Living donor liver transplantation in adults

Living donor liver transplantation in Europe

Living donor liver transplantation (LDLT) sparked significant interest in Europe when the first reports of its success from USA and Asia were made public. Many transplant programs initiated LDLT and some of them especially in Germany and Belgium became a point of reference for many patients and important contributors to the advancement of the field. After the initial enthusiasm, most of the European programs stopped performing LDLT and today the overall European activity is concentrated in a few centers and the number of living donor liver transplants is only a single digit fraction of the overall number of liver transplants performed. In this paper we analyse the present European activities and highlight the European contribution to the advancement of the field of LDLT.

Wnt agonist stimulates liver regeneration after small-for-size liver transplantation in rats

AIM

Liver regeneration is inhibited in small-for-size grafts, which plays a role in the failure of partial liver grafts after transplantation. The Wnt/β-catenin signaling pathway plays a critical role in liver development, regeneration and homeostasis. In this study, we investigated whether pharmacological activation of Wnt signaling improves liver regeneration after small-for-size liver transplantation.

METHODS

The livers of male Sprague-Dawley rats were reduced to approximately 50% and 30% of their original sizes and transplanted. A Wnt agonist (2-amino-4-[3,4-[methylenedioxy]benzylamino]-6-[3-methoxyphenyl] pyrimidine], 5 mg/kg bodyweight) or an equal volume of vehicle was administrated i.p. into the donor 1 h before the transplantation. Tissue and blood samples were collected at various times after transplantation, and a survival study was performed.

RESULTS

Hepatic expression of active β-catenin and its downstream target gene Axin2 were decreased in 30% of liver grafts after transplantation while the Wnt agonist increased their expression similar to the 50% liver grafts. The Wnt agonist reversed inhibition of cyclin D1 expression and adenosine triphosphate production in the 30% liver grafts compared with the 50% grafts. The Wnt agonist also attenuated hepatocellular injury and increased the hepatocyte proliferation response, liver regeneration rate and survival after transplantation of the 30% liver graft.

CONCLUSION

Activation of Wnt/β-catenin signaling in liver grafts by pharmacological pretreatment can accelerate regeneration in a partial liver transplant model.

Major complications of adult right lobe living liver donors

BACKGROUND

The right lobe of the liver is generally preferred for living donor liver transplantation in adult patients with end-stage liver disease. It is important to know the preoperative factors relating to the major postoperative complications. We therefore evaluated the possible risk factors for predicting postoperative complications in right lobe liver donors.

METHODS

Data from 378 donors who had undergone right lobe hepatectomy at our center were evaluated retrospectively. The factors we evaluated included donor age, gender, body mass index (BMI), remnant liver volume, operation time, history of previous abdominal surgery, inclusion of the middle hepatic vein and variations in the portal and bile systems.

RESULTS

Of the 378 donors, 219 were male and 159 female. None of the donors died, but 124 (32.8%) donors experienced complications including major complications (Clavien scores III and IV) in 27 (7.1%). Univariate analysis showed that complications were significantly associated with male gender and higher BMI (P<0.05), but not with donor age, remnant liver volume, operation time, graft with middle hepatic vein, variations in the portal and bile systems and previous abdominal surgery (P<0.05). Multivariate logistic regression analysis showed that major complications were significantly associated with male gender (P=0.005) and higher BMI (P=0.029). Moreover, the Chi-square test showed that there were significant relationships between major complications and male gender (P=0.010, X2=6.614, df=1) and BMI >25 kg/m2 (P=0.031, X2=8.562, df=1). Of the 96 male donors with BMI >25 kg/m2, 14 (14.6%) with major complications had significantly smaller mean remnant liver volume than those (82, 85.4%) without major complications (32.50%+/-4.45% vs 34.63%+/-3.11%, P=0.029).

CONCLUSION

Male donors with BMI >25 kg/m2 and a remnant liver volume ≤32.50% had a significantly increased risk for major complications.

Computer-assisted surgical planning in adult-to-adult live donor liver transplantation: how much does it help? A single center experience

BACKGROUND

Preoperative imaging and donor selection are cardinal components of adult-to-adult live donor liver transplantation (ALDLT). The purpose of this study was to evaluate our three-dimensional (3D) computed tomography image-derived computer-assisted surgical planning (3D CASP) in ALDLT.

METHODS

Eighty-three consecutive ALDLTs (71 right and 12 left) were planned with 3D CASP. Graft, remnant, and total liver volume compliance were calculated and compared with actual intraoperative values. Computed risk analysis encompassing territorial liver mapping, functional (safely drained) volumes, and outflow congestion volumes in grafts and remnants allowed for the individualized management of the middle hepatic vein (MHV).

RESULTS

Graft volume compliance was 13.5%±4.4%. Three small-for-size (SFS) grafts with lethal SFS syndrome (SFSS) had nonsignificant volume compliance with maximal graft volume-body weight ratios of less than 0.83. Seven SFS grafts with reversible or absent SFSS showed maximal graft volume-body weight ratios of 0.9 to 1.16. Significant differences were identified for (a) virtual graft and remnant congestion volumes of risky versus nonrisky MHV types (49%±6% and 34%±7% vs. 29%±8% and 33%±12%, P<0.001 and P<0.02, respectively) and (b) virtual mean functional versus surgical volumes of grafts (527±119 vs. 963±176 mL, P<0.0001) and remnants (419±182 vs. 640±213 mL, P<0.001).

CONCLUSIONS

CASP allowed for (a) prevention of SFSS in extremely small grafts by predicting donor liver plasticity and (b) individualized MHV management for both donors and recipients based on functional graft/remnant volume analysis.

Donor complications among 500 living donor liver transplantations at a single center

INTRODUCTION

Living donor liver transplantation (LDLT) has become necessary because of the shortage of cadaveric organs. We retrospectively analyzed 500 living donor hepatectomies using the Clavien classification system for complications to grade their severity.

MATERIALS AND METHODS

We retrospectively identified and applied the Clavien classification to 500 consecutive donors who underwent right for LDLT left hepatectomy between January 2007 and August 2011.

RESULTS

The 149 complications were observed in 93 of 500 (18.6%) donors who were followed for a mean 30 months. There wan no donor mortality. Complications developed in 85 (18.6%) right 5 (35.7%) left, and 3 (10%) left lateral segment hepatectomy donors. The overall incidence of reoperations was 7.2%. Seventy-seven of 149 complications were grade I (51.6%) or 9 grade II (6%). The major complications consisted of 27 (18.1%) grade IIIa, 35 (23.4%) grade IIIb, and 1 (0.6%) grade IVa. Grade IVb and grade V complications did not occur. The most common problems were biliary complications in 14 of 181 donors (7.7%).

CONCLUSION

Donors for LDLT experienced a range of complications.

Transdifferentiation: a cell and molecular reprogramming process

Evidence has emerged recently indicating that differentiation is not entirely a one-way process, and that it is possible to convert one cell type to another, both in vitro and in vivo. This phenomenon is called transdifferentiation, and is generally defined as the stable switch of one cell type to another. Transdifferentiation plays critical roles during development and in regeneration pathways in nature. Although this phenomenon occurs rarely in nature, recent studies have been focused on transdifferentiation and the reprogramming ability of cells to produce specific cells with new phenotypes for use in cell therapy and regenerative medicine. Thus, understanding the principles and the mechanism of this process is important for producing desired cell types. Here some well-documented examples of transdifferentiation, and their significance in development and regeneration are reviewed. In addition, transdifferentiation pathways are considered and their potential molecular mechanisms, especially the role of master switch genes, are considered. Finally, the significance of transdifferentiation in regenerative medicine is discussed.

Computed tomographic cholangiography in living liver transplant donors: factors determining the degree of contrast enhancement

OBJECTIVE

To determine factors affecting liver and bile duct contrast enhancement during computed tomographic cholangiography (CTC) in living-donor transplant candidates.

METHODS

Forty-four candidates underwent preoperative triphasic CT followed by intravenous infusion of 20 mL of iodipamide for CTC. Body size indices and liver volume were correlated to parenchymal and biliary enhancement. Bile duct visibility was compared to duct enhancement.

RESULTS

Poorly visualized first- and second-order bile ducts demonstrated diminished enhancement (P < 0.015). Both CTC parenchymal and biliary enhancement correlated inversely with body surface area, height, and weight (P < 0.001); inverse correlation was also seen between liver volume and parenchymal enhancement (P < 0.001). A moderately positive correlation was noted between CTC biliary and parenchymal portal venous enhancement (r = 0.421; P = 0.004).

CONCLUSIONS

Computed tomographic cholangiography parenchymal and biliary enhancement diminishes with increased body size and liver volume, supporting a need for adjustable contrast dosing. Portal venous parenchymal enhancement may serve as a preinfusion indicator.

Short- and long-term donor morbidity in right lobe living donor liver transplantation: 91 consecutive cases in a European Center

The lack of use of a common grading system in reporting morbidity impedes estimation of the true risk to a right lobe living donor (RLLD). We report outcomes in 91 consecutive RLLD's using the validated 5-tier Clavien grading and a quality of life (QOL) questionnaire. The median follow-up was 79 months. The donors were predominantly female (66%), 22 (24%) received autologous blood transfusions. Fifty-three complications occurred in 43 donors (47% morbidity), 19 (37%) were ≥ Grade III, biliary fistula (14%) was the most common. There was no donor mortality. Two intraoperative complications could not be graded and two disfiguring complications in female donors were graded as minor. Two subgroups (first 46 vs. later 45 donors) were compared to study the presence if any, of a learning curve. The later 45 donors had lesser autologous transfusions, lesser rehospitalization and no reoperation and a reduction in the proportion of ≥ Grade III (major) complications (24% vs. 50%; p = 0.06). In the long term, donors expressed an overall sense of well being, but some sequelae of surgery do restrain their current lifestyle. Our results warn against lackadaisical vigilance once RLLD hepatectomy becomes routine.

Living donor liver transplantation using dual grafts: Ultrasonographic evaluation

AIM: To evaluate the dual-graft living donor liver transplantation (LDLT) with ultrasonography, with special emphasis on the postoperative complications.

METHODS: From January 2002 to August 2007, 110 adult-to-adult LDLTs were performed in West China Hospital of Sichuan University. Among them, dual-graft implantations were performed in six patients. Sonographic findings of the patients were retrospectively reviewed.

RESULTS: All the six recipients survived the dual-graft adult-to-adult LDLT surgery. All had pleural effusion. Four patients had episodes of postoperative abdominal complications, including fluid collection between the grafts in three patients, intrahepatic biliary dilatation in two, hepatofugal portal flow of the left lobe in two, and atrophy of the left lobe in one.

CONCLUSION: Although dual-graft LDLT takes more efforts and is technically complicated, it is safely feasible. Postoperative sonographic monitoring of the recipient is important.

Inhibition of matrix metalloproteinase-9 attenuates acute small-for-size liver graft injury in rats

Ischemia/reperfusion (I/R) and portal hypertension have been implicated in small-for-size liver graft dysfunction. Matrix metalloproteinases-2 and -9 (MMP-2/9) are critically proposed to involve in hepatic I/R injury and activated by hemodynamic force. We hypothesized that MMP-2/9 overexpression played a crucial role in acute graft injury following small-for-size liver transplantation (LT). Rats were randomly assigned into four groups: 75% partial hepatectomy (PH); 100% LT; 25% LT and 25% LT treated with CTT peptide (MMP-2/9 inhibitor). ELISA, real-time PCR, gelatin zymography and immunohistochemistry were used to determine the expression pattern of MMP-2/9 in liver tissue. MMP-9 expression was significantly increased 6 h after reperfusion and reached a peak 12 h in the 25% LT group, whereas MMP-2 was expressed in all groups invariably. Compared with the 25% LT group, rats from CTT-treated group exhibited markedly decreased alanine aminotransferase and total bilirubin values, downregulated proinflammatory cytokines, attenuated malondialdehyde (MDA) and myeloperoxidase (MPO) activities, and improved liver histology. Likewise, MMP-9 inhibition significantly reduced number of TUNEL-positive cells and caspase-3 activity, along with decreased protein levels of Fas and Fas-L. Specifically, rat survival was also improved in the CTT-treated group. These results support critical function of MMP-9 involved in acute small-for-size livergraft injury.

Adult living liver donors have excellent long-term medical outcomes: the University of Toronto liver transplant experience

Right lobe living donor liver transplantation is an effective treatment for selected individuals with end-stage liver disease. Although 1 year donor morbidity and mortality have been reported, little is known about outcomes beyond 1 year. Our objective was to analyze the outcomes of the first 202 consecutive donors performed at our center with a minimum follow-up of 12 months (range 12-96 months). All physical complications were prospectively recorded and categorized according to the modified Clavien classification system. Donors were seen by a dedicated family physician at 2 weeks, 1, 3 and 12 months postoperatively and yearly thereafter. The cohort included 108 males and 94 females (mean age 37.3 +/- 11.5 years). Donor survival was 100%. A total of 39.6% of donors experienced a medical complication during the first year after surgery (21 Grade 1, 27 Grade 2, 32 Grade 3). After 1 year, three donors experienced a medical complication (1 Grade 1, 1 Grade 2, 1 Grade 3). All donors returned to predonation employment or studies although four donors (2%) experienced a psychiatric complication. This prospective study suggests that living liver donation can be performed safely without any serious late medical complications and suggests that long-term follow-up may contribute to favorable donor outcomes.

Living-donor liver transplantation in adults

INTRODUCTION

The technique of paediatric living-donor liver transplantation (LDLT) has become standardized. In adults, however, there is scope for innovation. Unlike cadaveric whole-size liver transplantation and paediatric LDLT, size matching between the liver graft and the recipient by body weight has been a major challenge in adult LDLT because it is important to provide an adequate graft mass to the recipient while leaving a sufficient mass of remnant liver in the donor to ensure donor safety.

GROWING POINTS

In adult LDLT, liver grafts have been selected to meet graft-recipient size-matching requirements. In 1996, the Hong Kong group pioneered the use of the right-lobe grafts vein to overcome the volume insufficiency often encountered with the left-lobe liver grafts. Subsequently, the Asan group introduced modified right-lobe grafting with interposition vein grafts to drain the venous outflow of the anterior sector, thus increasing the functioning hepatocyte mass, and this group initiated dual left-lobe liver grafts to overcome both donor risk and volume insufficiency.

AREAS OF AGREEMENT AND CONTROVERSY

Although the surgical procedures for both donors and recipients are more complex for adult LDLT than for whole-organ deceased donor transplantation, the outcomes in large-volume centers are now similar. Accordingly, the indications for adult LDLT are continually being expanded.

AREAS TIMELY FOR DEVELOPING RESEARCH

In performing these procedures, it is crucial to minimize the risks of morbidity and mortality to the healthy live donor. This review focuses on the current technical development and discusses the ethical issues of adult LDLT.

[How can the number of liver transplantations be increased?]

The number of patients suitable for liver transplantation is progressively increasing due to the excellent results achieved with this procedure, giving rise to a growing imbalance in the number of candidates on the waiting list and the number of donors. This situation has prompted transplant teams to search for alternatives to increase the number of liver grafts. On the one hand, the criteria for donation have been broadened to include donors with advanced age, liver steatosis, hepatitis B and C viruses, neoplasms, and benign underlying diseases. On the other hand, new transplant techniques have been used with grafts from split livers, living donors, sequential or domino transplants and non-heart-beating donors. Other options such as xenotransplantation and hepatocyte transplants currently lack clinical applicability.

[The role of imaging methods in the pre- and intra-operative evaluation, and in post-operative follow-up of living donors in liver transplantation in Hungary]

The evaluation protocol for liver donors can vary from centre to centre, but the main points are the same. Medical history, physical examination, common laboratory tests and psychosocial evaluation are followed by imaging, and specific haemostasis and viral serology tests. The first imaging examinations have the aim of excluding any disease; conventional chest radiography and abdominal ultrasound are performed. Liver volume, fat content, and vascular and biliary anatomy are then evaluated with contrast-enhanced, multiphase, multidetector row CT/CTA and MR cholangiography. Ultrasound guided liver biopsy, and in some cases digital subtraction angiography, should also be performed. During the first phase of the donor operation, intraoperative investigations are done: cholangiography for the final evaluation of the biliary tree and ultrasound of the hepatic and portal venous system to help draw the resection plane. Donors have regular imaging examinations in the early postoperative period for early detection of complications: mainly US or CT to check the remnant hepatic vascularisation and fluid collections in the operated area, or X-ray for thoracic disorders. It is recommended that regular checkups are performed in the late postoperative period. The paper describes the imaging protocol for donor evaluation applied at our institute at the beginning of our living related liver transplantation programme.

Retrospective analysis of the causes of rejection of potential donors for living related liver transplantation

BACKGROUND

A major prerequisite for living related liver transplantation is to ensure both donor safety and optimal graft quality. Therefore, excluding unsuitable donor candidates should be an important priority of the transplant team.

PURPOSE

To analyze the criteria for exclusion of potential living related liver donors.

PATIENTS AND METHODS

From November 2000 to March 2005, 327 potential living related donors for 136 potential recipients for liver transplantation were screened and worked up at the Liver Transplant Center, King Abdul Aziz Medical City. They were evaluated in a stepwise manner, including medical, physical, laboratory, psychosocial, and imaging assessment. Data regarding potential donors were retrospectively reviewed. Reasons for rejection of disqualified donors were analyzed.

RESULTS

Out of the 327 potential donors, 223 (68.2%) were rejected at an early stage. A total of 104 cases (31.8%) had computed tomographic (CT) volumetry and/or magnetic resonance cholangiography (MRCP). While 44 (42.3% of those who had CT volumetry and/or MRCP) had their workup completed and proved to be suitable candidates, 24 (23%) went for surgery. Causes for donor rejection were classified as donor-related factors (inadequate volume, unsafe anatomy, abnormal liver function tests, medical/psychiatric, fatty liver, etc.; n = 191) and recipient-related factors (too ill, died, received cadaveric transplant, etc.; n = 112).

CONCLUSION

In our experience, as well as in those from other centers, a small proportion of potential donors prove to be satisfactory candidates. Therefore, strict adherence to a stepwise evaluation process is of utmost importance, so unsuitable potential donors can be disqualified, as early as possible during workup.

Three-quarters of right liver donors experienced postoperative complications

A donor right hepatectomy (RH) is associated with a higher rate of morbidity than a left hepatectomy. Therefore, the precise morbidity should be known to improve the success of donor RH implementation. However, the rate of complication varies according to the individual definition of morbidity. This study prospectively analyzed the outcomes of 83 consecutive living donor RHs between January 2002 and July 2004 using a standardized classification of the severity of complications. The morbidity was classified using the modified Clavien system: grade I for minor complications; grade II for potentially life-threatening complications requiring pharmacological treatment; grade III for complications requiring invasive intervention; grade IV for complications causing organ dysfunction requiring intensive care unit management; and grade V complications resulting in the death of the patient. The donors were followed-up regularly for at least 12 months. No donor death or relaparotomy was noted. Overall, 65 out of 83 donors (78.3%) experienced postoperative complications: grades I, II, III, IV, and V complications in 64 (77.1%), 11 (13.3%), 1 (1.2%), 0, and 0 patients, respectively. The most common grade I complications were hyperbilirubinemia (n = 31) and pleural effusion (n = 31), and bile leakage in grade II (n = 7). The bilirubin and alanine aminotransferase levels were normal in 92.7% of donors at the 1-year follow-up. In conclusion, although most of these adverse events were minor and self-limited, 78% of right liver donors still experienced morbidity. Therefore, continuous standardized reporting of the donor morbidity as well as meticulous surgery and intensive care are essential for the success of donor RH implementation.

Computer-assisted operative planning in adult living donor liver transplantation: a new way to resolve the dilemma of the middle hepatic vein

An adequate venous outflow is essential for securing viability of both graft and remnant in adult living donor liver transplantation (ALDLT). Seventy-five potential live liver donors were evaluated for LDLT by means of an "all-in-one" CT, which defined the biliary tree, portal vein, hepatic artery, and hepatic vein anatomy. The acquired data sets were further analysed by means of the software HepaVision (MeVis, Germany). Only a minority (29%) of potential donors were found to have a vascular and biliary anatomy consistent with the classically described "normal" patterns. The vast majority (71%) had "anatomical variations". Thirty-nine (52%) donors underwent ALDLT hepatectomy. The right hepatic vein was dominant in 64 cases, representing 48 +/- 6% of the total liver volume (TLV). The middle hepatic vein was dominant in 11 cases, making up 40 +/- 8% of the TLV. The left hepatic vein was never dominant. The volume contribution of the middle hepatic vein (MHV) was 114-782 ml for the right and 87-419 ml for the left hemiliver. Computer-assisted planning allows for the 3D reconstruction of the vascular and biliary anatomy, automatic calculation of the total and territorial liver volumes, and risk analysis of hepatic vein dominance relationships. This comprehensive data acquisition supports preoperative evaluation and provides a high degree of safety for donors and improved outcomes for recipients.

Intraoperative blood loss is a risk factor for complications in donors after living donor hepatectomy

Complications in a donor are a distressing but inevitable occurrence, since graft procurement is a major undertaking. Although the technique for procurement has some similarities to hepatic resection, a donor is very unlike a patient with malignancy. The risk factors identified in these patients cannot be extrapolated to donors. Donor hepatectomy carried out from June 1995 to March 2005 in Chang Gung Memorial Hospital, Kaohsiung Medical Center was reviewed with the aim of identifying risk factors for complications. There were 204 living donor liver transplants, with 205 donor hepatectomies, as 1 living donor liver transplantation was a dual graft. Ten donors (4.88%) suffered complications. There was no difference in terms of age, gender, body weight, operation, and parenchymal time between those who had complications and those who did not. There was also no difference in liver function tests between the 2 groups of donors, but the total bilirubin was significantly higher in donors with complications. The graft weight and remnant liver volume were also similar. The proportion of donors with fatty liver was the same between the 2 groups. The mean blood loss in donors with complications was 170 +/- 79 mL, and that for donors without complications was 95 +/- 77 mL. There was a statistically significant greater blood loss in donors with complications (P < 0.05). The number of segments removed in donors with complications was also higher compared to donors without complications (P < 0.03). Using multivariate analysis, intraoperative blood loss and the number of segments removed were found to be independent risk factors for donor complications. Intraoperative blood loss during graft procurement must be kept low to minimize complications in donors.

Feasibility of left lobe living donor liver transplantation between adults: an 8-year, single-center experience of 107 cases

Operative mortality for a right lobe (RL) donor in adult living donor liver transplantation (LDLT) is estimated to be as high as 0.5-1%. To minimize the risk to the donor, left lobe (LL)-LDLT might be an ideal option in adult LDLT. The aim of the study was to assess the feasibility of LL-LDLT between adults based on a single-center experience of 107 LL-LDLTs performed over 8 years. The mean graft weight of LL grafts was 452 g, which amounted to 40.5% of the estimated standard liver volume of the recipients. The overall 1-, 3- and 5-year patient survival rates in LL-LDLT were 81.4, 76.9 and 74.7%, respectively, which were comparable to those of RL-LDLT. Twenty-six grafts (24.3%) were lost for various reasons with three losses directly attributable to small-for-size graft syndrome. Post-operative liver function and hospital stay in LL donors were significantly better and shorter than that in RL donors, while the incidence of donor morbidity was comparable between LL and RL donors. In conclusion, LL-LDLT was found to be a feasible option in adult-to-adult LDLT. Further utilization of LL grafts should be undertaken to keep the chance of donor morbidity and mortality minimal.

Analysis of postsurgical complications in 75 living liver transplantation donors

Seventy-five living donor liver hepatectomies were performed at our transplantation center between April 1990 and December 2004. We collected the data from patient charts, files, and the Baskent University Liver Registry. There were 39 male and 36 female donors (mean age, 35.1 +/- 9.3 years). We have performed 29 (38.6%) left hepatic lobectomies, 18 (24%) left lateral segmentectomies, 26 (34.6%) right lobectomies, and two (2.6%) donors had simultaneous living donor nephrectomy plus left lobe hepatectomy. The mean remnant liver volume was 598 +/- 168 cm(3) (range, 410-915 cm(3)). The mean percentage of remnant liver for the donor was 55.2%. Mean postoperative hospital stay was 10 +/- 4.4 days. After surgery, there was no mortality or reoperation. We saw 15 (20%) postsurgical complications in 14 donors. Intra-abdominal collection was seen in five (6.6%) patients. Biliary leak was seen in four patients. Portal vein thrombosis was seen in one patient, and a pulmonary embolus developed in one liver donor. Patient safety must be the primary focus in living-donor liver transplantation. These donors face significant risks, including substantial morbidity and death. More experience, improved surgical techniques, and meticulous donor evaluation will help minimize morbidity and mortality for both living liver donors and recipients.

Evaluation of Living Liver Donors with an All-inclusive 3D Multi–Detector Row CT Protocol

PURPOSE

To prospectively assess parenchymal, vascular, and biliary anatomy of potential living liver donors with an all-inclusive multi-detector row computed tomographic (CT) approach.

MATERIALS AND METHODS

A total of 250 potential living liver donors (112 women, 138 men; mean age, 37 years) underwent three-phase, dual-enhancement multi-detector row CT to delineate biliary, vascular, and parenchymal morphology according to an institutional review board-approved protocol. Informed consent was obtained from all subjects. For display of the biliary system, the first CT image set was collected after the infusion of a biliary contrast agent. CT angiography was subsequently performed, after automated injection of a conventional iodinated contrast agent, to display the arterial and portal-hepatic venous systems. All data sets were reconstructed in 1-mm sections. Data analysis was based on source images, multiplanar reconstructions, and three-dimensional postprocessing images; was performed in consensus by two radiologists; and was focused on the detection of biliary and vascular variants, exclusion of focal liver lesions, and determination of hepatic volumes. Preoperative findings were correlated with intraoperative findings (available in 62 subjects).

RESULTS

Technical failures were experienced in 10 of 250 examinations. Twenty-seven subjects had moderate adverse reactions related to the biliary contrast agent. Benign hepatic lesions were detected in 61 candidates; one candidate had a renal cell carcinoma. Underlying biliary and vascular anatomy was displayed at least to the second intrahepatic branch in all but seven patients. Detected anatomic variants involved the biliary (38.8%), arterial (40.0%), portal venous (21.4%), and hepatic venous (43.5%) systems. Correlation with intraoperative findings was excellent. Some biliary (n = 4), arterial (n = 5), portal venous (n = 1), and hepatic venous (n = 6) variants were missed or misinterpreted at initial reading of preoperative data; however, variants could be retrospectively depicted in all but one biliary case and one hepatic venous case.

CONCLUSION

The outlined three-phase, dual-enhancement multi-detector row CT protocol represents an all-inclusive approach to evaluate potential living liver donors in a single diagnostic step.

Variability of preoperatively determined hepatic volumes in potential living liver donors

RATIONALE AND OBJECTIVES

The aim of the study is to evaluate variability in hepatic volumes during the preoperative period in potential liver donors.

MATERIALS AND METHODS

Eight potential living liver donors underwent preoperative multirow-detector computed tomographic assessment of hepatic transplant volumes twice. Intraindividual delay between the two examinations range was 3-62 days (mean, 30.1 days). Liver volumes were determined in a blinded fashion by an experienced radiologist and a transplantation surgeon. Results were compared and correlated with time of data acquisition during the day.

RESULTS

Interobserver variability for assessments of liver volumes range was 6-32 mL (mean, 16 mL). Intraindividually, the difference between the two volume assessments ranged between -103 and +45 mL (mean, -19 mL), corresponding to percentages of alteration between -7.5% and +3.2%. There was no statistical correlation evident concerning volume alterations and specific time of data acquisition.

CONCLUSION

Neither time of data acquisition nor waiting period for the surgical procedure seems to affect the accuracy of liver volume calculation. Apparent volume variations likely are in the range of the method error of the applied technique.

Twenty cases of adult-to-adult living-related liver transplantation: single-center experience in Saudi Arabia

BACKGROUND

The deceased donor organ shortage has forced surgeons to implement innovations, including living-related liver transplantation (LRLT).

OBJECTIVE

To present the first 20 cases of adult LRLT in a single center in Saudi Arabia.

METHODS

From November 2000 to May 2004, we performed 20 cases of LRLT. Eighteen donors were men and 2 were women. Their median age was 27 years. Seventeen of the recipients were men and 3 were women of median age 55 years. One patient received combined liver and kidney grafts.

RESULTS

All cases had liver cirrhosis. Seven had hepatitis C; six, hepatitis B and C; three, hepatitis B; one, alcoholic cirrhosis; one, Bylar disease, one hepatic schistosomiasis, and one cryptogenic cirrhosis. Three cases had associated hepatocellular carcinomas. There was no donor mortality. In the recipients, the overall patient and graft survival was 85%. While 10 donors presented uneventful postoperative courses, 8 experienced minor complications and 2, major complications: biliary stricture and portal vein thrombosis. Recipients complications included biliary complications (35%), acute rejection (20%), hepatitis C reactivation (20%), hepatic vein stenosis (10%), hepatic artery stenosis (5%), and hepatocellular carcinoma recurrence (5%).

CONCLUSIONS

LRLT has become a standard option in adults with end-stage liver failure in our center.

Whole fetal liver transplantation--a new approach to cell therapy

We recently developed a novel rat model for liver repopulation, heterografting of microliver slices, aimed at overcoming the limitations inherent in both whole liver and hepatocyte transplantations. The aim of the present study was to evaluate the potential of whole fetal liver transplantations to survive and differentiate within the adult liver, using the adult liver slice transplantation model. Embryonic day 14 whole fetal livers from dipeptidyl peptidase IV+/+ wild-type Fischer 344 rats were transplanted into the livers of dipeptidyl peptidase IV-/- mutant rats. Adult hepatic markers, dipeptidyl peptidase IV, albumin, glycogen, and proliferation cell nuclear antigen- proliferation cell nuclear antigen (PCNA) were assessed in the transplanted liver tissue by immunohistochemistry. Two groups of 9 rats each were transplanted with 3 fetal livers per recipient. Two months later the rats were sacrificed and the markers were detected in the transplanted tissues. In conclusion, the results of this study raise the possibility that fetal liver transplantation could serve as a model for genetic metabolic liver diseases.

"All-in-one" imaging protocols for the evaluation of potential living liver donors: comparison of magnetic resonance imaging and multidetector computed tomography

In order to compare the performance of "all-in-one" magnetic resonance imaging (MRI) and "all-in-one" multidetector computed tomography (MDCT) in the preharvest evaluation 25 potential living donors underwent both MRI and MDCT. MRI was performed on a high-performance 1.5-T scanner, computed tomography (CT) on a 4-row multidetector-scanner. Both scan protocols included angiography of the arterial and venous hepatic systems. CT additionally included infusion of a biliary contrast agent. Data analysis was performed by 4 reviewers, based on source images, multiplanar reformats, and three-dimensional (3D) postprocessing. Determination of image quality was based on a 4-point image quality rating (IQR) scale, ranging from 1 = nondiagnostic to 4 = excellent. Preoperative and intraoperative (n = 13) findings were correlated. Magnetic resonance (MR) examinations were generally well tolerated. Within the CT scan, 2 candidates presented moderate adverse reaction to the biliary contrast agent. MRI and CT showed the same benign parenchymal lesions (IQR MR: 3.7; IQR CT: 3.4). Determination of liver volumes was easier based on CT (IQR MR: 3.3; IQR CT: 3.6). Magnetic resonance angiography (MRA) revealed 10 variants of the arterial liver supply (IQR: 3.0) and computed tomographic angiography (CTA) revealed 13 variants (IQR: 3.5). Magnetic resonance cholangiopancreatography (MRCP) identified 4 biliary variants (IQR: 1.3) and CT cholangiography identified 17 (IQR: 3.5). MRI and CT each showed 4 hepatic and portal venous variants (IQR MR: 3.4, CT: 2.8). CT and MR findings correlated well with intraoperative findings. In conclusion, both techniques proved to be efficient to evaluate potential living liver donors' anatomy in a single diagnostic step. The main advantage of CT lies in the ability to accurately assess the biliary anatomy.

Qualidade de vida do doador após transplante hepático intervivos

RACIONAL: A qualidade de vida do doador após transplante hepático intervivos ainda não foi avaliada em nosso meio. OBJETIVO: Avaliar a qualidade de vida do doador após transplante hepático intervivos. MÉTODOS: De um total de 300 transplantes hepáticos, 51 foram de doadores vivos. Doadores com seguimento menor do que 6 meses e os que não quiseram participar do estudo foram excluídos. Os doadores responderam a um questionário de 28 perguntas abordando os vários aspectos da doação, sendo também avaliados dados demográficos e clínicos dos mesmos. RESULTADOS: Trinta e sete doadores aceitaram participar do estudo. Destes, 32 eram parentes de primeiro ou de segundo grau do receptor. O esclarecimento sobre o caráter voluntário da doação foi adequado para todos pacientes. Apenas um (2%) não doaria novamente. A dor pós-operatória foi pior do que o esperado para 22 doadores (59%). O retorno às atividades normais ocorreu em menos de 3 meses para 21 doadores (57%). Vinte e um doadores (57%) tiveram perda financeira com a doação devido a gastos com medicamentos, exames, transporte ou perda de rendimentos. Trinta e três (89%) não tiveram modificação ou limitação na sua vida após a doação. Os aspectos mais negativos da doação foram a dor pós-operatória e a presença de cicatriz cirúrgica. A maioria das complicações pós-operatória foi resolvida com o tratamento clínico, mas complicações graves ou potencialmente fatais ocorreram em dois pacientes. CONCLUSÕES: A maioria dos doadores apresentou boa recuperação e retornou completamente as suas atividades normais poucos meses após a doação. O aspecto mais negativo da doação foi a dor pós-operatória.

Evolution of donor morbidity in living related liver transplantation: a single-center analysis of 165 cases

OBJECTIVE

During the last 14 years, living donor liver transplantation (LDLT) has evolved to an indispensable surgical strategy to minimize mortality of adult and pediatric patients awaiting transplantation. The crucial prerequisite to performing this procedure is a minimal morbidity and mortality risk to the healthy living donor. Little is known about the learning curve involved with this type of surgery.

PATIENTS AND METHODS

From January 1991 to August 2003, a total of 165 LDLTs were performed in our center. Of these, 135 were donations of the left-lateral lobe (LL, segments II and III), 3 were of the left lobe (L, segments II-IV), 3 were full-left lobes (FL, segments I-IV), and 24 were of the full-right lobe (FR, segments V-VIII). We divided the procedures into 3 periods: period 1 included the years 1991 to 1995 (LL, n = 49; L, n = 2; FR, n = 1), period 2 covered 1996 to 2000 (LL, n = 47), and period 3 covered 2001 to August 2003 (LL, n = 39; FR, n = 23; FL, n = 3; L, n = 1). Perioperative mortality and morbidity were assessed using a standardized classification. Length of stay in intensive care unit, postoperative hospital stay, laboratory results (bilirubin, INR, and LFTs), morbidity, and the different types of grafts in the 3 different periods were compared.

RESULTS

One early donor death was observed in period 1 (03/07/93, case 30; total mortality, 0.61.%). Since 1991, the perioperative morbidity has continually declined (53.8% vs. 23.4% vs. 9.2%). In period 1, 28 patients had 40 complications. In period 2, 11 patients had 12 complications, and in period 3, 6 patients had 9 complications. Within the first period, 1 donor underwent relaparotomy because of bile leakage. Postoperative hospital stay was 10 days, 7 days, and 6 days, respectively. Donation of the full right lobe, in comparison with that of the left lateral lobe, resulted in a significantly diminished liver function (bilirubin and INR) during the first 5 days after donation but did not increase morbidity. One donor from period 1 experienced late death caused by amyotrophic lateral sclerosis.

CONCLUSIONS

In a single center, morbidity after living liver donation strongly correlates to center experience. Despite the additional risks associated with temporary reduction of liver function, this experience enabled the team to bypass part of the learning curve when starting right lobe donation. Specific training of the surgical team and coaching by an experienced center should be implemented for centers offering this procedure to avoid the learning curve.

[Acute liver failure. Current aspects of diagnosis and therapy]

Disturbances of some partial liver functions, such as synthesis, excretion, or biotransformation of xenobiotics, are important for prognosis and ultimate survival in patients presenting with multiple organ dysfunction on the intesive care unit (ICU). The incidence of liver dysfunction is underestimated when traditional "static" measures such as serum-transaminases or bilirubin as opposed to "dynamic" tests, such as clearance tests, are used to diagnose liver dysfunction. Similar to the central role of the failing liver in MODS, extrahepatic complications, such as hepatorenal syndrome and brain edema develop in acute or fulminant hepatic failure and determine the prognosis of the patient. This is reflected in the required presence of hepatic encephalopathy in addition to hyperbilirubinemia and coagulopathy for the diagnosis of acute liver failure. In addition to these clinical signs, dynamic tests, such as indocyanine green clearance, which is available at the bed-side, are useful for the monitoring of perfusion and global liver function. In addition to specific and causal therapeutic interventions, e.g. N-acetylcysteine for paracetamol poisoning or termination of pregnancy for the HELLP-syndrome, new therapeutic measures, e.g. terlipressin/albumin or albumin dialysis are likely to improve the poor prognosis of acute-on-chronic liver failure. Nevertheless, liver transplantation remains the treatment of choice for fulminant hepatic failure when the expected survival is <20%.

Stem cell therapy of the liver--fusion or fiction?

Various stem cell populations have been described in distinct models of liver regeneration. This review provides an overview of these different stem cell populations aimed at unifying diverse views of liver stem cell biology. Embryonic stem cells, hemopoietic stem cells, mesenchymal stem cells, liver-derived hepatic stem cells, bone marrow-derived hepatic stem cells, and mature hepatocytes (as cells with stemlike properties) are considered separately. In so doing, we seek to clarify the nomenclature of putative liver stem cell types. Experiments that address the question of cellular fusion versus transdifferentiation as explanations for observed liver regeneration are highlighted. This review concludes with a series of open questions that should be addressed in the context of clinical liver disease before attempts at human therapeutic interventions.

One hundred in situ split-liver transplantations: a single-center experience

OBJECTIVE

To identify predictors of graft and recipient survival from a single-institution series of in situ split-liver transplantations and compare outcomes to living donor and whole organs for adults and children.

SUMMARY BACKGROUND DATA

Split-liver transplantation is a surgical technique that creates 2 allografts from a single cadaver donor. We have applied split-liver transplantation to all indications and categories of medical urgency for initial as well as retransplantation to expand the current donor pool and decrease reliance upon living donation.

METHODS

A retrospective analysis was conducted of 100 consecutive in situ split-liver transplantations yielding a left lateral segment and right trisegment graft that were performed at the University of California Los Angeles between 9/91 and 02/03. These 100 transplantations generated 190 allografts for transplantation into 105 children and 60 adults, with the sharing of 25 allografts among transplant centers across the United States. Outcomes and incidence of complications were compared with living donor and whole organ recipients receiving liver transplantation during the same time period with independent predictors of split-liver graft and recipient survival identified by multivariate analysis.

RESULTS

The incidence of biliary and vascular complications observed in recipients of left lateral segment grafts created by split-liver transplantation was not statistically different from recipients of left lateral segment grafts created from living donation or children receiving whole-organ grafts from pediatric donors. Kaplan-Meier survival estimations of left lateral segment graft and recipient survival also demonstrated no statistical difference among split-liver, living donor, and whole-organ recipients. Right trisegment grafts from split-liver transplantation demonstrated a 10% incidence of biliary and 7% incidence of vascular complications. Long-term graft function was excellent with patient and graft survival equal to 1086 recipients of cadaver whole-organ grafts from donors ages 10-40 years who underwent transplant operations during the same time period. Predictors of split-liver transplantation graft and recipient survival included United Network for Organ Sharing status at transplantation, indication, occurrence of a complication, donor creatinine, and donor length of hospitalization.

CONCLUSIONS

Split-liver transplantation is an effective mechanism for immediate expansion of the cadaver donor pool that can reduce dependence upon living donation in adults and children.