Chemical angioplasty vs. balloon plus chemical angioplasty for delayed cerebral ischemia: a pilot study of PbtO₂ outcomes

Delayed cerebral ischaemia (DCI) is a major cause of morbidity and mortality after aneurysmal subarachnoid haemorrhage (aSAH). Chemical angioplasty (CA) and transluminal balloon angioplasty (TBA) are used to treat patients with refractory vasospasm causing DCI. Multi-modal monitoring including brain tissue oxygenation (PbtO₂) is routinely used at this centre for early detection and management of DCI following aSAH. In this single-centre pilot study, we are comparing these two treatment modalities and their effects on PbtO₂.

Retrospective case series of patients with DCI who had PbtO₂ monitoring as part of their multimodality monitoring and underwent either CA or TBA combined with CA. PbtO₂ values were recorded from intra-parenchymal Raumedic NEUROVENT-PTO® probes. Data were continuously collected and downloaded as second-by-second data. Comparisons were made between pre-angioplasty PbtO₂ and post-angioplasty PbtO₂ median values (4 h before angioplasty, 4 h after and 12 h after).

There were immediate significant improvements in PbtO₂ at the start of intervention in both groups. PbtO₂ then increased by 13 mmHg in the CA group and 15 mmHg in the TBA plus CA group in the first 4 h post-intervention. This improvement in PbtO₂ was sustained for the TBA plus CA group but not the CA group.

Combined balloon plus chemical angioplasty results in more sustained improvement in brain tissue oxygenation compared with chemical angioplasty alone. Our findings suggest that PbtO₂ is a useful tool for monitoring the response to angioplasty in vasospasm.