Table 1 Suggested pre-operative or perioperative flap handling or treatment conditions for the comparative short-, intermediate- or long-term whole flap or segmental gene or protein expression, cell signaling, extracellular vesicle release, neovascularization, tissue survival and other analyses within one subject

Control naïve flap (raised and placed down)

Ischemic flap (e.g., 2 h of PI)

Control naïve flap (raised and placed down)

Flap with inserted sterile silicone sheet

Control naïve flap (raised and placed down)

APF

Permanently ligated artery, vein, or both^a

RPF

Global PI (e.g., 2 h)

Global PI (e.g., 6 h)

Global PI (e.g., 2 h)

REP₁ (e.g., 4 h)

Global SI (e.g., 2 h)

Global PI (e.g., 2 h)

REP₁ (e.g., 12 h)

Global SI (e.g., 2 h)

Global PI (e.g., 4 h)

REP₁ (e.g., 12 h)

Global SI by AVO (e.g., 2 h)

Global PI (e.g., 4 h)

REP₁ (e.g., 12 h)

Global SI by AVO (e.g., 6 h)

Global PI (e.g., 2 h)

REP₁ (e.g., 6 h)

SI by AO (e.g., 2 h)

Global PI (e.g., 2 h)

REP₁ (e.g., 6 h)

SI by VO (e.g., 2 h)

Global PI (e.g., 2 h)

REP₁ (e.g., 6 h)

SI by AO (e.g., 2 h)

Global PI (e.g., 2 h)

REP₁ (e.g., 6 h)

SI by AO (e.g., 6 h)

Global PI (e.g., 2 h)

REP₁ (e.g., 6 h)

SI by VO (e.g., 1 h)

Global PI (e.g., 2 h)

REP₁ (e.g., 6 h)

SI by VO (e.g., 3 h)

Ischemic preconditioning

(e.g., 10 min × 3 times)

No ischemic preconditioning

Control naïve flap (raised and placed down)

Delayed flap (e.g., 7 days)

No delay

Implantation of control PVA sponges

Implantation of drug-preloaded PVA sponges

Saline injection

Drug injection

Intradermal delivery of non-targeting control siRNA, shRNA, or antisense oligonucleotide

Intradermal delivery of targeting siRNA, shRNA, or antisense oligonucleotide

Topical treatment with control vehicle

Topical treatment with an agent of interest

No anastomosis applied

Anastomosis