Thrombosis prophylaxis in pediatric liver transplantation: A systematic review

Table 1 Summary of findings of the nine included studies

Reference	Country	Population (n)	Study design	Method used for diagnosis and follow-up duration	Intervention	Outcome	Main results
Sabra et al[37]	Japan	113 pediatric LDLT	Retrospective	Doppler US twice daily till 1st week. If any PV complications were found, specific tests such as angiography were performed 1 yr of follow-up	PV reconstruction with VG (31 pts) PV reconstruction with EEA (82 pts)	Preoperative recipient factors PVT incidence Pt survival Graft survival	Global incidence PVT (2.6%) in the first 3 mo after OLT 1 PVT in 31 VGs vs 2 PVT in 82 without VGs No significant difference for PVT, Pt survival, Graft survival In the two groups
Julka et al[38]	Taiwan	87 pediatric LDLT	Retrospective	Routine doppler US post LT; CT angiography for HAT confirmation 5 yr of follow-up	HA reconstruction with two arterial stumps. 2 HA stumps with 2 HA reconstruction = 20 pts 2 HA stumps with 1 HA reconstruction = 22 pts 1 HA stump with 1 HA reconstruction = 45 pts	HAT incidence BC incidence	Overall HAT incidence 6.9% The incidence of HA thrombosis and biliary complications was similar in the three groups
Saad et al[39]	Japan	110 LDLT in pediatric pts	Retrospective LDLT	Doppler US, performed routinely before, during and after surgery Follow-up not defined	Different types of portal vein reconstructions Type 1: End- to- end anastomosis = 36 pts Type 2: Branch patch anastomosis = 27 pts Type 3: Anastomosis to the confluence (superior mesenteric vein-splenic vein) = 16 pts Type 4: Vein graft = 32 pts Chosen according to the surgical evaluation	C TC SC Survival rate	Type 1: 1 SC / 36 pts Type 2: 2 TC / 27 pts Type 3: 0 / 16 pts Type 4: 1 TC / 32 pts Overall survival rate 86%
Shackleton et al[31]	California	194 pediatric OLT for biliary atresia (mixed LDLT and DDLT)	Retrospective	Clinical suspect confirmed by angiography and/or surgical exploration. 3 yr of follow-up	Gr 1: Conventional artery reconstruction (n = 166) Gr 2: MHR (n = 28)	Risk factors for HAT Impact of MHR on incidence of HAT, need of re-OLT, patient and graft survival	Impact of MHR HAT incidence: Gr 1 32/166 (19%) vs Gr 2 0/28 (0%), P = 0.006 Re-OLT: Gr 1 31/166 (19%) vs Gr 2 1/28 (4%), P = 0.05 1 yr actuarial survival: Gr 1 81% vs Gr 2 100%, P = 0.02 (univariate analysis) BUT P = 0.076 in step wise Cox regression for patient survival
López et al[32]	Spain	104 OLT in 82 pediatric pts (mixed LDLT and DDLT)	Retrospective	Doppler US routinely and selective arteriography for confirmation. 3 yr of follow-up	Arterial revascularization technique: Gr 1 (n = 48) AhG Gr 2 (n = 56) EEA Chosen according to the surgical evaluation	HAT incidence Survival rate	HAT incidence Gr 1. (AhG): 6.25% Gr 2. (EEA): 8.92% (P not significant) Graft Survival rate (1 yr) 61.5% (AhG) vs 60% (EEA) (P < 0.05) Graft survival rate (5 yr): 77.5% (AhG) vs 75.1% (EEA) (P < 0.05)
Millis et al[33]	Illinois	66 pediatric LDLT and 48 pediatric cadaveric RLT	Retrospective	Doppler US every day for the first 3 d and at 1, 3, 6, 12, 18, and 24 mo after transplantation + angiography for confirmation 5 yr of follow-up	Portal anastomosis with venous graft conduit in LDLT Gr 1 (n = 18): Native reconstructed vein Gr 2 (n = 37): Cryopreserved iliac vein; Gr 3 (n = 11): Cryopreserved femoral vein	Incidence of PVC Graft survival Patient survival	Incidence PVC LDLT 33/66 (50%) vs RLT 4/48 (8%) P < 0.0001 Early PVT LDLT Gr 1: 6 (33%)a LDLT Gr 2: 3 (8%) LDLT Gr 3: 1 (9%) RLT: 2 (4%) aP < 0.005 vs RLT Late PVC LDLT Gr 1: 3 (16%) LDLT Gr 2: 19 (51%)a LDLT Gr 3: 1 (9%) RLT: 2 (4%) aP < 0.005 vs RLT; P < 0.02 vs Gr 1 and Gr 3 Graft survival PVC: 61% No PVC: 67%, P = NS Patient survival: PVC: 67% No PVC: 71%, P = NS
Jurim et al[34]	California	35 pediatric OLT Emergency transplants only (type of donor not specified)	Retrospective	Not reported. Follow-up not defined	Gr 1: RLT = 7 pts Gr 2: Whole graft = 18 pts	HAT incidence Incidence of other complications: Biliary; bleeding; chronic rejection	HAT: Gr 1:0 (0%)/Gr 2:5 (29%) (P < 0.05) The incidence of biliary complications, bleeding (requiring surgical exploration) and chronic rejection were similar between the groups
Yandza et al[35]	France	143 DDLT in 122 pediatric pts	Retrospective	Doppler US daily the first 15 d, twice/wk until discharge Follow-up not defined	Gr 1 (n = 41 pts, n = 50 grafts) children < 10 kg Gr 2 (n = 81 pts, n = 93 grafts) children > 10 kg Surgical technique: EEA vs AhG	Effect of the site of liver graft arterial inflow on HAT incidence according to the recipient weight	Overall HAT incidence: 14/143 (10%) HAT incidence between the 2 groups: Gr 1: 6/50 (12%) vs Gr 2: 8/93 (9%), P not significant; Gr 1 EEA 5/31 (16%) vs Gr 1 AhG 1/19 (5%); P not significant Gr 2 EEA 4/60 (6%) vs Gr 2 AhG 4/32 (12%) P not significant
Stevens et al[36]	Chicago	134 OLT in 100 pediatric pts < 2 yr : mixed LDLT and DDLT	Retrospective	Doppler US, frequency not defined Follow-up	60 standard whole liver vs 74 RLT (13 LDLT) Surgical technique: Arterial inflow with 83 hepatic artery vs 32 celiac artery vs 5 supraceliac aorta vs 27 infrarenal aorta vs 7 unusual reconstruction	Effect of the graft type and site of arterial inflow on the Incidence of HAT	HAT incidence in 25% whole liver transplant vs 23% in LDLT vs 15% RLT (P = 0.06) Aortic anastomosis (supraceliac and infrarenal) reduces incidence of HAT (6% vs 24%, P = 0.02)

BA: Biliary atresia; BW: Body weight; CTA: CT angiography; Gr: Group; GRWR: Graft-to-recipient weight ratio; HAG: Hepatic artery graft; LT: Liver transplantation; OLT: Orthotopic liver transplantation; Pt: Patient; RLT: Reduced size liver transplantation; re-OLT: Re-transplantation; SC: Stenotic complication; TC: Thrombosis complication; US: Ultrasonography; LDLT: Living donor liver transplantation; PV: Portal vein; VG: Vein graft; EEA: End-to-end anastomosis; PVT: Portal vein thrombosis; HAT: Hepatic artery thrombosis; HA: Hepatic artery; BC: Biliary complications; C: Complications; MHR: Microsurgical hepatic arterial reconstruction; AhG: Aortohepatic interposition graft; PVC: Portal vein complications; DDLT: Deceased donor liver transplantation.