Avoiding complications with fillers

Costas Papageorgiou MD, London  January 2014

Over the last decade the use of dermal fillers has revolutionized the way we treat the aging face, with their market expanding at an exponential rate. As with any medical intervention, complications can occur and adverse effects are not rare. State regulations vary greatly with regard to who can inject fillers and experience and knowledge can greatly affect the results.

Complications following facial injections have recently heightened awareness of the possibility of iatrogenic embolism and tissue necrosis.

Soft tissue necrosis is a devastating and unpredictable complication following dermal filler injections. Multiple mechanisms to explain this complication have been proposed, including vascular compression, vessel damage, and intraarterial filler emboli. A recent study though has  elucidated that the main mechanism of filler-induced tissue necrosis is capillary perfusion block.

Embolization requires the coexistence of 3 factors: a sufficient amount of material delivered into the vessel with blockage a monte, a high injection pressure, and retrograde flow. Therefore a high injection pressure should be avoided by adjusting the size of the needle and the syringe. The plunger of a large syringe has a greater cross-sectional area and should theoretically allow lower pressure injections (Pascal’s law). However, the control over the volume is severely impaired.

Contrary the use of a small-gauge needle does not seem to prevent retrograde flow as initiation of an injection requires more pressure to overcome resistance resulting in higher initial pressures transmitted to the tissues.

Although no rule can completely prevent the occurrence of such a devastating complication, some reasonable precautions may decrease the risk of during facial cosmetic injections:

1. Blunt, flexible microcannulas should be preferred as they allow facial injection with a limited number of insertion points, thus reducing the risk of arterial entry.
2. Aspiration before injection
3. Injections should be performed slowly and with the least amount of pressure possible.
4. Incremental injections should be fractionated to minimize the chance of depositing a critical amount of material into an artery. Avoiding bolus injection is critical.
5. Small needles should be preferred to larger ones. Although their initial pressure is higher smaller needles slow injection speed.
6. Repeated treatments with smaller volumes may be preferred to single-stage high-volume injections.
7. Application of a vasocontrictor can reduce the lumen of the arteries.
8. Pay particular attention to surgically pre-treated areas.
9. Have access to hyaluronidase when you use hyaluronic acid fillers.

In summary even among skilled injectors,  serious effects may develop,  but simple steps can minimize risks. It is of outmost importance that patients are educated on the treatment and the risks associated.

As physicians it is important to understand the anatomic vascular perplexity of the face, etiopathogenesis of vascular occlusion and adopt techniques to safeguard against this severe complication.