Partial left lateral segment transplant from a living donor

Understanding Local Hemodynamic Changes After Liver Transplant: Different Entities or Simply Different Sides to the Same Coin?

Liver transplantation is an extremely complex procedure performed in an extremely complex patient. With a successful technique and acceptable long-term survival, a new challenge arose: overcoming donor shortage. Thus, living donor liver transplant and other techniques were developed. Aiming for donor safety, many liver transplant units attempted to push the viable limits in terms of size, retrieving smaller and smaller grafts for adult recipients. With these smaller grafts came numerous problems, concepts, and definitions. The spotlight is now aimed at the mirage of hemodynamic changes derived from the recipients prior alterations. This article focuses on the numerous hemodynamic syndromes, their definitions, causes, and management and interconnection with each other. The aim is to aid the physician in their recognition and treatment to improve liver transplantation success.

Large for size in pediatrics liver transplant using left lateral segment grafts: A single center experience

BACKGROUND

There are still controversies in using the large left lateral segment in pediatrics LT, with the possibility of the problem of LFS grafts, and the use of monosegmental or reduced liver grafts in small infants. This study aimed to evaluate our experience with LFSG in pediatrics LT.

METHODS

A cohort retrospective analysis was conducted including pediatric recipients who underwent LT between January 2011 and October 2019. We compared recipients with GRWR ≥ 4% (LFS) vs GRWR < 4% as an average for size grafts.

RESULTS

There were 331 pediatric LT, 74 patients with GRWR ≥ 4%, and 257 patients with GRWR < 4%. In the group of LFS grafts, temporary abdominal closure by silicon patch was done in 39 patients (52.7%), 2 patients (2.7%) had postoperative HAT, 3 patients (4.1%) early PVT, 1 patient (1.3%) bile leak, and 3 patients (4.1%) had wound infection, with no significant difference in these complications between the 2 groups. In patients with LFS- grafts, the 1-, 3-, 5-, and 7-year patients survival rates were 94.6%, 91.7%, 91.7%, and 91.7%, respectively, while the survival rates in patients of the other group were 96.1%, 92.6%, 91.9%, and 91.9%, respectively, with no significant difference (p = .85).

CONCLUSION

Using LFS graft by left lateral segment in pediatric LT with potential delayed abdominal closure is a safe and feasible option with good outcomes and unnecessary need for graft reduction if performed by an experienced multidisciplinary team.

Short- and Long-Term Outcomes After Live-Donor Transplantation with Hyper-Reduced Liver Grafts in Low-Weight Pediatric Recipients

OBJECTIVE

To evaluate short- and long-term outcomes after live-donor liver transplantation (LT) with hyper-reduced grafts in low-weight pediatric recipients. LT is an established curative therapy for children with end-stage chronic liver disease or acute liver failure. A major problem in pediatric LT has been the lack of size-matched donor organs. The disadvantage of the use of large-for-size grafts is the insufficient tissue oxygenation and graft compression, which result in poor outcomes. The shortage of suitable donors is most notable in children under 10 kg. To overcome such obstacle, in situ hyper-reduced live-donor liver grafts have been introduced. Available articles in the literature are based on small samples and are deficient in long-term follow-up.

METHODS

A single-cohort, retrospective analysis was conducted including 59 pediatric patients under 10 kg who underwent hyper-reduced (in situ "a la carte" left lateral segment reduction) live-donor LT (LDLT) between February 1994 and February 2018.

RESULTS

The most frequent cause of liver failure was biliary atresia (70%). Median recipient weight was 8 kg. Vascular complications were confirmed in 15% of the sample, while 45% presented biliary complications. Median follow-up time was 40.3 months. Ten-year overall survival rate was 74%. Pediatric end-stage liver disease score > 23 was associated with a higher risk of post-operative complications.

CONCLUSION

LDLT can be undertaken in children with body weight < 10 kg achieving good results in high-volume centers by experienced surgeons.

Dorsal approach plus branch patch technique is the preferred method for liver transplanting small babies with monosegmental grafts

PURPOSE

When living donor liver transplantation (LDLT) is performed on small infant patients, the incidence of hepatic artery complications (HACs) is high. Here, we present a retrospective analysis that focuses on our surgical procedure for hepatic arterial reconstruction and the outcomes of monosegmental LDLT.

METHODS

Of the 275 patients who underwent LDLT between May 2001 and December 2015, 13 patients (4.7 %) underwent monosegmental LDLT. Hepatic artery reconstruction was performed under a microscope. The size discrepancy between the graft and the recipient's abdominal cavity was defined as the graft to recipient distance ratio (GRDR) between the left hepatic vein and the portal vein (PV) bifurcation on a preoperative computed tomography scan. HACs were defined as hepatic arterial hypoperfusion.

RESULTS

Recipient hepatic arteries were selected for the branch patch technique in five cases (38.5 %), and the diameter was 2.2 ± 0.6 mm. The anastomotic approaches selected were the dorsal position of the PV in seven cases (53.8 %) and the ventral position in six, and the GRDRs were 2.8 ± 0.4 and 1.9 ± 0.5, respectively (p = 0.012). The incidence rate of HACs caused by external factors, such as compression or inflammation around the anastomotic site, was significantly higher in monosegmental than in non-monosegmental graft recipients (15.4 vs. 1.1 %, p < 0.001).

CONCLUSION

Although monosegmental graft recipients experienced HACs caused by external factors around the anastomotic field, hepatic arterial reconstruction could be safely performed. Important components of successful hepatic arterial reconstructions include the employment of the branch patch technique and the selection of the dorsal approach.

Technical aspects for live-donor organ procurement for liver, kidney, pancreas, and intestine

PURPOSE OF REVIEW

This article reviews current strategies for living-donor organ procurement in liver, kidney, pancreas, and intestinal transplant.

RECENT FINDINGS

Here we summarize current open and laparoscopic approaches to living donation of abdominal organs.

SUMMARY

Living donation strategies expand the organ pool in the setting of a significant organ shortage.

Selection of living donor liver grafts for patients weighing 6kg or less

In the field of pediatric living donor liver transplantation (LDLT), physicians sometimes must reduce the volume of left lateral segment (LLS) grafts to prevent large-for-size syndrome. There are 2 established methods for decreasing the size of an LLS graft: the use of a segment 2 (S2) monosegment graft and the use of a reduced LLS graft. However, no procedure for selecting the proper graft type has been established. In this study, we conducted a retrospective investigation of LDLT and examined the strategy of graft selection for patients weighing ≤6 kg. LDLT was conducted 225 times between May 2001 and December 2012, and 15 of the procedures were performed in patients weighing ≤6 kg. We selected S2 monosegment grafts and reduced LLS grafts if the preoperative computed tomography (CT)-volumetry value of the LLS graft was >5% and 4% to 5% of the graft/recipient weight ratio, respectively. We used LLS grafts in 7 recipients, S2 monosegment grafts in 4 recipients, reduced S2 monosegment grafts in 3 recipients, and a reduced LLS graft in 1 recipient. The reduction rate of S2 monosegment grafts for use as LLS grafts was 48.3%. The overall recipient and graft survival rates were both 93.3%, and 1 patient died of a brain hemorrhage. Major surgical complications included hepatic artery thrombosis in 2 recipients, bilioenteric anastomotic strictures in 2 recipients, and portal vein thrombosis in 1 recipient. In conclusion, our graft selection strategy based on preoperative CT-volumetry is highly useful in patients weighing ≤6 kg. S2 monosegment grafts are effective and safe in very small infants particularly neonates.

Liver transplantation in Latin America: the state-of-the-art and future trends

We reviewed the current status of liver transplantation in Latin America. We used data from the Latin American and Caribbean Transplant Society and national organizations and societies, as well as information obtained from local transplant leaders. Latin America has a population of 589 million (8.5% of world population) and more than 2,500 liver transplantations are performed yearly (17% of world activity), resulting in 4.4 liver transplants per million people (pmp) per year. The number of liver transplantations grows at 6% per year in the region, particularly in Brazil. The top liver transplant rates were found in Argentina (10.4 pmp), Brazil (8.4 pmp), and Uruguay (5.5 pmp). The state of liver transplantation in some countries rivals those in developed countries. Model for End-Stage Liver Disease-based allocation, split, domino, and living-donor adult and pediatric transplantations are now routinely performed with outcomes comparable to those in advanced economies. In contrast, liver transplantation is not performed in 35% of Latin American countries and lags adequate resources in many others. The lack of adequate financial coverage, education, and organization is still the main limiting factor in the development of liver transplantation in Latin America. The liver transplant community in the region should push health care leaders and authorities to comply with the Madrid and Istambul resolutions on organ donation and transplantation. It must pursue fiercely the development of registries to advance the science and quality control of liver transplant activities in Latin America.

Liver graft volumetric changes after living donor liver transplantation with segment 2 graft for small infants

LT for small infants weighing <5 kg with liver failure might require innovative techniques for size reduction and transplantation of small grafts to avoid large-for-size graft, but little is known about post-transplant graft volumetric changes. Five of 172 children who underwent LDLT received monosegment or reduced monosegment grafts using a modified Couinaud's segment II (S2) graft for LDLT. Serial CT was used to evaluate the changes in the GV and other factors before LDLT and one and three months after LDLT. The shape of these grafts was classified into an OL type and an LL type. The GV increased in all patients one month after LDLT, whereas the GV decreased three months after LDLT in OL in comparison with one month after LDLT. The GRWR of the OL type has tended to decrease at three months, whereas the LL type showed a continuous increase with time, but finally they had adapted graft size for their body size. In conclusion, the volume of S2 grafts after LDLT had unique changes toward the ideal volume for the child weight when they received the appropriate liver volume.

Transplantation with hyper-reduced liver grafts in children under 10 kg of weight

BACKGROUND

We had previously described a left lateral segment hyper-reduction technique capable of sizing the graft according to the volume of the abdominal cavity of the recipient.

AIM

The purpose of our study was to evaluate our 14-year live-donor liver transplantation experience with in situ graft hyper-reduction in children under 10 kg of weight.

PATIENTS AND METHODS

Between January 1997 and May 2011, we performed 881 liver transplants. Two hundred and seventy-seven (n = 277) involved pediatric recipients, of which 102 (37 %) were from live donors. Thirty-five (n = 35) patients under 10 kg of weight underwent hyper-reduced living donor liver transplants. There were 21 females (60 %) and 14 males (40 %), with a median age of 12 months (range 3-23) and a median weight of 7.7 kg (range 5.6-10).

RESULTS

Median operative time was 350 min (range 180-510). Median cold ischemia time was 180 min (range 60-300). Twenty-six (n = 26) patients required intraoperative transfusion of blood products. There were 49 postoperative complications involving 26 patients (74 % morbidity rate). One-, 3-, and 5-year survival rates were 87, 79, and 74 %, respectively. Twenty-eight patients are currently alive.

CONCLUSIONS

Hyper-reduced grafts provide an alternative approach for low-weight pediatric recipients. The relatively high immediate postoperative morbidity could be related to the complexity of these patients.

Implications for the usage of the left lateral liver graft for infants ≤10 kg, irrespective of a large-for-size situation--are monosegmental grafts redundant?

Organ donor shortage for infant liver transplant recipients has lead to an increase in splitting and living donation. For cases in which even transplantation of the left lateral graft (Couinaud's segments II + III) results in a "large for size situation" with an estimated graft body weight ratio (GBWR) of >4%, monosegmental liver transplantation was developed. This, however, bears complications because of greater parenchymal surface and suboptimal vascular flow. We exclusively use the left lateral graft from living donors or split grafts. Temporary abdominal closure is attempted in cases of increased pressure. We report of 41 pediatric transplants in 38 children ≤10 kg. Within this group, there were 23 cases with a GBWR of ≥4, and 15 cases with a GBWR <4. There was no statistical difference in vascular or biliary complications. Despite a more frequent rate of temporary abdominal closure, we did not find a higher rate of intra-abdominal infections. Overall, patient and graft survival was excellent in both groups (one death, three re-transplants). We noticed, however, that the ventro-dorsal diameter of the graft appears to be more relevant to potential graft necrosis than the actual graft size. In conclusion, the usage of monosegmental grafts seems unnecessary if transplantation of left lateral grafts is performed by an experienced multidisciplinary team, and temporary abdominal closure is favored in cases of increased abdominal pressure.

Living donor liver transplantation for neonatal hemochromatosis using non-anatomically resected segments II and III: a case report

INTRODUCTION

Neonatal hemochromatosis is the most common cause of liver failure and liver transplantation in the newborn. The size of the infant determines the liver volume that can be transplanted safely without incurring complications arising from a large graft. Transplantation of monosegments II or III is a standard method for the newborns with liver failure.

CASE PRESENTATION

A three-week old African-American male neonate was diagnosed with acute liver failure secondary to neonatal hemochromatosis. Living-related liver transplantation was considered after the failure of intensive medical therapy. Intra-operatively a non-anatomical resection and transplantation of segments II and III was performed successfully. The boy is growing normally two years after the transplantation.

CONCLUSION

Non-anatomical resection and transplantation of liver segments II and III is preferred to the transplantation of anatomically resected monosegements, especially when the left lobe is thin and flat. It allows the use of a reduced-size donor liver with intact hilar structures and outflow veins. In an emergency, living-related liver transplantation should be offered to infants with liver failure secondary to neonatal hemochromatosis who fail to respond to medical treatment.

Living donor liver transplantation for neonates using segment 2 monosubsegment graft

The prognosis of liver transplantation for neonates with fulminant hepatic failure (FHF) continues to be extremely poor, especially in patients whose body weight is less than 3 kg. To address this problem, we have developed a safe living donor liver transplantation (LDLT) modality for neonates. We performed LDLTs with segment 2 monosubsegment (S2) grafts for three neonatal FHF. The recipient age and body weight at LDLT were 13-27 days, 2.59-2.84 kg, respectively. S2 or reduced S2 grafts (93-98 g) obtained from their fathers were implanted using temporary portacaval shunt. The recipient portal vein was reconstructed at a more distal site, such as the umbilical portion, to have the graft liver move freely during hepatic artery (HA) reconstruction. The recipient operation time and bleeding were 11 h 58 min-15 h 27 min and 200-395 mL, respectively. The graft-to-recipient weight ratio was 3.3-3.8% and primary abdominal wall closure was possible in all cases. Although hepatic artery thrombosis occurred in one case, all cases survived with normal growth. Emergency LDLT with S2 grafts weighing less than 100 g can save neonates with FHF whose body weight is less than 3 kg. This LDLT modality using S2 grafts could become a new option for neonates and very small infants requiring LT.

Model for end-stage liver disease-based allocation system for liver transplantation in Argentina: does it work outside the United States?

BACKGROUND

In July 2005, Argentina was the first country after the United States to adopt the MELD system. The purpose of the present study was to analyse the impact of this new system on the adult liver waiting list (WL).

METHODS

Between 2005 and 2009, 1773 adult patients were listed for liver transplantation: 150 emergencies and 1623 electives. Elective patients were categorized using the MELD system. A prospective database was used to analyse mortality and probability to be transplanted (PTBT) on the WL.

RESULTS

The waiting time increased inversely with the MELD score and PTBT positively correlated with MELD score. With scores >/= 18 the PTBT remained over 50%. However, the largest MELD subgroup with <10 points (n = 433) had the lower PTBT (3%). In contrast, patients with T(2) hepatocellular carcinoma benefited excessively with the highest PTBT (84.2%) and the lowest mortality rate (5.4%). The WL mortality increased after MELD adoption (10% vs. 14.8% vs. P < 0.01). Patients with <10 MELD points had >fourfold probability of dying on the WL than PTBT (14.3% vs. 3%; P < 0.0001).

CONCLUSIONS

After MELD implementation, WL mortality increased and most patients who died had a low MELD score. A comprehensive revision of the MELD system must be performed to include cultural and socio-economical variables that could affect each country individually.

The reduced left lateral segment in pediatric liver transplantation: an alternative to the monosegment graft

Tailoring graft size to small paediatric recipients is a challenge. We have developed a reduced left lateral segment as an alternative to monosegment transplantation for small size recipients. Since November 2000, 89 children have been transplanted with 100 deceased donor liver grafts in our unit. Our median patient and graft survival is 89% and 88% respectively. Four of these cases were performed using a new technique of creating a small donor graft by reducing the left lateral segment. The median weight of the reduced liver graft was 264 g (range: 165-390 g). The median blood transfusion requirement was 101 mL/kg body weight (range 69-167 mL/kg). The median values of peak ALT were 1473 IU/L, INR 2.2 and bilirubin 293 micromol/L in the first two wk following surgery. One neonatal recipient died five days after transplantation from a massive intracranial haemorrhage despite satisfactory graft function. Another recipient with excellent graft function died 10 months later from primary pulmonary hypertension and secondary cardiac failure. Hepatic artery thrombosis occurred in one patient with successful revascularization but he was retransplanted three months later for chronic rejection. No biliary or venous outflow complications occurred in this group. This technique of reduced left lateral segment liver transplantation is an alternative to the monosegment graft and allows small recipients to be successfully transplanted with few technical complications related to graft preparation.

Living donor liver transplantation for children in Brazil weighing less than 10 kilograms

Infants with end-stage liver disease represent a treatment challenge. Living donor liver transplantation (LDLT) is the only option for timely liver transplantation in many areas of the world, adding to the technical difficulties of the procedure. Factors that affect morbidity and mortality can now be determined, which opens a new era for improvement. We have accumulated an 11-year experience with LDLT for children weighing<10 kg. From October 1995 to October 2006, a total of 222 LDLT in patients<18 years of age were performed; 129 primary LDLT and 7 retransplants (4 LDLT and 3 deceased donor grafts) were performed in 129 infants weighing<10 kg. Forty-seven patients received grafts with graft-to-recipient weight ratio (GRWR) of >4%. Two patients received monosegmental grafts, and 2 patients underwent delayed abdominal wall closure. Portal vein thrombosis occurred in 5.4% of the patients, hepatic artery thrombosis in 3.1%, and both in 1.5%. Among several variables studied, only the bilirubin level at the time of transplantation was associated with increased risk of death (P=0.009). Grafts with GRWR>4% had no negative effect on patient survival. There were 7 retransplants, and 4 patients received a second parental LDLT. Patient survival rates at 1, 3, and 10 years after transplantation were 88.8%, 84.7%, and 82% for all children, and 87.5%, 84.9%, and 84.9% for infants weighing<10 kg. LDLT has results comparable to other modalities of liver transplantation in infants. Monosegment grafts were rarely required in this series, although they may be necessary in patients with lower body weight.

Living donor liver transplantation with reduced monosegments for neonates and small infants

BACKGROUND

In pediatric living donor liver transplantation, left lateral segment or monosegmental graft is used to overcome size discrepancies between adult donors and pediatric recipients. For neonates and extremely small infants, however, problems related to large-for-size graft are sometimes encountered even when using such grafts. The reduced monosegmental graft, in which the caudal part of the monosegmental graft is resected, has been introduced to address this problem.

METHODS

Of 566 children who underwent transplant between June 1990 and September 2004, reduced monosegment living donor liver transplants were used for nine patients (median age, 144 days; median weight, 4.1 kg). This technique was used for infants with estimated graft-to-recipient weight ratio (GRWR) > or =4.0% when using the left lateral segment.

RESULTS

Graft and patient survival was 66.7%. GRWR was reduced from 7.45+/-2.70% to 3.39+/-0.89% using this modification. Transaminase levels at days 1 and 2 after transplantation were significantly higher in reduced monosegmental transplantation than in left lateral segmental transplantation. Hepatic artery thrombosis and portal vein thrombosis were observed in one case each.

CONCLUSION

Reduced monosegmental living donor liver transplantation represents a feasible option for neonates and extremely small infants with liver failure.

Liver transplantation with monosegments. Technical aspects and outcome: a meta-analysis

The shortage of organ donors for low-weight liver transplant recipients, especially small children, has led to the development of new surgical techniques to increase the donor pool. Almost all of these techniques use the left lateral segment (Couinaud's segments II and III), but even this graft could be too large for children under 10 kg, and further reduction could be necessary. Few articles address the issue of monosegmental liver transplantation. Available articles are with small sample sizes or even case reports, which makes it difficult to draw conclusions about indication and outcome for monosegmental grafts. A search of the MEDLINE databases using the terms "Liver Transplantation" and "Monosegmental" or "Monosegments" limited to title or abstract with publication in the English language was conducted. The data from each study were selected and analyzed, regarding donor status (living or cadaveric), donor weight, surgical techniques used in left lateral further reduction, recipient indication for liver transplantation, age and recipient weight, graft-to-recipient body weight ratio, segment utilized, type of abdominal closure, postoperative complications, and survival. Seven publications were identified from 1995 to 2004 and fulfilled the criteria. A total of 27 pediatric patients who received a monosegment transplant were identified, median age 211 days (range, 27 to 454 days) and median weight 4.6 kg (range, 2.45 to 7.4 kg). Segment III was utilized in 21 (78%) and segment II in 6 (22%). Patient survival was 85.2%. In conclusion, monosegment liver transplantation appears to be a satisfactory option for infants weighing less than 10 kg who require a liver transplant.

Liver transplantation with monosegment from a living donor

The shortage of organ donors for low-weight liver transplant recipients, especially for small children, has led to the development of new surgical techniques to increase the donor pool. Almost all of these techniques use the left lateral segment (Couinaud's segments II and III), but even this graft could be too large for children under 10 kg. We report here the case of an 8-month-old boy, weighing 6.1 kg, who received a monosegmental graft (segment III) from his grandmother weighing 68 kg. The graft was reduced at the donor surgery, before clamping of the vessels. The donor was discharged on the fourth post-operative day; the recipient had an uneventful post-operative period and was discharged after 22 days.

The effect of liver graft-body weight ratio on the core temperature of pediatric patients during liver transplantation

The left lateral segment of the liver from an adult living donor sometimes is relatively too large for a small pediatric recipient. It currently is unknown whether a high graft-recipient body weight ratio (GRWR) has a significant effect on core temperature during the anhepatic and reperfusion phases of living donor liver transplantation (LDLT). Seventy-two pediatric patients undergoing LDLT were divided into two groups according to body weight. Group I (GI) consisted of patients with a body weight greater than 10 kg, and group II (GII), less than 10 kg. Core temperature, measured as nasopharyngeal temperature (NT), was compared between groups at induction of anesthesia, hourly during the following 6 hours, as the lowest core temperature at the anhepatic phase, 5 and 30 minutes after reperfusion, and the last 2 hours before the end of the operation. Mild hypothermia of 35.8 degrees C +/- 0.7 degrees C and 35.9 degrees C +/- 0.4 degrees C for GI and GII was noted after induction of anesthesia, respectively; this increased +/- 1 degrees C in the following 6 hours. In the anhepatic and reperfusion phases, a sudden and significant decrease in NT was observed in both groups. This decrease in NT was significantly greater in GII than GI. In conclusion, a sudden decrease in core temperature was observed during the anhepatic and reperfusion phases of LDLT in pediatric patients, likely caused by placement of the cold liver graft, which is flushed with 4 degrees C lactated Ringer's solution during vessel reconstruction, in the anhepatic phase and return of venous blood through the cold preserved liver in the reperfusion phase. Core temperatures of pediatric patients with a body weight less than 10 kg in GII, who received grafts with a high GRWR, were more affected than those in GI.

Preoperative evaluation of the entire hepatic vasculature in living liver donors with use of contrast-enhanced MR angiography and true fast imaging with steady-state precession

PURPOSE

To preoperatively assess the entire hepatic vasculature in living related liver donors with use of a combination of contrast material-enhanced magnetic resonance (MR) angiography and true fast imaging with steady-state precession (FISP).

MATERIALS AND METHODS

Twenty-five living potential liver donors were examined preoperatively on a 1.5T Siemens Sonata system. Twenty-four underwent surgery and two had catheter angiography performed to delineate complex anatomy. Contiguous 5-mm-thick, sub-second true FISP images of the liver were initially obtained during breath-holding in axial and coronal planes (repetition time [TR]/echo time [TE], 3.2/1.6; flip angle, 70 degrees ). MR angiography was performed with use of a three-dimensional (3D) gradient-echo fast low-angle shot (FLASH) pulse sequence (TR/TE, 3.0/1.2; flip angle, 25 degrees ), with 40 mL of Gadolinium DTPA injected at a rate of 2 mL/sec. One precontrast and two postcontrast coronal 3D volumes were acquired, each in a 20-second breath-hold, and two subtracted 3D sets were calculated. Arterial anatomy was assessed with use of maximum-intensity projection, volume rendering, and multiplanar reformatting algorithms. Hepatic and portal venous anatomy was evaluated with use of the true FISP images and the venous phase of the MR angiogram. Visualization of hepatic arterial branches was noted. Visualization of portal vein branches was scored on a scale of 0-5. The presence of anatomic variants was noted. Vascular anatomy was confirmed at the time of surgery and at catheter angiography.

RESULTS

Segmental branch vessels were visualized on MR angiography in the majority of cases. The segment four branch was identified in 96% patients. Variant arterial anatomy was seen in 50% of patients. MR angiography detected 10 of 11 arterial variants found at surgery and angiography. Visualization of portal vein branches was generally higher with true FISP compared to MR angiography. Twenty-four percent of patients had variant portal venous anatomy. Caudal hepatic veins were identified in 60% of patients, of which eight were significant (>5 mm). Hepatic and portal venous anatomy was accurately predicted by true FISP and MR angiography in all patients who went on to undergo surgery.

CONCLUSION

Preoperative imaging with use of a combination of contrast-enhanced MR angiography and true FISP provides a comprehensive assessment of the entire hepatic vasculature in living liver donors.

Recent advances in pediatric liver transplantation

Pediatric liver transplantation has matured into a well-established, highly successful treatment for advanced pediatric liver disease. Recent 1-year success rates range from 85% to 95%. This unprecedented achievement is the result of careful selection criteria and optimal timing of transplantation, technical advances in surgical technique, and improved treatment following transplant. This report highlights many recent published findings representing advances that have led to current successful approaches.

Liver transplantation. Living donor, hepatocyte, and xenotransplantation

Liver transplantation is now accepted as effective therapy in the treatment of acute and chronic hepatic failure. Improvements in surgical techniques and immune suppression have led to 5-year survival rates that exceed 70% in most centers. The success of transplantation has led to a dramatic increase in the number of candidates to over 14,000 places on the national waiting list. While the number of patients in need of transplantation increases, there has been little growth in the supply of available cadaveric organs, resulting in an organ shortage crisis. With waiting times often exceeding 1 to 2 years, the waiting list mortality now exceeds 10% in most regions. Several novel approaches have been developed to address the growing disparity between the limited supply and excessive demand for suitable organs.

From living related to in-situ split liver transplantation: how to reduce waiting-list mortality

The insufficient number of suitable cadaveric organs for pediatric recipients is the cause of high pretransplant mortality rates and long waiting times. With the introduction of split and living related liver transplantation, the waiting list mortality rate has dropped from greater than 15% to less than 5% and children are transplanted more rapidly. A 5-year patient and graft survival rate of greater than 80% has been obtained in those centers where split and living related liver transplantations are routinely performed. The data analyzed in this paper show that the only current solution to cadaveric organ shortage is a 'multimodal' approach, where whole liver cadaveric transplantation is associated with split and living related liver transplantation.