Implants Flashcards
What are some indications to get implants?
- cosmetic augmentation
- post-mastectomy reconstruction
- congenital amastia
- severe hypoplasia/asymmetry
- inlays for tissue defects
Why would a patient have a tissue defect?
lumpectomy can leave uneven areas etc
What locations can implants be placed in?
- subglandular (cosmetic)
- submuscular (reconstruction)
- subcutaneous
- intramammary
What is a TRAM flap?
- transverse rectus abdominis muscle
- part of abdominal wall, fat, muscle and vasculature is transplanted to the breast
What is a latissimus dorsi flap?
tissue from the upper back is transplanted to the breast, implant goes under muscle
What are the two common types of implants?
silicone and saline
What is the most common implant used?
single lumen saline
What are the two types of silicone implants?
- single lumen (gummy bear)
- double lumen: outer saline, inner silicone or outer silicone, inner saline
What is a dangerous and illegal method of breast augmentation?
silicone injections
What is the sonographic appearance of implants?
- defined shell/tissue surface
- smooth elliptical shape
- anechoic lumen (silicone has echoes at higher gain)
- anterior reverb
- possible folds
What is the difference between saline and silicone implants and the size they appear on US?
saline appears on US as its actual size
silicone appears larger in AP
What do the shell walls look like on US?
two thin echogenic parallel lines, a third line can be seen above and is the fibrous capsule
What does an expander valve look like on US?
- usually on anterior surface
- usually subareolar
Why can wrinkling of the skin occur with implants?
- can be secondary to implant contracture
- placement within a small pocket or underfilled implant
- due to lobulation of implant shell
What kind of implants are more prone to wrinkling?
saline
What is a peripheral fold?
AKA radial fold
- normal
- extends from inner wall for variable distance
- internal, long, wavy complex folds
What can a peripheral fold appear as?
implant rupture
What is reverberation artifact? What does it cause difficulties with?
- repeating bands of echoes along anterior surface
- can make it harder to detect intracapsular rupture
What kind of implants are more likely to cause reverberation artifact?
silicone
What kind of implants cause propagation speed artifact and why?
silicone, speed of sound is slower than in soft tissue and causes posterior structures to appear deeper
What are short term complications of implants?
- pain, tenderness
- hematoma
- infection and abscess
- seroma
- loss of nipple sensation
What are long term implant complications?
- capsular fibrosis and calcification
- capsular contracture
- herniation
- migration
- chronic infection
- rupture
- silicone granuloma
- autoimmune response
What is capsular fibrosis?
- thin rim of scar tissue around implant’s outer shell
- begins within weeks of implantation
- response to a foreign object in body
What is the MC implant complication?
fibrous encapsulation
What is capsular contracture?
- hardening & distortion of implant
- tightening & constriction of the fibrous capsule
What measurement of the fibrous capsule indicates capsular contracture?
Over 1.5 mm thick
What does capsular contracture do to implants?
causes them to become more rounded or balloon shaped, causes asymmetry/distortion
What kind of implants more commonly cause capsular contracture?
- subglandular silicone
- thin, smooth implant shells
What are some things that can help prevent capsular contracture?
texturing, coating, subpectoral location
How can capsular calcification affect US?
Can cause attenuation that limits evaluation
What is herniation of an implant?
- break in fibrous capsule that allows portion of intact implant to bulge through
- can be palpable
Why are US and MRI better at detecting herniation than mammogram?
Mammo cannot differentiate between herniation & extracapsular rupture
What is the second MC implant complication?
rupture
What are the two types of rupture?
intracapsular and extracapsular
What are risk factors for rupture?
trauma and implant age
What is the difference between a saline and silicone rupture?
- silicone can cause inflammatory response and form granulomas
- saline is absorbed by the tissues
What is intracapsular silicone implant rupture?
- silicone leaks outside of implant through shell defect
- still inside fibrous capsule
What does intracapsular implant rupture look like on US?
significant collapse and folding of implant (stepladder sign)
What is the stepladder sign?
- parallel line sign
- most reliable
- parallel echogenic bands reflecting from folded layers of collapsed implant shell
What is an extracapsular silicone implant rupture?
- silicone gel leaks through a defect in shell and fibrous capsule
- silicone migrates into breast tissue, chest wall and distant locations
What is the snowstorm sign?
- most reliable finding for extracapsular rupture
- affected tissues are highly echogenic with dirty shadowing
- irregular pattern due to difference in acoustic properties of tissue and silicone
What is another finding that may be present with an extracapsular rupture?
- fluid collection
- hypo/anechoic, outside fibrous capsule
- less reliable
