Monosegment Grafts Research Articles

Living donor liver transplantation with hyperreduced segment II monosegment graft for an infant weighing 3 kilograms

Living donor liver transplantation with hyperreduced segment II monosegment graft for an infant weighing 3 kilograms

Pediatric liver transplantation using hyper-reduced left lateral section and monosegment graft for infant patients: A collective review of Korean experience

Pediatric liver transplantation using hyper-reduced left lateral section and monosegment graft for infant patients: A collective review of Korean experience

Impact of Monosegment Graft Use for Infants in Pediatric Living Donor Liver Transplantation

Left lateral segment grafts are generally used for very young pediatric patients undergoing living donor liver transplantation (LDLT). Recently, graft reduction techniques were developed for LDLT. Monosegment grafting has been used in newborns. The aim of this study was to determine the usefulness of monosegment grafting for infants. Recipients <2 years of age who underwent LDLT with a monosegment graft between 2010 and 2020 were gathered. Parents comprised all LDLT donors. A segment 2 monosegment graft was resected as a graft from the donor. Standard liver volume (SLV) was estimated using Urata's equation. Graft type, graft weight (GW), and native liver weight were assessed. Eight patients were included in the study. Original diseases consisted of biliary atresia (n=6) and fulminant hepatitis (n=2). Final graft type included monosegment (n=5) and reduced monosegment (n=3). Median final GW/body weight after reduction was 3% (range, 2%-3.4%). Median native liver weight/SLV was 134% except in patients with fulminant hepatitis. Median pre-reduction graft volume (GV)/estimated GV was 113% (range, 60%-208%). Median pre-reduction GV/SLV of monosegment grafts that required reduction (n=3) was 109% (range, 106%-121%). Median final reduced graft GV/SLV was 80% (range, 74%-91%). Complications due to large-for-size grafts were not observed. One case of bile leakage due to graft reduction occurred as a complication. Grafts were functioning well with the exception of one graft loss due to antibody-mediated rejection. Estimated GV in infants varies widely. Monosegment grafting can be useful for infants as well as newborns.

Monosegment Liver Allografts for Liver Transplantation in Infants Weighing Less Than 6 kg: An Initial Indian Experience

BackgroundLiving donor liver transplantation in small infants is a significant challenge. Liver allografts from adults may be large in size. This is accompanied by problems of graft perfusion, dysfunction, and the inability to achieve primary closure of the abdomen. Monosegment grafts are a way to address these issues. MethodsTwo recipients in our cohort weighed less then 6 kg. The prospective left lateral segments from their donors were large for size. Therefore, monosegment 2 liver grafts were harvested. Data regarding the preoperative, intraoperative, and postoperative events in the donor and the recipient were recorded. ResultsWe were able to achieve significant reduction in the sizes of the grafts harvested. The donors underwent surgery and hospital stay uneventfully. The recipients had normal graft perfusion and no graft dysfunction, and we could achieve primary abdominal closure. One recipient had self-limiting bile leak postoperatively. ConclusionsMonosegment 2 liver allografts are safe and effective for use in living donor liver transplantation in small infants weighing less than 6 kg.

Segmental branching pattern of the left portal vein: Anatomical characteristics and clinical implications

The existing knowledge on anatomy of segmental branches of left portal vein (LPV) is limited. This study aims to describe the surgical anatomy and variations of LPV and its segmental branching pattern. Forty fresh cadaveric liver dissections were performed. The dissection of LPV was carried out from its emergence at the level of the portal vein bifurcation to its segmental branches penetrating the left hemiliver. LPV characteristics, the number, and situation of its segmental branches were recorded. LPV comprises two portions: a 28 ± 6.7 mm-long transverse portion (TPLPV) and a 34.9 ± 4.4 mm-long umbilical portion (UPLPV). Mean number of LPV branches to segments I, II, III, and IV was 2 ± 1 (1-6), 2 ± 1 (1-4), 2 ± 1 (1-5), and 8 ± 2 (4-14), respectively. A single large vein supplied segment II in 90% of the cases. Segment III constantly had one vein arising from the left horn of UPLPV with mean diameter of 5.9 ± 1.6 mm. Most of the veins to segment IV took origin from the right horn of UPLPV with a mean number of 5 ± 2 (2-8). Segmental veins arising from UPLPV and TPLPV and supplying segment IV were present in 90 and 45% of the cases respectively. Segmental veins arising from LPV are often multiple and variable in position. Detailed knowledge of these veins is mandatory in order successfully perform anatomical liver resections or monosegment graft harvest for pediatric liver transplantation. Clin. Anat. 31: 1122-1128, 2017. © 2017 Wiley Periodicals, Inc.

Living-Donor Liver Transplantation Using Segment 2 Monosegment Graft: A Single-Center Experience

BackgroundIn small infants, left lateral segment grafts are sometimes too large to overcome the problems of large-for-size grafts in the abdominal compartment. To address this problem, we have developed a safe living donor graftectomy for neonates, a so-called “S2 monosegment graft” to minimize graft thickness. We reviewed our single-center experience to evaluate the feasibility of this technique for reducing graft size. MethodsEleven living-donor liver transplants using S2 monosegment grafts were performed between October 2008 and September 2014 at our institution. Medical records of both donors and recipients were reviewed and data collected retrospectively. ResultsThe mean age of recipients at the time of transplantation was 125.3 days, including 3 neonates. The average S2 monosegment graft weight was 127.4 g, and the graft-to-recipient body weight ratio was successfully reduced to 3.5%. The graft livers were reduced to 4.1 cm in thickness. Two recipients with grafts larger than 5 cm could not undergo primary abdominal closure. Portal vein stenosis and biliary stenosis was observed in 1 recipient, and hepatic artery complications were seen in 2 recipients; the clinical course for all donors were uneventful. Liver regeneration was seen in every patient. The graft and patient 1-year survival rate was 100%. ConclusionsLiving-donor liver transplantation using S2 monosegment grafts offers a safe and useful option for treating smaller infants. Here, we introduce our method of S2 monosegment graft emphasizing the donor harvest and graft thickness.

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.

Pediatric Liver Transplantation Using Reduced and Hyper-Reduced Left Lateral Segment Grafts: A 10-Year Single-Center Experience

Few studies have examined the long-term outcomes and prognostic factors associated with pediatric living living-donor liver transplantation (LDLT) using reduced and hyper-reduced left lateral segment grafts. We conducted a retrospective, single-center assessment of the outcomes of this procedure, as well as clinical factors that influenced graft and patient survival. Between September 2000 and December 2009, 49 patients (median age: 7 months, weight: 5.45 kg) underwent LDLT using reduced (partial left lateral segment; n = 5, monosegment; n = 26), or hyper-reduced (reduced monosegment grafts; n = 18) left lateral segment grafts. In all cases, the estimated graft-to-recipient body weight ratio of the left lateral segment was more than 4%, as assessed by preoperative computed tomography volumetry, and therefore further reduction was required. A hepatic artery thrombosis occurred in two patients (4.1%). Portal venous complications occurred in eight patients (16.3%). The overall patient survival rate at 1, 3 and 10 years after LDLT were 83.7%, 81.4% and 78.9%, respectively. Multivariate analysis revealed that recipient age of less than 2 months and warm ischemic time of more than 40 min affected patient survival. Pediatric LDLT using reduced and hyper-reduced left lateral segment grafts appears to be a feasible option with acceptable graft survival and vascular complication rates.

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.

Graft type in pediatric liver transplantation

To review the literature on graft type in pediatric liver transplantation, with a specific focus on publications since 2010. Due to the limited availability of whole livers for transplantation, the majority of pediatric patients will receive a technical variant graft (live donor, reduced, split). Although the outcomes of these grafts may be inferior to whole organs, the detrimental impact needs to be balanced with the impact of technical variants on improved access and survival to transplantation. Vigilance in detecting and managing posttransplant complications is critical in ensuring the optimal outcome. Infants under 5 kg pose a particular challenge in terms of graft selection with hyperreduced and monosegment grafts proposed for this population. Grafts from donors after cardiac death show promise in expanding the donor pool. However, experience in pediatric patients with these grafts is quite limited, particularly in young children who form the majority of pediatric transplant recipients. Auxiliary transplantation is proposed as a strategy for children presenting with fulminant hepatic failure and for children with metabolic diseases. The majority of children will receive a technical variant graft, with graft choice being largely determined by organ availability.

Long-Term Outcomes After Living-Donor Liver Transplantation for Alagille Syndrome: A Single Center 20-Year Experience in Japan

Long-Term Outcomes After Living-Donor Liver Transplantation for Alagille Syndrome: A Single Center 20-Year Experience in Japan

Liver transplantation in children with hyper-reduced grafts - A single-center experience

In small infants and babies who receive split or living-related adult left lateral segmental liver grafts, further reduction (hyper-reduction) of the graft may be necessary to optimize the size of the graft for the child. We report our experience with hyper-reduction of adult left lateral segment grafts in nine children. A retrospective review of the medical records of children who received hyper-reduced grafts at the Children's Hospital at Westmead, Australia was performed. Of 215 liver transplants performed on 186 children between 1986 and May 2009, 147 were reduced grafts. Nine grafts were further reduced (hyper-reduced) after an on-table assessment of graft size relative to the available abdominal space was made. Mean graft size reduction was by 30%. The pledgetted technique of resection was used in four patients. All required delayed closure of the abdomen, and in three patients, fascial closure was not possible and a Surgisis patch (Cook Surgical International, West Lafayette, IN, USA) was placed to augment the abdominal capacity. Two children had hepatic artery thrombosis. One was successfully thrombectomized. In the other, technical problems with the donor liver contributed to death 10 days post-transplant. Two bile leaks, one from the cut surface and the other at the anastomotic site, were oversewn at the time of abdominal closure. On follow-up (median 33 months), two developed biliary strictures requiring dilatation. Hyper-reduction of segmental grafts can be safely performed when needed. In view of its versatility, it may be preferable to hyper-reduce a graft rather than use a monosegment graft. Comparable long-term results are possible. The pledgetted technique of resection is easy, quick, and safe. The fact that it can be performed after revascularization with minimal blood loss adds great flexibility to this technically challenging procedure.

Forty Years of Liver Transplantation in the United Kingdom—Reflections on Challenges and Achievements

In this contribution to the celebration of 40 years of liver transplantation in the United Kingdom, early successes and more often disappointments are recounted along with the many challenges that had to be overcome. Acceptance of brainstem criteria for death, formulation of the University of Wisconsin preservation solution, better understanding of the vasculature of the biliary tract, and the discovery of new immunosuppressive agents each in turn had an influence in improving survival. Realization that diseases could recur in the transplanted liver represented another major area of clinical documentation, and for the surgeons, there were the added challenges of double and triple transplants as well as liver splits and monosegment grafts in pediatric recipients.

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.

Vascular reconstruction and complications in living donor liver transplantation in infants weighing less than 6 kilograms: The Kyoto experience

Smaller-size infants undergoing living-donor liver transplantation (LDLT) are at increased risks of vascular complications because of their smaller vascular structures in addition to vascular pedicles of insufficient length for reconstruction. Out of 585 child patients transplanted between June 1990 and March 2005, 64 (10%) weighing less than 6 kg underwent 65 LDLTs. Median age and weight were 6.9 months (range: 1-16 months) and 5 kg (range: 2.8-5.9 kg), respectively. Forty-five lateral segment, 12 monosegment, and 8 reduced monosegment grafts were adopted, and median graft-to-recipient weight ratio was 4.4% (range: 2.3-9.7). Outflow obstruction occurred in only 1 patient (1.5%). Portal vein complication occurred in 9 (14%) including 5 with portal vein thrombosis. Hepatic artery thrombosis (HAT) occurred in 5 (7.7%). Patient and graft survivals were 73% and 72% at 1 yr, and 69% and 68% at 5 yr after LDLT, respectively. Thirteen of 22 grafts (58%) lost during the follow-up period occurred within the first 3 months posttransplantation. Overall graft survival in patients with and without portal vein complication was 67% and 65%, respectively (P = 0.54). Overall graft survival in patients with and without HAT was 40% and 67%, respectively. HAT significantly affected graft survival (P = 0.04). In conclusion, our surgical technique for smaller-size recipients resulted in an acceptable rate of vascular complications. Overcoming early posttransplantation complications will further improve outcomes in infantile LDLT.

LIVING-DONOR LIVER TRANSPLANTATION IN BABIES LESS THAN 3 MONTHS OLD

O95* Background: Liver transplantation in infants in the first three months of life, neonates, offers treatment to a patient population in whom life expectancy without hepatic replacement is very limited. Although living-donor liver transplantation (LDLT) has become a well-recognized therapeutic option for children with end-stage liver disease, LDLT in neonates still remains a technically difficult and medically challenging procedure. An analysis of data regarding only LDLT in the first 3 months of life has not performed previously, while several reports about liver transplantation using not only living-donor but also cadaveric graft exist. Therefore, the aim of this retrospective study was to analyze the results of our experience with LDLT in children younger than 3 months of age and to explore strategy to improve survival in the recipients. Patients and Methods: Between June 1990 and December 2003, 600 children (<18 years old) underwent LDLT at our program. Of these, a total of 6 children (3 boys and 3 girls) before the age of 90 days at the time of transplant constitute the study population. Our previous reports have described medical management and surgical techniques. Left lateral segment graft (segments 2 and 3) in 3 cases, reduced-size grafts in 2 cases, and monosegment graft in 1 case were indicated. The arterial anastomosis was made in an end-to-end fashion between one of the hepatic arteries of the recipients and the donor hepatic artery under magnification by surgical microscope. Portal vein was reconstructed in end-to-end manner directly or via venous graft taken from the donor (inferior mesenteric vein). Donor hepatic vein was anastomosed to the stump of the left and the middle hepatic vein. Bile duct was anastomosed to the Roux-en Y loop in an end-to-end fashion. Posttransplant immunosuppression was based on oral FK506 combined with low-dose steroid. Results: The mean age and body weight of the 6 patients was 30 days (range, 27 to 74) and 4.1 kg (range, 3.5 to 4.8), respectively. The age distribution at the time of transplantation included the following: <1 month, 50%; 1–2 months, 33%; and 2–3 months, 17%. Four patients were intensive care unit bound at the time of transplant and 2 patients were hospitalized awaiting transplantation. Liver disease etiology included fluminant hepatic failure (5 cases) and tyrosinemia (1 case). Liver grafts were ABO-identical in 5 patients and ABO-incompatible in the rest. The maximum of the ratio of liver graft weight which was measured at the operation to the recipient body weight (GRWR) was 7.7. Incidence of acute cellular rejection occurred in 2 of 6 patients. Cytomegalovirus or Epstein-Barr virus infection was observed in 4 and 1 cases, respectively. Two patients have been completely withdrawn from immunosuppression for more than three years without any hepatic dysfunction. The patient survival of the neonates was 50%, with follow-up of 1 to 100 months. Three patients died after LDLT. These three deaths were due to sepsis in two cases and vascular occulusion in the other one. Maintenance immunosuppression was FK506-based. Acute rejection episodes occurred in two patients and was managed with intravenous steroid pulse and optimization of FK506. One patient had post-transplant lymphoproliferative disease. Currently, 3 of 6 recipients are alive with good graft function. Conclusions: This is the first report on LDLT in babies younger than 3 months old. From our experience, LDLT offers a promising option for the treatment of severe liver disease in neonates. These neonates should be referred promptly for liver transplantation as reasonable survival can be expected.

PORTAL VEIN OBSTRUCTION IN THE LONG-TERM COURSE AFTER PEDIATRIC LIVING DONOR LIVER TRANSPLANTATION.

O157 Aims: Portal vein stenosis or occlusion is the one of the major surgical problem in pediatric living donor liver transplantation (LDLT) with the left lobe grafts, which possibly lead to graft loss. The frequency, the time after operation, the outcome of portal vein stenosis or occlusion in the long-term course after pediatric LDLT is not clear in a large series. Methods: Between June 1990 and Septmber 2003, 527 pediatric patients received primary LDLT either with the left lobe graft, left lateral segment graft or monosegment graft. Their age ranged from 27 days to 17y9m (median; 1y10m) and their body weight at the operation ranged from 3.1 Kg to 62.4 Kg (median; 10.1 Kg). Original disease were biliary cirrhosis (n=416), metabolic diseases (n=39), fulminant liver failure (n=30), liver cirrhosis (n=17), tumors (n=15), and others (n=10). Portal vein anastomosis was performed with or without vein graft according to the size of the recipient portal vein and size mismatch between recipient and graft portal vein. Blood flow of the portal vein was checked with the doppler ultrasonography every day for the first one week and every other day for the first one month. After the patient was discharged, portal blood flow was checked in the outpatient clinic when indicated. Results: Forty-one patients (7%) showed portal vein stenosis (n=29) or occlusion (n=12). Their age ranged from 4m to 17y3m (median; 1y). and their body weight at the operation ranged from 3.8Kg to 44.8Kg (median; 8.5Kg). The portal vein stenosis or occlusion was detected in the first six months in 7 patients (17%), in the next six months in 12 patients (29%), in the second year in 7 patients (17%), between 2y and 5y in 12 patients and therafter in 2 patients. In 29 patients with portal vein stenosis, percutaneous transhepatic balloon dilatation of the portal vein was successful. Two patients received portal vein re-anastomosis at 55m and 51m after LDLT. Two patients received re-LDLT at 92m and 62m due to graft failure caused by portal vein occulusion. One patient died after re-LDLT due to infection and others are all alive between 10m and 12y3m. Decrease in the portal vein flow by the doppler ultrasonography and decrease in the platelet count were the indicative signs in the patients with portal vein stenosis or occlusion. Conclusions: Portal vein stenosis or occulusion occurred in 7% of the pediatric patients in LDLT using left lobe graft. Portal vein stenosis and occulusion can be detected with the use of Doppler ultrasonogrphy and platelet count was an indicative marker. Early detection of portal vein stenosis can lead successful balloon dilatation and can avoid graft loss.

Living-donor liver transplantation with monosegments

Living-donor liver transplantation is now an established technique to treat children with end-stage liver disease. Implantation of left-lateral segment grafts can be a problem in small infants because of a large-for-size graft. We report 10 cases of transplantation using monosegment grafts from living donors. Of 506 children transplanted between June 1990 and June 2002, 10 patients (median age 196 days, median weight 5.9 kg) received monosegment living-donor liver transplants. The indication for using this technique was infants with an estimated graft-to-recipient weight ratio of over 4.0%. Graft and patient survival was 80.0%. There were no differences in donor operation time and blood loss between monosegmentectomy and left-lateral segmentectomy (n=281). Monosegmental transplantation had a high incidence of vascular complications (20.0%). Monosegmental living- donor liver transplantation is a feasible option with satisfactory graft survival in small babies with liver failure.

Monosegmental living donor liver transplantation

BackgroundLiving donor liver transplant (LDLT) program has been started from 1990 in Japan, and is still major form of liver transplantation because of the scarcity of cadaveric donor organs. In small infants, implantation of left lateral segment grafts can be a problem because of a large-for-size graft. Until November 2002, we performed 867 transplants for 828 patients (561 children and 306 adults), and 14 cases received monosegment grafts from living donors. MethodFifteen patients, median age 211 days, median weights 5.95 kg, received monosegmental LDLT. The indication for using this technique was infants with an estimated graft-to-recipient weight ratio of over 4.0%. ResultsGraft and patient survival is 85.7%. There were no differences in donor operation time and blood loss between monosegmentectomy and left lateral segmentectomy. Segment III grafts were indicated in 13 cases. Two vascular complications were observed (one hepatic artery thrombosis and one portal vein thrombosis). ConclusionMonosegental living donor liver transplantation is a feasible option with satisfactory graft survival in small babies with liver failure.