Hierarchical imaging and computational analysis of three-dimensional vascular network architecture in the entire postnatal and adult mouse brain.

The formation of new blood vessels and the establishment of vascular networks are crucial during brain development, in the adult healthy brain, as well as in various diseases of the central nervous system. Here, we describe a step-by-step protocol for our recently developed method that enables hierarchical imaging and computational analysis of vascular networks in postnatal and adult mouse brains. The different stages of the procedure include resin-based vascular corrosion casting, scanning electron microscopy, synchrotron radiation and desktop microcomputed tomography imaging, and computational network analysis. Combining these methods enables detailed visualization and quantification of the 3D brain vasculature. Network features such as vascular volume fraction, branch point density, vessel diameter, length, tortuosity and directionality as well as extravascular distance can be obtained at any developmental stage from the early postnatal to the adult brain. This approach can be used to provide a detailed morphological atlas of the entire mouse brain vasculature at both the postnatal and the adult stage of development. Our protocol allows the characterization of brain vascular networks separately for capillaries and noncapillaries. The entire protocol, from mouse perfusion to vessel network analysis, takes ~10 d.

Multidisciplinary long-term care and modern surgical treatment of congenital melanocytic nevi - recommendations by the CMN surgery network.

In recent years, our knowledge of congenital melanocytic nevi (CMN) has greatly expanded. This has led to a paradigm shift. The present article represents a commentary by an interdisciplinary group of physicians from German-speaking countries with extensive experience in long-term care and surgical treatment of children and adults with CMN (CMN surgery network, "Netzwerk Nävuschirurgie", NNC). The authors address aspects such as the indication for treatment as well as treatment planning and implementation under these new premises. Adequate counseling of parents on conservative and/or surgical management requires an interdisciplinary exchange among physicians and individualized planning of the intervention, which frequently involves a multi-stage procedure. Today, the long-term aesthetic outcome is at the center of any therapeutic endeavor, whereas melanoma prevention plays only a minor role. The premise of "removal at any cost" no longer holds. Potential treatment-related adverse effects (hospitalization, wound healing disorders, and others) must be carefully weighed against the prospects of a beneficial outcome. In this context, the use of dermabrasion in particular must be critically evaluated. At a meeting of the NNC in September 2018, its members agreed on a consensus-based position on dermabrasion, stating that the procedure frequently leads to impaired wound healing and cosmetically unfavorable or hypertrophic scarring. Moreover, dermabrasion is considered to be commonly associated with considerable repigmentation that usually occurs a number of years after the procedure. In addition, the NNC members saw no benefit in terms of melanoma prevention. In the future, physicians should therefore thoroughly caution about the potential risks and often limited cosmetic benefits of dermabrasion.

Congenital hemangioma exhibiting postnatal growth.

Congenital hemangiomas are vascular tumors that are fully formed at birth, typically without postnatal growth. Noninvoluting congenital hemangiomas (NICH) have a distinctive clinical, radiologic, and histopathological profile and lack of expansion or involution over time. Herein, we describe two cases of NICH with atypical postnatal growth.

Vascular anomalies - a practical approach.

Vascular anomalies are common clinical problems (around 4.5% of all patients) in pediatric dermatology. A correct diagnosis is possible on clinical grounds in around 90% of cases; the remaining patients may require radiologic evaluations (duplex ultrasonography, MRI scan) and, rarely, histology. Vascular anomalies are divided into tumors and vascular malformations. This clear division reflects the different biological behaviors of these two groups. The infantile hemangioma represents by far the most common vascular tumor and is characterized by a typical growth cycle consisting of rapid proliferation, plateau phase, and finally slow regression. The discovery in 2008 of the efficacy of beta blockers in this disease is a therapeutic milestone. Vascular malformations can affect all types of vessels (capillaries, veins, arteries and lymphatic vessels). They usually manifest at birth and grow proportionally with the affected child. Some show marked progression especially during puberty. Considerable progress has been made with innovative interventional therapies in recent years, but surgery remains an important option. Basic knowledge of these diseases is important to every dermatologist in order to be able to counsel and manage affected patients correctly.