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Y F Cheng

Publications and source records attributed to Y F Cheng.

At least 19 recordsLinked to original sources
PubMed2006

Liver graft-to-recipient spleen size ratio as a novel predictor of portal hyperperfusion syndrome in living donor liver transplantation.

Portal hyperperfusion in a small-size liver graft is one cause of posttransplant graft dysfunction. We retrospectively analyzed the potential risk factors predicting the development of portal hyperperfusion in 43 adult living donor liver transplantation recipients. The following were evaluated: age, body weight, native liver disease, spleen size, graft size, graft-to-recipient weight ratio (GRWR), total portal flow, recipient portal venous flow per 100 g graft weight (RPVF), graft-to-recipient spleen size ratio (GRSSR) and portosystemic shunting. Spleen size was directly proportional to the total portal flow (p = 0.001) and RPVF (p = 0.014). Graft hyperperfusion (RPVF flow > 250 mL/min/100 g graft) was seen in eight recipients. If the GRSSR was < 0.6, 5 of 11 cases were found to have graft hyperperfusion (p = 0.017). The presence of portosystemic shunting was significant in decreasing excessive RPVF (p = 0.059). A decrease in portal flow in the hyperperfused grafts was achieved by intraoperative splenic artery ligation or splenectomy. Spleen size is a major factor contributing to portal flow after transplant. The GRSSR is associated with posttransplant graft hyperperfusion at a ratio of < 0.6.

Adolescent↗
PubMed2005

The significance of hepatic vein outflow volume in hepatic outflow insufficiency of living right liver graft evaluated by Doppler ultrasound.

The color Doppler ultrasound has been used to evaluate hepatic vein (HV) outflow insufficiency based on flow velocity and waveforms. In our experience, some cases with flat waveforms are clinically asymptomatic. The parameters of HV flow velocity and waveforms are not always correlated with clinical problems. So, we proposed that total HV flow volume (HVFV) may be a more reliable index. From August 2001 to July 2003, 31 cases among 48 adult-to-adult living related transplants of a right liver graft had one HV anastomosis. HV velocity, waveforms, and HVFV were compared both before and after transplantation. We set the minimal HVFV ratio at 80% based on the original HVFV before graft retrieval. There was no significant difference in HVFV before liver graft retrieval between the 2 groups, but there was a significant change after transplantation. There were no cases of HV insufficiency among group A patients (>80%), whose HVFV ranged from 397 to 1181 mL/min with ratios from 75% to 180% (mean 115%). In group B, there were 4 complicated cases with prolonged severe ascites (<80%) with HVFV ratios from 56% to 76% (mean 66%). Fisher exact test showed a great significance (P < .001). Thus the preliminary criteria of 80% minimal HVFV ratio allows detection of HV insufficiency for further interventional management.

Adult↗
PubMed2004

Hepatic venous stenosis in partial liver graft transplantation detected by color Doppler ultrasound before and after radiological interventional management.

Hepatic outflow insufficiency remains one of the major complications causing postoperative graft failure especially among partial liver graft transplantations (PLT) including living donor liver transplantation (LDLT), reduced size liver transplantation (RLT), and split liver transplantation (SLT). These procedures are different from the whole liver graft transplantations (OLT), which include multiple vascular anastomoses. Color Doppler ultrasound (CDUS) was used to evaluate the hepatic venous outflow from grafts before and after radiological interventional management and to document treatment effects. From June 1994 to March 2003, our 136 cases of PLTs included 131 LDLTs, two RLTs, and three SLTs. Seven cases (six children and one adult) showed postoperative hepatic vein outflow obstruction and persistent massive ascites, as detected by color Doppler ultrasound (CDUS) and confirmed by interventional angiography. The CDUS showed a monophasic flat waveform with a relatively low hepatic vein average peak velocity (Va) in all cases (mean 11 cm/s). Successful interventional procedures included balloon dilatation in three cases and metallic stent replacement in four cases. CDUS was used with guidance during the procedure to confirm restoration of normal hepatic vein flow with a multiphasic waveform and an objective increase of average flow velocity (high to average 66 cm/s). Ascites disappeared dramatically after the procedure. In conclusion CDUS is the prime modality to diagnose and document a treatment response.

Adult↗
PubMed2004

The significance of transarterial embolization for advanced hepatocellular carcinoma in liver transplantation.

INTRODUCTION: Transarterial embolization (TAE) is the treatment of choice for advanced HCC to control or even induce tumor shrinkage. The aim of this study was to evaluate the effect of pretransplantation TAE for treatment of advanced HCC. MATERIAL AND METHODS: From 1996 to 2002, we studied 12 cirrhotic patients with HCC, including six who met and six who exceeded the Milan criteria. All patients had sufficient hepatic function to undergo TAE. Liver transplantations were performed subsequently and they were followed prospectively for a median of 22 months (range = 12 to 53 months). RESULTS: The explanted livers from the 12 patients who had undergone TAE were noted to have extensive tumor necrosis. The pathological specimens at LT showed downstaging of the HCC, which allowed those six patients to meet the Milan criteria. The overall 1- and 2-year survival rates were 92% and 73%, respectively. The overall 1- and 2-year disease-free survival rates were 92% and 73%, respectively. One death unrelated to liver disease at 2 years after LT was noted in the downgraded group. One patient of the initially eligible group developed lung metastasis at 6 months and died at 12 months after LT. CONCLUSION: TAE is effective to downstage advanced HCC and reduce the dropout rate on the LT waiting list. Pre-LT TAE may be considered as a better therapeutic strategy for patients with advanced HCC.

Carcinoma, Hepatocellular↗
PubMed2004

Hypercalcaemia and haemophagocytic syndrome: rare concurrent presentations of disseminated tuberculosis in a dialysis patient.

Tuberculosis remains an important cause of infection in chronic haemodialysis patients. Frequent extrapulmonary involvement, non-specific presentation and limited diagnostic tools usually make early diagnosis difficult. Herein, we report on an 83-year-old female patient who had been on regular heamodialysis therapy for 15 years, who presented with asymptomatic hypercalcaemia and pancytopenia. Haemophagocytic syndrome was documented during the admission period. Mycobacterium tuberculosis was cultured from bone marrow 1 month after her demise. This case report highlights the non-specific manifestations of extrapulmonary tuberculosis in dialysis patients and the limited value of conventional diagnostic methods. We would like to recommend aggressive intervention and early tissue aspiration from possible infectious sites when tuberculosis cannot be completely ruled out. Disseminated tuberculosis should be considered as an indication of hypercalcaemia where haemophagocytic syndrome occurs simultaneously.

Aged↗
PubMed2001

Single imaging modality evaluation of living donors in liver transplantation: magnetic resonance imaging.

BACKGROUND: Liver graft size, anatomy of the bile duct and the vascular inflow and outflow are essential for living related liver transplantation (LRLT). Preoperative delineation of those variations that would change the operative procedure to achieve a successful result especially in an emergency condition. PURPOSE: Our aim was to develop a rapid and noninvasive imaging diagnostic method for the detection of anatomical variants that is mandatory for a safe operation when selecting potential liver transplant living donors. We used a different magnetic resonance (MR) imaging technique, which enabled to us to exploit the anatomical landmark of the liver, signal enhancement of blood flow in the abdomen, and the intrahepatic biliary routes inside the liver. Then, with the help of Advantage Window workstation reconstruction, the reconstructed single vascular or biliary systems were displaced in a three-dimensional fashion and the whole examination finished within 30 min. METHODS: Modification of the standard MR technique was performed on a superconductive 1.5T whole body image scanner, MR arteriogaphy, venography, and cholangiography with three-dimensional reconstruction in evaluating the anatomy of the hepatic arteries, hepatic veins, portal venous system, bile ducts, and liver size in potential liver transplant living donors. These anatomical structures were compared with traditional imaging methods. RESULTS: In all 38 cases, as well as delineation of the portal vein detail to the segmental level was satisfactorily obtained in this MR study. The images were well displayed in a three-dimensional fashion, which had good correlation with images from traditional imaging modalities and operative findings. In 86.8% cases, the MR arteriography was well matched with the celiac angiography. Of those 17 operative cases, estimation of liver volume was well correlated with the liver graft within 3.9-12.5% variation. In the major hepatic vein, we obtained 100% accuracy and 88.2% in the minor branches. Of 12 donors received intraoperative cholangiography during liver donation, good correlation of biliary anatomy was achieved. One donor was excluded from graft donation due to the complicated arterial supply to the left liver. According to the anatomical variation, surgical procedures in graft harvesting and anastomosis were readjusted and no major complications were found in those donors and all recipients survived after liver transplantation. CONCLUSION: MR volumetry, venography, angiography, and cholangiography with three-dimensional reconstruction is sufficient for all major imaging evaluation. It may replace the traditional conventional catheter angiography, computed tomography, sonography and endoscopic retrograde cholangiography as a single investigation in the evaluation of the potential liver transplant donors. Angiography is only valuable in suboptimal cases and intraoperative cholangiography is only performed in biliary ductile variants.

Adult↗
PubMed2001

Dependence of reversed-phase retention of ionizable analytes on pH, concentration of organic solvent and silanol activity.

In reversed-phase chromatography, the retention of ionizable analytes is influenced by the ionic properties of the packing caused by surface silanol groups. We have measured the ion-exchange properties of both reversed-phase bonded phases and their underlying base materials. The probe used in this part of the study was bretylium tosylate. The acquired knowledge is then used for a complete and quantitative understanding of the retention behavior of ionizable compounds as a function of the pH of the mobile phase and the solvent composition. We have studied the retention pattern of a broad range of acids, bases, and polyfunctional analytes over the pH range from 2 to 11 and from water to 80% acetonitrile. A few application examples demonstrate the relevant findings.

Hydrogen-Ion Concentration↗
PubMed2001

Assessment of donor fatty livers for liver transplantation.

AIM: The effect of fatty liver on graft survival, especially with reference to macrovesicular and microvesicular steatosis, is still uncertain. This preliminarily study was designed to create a noninvasive method for the quantification of the hepatic fat content in vivo and to establish provisional criteria for the assessment of fatty donor livers before liver transplantation among transplant surgeons, radiologists, and pathologists. METHODS AND MATERIALS: Different degrees of rat fatty liver model were established by feeding rats a diet deficient in choline and methionine for different periods of time. Computed tomography (CT) with test tubes containing variable percentages of fat equivalent substance were used to assess the severity of fatty change of the rat liver. This was then correlated with the histological classification, level of hepatic enzymes, and graft survival. RESULTS: Linear correlation between the fat volume fraction added to the test tubes and CT density were found. The process of producing a fatty liver via diet alteration peaked at week 3. At this time hepatic enzymes, radiological fat content, and posttransplantation survival were worse (P=0.013), compared with other time points. Radiological assessment of fatty liver correlated well with survival and serum glutamic oxaloacetic transaminase and glutamic pyruvate transaminase levels. CONCLUSION: Severe microvesicular steatosis does not influence recipient survival, however, macrovesicular steatosis affects graft survival. Caliber CT is a practical and simple method that allows an accurate noninvasive quantitative assessment of hepatic fatty infiltration. It has potential to be a useful parameter for the assessment of donor livers for clinical liver transplantation.

Animals↗
PubMed2001

Interventional radiologic procedures in liver transplantation.

Postoperative biliary and vascular complications contribute significantly to morbidity and mortality in liver transplantation. Interventional radiologists are an integral part of the multidisciplinary team necessary for optimizing the management of these complications. During a 15-year period, 39 cadaveric and 25 living related liver transplantations were performed at the Chang Gung Memorial hospital, Taiwan. Of 64 liver transplant recipients, 9 (3 adult and 6 pediatric) underwent 13 interventional radiological procedures for the treatment of biliary sludge-casts (n = 2), bile duct occlusion or stenosis (n = 2), hepatic veins thrombosis (n = 1), hepatic veins stenosis (n = 1), portal vein stenosis with splenorenal shunting (n = 1), biloma (n = 1), and infected fluid collection or ascites (n = 4). Antegrade or retrograde interventional approach was used to successfully treat all biliary complications, and all percutaneous drainage procedures were effective in the control of intra-abdominal fluid collections. Portal vein stenosis was treated by balloon dilatation, and the associated splenorenal shunt was closed by metallic coil embolization via transhepatic catheterization of the portal vein. Hepatic vein stenosis was effectively treated by balloon dilatation and expandable metallic stent deployment via transfemoral and jugular venous approaches, respectively. Hepatic vein thrombosis was only partially lysed by transvenous streptokinase administration, and surgical thrombectomy was needed to achieve complete recanalization. The total success rate of the interventional procedures was 92 % with no procedure-related complications. The overall survival rate in this series is 89 %, and all patients who underwent living related liver transplantation maintain to date a 100 % survival rate. We can conclude that interventional radiological procedures are very useful for managing biliary and vascular complications after liver transplantation. These techniques provide a cure in most situations, thus obviating the need for further surgical intervention or re-transplantation.

Adolescent↗
PubMed2001

Spontaneous rupture of hepatocellular carcinoma during pregnancy.

BACKGROUND: Hepatocellular carcinoma associated with pregnancy is unusual. CASE: A 33-year-old woman presented at 25 weeks' gestation with sudden, severe epigastric pain for 6 hours. Abdominal ultrasonography and magnetic resonance imaging showed multiple liver tumors with a small amount of ascites. Exploratory laparotomy revealed an unresectable ruptured liver tumor that was treated by packing. Although a biopsy was nondiagnostic, ultrasound-guided needle biopsy 6 days after cesarean delivery at 41 weeks' gestation showed hepatocellular carcinoma, which was treated with transarterial embolization. At 3.5 years posttherapy, both mother and infant are well. CONCLUSION: Ruptured hepatocellular carcinoma during pregnancy is rare but should be included in the differential diagnosis of sudden, severe epigastric pain.

Abdomen, Acute↗
PubMed2001

Static wrist position associated with least median nerve compression: sonographic evaluation.

OBJECTIVE: To determine the wrist angle that produces the least compression to the median nerve and to evaluate the usefulness of sonography in determining the optimal position. DESIGN: Seventeen wrists of 17 healthy volunteers received dynamic, high-frequency (8 MHz), high-resolution sonography with the wrist splinted at various positions: 15 degrees of flexion, neutral position, and 15 degrees and 30 degrees of extension. The morphologic changes of the median nerve were evaluated with the wrist positioned at various angles. RESULTS: The neutral position caused significantly lower compression of the median nerve than it did in the other positions. However, in some cases, the lowest pressure was found when the wrist was fixed in 15 degrees of flexion or 15 degrees of extension. Because median nerve compression may decrease the anteroposterior diameter, increase the transverse diameter, and decrease the cross-sectional area, greater anteroposterior diameter, lower flattening ratio (transverse diameter/anteroposterior diameter), and greater cross-sectional area were considered to indicate lower median nerve compression. CONCLUSIONS: Neutral position of the wrist is the best position with the least median nerve compression in most individuals. However, the optimal position may vary from person to person. Sonographic examination can help to determine the splint position that results in the lowest median nerve compression.

Adult↗
PubMed2001

Tolerability and pharmacokinetics of the nitrone NXY-059 in patients with acute stroke.

BACKGROUND AND PURPOSE: Increased free radical formation contributes to the damage caused to the brain by acute ischemia. NXY-059 is a nitrone-based free radical trapping agent in development for acute stroke. NXY-059 has neuroprotective efficacy when given 5 hours after onset of transient focal ischemia in the rat. METHODS: This was a randomized, double-blind, placebo-controlled, parallel group, multicenter study that evaluated the safety and tolerability of 2 NXY-059 dosing regimens compared with placebo within 24 hours of acute stroke. NXY-059 was administered as either 250 mg over 1 hour followed by 85 mg/h for 71 hours or 500 mg over 1 hour followed by 170 mg/h for 71 hours; plasma concentrations were monitored. Neurological and functional outcomes were recorded up to 30 days. RESULTS: One hundred fifty patients were recruited, of whom 147 received study treatments and completed assessments (50 placebo, 48 lower-dose NXY-059, 49 higher-dose NXY-059). Mean (+/-SD) age was 68 (+/-10) years, and baseline National Institutes of Health Stroke Scale score was 7.9 (+/-6.2). Serious adverse events occurred in 16%, 23%, and 16% of patients, respectively, with deaths in 0%, 10%, and 4%, largely following the proportions with primary intracerebral hemorrhage (6%, 16%, and 8%). Hyperglycemia, headache, and fever were common but not related to treatment. The mean unbound steady state NXY-059 plasma concentrations were 25 and 45 micromol/L, respectively. Population pharmacokinetic analysis estimated clearance to be 4.6 L/h. CONCLUSIONS: NXY-059 was well tolerated in patients with an acute stroke. The testing of higher doses in future trials may be justified.

Adult↗