title: Breast augmentation with extra-projected and high-cohesive Dual-Gel Prosthesis 510: a prospective study of 75 consecutive cases for a new method (the Zenith system).
abstract: BACKGROUND
  Extra-projected Natrelle 510 belongs to a new generation of silicone breast implants. A single-surgeon prospective study set out to investigate the device's features, outcomes, and complications, and devise a proper measurement method based on the zenith system.
  
  
  METHODS
  From December 2004 to June 2010, 75 subjects (150 implants) were enrolled in four cohorts: primary augmentation (66.7%), primary mastopexy augmentation (17.3%), secondary implant exchange (9.3%), and secondary implant exchange+pexy (6.7%). The system used to select the implant correlated the point of maximal projection (vertex-zenith) and nipple position. The surgical approach included (1) narrow pocket, preferably dual-plane; (2) device vertex 1-2.5 cm beneath nipple (zenith range=12°-23°) related to a nipple-inframammary fold distance of 7-7.5 cm at maximal stretch and a nipple-sternum/lower-pole line distance of 4-5 cm; (3) inframammary fold lowered minimally; (4) vertex at ±1 cm from the midbreast meridian crossing the nipple; and (5) maximizing the biomechanical effects between soft-tissue dynamics, firmer gel pressure, and pectoralis major counterpressure to expand the lower skin (dynamic tension).
  
  
  RESULTS
  Mean follow-up was 26.5 months (range=6-72); in 20 subjects; follow-up was over 3 years (average=50 months) with a 90.8% patient satisfaction rate. This rate was lower in patients with preoperative ptosis. There was inframammary preservation with 60% of the implants and modification in 40% (0.80±0.45 cm). The overall complication rate per implant was 16.6% and included wound healing/scarring (7%), malrotation (2.6%, only 1% after primary augmentation), rippling (2%), capsular contracture (1.3%), and bottoming-out (0.6%). The revision rate was 6%, of which 3.3% were pocket revisions. Greater skills are required through the learning curve, patient education, case selection, planning using the nipple-vertex relationship (the zenith system), and improved surgical manipulation. Indications and contraindications were analyzed. Cosmetic results were compliant with different breast shapes, and excellent for the breast with poor projection, in thin subjects, and those with low BMI. Ptotic breast should require a larger amount of pexy, 510 did not lift the breast enough.
  
  
  CONCLUSIONS
  Based on vertex-nipple distance, dynamic tension, and skin extensibility, this new approach gives guidelines and methods to perform breast augmentation with extra-projected implants.
  
  
  METHODS
  This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors at www.springer.com/00266.
authors.affiliation: Plastic and Reconstructive Surgery Unit, Fondazione IRCCS Istituto Nazionale Tumori, Via Venezian 1, 20133, Milano, Italy. egidio.riggio@istitutotumori.mi.it
authors.forename: Egidio
authors.initials: E
authors.lastname: Riggio
mesh_terms: D000328:Adult; D001941:Breast Diseases / Q000453:epidemiology / Q000601:surgery*; D019928:Breast Implantation / Q000009:adverse effects / Q000379:methods* / Q000706:statistics & numerical data*; D018427:Breast Implants / Q000009:adverse effects / Q000706:statistics & numerical data*; D015331:Cohort Studies; D004954:Esthetics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007558:Italy; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000706:statistics & numerical data; D017060:Patient Satisfaction / Q000706:statistics & numerical data*; D011183:Postoperative Complications / Q000453:epidemiology; D011446:Prospective Studies; D011474:Prosthesis Design; D020034:Silicone Gels; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D020034:Silicone Gels