Donor‐to‐recipient weight ratio is a risk factor for hepatic artery thrombosis after whole‐liver transplantation in children under 25 kg

Abstract

Hepatic artery thrombosis (HAT) following pediatric liver transplantation increases morbidity and risk of graft failure. We performed a retrospective chart review of all patients who underwent deceased‐donor liver transplantation from August 2002 to July 2016. Multi‐organ transplant recipients were excluded. We examined the incidence of HAT at our institution and sought to identify associated donor or recipient risk factors. A total of 127 deceased‐donor liver transplant patients with a median age of 1.7 years (IQR 0.67‐6.7) were identified. Of those, 14 developed HAT, all weighing under 25 kg. Among 100 patients under 25 kg, whole‐liver graft recipients had an odds ratio of 3.98 (95% confidence interval [CI]: 1.03, 15.34; P = .045) for developing HAT compared with split‐liver graft recipients. Within the whole‐liver recipient group under 25 kg, 11 patients developed HAT with a median donor‐to‐recipient ratio (DRWR) of 0.9 (IQR: 0.7‐1.2) compared with a median DRWR of 1.4 (IQR: 1.1‐1.9) for those who did not develop HAT. Multivariate analysis showed DRWR to be an independent risk factor for HAT in patients weighing under 25 kg who received whole organ grafts, with an odds ratio of 3.89 (95% CI: 1.43, 10.54; P = .008) for each 0.5 unit decrease in DRWR. Our results suggest that in recipients under 25 kg 1) split‐liver grafts may have a lower rate of HAT and 2) selecting whole organ donors with a higher DRWR may decrease the incidence of HAT.

Impact of allograft types on outcomes after pediatric liver transplantation due to biliary atresia

“…The incidence of HAT is reported to be between 3.2% and 5% in LDLT recipients, 6.7% in SLT recipients, 33 and 9.3% in WLT recipients 34 . Several investigators have identified the combination of a lower weight and a whole‐liver allograft as placing individuals at particularly high risk (approximately 12%) for HAT, 35,36 and the WLT group reflected a higher incidence of HAT complications in our study, with up to 16.16%—with 2.56% in SLT and 0.49% in LDLT. HAT was thus the independent risk factor that could heighten allograft loss 8.36‐fold.…”

“…The incidence of HAT is reported to be between 3.2% and 5% in LDLT recipients, 6.7% in SLT recipients, 33 and 9.3% in WLT recipients. 34 Several investigators have identified the combination of a lower weight and a whole-liver allograft as placing individuals at particularly high risk (approximately 12%) for HAT, 35,36 TA B L E 5 Single-factor analysis of allograft loss authors hypothesized that technical-variant grafts typically came from larger donors with larger vessels, decreasing distal resistance in the hepatic artery and decreasing the risk of HAT. 34 The choice of artery to be anastomosed and surgical skill may also exert an influence on HAT, but we did not pursue these aspects in the current study.…”

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

“…[34] The lower incidence of HAT in technical variant grafts may be due to the fact that the nature of large vascular liver is different from that of small whole liver, with larger volume and smaller possibility of portal hyperperfusion. [25] F I G U R E 3 The Kaplan-Meier probability of patient survival In our study, the average weight of LLS recipients in the SLT ≤ 25 kg group was 6.6 kg, the minimum weight was 4.8 kg, and the maximum weight was 7.9 kg. Although there was no significant difference in the incidence of HAT between the SLT ≤ 25 kg group and the other three groups, two cases of HAT in the LLS recipients remind us to pay attention to donor selection criteria and BW, because in the study we reported earlier, [8] the LLS recipients did not develop HAT due to stricter selection criteria and slightly larger donor BW.…”

“…However, the interaction between these two variables has not been well characterized 21,22. At present, it is generally believed that HAT occurs more frequently in whole‐liver recipients and in smaller patients 23–27. Previous studies have found that the combination of a young recipient and a whole‐liver allograft leads to a particularly high risk (25%–29%) for HAT 28,29.…”

“…[21,22] At present, it is generally believed that HAT occurs more frequently in whole-liver recipients and in smaller patients. [23][24][25][26][27] Previous studies have found that the combination of a young recipient and a whole-liver allograft leads to a particularly high risk (25%-29%) for HAT. [28,29] Alexopoulos et al reported that recipients of a whole-liver allograft with BW ≤ 7 kg had the highest rate of vascular thrombosis contributing to graft failure and the highest rate of retransplantation compared with technical variant grafts.…”