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

Comprehensive evaluation of the ramification patterns of hepatic vascular anatomy based on three-dimensional visualization technology

The liver segmentation method proposed by Couinaud is widely accepted by surgeons because of its convenience and practicality. However, this conventional eight-segment classification does not reflect realistic details of the liver and thus requires further adjustments to promote improvements in surgical strategies. This study aimed to explore the ramification patterns of the hepatic vasculature comprehensively. A total of 197 eligible patients meeting the study criteria were enrolled for three-dimensional reconstruction analysis. In the left hemiliver, the portal vein bifurcated into P2 and umbilical portion (UP) in 172 (98.3%) patients. The P4b of 103 patients (103/172, 59.9%) whose P4b branched from the right horn of the left portal vein (LPV) diverged from the main trunk of the UP. In the right paramedian sector (RPMS), the entire portal trunk directly bifurcates into P8vent and P8dor. Simple branching of P5 off the trunk of the RPMS was observed in 78 patients (78/130, 60%). The anterior fissure vein (AFV) was identified in 86 (86/148, 58.1%) patients. V8d entered the right hepatic vein (RHV) in all the patients. In 75.3% (113/150) of all the patients, V5d joined the RHV. In the right lateral sector (RLS), more than half (71/133, 53.4%) of the patients had an arch-like type. We summarize different patterns of liver vascular branches, providing a valuable reference for clinical surgery and liver transplantation. Cranio-caudal segmentation is more common than ventral-dorsal segmentation. The AFV can be regarded as a reliable anatomical landmark for subsegmentation in segment 8. In addition, the absence of AFV was associated with the P8 pattern.

Chinese clinical practice guidelines for pediatric split liver transplantation

Liver transplantation is an effective treatment for end-stage liver disease in children, and its clinical efficacy has been validated. Split liver transplantation (SLT) can effectively expand the donor liver pool for children. SLT for children has unique clinical characteristics and principles. Establishing technical operation specifications for pediatric SLT plays a significant role in improving clinical efficacy. In this paper, clinical practice guidelines on pediatric SLT were established in the aspect of donor and donor liver evaluation, donor-recipient matching, and ductal segmentation and reconstruction of donor liver, aiming to standardize the technical process, optimize surgical operational details, minimize the risk of complications of SLT for children, further promoting the rapid development of pediatric SLT in China.

Effects of Adding Congested Segment IV to the Left Lateral Graft on Short-term Outcomes in Pediatric Living-donor Liver-transplant Recipients

Background

In some pediatric patients undergoing living-donor liver transplantation, segment IV without the middle hepatic vein can be added to a left lateral segment graft to obtain larger graft volume. Because no clear consensus on this technique exists, this study investigated the effects of congested areas on postoperative outcomes in pediatric patients with biliary atresia undergoing living-donor liver transplantation.

Methods

We retrospectively reviewed data of recipients with biliary atresia aged ≤15 y who had undergone living-donor liver transplantation at Kyoto University Hospital between 2006 and 2021 and with graft-to-recipient weight ratios (GRWR) of ≤2%. Based on the percentage of congested area in the graft, patients were classified into the noncongestion (n = 40; ≤10%) and congestion (n = 13; >10%) groups. To compare the differences between groups with similar nooncongestive GRWRs and investigate the effect of adding congested areas, patients in the noncongestion group with GRWRs of ≤1.5% were categorized into the small noncongestion group (n = 24).

Results

GRWRs and backgrounds were similar between the noncongestion and congestion groups; however, patients in the congestion group demonstrated significantly longer prothrombin times, higher ascites volumes, and longer hospitalization. Further, compared with the small noncongestion group, the congestion group had significantly greater GRWR and similar noncongestive GRWR; however, the congestion group had significantly longer prothrombin time recovery (P = 0.020, postoperative d 14), higher volume of ascites (P < 0.05, consistently), and longer hospitalization (P = 0.045), requiring significantly higher albumin and gamma-globulin transfusion volumes than the small noncongestion group (P = 0.027 and P = 0.0083, respectively). Reoperation for wound dehiscence was significantly more frequent in the congestion group (P = 0.048).

Conclusions

In pediatric liver-transplant recipients, adding a congested segment IV to the left lateral segment to obtain larger graft volume may negatively impact short-term postoperative outcomes.

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).

Hepatic venous reconstruction of the left lateral segment with emphasis on anomalous hepatic vein in pediatric liver transplantation

Left lateral segment grafts have become a suitable option in pediatric liver transplantation (PLT). The correlation between hepatic vein (HV) reconstruction and outcome is relevant when assessing the safe use of these grafts. We retrospectively reviewed the medical records prospectively collected from a pediatric living donor liver transplantation database and conducted a comparative analysis of the different left lateral segment graft types according to HV reconstruction. Donor, recipient, and intraoperative variables were analyzed. Post-transplant outcomes included vascular complications such as hepatic vein outflow obstruction, early (≤30 d) and late (>30 d) PVT, hepatic artery thrombosis, and graft survival. From February 2017 to August 2021, 303 PLTs were performed. According to venous anatomy, the distribution of the left lateral segment was as follows: single HV (type I) in 174 (57.4%), close HVs, simple venoplasty for reconstruction (type II) in 97 (32.01%), anomalous hepatic vein (AHV) with a distance between the HVs orifices that allowed simple venoplasty (type IIIA) in 25 (8.26%) and AHV with a distance between the HVs orifices requiring homologous venous graft interposition (type IIIB) in 07 (2.31%) grafts. Type IIIB grafts came from male donors ( p =0.04) and had a higher mean donor height ( p =0.008), a higher mean graft weight, and a higher graft-to-recipient weight ratio, both p =0.002. The median follow-up time was 41.4 months. The overall cumulative graft survival was 96.3%, and comparative graft survival showed no difference (log-rank p =0.61). No hepatic vein outflow obstructions were observed in this cohort study. There was no statistically significant difference in the post-transplant outcomes between the graft types. The venous reconstruction of the AHV with homologous venous graft interposition had similar outcomes in the short and long term.

Advanced preoperative three-dimensional planning decreases the surgical complications of using large-for-size grafts in pediatric living donor liver transplantation

BACKGROUND

Using "large-for-size" liver graft, graft-to-recipient weight ratio (GRWR) ≥4%, has been debated in pediatric liver transplantation due to possible graft compartment after abdomen closure. Meticulous preoperative evaluation with three-dimensional (3D) techniques may prevent these problems. This study compared the safety of large-for-size grafts in pediatric living donor liver transplantation (PLDLT) during the eras with or without 3D planning.

METHODS

We defined the 3D era was after November 2017 due to our first implication of 3D printing for surgical planning and subsequently developing a 3D simulation implanting model. From November 2004 to July 2021, we enrolled 30 PLDLT patients with body weight (BW) < 10 kg and categorized them into conventional group: GRWR ≥4% before the 3D era (n = 9), 3D group: GRWR ≥4% in the 3D era (n = 8), and control group: GRWR <4% (n = 13). We followed and compared their clinical outcomes.

RESULTS

The 3D group had the lowest BW and the highest graft volume reduction rate, with all receiving modified left lateral segments (LLS), such as reduced LLS (n = 2), hyperreduced LLS (n = 5), and segment 2 monosegment (n = 1). Overall postoperative complications were similar in conventional and control groups but significantly lower in the 3D group (OR 0.06, 95% CI 0.006-0.70, p = 0.025). However, all groups had similar graft and patient survival at 1, 2, and 4 years.

CONCLUSION

Advanced preoperative 3D planning can decrease post-transplant complications and increase the safety of large-for-size grafts in PLDLT.

LEVEL OF EVIDENCE

Type of study: Retrospective comparative study; Evidence level: Level III.

Left lateral segment liver volume is not correlated with anthropometric measures

BACKGROUND

Liver transplantation is definitive therapy for end stage liver disease in pediatric patients. Living donor liver transplantation (LDLT) with the left lateral segment (LLS) is often a feasible option. However, the size of LLS is an important factor in donor suitability - particularly when the recipient weighs less than 10 kg. In the present study, we sought to define a formula for estimating left lateral segment volume (LLSV) in potential LLS donors.

METHODS

We obtained demographic and anthropometric measurements on 50 patients with Computed Tomography (CT) scans to determine whole liver volume (WLV), right liver volume (RLV), and LLSV. We performed univariable and multivariable linear regression with backwards stepwise variable selection (p < 0.10) to determine final models.

RESULTS

Our study found that previously reported anthropometric and demographics variables correlated with volume were significantly associated with WLV and RLV. On univariable analysis, no demographic or anthropometric measures were correlated with LLSV. On multivariable analysis, LLSV was poorly predicted by the final model (R2 = 0.10, Coefficient of Variation [CV] = 42.2) relative to WLV (R2 = 0.33, CV = 18.8) and RLV (R2 = 0.41, CV = 15.8).

CONCLUSION

Potential LLS living donors should not be excluded based on anthropometric data: all potential donors should be evaluated regardless of their size.

Outcomes After Living Donor Liver Transplantation in Pediatric Patients with Inherited Metabolic Diseases

BACKGROUND There is no consensus about the long-term prognosis of pediatric patients with a variety of rare liver diseases but with inherited metabolic diseases (IMDs). We retrospectively reviewed the developmental outcomes of patients with IMDs undergoing living donor liver transplantation (LDLT). MATERIAL AND METHODS Between May 2001 and December 2020, of 314 pediatric patients who underwent LDLT, 44 (14%) had IMDs. The median age at LDLT was 3.0 years old (range 0-15.0 years). Associations between the post-transplant complications and graft survival rate in patients with IMDs and biliary atresia (BA) were calculated. We evaluated the safety of LDLT from heterozygous carrier donors, the prognosis of patients with IMDs who have metabolic defects expressed in other organs, and developmental outcomes of patients with IMDs. RESULTS The 10-year graft survival rates in patients with IMDs and BA were 87% and 94%, respectively (P=0.041), and the causes of graft failure included pneumocystis pneumonia, acute lung failure, hemophagocytic syndrome, hepatic vein thrombosis, portal vein thrombosis, and sepsis. The rate of post-transplant cytomegalovirus viremia in patients with IMDs was higher than that of patients with BA (P=0.039). Of 39 patients with IMDs, 15 patients (38%) had severe motor and intellectual disabilities in 4 patients, intellectual developmental disorders including epilepsy in 2, and attention-deficit hyperactivity disorder in 2. Of 28 patients with IMDs, 13 (46%) needed special education. CONCLUSIONS The long-term outcomes of LDLT in patients with IMDs are good. However, further long-term social and educational follow-up regarding intellectual developmental disorders is needed.

Living donor liver transplantation for small infants aged less than 6 months: The experience of a single institute

PURPOSE

Liver transplantation (LT) for small infants < 6 months old is rare but becoming common as perioperative care improves. In Taiwan, living donor LT (LDLT) has expanded indications but is rarely performed for this age group because of unfavorable outcomes in the literature. We evaluated LDLT outcomes of patients <6 months old.

METHODS

We identified infants < 6 months old undergoing LDLT between 2004 and 2019 at our hospital. Variables related to recipients, donors, surgeries, and outcomes were analyzed.

RESULTS

Nine patients were identified. Indications for LT were biliary atresia (n = 2), Alagille syndrome (n = 1), protein C deficiency (n = 1), and acute liver failure (n = 5), including two patients with neonatal hemochromatosis, one with herpes simplex hepatitis, one with giant cell hepatitis with autoimmune hemolytic anemia, and one with hemophagocytic lymphohistiocytosis. Median age and weight at LT were 129 days and 4.8 kg, respectively. Graft types included left lateral segment (LLS, n = 4), hyper-reduced LLS (n = 4), and monosegment (n = 1). The median graft-to-recipient weight ratio was 4%. The median follow-up period was 14 months (range, 8 days to 127 months) with two mortalities, and two patients were totally weaned off immunosuppressants. Adjuvant therapies were required for patients with giant cell hepatitis and hemophagocytosis. Preoperative reconstructive imaging for estimating graft thickness facilitated surgical planning.

CONCLUSION

Although LDLT is difficult to perform for small infants, outcomes are favorable and mainly dependent on underlying causes in addition to technical innovations.

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.

Long-Term Outcomes of Abdominal Wall Reconstruction with Expanded Polytetrafluoroethylene Mesh in Pediatric Liver Transplantation

Background: Large-for-size syndrome caused by organ size mismatch increases the risk of abdominal compartment syndrome. Massive transfusion and portal vein clamping during liver transplantation may cause abdominal compartment syndrome (ACS) related to mesenteric congestion. In general pediatric surgery—such as correcting gastroschisis—abdominal wall reconstruction for the reparation of defects using expanded polytetrafluoroethylene is an established method. The purpose of this study is to describe the ePTFE-Gore-Tex closure method in patients with or at a high risk of ACS among pediatric liver transplant patients and to investigate the long-term prognosis and outcomes. Methods: From March 1988 to March 2018, 253 pediatric liver transplantation were performed in Seoul National University Hospital. We retrospectively reviewed the cases that underwent abdominal wall reconstruction with ePTFE during liver transplantation. Results: A total of 15 cases underwent abdominal closure with ePTFE-GoreTex graft. We usually used a 2 mm × 10 cm × 15 cm sized Gore-Tex graft for extending the abdominal cavity. The median follow up was 59.5 (17–128.7) months and there were no cases of ACS after transplantation. There were no infectious complications related to ePTFE implantation. The patient and graft survival rate during the study period was 93.3% (14/15). Conclusions: Abdominal wall reconstruction using ePTFE is feasible and could be an alternative option for patients with a high risk of ACS.

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.

Pediatric liver transplantation with hyperreduced left lateral segment graft

Backgrounds/Aims

To prevent large-for-size graft-related complications in small infant patients, the size of a left lateral segment (LLS) graft can be reduced to be a hyperreduced LLS (HRLLS) graft.

Methods

This study was intended to describe the detailed techniques for harvesting and implanting HRLLS grafts developed in a high-volume liver transplantation (LT) center.

Results

The mean recipient age was 4.0±1.7 months (range: 3-6) and body weight was 5.3±1.4 kg (range: 4.1-6.9). Primary diagnoses of the recipients were progressive familial intrahepatic cholestasis in 2 and biliary atresia in 1. The types of LT were living donor LT in 1 and split deceased donor LT in 2. Non-anatomical size reduction was performed to the transected LLS grafts. The mean weight of the HRLLS grafts was 191.7±62.1 g (range: 120-230) and graft-recipient weight ratio was 3.75±1.57% (range: 2.45-5.49). Widening venoplasty was applied to the graft left hepatic vein outflow orifice. Vein homograft interposition was used in a case with portal vein hypoplasia. Types of the abdomen wound closure were one case of primary repair, one of two-staged closure with a mesh, and one of three-staged repair with a silo and a mesh. All three patients recovered uneventfully from the LT operation and are doing well to date for more than 6 years after transplantation.

Conclusions

Making a HRLLS graft through non-anatomical resection during living donor LT and split deceased donor LT can be a useful option for treating small infant patients.

Pediatric split liver transplantation using a hyperreduced left lateral segment graft in an infant weighing 4 kg

We present a case of successful split liver transplantation (LT) using a hyperreduced left lateral segment (LLS) graft in a 106-day-old female infant patient weighing 4 kg. The patient was diagnosed with progressive familial intrahepatic cholestasis. Her general condition and liver function deteriorated progressively and she was finally allocated for a split LT under status 1. The deceased donor was a 20-year-old female weighing 63.7 kg. We performed in situ liver splitting and in situ size reduction sequentially. The weight of the hyperreduced LLS graft was 225 g, with a graft-recipient weight ratio of 5.5%. We performed recipient hepatectomy and graft implantation according to the standard procedures for pediatric living-donor LT. Since the graft was too large for primary abdomen closure, the abdominal wall was closed in three stages to make a prosthetic silo, temporary closure with a xenograft sheet, and final primary repair over 2 weeks. The patient has been doing well for more than 6 years after transplantation. In conclusion, split LT using a hyperreduced LLS graft can be a useful option for treating small infants. However, large-for-size graft-related problems, particularly in terms of graft thickness, still remain to be solved.

Outcome after pediatric liver transplantation for staged abdominal wall closure with use of biological mesh-Study with long-term follow-up

Abdominal wall closure after pediatric liver transplantation (pLT) in infants may be hampered by graft-to-recipient size discrepancy. Herein, we describe the use of a porcine dermal collagen acellular graft (PDCG) as a biological mesh (BM) for abdominal wall closure in pLT recipients. Patients <2 years of age, who underwent pLT from 2011 to 2014, were analyzed, divided into definite abdominal wall closure with and without implantation of a BM. Primary end-point was the occurrence of postoperative abdominal wall infection. Secondary end-points included 1- and 5-year patient and graft survival and the development of abdominal wall hernia. In five out of 21 pLT recipients (23.8%), direct abdominal wall closure was achieved, whereas 16 recipients (76.2%) received a BM. BM removal was necessary in one patient (6.3%) due to abdominal wall infection, whereas no abdominal wall infection occurred in the no-BM group. No significant differences between the two groups were observed for 1- and 5-year patient and graft survival. Two late abdominal wall hernias were observed in the BM group vs none in the no-BM group. Definite abdominal wall closure with a BM after pLT is feasible and safe when direct closure cannot be achieved with comparable postoperative patient and graft survival rates.

Pediatric living donor liver transplantation with large-for-size left lateral segment grafts

Usage of "large-for-size" left lateral segment (LLS) liver grafts in children with high graft to recipient weight ratio (GRWR) is controversial due to concerns about increased recipient complications. During the study period, 77 pediatric living donor liver transplantations (LDLTs) with LLS grafts were performed. We compared recipients with GRWR ≥2.5% (GR-High = 50) vs GRWR <2.5% (GR-Low = 27). Median age was higher in the GR-Low group (40 vs 8 months, P> .0001). Graft (GR-High: 98%, 98%, 98% vs GR-Low: 96%, 93%, 93%) and patient (GR-High: 98%, 98%, 98% vs GR-Low: 100%, 96%, 96%) survival at 1, 3, and 5 years was similar between groups (P = NS). Overall complications were also similar (34% vs 30%; P = .8). Hepatic artery and portal vein thrombosis following transplantation was not different (P = NS). Delayed abdominal fascia closure was more common in GR-High patients (17 vs 1; P = .002). Subgroup analysis comparing recipients with GRWR ≥4% (GR-XL = 20) to GRWR <2.5% (GRWR-Low = 27) revealed that delayed abdominal fascia closure was more common in the GR-XL group, but postoperative complications and graft and patient survival were similar. We conclude that pediatric LDLT with large-for-size LLS grafts is associated with excellent clinical outcomes. There is an increased need for delayed abdominal closure with no compromise of long-term outcomes. The use of high GRWR expands the donor pool and improves timely access to the benefits of transplantation without extra risks.

Feasibility and safety of using low-body-weight donors in pediatric liver transplantation

BACKGROUND

Donors with low-body-weight were previously reported to be related to inferior recipient outcomes in pediatric liver transplantation. However, the scarce availability of age and size-matched organs has encouraged us to re-evaluate the feasibility and safety of using low-body-weight donors.

METHODS

We retrospectively analyzed 91 deceased donor pediatric liver transplantation between January 2014 and December 2016, donor weight less than 5 kg was defined as low-body-weight donors. The recipients were divided into two groups according to donor weight. (≤5 kg and 5 kg < to ≤20 kg). Donor and recipient characteristics, perioperative data, postoperative complications as well as graft and recipient survival rate were compared RESULTS: The recipients and grafts recovery after transplantation were comparable between two groups. The recipients receiving low-body-weight donors showed higher risk of hepatic artery thrombosis and small-for-size syndrome, however, these complications can effectively be treated by our strategies. The 2-year patient survival rates were 92.9% and 95.2%, 2-year graft survival rates were 92.9% and 93.7% in Groups 1 and 2, without significant difference.

CONCLUSIONS

Our finding suggested that the utility of livers from low-body-weight donors is a potential strategy to increase donor availability in well-selected pediatric recipients.

LEVEL OF EVIDENCE

III.

Pediatric liver transplantation for neonatal-onset Niemann-Pick disease type C: Japanese multicenter experience

Niemann-Pick disease type C (NPC) is a rare autosomal recessive inherited disease characterized by lysosomal accumulation of free cholesterol in macrophages within multiple organs. Infantile-onset NPC often presents with jaundice and hepatosplenomegaly from birth, but these symptoms usually improve during early childhood, and it rarely progresses to liver failure. We report three cases from different hospitals in Japan; the patients developed neonatal-onset NPC, and liver transplantation (LT) was performed as a life-saving procedure. LT was performed at 19 days, 59 days, and 4 months of age, respectively. The last patient was diagnosed with NPC before LT, while the first two patients were diagnosed with neonatal hemochromatosis at LT. In these two patients, the diagnosis of NPC was made more than a year after LT. Even though oral administration of miglustat was started soon after the diagnosis of NPC, all patients showed neurological regression and required artificial respiratory support. All patients survived more than one year after LT; however, one patient died due to tracheal hemorrhage at 4.5 years of age, and another one patient was suspected as recurrence of NPC in liver graft. In conclusion, while LT may be a temporary life-saving measure in patients with neonatal-onset NPC leading to liver failure, the outcome is poor especially due to neurological symptoms. A preoperative diagnosis is thus critical.

Early Hepatic Artery Thrombosis After Pediatric Living Donor Liver Transplantation

AIM

Hepatic artery thrombosis is one of the major complications affecting patient and graft survival after liver transplantation. In this study, we analyzed the factors affecting the development of early hepatic artery thrombosis (eHAT) and its outcomes in pediatric liver transplantation.

METHODS

A total of 175 pediatric patients underwent living donor liver transplantation between January 2013 and November 2018. Factors affecting eHAT and its outcomes were examined.

RESULTS

Nine patients (5.1%) developed eHAT. In multivariate analysis, intraoperative hepatic artery revision and Roux-en-Y hepaticojejunostomy biliary reconstruction type were statistically significant (all, P < .05). Thrombectomy and reanastomosis was performed in 5 patients. Two of them were successful. In total, 3 retransplantations were performed and all of those patients are still alive.

CONCLUSION

The factors affecting eHAT are still a matter of debate. Intraoperative hepatic artery anastomosis revision and Roux-en-Y hepaticojejunostomy reconstruction were independent risk factors for development of eHAT. In the present study, the confidence interval of the variables is high, therefore exact determination of the risk factors may not be possible. Early detection and thrombectomy and reanastomosis may be the first treatment of choice to rescue the patient and graft. When it fails, retransplantation must be an alternative. The results of the present study state that at least once a day the vascular anastomosis must be examined by Doppler ultrasonography in the post-transplant first week. It must be repeated when liver enzymes increase. The patients under high risk for eHAT may be followed up closer.

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.

Computed tomography donor liver volumetry before liver transplantation in infants ≤10 kg: does the estimated graft diameter affect the outcome?

Aim of the study

Living donor liver transplantation (LDLT) is regularly performed in small-sized infants. Computed tomography (CT)-based donor liver volumetry is used to estimate the graft size. The aim of our study was to assess the results of CT liver volumetry and their impact on the clinical outcome after LDLT in extremely small-sized infants.

Patients and methods

In this study, we included all patients with a body weight of ≤10 kg who underwent living related liver transplantation at our centre between January 2004 and December 2014. In all cases of LDLT, a preoperative CT scan of the donor liver was performed, and the total liver and graft volumes were calculated. The graft shape was estimated by measuring the ventro-dorsal (thickness), cranio-caudal, and transversal (width) diameter of segment II/III. We assessed the impact of CT donor liver volumetry and other risk factors on the outcome, defined as patient and graft survival.

Results

In the study period, a total of 48 living related liver transplantations were performed at our centre in infants ≤10 kg [20 male (42%), 28 female (58%)]. The mean weight was 7.3 kg (range 4.4–10 kg). Among the recipients, 33 (69%) received primary abdominal closure and 15 (31%) had temporary abdominal closure. The patient and graft survival rates were 85% and 81%, respectively. In CT volumetry, the mean estimated graft volume was 255 mL (range 140–485 mL) and the actual measured mean graft weight was 307 g (range 127–463 g). The mean ventro-dorsal diameter of segment II/III was 6.9 cm (range 4.3–11.2 cm), the mean cranio-caudal diameter was 9 cm (range 5–14 cm), and the mean width was 10.5 cm (range 6–14.7 cm). The mean graft-body weight ratio (GBWR) was 4.38% (range 1.41–8.04%). A high graft weight, a GBWR >4%, and a large ventro-dorsal diameter of segment II/III were risk factors for poorer patient survival.

Conclusion

Preoperative assessment of the graft size is a crucial investigation before LDLT. For extremely small-sized recipients, not only the graft weight but also the graft shape seems to affect the outcome.

Rescue case of low birth weight infant with acute hepatic failure

We report a case involving a rescued low birth weight infant (LBWI) with acute liver failure. Case: The patient was 1594 g and 32^3/7 gestational wk at birth. At the age of 11 d, she developed acute liver failure due to gestational alloimmune liver disease. Exchange transfusion and high-dose gamma globulin therapy were initiated, and body weight increased with enteral nutrition. Exchange transfusion was performed a total of 33 times prior to living donor liver transplantation (LDLT). Her liver dysfunction could not be treated by medications alone. At 55 d old and a body weight of 2946 g, she underwent LDLT using an S2 monosegment graft from her mother. Three years have passed with no reports of intellectual disability or liver dysfunction. LBWIs with acute liver failure may be rescued by LDLT after body weight has increased to over 2500 g.

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.