A Fatal Complication Following Hybrid Total Arch Replacement with Supra-aortic Artery Translocation and Endovascular Stenting

This case highlights the successful management of acute Type B dissection complicated by visceral malperfusion. Even though the procedure of hybrid supra-aortic translocation and endovascular stenting corrected the malperfusion, it is important for vigilant CT scan surveillance for the post operative complications which can occur with this procedure.

A 56 year old female was admitted with history of sudden onset chest pain. Acute coronary syndrome was suspected but angiography revealed a type B dissection confirmed on CT scanning (Fig. 1). Medical management was initiated but on day 9 post-event she complained of further back pain and was noted to have deteriorating renal and liver function and haematuria. A repeat CT scan demonstrated partial right renal and liver ischaemia due to malperfusion (Fig. 2A). The type B dissection arose immediately adjacent to the left subclavian artery and the supra-aortic vessels arose in close proximity (Fig. 1). Endovascular stent grafting was considered but stent deployment could only satisfactorily occur in Zone 0 because of the supra-aortic anatomy and arch curvature. A hybrid operation was performed comprising total supra-aortic vessel translocation using the three side-arms of a Gelweave Vascutek Plexus (Vascutek Ltd, Renfrewshire, UK) aortic arch graft with the patch anastomosed to the proximal ascending aorta using a side-biting clamp without utilising cardiopulmonary bypass (Fig. 3). A 38 mm Medtronic Valient stent graft (Medtronic Limited, Hertfordshire, UK) was then satisfactorily deployed via the femoral artery from zone 0 to zone 3. The initial recovery was uneventful with resolution of pain, normalisation of renal function and improved kidney perfusion on check CT scanning done immediately postop (Fig. 2B). On post-operative day 14, the patient collapsed with an electromechanical cardiac arrest from which she could not be resuscitated. Post-mortem examination demonstrated a type A dissection with intra-pericardial rupture. A review of the check CT scan revealed an intimal tear in the proximal ascending aorta (Fig. 3 A, B); this was initially perceived to be related to the patch graft insertion.

Endovascular stent grafting is rapidly becoming a treatment of choice for complicated type B dissection. Supra-aortic vessel translocation to allow secure stent deployment is sometimes necessary. However, the non-dissected aorta may also be abnormal in such patients and this case illustrates the need for great caution and vigilance in post-operative CT scan assessment to ensure that iatrogenic aortic injury is prevented or detected.