The Effect of Doppler Ultrasound on Early Vascular Interventions and Clinical Outcomes After Liver Transplantation

Background

During the immediate postoperative period after liver transplantation (LT), postoperative bleeding and vascular complications (stenosis, thrombosis) are the two most common complications that require therapeutic decisions. Doppler ultrasound (DUS) is the established method for screening vascular patency after LT during the immediate postoperative period. The objective of our study was to evaluate the impact of DUS performed on postoperative days (POD) 1 and 2 on early vascular interventions.

Methods

We studied 200 patients who had undergone living donor or deceased donor liver transplantation between January 2011 and March 2012. Postoperative liver DUS findings of up to POD 14, including patency of hepatic artery, portal vein, and hepatic vein, were retrieved. Patients with normal DUS findings on POD 1 and POD 2 were classified as the normal early DUS group. Patients with abnormal DUS findings at POD1 or POD2 were classified as the abnormal early DUS group. Frequency of vascular interventions was compared between the two groups. Risk factors that predict vascular interventions also were assessed.

Results

On POD 1 and 2, 81.5 % (163/200) had normal DUS findings and management was not altered by subsequent DUS findings. Two patients in the normal group were found to have hepatic artery dissection and hepatic vein thrombosis on routine CT on POD 7 and received vascular intervention. DUS results in the two patients were normal until POD 6, but DUS performed after the CT on POD 7 were consistent with the CT findings. Of the 37 recipients who showed abnormal DUS findings on POD 1 or 2, the DUS findings were normalized or unchanged thereafter in 33 patients and no vascular interventions were performed. Two patients underwent hepatic artery thrombectomy on POD 2, one patient required a portal vein thrombectomy on POD 1, and one patient died on POD 3 due to bleeding. The overall incidence of vascular complication requiring vascular interventions was 2.5 %. Logistic regression identified abnormal DUS findings on POD 1 or 2 as an independent risk factor of vascular complications requiring intervention.

Conclusions

In LT recipients who demonstrate normal DUS findings in the first 2 postoperative days, additional DUS screening may have value only when clinically indicated.     

Three-dimensional multislice helical computed tomography with the volume rendering technique in the detection of vascular complications after liver transplantation

BACKGROUND: Hepatic artery stenosis and thrombosis are common complications in liver transplant patients. Digital subtraction angiography (DSA) has served as the gold standard to make this diagnosis. More recently, three-dimensional helical computed tomographic arteriography (3D CTA) with maximum intensity projection and shaded surface display techniques has been compared with DSA. The purpose of this study was to determine whether 3D CTA with the volume rendering technique is a useful and accurate tool in the detection of vascular complications after liver transplantation. METHODS: Thirty-five consecutive liver transplant patients underwent 3D CTA with volume rendering technique. The standard of reference was DSA for 20 patients and imaging and clinical follow-up for 15 patients. Two blinded reviewers evaluated the axial and 3D CTA images in consensus. RESULTS: 3D CTA with volume rendering technique detected 10 hepatic artery stenoses, six hepatic artery thromboses, two hepatic artery pseudoaneurysms, two splenic artery aneurysms, two portal vein stenoses, and four redundant hepatic arteries. In one case computed tomography (CT) detected a moderate hepatic artery stenosis, while conventional angiography showed a normal artery. The sensitivity of CT for detecting vascular lesions was 100%, specificity was 89% (8 of 9), accuracy was 95% (19 of 20), positive predictive value was 92% (11 of 12), and negative predictive value was 100% (8 of 8). CONCLUSIONS: 3D CTA is a useful and accurate noninvasive technique for detection of vascular complications in liver transplant patients.     

Surgical management of anatomical variations of the right lobe in living donor liver transplantation

OBJECTIVE: To review the anatomical variations of the right lobe encountered in 40 living liver donors, describe the surgical management of these variations, and summarize the results of these procedures. SUMMARY BACKGROUND DATA: Anatomical variability is the rule rather than the exception in liver and biliary surgery. To make effective use of liver segments from living donors for transplantation, surgical techniques must be adapted to the anomalies. METHODS: Donor evaluation included celiac and mesenteric angiography with portal phase, magnetic resonance angiography, and intraoperative ultrasonography and cholangiography. Arterial anastomoses were generally between the donor right hepatic artery and the recipient main hepatic artery. Jump-grafts were constructed for recipients with hepatic artery thrombosis, and double donor arteries were joined to the bifurcation of the recipient hepatic artery. The branches of a trifurcated donor portal vein were isolated during the parenchymal transection, joined in a common cuff, and anastomosed to the recipient main portal vein. Significant accessory hepatic veins were preserved, brought together in a common cuff if multiple, and anastomosed to the recipient cava. The bile ducts were individually drained through a Roux-en-Y limb, and stents were placed in most patients. RESULTS: Forty right lobe liver transplants were performed between adults. No donor was excluded because of prohibitive anatomy. Seven recipients had a prior transplant and five had a transjugular intrahepatic portosystemic shunt (TIPS). Arterial anomalies were noted in six donors and portal anomalies in four. Arterial jump-grafts were required in three. Sixteen had at least one significant accessory hepatic vein, and one had a double right hepatic vein. There were no vascular complications. Multiple bile ducts were found in 27 donors. Biliary complications occurred in 33% of patients without stents and 4% with stents. CONCLUSIONS: Anatomical variations of the right lobe can be accommodated without donor complications or complex reconstruction. Previous transplantation and TIPS do not significantly complicate right lobe transplantation. Microvascular arterial anastomosis is not necessary, and vascular complications should be infrequent. Biliary complications can be minimized with stenting.     

Intrahepatic Segmental Portal Vein Thrombosis After Living-Related Donor Liver Transplantation

Background

Intrahepatic segmental portal vein thrombosis after living-related liver transplantation (LRLT) is uncommon. The cause remains unclear.

Methods

After providing written informed consent, 25 recipients receiving LRLT at our institution from January 2011 to September 2013 were enrolled in this study. We performed triphase computerized tomographic (CT) study of the liver graft of each recipient 1 month after LRLT. The patencies of hepatic artery, portal vein, and hepatic vein were evaluated in detail. The triphase CT scans of the liver of each donor before transplantation also were reviewed. Thrombosis of the intrahepatic segmental portal vein was defined as the occlusion site of the portal vein being intrahepatic. Extrahepatic portal vein thrombosis was excluded in this study.

Results

Among the 25 patients, 2 (8%) developed thrombosis of intrahepatic segmental portal vein. One 47-year-old man received LRLT for hepatitis B viral infection–related liver cirrhosis (Child-Pugh class C) with 3 hepatocellular carcinomas (total tumor volume <8 cm). Another 53-year-old man received LRLT for alcoholic liver cirrhosis (Child-Pugh class C). Both had developed progressive jaundice and cholangitis 1 month after surgery. Intrahepatic biliary stricture was found on the follow-up magnetic resonance images. However, liver triphase CT study demonstrated occlusion of intrahepatic portal vein of segment 8 in each patient. Radiologic interventions and balloon dilatation therapy via percutaneous transhepatic biliary drainage route improved the symptoms and signs of cholangitis and obstructive jaundice for both.

Conclusions

Thrombosis of intrahepatic segmental portal vein is not common but is usually associated with complications of intrahepatic bile duct. Early detection is important, and follow-up CT study of liver is suggested.     

Arterial complications after living-related liver transplantation: single-center experience from West China

Vascular complications after liver transplantation remain a major source of morbidity and mortality for recipients. In particular, patients receiving living-related liver transplantation (LRLT) experience a higher rate of vascular complications owing to the complex vascular reconstruction. Between July 2001 and December 2005, LRLTs were performed in our center on 33 patients with end-stage liver diseases. The 23 men and 10 women had a mean age of 32.6 +/- 11.3 years (range = 5 to 58 years). Of the 33 patients, the percentage of vascular complications was 9.09% (3 cases), including hepatic arterial thrombosis (HAT), hepatic arterial stenosis (HAS), or hepatic artery pseudoaneurysm (HAP) in one patient, respectively. No portal vein or hepatic vein complication occurred in our patients. Thrombectomy was performed in the patient with thrombosis. The patient with stenosis was treated with balloon angioplasty and endoluminal stent placement. The pseudoaneurysm was also successfully embolized to restore the blood flow toward the donor liver. Mean follow-up for all patients after LRLT was 18.0 +/- 5.4 months. The overall postoperative 30-day mortality rate was 6.06% (2/33). The 1-year survival rate was 86.36% in 22 patients with benign diseases and 72.73% in 11 patients with malignant diseases. However, no death was associated with vascular complications. Careful preoperative evaluation and intraoperative microsurgical technique for hepatic artery reconstructions are the keys to prevent vascular complications following LRLT. Immediate surgical intervention is required for acute vascular complications, whereas late complications may be treated by balloon angioplasty and endoluminal stent placement. Embolization may be a safe and effective approach in the treatment of a pseudoaneurysm of the hepatic artery.     

Living-related liver transplantation in children: the 'Parisian' strategy to safely increase organ availability.

PURPOSE: The aim of the authors was to report their experience with living related liver transplantation (LRLT) in children, particularly focusing on the safety of the two-center "Parisian" strategy. METHODS: The records of donors and recipients of 26 pediatric living-related donor liver transplantations performed between November 1994 and March 1998 were reviewed retrospectively. Donors were assessed 1 year after transplantation for medical and overall status. RESULTS: Indications for LRLT included biliary atresia (n = 18), Byler's disease (n = 5), alpha-1-antitrypsin deficiency (n = 1), Alagille syndrome (n = 1), and undefined cirrhosis (n = 1). Liver harvesting consisted of either a complete left hepatectomy (n = 14) or left lateral hepatectomy (n = 12) without vascular clamping. The recipient procedure essentially was the same as in split liver transplantation. Mean overall cold ischemia time averaged 140 minutes (range, 90 to 230 minutes). Twenty-four of 26 patients had end-to-end vascular anastomoses without interposition. Biliary reconstruction consisted of a Roux-en-Y choledochojejunostomy in all patients. All recipients except one received cyclosporine A (CSA). Mean donor hospitalization was 8 days (range, 6 to 13) with normalization of all liver function assays by the time of discharge. There were no donor deaths and two postoperative complications (perihepatic fluid collection and bleeding from the wound). One year after donation, the initial 19 donors had resumed their pretransplant status. Two of the children who underwent transplant died. Thirteen of the recipients required reoperation for hepatic artery thrombosis (n = 2), portal vein thrombosis (n = 2), biliary complications (n = 6), fluid collection (n = 3), small bowel perforation (n = 1), and plication for diaphragmatic eventration (n = 1). With mean follow-up of 2 years, 24 of 26 patients are alive and well (patient and graft survival rate, 92%). CONCLUSIONS: LRLT is still controversial, even with minimal and decreasing donor risk. The "Parisian" strategy consists of harvesting the liver in an adult unit by an adult hepatic surgery team. The transplantation is then performed in a pediatric hospital by the pediatric liver transplantation team. The two steps of the procedure allow units specialized in adult surgery, on one hand, and pediatric liver transplantation, on the other hand, to dedicate themselves completely to their respective procedures, improving the safety of the harvest, and alleviating stress for both the medical staff and the families.     

Venous complications after orthotopic liver transplantation

We report venous complications, including portal vein and hepatic vein stenoses, that required interventional radiological treatment in three pediatric and two adult living related liver transplant recipients. Between April 2001 and April 2005, 81 liver transplantations were performed at our hospital. Sixty-two grafts were from living donors. During follow-up, three portal vein stenoses were identified in three pediatric recipients, and two hepatic vein stenoses in two adult patients. In the children, two had received left lateral segment grafts, and one had received a right lobe graft from two mothers and one father, respectively. The etiologies of liver failure were Alagille syndrome, biliary atresia, and fulminant Wilson's disease. Portal vein stenoses were identified at 8, 11, and 12 months after transplantation; all three patients underwent percutaneous transhepatic portal venous angioplasty with a success rate of 100%. The mean follow-up was 102 days; no recurrence has occurred. In contrast, hepatic venous stenoses were diagnosed in two adult recipients. One of them was a 24-year-old woman with autoimmune hepatitis and the other a 43-year-old man with cryptogenic cirrhosis. Hepatic vein stenoses were diagnosed at 3 and 4 months after transplantation. Both hepatic vein stenoses were dilated with balloon angioplasties via the transjugular route. Venous complications identified by Doppler ultrasonography were confirmed by computerized tomographic angiography. Angioplasty represents an effective and safe alternative to reconstructive surgery in the treatment of venous complications after liver transplantation.     

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.     

儿童肝移植术后门静脉狭窄的诊断与治疗

目的分析儿童肝移植术后门静脉狭窄(PVS)的可能危险因素,并探讨不同治疗方式的临床疗效。 方法回顾性分析2013年6月至2017年12月首都医科大学附属北京友谊医院肝移植中心396例儿童肝移植受者临床资料(年龄≤14周岁)。随访至2018年6月,有26例发生PVS(6.6%)。对于超声怀疑PVS的儿童受者,本中心多选用门静脉血管造影确诊。术后采用超声监测门静脉直径及流速,观察血管通畅情况。采用随访观察并口服药物抗凝治疗、球囊扩张、门静脉支架置入或Meso-Rex分流术治疗PVS。监测肝功能变化,评估有无门静脉相关的移植物损伤,并观察有无门静脉高压相关的症状或体征。 结果26例儿童受者术后发生PVS中位时间为9.5个月(1.3～50.0个月),其中3个月以内发生者占26.9%(7/26),3个月以后占73.1%(19/26)。行介入球囊扩张和支架置入或Meso-Rex分流术共47例次,均未因PVS死亡。2例儿童受者动态随访,期间口服抗凝药物;23例行门静脉球囊扩张术,1例因门静脉冗长行1次门静脉球囊扩张＋支架置入术,10例经1次门静脉球囊扩张术后无效后行二次球囊扩张,7例经二次门静脉球囊扩张术后无效行门静脉支架置入术,2例经门静脉支架置入术后再次狭窄,行Meso-Rex手术。1例口服药物抗凝治疗的儿童受者,随访期间超声提示门静脉流速偏快,其余随访至今未见PVS复发。 结论超声是监测儿童肝移植术后门静脉情况、早期发现PVS的有效办法。发生PVS时,轻症儿童受者可动态随访,期间口服抗凝药物;中重度儿童受者首选门静脉球囊扩张、门静脉支架置入术。Meso-Rex分流术是对门脉支架置入术后PVS复发或发生门静脉闭塞的一种可选择的手术方式。     

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.     

Living-related liver transplantation with renoportal anastomosis for a patient with large spontaneous splenorenal collateral

BACKGROUND: A large splenorenal collateral must be interrupted during liver transplantation to secure adequate portal perfusion. However, this process increases the complexity of the operative procedure and may cause hazardous bleeding. Recently, renoportal anastomosis in portal reconstruction was reported in cadaveric liver transplantation for patients with surgically created splenorenal shunts. We used this technique in a living-related liver transplantation. METHODS: A 29-year-old female with a large spontaneous splenorenal collateral and a portal venous thrombus underwent a living-related liver transplantation. At surgery, the left renal vein was divided and the distal stump was anastomosed to the portal vein of the graft without interrupting collaterals. RESULTS: Adequate portal venous blood flow was maintained throughout the postoperative course. The patient was discharged 9 weeks after transplantation and remains well. CONCLUSION: The renoportal anastomosis could be used for portal reconstruction in living-related liver transplantation for patients with a large splenorenal collateral. It provides adequate portal perfusion without interrupting collateral circulation.     

成人间活体肝移植后小肝综合征的预防：附6例报告

目的：探讨预防成人间活体肝移植术后小肝综合征（SFSS)的方法。 方法：回顾性分析6例成人间活体肝移植(LDLT)的临床资料,包括受体术前血细胞计数、脾脏厚度、门静脉直径、移植物重量与受体体重比（GRWR）、移植物体积与受体标准肝体积比（GV/SLV）及肝静脉重建等,探讨合适体积移植物、良好肝静脉回流、及正常门静脉灌注对SFSS的预防作用。 结果：受体术前均无严重门静脉高压,均没有采用降门静脉压力与血流的措施,6例肝移植物GV/SLV均大于40%,除1例GRWR为0.74%外,余均大于0.8%。6例受体肝静脉重建均良好,重建后肝脏无淤血改变。术后无SFSS发生。 结论：LDLT通过选择合适体积移植物,重建良好的肝静脉回流,控制门静脉压力,防止门静脉过度灌注等有助于预防SFSS的发生。     

彩色多普勒超声对肝移植术后11例血管并发症的诊断

目的评价彩色多普勒超声对肝移植术后血管并发症的诊断意义。方法回顾性分析和总结11例肝移植术后血管并发症的彩色多普勒超声检查资料,检测指标包括肝动脉及左右分支的峰值速度、阻力指数、加速度及加速时间,门静脉平均流速。结果5例经手术或造影证实为动脉并发症(血栓形成2例,肝动脉狭窄2例,肝动脉痉挛1例),彩色多普勒超声表现有肝动脉狭窄处的高速高阻血流并伴有湍流,而狭窄远端肝内动脉峰值速度<40cm/s,阻力指数<0.5,加速时间>0.08s,加速度<300cm/s2,2例肝动脉血栓形成肝门部无动脉血流信号;6例为门静脉并发症(3例门静脉狭窄,3例门静脉血栓形成)。结论彩色多普勒超声对肝移植术后血管并发症的诊断具有重要的指导意义。     

Serious intestinal bleeding from vascular ectasia secondary to portal thrombosis after living-related liver transplantation in a child

Serious intestinal bleeding from vascular ectasia secondary to extrahepatic portal thrombosis is much less frequent than variceal bleeding, and its treatment is not clearly defined. We describe a 4-year-old girl with repeated intestinal bleeding from vascular ectasia, without any varix, with late extrahepatic portal vein thrombosis (PVT) and late hepatic artery thrombosis (HAT) after living-related liver transplantation. The bleeding stopped after simple splenectomy. She has presented neither bleeding nor any serious complications related to splenectomy for 1 year to date. We think uncontrollable hemorrhage from gastrointestinal vascular ectasia secondary to extrahepatic portal thrombosis in a pediatric patient can and should be treated by simple splenectomy, because patients with this complication usually have a normally functioning liver. However, it is not clear whether this procedure is effective for variceal bleeding.     

Relief of hepatic vein stenosis by balloon angioplasty after living-related donor liver transplantation

We have experienced 5 hepatic vein stenoses in 3 children (8 to 23 months old) after living-related liver transplantation (total 48 liver transplants for 48 children between June 1990 and November 1992). The initial symptoms of hepatic vein stenosis were ascites and/or edema. The blood flow of hepatic vessels was monitored by duplex sonography. The mean velocity of the hepatic vein and the portal vein was decreased and flow wave pattern of the stenotic hepatic vein was flat. The patients were treated by percutaneous transhepatic balloon angioplasty. After a successful angioplasty, the mean velocity of the hepatic vein and portal vein increased and pulsatile waves returned to the hepatic vein. Arterial ketone body ratio (acetoacetate/3-hydroxybutylate) increased, promptly followed by recovery of other liver function tests. In 1 patient, this complication occurred three times with intervals of 7 months and 3 months between episodes of hepatic vein stenosis. In conclusion, hepatic vein flow should be monitored routinely with duplex sonography after living-related donor liver transplantation. Percutaneous transhepatic balloon angioplasty is a primary treatment for the stenosis.     

Vascular complications in hepatic transplantation: single-center experience in 14 years

Purpose

To evaluate the spectrum of liver transplantation-related vascular complications that occurred in a single center over the past 14 years.

Materials and methods

Vascular complications and their clinical outcomes were reviewed among 744 liver transplant recipients. All patients underwent Doppler ultrasound with findings correlated with conventional or computed tomography angiography (CTA) in 111 patients.

Results

Among 70 recipients with vascular complications (%0.9), 14/26 patients with hepatic artery thrombosis underwent thrombectomy and arterial reanastomosis; six were retransplanted and six died. Among hepatic artery stenoses, three of nine were treated with balloon angioplasty and six underwent reanastomosis. Among 20 portal vein thromboses, 16 underwent thrombectomy, two patients retransplantation and two died. Seven patients with portal vein stenosis were followed. Two of six hepatic vein stenosis were restored with balloon angioplasty and three patients with metallic stent placement; the one other died. One patient with hepatic vein thrombosis died while the other patient was retransplanted.

Conclusion

Transplantation related hepatic vascular complications diagnosed and managed in timely fashion showed a low mortality rate in our series.     

Preoperative vascular imaging in pediatric liver transplantation

Background/Purpose

There is a considerable variation in the use of vascular imaging techniques in the preoperative assessment of children scheduled for liver transplantation. Duplex Doppler ultrasound scan (US), magnetic resonance angiography (MRA), and conventional angiography are used to varying extents. The authors compared the results of preoperative vascular imaging studies with operative findings to determine their accuracy and usefulness.

Methods

Results of preoperative vascular imaging in 37 consecutive children undergoing cadaveric liver transplantation were compared with operative findings. Those undergoing relatively elective transplantations were investigated by US and MRA (group 1), whereas those requiring urgent transplants were assessed only by US (group 2).

Results

The median age of the cohort (15 boys; 22 girls) was 4 years (19 days to 16 years) and the median weight was 17 kg (2.9 to 82 kg). In group 1 (n = 26), 20 children had a normal-caliber, patent portal vein at transplant and 6 had a narrow but patent portal vein requiring venous reconstruction in 4. The sensitivity and specificity of MRA in the detection of an abnormally narrow portal vein were 100% (6/6) and 95% (19/20), respectively. If reversed or absent flow in the portal vein on US was taken as an indication of a potentially abnormal vein, the sensitivity and specificity of Doppler US were 83% (5/6) and 95% (19/20), respectively. Magnetic resonance angiography revealed arterial anomalies in 4 children but failed to detect small accessory hepatic arteries in 5. The single patient with an aberrant vena cava was identified by MRA. In group 2 (n = 11), venous findings at operation and on US were concordant in 10 (91%) cases; one infant with reversed flow in the portal vein on US had a thrombosed vein at surgery. Magnetic resonance angiography was useful in 2 patient groups: those with reversed flow on Doppler US or suspected portal vein thrombosis in whom an abnormal portal vein was present in 86% (6/7) and infants with the biliary atresia splenic malformation syndrome who had multiple venous and arterial anomalies.

Conclusions

A detailed Doppler examination of the hepatic vasculature by an experienced sonographer/radiologist provides sufficient vascular imaging for most children scheduled for cadaveric liver transplantation. Routine MRA is recommended in children with the biliary atresia splenic malformation syndrome and in those with abnormal duplex Doppler US findings. Although there are limited data in this study, MRA is also valuable in children with Budd-Chiari syndrome, liver tumors, or a previous portosystemic shunt.     

活体肝移植的几点关键外科技术

目的：探讨活体肝移植的几点关键外科技术。方法：2001年1月至2002年3月底,实施活体肝移植11例,其中左半肝8例,左外叶1例,成人右半肝2例;根据术前CT、血管造影和术中B超确定肝切除线,超声电刀离断肝实质,经门静脉灌注原位获取。受体手术采用保留腔静脉的全肝切除。移植肝原位植入,肝静脉重建采用扩大成型吻合技术,显微技术吻合肝动脉,胆道重建采用端端吻合,置“T“管引流。结果：11例供体术后顺利康复出院,未发生严重并发症。11例受体中,1例发生肝动脉血栓形成需再次肝移植,1例因不可逆转的严重排斥反应,于术后72d死亡。10例受体康复出院,肝功能、铜氧化酶恢复正常。结论：活体肝移植对供体是相对安全的。管道重建技术是活体肝移植的重要环节。术前、术中了解供体的解剖变异并正确处理,可降低并发症发生率。     

Magnetic resonance of the hepatic veins with angular reconstruction: application in living-related liver transplantation.

BACKGROUND: Preoperative mapping of the hepatic venous system of the partial liver graft is indispensable to the success of living-related liver transplantation. We assessed the accuracy of magnetic resonance (MR) venography with angular reconstruction in depicting the tributaries of the middle hepatic vein and left hepatic vein in the donors, which was essential in graft retrieval and venoplasty. METHODS: Nineteen living-related liver transplantation donors underwent a pretransplantation survey, including sonography and MRI for hepatic venous evaluation. T1-weighted images were reconstructed manually, using the inferior vena cava as a fixed point for tilting to produce an oblique plane image where both the middle hepatic vein and left hepatic vein could be demonstrated draining into the inferior vena cava. The reconstructed images of the hepatic veins were compared with preoperative sonography, intraoperative sonography, and operative findings. RESULTS: Preoperative sonography and MR findings correlated well with the operative findings in the major hepatic veins. The MR venography of the ramification of the hepatic veins has an accuracy of 93%, the sonography, 84%. Sonography is slightly inferior in the evaluation of the hepatic vein in segment 4 and the left superior hepatic vein, with an accuracy of 73% and 67%, respectively. CONCLUSION: MR venography with angular reconstruction is accurate in depicting the complex distribution of the hepatic veins of the left liver, providing important information for decision making as to the cutting plane during graft retrieval and the method of venoplasty and anastomosis. Thus, unnecessary blood loss could be avoided and vascular complications could be prevented, as these conditions would be unacceptable for a healthy living donor. We propose that MR venography, a rapid and reliable technique, is an appropriate alternative examination or complementary modality to sonography in the pretransplantation evaluation of the living donor.     

Reliability of hepatic artery configuration in 3D CT angiography compared with conventional angiography – special reference to living-related liver transplant donors

Although an accurate anatomical understanding of the hepatic arteries is the most and essential step in living-related liver transplantation (LRLT), the need to reduce the burden place on the donor should be considered in imaging diagnosis. The present study examined the reliability of intravenously enhanced three-dimensional (3D) angiography from multidetector-row computed tomography (MDCT) in evaluating the anatomical configuration of the hepatic arteries comparing with those from conventional angiography by Seldinger method. A total of 109 patients underwent MDCT and 3D images were reconstructed on arterial phase using the volume rendering (VR) method. In the case of 3D angiography, at an infusion rate of 4 ml/s, the extrahepatic hepatic arteries were visualized successfully in all cases (the right, left and middle hepatic artery). The aberrant hepatic arteries were successfully visualized in 23 of 24 cases. The 3D angiography is a reliable method of visualizing the extrahepatic and aberrant hepatic arteries. This minimally invasive examination procedure is useful in individual operative planning and is help to increase the safety of surgery.