Intraoperative laser angiography using the SPY system: review of the literature and recommendations for use

Table 6 Variables that may impact use of modalities to evaluate tissue perfusion

Characteristics associated with ischemia	Previous radiation treatment
	Previous or aggressive surgery*
	Current smoking
	Obesity
	Diabetes
	Vasculopathy
	Chronic corticosteroid use
	Thin mastectomy flaps
Agents that interfere with imaging techniques	Methylene blue
Agents that interfere with imaging techniques	Lymphazurin blue
Agents that affect blood flow	Vasoconstrictors (eg, epinephrine)**

*Previous incisions may affect blood flow; ICG perfusion assessment may be of particular utility for detection of perfusion across scars.
**Vasopressors affect all methods of estimation of perfusion in tissue. Diminished blood flow following administration of epinephrine may indicate the need to wait ≥2 hours for accurate ICG imaging. A negative result on ICG perfusion assessment may indicate the need to wait longer for recovery of perfusion.

ISSN: 1750-1164