Implant-Based Breast Reconstruction after Mastectomy, from the Subpectoral to the Prepectoral Approach: An Evidence-Based Change of Mind?

Over the last years, prepectoral implant-based breast reconstruction has undergone a renaissance due to several technical advancements regarding mastectomy techniques and surgical approaches for the placement and soft tissue coverage of silicone implants. Initially abandoned due to the high incidence of complications, such as capsular contraction, implant extrusion, and poor aesthetic outcome, the effective prevention of these types of complications led to the prepectoral technique coming back in style for the ease of implant placement and the conservation of the pectoralis muscle function. Additional advantages such as a decrease of postoperative pain, animation deformity, and operative time contribute to the steady gain in popularity. This review aims to summarize the factors influencing the trend towards prepectoral implant-based breast reconstruction and to discuss the challenges and prospects related to this operative approach

Qu’attendons-nous ?

Le médecin de la civilisation déchiffre dans l’attente le symptôme d’une volonté malade (idéalisme, nihi­lisme), qui renonce à l’affirmation présente pour le néant de l’avenir, l’au-delà transcendant. Mais guérir, dans l’immanence du devenir, n’est pas se délivrer de l’attente, c’est la transformer en une pratique déses­pérée : pour Nietzsche, écrire.Waiting for something that never occurs, the beyond, the transcendent, may be considered, from a medical point of view, as a symptom of sickness (idealism or nihilism). But the cure, in the immanence of beco­ming, does not mean to get rid of waiting, it means to turn it into a desperate practice, such as writing

La vérité de l’apparence : de l’optique à la psychologie

Lambert développe une conception originale de l’apparence, qui se distingue de la conception classique (Descartes) par le fait que la logique de l’apparence n’est pas déduite de la logique de la vérité, mais est restituée dans son ordre propre : la phénoménologie n’est pas l’alethiologie. L’apparence n’est pas illusion – sur ce point Lambert s’accorde avec les philosophes – mais elle n’est pas non plus réductible à l’ordre du savoir, bien que la connaissance de l’apparence soit une condition de la connaissance elle-même. Pour dégager le langage de l’apparence, et comprendre sa sémiologie, Lambert médite sur l’optique, qui permet de définir un sujet qui ne soit ni pure subjectivité ni constitutif de l’objectivité.Lambert develops an original conception of appearance, distinct from the classical concept to the extent that the logic of appearance is not inferred from the logic of truth, but is rendered in its proper order : phenomenology is not alethiology. Appearance is not illusion—in this respect Lambert agrees with philosophers—but it cannot be reduced to the order of knowledge, although knowledge of appearance is a condition of knowledge itself. In order to disentangle language from appearance and understand its semiology, Lambert reflects on optics, so as to define a subject who is neither pure subjectivity neither constitutive of objectivity

Gender-specific ischemic tissue tolerance in critically perfused skin

Purpose: The purpose of this study is to determine gender-specific differences in the development of necrosis in persistent ischemic tissue and to analyze whether differences are due to gender-specific loss of vascular reactivity or change in ischemic tolerance. Methods: Hairless mice (skh-1) of both genders were assigned to three groups of adolescent, adult, and senescent age. Critical ischemia was induced by transection of the two distal pedicles of the animal's ear. Microcirculation was assessed over a 5-day period using intravital epifluorescence microscopy. Tissue necrosis, blood flow, functional capillary density (FCD), red blood cell (RBC) velocity, and capillary diameter were analyzed. Results: Induction of persistent ischemia caused an age-dependent demarcation of nonperfused flap tissue. Adult and senescent females developed markedly more necrosis than age-matched males (49 ± 1% vs. 37 ± 3% and 53 ± 3% vs. 44 ± 2%, respectively; p < 0.05), whereas no gender-specific difference in flap necrosis was observed in adolescent animals (31 ± 2% vs. 33 ± 3%). Gender did not affect the amount of microcirculatory dysfunction in the flap. Thus, age-matched females and males exhibited a comparable decrease of FCD, RBC velocity, and capillary dilatory response. Conclusions: Both age and female gender may predispose for an increased susceptibility to develop ischemic tissue necrosis. The increased necrosis in female animals does not apply to an aggravated microvascular dysfunction, but rather to a reduced ischemic tissue toleranc

Microvascular Fragments Protect Ischemic Musculocutaneous Flap Tissue from Necrosis by Improving Nutritive Tissue Perfusion and Suppressing Apoptosis

Microvascular fragments (MVF) derived from enzymatically digested adipose tissue are functional vessel segments that have been shown to increase the survival rate of surgical flaps. However, the underlying mechanisms have not been clarified so far. To achieve this, we raised random-pattern musculocutaneous flaps on the back of wild-type mice and mounted them into dorsal skinfold chambers. The flaps were injected with MVF that were freshly isolated from green fluorescent protein-positive (GFP+ ) donor mice or saline solution (control). On days 1, 3, 5, 7, and 10 after surgery, intravital fluorescence microscopy was performed for the quantitative assessment of angiogenesis, nutritive blood perfusion, and flap necrosis. Subsequently, the flaps were analyzed by histology and immunohistochemistry. The injection of MVF reduced necrosis of the ischemic flap tissue by ~20%. When compared to controls, MVF-injected flaps also displayed a significantly higher functional capillary density and number of newly formed microvessels in the transition zone, where vital tissue bordered on necrotic tissue. Immunohistochemical analyses revealed a markedly lower number of cleaved caspase-3+ apoptotic cells in the transition zone of MVF-injected flaps and a significantly increased number of CD31+ microvessels in both the flaps’ base and transition zone. Up to ~10% of these microvessels were GFP+ , proving their origin from injected MVF. These findings demonstrate that MVF reduce flap necrosis by increasing angiogenesis, improving nutritive tissue perfusion, and suppressing apoptosis. Hence, the injection of MVF may represent a promising strategy to reduce ischemia-induced flap necrosis in future clinical practice

Bromelain Protects Critically Perfused Musculocutaneous Flap Tissue from Necrosis

Bromelain has previously been shown to prevent ischemia-induced necrosis in different types of tissues. In the present study, we, therefore, evaluated for the first time, the tissue-protective effects of bromelain in musculocutaneous flaps in mice. Adult C57BL/6N mice were randomly assigned to a bromelain treatment group and a control group. The animals were treated daily with intraperitoneal injections of 20 mg/kg bromelain or saline (control), starting 1 h before the flap elevation throughout a 10-day observation period. The random-pattern musculocutaneous flaps were raised on the backs of the animals and mounted into a dorsal skinfold chamber. Angiogenesis, nutritive blood perfusion and flap necrosis were quantitatively analyzed by means of repeated intravital fluorescence microscopy over 10 days after surgery. After the last microscopy, the flaps were harvested for additional histological and immunohistochemical analyses. Bromelain reduced necrosis of the critically perfused flap tissue by ~25%. The bromelain-treated flaps also exhibited a significantly higher functional microvessel density and an elevated formation of newly devel oped microvessels in the transition zone between the vital and necrotic tissues when compared to the controls. Immunohistochemical analyses demonstrated a markedly lower invasion of the myeloperoxidase-positive neutrophilic granulocytes and a significantly reduced number of cleaved caspase 3-positive apoptotic cells in the transition zone of bromelain-treated musculocutaneous flaps. These findings indicate that bromelain prevents flap necrosis by maintaining nutritive tissue perfusion and by suppressing ischemia-induced inflammation and apoptosis. Hence, bromelain may represent a promising compound to prevent ischemia-induced flap necrosis in clinical practice

Selective blockade of endothelin-B receptor improves survival of critically perfused musculocutaneous flaps

Background and aims: Insufficient perfusion of distal flap areas, which may lead to partial necrosis, still represents a challenge in reconstructive surgery. In the process of microvascular and endothelial dysfunction, endothelins (ETs) and their receptors may play an important role. Therefore, the aim of the study was to investigate in a chronic in vivo model the effect of various ET-receptor antagonists in critically perfused flap tissue. Materials and methods: A random pattern musculocutaneous flap was elevated in the back of 25 C57BL/6 mice and fixed into a dorsal skinfold chamber. Repetitive intravital fluorescence microscopy was performed over a 10-day observation period, assessing arteriolar diameter, arteriolar blood flow (aBF), functional capillary density (FCD), the area of tissue necrosis, and the development of newly formed blood vessels. ET-receptor blockers were administrated intraperitoneally 30min before induction of ischemia, as well as daily during the subsequent 4-day period, including (1) BQ-123, a specific ET-A-receptor antagonist (ET-A = 1mg/kg), (2) BQ-788, a selective ET-B-receptor antagonist (ET-B = 1mg/kg), and (3) PD-142893, a nonselective ET-AB-receptor antagonist (ET-AB = 0.5mg/kg). Animals receiving saline only served as controls (n = 7). Results: Despite an increase in aBF during the 10-day observation period (day 1 = 1.92 ± 0.29nl/s; day 10 = 4.70 ± 1.64nl/s), the flaps of saline-treated controls showed a distinct decrease in FCD (94 ± 12cm/cm2). This perfusion failure resulted in flap necrosis of 52 ± 3%. Selective blockade of the ET-B receptor caused a further increase in aBF already at day 1 (2.97 ± 0.42nl/s), which persisted during the following 10-day observation period (day 10 = 5.74 ± 0.69nl/s). Accordingly, adequate FCD could be maintained (day 10 = 215 ± 8cm/cm2; p < 0.05 vs control), resulting in a significant reduction in flap necrosis (day 10 = 25 ± 4%; p < 0,05). In contrast, neither selective blockade of the ET-A receptor nor nonselective ET-A- and ET-B-receptor blockade were able to significantly affect aBF when compared to controls (day 1 = ET-A = 1.39 ± 0.10nl/s; ET-AB = 1.53 ± 0.80nl/s; n.s.). Accordingly, flap necrosis after ET-A- and ET-AB-receptor inhibition did not differ from that of controls (day 10 = ET-A: 46 ± 10%; ET-AB = 51 ± 7%). Conclusion: Our data show that only selective ET-B-receptor inhibition is capable of maintaining nutritive perfusion and, hence, reducing necrosis in critically perfused flap tissue. Accordingly, administration of ET-B-receptor antagonists may be considered in the treatment of critically perfused flap

Improved Vascularization and Survival of White Compared to Brown Adipose Tissue Grafts in the Dorsal Skinfold Chamber

Fat grafting is a frequently applied procedure in plastic surgery for volume reconstruction. Moreover, the transplantation of white adipose tissue (WAT) and brown adipose tissue (BAT) in creasingly gains interest in preclinical research for the treatment of obesity-related metabolic defects. Therefore, we herein directly compared the vascularization capacity and survival of WAT and BAT grafts. For this purpose, size-matched grafts isolated from the inguinal WAT pad and the interscapu lar BAT depot of C57BL/6N donor mice were syngeneically transplanted into the dorsal skinfold chamber of recipient animals. The vascularization and survival of the grafts were analyzed by means of intravital fluorescence microscopy, histology, and immunohistochemistry over an observation period of 14 days. WAT grafts showed an identical microvascular architecture and functional mi crovessel density as native WAT. In contrast, BAT grafts developed an erratic microvasculature with a significantly lower functional microvessel density when compared to native BAT. Accordingly, they also contained a markedly lower number of CD31-positive microvessels, which was associated with a massive loss of perilipin-positive adipocytes. These findings indicate that in contrast to WAT grafts, BAT grafts exhibit an impaired vascularization capacity and survival, which may be due to their higher metabolic demand. Hence, future studies should focus on the establishment of strategies to improve the engraftment of transplanted BAT