Fenestrated/branched endovascular aneurysm repair (F/BEVAR) is associated with high technical success and low mortality in patients with chronic post-dissection thoracoabdominal aortic aneurysm (PD-TAAA). This conclusion was presented by Mohamed A Abdelhalim (St Thomas’ Hospital, London, UK), who detailed a multicentre, transatlantic experience with F/BEVAR for chronic PD-TAAAs during this year’s Society for Vascular Surgery (SVS) Vascular Annual Meeting (VAM 2022; 15–18 June, Boston, USA).
The study was co-authored by Emanuel R Tenorio and Gustavo Oderich (both The University of Texas Health Science Center at Houston, Houston, USA) alongside senior author Bijan Modarai (Guy’s and St Thomas’ NHS Foundation Trust, London, UK).
“F/BEVAR has been used widely in the treatment of thoracoabdominal aneurysms,” Abdelhalim told attendees of the morning session, adding that PD-TAAAs present a unique set of endovascular technical challenges.
The study aimed to analyse outcomes of F/BEVAR for treatment of chronic PD-TAAAs by reviewing clinical data of consecutive patients treated by F/BEVAR for Extent I-III PD-TAAAs in 16 centres from the USA and Europe from 2008‒2021. All patients received off-the-shelf or patient-specific manufactured fenestrated-branched stent grafts.
Endpoints for the study included any-cause mortality and major adverse events (MAEs) at 30 days, technical success, target artery (TA) patency, freedom from TA instability, minor (endovascular with <12Fr sheath) and major (open or >12Fr sheath) secondary interventions, and patient survival and freedom from aortic-related mortality (ARM).
Abdelhalim presented data from 246 patients (76% male; median age 67 years [interquartile range (IQR) 61‒73]), who were treated for Extent I (7%), Extent II (57%) and Extent III (36%) PD-TAAAs (Median aneurysm diameter, 65mm [IQR 59‒73]) by F/BEVAR. Of these, 18 patients (7%) were octogenarians, 212 (86%) were American Society of Anaesthesiologists (ASA) class ≥3, and 21 (9%) presented with contained ruptured or symptomatic aneurysms.
Abdelhalim reported that there were 917 renal-mesenteric vessels targeted by 581 fenestrations (63%) and 336 directional branches (37%), with a mean of 3.7 vessels per patient. He noted that technical success of the procedure was 96%.
The author reported that the study investigators found “favourable” 30-day mortality among the patient cohort, with a rate of around 3%, whilst adding that MAEs occurred in 28%, including acute kidney injury in 8%, new-onset dialysis in 1%, major stroke in 1%, spinal cord injury in 7% and permanent paraplegia in 2%, he noted. Mean follow-up was 24±23 months, wherein patient survival and freedom from ARM were 65±10% and 93±5% at five years, respectively.
Secondary interventions were needed in 93 patients (38%), Abdelhalim noted, including minor procedures in 63 (26%) and major in 30 (12%). There was one conversion to open repair (<1%), while freedom from any secondary intervention was 44±9% at five years. The five-year freedom from target artery instability was 82±3% and instability was significantly more likely to affect branches than fenestrations.
Major causes included endoleaks and stenosis, the presenter commented. In his concluding remarks, Abdelhalim noted that F/BEVAR was associated with high technical success and low mortality (3%), new-onset dialysis (1%) and permanent paraplegia rates (2%) in patients with chronic PD-TAAAs.
Although the procedure is effective against ARM, he commented, overall patient survival at five years (65%) reflects the fact that patients treated have advanced age and significant comorbidities. Freedom from secondary interventions at five years was 44%, although most were minor procedures and conversion to open repair was needed in only one patient.
“Fenestrated and branched EVAR can be used in the treatment of chronic post-dissection aneurysms with low mortality and low morbidity,” Abdelhalim said. “However,” he cautioned, “this does carry a significant intervention rate, and because of this, a bespoke approach is required for each patient, and this includes close follow-up and monitoring of the long-term outcomes.”
The importance of long-term follow-up was a theme picked up in the discussion following the presentation, during which a number of audience members remarked on the significance of the data presented by Abdelhalim.
Speaking from the floor, Ian Loftus (St George’s University Hospital NHS Foundation Trust, London, USA) described these as “really important data” and echoed the point that long-term outcomes are key.
“You have highlighted that these are very sick patients and it is very complex technology, and therefore is very expensive and time consuming,” remarked Loftus. “How do you think that we can prove that we are altering long-term outcomes for these patients, and how are we going to prove cost-effectiveness of these technologies?” he asked.
“The follow-up in this cohort is two years, so the only way to do that is for us to continue monitoring these patients and see where we are in a number of years from now,” Abdelhalim responded.
Study co-author Oderich, who joined Abdelhalim at the podium for the discussion, further remarked: “I think what this shows is that we selected a very high-risk population, and that reflects the fact that it is the beginning of the experience with fenestrated-branched grafting. “As time goes by and we enrol patients that are intermediate or lower risk, I think we will be able to achieve a longer follow-up.”