Study finds no correlation between TEVAR timing and uncomplicated type B aortic dissection outcomes

With proper patient selection, short-term outcomes of thoracic endovascular aortic repair (TEVAR) in acute uncomplicated acute type B aortic dissection (uTBAD) are similar irrespective of the timing of treatment after dissection. This is according to a study recently published in the Journal of Vascular Surgery (JVS).

Authors Adam W Beck (University of Alabama at Birmingham, Birmingham, USA) and colleagues write in their introduction that the timing of TEVAR after the onset of uTBAD “remains controversial”. The objective of the present study, against this backdrop of contention, was to evaluate the Society for Vascular Surgery (SVS) Vascular Quality Initiative (VQI) post-approval study (VQI PAS) data for the impact of TEVAR timing for uTBAD on early and late outcomes. These included mortality, procedural complications, and long-term reintervention.

The investigators note that the VQI PAS used for this analysis includes a total of 606 patients. Those patients with uTBAD—who were defined as those without rupture or malperfusion—exclusive of cases categorised as emergency (n=206), were divided into groups defined by the SVS/Society of Thoracic Surgeons reporting guidelines based on the timing of treatment after the onset of dissection. The three groups were: treatment within 24 hours (n=8), between one and 14 days (n=121) and between 15 and 90 days (n=77). The researchers used univariate and multivariable analysis to determine differences between timing groups for postoperative mortality, inhospital complications and reintervention.

Demographics and comorbid conditions were “very similar” across the three TEVAR timing groups, Beck et al detail. The authors state that there were some “notable differences” between the groups, including higher prevalence of baseline elevated creatinine (>1.8mg/dL)/chronic end-stage renal disease and designation as ‘urgent’ in the <24-hour group, as well as a higher rate of preoperative ß-blocker therapy in the one- to 14-day group.

The authors report that postoperative stroke, congestive heart failure and renal ischaemia were authors elaborate that this may include changes in medical management of patients prior to surgery—including preoperative thrombolysis or antiplatelet therapy—as well as changes in periprocedural routines, such as use of different techniques for cerebral monitoring during carotid surgery. more common in the <24-hour group without an increase in mortality.

In addition, the researchers recognise that the Swedevasc registry did not include data on arteriotomy length, width of internal carotid artery, type of anaesthesia and intracerebral vessel, and as a result, “these variables were not corrected for”.

Primary closure “remains common practice” by some Considering the wider importance of their research, the authors write that their study “underlines the variation in surgical techniques used for CEA in Sweden,” underscoring the fact that up to 20% are operated on with primary closure without patch.

Jonsson et al reiterate in their conclusion that, due to its association with an increased risk of postprocedural stroke, the technique “should not be used”. In addition, they note the current report underlines the fact that selective primary closure “remains common practice” by some surgeons, and stress that “further educational efforts to move towards routine patch closure or eversion endarterectomy among all carotid surgeons are warranted”.

Unadjusted 30-day mortality across the groups, they continue, was lowest in the early TEVAR group (0%, 3.3% and 5.2%; p=0.68), as was the one-year mortality (0%, 8.3% and 18.2%; p=0.06). However, they add the caveat that these results were not statistically different at any time point.

Furthermore, Beck and colleagues reveal that reintervention out to three years was not different between the groups, and that multivariable analysis demonstrated the need for a postoperative therapeutic lumbar drain to be the only predictive risk factor for mortality (hazard ratio=7.595, 95% confidence interval: 1.73–33.337, p=0.007).

In the conclusion of their study, Beck et al acknowledge that patients with uTBAD treated within 24 hours were unusual (n=8) and the group was “too small for valid statistical comparison”. They add that these patients “likely represent a high-risk subgroup, which is manifested in a higher risk of complications”.

Although there was a “trend” toward improved survival in the acute (one- to 14-day) phase, the researchers summarise that outcomes did not differ compared with the subacute (15- to 90-day) phase with relation to early mortality, postoperative complications, or one-year survival. They state in closing: “These data suggest that the proper selection of patients for early TEVAR can result in equivalent survival and early outcomes.”