Increased coiling rate suggests shift towards endovascular techniques during COVID-19 pandemic

Thanh Nguyen (L), Raul Nogueira

A global study published in the Journal of Neurology, Neurosurgery and Psychiatry (JNNP) has revealed that, while ruptured aneurysm clipping rates remained largely unchanged, there was an increased rate of ruptured aneurysm coiling between 2019 and 2021—which the authors believe indicates a shift towards endovascular techniques during the first year of the COVID-19 pandemic.

In their JNNP report, Thanh Nguyen (Boston University School of Medicine, Boston, USA), Raul Nogueira (University of Pittsburgh Medical Center, Pittsburgh, USA) and colleagues also note that, over the same period, there was a decrease in aneurysmal subarachnoid haemorrhage (aSAH) admissions volume, driven by a decrease in mild-to-moderate aSAH presentations. However, they observed no significant difference in aSAH in-hospital mortality between the pandemic and pre-pandemic years—except within a subgroup analysis of higher aSAH mortality in hospitals with the highest COVID-19 burden—attesting to “resilience in the care of patients with aSAH amidst the pandemic”.

Given the widespread impact of COVID-19 across global healthcare systems, as well as the fact prior studies indicated a decrease in the incidences of aSAH during the early stages of the pandemic, Nguyen, Nogueira and colleagues set out to evaluate differences in the incidence and severity of aSAH presentation, and ruptured aneurysm treatment modality, during the first year of the COVID-19 pandemic (1 January 2020 to 28 February 2021) compared with the preceding year (1 January 2019 to 29 February 2020).

To this end, they conducted a cross-sectional, retrospective study including 49 countries and 187 centres, with primary objectives being to evaluate changes in the volume of non-traumatic SAH, aSAH hospitalisations and aSAH in-hospital mortality, and secondary objectives being to evaluate the severity of aSAH admission presentation, the modality treatment of aSAH, and the associations between COVID-19 admission volumes and aSAH volumes, over the same period. The researchers adjusted the start date of the pandemic by country, based on the date of the first reported COVID-19 case.

“Our primary hypothesis was that, similar to the first wave, there would be a decrease in SAH and aSAH hospitalisations between the first year of the COVID-19 pandemic and the preceding year,” Nguyen, Nogueira and colleagues write in JNNP. “Our secondary hypothesis was that there could be a shift toward increased use of ruptured aneurysm coiling, as we had observed in the first wave of the pandemic.”

Across the total study period (1 January 2019 to 31 May 2021), there were 20,680 non-traumatic SAH admissions and 344,491 COVID-19 admissions among participating centres, the authors detail. Of these, there were 16,247 aSAH admissions, and 8,300 endovascular coiling procedures and 4,240 aneurysmal clipping procedures over the study period.

Reporting the results of their study, Nguyen, Nogueira and colleagues note observed declines in aSAH admissions (–6.4%, p=0.0001) during the first year of the pandemic compared with the prior year—with this being most pronounced in high-volume SAH and high-volume COVID-19 hospitals. There was a trend towards a decline in mild (−5%, p=0.06) and moderate (−8.3%, p=0.06) presentations of SAH too, but no difference in higher SAH severity.

According to the researchers, ruptured aneurysm clipping rates remained unchanged before and during the first year of the pandemic (30.7% vs 31.2%, p=0.58), whereas ruptured aneurysm coiling increased (53.97% vs 56.5%, p=0.009). There was no difference in aSAH in-hospital mortality rates between these two time periods (19.1% vs 20.1%, p=0.12), the researchers add.

Nguyen, Nogueira and colleagues conclude by stating that there was a decline in non-traumatic SAH and aSAH admissions during the first year of the COVID-19 pandemic—and this decline was “likely driven by an observed trend in the decline of patients presenting with mild-to-moderate aSAH”, and is concordant with decreases seen in other urgent cases, such as ischaemic stroke.

In addition, Nguyen spoke to NeuroNews to highlight “another important data element” from this JNNP study: the fact it reports current rates (19–20%) of in-hospital aSAH mortality between 2019 and 2020 from a swath of global centres.


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