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Fat grafting, fillers, botulinum toxin and peels

Aesthetic injections look simple but carry serious risks: filler entering a vessel can cause necrosis or blindness and is treated at once with hyaluronidase, gluteal fat grafting is permitted only under the skin and not into muscle, and botulinum toxin diffusing to the eyelid causes temporary ptosis.

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Why it matters in the exam

Fat grafting (Coleman technique): low-pressure harvest, processing (centrifugation or filtration) and injection in small aliquots through many tunnels, because each particle needs contact with bleeding tissue. Part of the fat is resorbed, so slight overcorrection and sometimes several rounds are planned. Complications: oil cysts, fat necrosis and calcifications — in the breast they appear on mammography but are distinguished from cancer by appropriate work-up — infection, and fat embolism. In gluteal fat augmentation, injection into the gluteal muscle caused deaths from fat embolism through the gluteal veins, so the recommendation is subcutaneous injection only. Fillers: hyaluronic acid (reversible with hyaluronidase), calcium hydroxylapatite, poly-L-lactic acid (stimulates collagen) and permanent materials. The "Tyndall effect" — a blue hue from superficial hyaluronic acid injection.

Vascular occlusion by filler presents with sudden blanching, pain and then purple mottling; high-risk areas: the glabella, the nose and the nasolabial fold. Treatment: stop injecting, high-dose repeated hyaluronidase, warmth and massage; falling vision is an immediate ophthalmic emergency. Botulinum toxin type A blocks acetylcholine release at the neuromuscular junction (cleaving SNAP-25); the effect starts after 2 to 3 days, peaks at about two weeks and lasts 3 to 4 months. Eyelid ptosis from botulinum toxin is treated with apraclonidine drops (which contract Müller's muscle), and brow ptosis is caused by injecting too low on the forehead. Contraindications: pregnancy, myasthenia gravis, Lambert-Eaton and aminoglycoside use. Chemical peels: superficial (glycolic acid, low-concentration TCA), medium (TCA 35% with Jessner) and deep (phenol — may cause arrhythmias, so cardiac monitoring and fluids). Before medium or deep peels and laser, herpes prophylaxis is given; topical retinoid before treatment speeds healing; and isotretinoin in recent months delays healing and requires postponement.

Key points

• Vascular occlusion — high-dose hyaluronidase.
• Gluteal fat — subcutaneous only.
• Botulinum: onset 2 to 3 days, peak about two weeks, 3 to 4 months.
• Eyelid ptosis — apraclonidine.
• Phenol — cardiac monitoring; herpes — prophylaxis.

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Sources

• ASERF and multi-society task force on gluteal fat grafting safety, 2018 and 2022 — Subcutaneous-only injection
• Global aesthetic consensus on the prevention and management of hyaluronic acid filler vascular occlusion, 2020 — Hyaluronidase protocol
• US FDA prescribing information for onabotulinumtoxinA (cosmetic), current — Mechanism, onset, duration and adverse effects

Sources are given for further reading; the text is written afresh and not copied from them.

Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.