Can endovascular coil embolization of the main superficial temporal artery (STA) trunk cause scalp necrosis?

Endovascular Coil Embolization of the Main Superficial Temporal Artery and Risk of Scalp Necrosis

Yes, endovascular coil embolization of the main superficial temporal artery (STA) trunk can cause scalp necrosis, which is recognized as a major complication of head and neck tumor embolization procedures. 1

Mechanism and Risk Factors

Coil embolization of the STA trunk carries a significant risk of compromising blood supply to the scalp for several reasons:

1. Vascular Supply Disruption: The STA is a major blood supplier to the scalp, and its occlusion without adequate collateral circulation can lead to ischemia and subsequent tissue necrosis.

2. Risk Factors for Scalp Necrosis:

   • Thin scalp: Research has shown that scalp thickness is a significant predictor of wound complications after STA procedures. Every 1-mm increase in scalp thickness provides a protective effect against complications (odds ratio 0.549) 2
   • Diabetes mellitus: Increases risk of wound complications (odds ratio 4.058) 2
   • Low body mass index: Associated with higher risk of complications (odds ratio 1.21) 2
   • Inadequate collateral circulation: Particularly important in older patients or those with vascular disease

Evidence from Guidelines and Research

The Journal of Neurointerventional Surgery explicitly lists "skin and mucosal tissue necrosis" as a major complication of head and neck tumor embolization procedures 1. This complication is classified as major because it requires additional therapy, higher level of care, prolonged hospitalization, or may result in permanent sequelae.

Case reports have documented instances of skin necrosis following embolization procedures involving scalp vessels:

• A 1990 case report described skin necrosis occurring one month after embolization of a cirsoid aneurysm of the scalp using thrombogenic coils 3
• Research on cerebral revascularization using the STA found a 6.6% incidence of wound complications, with 1.5% classified as major complications including full-thickness skin necrosis 2

Alternative Approaches to Consider

When embolization of the STA is necessary, consider these approaches to minimize risk:

1. Selective Distal Embolization: Target only specific branches rather than the main trunk when possible

2. Staged Embolization: Perform the procedure in stages to allow collateral circulation to develop

3. Direct Percutaneous Approaches: For certain lesions like scalp AVMs or fistulas, direct percutaneous puncture techniques may be safer than occluding the main STA trunk 4, 5

4. Combined Techniques: Consider manual compression techniques along with embolization to achieve the desired result while preserving flow to the scalp 5

Monitoring and Management

If STA trunk embolization is unavoidable:

1. Post-procedure monitoring: Closely observe for signs of scalp ischemia including pain, pallor, and skin changes

2. Early intervention: At first signs of ischemia, consider hyperbaric oxygen therapy or other measures to improve tissue perfusion

3. Surgical management: Be prepared for possible debridement and reconstruction if necrosis occurs

Conclusion

Endovascular coil embolization of the main STA trunk carries a real risk of scalp necrosis that must be carefully considered in treatment planning. When possible, alternative approaches that preserve flow or target more distal branches should be considered to minimize this risk, particularly in patients with thin scalps, diabetes, or poor nutritional status.