Ultrasound guidance “should be routine” for transfemoral TAVI access

Adrian Banning

Ultrasound-guided transfemoral transcatheter aortic valve implantation (TAVI) is associated with a significant reduction in the risk of access site vascular and bleeding complications, compared to a fluoroscopy-guided strategy, a systematic review and meta-analysis comparing the two approaches has concluded.

The results of the analysis support the routine adoption of ultrasound to guide primary access in TAVI as a tool that can modify the risk of vascular and bleeding complications, the study’s authors suggest.

Led by senior author Adrian Banning (Oxford Heart Centre, John Radcliffe Hospital, Oxford, UK) and colleagues, the review published in Circulation: Cardiovascular Interventions compared access site vascular and bleeding complications according to the Valve Academic Research Consortium-2 classification following the use of either ultrasound- or conventional fluoroscopy-guided transfemoral TAVI access.

Ultrasound-guided transfemoral access has been proposed as an alternative strategy to reduce access site complications, Banning et al write, noting that it offers realtime, cross-sectional visualisation of the puncture site anatomy, reducing accidental vascular injury and enhancing the efficacy of vascular closure devices.

However, despite being recommended by some interventional society guidelines, there are currently no conclusive data confirming whether an ultrasound-guided strategy confers superior outcomes to a fluoroscopic-guided technique.

The review sought to assess the evidence for access site vascular and bleeding complication rates comparing the use of either modality to guide transfemoral access in TAVI. The authors selected studies that compared ultrasound and fluoroscopy-guided transfemoral access, with two groups of participants pertaining to each intervention from the Medline, Embase, Web of Science, and the Cochrane Library. A priori defined primary outcomes were extracted including: major, minor, and major and minor (total) access site vascular complications, life-threatening/major, minor, and  life-threatening, major, and minor (total) access site bleeding complications.

Banning and colleagues included eight observational studies in their review, involving a total of 3,875 participants. The studies had a mean participant age of 82.8 years, Society of Thoracic Surgeons (STS) score of 5.81, and peripheral vascular disease was present in 23.5%.

The study team reports that an ultrasound-guided approach was significantly associated with a reduced risk of total (Mantel-Haenszel odds ratio [MH-OR], 0.50 [95% CI, 0.35–0.73]), major (MH-OR, 0.51 [95% CI, 0.35–0.74]), and minor (MH-OR, 0.59 [95% CI, 0.38–0.91]) access site vascular complications.

Ultrasound guidance was also significantly associated with total access site bleeding complications (MH-OR, 0.59 [95% CI, 0.39–0.90]). The association remained significant in sensitivity analyses of maximally adjusted minor and total vascular access site complications (MH-OR, 0.51 [95% CI, 0.29–0.90]; MH-OR, 0.44 [95% CI, 0.20–0.99], respectively).

Discussing the findings, the study team write that although the study synthesises data from low-moderate quality studies, sensitivity analysis including including maximally adjusted results shows that ultrasound guidance is associated with a significant 56% reduction in access site vascular complications. “In the absence of randomised studies, the current study represents an important synthesis of available evidence and should inform clinical practice,” they write.

Banning and colleagues add that the findings of their analysis is consistent with another meta-analysis considering the role of ultrasound guidance for coronary angiography, which also found that the use imaging modality was associated with a reduction in bleeding events. “The adoption of ultrasound by centres in our meta-analysis was associated with almost halving of vascular and bleeding complications,” they write.

Furthermore, the authors note, the association remained significant for both major and minor access site vascular complications. “However, the association of ultrasound guidance with bleeding complications reduction was no longer statistically significant when total access site bleeding complications were separated into life-threatening and major, and minor access site complications,” Banning et al detail.

This, they write, may be partly attributed to between study heterogeneity and the insufficient power of the meta-analysis due to the low number of bleeding events.

“The lower number of events when compared with vascular complications is expected since access site bleeding is usually due to an access site vascular injury and is within rates described in contemporary literature,” the study team writes.

Considering the implications of their analysis on clinical practice, Banning et al write that their review supports the routine adoption of ultrasound to guide primary access in TAVI as a tool that can modify the risk of vascular and bleeding complications. This is particularly important in the TAVI setting, they note, as patients are elderly ad comorbid and at higher risk of sustaining access site related bleeding complications than young patient groups that undergo femoral access for coronary angiography or percutaneous coronary intervention (PCI) indications.

“Reducing access site complications should lead to reductions in the associated morbidity and mortality, and streamline discharge pathways reducing postoperative length of stay,” the study team writes. “As TAVI expands to lower risk and younger patients with severe aortic stenosis, further reducing access site complications with simple, resource neutral modifications can improve the risk-benefit and cost-effectiveness profile of TAVI”.

The authors write that the study has a number of limitations, primarily that it is an aggregate level meta-analysis based on low-moderate quality observational studies, and that the time frame of the study conduct was heterogenous, including patients recruited from 2012, which introduces temporal bias related to learning curves and advances in TAVI technology and patient care over time.

Despite this, the study team concludes that their meta-analysis reports significant association of an ultrasound-guided access approach with reductions in total vascular bleeding and access site complications by 50% and ≈40%, respectively, and has important patient-oriented ramifications for all vascular procedures requiring large-bore percutaneous access.

They conclude: “We propose a randomised trial comparing ultrasound to fluoroscopy-guided percutaneous transfemoral access in TAVI to provide high level evidence. In the interim considering the resource neutral nature of ultrasound guidance and the reducing familiarity of operators with fluoroscopy-guided femoral access, ultrasound guidance should be considered to obtain percutaneous access in TAVI.”


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