Pre-operative hepatic vascular mapping of living donor for liver transplantation using 64-MDCT

Objective

The purpose of the present study was to assess the performance of 64-row MDCT angiography in the mapping of hepatic vascular anatomy in potential living liver donors with special attention paid to the anatomical variants, which influence the donor selection and surgical planning.

Material and Methods

Evaluation of 43 potential living donors was performed using 64-row MDCT scanner to obtain hepatic arterial and venous phases. Eleven subjects were excluded as they did not perform the transplantation surgery. The hepatic arterial (HA) anatomy was evaluated and classified according to Michel classification with special attention given to those considered relative or absolute contraindications for donation and those may alternating the surgical procedure. The origin and course of the artery to segment IV were determined. Portal venous (PV) anatomy was assessed and classified according to Cheng classification. Hepatic venous anatomy was evaluated with special attention paid to middle hepatic vein (MHV) anatomy, significant accessory branches crossing dissection line or that may require additional anastomosis.

Results

64-Row MDCT was done for 43 potential living donors. Eleven subjects were excluded as they did not perform the transplantation surgery. Thirty-two living donors for liver transplantation were enrolled in this study. Standard hepatic arterial anatomy was determined in 19 subjects (59.4%) while 13 candidates (40.6%) showed hepatic arterial variations. The replaced RHA arises from the SMA was the commonest (n = 5, 15.6%). The dominant artery to segment IV was a branch from the left hepatic artery (LHA) in 24 cases (75%) and from right hepatic artery in 8 cases (25%). Classic portal venous anatomy was found in 26 candidates (81.2%) while its variants were detected in 6 cases. Standard hepatic venous anatomy was found in 21 candidates (65.6%). A total of 11 subjects (34.4%) showed hepatic venous variants. 8 cases (25%) had single significant accessory hepatic vein while 3 subjects (9.4%) had two or more significant accessory hepatic veins. MHV confluence was late in 4 candidates (12.5%). An accessory inferior right hepatic vein was the commonest accessory hepatic vein that was detected in 7 cases (21.9%).Compared to surgical findings, MDCT correctly identified hepatic arterial and portal venous anatomy in all cases with no false positive or false negative cases. Sensitivity, specificity, PPV, NPV and accuracy of MDCT in identification of hepatic arterial and portal anatomy were all 100% while for hepatic venous anatomy, the corresponding values were 83.3%, 100%, 100%, 90.1% and 93.8%, respectively.

Conclusion

64-Row MDCT is an essential part of pre-operative evaluation of potential liver donors. It is a non-invasive comprehensive evaluation tool that can show the hepatic vascular anatomic details with precise relationship to liver parenchyma.     

Doppler sonographic abnormalities suggestive of venous congestion in the right lobe graft of living donor liver transplant recipients

OBJECTIVE: Establishing optimal hepatic venous outflow is the key for a successful outcome of living donor liver transplantation using a right lobe graft. The purpose of this article is to illustrate the surgical techniques of middle hepatic vein reconstruction with an interposition vein graft in living donor liver transplant recipients using a modified right lobe graft, normal postoperative Doppler sonographic findings, and various Doppler sonographic abnormalities suggestive of hepatic venous congestion. CONCLUSION: Hepatic venous congestion after living donor liver transplantation using a right lobe graft may produce various abnormalities on Doppler sonography. In addition to allowing the patency of the middle hepatic vein tributaries and interposition vein graft to be assessed during the early postoperative period, Doppler sonography can depict the flow direction in the portal vein and in the middle hepatic vein tributaries; therefore, Doppler sonography can reveal reversal of portal flow direction in patients with acute and severe venous congestion and can show the presence of a functional intrahepatic anastomosis between the hepatic vein tributaries during the follow-up period in those with improved congestion.     

Ascites due to anastomotic stenosis after liver transplantation using the piggyback technique: Treatment with endovascular prosthesis

Liver transplantation preserving the retrohepatic inferior vena cava, the so-called piggyback technique, is becoming more frequently used because it avoids caval cross-clamping during the anhepatic phase of surgery. However, hepatic venous outflow blockade causing ascites seems to be less infrequent after piggyback than with cavo-caval anastomosis. We report a 62-year-old patient who underwent liver transplantation using the piggyback technique and developed a stenosis in the anastomosis between the hepatic veins and the inferior vena cava leading to severe postoperative ascites. Ascites was unresponsive to diuretic therapy and was associated with renal function impairment. Since the etiology of the stenosis was mechanical (torsion), percutaneous transluminal angioplasty was unsuccessful. Finally, an autoexpandable prosthesis was placed across the anastomosis resulting in rapid and permanent (3 years of follow-up) resolution of ascites.     

Multidetector CT in pre- and post-operative evaluation of living-related liver transplantation

Objective

To assess the role of multi-detector CT (MDCT) in the pre and post operative evaluation of both potential donors and recipients for living related liver transplantation (LRLT).

Material and Methods

This prospective study included 26 patients for LRLT and their corresponding donors. For preoperative assessment, all subjects were evaluated by triphasic CT abdomen. CT angiography (CTA) with 3D reconstruction and CT volumetry was additionally done for donors. CT findings were compared to surgical results as gold standard reference. In post-operative evaluation, CT abdomen was performed at least once after transplantation for all recipients and for indicated donors. CTA was done for indicated recipients when US findings were inconclusive.

Results

No statistically significant difference was found between CT volumetry and intraoperative findings. Compared to surgical findings, MDCT identified hepatic arterial and portal venous anatomy with 100% sensitivity and specificity, while for hepatic venous anatomy; it showed sensitivity and specificity of 85.7% and 84.2%. Biliary complications and fluid collections were the commonest in recipients and donors respectively.

Conclusion

MDCT is a single comprehensive non-invasive and accurate imaging modality for preoperative evaluation of liver parenchyma, hepatic vascular anatomy and graft volume and postoperative complications in donors and recipients of LRLT.     

Management of venous outflow complications after liver transplantation

Liver transplantation can be complicated by stenosis of the hepatic venous or inferior vena cava outflow. Venous outflow stenosis occurs at rates of 1 to 6% depending on the type of anastomosis. Stenoses can develop acutely as a result of technical problems or can present much later after the transplant due to intimal hyperplasia or perianastomotic fibrosis. Common clinical presentations include hepatic dysfunction, liver engorgement, ascites, abdominal pain, and occasionally variceal bleeding. Treatment can generally be accomplished via a transjugular approach, but percutaneous transhepatic access may be needed when the anastomosis cannot be catheterized from the jugular access. Angioplasty can achieve technical success in restoring anastomotic patency in close to 100% of cases, but restenosis is frequent. Repeat angioplasties may be needed. In adults and pediatric patients with adult sized hepatic veins, stenting may be a better option. Resolution of clinical signs and symptoms is seen in 73 to 100% of cases. Major complications are uncommon, with stent migration being one of the more difficult complications to manage.     

Combined technetium radioisotope penile plethysmography and xenon washout: a technique for evaluating corpora cavernosal inflow and outflow during early tumescence

Combined technetium radioisotope penile plethysmography and xenon washout is a new technique that measures both corporal arterial inflow and venous sinusoidal outflow during early tumescence in patients with erectile dysfunction. Fourteen patients were studied using 99mTc-RBCs to measure inflow and 133Xe or 127Xe in saline to measure outflow. Tumescence was induced by injecting papaverine intracorporally. Peak corporal rates corrected for outflow (r = 0.88) and uncorrected for outflow (r = 0.91) and change in volume over 2 min centered around peak flow [corrected] (r = 0.96) all correlated with angiography. Outflow measurements did not correlate with intracorporal resistance. Thus, outflow rates alone could not be used to predict venous sinusoidal competence. Normal inflow rate is greater than 20 ml/min; probable normal 12-20; indeterminate inflow 7-12; and abnormal inflow less than 7 ml/min. Technetium-99m radioisotope penile plethysmography and xenon washout can be performed together and both provide a method for simultaneously evaluating the relationship between corporal inflow and outflow rates in patients with erectile dysfunction.     

肝移植术后肝静脉流出道梗阻的介入治疗

目的 探讨肝移植术后肝静脉流出道梗阻(HVO)的介入治疗方法及临床效果.方法 回顾性分析5例肝移植术后(劈离式肝移植2例,活体肝移植3例)发生HVO,实施支架植入(4例)和经皮腔内血管成形术(1例)患者的临床资料和介入技术要点.结果介入治疗3例采取经皮肝穿刺肝静脉人路,2例采取右颈内静脉入路.肝静脉造影显示HVO发生在肝左或肝右静脉与下腔静脉吻合口3例,在肝总静脉与肝右静脉吻合口2例.5例介入治疗均成功,介入术后肝静脉与右心房间压力梯度从(15.4±5.6)mmHg下降到(1.9±1.2)mmHg.术后随访9～482 d,无一例发生再狭窄.术后1例因多器官功能衰竭死亡,4例术前明显升高的血清转氨酶和(或)胆红素术后均恢复正常.术前伴有大茸腹水、消化道出血的2例术后腹水均缓解,消化道出血停止.结论 HVO是肝移植术后少见并发症,危害严重,介入治疗是其安全,有效的治疗方法.     

Role of MDCT angiography in assessment of vascular variant in potential living liver donor transplantation

Purpose

This study intends to asses the impact of multiphase three-dimensional Multidetector Computed tomography (MDCT) angiography in facilitating patient selection and surgical planning in potential donors being evaluated for living adult right lobe liver transplantation.

Patient and methods

Fifty consecutive potential living liver donors who underwent three-dimensional (MDCT) angiography were included. MDCT angiography findings were compared with surgical results.

Results

The overall impact of three-dimensional MDCT angiography in diagnosis of A.

Conclusion

MDCT angiography with multiplanar and three-dimensional techniques is a valuable tool for the evaluation of potential living liver donors that provides complete and comprehensive information on the hepatic vascular anatomy. It allows an optimal graft to be obtained that maintains the balance between blood supply and venous drainage.     

Ultrasonographically normal fetal heart

The fetal heart must be systematically checked in routine ultrasonographic examination to detect any cardiac abnormality. The quality of the examination requires good knowledge of development and anatomy of the fetal heart. A complete examination will study inflow and outflow tracts: inflow tract on the four-chamber view, outflow tract by a static and dynamic study of the great arteries (on section in fetal axial and saggital planes). All cardiac abnormalities indicate the need for a fetal karyotype after a complete morphologic study. Atrioventricular septal defect (ASD) for Down's syndrome and malaligment septal defect of cono-truncal pathology are both excellent signs of chromosome abnormality. Special attention must be paid to cardiac abnormalities without a prenatal diagnosis due to the prognosis risk: complete transposition and total abomalous venous connection. These cardiac abnormalities, as well as complex isolated congenital heart disease, require a cardiopediatric evaluation to determine prognosis and management strategy.     

Transesophageal echocardiography in orthotopic liver transplantation: a comprehensive intraoperative monitoring tool

Intraoperative transesophageal echocardiography is a minimally invasive monitoring tool that can provide real-time visual information on ventricular function and hemodynamic volume status in patients undergoing liver transplantation. The American Association for the Study of Liver Diseases states that transesophageal echocardiography should be used in all liver transplant candidates in order to assess chamber sizes, hypertrophy, systolic and diastolic function, valvular function, and left ventricle outflow tract obstruction. However, intraoperative transesophageal echocardiography can be used to “visualize” other organs too; thanks to its proximity and access to multiple acoustic windows: liver, lung, spleen, and kidney. Although only limited scientific evidence exists promoting this comprehensive use, we describe the feasibility of TEE in the setting of liver transplantation: it is a highly valuable tool, not only as a cardiovascular monitoring, but also as a tool to evaluate lungs and pleural spaces, to assess hepatic vein blood flow and inferior vena cava anastomosis and patency, i.e., in cases of modified surgical techniques. The aim of this case series is to add our own experience of TEE as a comprehensive intraoperative monitoring tool in the field of orthotopic liver transplantation (and major liver resection) to the literature.     

Percutaneous Transhepatic Venous Angioplasty and Stenting in a 9-Month-Old Patient with Hepatic Vein Obstruction After Partial Liver Transplantation

Hepatic venous outflow obstruction is a rare but serious complication after liver transplantation. We report ultrasound-guided percutaneous transhepatic stent placement in a 9-month-old infant with a left lateral split liver transplantation with near-complete hepatic vein obstruction.     

Treatment of hepatic venous outflow obstruction after piggyback liver transplantation

PURPOSE: To evaluate retrospectively the endovascular management of hepatic venous outflow obstruction after piggyback orthotopic liver transplantation. MATERIALS AND METHODS: The study was performed with the approval and under the guidelines of the institutional review board and complied with the Health Insurance Portability and Accountability Act. Informed consent from patients was not required by the institutional review board for this retrospective study. From 1995 to 2003, 13 patients (eight male, five female), including 12 adults and one adolescent (age range, 14-67 years; median age, 52 years), underwent endovascular treatment of hepatic venous outflow obstruction after piggyback orthotopic liver transplantation. Patients gave informed consent for all procedures. Eleven patients received whole livers, and two received living-related donor right liver lobes. Four underwent repeat piggyback orthotopic liver transplantation prior to intervention. Primary stent placement was performed in 12 patients. One patient refused primary stent placement and chose venoplasty alone, but required a stent 5 months later. Short balloon-expandable stents (mean diameter, 14.6 mm +/- 1.1 [standard deviation]) were used to minimize jailing of branch vessels and to resist recoil. Pre- and post-procedural pressure gradients were measured. Follow-up included venography, cross-sectional imaging, and laboratory tests. The Wilcoxon signed rank test or the sign test was performed to compare pre- and post-procedural pressure gradients, body weights, and laboratory values. RESULTS: Technical success (pressure gradient < or = 3 mm Hg) was achieved in 13 of 13 patients, and clinical success, in 12 of 13. Mean pre- and post-procedural pressure gradients were 13.0 mm Hg +/- 1.4 and 0.8 mm Hg +/- 0.3. Mean interval from transplantation to intervention was 348 days +/- 159. Mean follow-up was 678 days (range, 16-2880 days). Technical success did not result in clinical improvement in one patient. Biopsy demonstrated severe hepatic necrosis, likely from prolonged venous congestion, and the patient required repeat transplantation. Only one patient required reintervention for stent migration, and no other complications occurred. No significant restenosis was encountered after stent placement. CONCLUSION: Hepatic venous outflow obstruction is an uncommon but potentially fatal complication of piggyback orthotopic liver transplantation. Endovascular treatment with balloon-expandable stents is effective, safe, and apparently durable.     

Assessment of normal and abnormal erectile function: color Doppler flow sonography versus conventional techniques

The penile arteries were studied with color Doppler flow sonography in 10 subjects with normal and 39 patients with abnormal erectile function. The relationships of systolic and diastolic velocities to spectral waveform changes in the penile arteries in response to tumescence were studied before and after intracorporal injection of vasoactive medications that induce erection. In normal subjects, a characteristic spectral waveform pattern corresponded to increasing intracorporal pressure. Patients with abnormal arterial inflow and/or abnormal venous sinusoidal leakage demonstrated deviation from the patterns noted in normal subjects. Patients with abnormal arterial inflow had lower mean peak systolic velocities than normal subjects. Patients with severe venous sinusoidal incompetence had an arrest of waveform progression with evolution to but not beyond phases 1 or 2 (diastolic flow remained positive). Patients with abnormal arterial inflow and abnormal venous sinusoidal outflow had waveform changes that reflected both processes. Systolic/diastolic velocity and waveform relationships can be used to define the integrity of both the cavernosal artery inflow and venous sinusoidal outflow occlusion mechanisms.     

Detection of biliary and vascular anatomy in living liver donors: Value of gadobenate dimeglumine enhanced MR and MDCT angiography

Objective

To evaluate the performance of magnetic resonance (MR) and multidetector computed tomography (MDCT) in the assessment of living donor's vascular and biliary anatomy, having surgical findings as reference standard.

Methods

Thirty-two living liver donors underwent MR cholangiography (1.5-T; standard cholangiography pulse sequences and delayed acquisitions after administration of biliary contrast agent) for biliary anatomy evaluation. MDCT (16-row multidetector scanner, multiphase protocol, 3 mm slice thickness) was also performed in all cases for the assessment of vascular anatomy before transplantation. Hepatic veins (<4 mm in diameter) were not considered. MR and MDCT images interpretation was performed by two reviewers by consensus, based on source axial images, multiplanar reformats, and three-dimensional (3D) postprocessing images. Surgical intraoperative findings were used as standard of reference.

Results

At surgery, 17 biliary anomalies, 3 portal anomalies, 32 venous and 8 arterial variants were found in the 32 patients. MR correctly identified 15/17 biliary anomalies, with a sensitivity of 88% and a specificity of 93%. MDCT correctly identified 8/8 arterial, 3/3 portal and 29/32 venous variants, with a sensitivity of 100% and 91%, respectively, and a specificity of 100%.

Conclusions

MR and MDCT proved to be efficient in evaluating living liver donor's biliary and vascular anatomy.     

Percutaneous transluminal venoplasty after venous pressure measurement in patients with hepatic venous outflow obstruction after living donor liver transplantation

Purpose  

The aim of this study was to evaluate retrospectively the outcome of percutaneous transluminal venoplasty (PTV) after venous pressure measurement in patients with hepatic venous outflow obstruction following living donor liver transplantation (LDLT).     

Endovascular treatment of hepatic venous outflow obstruction after living-donor liver transplantation

PURPOSE: To evaluate the effectiveness and safety of percutaneous interventional management of hepatic venous outflow obstruction after living-donor liver transplantation (LDLT). MATERIALS AND METHODS: Percutaneous balloon angioplasty (n = 5) and stent placement (n = 22) were attempted in 27 patients with hepatic venous outflow obstruction. Patient follow-up included clinical and laboratory data collection, Doppler ultrasonography (US), hepatic venography, and computed tomography. The following parameters were documented retrospectively: technical success and complications, clinical improvement, and recurrence. Technical success was defined as elimination or successful reduction of pressure gradients across the stenosis and clinical success was defined as amelioration of presenting signs. Recurrence was defined as relapse of clinical signs with hepatic venous anastomotic restenosis on Doppler US. RESULTS: Technical success was achieved in all patients. The mean pressure gradients across the stenoses before and after the procedure were 10.6 mm Hg +/- 6.4 (range, 3-39 mm Hg) and 2.4 mm Hg +/- 2.6 (range, 0-8 mm Hg), respectively (P < .001). Three of the five patients who underwent balloon angioplasty developed recurrent stenosis 1-5 weeks after the procedure. These patients underwent repeat balloon angioplasty, and two of them eventually underwent stent placement (n = 1) or surgical repositioning (n = 1) of the graft. Three of the 22 patients who underwent stent placement required a second stent placement procedure because of malpositioning, partial migration, and acute angulation. During the mean follow-up period of 49 weeks +/- 47 (range, 3-214 wk), clinical success was achieved in 20 of 27 patients (73%). CONCLUSION: Percutaneous interventional management is an effective and safe adjunct for the treatment of hepatic venous outflow obstruction after LDLT.     

肝移植术后并发症的CT和MRI诊断

目的:分析肝移植术后各种并发症的CT、MRI表现,评价CT、MRI在肝移植术后并发症中的诊断价值。方法:回顾性分析24例肝移植术后发生并发症的患者的CT、MRI资料,全部病例并发症均经手术、肝组织活检或血管、胆道造影证实。结果:24例患者CT、MRI诊断门脉主干吻合口狭窄4例;肝动脉狭窄3例;下腔静脉吻合口狭窄1例;胆管吻合口狭窄4例;肝门水平非吻合口狭窄5例;移植排异反应4例,肝癌复发7例。结论:CT、MRI能发现大部分肝移植术后并发症,是诊断肝移植术后并发症的有效方法。     

肝移植术后肝静脉和下腔静脉梗阻的诊断及介入治疗

目的 探讨肝移植术后肝静脉、下腔静脉梗阻的诊断及介入治疗技术.方法 在831例原位肝移植(OLT)、26例活体肝移植(LDLT)患者中,共有11例在移植术后2～111 d经血管造影证实为肝静脉、下腔静脉梗阻并进行了介入治疗.其中肝静脉吻合口狭窄或闭塞5例、下腔静脉吻合口狭窄5例、肝静脉狭窄伴下腔静脉吻合口狭窄1例.11例中,5例为成人OLT、4例为LDLT、2例为儿童减体积OLT,介入治疗前9例接受了肝脏CT、2例接受了MR增强扫描.术后随访患者肝肾功能指标、临床症状及肝静脉、下腔静脉血流状况.对11例患者的影像资料、介入治疗技术要点和治疗效果进行回顾性分析.介入治疗前后梗阻两端静脉压力差比较,采用配对t检验.结果 11例患者,CT或MR检查均可明确显示肝脏淤血范围、肝静脉或下腔静脉梗阻部位及程度;其中4例肝静脉梗阻和5例下腔静脉梗阻者行支架植入治疗,1例肝静脉梗阻者行经皮腔内血管球囊扩张术(PTA),1例肝静脉伴下腔静脉梗阻者,行肝静脉PTA和下腔静脉支架植入,介入治疗手术均成功.术后检测梗阻两端静脉压力差为(2.9±1.7)mm Hg(1 mm Hg=0.133 kPa),较术前(16.5±4.1)mm Hg明显下降(t=11.5,P＜0.01).术后10例患者临床症状改善,肝肾功能恢复;1例肝功能恶化,于术后第9天死于多器官功能衰竭.患者术后随访9～672 d,2例肝静脉PTA治疗者术后1个月内发生血管再狭窄,支架植入治疗者未发生再狭窄,无严重并发症发生.结论 支架植入是治疗肝移植术后肝静脉和下腔静脉梗阻安全、有效的方法;术前CT或MR对明确肝淤血范围及静脉梗阻具有重要价值.     

Multislice computed tomography in the preoperative assessment of adult-to-adult living donor liver transplantation: personal results

PURPOSE: To evaluate the possible role of multislice spiral computed tomography (MSCT) as the sole imaging examination in the preoperative assessment of potential donors undergoing adult-to-adult living donor liver transplantation (LDLT). MATERIALS AND METHODS: Fifteen patients underwent MSCT with 0.5-second gantry rotation time. Pre- (4 X 2.5 mm collimation) and post-contrast (4 X 1 mm collimation) acquisitions during arterial and portal venous phases were performed after intravenous administration of 140 ml of non ionic contrast agent at 4-5 ml/s, with a delay time of 25 and 60 seconds, respectively. Pre-contrast scans with 80 and 140 kVp were acquired at the same level used to assess liver density. Real-time interaction with the post-contrast 3D data set was performed on a dedicated workstation to determine total and lobar liver volume, and to assess arterial and venous vascular anatomy. RESULTS: Steatosis was found in three patients, who as a consequence were excluded as possible candidates. MSCT correctly identified five cases of arterial anatomical variations: two cases of the right hepatic artery arising from the superior mesenteric artery, two cases of the common hepatic artery arising from the superior mesenteric artery and one case of the left hepatic artery arising from left gastric artery. In two cases portal trifurcation was considered a criterion for exclusion. A 4% error in the liver volume calculation was found at surgery, in no case considered significant. Two patients underwent surgery and three have been short-listed. CONCLUSIONS: MSCT enables complete preoperative evaluation of potential donors undergoing LDLT. Total and lobar volume determination provided accurate and reproducible information. MSCT enabled correct surgical planning without intra-operative complications. One of the limits of the technique was the poor visualization of the biliary anatomy with the need to perform an intraoperative cholangiography in all the patients.     

多层面CT在肝移植受体术前评估中的应用

目的:探讨多层面CT在肝移植受体术前评估中的应用价值.材料和方法:我们总结分析了自2003年11月至2004年8月52例接受多层面CT检查的晚期肝病患者.采用薄层动态增强扫描,横断面图像 CT血管造影技术,评估肝脏实质病变及血管变异情况.结果:其中接受肝移植手术26例,其中有6例肝动脉变异,与术前判断完全吻合.5例门脉癌栓形成及5例血栓形成中各有1例误诊.结论:多层面CT是一种快捷、无创、价廉的检查手段,可为肝移植受体术前评估提供详尽且准确的解剖及病变信息.