The Central Mound Pedicle: A Safe and Effective Technique for Reduction Mammaplasty.

BACKGROUND: The central mound technique offers a relatively less common approach for breast reduction. This study evaluated the expected safety and efficacy outcomes using this technique in a large patient series. METHODS: A retrospective review of all patients undergoing central mound breast reduction at the authors' institution between June of 1999 and November of 2018 was performed. Both bilateral macromastia and unilateral symmetrizing reduction patients were included but evaluated separately for some outcomes. Patient demographics and comorbidities, operative details, postoperative adverse events, and BREAST-Q scores were recorded. Associations between preoperative variables and outcomes were assessed with chi-square tests, Wilcoxon tests, and Kendall tau-b correlations. RESULTS: A total of 325 patients were identified for inclusion (227 bilateral and 98 unilateral; 552 breasts). The average patient age was 46 years, and the average body mass index was 27.4 kg/m. Among the bilateral macromastia patients, the average operative time was 3 hours 34 minutes, and average breast tissue removed was 533 g (right breast) and 560 g (left breast). Among all patients, average follow-up was 169 days. On a per-breast basis for all patients, the following complication rates were observed: seroma, 0.2 percent; hematoma, 1.1 percent; dehiscence, 2.9 percent; infection, 1.5 percent; hypertrophic scar, 4.6 percent; nipple necrosis, 0.4 percent; fat necrosis, 0.9 percent; and skin flap necrosis, 1.7 percent. Using the BREAST-Q Reduction/Mastopexy questions on a Likert scale ranging from 1 to 5, restricted to the bilateral macromastia patient population, all scores improved with statistical significance. CONCLUSION: The central mound pedicle is a safe and effective approach for reduction mammaplasty for both bilateral macromastia patients and unilateral symmetrizing operations. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Creep compliance rheology with a probe-like cylindrical geometry.

BACKGROUND: Rheology experiments have been performed on the vitreous humor, a soft gel that rests inside of the eye, to study its viscoelastic behavior and underlying macromolecular structure. A significant challenge for experimentalists is preserving the macromolecular structure when removing vitreous from in vivo conditions. OBJECTIVE: We have developed a novel probe-like rheometer geometry that allows us to perform shear rheology experiments on the vitreous humor in situ. The aim of this study is to assess the feasibility of the probe geometry. METHODS: Creep compliance responses of silicone oils, Xanthan gum solutions, and bovine and porcine vitreous humor were measured using the probe geometry and compared to measurements performed with standard geometries. RESULTS: Viscosities calculated from the creep responses of silicone oils closely match between the probe and standard geometry. Viscosities and creep compliance values of Xanthan gum measurements achieve order of magnitude agreement between the probe and standard geometry. Significant differences are detected with the probe between bovine and porcine vitreous (p<0.001). CONCLUSIONS: These results suggest the probe may feasibly measure viscosities of Newtonian fluids, and correctly detect differences in the creep response of complex fluids with varying viscoelastic behaviors.