Status of liver transplantation in infants < 5 kg

Pediatric deceased donor liver transplantation with in situ size reduction for recipient-graft size matching

We present a case of pediatric deceased donor liver transplantation using a reduced whole liver graft in a 25-month-old boy weighing 12.7 kg. After he had undergone Kasai portoenterostomy for biliary atresia, his general condition deteriorated progressively. He was enrolled on the waiting list for liver transplantation with Pediatric End-stage Liver Disease score of 15. The donor was a 51-monthold boy with body weight of 20 kg. The donor-to-recipient body weight ratio was 158%. The liver graft appeared to be larger than the recipient's abdominal cavity. Thus, we planned to do in situ size reduction. Recipient surgery was performed following standard procedures. We performed graft outflow vein reconstruction using a modified piggyback technique like the double inferior vena cava method. Since the portal vein was hypoplastic, a side-to-side anastomosis technique was used. We also performed intraoperative portogram to embolize venous collaterals. After completing the graft implantation, we found that the liver graft was too large to be accommodated within the abdomen. After in situ resection of the left lateral section parenchyma, we successfully performed primary closure of the abdominal wound. This patient experienced episodes of acute rejection. He has been doing well for four years after the transplantation.

Whole liver deceased donor liver transplantation for pediatric recipients: single-center experience for 20 years

Background

We investigated the incidence and outcomes of pediatric deceased donor liver transplantation (DDLT) using whole liver grafts in a high-volume liver transplantation (LT) center.

Methods

The study was a retrospective single-center analysis of whole LT in pediatric recipients. The study period was set as 20 years between January 2000 and December 2019. We defined pediatric recipients and donors to be aged ≤18 years.

Results

During the study period, there were 98 cases of pediatric DDLT, and 34 patients (34.7%) received whole liver grafts. The age range of the deceased donors was 3 months to 56 years and that of pediatric recipients was 7 months to 17 years. Common primary diseases for LT were biliary atresia in 13, acute liver failure in four, Wilson disease in four, congenital portal vein agenesis in three, and genetic metabolic diseases in three. Pediatric-to-pediatric and adult-to-pediatric whole LTs were 22 (64.7%) and 12 (35.3%), respectively. A good correlation was noted between the donor and the recipient's body weight, and the recipient's body weight and allograft's weight. Graft and overall patient survival rates were 91.2% and 91.2% at 1 year, 88.0% and 88.0% at 3 years, and 88.0% and 88.0% at 5 years, respectively.

Conclusions

The results of this study revealed that Korean Network for Organ Sharing (KONOS) regulations with donor-recipient body weight matching exhibited good performance. Considering the reciprocal trades of liver organs among pediatric and adult donors and recipients, it is necessary to establish a policy for pediatric donor liver grafts to pediatric recipients on a priority basis.

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.

Korea-nationwide incidence of pediatric deceased donors and single-institutional status of liver transplantation using pediatric donor liver grafts

Background

The present study intended to investigate the allocation status of pediatric deceased donor liver allografts. We analyzed the incidence of pediatric deceased donors in the Korean Network for Organ Sharing (KONOS) database and single-institutional status of liver transplantation (LT) using pediatric donors.

Methods

We assessed the nationwide incidence of pediatric donors aged ≤15 years and conducted single-center analysis of LT using pediatric donors.

Results

Between 2010 and 2019, pediatric donors aged ≤15 years accounted for 171 out of 4,395 donors (3.9%) in the KONOS database and 31 out of 640 liver donors (4.8%) in Asan Medical Center (AMC) database. In AMC, 11 (35.5%) and 20 (64.5%) grafts were allocated to pediatric recipients aged ≤15 years and adult recipients aged ≥19 years, respectively. All nine livers from donors aged ≤5 years were implanted in pediatric recipients aged ≤5 years. From 21 donors aged ≥9 years, 16 whole liver grafts and four split extended right liver grafts were implanted in 20 adult recipients and two split left lateral section grafts were implanted in two pediatric recipients. Four split liver grafts were implanted in other institutions. The overall patient survival rates at 1, 3, and 5 years were 90.9%, 80.8%, and 80.8%, respectively in pediatric-to-pediatric LT group and 69.6%, 58.4%, and 58.4%, respectively in pediatric-to-adult LT group (P=0.21).

Conclusions

More than half of the pediatric donor livers were allocated to adult patients. Recipient criteria for allocation of liver allografts from pediatric donors need revision for children on pediatric LT waitlist.

Living-donor liver transplantation with hyperreduced left lateral segment grafts: a single-center experience

BACKGROUND

In the setting of liver transplantation in small infants who receive left lateral segment (LLS) grafts, problems are encountered related to graft-size mismatching in the form of so-called "large-for-size" grafts. To address these problems, the feasibility of further reducing the size of LLS grafts to form hyperreduced LLS (HRLLS) grafts was investigated.

METHODS

Of the 175 pediatric living-donor liver transplantations performed between November 2005 and December 2011 at our institute, 31 cases were performed using HRLLS grafts. The medical records were reviewed and data were collected retrospectively.

RESULTS

The graft-to-recipient body weight ratio was successfully reduced from 5.2% ± 2.0% to 2.9% ± 0.5%. Portal vein thrombosis was observed in one case, and biliary stenosis was seen in two cases. No hepatic artery thrombosis was encountered. The graft and patient 2-year survival rate was 87%. When the results categorized according to the original disease were verified, patients with fulminant hepatic failure (FHF) weighed less and had smaller abdominal cavities compared with patients with cholestatic or metabolic disease. Patients with FHF frequently required skin or partial skin closure to avoid graft compression. For this reason, the anteroposterior diameters in the recipients' abdominal cavities were not adequately large to accommodate the graft thickness, especially in patients with FHF.

CONCLUSIONS

In conclusion, living-donor liver transplantation using HRLLS grafts offers a safe and useful option for treating smaller infants.

Multivisceral transplantation using a 2.9 kg neonatal donor

Prematurity and very low birthweight have often been considered relative contraindications to neonatal organ donation. Organ procurement from neonatal donors is further complicated by unclear guidelines regarding neonatal brain death. We report a successful case of multivisceral transplantation using a graft from a 10-day-old, 2.9 kg, neonatal donor born at 36 6/7 wk in a 3.2 kg, three month old with intestinal and liver failure secondary to midgut volvulus. There was immediate liver graft function with correction of recipient coagulopathy, but delayed normalization of laboratory values and delayed return of bowel function. At six-yr post-transplant follow-up, the patient has normal intestine and liver function. Her last histologically confirmed rejection episode was 30 months prior to last follow-up. This case suggests that multivisceral grafts from very young or small neonatal donors may be transplanted successfully in selected cases. We propose a re-examination of the brain death guidelines for premature and young infants to potentially increase the availability of organs for infant recipients.

Portal vein reconstruction in pediatric living donor liver transplantation for patients younger than 1 year with biliary atresia

BACKGROUND/PURPOSE

Infants with biliary atresia undergoing living donor liver transplantation (LDLT) are at increased risk of portal vein (PV) complications because of their smaller vascular caliber and sclerosis because of previous Kasai portoenterostomy and recurrent cholangitis.

METHOD

Of 154 children who underwent transplantation between November 2005 and January 2011, 34 with biliary atresia received a transplant while younger than 1 year. Six patients underwent PV reconstruction with an interposition vein graft, and the others underwent the branch patch technique. The clinical characteristics of those who underwent the interposition reconstruction or the branch patch technique were compared, and the PV complications were assessed.

RESULTS

Portal vein complications occurred in 5 patients (14.7%) in the branch patch group. There were 4 patient deaths, and all of them had received branch patch reconstruction. The branch patch reconstruction cases with a sclerotic small caliber (<4 mm) determined by using preoperative ultrasonography showed a significantly high mortality rate (44.4%). All patients with interposition vein graft reconstruction are still alive with excellent graft function without anticoagulation therapy.

CONCLUSION

The interposition vein graft appears to be a feasible option with better graft survival and less PV complications when performing LDLT for biliary atresia in infants younger than 1.

Living donor liver transplantation with hyperreduced left lateral segments

Liver transplantation is now an established technique to treat children with end-stage liver disease. Implantation of left lateral segment grafts (Couidaud's segments II and III) can be a problem in small infants because of a large-for-size graft. Reduced left lateral segmental liver transplantation has been recently introduced for small infants to mitigate the problem of large-for-size graft. Further reduction of the left lateral segment graft increases the possibility of supplying an adequate hyperreduced left lateral segment graft as an alternative surgical technique. We report 3 cases of our experience of transplantation using hyperreduced left lateral segment grafts from living donors.

Effect of the immunosuppressants on hepatocyte cells proliferation and apoptosis during liver regeneration after hepatectomy - molecular studies

The regeneration and remodeling of the transplanted liver is the result of hepatocyte proliferation and apoptosis (programmed cell death). The purpose of this study was to verify the influence of immunosuppressants on the expression levels of genes: IL-6 (regulator of hepatocyte proliferation), pro-apoptotic (Bak and Bax) and anti-apoptotic (Bcl-Xl and Bcl-2). 36 newborn suckling rats (age 5-7 days, weight 6-10 g) were divided into four groups: hepatectomy, hepatectomy plus methylprednisolone, hepatectomy plus CsA and hepatectomy plus Tac. The same experiments were performed in 24 weaning rats (age 21-23 days, weight 30-50 g). The animals were killed one day after the hepatectomy and the remnant livers were analyzed. The livers of all animals exhibited histological changes of liver regeneration. The immunosuppressants did not promote any alteration on IL-6 gene expression levels. Methylprednisolone and CsA increased the expression levels of Bak gene in newborn rats. However, methylprednisolone and Tac promoted increased expression levels of Bcl-2 in all groups. We hypothesize that these effects explain the efficacy of these drugs on the treatment of acute and chronic liver rejection as the expression of Bcl-2 in cholangiocytes is decreased as a consequence of bile duct lesions

Experimental models of hepatectomy and liver regeneration using newborn and weaning rats

OBJECTIVES

Liver regeneration is a complex process that has not been completely elucidated. The model most frequently used to study this phenomenon is 70% hepatectomy in adult rats; however, no papers have examined this effect in developing animals. The aims of the present study were: 1) to standardize two models of partial hepatectomy and liver regeneration in newborn suckling and weaning rats, and 2) to study the evolution of remnant liver weight and histological changes of hepatic parenchyma on the days that follow partial hepatectomy.

METHODS

Fifty newborn and forty-four weaning rats underwent 70% hepatectomy. After a midline incision, compression on both sides of the upper abdomen was performed to exteriorize the right medial, left medial and left lateral hepatic lobes, which were tied inferiorly and resected en bloc. The animals were sacrificed on days 0 (just after hepatectomy), 1, 2, 3, 4 and 7 after the operation. Body and liver weight were determined, and hepatic parenchyma was submitted to histological analysis.

RESULTS

Mortality rates of the newborn and weaning groups were 30% and 0%, respectively. There was a significant decrease in liver mass soon after partial hepatectomy, which completely recovered on the seventh day in both groups. Newborn rat regenerating liver showed marked steatosis on the second day. In the weaning rat liver, mitotic figures were observed earlier, and their amount was greater than in the newborn.

CONCLUSIONS

Suckling and weaning rat models of partial hepatectomy are feasible and can be used for studies of liver regeneration. Although similar, the process of hepatic regeneration in developing animals is different from adults.