Breast sensibility after mastectomy and implant-based breast reconstruction.

PURPOSE: The aim of the study is to evaluate the level of sensible impairment after mastectomy or implant-based breast reconstruction (IBBR). In addition, factors influencing breast sensibility were evaluated. METHODS: A cross-sectional study was performed in Maastricht University Medical Center between July 2016 and August 2018. Women with unilateral mastectomy with or without IBBR were included. Objective sensory measurements were performed using Semmes-Weinstein monofilaments. Their healthy breast served as control, using a paired t test. Differences between mastectomy with and without IBBR were evaluated using the independent t test. Linear regression was performed to evaluate the association between patient characteristics on breast sensibility. The paired t test was used to evaluate in which part of the breast the sensibility is best preserved. RESULTS: Fifty-one patients were eligible for inclusion. Sixteen patients underwent IBBR after mastectomy. Twenty-three patients received radiotherapy and 35 patients received chemotherapy. Monofilament values were significantly higher in the operated group compared to the reference group (p < 0.001). Linear regression showed a statistically significant association between IBBR and objectively measured impaired sensation (p = 0.008). After mastectomy, the cutaneous protective sensation is only diminished. After IBBR, it is lost in the majority of the breast. The medial part of the breast was significantly more sensitive than the lateral part in all operated breasts (p < 0.001). CONCLUSION: IBBR has a significantly negative impact on the breast sensibility compared to mastectomy alone. This study shows that the protective sensation of the skin in the breast is lost after IBBR. To our knowledge, this is the first study to evaluate the level of sensible impairment after mastectomy or IBBR. More research is necessary to confirm these results.

Sensory recovery of the breast after innervated and non-innervated autologous breast reconstructions: A systematic review.

BACKGROUND: The sensory recovery of the reconstructed breast is an undervalued topic in the field of autologous breast reconstruction. This systematic review aimed to evaluate the available literature on the sensory recovery of the breast after innervated and non-innervated autologous breast reconstructions and to assess the possible benefits of sensory nerve coaptation compared to spontaneous reinnervation of the flap. METHODS: A comprehensive literature search was conducted in PubMed, Embase and the Cochrane Library to identify all eligible studies regarding the sensory recovery of all types of innervated and non-innervated autologous breast reconstructions. RESULTS: The search yielded 334 hits, of which 32 studies concerning 1177 breast reconstructions were included. The amount of heterogeneity between the studies was high, which made the pooling of data difficult. The studies indicated that spontaneous reinnervation of autologous breast reconstructions occurred to a variable extent, depending on how and when it was measured. Despite these variable results, the sensory recovery of innervated flaps, however, was superior, started earlier and gradually improved over time with a higher chance of approaching normal values than non-innervated flaps. There is a lack of studies that assess the return of erogenous sensation and quality of life. CONCLUSION: The current evidence shows that nerve coaptation results in superior sensory recovery of the reconstructed breast compared to spontaneous reinnervation of the flap. This review illustrates that more standardised, high-quality studies with adequate sample sizes are needed to objectively evaluate the sensory recovery of the breast after autologous breast reconstructions.

Water jet indentation for local elasticity measurements of soft materials.

We present a novel elastography method for soft materials (100Pa-100kPa) based on indentation by a µm-sized water jet. We show that the jet creates a localized deformation ("cavity") of the material that can be easily visualized. We study experimentally how cavity width and depth depend on jet speed, height, incidence angle and sample elasticity. We describe how to calibrate the indenter using gels of known stiffness. We then demonstrate that the indenter yields quantitative elasticity values within 10% of those measured by shear rheometry. We corroborate our experimental findings with fluid-solid finite-element simulations that quantitatively predict the cavity profile and fluid flow lines. The water jet indenter permits in situ local stiffness measurements of 2D or 3D gels used for cell culture in physiological buffer, is able to assess stiffness heterogeneities with a lateral resolution in the range 50-500µm (at the tissue scale) and can be assembled at low cost with standard material from a biology laboratory. We therefore believe it will become a valuable method to measure the stiffness of a wide range of soft, synthetic or biological materials.

Relation between branching patterns and perfusion in stochastic generated coronary arterial trees.

Biological variation in branching patterns is likely to affect perfusion of tissue. To assess the fundamental consequences of branching characteristics, 50 stochastic asymmetrical coronary trees and one non-stochastic symmetrical branching tree were generated. In the stochastic trees, area growth, A, at branching points was varied: A = random; 1.00; 1.10; 1.13 and 1.15 and symmetry, S, was varied: S = random; 1.00; 0.70; 0.58; 0.50 and 0.48. With random S and A values, a large variation in flow and volume was found, linearly related to the number of vessels in the trees. Large A values resulted in high number of vessels and high flow and volume values, indicating vessels connected in parallel. Lowering symmetry values increased the number of vessels, however, without changing flow, indicating a dominant connection of vessels in series. Both large A and small S values gave more realistic gradual pressure drops compared to the symmetrical non-stochastic branching tree. This study showed large variations in tree realizations, which may reflect real biological variations in tree anatomies. Furthermore, perfusion of tissue clearly depends on the branching rules applied.

In situ analysis of coronary terminal arteriole diameter responses: technical report of a new experimental model.

INTRODUCTION: To date, investigation of coronary arteriole vasomotor activity has been limited to arterioles >30- 40 microm. Here, we introduce a new experimental model to allow for in situ microscopy of terminal coronary arterioles. METHODS: Rat hearts were perfused in a closed loop system (priming volume 20 ml) which was placed on a computer-controlled microscope stage. FITC-dextran and tetrodotoxin (TTX, 50 microM) were added. Tilting of the microscope by 90 degrees allowed for visual access to the ventricular surface. Arterioles were identified by the flow direction of fluorescent beads (1 microm). Images were recorded on video tape, and arteriole diameters were measured offline. Stability of the preparation and maintenance of coronary flow reserve were analyzed. Responses of coronary flow and arteriole diameters to the vasodilators papaverine and Na-nitroprusside were recorded. RESULTS: In TTX-arrested control hearts coronary flow and terminal arteriole diameters were stable for 2 h. Administration of papaverine and Na-nitroprusside increased coronary flow from 6.4 +/- 0.7 to 13.3 +/- 1.3 ml/min, decreasing coronary resistance by 52 +/- 3%. Terminal coronary arteriole diameters increased from 12.0 +/- 0.9 to 13.6 +/- 1.0 microm, decreasing hindrance of this vessel segment by 45 +/- 11%. CONCLUSION: Preservation of coronary terminal arteriolar tone and adequate responsiveness to vasodilators in the TTX-arrested isolated heart were demonstrated. Thus, this model may serve to complement our understanding of coronary microvascular control mechanisms by extending observations to the terminal arteriolar bed.