BRA SIZE
Girth measured under the arms and breast/chest girth measured over the nipple
Increase 1 inch Acup
increase 2 inch B cup
increase 3 inch C cup
increase 4 inch D cup
consider 1 cup size to be about 150 mls or cc, if an implant is under the muscle you need to allow about 75-100 cc more.
Deciding Size
Measure the base width of the breast mound as a linear measurement from the visible medial border of the breast mound to the visible lateral border of the breast mound in front view.
Nipple-to-inframammary fold distance (N:IMFMaxSt), measured under maximal stretch
For optimal long-term coverage, the base width of the implant selected should not exceed the base width of the patient's existing parenchyma, except in cases of tubular breasts, severely constricted lower pole breasts, or breasts with a base width less than 10.5 cm
IMF distance to nipple should be at least 7cm depending on implant size chosen
Deciding on Implant Type
History
1st generation (Dow Corning 1974-1978)
thick silicone rubber elastomer shell with seams and smooth surface
high-molecular-weight “gum” filled with amorphous silica
Rupture rates were low because of the tough shell,
complications from high capsular contracture rates and gel-filled seepage was probably considerable.
2nd generation (1979- 1987)
Smooth surface thin shells
Less viscous gels
Higher rupture and bleed rates
3rd generation (1980s)
increasing the thickness of the outer envelope
adding an inner barrier layer to limit silicone gel diffusion
using a thicker silicone gel material which is less likely to migrate into surrounding tissues should rupture occur.
Life expectancy not known
Implants can be considered with regards to
Shell configuration
Filler
Shell configuration
All breast implants consist of a Silicone elastomer
Shell thickness
More resistant to rupture (1st generation=3rd generation>2nd generation)
More prone to contracture
Less permeable
Seamed vs Seamless
seamless are more rupture resistant
Outer coating
Polyurethane foam (1970s -1991) – Ashley’s “Natural-Y” prosthesis.
reduce contracture (<3%) by causing an inflammatory reaction, microencapsulation of fragmented debris and surface irregularity leading to multidirectional contractile forces.
polyurethane coating started disintegrating so that what eventually remained was a mostly smooth implant surrounded by a capsule containing foam fragments.
Pain, fluid accumulation, and infection were reported.
Chronic foreign body reaction
Foam fragments made for difficult implant removal
Allergic reactions reported.
FDA reported in 1992 that breakdown foam (toluene diamine) products from in vivo hydrolysis may be carcinogenic - estimated lifetime cancer risk to a human from release of TDA from the cover of a breast implant is 41 per million per implant
Inner coating
Third generation shells have a barrier layer on the interior surface.
McGhan’s Intrashiel – diphenyl barrier layer sandwiched between 2 silicone layers.
Dow Corning Silastic II – fluorosilicone.
Reduces bleeding by 90%
Advantage said to cause less silicone bleeding
Surface texturing
The reduced contracture rates of polyurethane foam was thought be to due in part to the texturing
Microtexturing the surface of an implant by ion-etching was found to modify the response of the surrounding soft tissues to the implant and retard the development of an organized, tight collagen capsule.
Picha confirmed that the collagen in the capsules around rough-textured implants was less organized and less dense than that of smooth surfaced implants.
From animal studies, a pore size of 350 μm was required to disrupt the formation of a continuous capsule aligned parallel to the implant surface
Probability of contracture increases with time but the textured implants have the ability to retard capsular development
The benefit of texturing may be lost if implant placed subpectoral
Collis and Coleman PRS 2000
Summary of studies (textured vs smooth)
Silicone filled
Ohlsén 1992 – 0% vs 44% at 1 year
Malata, Coleman BJPS 1997,2000 – 11% vs 59% at 3 years and 11% vs 65% at 10 years
Pollock 1993 – 4% vs 21%
Asplund PRS 1996 – 3-9% vs 10-20% at 1 year, submuscular
Hakelius PRS 1997
25 women, 1 breast smooth and the other textured placed in subglandular position
4% vs 68% at 5 years
Saline filled
Burkhardt PRS 1994 - 2 vs 40%
Burkhardt PRS 1995 – 12% vs 22% (lower after Betadine irrigation)
Tarpila PRS 1997 – 39% vs 38% at 1 year, one type on each side
Inflatable (saline)
Introduced by Arion in 1965.
Benefits
smaller scar
easier to achieve symmetry
Initial models unreliable
Faulty valve and fold-flaw cracking - defect always in the border between the patch containing the filling valve and the prosthesis envelope itself.
Most recommend overfilling by 5% to 15%
Underfilling risks: palpable shell folding, visible rippling, sloshing and rupture
Incidence of deflation 0.5-16% (Mentor 1600 ~4%)
Risks factors:
Early – device failure (20% for Heyer Shulte model 1800), damage during surgery
Late - underfilling the implant by more than 25 mL, intraluminal antibiotics, and intraluminal steroids.
Double lumen
attempt at combining the benefits of saline and gel
initial design – saline outside ( steroid, antibiotic), gel inside.
Becker implant – saline inside and gel outside
Capsular contracture rate – 5%
Most removed ports within 6 months – some keep it long term
Benefits:
adjustment of the final volume
patient participation in the final volume adjustment
the ability to offer reinflation should saline sweat through the valve or shell occur with time
treatment of rippling by overinflation
in unilateral augmentation, adjustment to match contralateral ptosis by overinflation and subsequent deflation
treatment of early capsular contracture by overinflation and subsequent deflation
mammographic examination of breast tissue is possible by deflating the implant
Disadvantages of the technique include the financial cost of the prosthesis, palpable axillary ports, and displacement or flipping
Anatomical
Saline and gel forms
tapered upper pole and fuller lower pole are designed to match the ideal breast shape, with the more fixed shape designed to prevent upper pole collapse under gravity ie gravitational forces dictate fluids conform to a teardrop shape.
given the same fill volume, an anatomic implant with its narrower base will produce greater projection (24.4%) and greater height (19.6%) than a round implant.
Indications (Tebbetts)
patients who desire more projection in the lower pole
patients who wish maximum size appearance per given volume
glandular ptotic breasts
constricted lower poles
breasts with highly mobile parenchyma likely to slide off the anterior surface of a round implant and produce the “double bubble” deformity
Round implants less appropriate for:
thin patients,
patients with a high inframammary crease
patients with a vertically or horizontally deficient chest
ptotic patients.
In breasts with a tight lower pole - maintain fullness in the lower pole against the constricting force of the tight skin envelope
patients with wide chest girths - narrower base diameter of the anatomic implant will not be sufficient to reach the anterior axillary line, and in this instance a round implant, having a wider base and more volume, may be more esthetic and achieve the same degree of projection
malposition
incidence 3-14%
more likely with contracture and hematoma
make sure snug implant fit into pocket
reasons:
some textured implants experience no anchoring fibroblastic ingrowth or collagen deposition
a biofilm or meniscus likely surrounds breast implants, further discouraging fibroblastic ingrowth, and possibly acting as a lubricant;
the forces exerted on a retromuscular implant by the pectoralis major (even more so if the muscle is partially released) are directed in a horizontal and oblique vector (i.e., clavicle and midsternal origin to humeral greater tubercle insertion).
Filler
1) Saline
Advantages:
lower capsule formation than gel (10-40% vs 36-88%) and contracture rates (no silicone bleeding). Lower contracture rate independent of implant placement
Gylbert PRS 1990 – smooth gel vs smooth saline 50% vs 16% contracture
Texturing likely to reduce contractures further
easier to insert – can be deflated in situ
asymmetries easier to correct
medications can be added with saline
Disadvantages
Deflation
Average of 5 percent.
Factors affecting rate:
Age of implant
Type of implant
underfilling
texturing (less deflation)
capsular contracture
intraluminal antibiotics/steroids/betadine
Sloshing
Unnatural feel – mobile, nonfixed
Propensity for surface irregularities and rippling
Less suitable in subglandular position
2) Silicone
Silicone is the generic name for a family of silicon-carbon–based polymers.
regarded as one of the most compatible materials available for implanting into the human body
The polymer chains vary in length: the longer the chain, the greater the viscosity of the silicone.
Advantages
a. Natural feel and look
Disadvantages
Bleeding (higher contracture rate)
Poorer xray transmission
Cohesive gel silicone vs conventional silicone
Advantages
ability to provide a natural and proportionate breast shape
easier removal in the event of rupture
maintains shape
less likely to ripple or fold
less likely to bleed
Disadvantages
harder feel
expensive
larger incision
only comes in anatomical – more obvious deformity if rotates
gel fracture(? significance) – make sure incision is no smaller than 5cm
3) Hydrogel (Polyvinylpyrrolidone)
low molecular weight polymers used in hydrocolloid dressings
Brands
PIP - hydroxypropyl cellulose hydrogel gel
NovaGold, MistiGold - polyvinylpyrrolidone hydrogel
Developed 1994
Advantages
Excreted by kidneys if leaked
Provides an excellent lubrication, which in turn reduces the mechanical stress on the silicone shell = Reduced wrinkling/rupture
Good xray transmission
Due to the adhesive, sticky consistency of the gel filler = Natural feel
Disadvantage
Implant swelling due to cosmetic gradient
Misti Gold withdrawn because of this
Misti Gold II has a more balanced osmotic gradient
expensive
insufficient safety details – not approved by FDA
?increased contracture rates – conflicting results
4) Soy Oil (Trilucent)
Advantages
clearest xray transmission
Disadvantage
Prone to seepage. The adverse reactions consisted of oxidation of the oil, foul smell, inflammation and swelling, both of which subsided when the implant was removed. Even though the removal of the implants alleviated the swelling and/or inflammation, and there was no evidence that they caused long-term health problems, the implants were withdrawn in 1999.
Decrease in volume over time
Rupture rate 10%
Lumpy capsular contracture
?carcinogenesis from breakdown products – recommended that all Trilucent implants be removed.
Incisions
Transaxillary +/- endoscopic assisted
Periareolar
Inframammary
Transumbilical
Transaxillary augmentation
Hoehler 1973 – blunt blind subglandular dissection using urethral sound
Ideal for those with small breast volume in a high position on the chest
Can also be placed subfascial and retropectoral
Endoscope assisted popularized by Tebbets
Early concerns over limited visibility for dissection, implant malposition, and insecure hemostasis have faded with mounting experience.
Use of endoscope has facilitated release of the inferior musculofascial attachments
Advantage of this technique is that the scar is small and not noticeable and no incision on the areolar, breast skin or parenchyma
Disadvantage
limited exposure
Subglandular placement if done blindly may be associated with higher bleeding risk
Axillary banding – fibrous banding across the axillary scar
Scar visible if wearing sleeveless shirts
Increased risk of infection and seroma
Medial arm (intercostal brachial) numbness – usually transient
Subclavian vein thrombosis reported
Implant tends to ride higher
Unable to address tubular breast or constricted lower pole
Fails to correct ptotic breast
Can address pseudoptosis and grade I but is difficult and there are concerns about over and underdissection
Limited to round implants although in PRS Aug 2005, anatomical silicone implants were placed subfascially via endoscope
Technique
Preop
Stand patient, the IMF, midline and the new imf marked(which is usually 1cm below the existing but varies based on the diameter of the new implant
Operation
Infiltration- care taken to stay parallel to the chest wall
5cm(gel), 3cm(saline) incision in the axillary fold – suture anterior end of incision to prevent ripping
dissection is directed medially to the lat aspect of the pec major muscle. Then the plane between the pec major and minor is created with blunt dissection - some use urethral sound)
The endoscope is used to assist in the creation of the plane esp for releasing the infra mammary margin and and cauterizing the vessels
Glove washed and the implant then filled with saline or gel implant is used
The implant inserted
Pt sat up and position checked and pocket adjusted
Drain
Post op
No under wire (or tight bra) as it redirects the implant into a superior position
Oral abs
R/v at 24 hrs then week to assess for hematomas
Only those with smooth implants are instructed to massage the breasts
They are advised to massage in a medial superior and inferior direction but never in a lateral direction
by the second week the pt should be able to make the breasts touch one another to maintain the large pockets and should be sleeping on her stomach to help maintain the large pocket
Periareolar incision
camouflaged scar on areolar border
the ability to dissect the pocket under direct visualization and the ability to adjust the IMF
Ability to perform a limited skin mastopexy
Reduce areolar size and glandular scoring (in tubular breasts)
Limited exposure for dissecting the pocket
Difficulty fitting implant especially if the areolar diameter is less than 3cm
Risk of contamination if lactiferous ducts are transacted
May interfere with nipple sensation
Scarring may be visible on breast mound - beware areolas that are lightly colored with indistinct margins
Best used in pts with indistinct IMF and those with large areolars that is not deeply pigmented
Pitanguy uses a transareolar incision which leaves a better scar but transects ducts
Technique
A half moon incision made in the areolar side of the areolar skin junction
Direct incision through breast tissue or subcutaneously down to IMF.
If the subpectoral implant used the inferior aspect of the pec major is incised and the pocket created
Closed in layers
Inframammary incision
Described by Cronin and Gerow
Most direct route - Allows complete visualization of either the pre- or subpectoral plane, does not violate breast parenchyma but often leaves an unsightly scar.
The incision should be placed at or just above the projected new inframammary fold
Should measure 3cm for saline and 5cm for gel implants
May be difficult in those with significant hypoplasia that causes an ill-defined inframammary fold or with a constricted breast and a breast fold too close to the areola
Transumbilical
Described by Johnson 1993
Subglandular placement, saline implants only
Subpectoral possible but very difficult
contraindications
the very thin patient,
patients with less than 2 cm of pinch test
secondary breast augmentation
patients with abdominal scars or hernias.
poor access - provides the worst control for dissection of the pockets
unreliable control of the inframammary fold
inability to use gel-filled implants,
the need for a second incision at the time of revision.
Implant removal
Removal without replacements show poor results
Dermoparenchymal mastopexy generally recommended
Deepithelialized TRAM flap described
Complications
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