A retrospective review of all endovascular interventions for HAS after liver transplantation that occurred between June 2013 and November 2020 was performed at a single institution that performs 70–80 liver transplants per year.
The patients were selected utilizing a procedural database (X-plore) using the different keywords (stenting, hepatic artery, transplant, liver, PBA).
Approval for this retrospective review study was obtained from the institutional review board.
To provide the optimal treatment for the patients, we used a score that combines the following criteria (Kodama et al., 2006; Hamby et al., 2013):
A significant artery stenosis was suspected when typical tardus parvus pattern, defined by a RI < 0.5 and SAT > 10 ms, was identified in the hepatic parenchyma (left, right lobe or both) associated or not with a PSV > 200 cm/s Fig. 1.
During the follow-up, all patients had Us exploration (every 3 months). When a significant stenosis was suspected a CT or MRI was systematically realized to confirm or unconfirm the stenosis.
Hepatic artery stenosis was defined as focal diameter narrowing of the hepatic artery measuring > 70% by visual estimate (Sabri et al., 2011).
Initial technical success was defined as < 30% residual stenosis of the treated hepatic artery by visual estimation of the final arteriogram (Hamby et al., 2013). Neither intravascular ultrasound imaging nor pressure gradients were used in this series. Follow up occurred from 1 month to 4 years (median 15 months).
Early stenosis was defined as a stenosis appearing within 30 days after transplantation and late stenosis after 30 days.
Primary patency was defined as the duration of patency without revision, and primary assisted patency was defined as the duration of patency after successful revision.
Endovascular reintervention was define by the recurrence of a significant stenosis during the follow up and the necessity of restenting or doing a new percutaneous angioplasty.
The decision to intervene was based exclusively on imaging studies after multidisciplinary consultation meeting.
PBA alone was used if < 30% residual stenosis of the hepatic artery was achieved. Stenting was performed if there was greater than 30% residual stenosis and in the case of complications (dissection or rupture) (Hamby et al., 2013).
Endovascular therapies and technique
The treatment consisted of dilating with balloon or stent. We analyzed short-term (technical success and complications) and long-term outcomes (liver function, arterial patency, graft survival at 12 months (GS), and reintervention). We also compared percutaneous balloon angioplasty (PBA) with stent placement or both procedures.
In brief, A 6-F introducer sheath was placed in the common femoral artery. A 6F renal double curve catheter (RDC, Boston Scientific) and a 0.035 guide wire (Terumo Medical Corp.) were used to select the celiac trunk or superior mesenteric artery. Then, the guide wire was placed in the gastroduodenal artery or distal common hepatic artery, and a 5F Cobra catheter (Terumo Medical Corp.) was advanced for more support. A 0.014-in. or 0.0016-in. guide wire was used to cross the lesion with or without a microcatheter, depending on the difficulty of crossing the stenosis. All patients received therapeutic weight-based bolus heparin (50 u/kg) at the beginning of the procedure. Subsequent stenting was selectively performed when stent placement was technically feasible and in cases of > 30% residual stenosis after angioplasty. Balloon-expandable (Palmas Blue, Cordis, Switzerland) or rebel (Boston Scientific, Marlborough, Massachusetts) stents were used. Initial balloon (ussv, boston scientific) sizing was conservative (4-5 mm), generally choosing a diameter thought to be at least 1 mm smaller than the reference vessel. Larger balloons were then used as needed to match the reference vessel. Stent diameters were also chosen to match the reference vessel without oversizing.
For our study to be reproductible, we used the CIRSE classification to grade the complications (Filippiadis et al., 2017).
Ultrasound imaging was performed on all treated patients at 1–7 days, 3 months, 6 months, 12 months and yearly thereafter, if no stenosis was detected. More frequent follow up was conducted if a small recurrent stenosis was detected.
We defined three groups of patients: group1 (patients treated only by PBA), group 2 (patients treated only by stenting precessed or not by PBA) and group 3 (patients treated by stenting and PBA after stenting).
All patients received dual antiplatelets: group 1 (with PBA only) received long-term acetylsalicylic acid and clopidogrel for 6 weeks. Groups 2 and 3 (with stents) received lifelong acetylsalicylic acid and clopidogrel for 1 year.
Statistical analysis
Chart review was used to determine graft survival and identify additional interventions or complications during the follow up period. Primary, primary-assisted patency, and graft survival rates were recorded and analyzed using survival analysis using the Kaplan-Meier method.
The Chi2 test was used for comparisons among the three groups. A p value < 0.05 was considered statistically significant. The statistical analysis was performed using SPSS software (version 24; SPSS, Chicago, IL).