The investigation of the relation between expansion strategy and outcomes of two-stage expander-implant breast reconstruction.

BACKGROUND: Numerous risk factors for the complications of two-stage, immediate implant-based breast reconstruction have been identified, although few studies have directly examined the impact of breast size and expansion protocols on the surgical outcomes of breast reconstruction. This study aimed to evaluate the impact of breast size, expansion velocity, and volume-related variables on postoperative complications of breast reconstruction. METHODS: The cohort involved patients who underwent immediate breast expander reconstruction at a single center between 2017 and 2019. The breast size was classified into three categories according to the weight of the mastectomy specimen as small (<300 g), medium (≥300 g, ≤500 g), or large (>500 g). Multifactorial logistic regressions were used to assess the impact of variables, and receiver operating characteristic (ROC) curve analysis was used to determine the optimal cut-off value for predicting the complication event. RESULTS: Of the 174 breasts (168 patients), 51 (29.3%), 66 (37.9%), and 57 (32.6%) breasts were classified as small, medium, and large, respectively. The rate of infection (P=0.014) and expander/implant failure (P=0.007) significantly differed according to breast size, with the rate being the highest in large breasts. Multivariate logistic regression analysis showed that body mass index (BMI) [odds ratio (OR): 1.25; P=0.003], nipple-sparing mastectomy (OR: 2.82; P=0.036), sentinel biopsy (OR: 5.10; P=0.016), final expansion volume (OR: 0.99; P=0.022), and expansion velocity (OR: 0.703; P=0.024) were significant independent predictors of any complication. In the ROC analysis, breast weight >696 g could predict the possibility of revision surgery, with a sensitivity of 42.9% and specificity of 81.8%. CONCLUSIONS: The final expansion volume and expansion velocity have a significant negative relationship with overall complications in breast reconstruction. A standard expansion protocol needs to be established to ensure the success of two-stage breast reconstruction.

Effect of Morphologically Transformed Acellular Dermal Matrix on Chronic Diabetic Wounds: An Experimental Study in a Calvarial Bone Exposure Diabetic Rat Model.

BACKGROUND: The use of acellular dermal matrix on chronic diabetic wounds in clinical practice is hindered by its high cost and difficulty in application. We aimed to acquire experimental evidence on the effect of morphologically transformed acellular dermal matrix on chronic diabetic wounds and investigate how this transformation affects the wound healing mechanism. MATERIALS AND METHODS: We developed a new chronic wound model that resembles a diabetic chronic wound as it involves an open wound with partial calvarial bone exposure in diabetic rats. According to treatment materials, rats were assigned into the CONTROL, ADM, and PASTE groups. The wound healing period was subdivided into T1 and T2 (postoperative days 14 and 30, respectively). Three-staged analyses were performed using 3D camera, histological analysis, and real-time quantitative polymerase chain reaction. RESULTS: The morphologically transformed acellular dermal matrix showed a compatible treatment rate in the total wound and more rapidly reduced the initial bone exposure area. In the PASTE group, collagen scaffold appeared at a later period and expression levels of epidermal growth factor and epidermal growth factor receptor increased. CONCLUSIONS: The transformation of acellular dermal matrix into the pulverized form is thought to contribute to its non-inferior therapeutic effect compared with normal acellular dermal matrix. With respect to the mechanism, the pulverized form reduced the bone exposure area in the early stage and provided a collagen scaffold at a later period. An increase in epithelial growth factors through mechanochemical transformations along with increased contact area contribute to the enhanced healing capacity of the morphologically transformed acellular dermal matrix.

What is the impact of infrapopliteal endovascular intervention on free flap survival in diabetic foot reconstruction?

BACKGROUND: The combination of endovascular intervention and microvascular free flap transfer has been effectively used for chronic ischemic wounds of lower limb. The aim of this study was to determine the influence of angioplasty on free flap survival in diabetic foot ulcer reconstruction. METHODS: A retrospective research was conducted for 46 diabetic patients with chronic ulcer of the foot. All patients underwent free flap reconstruction because of their non-healing wound with tendon or bone exposure. Patient's demography, clinical data related to vascular status, vascular intervention, and free flap transfer procedure were collected. Flap survival rate was compared between the group with severe arterial stenosis group and non-severe stenosis group. It was also compared among groups with different revascularization results. RESULTS: The average age of patients was 56.2 ± 10.8 years. There were 14 (30.4%) men and 32 (69.6%) women. Of 46 patients, 23 (50%) had severe infrapopliteal arterial stenosis. All 23 patients underwent endovascular intervention. Their final results of the pedal arch were type 1 in 13 patients, type 2A in 7 patients, type 2B in 2 patients, and type 3 in 1 patient. Total flap necrosis was found in 5 (10.9%) cases, marginal necrosis in 4 (8.7%) cases, and wound dehiscence in 4 (8.7%) cases. There was no significant difference in flap loss between severe arterial stenosis patients and non-severe arterial stenosis patients. In the severe arterial stenosis group, after endovascular intervention, patients with type 1 of pedal arch had a significantly lower rate of total flap necrosis than others. There was no association between the use of revascularized recipient artery and flap survival. CONCLUSIONS: Our study revealed that the quality of pedal arch was crucial for free flap survival. Thus, PTA should aim to re-establish a complete pedal arch to increase wound healing rate and flap success.

The Effects of Subcutaneously Injected Novel Biphasic Cross-Linked Hyaluronic Acid Filler: In Vivo Study.

BACKGROUND: Biphasic hyaluronic acid (HA) fillers have been used extensively to improve facial skin. However, in some cases, the skin surface is irregular because of the premature loss of HA solution. We propose a new biphasic filler (G-filler) to overcome this problem by using small particles of HA hydrogel instead of HA solution, which can provide a smooth skin surface and good durability. METHOD: We evaluated the rheologic properties of G-filler and its physiologic effects after subcutaneous injection in a mouse model by histologic analysis. RESULTS: The G-filler showed a similar elastic modulus (G') and complex viscosity (η*) as the conventional biphasic filler, but had a higher viscous modulus (G″) than the conventional monophasic filler. The highest material elasticity (tan δ) value and the lowest percentage elasticity value indicate the rheologic properties of G-filler are closer to those of liquids. After subcutaneous injection of G-filler, collagen content (~ 2-fold) and elastin fibers (~ 6.5-fold) were significantly increased at 12 weeks compared to those of the saline group. Fibronectin (~ 2.6-fold) and the laminin-immunolabeled cell number (~ 6-fold) were also significantly increased at 12 weeks. Significant increases in the CD31-immunoreactive cell numbers of the G-filler groups were observed at 2, 6, and 12 weeks (~ 3.7-fold) compared to those of the saline groups. There were no significant differences between the G-filler and saline groups in patterns of skin thickness and inflammatory cell numbers around loading sites. CONCLUSION: These findings demonstrate that the injection of a new biphasic filler with improved rheologic properties can effectively stimulate extracellular matrix production and angiogenesis without safety concerns. NO LEVEL ASSIGNED: 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 - www.springer.com/00266 .

Measurement of spatial pulse wave velocity by using a clip-type pulsimeter equipped with a Hall sensor and photoplethysmography.

A prototype of a clip-type pulsimeter equipped with a magnetic field-sensing semiconductor Hall sensor was developed. It has a permanent magnet attached in the "Chwan" position to the center of a radial artery. The clip-type pulsimeter is composed of a hardware system measuring voltage signals. To measure spatial pulse wave velocity (SPWV), the signal from the radial artery pulsimeter and that from the photoplethysmography (PPG) were simultaneously compared. The pulse wave data from a clinical test of 39 clinical participants (male:female = 25:14) with a mean age of 24.36 (±2.35) years was analyzed. The mean SPWV, which was simultaneously measured from the radial artery pulsimeter and PPG, was 0.8 m/s. We suggest the SPWV results were higher for men than women, because of the better vascularity of terminal tissue in men. The findings of this research may be useful for developing a biomedical signal storage device for a U-health-care system.

Measurement of blood pressure using an arterial pulsimeter equipped with a Hall device.

To measure precise blood pressure (BP) and pulse rate without using a cuff, we have developed an arterial pulsimeter consisting of a small, portable apparatus incorporating a Hall device. Regression analysis of the pulse wave measured during testing of the arterial pulsimeter was conducted using two equations of the BP algorithm. The estimated values of BP obtained by the cuffless arterial pulsimeter over 5 s were compared with values obtained using electronic or liquid mercury BP meters. The standard deviation between the estimated values and the measured values for systolic and diastolic BP were 8.3 and 4.9, respectively, which are close to the range of values of the BP International Standard. Detailed analysis of the pulse wave measured by the cuffless radial artery pulsimeter by detecting changes in the magnetic field can be used to develop a new diagnostic algorithm for BP, which can be applied to new medical apparatus such as the radial artery pulsimeter.