Breast Augmentation Introduction



Download 3.59 Mb.
Page3/4
Date23.04.2018
Size3.59 Mb.
1   2   3   4

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

  1. Shell configuration

  2. Filler


Shell configuration

  • All breast implants consist of a Silicone elastomer


Shell thickness

    • Thick shells are:

  1. More resistant to rupture (1st generation=3rd generation>2nd generation)

  2. More prone to contracture

  3. Less permeable


Seamed vs Seamless

  • seamless are more rupture resistant


Outer coating

Polyurethane foam (1970s -1991) – Ashley’s “Natural-Y” prosthesis.



  • Advantage:

reduce contracture (<3%) by causing an inflammatory reaction, microencapsulation of fragmented debris and surface irregularity leading to multidirectional contractile forces.

  • Complications

  1. polyurethane coating started disintegrating so that what eventually remained was a mostly smooth implant surrounded by a capsule containing foam fragments.

  2. Pain, fluid accumulation, and infection were reported.

  3. Chronic foreign body reaction

  4. Foam fragments made for difficult implant removal

  5. Allergic reactions reported.

  6. 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

  1. smaller scar

  2. 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%)

  1. 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:

  1. adjustment of the final volume

  2. patient participation in the final volume adjustment

  3. the ability to offer reinflation should saline sweat through the valve or shell occur with time

  4. treatment of rippling by overinflation

  5. in unilateral augmentation, adjustment to match contralateral ptosis by overinflation and subsequent deflation

  6. treatment of early capsular contracture by overinflation and subsequent deflation

  7. 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)

  1. patients who desire more projection in the lower pole

  2. patients who wish maximum size appearance per given volume

  3. glandular ptotic breasts

  4. constricted lower poles

  5. 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:

  1. thin patients,

  2. patients with a high inframammary crease

  3. patients with a vertically or horizontally deficient chest

  4. ptotic patients.

  • Advantage

  1. In breasts with a tight lower pole - maintain fullness in the lower pole against the constricting force of the tight skin envelope

  • Disadvantage

  1. 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

  2. malposition

    1. incidence 3-14%

    2. more likely with contracture and hematoma

    3. make sure snug implant fit into pocket

    4. reasons:

      1. some textured implants experience no anchoring fibroblastic ingrowth or collagen deposition

      2. a biofilm or meniscus likely surrounds breast implants, further discouraging fibroblastic ingrowth, and possibly acting as a lubricant;

      3. 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:


  1. lower capsule formation than gel (10-40% vs 36-88%) and contracture rates (no silicone bleeding). Lower contracture rate independent of implant placement

    1. Gylbert PRS 1990 – smooth gel vs smooth saline 50% vs 16% contracture

    2. Texturing likely to reduce contractures further

  2. easier to insert – can be deflated in situ

  3. asymmetries easier to correct

  4. medications can be added with saline

Disadvantages



  1. Deflation

    1. Average of 5 percent.

    2. Factors affecting rate:

      1. Age of implant

      2. Type of implant

      3. underfilling

      4. texturing (less deflation)

      5. capsular contracture

      6. intraluminal antibiotics/steroids/betadine

  2. Sloshing

  3. Unnatural feel – mobile, nonfixed

  4. Propensity for surface irregularities and rippling

  5. 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


    1. Bleeding (higher contracture rate)

    2. Poorer xray transmission

Cohesive gel silicone vs conventional silicone

Advantages


  1. ability to provide a natural and proportionate breast shape

  2. easier removal in the event of rupture

  3. maintains shape

  4. less likely to ripple or fold

  5. less likely to bleed

Disadvantages

  1. harder feel

  2. expensive

  3. larger incision

  4. only comes in anatomical – more obvious deformity if rotates

  5. gel fracture(? significance) – make sure incision is no smaller than 5cm



3) Hydrogel (Polyvinylpyrrolidone)

low molecular weight polymers used in hydrocolloid dressings

Brands


  1. PIP - hydroxypropyl cellulose hydrogel gel

  2. NovaGold, MistiGold - polyvinylpyrrolidone hydrogel

Developed 1994

Advantages



  1. Excreted by kidneys if leaked

  2. Provides an excellent lubrication, which in turn reduces the mechanical stress on the silicone shell = Reduced wrinkling/rupture

  3. Good xray transmission

  4. Due to the adhesive, sticky consistency of the gel filler = Natural feel

Disadvantage

  1. Implant swelling due to cosmetic gradient

    1. Misti Gold withdrawn because of this

    2. Misti Gold II has a more balanced osmotic gradient

  2. expensive

  3. insufficient safety details – not approved by FDA

  4. ?increased contracture rates – conflicting results


4) Soy Oil (Trilucent)

Advantages



  1. clearest xray transmission

Disadvantage

  1. 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.

  2. Decrease in volume over time

  3. Rupture rate 10%

  4. Lumpy capsular contracture

  5. ?carcinogenesis from breakdown products – recommended that all Trilucent implants be removed.


Incisions


  1. Transaxillary +/- endoscopic assisted

  2. Periareolar

  3. Inframammary

  4. 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



  1. 5cm(gel), 3cm(saline) incision in the axillary fold – suture anterior end of incision to prevent ripping

  2. 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)

  3. The endoscope is used to assist in the creation of the plane esp for releasing the infra mammary margin and and cauterizing the vessels

  4. Glove washed and the implant then filled with saline or gel implant is used

  5. The implant inserted

  6. Pt sat up and position checked and pocket adjusted

  7. Drain

Post op

  • Soft bra (loose)

  • 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

  • Main advantage

    1. camouflaged scar on areolar border

    2. the ability to dissect the pocket under direct visualization and the ability to adjust the IMF

    3. Ability to perform a limited skin mastopexy

    4. Reduce areolar size and glandular scoring (in tubular breasts)

  • Disadvantages include

  1. Limited exposure for dissecting the pocket

  2. Difficulty fitting implant especially if the areolar diameter is less than 3cm

  3. Risk of contamination if lactiferous ducts are transacted

  4. May interfere with nipple sensation

  5. 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

  • Pre op markings as above

  • 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

  1. the very thin patient,

  2. patients with less than 2 cm of pinch test

  3. secondary breast augmentation

  4. patients with abdominal scars or hernias.

  • Disadvantages

  1. poor access - provides the worst control for dissection of the pockets

  2. unreliable control of the inframammary fold

  3. inability to use gel-filled implants,

  4. 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


Download 3.59 Mb.

Share with your friends:
1   2   3   4




The database is protected by copyright ©ininet.org 2020
send message

    Main page