A 15-year-old girl having Tetralogy of Fallot underwent cardiac catheterization for coil embolization of indirect aortopulmonary collaterals detected on cardiac computed tomography scan prior to the intra-cardiac repair surgery.

Selective right subclavian angiography using a 5F internal mammary artery (IMA) diagnostic catheter demonstrated a severe focal proximal-segment narrowing suggestive of critical stenosis (Figure 1A). The lesion appeared concentric and flow-limiting. The patient remained asymptomatic during the procedure. After intra-arterial vasodilator administration, there was no dynamic change in lesion seen.

Given the absence of clinical findings and the patient’s young age, repeat angiography was performed after catheter repositioning and exchange. The previously observed stenosis completely resolved, revealing a normal-caliber subclavian artery without residual narrowing (Figure 1B).

Figure 1: (A) Right subclavian artery angiography using a 5F IMA catheter showing severe focal mid-segment narrowing mimicking critical stenosis (arrow).

(B) Repeat angiography after catheter repositioning demonstrating complete resolution of the lesion, consistent with catheter-induced

vasospasm.

Catheter-induced vasospasm especially ostial in location is a well-recognized phenomenon during angiographic procedures and results from mechanical irritation of the arterial wall, leading to transient vascular smooth muscle contraction [1]. In our case, pseudo stenosis in the proximal part of the subclavian artery was seen that is unusual and rare. In large peripheral arteries such as the subclavian artery, this may occur due to catheter tip contact, vessel straightening, or transient wall apposition (“wall-tucking”), particularly with relatively stiff or selectively shaped catheters such as the internal mammary artery catheter. The angiographic appearance may closely mimic fixed obstructive disease, especially when the spasm is focal, flow-limiting and sub ostial in location. Pediatric and adolescent patients, particularly those with congenital heart disease, may exhibit enhanced vascular reactivity and endothelial dysfunction, predisposing them to exaggerated vasospastic responses even in the absence of traditional atherosclerotic risk factors [2-3]. Procedural factors such as catheter size, manipulation, and repeated contrast injections may further amplify this response.

In the present case, the absence of clinical features of subclavian artery disease, including lack of inter-arm blood pressure difference or pulse deficit, combined with the complete resolution of the lesion on repeat angiography without vasodilator administration, strongly supports an iatrogenic and reversible mechanism. Recognition of this phenomenon is essential, as failure to identify catheter-induced spasm may lead to unnecessary interventions. Careful reassessment, catheter repositioning, or repeat imaging should be routinely considered when angiographic findings are discordant with the clinical context.

Written consent taken from the patient.

Disclosures

No use of artificial intelligence (AI) in the production of submitted work.

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2. Ho HH, Jafary FH, Ong PJ. Radial artery spasm during transradial cardiac catheterization and percutaneous coronary intervention: incidence, predisposing factors, prevention, and management. Cardiovascular Revascularization Medicine. 2012; 13: 193-195.
3. Zus AS, Crisan S, Luca S, Nisulescu D, Valcovici M, Patru O, et al. Radial artery spasm-a review on incidence, prevention and Diagnostics. 2024; 14: 1897.