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

Hyperreduced left lateral living donor liver transplant in a 4.5 kg child-A first in Africa

BACKGROUND

Supply-demand mismatch in solid organ transplantation is particularly pronounced in small children. For liver transplantation, advanced surgical techniques for reducing deceased and living donor grafts allow access to life-saving transplantation. Living donor left lateral segment liver grafts have been successfully transplanted in small children in our center since 2013, the only program providing this service in Sub-Saharan Africa. This type of partial graft remains too large for children below 6 kg body weight and generally requires reduction.

METHODS

A left lateral segment graft was reduced in situ from a directed, altruistic living donor to yield a hyperreduced left lateral segment graft.

RESULTS

The donor was discharged after 6 days without complications. The recipient suffered no technical surgical complications except for an infected cut-surface biloma and biliary anastomotic stricture and remains well 9 months post-transplant.

CONCLUSIONS

We report the first known case in Africa of a hyperreduced left lateral segment, ABO incompatible, living donor liver transplant in a 4,5 kg child with pediatric acute liver failure (PALF).

Outcome of split-liver transplantation from pediatric donors weighing 25 kg or less

The lower limit of body weight for "splitable" liver grafts remains unknown. To examine the outcome of split-liver transplantation (SLT) from pediatric donors ≤25 kg relative to conventional graft-type liver transplantation from deceased donors under corresponding conditions, a total of 158 patients who received primary liver transplantation, including 22 SLTs from donors ≤25 kg, 46 SLTs from donors >25 kg, 76 whole-liver transplantations, and 14 reduced-liver transplantations in donors ≤25 kg between January 2018 and December 2019, were included in the study. There was no significant difference in the complications, patient survival, and graft survival between each of the latter three groups and the SLT ≤25 kg group. Pediatric End-Stage Liver Disease (PELD) score was the independent predictor of graft loss (death or retransplantation). Graft weight was the independent predictor of hepatic artery thrombosis. SLT using well-selected pediatric donors ≤25 kg is an effective strategy to increase organ availability, especially for low-body-weight recipients, compared with conventional graft type from deceased donors under the condition of corresponding donor weight without increasing morbidity and mortality.

Predictors of portal vein complications after pediatric liver transplantation: A German center experience

BACKGROUND

Portal vein complications (PVCs) after pediatric liver transplantation (LT) are sometimes asymptomatic, especially in the early phase, and can threaten both the graft and patient's survival. Therefore, the purpose of this study is to analyze the risk factors for portal vein thrombosis (PVT) and portal vein stenosis (PVS) after pediatric LT.

METHODS

All pediatric patients (n = 115) who underwent primary LT at Regensburg University Hospital between January 2010 and April 2017 were included in this study. The pre-, intra-, and postoperative parameters of all patients were retrospectively reviewed and risk factors for both PVT and PVS were analyzed.

RESULTS

Of the 115 patients, living donor LT was performed on 57 (49.5%) patients, and biliary atresia was the primary diagnosis in 65 patients (56%). After pediatric LT, 9% of patients developed PVT, and 16.5% developed PVS. Patient weight ≤7 kg [odds ratio (OR) 9.35, 95% confidence interval (CI) 1.03-84.9, p = .04] and GRWR >3% (OR 15.4, 95% CI 1.98-129.5, p = .01) were the independent risk factors for the development of PVT and PVS, respectively upon multivariate analysis. The overall patient survival rates at 1, 3, and 5 years were 91%, 90%, and 89%, respectively, and there was no difference in patient survival among those with and without PVCs.

CONCLUSIONS

Pediatric patients with body weight <7 kg and/or receiving a graft with GRWR >3% may develop PVCs and so require certain surgical modifications, close follow-up, and prophylactic anticoagulant therapy following transplant.

A Novel Strategy for Preventing Posttransplant Large-For-Size Syndrome in Adult Liver Transplant Recipients: A Pilot Study

There are two causes of graft compression in the large-for-size syndrome (LFSS). One is a shortage of intra-abdominal space for the liver graft, and the other is the size discrepancy between the anteroposterior dimensions of the liver graft and the lower right hemithorax of the recipient. The former could be treated using delayed fascial closure or mesh closure, but the latter may only be treated by reduction of the right liver graft to increase space. Given that split liver transplantation has strict requirements regarding donor and recipient selections, reduced-size liver transplantation, in most cases, may be the only solution. However, surgical strategies for the reduction of the right liver graft for adult liver transplantations are relatively unfamiliar. Herein, we introduce a novel strategy of HuaXi-ex vivo right posterior sectionectomy while preserving the right hepatic vein in the graft to prevent LFSS and propose its initial indications.

3D-reconstruction and heterotopic implantation of reduced size monosegment or left lateral segment grafts in small infants: A new technique in pediatric living donor liver transplantation to overcome large-for-size syndrome

BACKGROUND

Monosegmental grafts and reduced left lateral segment grafts have been introduced to overcome the problems of large-for-size grafts in pediatric living donor liver transplantation. Here, we introduce a new method of reduced size monosegment or left lateral segment grafts transplanted in the right diaphragmatic fossa heterotopically in small infants.

METHODS

There were 4 infants who underwent living donor liver transplantation with heterotopically implanted reduced monosegmental or left lateral segment grafts at our center. The demographic, operative, postoperative, and follow-up data of these infants were collected from our prospectively designed database and reviewed. Technical details of the donor and recipient operation are shared and a supplemental provided.

RESULTS

The mean recipient age was 7.5 ± 0.9 months (range: 5-10 months), and body weight was 5.9 ± 0.7 kg (range: 4.6-7.8). Primary diagnoses of the recipients were biliary atresia (n:3) and progressive familial intrahepatic cholestasis (n:1). Mean graft-recipient weight ratio was 3.3 ± 0.2. Reduced monosegment III grafts were used in 2 cases, and reduced left lateral segment grafts were used in the other 2 patients. Bile duct reconstruction was done by Roux-en-Y hepaticojejunostomy in 3 patients and duct-to-duct anastomosis in the remaining patient. All patients recovered from the liver transplantation operation and are doing well at a mean follow-up of 8 months.

CONCLUSION

Living donor liver transplantation with heterotopically implanted reduced monosegmental or left lateral segment seems feasible for the treatment of neonates and extremely small infants. Further accumulation of cases and long-term follow-up are necessary to collect data for the establishment of this treatment modality.

Liver Transplantation in Children: An Overview of Organ Allocation and Surgical Management

Liver transplantation is the standard treatment for children with end-stage liver disease, primary hepatic neoplasms, or liver-localized metabolic defects. Perioperative mortality is almost absent, and long-term survival exceeds 90%. Organ shortage is managed thanks to advances in organ retrieval techniques; living donation and partial liver transplantation almost eliminated waiting list mortality, thus leading to expanding indications for transplantation. The success of pediatric liver transplantation depends on the prompt and early referral of patients to transplant Centers and on the close and integrated multidisciplinary collaboration between pediatricians, hepatologists, surgeons, intensivists, oncologists, pathologists, coordinating nurses, psychologists, and social workers.

Antithrombotic management and thrombosis rates in children post-liver transplantation: A case series and literature review

Thrombosis is a major postoperative complication in pediatric liver transplantation. There is marked heterogeneity in prophylactic antithrombotic therapies used, without established guidelines. This review summarizes current worldwide incidence of thrombotic events and compares antithrombotic therapies in children post-liver transplant, with comparison to our institution's experience. Of the twenty-three articles with sufficient detail to compare antithrombotic regimens, the overall incidence of thrombosis ranged from 2.4% to 17.3%. Incidence of HAT ranged from 0% to 28.1%, of HVT from 0% to 4.7%, of PVT from 1.5% to 11.2%, and of IVC thrombosis from 0% to 2.8%. Re-transplantation due to thrombosis ranged from 0% to 4.8%. Prophylactic antithrombotic therapies varied between studies, and bleeding complications were infrequently reported. Since 2010, 96 children underwent 100 liver transplants at our institution with thrombosis incidence comparable to international literature (HAT 6%, PVT 5%, IVC 1%, and HVT 0%). Re-transplantation due to thrombosis occurred in 2% and major bleeding occurred in 10%. The prophylactic antithrombotic therapies used post-liver transplantation in children remain varied. Low rates of thrombosis have been reported with antiplatelet use both with and without anticoagulation. Standard definitions and consistent reporting of bleeding complications are required, in addition to thrombosis rates, so that true risk-benefit assessment of reported regimes can be understood.

Variability of surgical prophylaxis in penicillin-allergic children

We retrospectively evaluated the effect of penicillin adverse drug reaction (ADR) labeling on surgical antibiotic prophylaxis. Cefazolin was administered in 86% of penicillin ADR-negative (−) and 28% penicillin ADR-positive (+) cases. Broad-spectrum antibiotic use was more common in ADR(+) cases and was more commonly associated with perioperative adverse drug events.

Extreme large-for-size syndrome after adult liver transplantation: A model for predicting a potentially lethal complication

There is currently no tool available to predict extreme large-for-size (LFS) syndrome, a potentially disastrous complication after adult liver transplantation (LT). We aimed to identify the risk factors for extreme LFS and to build a simple predictive model. A cohort of consecutive patients who underwent LT with full grafts in a single institution was studied. The extreme LFS was defined by the impossibility to achieve direct fascial closure, even after delayed management, associated with early allograft dysfunction or nonfunction. Computed tomography scan-based measurements of the recipient were done at the lower extremity of the xiphoid. After 424 LTs for 394 patients, extreme LFS occurred in 10 (2.4%) cases. The 90-day mortality after extreme LFS was 40.0% versus 6.5% in other patients (P = 0.003). In the extreme LFS group, the male donor-female recipient combination was more often observed (80.0% versus 17.4%; P < 0.001). The graft weight (GW)/right anteroposterior (RAP) distance ratio was predictive of extreme LFS with the highest area under the curve (area under the curve, 0.95). The optimal cutoff was 100 (sensitivity, 100%; specificity, 88%). The other ratios based on height, weight, body mass index, body surface area, and standard liver volume exhibited lower predictive performance. The final multivariate model included the male donor-female recipient combination and the GW/RAP. When the GW to RAP ratio increases from 80, 100, to 120, the probability of extreme LFS was 2.6%, 9.6%, and 29.1% in the male donor-female recipient combination, and <1%, 1.2%, and 4.5% in other combinations. In conclusion, the GW/RAP ratio predicts extreme LFS and may be helpful to avoid futile refusal for morphological reasons or to anticipate situation at risk, especially in female recipients. Liver Transplantation 23 1294-1304 2017 AASLD.

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.

Segment 4 architecture and proposed parenchyma-wise technique for Ex vivo graft procurement and implantation

A parenchyma-wise technique for the ex vivo procurement of segment 4 (S4) grafts, based on the detailed architecture of the segment, is proposed. Eighteen normal, fresh livers from adult cadavers were injected differentially with colored latex; dissection casts were prepared; and the intricate architecture of S4 was studied. The portal vein elements of the sheath forming most of the inferior part of S4 (S4b) and the superficial major fraction of its superior part (S4a) arose constantly from the medial aspect of the umbilical part of the left portal vein branch. The arterial elements arose constantly from a branch, whose diameter ranged from 2.00 to 3.35 mm (mean = 2.61 ± 0.54 mm) and whose length ranged from 15.15 to 45.65 mm (mean = 27.98 ± 12.13 mm). The biliary elements coalesced as a single duct at the corner, which was formed from the umbilical and transverse parts of the left portal vein branch; the duct's diameter ranged from 2.90 to 6.85 mm (mean = 3.90 ± 1.34 mm). Theoretically, this parenchymal mass-S4b and the superficial fraction of S4a-could be procured for implantation in an infant, and the rest of the liver could be split for an adult and a child. The portal vein branches of the graft would be procured with a patch from the medial aspect of the donor's umbilical portion of the left portal vein branch. This umbilical portion would be reconstructed with a patch from the donor's round ligament. The recipient's portal vein would be reconstructed through the fashioning of a conduit anastomosed with the graft's venous patch.

A formula to calculate the standard liver volume in children and its application in pediatric liver transplantation

Due to a lack of available size-matched liver grafts from children, most pediatric recipients are transplanted with technical variant grafts from adult donors. Size requirements for these grafts are not well defined, and consequences of mismatched graft sizes in pediatric liver transplantation are not known. Existing formulas for calculation of a standard liver volume are mostly derived from adults disregarding the age-related percentual liver weight changes in children. In this study, we aimed to establish a formula for general use in children to calculate the standard liver volume. In a second step, the formula was applied in pediatric patients undergoing liver transplantation at our institution between 2000 and 2010 (n = 377). Analysis of a large number (n = 388) of autopsy data from children by regression analysis revealed a best fit for two formulas: "Formula 1," children 0 to ≤1 year (n = 246): standard liver volume [ml] = -143.062973 +4.274603051 * body length [cm] + 14.78817631 * body weight [kg]; "Formula 2," children >1 to <16 years (n = 142): standard liver volume [ml] = -20.2472281 + 3.339056437 * body length [cm] + 13.11312561 * body weight [kg]. In comparison with children receiving size-matched organs, we found an elevated risk of liver graft failure in children transplanted with a small-for-size graft, whereas large-for-size organs seem to have no negative impact.

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.

Successful Treatment of Biliary Atresia in Very Small Infants through Living Related Liver Transplantation

Improving outcomes in very small children is a major goal of pediatric liver transplantation. This report describes our experience of living related liver transplantation in an infant weighing 3.98 kg. The recipient, a 80-day-old male infant with congenital biliary atresia, was treated with living donor liver transplantation and then followed up for 6 months. The left lateral segment (segment II, III) with reduced size from the donor, his 26-year-old mother, was used as the graft. The graft weighed 200 g. The graft weight to recipient body weight ratio was 5.025%. The donor regained her liver function within 3 days and was discharged on day 8. The patient showed good results. Liver function returned to normal 9 days after the operation with bilirubin level almost decreased to normal. Cyclosporin, mycophenolate mofetil and prednisone were used for postoperative immunosuppression. No bleeding, thrombosis, infection or bile leakage occurred. The patient had slight fever because of a little collection in the abdomen and recovered after paracentesis and drainage. He was discharged on day 16. The donor and recipient are in satisfactory condition at present. Improvement of technique in hepatic surgery, microsurgical technique in vascular surgery and postoperative intensive care are the keys to ensure the success of the procedure.

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.