H.-Y. Ou

Prophylactic intraoperative uterine artery embolization to control hemorrhage in abnormal placentation during late gestation

OBJECTIVE To determine whether prophylactic intraoperative uterine artery embolization (UAE) reduces blood loss and minimizes morbidity and mortality in cases of placenta accreta, increta, and percreta. DESIGN A prospective, nonrandomized clinical trial. SETTING A university-based, high-risk pregnancy unit and department of interventional radiology. PATIENT(S) Eleven patients who were diagnosed prenatally with placenta accreta, increta, and percreta. INTERVENTION(S) Patients with suspected placenta accreta were treated with prophylactic, intraoperative UAE immediately after fetal delivery and before removal of the placenta. Patients with suspected placenta increta were treated with UAE; the placenta remained in situ, or a hysterectomy was performed. Patients with suspected placenta percreta were treated with UAE, and the placenta remained in situ. MAIN OUTCOME MEASURE(S) Intraoperative blood loss, maternal mortality, fetal mortality, need for hysterectomy. RESULT(S) Eleven viable fetuses were born with no radiation exposure. There were no maternal or fetal mortalities. Nine of 11 patients had an estimated blood loss between 500 and 2300 mL. Emergency hysterectomy was performed in two patients because of massive bleeding. The complications, including peritonitis and endometritis, occurred in another two patients after embolization. CONCLUSION(S) Prophylactic, intraoperative UAE before placental expulsion appears to reduce the risk of postpartum hemorrhage, decrease morbidity and mortality, and increase the chance of preservation of the uterus in patients with placenta accreta, increta, and percreta.

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.

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.

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.

Portal vein thrombosis in biliary atresia patients after living donor liver transplantation

BACKGROUND Vascular complications are major complications after living donor liver transplantation (LDLT), especially in biliary atresia (BA). Early diagnosis and treatment of portal vein thrombosis (PVT) may ensure optimal graft function and good recipient survival. Our aim was to find any association between pre- and post-transplant anatomic characteristics and hemodynamics, and the occurrence of post-transplant PVT in BA patients undergoing LDLT. METHODS We evaluated the pre- and post-transplant findings in ultrasonography in 105 BA recipients who underwent primary LDLT to determine the possible associated factor(s) and ultrasonographic warning sign(s) that may cause PVT development after LDLT. RESULTS There were 53 male and 52 female recipients. The mean age, height, and weight were 2.8 years, 83.6 cm, and 12.5 kg, respectively. Occlusion of the portal vein (PV) developed in 8 patients. On multivariate analysis, the only independent, pretransplant risk factor predisposing to PV occlusion post-transplant was small main PV size (P = .008). Post-transplant ultrasonographic warning signs included PV flow <10 cm/sec (P = .003), high hepatic artery flow >70 cm/sec (P = .027), and lesser hepatic artery resistance index <0.65 (P = .013). Both slow PV flow <10 cm/sec and lesser hepatic artery resistance index have high sensitivity and specificity in predicting post-LDLT PVT. CONCLUSION Small PV size (<4 mm) and slow portal flow <10 cm/sec combined with lesser hepatic artery resistance index (<0.65) are strong warning signs that may predict the development of post-LDLT PVT in BA patients that require close monitoring.

Doppler Ultrasound Evaluation of Postoperative Portal Vein Stenosis in Adult Living Donor Liver Transplantation

AIM To evaluate the postoperative portal vein stenosis (PVS) and the diagnostic efficiency of Doppler ultrasound (DUS) in adult living donor liver transplantation (ALDLT). MATERIALS AND METHOD From January 2007 to December 2008, 103 ALDLTs were performed and postoperatively followed by routine DUS. The morphologic narrowing at the anastomotic site (AS) of the PVS was analyzed. We calculated the PV stenotic ratio (SR) using the following formula: SR (%)=PRE-AS/PRE (PRE=pre-stenotic caliber). An SR>50% was defined as the critical point for PVS. We also calculated the velocity ratio (VR) between the AS and PRE, and set the significant VR as >3:1. Statistical analyses were carried out to determine clinical significance. RESULTS Using the definition of morphologic PVS by DUS, there were total 20 cases (19.4%) in this series with SR>50%, which included 17 cases with VR>3:1. Eight cases of severe PVS had a stenotic AS>5 mm and subsequently underwent interventional management. Doppler criteria of SR and VR values were elevated up to 75.8% and 7.5:1, respectively, in these treated cases. Two cases of severe PVS subsequently developed PV thrombosis. Intervention by balloon dilation and/or stenting was performed successfully in this PVS case. CONCLUSION DUS is the most convenient and efficient imaging modality to detect and follow postoperative PVS in ALDLT. The Doppler criteria of SR and VR are both sensitive but less specific. Cases of AS<5 mm require interventional management for good long-term graft survival.

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.

Interventional Percutaneous Trans-Splenic Approach in the Management of Portal Venous Occlusion After Living Donor Liver Transplantation

A 2-year-old Chinese boy with progressive familial intrahepatic cholestasis type II–related end-stage liver disease underwent living donor liver transplantation (LDLT) using a left lateral segment graft from his mother. Preoperative computed tomography angiography showed that the hepatic artery, inferior vena cava, and portal vein were patent. The left portal vein of the graft was connected to the recipient’s right anterior portal vein. The left hepatic vein of the graft was connected to the recipient’s hepatic veins with triple venoplasty. The left hepatic artery of the graft was connected to the recipient’s right hepatic artery. The left hepatic duct of the graft was connected to the recipient’s common hepatic duct with a microsurgical technique. After the operation, the infant underwent reworking of the hepatic artery anastomosis twice because of early hepatic artery thrombosis. He also underwent revision of the biliary reconstruction to Roux-en-Y hepaticojejunostomy because of biliary anastomotic stricture. At 18 months post-transplant, there was poor visualization of the intrahepatic portal vein, but there was hepatofugal flow inside the left portal vein during Doppler ultrasound follow-up studies. Splenomegaly and minimal ascites were also noted by ultrasound. The computed tomography angiography study showed mild intrahepatic bile duct dilatation, marked splenomegaly, and occlusion of the transverse portion of the portal vein with collateral vessels also noted. The patient was subsequently referred for a possible interventional radiological procedure as initial management for the occluded portal vein. The patient underwent vascular catheter intervention under general anesthesia. The percutaneous transsplenic approach was performed to puncture the splenic vein with a 21-gauge Chiba needle (Cook, Bloomington, IN) under ultrasonographic and fluoroscopic guidance. The needle was changed to a 4-French coaxial dilator and a 7-French sheath (Terumo, Tokyo, Japan) over a 0.035inch angled hydrophilic guide wire (Terumo) after confirmation that the needle was in the splenic vein. Direct main portal venography and the pressure gradient across the stenosis were then obtained. Portography showed total occlusion of the portal vein at its umbilical portion (Fig. 1). The coronary vein was prominent, and gastroesophageal varices were also noted. The extrahepatic portal pressure was 18 mm Hg, and the intrahepatic portal pressure was 18 mm Hg. Hence, there was no pressure gradient across the area of stenosis. A 0.035-inch guide wire and a 4-French J curve catheter (Terumo) were used to traverse the area of portal vein stenosis (Fig. 2). A wall stent (9.0 mm 5.0 cm; Boston Scientific, Natick, MA) was placed to bypass the area of stenosis from the umbilical portion up to the visualized segment 3 portal vein. A second similarly sized wall stent was placed from the mid portion of the native main portal vein to the splenic vein. Balloon angioplasty (6.0-40 mm, 80 cm; Wanda, Bos-

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.

Regeneration and outcome of dual grafts in living donor liver transplantation

In living donor liver transplantation (LDLT), the essential aims are to provide an adequate graft volume to the recipient and to keep a sufficient remnant liver volume in the donor. In some instances, these aims cannot be met by a single donor and LDLT using dual grafts from two donors is a good solution. From 2002 to 2009, five recipients in our hospital received dual graft LDLT. Two recipients received one right lobe and one left lobe grafts; the other three received two left lobe grafts. The mean final liver regeneration rate was 91.2%. Left lobe graft atrophy in the long term was observed in recipients who received a right and a left lobe grafts. The initial bigger volume graft in all recipients was noted to have better regeneration than the smaller volume grafts. Portal flow and bilateral grafts volume size discrepancy were considered as two major factors influencing graft regeneration in this study. We also noted that the initial graft volume correlated with portal flow in the separate grafts and finally contribute to individual graft regeneration. Because of compensatory hypertrophy of the other graft, recipients who experienced atrophy of one graft did not show signs of liver dysfunction.