Magnetic resonance cholangiography in assessing biliary anatomy in living donors:A meta-analysis

AIM:To establish the role of magnetic resonance cholangiography(MRC)in diagnosis of biliary anatomy in living-donor liver transplantation(LDLT)donors.METHODS:A systematic review was performed by searching electronic bibliographic databases prior to March 2013.Studies with diagnostic results and fulfilled inclusion criteria were included.The methodological quality of the studies was assessed.Sensitivity,specificity and other measures of the accuracy of MRC for diagnosis of biliary anatomy in LDLT donors were summarized using a random-effects model or a fixed-effects model.Summary receiver operating characteristic(SROC)curves were used to summarize overall test performance.Publication bias was assessed using Deek’s funnel plot asymmetry test.Sensitivity analysis was adopted to explore the potential sources of heterogeneity.RESULTS:Twelve studies involving 869 subjects were eligible to the analysis.The scores of Quality Assessment of Diagnostic Accuracy Studies for the included studies ranged from 11 to 14.The summary estimates of sensitivity,specificity,positive likelihood ratio,negative likelihood ratio,diagnostic OR of MRC in diagnosis of biliary anatomy in LDLT donor were 0.88(95%CI:0.84-0.92),0.95(95%CI:0.93-0.97),15.33(95%CI:10.70-21.95),0.15(95%CI:0.11-0.20)and 130.77(95%CI:75.91-225.27),respectively.No significant heterogeneity was detected in all the above four measures.Area under SROC curve was 0.971.Little publication bias was noted across the studies(P=0.557).Sensitivity analysis excluding a study with possible heterogeneity got a similar overall result,which suggested the little influence of this study on the overall results.CONCLUSION:Our results suggest that MRC is a high specificity but moderate sensitivity technique in diagnosis of biliary anatomy in LDLT donors.

Adult-to-adult right lobe living donor liver transplantation:Comparison of endoscopic retrograde cholangiography with standard T2-weighted magnetic resonance cholangiography for evaluation of donor biliary anatomy

AIM: To compare the value of endoscopic retrograde cholangiography (ERC) and standard T2-weighted magnetic resonance cholangiography (MRC) in the evaluation process as adult-to-adult right lobe living donor liver transplantation (LDLTx) demands a successful outcome, and exact knowledge of the biliary tree is implicated to avoid biliary complications, postoperatively.METHODS: After starting the LDLTx program, 18 liver transplant candidates were selected for LDLTx by a stepwise evaluation process. ERC and standard T2-weighted MRC were performed to evaluate the biliary system of the donor liver. The anatomical findings of ERC and MRC mapping were compared using the Ohkubo classification. RESULTS: ERC allowed mapping of the whole biliary system in 15/15 (100%) cases, including 14/15 (93.3%) with biliary variants while routine MRC was only accurate in 2/13 (15.4%) cases. MRC was limited in depicting the biliary system proximal of the hepatic bifurcation. Postoperative biliary complications occurred in 2 donors and 8 recipients. Biliary complications were associated with Ohkubo type C, E or G in 6/8 recipients, and 2/3 recipients with biliary leak received a graft with multiple (≥2) bile ducts. CONCLUSION: Pretransplant ERC is safe and superior over standard MRC for detection of biliary variations that occur with a high frequency. However, precise knowledge of biliary variants did not reduce the incidence of postoperative biliary complications.

Expectations from imaging for pre-transplant evaluation of living donor liver transplantation

Living donor liver transplant(LDLT)is a major surgi-cal undertaking.Detailed pre-operative assessment of the vascular and biliary anatomy is crucial for safe and successful harvesting of the graft and transplantation.Computed tomography(CT)and magnetic resonance imaging(MRI)are currently the imaging modalities of choice in pre-operative evaluation.These cross-sec-tional imaging techniques can reveal the vascular and biliary anatomy,assess the hepatic parenchyma and perform volumetric analysis.Knowledge of the broad indications and contraindications to qualify as a recipi-ent for LDLT is essential for the radiologist reporting scans in a pre-transplant patient.Similarly,awareness of the various anatomical variations and pathological states in the donor is essential for the radiologist to generate a meaningful report of his/her observations.CT and MRI have largely replaced invasive techniques such as catheter angiography,percutaneous cholan-giography and endoscopic retrograde cholangiopan-creatography.In order to generate a meaningful report based on these pre-operative imaging scans,it is also mandatory for the radiologist to be aware of the sur-geon’s perspective.We intend to provide a brief over-view of the common surgical concepts of LDLT and give a detailed description of the minimum that a radiologist is expected to seek and report in CT and MR scans per-formed for LDLT related evaluation.

钆贝葡胺增强MRC与3D-SPACE-T2WI-MRC显示活体肝移植供体胆管的比较

目的比较钆贝葡胺(Gd-BOPTA)CE-MRC与3D-SPACE-T2WI-MRC对活体肝移植供体胆管解剖及变异的显示。方法 32名肝移植供体,术前接受Gd-BOPTACE-MRC与3D-SPACE-T2WI-MRC。以术中胆管造影为标准,分析并比较两种方法诊断胆管变异情况。结果两种方法对胆总管、肝总管、左肝管及右肝管的显示差异有统计学意义(P<0.05),CE-MRC优于3D-SPACE-T2WI-MRC;对胆囊管,左前、后肝管,右前、后肝管及3级以上胆管的显示差异无统计学意义(P>0.05)。术中胆管造影诊断胆管变异17例,3D-SPACE-T2WI-MRC诊断14例,CE-MRC诊断15例,两者联合诊断17例。结论 3D-SPACE-T2WI-MRC与CE-MRC均可用于评估术前肝移植供体胆管解剖,CE-MRC对部分胆管的显示优于3D-SPACE-T2WI-MRC,二者联合应用效果更佳。

MRI一站式综合扫描对活体肝移植的应用价值

目的研究MRI一站式综合扫描对活体肝移植的应用价值。方法选择活体肝移植的患者及供体各20名。进行MRI扫描,包括3.0T磁共振采用常规血管四期增强扫描。磁共振平扫采用flash序列及TSE序列扫描。血管增强后选择与平扫相同的T_1 vibe压脂序列进行扫描。依据个体需要,在注射后40～120 min之间进行延迟扫描。以手术所见为参考标准,比较MRI平扫与一站式MRI综合扫描(MRI平扫+MRCP+血管增强+肝实质增强+延迟)对病灶检出的敏感度,评估其诊断价值。结果 MRI平扫对供体/受体血管变异、胆道变异和癌变的检出敏感性分别为40.0%、72.22%、75.0%。而一站式MRI扫描对病灶检出的敏感性都为100.0%,两种方法对后两种病变的敏感性比较差异有统计学意义(P<0.05)。结论在活体肝移植中一站式MRI综合扫描检查具有重要价值。