to evaluate long-term efficiency of hepatic venous balloon angioplasty (BA) and stent placement (SP) for hepatic venous outflow obstruction (HVOO) in pediatric liver transplantation (LT). METHODS: From January 1999 to September 2016, 262 pediatric patients underwent LT at our hospital. Ten were diagnosed with HVOO, which included 8 living donor grafts and 2 split liver grafts. BA and SP were used in management of these 10 patients with HVOO. After intervention, Doppler ultrasound (DUS) was the major follow-up modality for comparing efficiency of BA and SP. RESULTS: The incidence of HVOO was 3.8% (10 of 262) in our pediatric LTs. Of the 10 HVOO cases, 5 had SP, 3 had BA once, 1 had BA twice, and 1 had BA twice along with SP. The patent hepatic vein was maintained after a mean follow-up of 7.4 (range, 0.04-17) years. Recurrent rate of HVOO after BA was 42%. Neither recurrent HVOO nor stent migration occurred after SP and throughout long-term follow-up. CONCLUSION: Hepatic venous SP was found to be more effective and safe than BA for treatment of HVOO in pediatric LT for long-term follow-up.

Dust grains fall from Saturn's D-ring into its equatorial upper atmosphere.

The sizes of Saturn's ring particles range from meters (boulders) to nanometers (dust). Determination of the rings' ages depends on loss processes, including the transport of dust into Saturn's atmosphere. During the Grand Finale orbits of the Cassini spacecraft, its instruments measured tiny dust grains that compose the innermost D-ring of Saturn. The nanometer-sized dust experiences collisions with exospheric (upper atmosphere) hydrogen and molecular hydrogen, which forces it to fall from the ring into the ionosphere and lower atmosphere. We used the Magnetospheric Imaging Instrument to detect and characterize this dust transport and also found that diffusion dominates above and near the altitude of peak ionospheric density. This mechanism results in a mass deposition into the equatorial atmosphere of ~5 kilograms per second, constraining the age of the D-ring.

Donor Outcomes After Liver Donation in Adult to Adult Living Donor Liver Transplantation.

OBJECTIVES: This study aims to investigate postdonation outcomes of adult living donor liver transplantation donors and remnant liver regeneration in different graft types. METHODS: A total of 236 adult living donor liver transplantation donors were classified into different groups: donors with <35% remnant liver volume (group A; n = 56) and donors with remnant liver volume ≥35% (group B, n = 180); left lobe grafts (LLG group; n = 98) including middle hepatic vein (MHV) and right lobe grafts (RLG group; n = 138) without MHV. The 98 LLG group donors were further classified into 2 subgroups based on hepatic venous drainage patterns: MHV-dominant (n = 20) and non-MHV-dominant (n = 78). The demographic data, postoperative laboratory data, complications, graft weight, remnant liver volume, remnant liver growth rate, and remnant liver regeneration rate (RLRR) after partial liver donation were analyzed. RESULTS: The postoperative aspartate aminotransferase, alanine aminotransferase, total bilirubin, intensive care unit stays, and hospitalization stays were higher in A and RLG group donors. All the donor complications in our series were minor complications. The postoperative complication rate was higher in the A and RLG group, but failed to reach statistical significance. There was no significant difference in RLRR between the RLG/LLG and A/B groups. However, the MHV-dominant group had significantly lower RLRR than the non-MHV-dominant group (P < .05). CONCLUSIONS: Small remnant liver volume donors (<35% remnant liver) have higher risks of developing postdonation minor complications. Left lobe liver donation in MHV-dominant donor candidates are a major concern.

Chemotherapy and radiation components of neoadjuvant treatment of pancreatic head adenocarcinoma: Impact on perioperative mortality and long-term survival.

BACKGROUND: We compared outcomes of neoadjuvant therapy delivered as chemotherapy-only (Chemo) versus concurrent chemoradiation (ChemoRT) versus chemotherapy followed by radiation (Chemo-ChemoRT) among pancreatic head adenocarcinoma patients receiving pancreaticoduodenectomy. METHODS: National Cancer Data Base cases diagnosed 2006-2011 treated by neoadjuvant therapy and pancreaticoduodenectomy. RESULTS: 1163 pts received neoadjuvant treatment with Chemo (n = 309; 26.6%), ChemoRT (n = 626; 53.8%), or Chemo-ChemoRT (n = 228; 19.6%). Odds of 30-day and 90-day mortality were not influenced by delivery of any neoadjuvant therapy type. Median overall survival for Chemo, ChemoRT, and Chemo-ChemoRT groups were 25.6 (95% confidence interval 23.1-28.7), 22.9 (21.4-24.8), and 26.9 (23.7-29.4) months, respectively. There was no statistically significant difference between Chemo and Chemo-ChemoRT groups (log rank test p = 0.854), while there was significant difference of ChemoRT (p = 0.017 versus Chemo; p = 0.021 versus Chemo-ChemoRT). Multivariate model suggests delivery of concurrent ChemoRT as opposed to neoadjuvant therapy with full dose systemic chemotherapy is associated with shortened survival (aHR = 1.311, p = 0.001). CONCLUSIONS: There is no detectable difference in early outcomes (30-day and 90-day postsurgical mortality) among pancreaticoduodenectomy patients treated with various types of neoadjuvant therapy. Overall survival appears better among patients exposed preoperatively to full dose systemic chemotherapy rather than concurrent chemoradiation only. Further studies with more detailed data sources are needed.

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.

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.

Drug-Eluting Bead Transarterial Chemoembolization as Bridge Therapy for Hepatocellular Carcinoma Before Living-Donor Liver Transplantation.

BACKGROUND: The majority of hepatocellular carcinoma (HCC) patients is diagnosed in late stages and therefore becomes ineligible for potentially curative treatment such as resection or liver transplantation. Transarterial chemoembolization (TACE) with drug-eluting beads (DC beads, Biocompatibles, Farnham, United Kingdom) has been proven with less side effects and better efficacy than conventional TACE, especially among patients with poor liver function. PURPOSE: The aim of this study is to evaluate outcomes of HCC patients who received TACE with DC beads, which resulted to eligibility for liver transplantation. METHODS AND MATERIALS: From January 2012 to June 2015, 60 patients with HCC received pre-liver transplantation evaluation whose cases were managed with TACE using DC beads at Kaohsiung Chang Gung Memorial Hospital were included in the study. DC beads loaded with doxorubicin were used. RESULTS: Forty percent of the patients had complete tumor response. Thirty-three percent of the patients had partial tumor response, of which 15% showed stable disease, 11.7% exhibited disease progression including 3 with portal vein thrombosis, 1 with both hepatic vein and portal vein thrombosis, and 3 with increase in tumor size. Twenty-three patients were beyond University of California, San Francisco (UCSF) criteria initially. The successful downstage rate was 73.9% (17 of 23). Thirty-seven patients fit the USCF criteria initially. The 3-, 6- and 12-month drop rates of these patients were 0%, 3.9%, and 16.8%, respectively. Twenty-four (40%) patients successfully underwent liver transplantation. Three patients (12.5%) demonstrated recurrent HCC after liver transplantation. CONCLUSION: TACE with DC bead can effectively induce tumor necrosis and appears to be a successful approach as bridge therapy for patients with advanced HCC and poor liver function.

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.

Sonographic Evaluation of Post-transplantation Portal Vein Stenosis in Pediatric Living-donor Liver Transplant Recipients With Left-liver Grafts.

INTRODUCTION: Portal vein (PV) stenosis is not uncommon in post-transplantation pediatric living-donor liver transplant (PLDLT) recipients. The purpose of this study was to identify specific ultrasound criteria that may be used to detect PV stenosis in PLDLT with left-liver grafts. PATIENTS AND METHODS: From January 2010 to October 2014, 87 pediatric recipients underwent PLDLT with left lobes or left lateral segments at our hospital. All patients underwent routine liver Doppler ultrasound (DUS) as follow-up protocol. The morphologic narrowing and mean time averaged velocity (TAV) at the PV anastomotic site, change in anastomotic/pre-anastomotic TAV (ΔTAV), and the umbilical portal width were evaluated and analyzed. Ultrasound findings were correlated with computed tomography angiography where PV stenosis was suspected. RESULTS: In the liver graft follow-up study, 80.4% (70 of 87 patients) of PV anastomosis was well visualized and measured by Doppler ultrasound. The optimal threshold values for TAV and ΔTAV were 49.6 cm/s and 30 cm/s, respectively, for significant PV anastomosis stenosis. In the other 19.5% (17/87), the PV anastomosis could not be identified properly. The PV anastomosis was not always visible with ultrasound; however, the optimal dilated umbilical portion of the PV indicating possible PV anastomosis narrowing threshold was umbilical portal width >1.5 cm. CONCLUSIONS: Increased anastomotic TAV and ΔTAV are useful features for diagnosing PV stenosis. The identification of a dilated umbilical portion of the left PV helps in detection of PV stenosis in PLDLT recipients especially when the anastomotic narrowed region cannot be visualized.

Flux and composition of interstellar dust at Saturn from Cassini's Cosmic Dust Analyzer.

Interstellar dust (ISD) is the condensed phase of the interstellar medium. In situ data from the Cosmic Dust Analyzer on board the Cassini spacecraft reveal that the Saturnian system is passed by ISD grains from our immediate interstellar neighborhood, the local interstellar cloud. We determine the mass distribution of 36 interstellar grains, their elemental composition, and a lower limit for the ISD flux at Saturn. Mass spectra and grain dynamics suggest the presence of magnesium-rich grains of silicate and oxide composition, partly with iron inclusions. Major rock-forming elements (magnesium, silicon, iron, and calcium) are present in cosmic abundances, with only small grain-to-grain variations, but sulfur and carbon are depleted. The ISD grains in the solar neighborhood appear to be homogenized, likely by repeated processing in the interstellar medium.

Genome-wide normalized score: a novel algorithm to detect fetal trisomy 21 during non-invasive prenatal testing.

OBJECTIVES: Non-invasive prenatal testing for fetal trisomy 21 (T21) by massively parallel shotgun sequencing (MPSS) is available for clinical use but its efficacy is limited by several factors, e.g. the proportion of cell-free fetal DNA in maternal plasma and sequencing depth. Existing algorithms discard DNA reads from the chromosomes for which testing is not being performed (i.e. those other than chromosome 21) and are thus more susceptible to diluted fetal DNA and limited sequencing depth. We aimed to describe and evaluate a novel algorithm for aneuploidy detection (genome-wide normalized score (GWNS)), which normalizes read counts by the proportions of DNA fragments from chromosome 21 in normal controls. METHODS: We assessed the GWNS approach by comparison with two existing algorithms, i.e. Z-score and normalized chromosome value (NCV), using theoretical approximations and computer simulations in a set of 86 cases (64 euploid and 22 T21 cases). We then validated GWNS by studying an expanded set of clinical samples (n = 208). Finally, dilution experiments were undertaken to compare performance of the three algorithms (Z-score, NCV, GWNS) when fetal DNA concentration was low. RESULTS: At fixed levels of significance and power, GWNS required a smaller fetal DNA proportion and fewer total MPSS reads compared to Z-score or NCV. In dilution experiments, GWNS also outperformed the other two methods by reaching the correct diagnosis with the lowest range of fetal DNA concentrations (GWNS, 3.83-4.75%; Z-score, 4.75-5.22%; NCV, 6.47-8.58%). CONCLUSION: Our results demonstrate that GWNS is comparable to Z-score and NCV methods regarding the performance of detecting fetal T21. Dilution experiments suggest that GWNS may perform better than the other methods when fetal fraction is low.

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.