Third ventriculostomy in a single pediatric surgical unit

Purpose: Endoscopic third ventriculostomy (ETV) is a successful method of treatment for obstructive hydrocephalus that has become popular over the last 20years. The purpose of this paper is to study the outcome of infants with obstructive hydrocephalus treated by ETV by a single surgeon and to evaluate the safety, reliability, and efficacy of this treatment. Methods: All data were collected retrospectively. Between July 1999 and June 2005, 14 children underwent an ETV. In one child, a second ETV was performed. The age of the eight female and six male patients at the time of ETV ranged from less than 1month up to 13years and 11months. The indication for an ETV was an obstructive hydrocephalus. Median follow-up period was 5years and 9months. The need of a further operation after ETV was defined as a failure of ETV. Results: In six patients, the first ETV was successful. In the remaining eight patients, there was a need for further treatment (ventriculoperitoneal shunt). Although the follow-up shunt failed in one patient, he was successfully treated by a second ETV. Conclusion: Our study suggests that ETV can be successfully done in a small pediatric unit, but with a lower success rate because of small caseload, and therefore, lower experience and routine of the surgeon. Therefore, we propose a centralization of patients to obtain a higher number of cases. We confirm that ETV is a safe, reliable, and efficient method with a better outcome in children than infant

"Trooping the color”: restoring the original donor skin color by addition of melanocytes to bioengineered skin analogs

Purpose: Autologous skin substitutes to cover large skin defects are used since several years. Melanocytes, although essential for solar protection and pigmentation of skin, are not yet systematically added to such substitutes. In this experimental study, we reconstructed melanocyte-containing dermo-epidermal skin substitutes from donor skins of different skin pigmentation types and studied them in an animal model. Features pertinent to skin color were analyzed and compared in both skin substitutes and original donor skin. Methods: Keratinocytes, melanocytes, and fibroblast were isolated, cultured, and expanded from skin biopsies of light- and dark-pigmented patients. For each donor, melanocytes and keratinocytes were seeded in different ratios (1:1, 1:5, 1:10) onto collagen gels previously populated with autologous fibroblasts. Skin substitutes were then transplanted onto full-thickness wounds of immuno-incompetent rats. After 8weeks, macroscopic and microscopic analyses were conducted with regard to skin color and architecture. Results: Chromameter evaluation revealed that skin color of reconstructed light- and dark-pigmented skin was very similar to donor skin, independent of which melanocyte/keratinocyte ratio was added. Histological analyses of the skin analogs confirmed these findings. Conclusion: These data suggest that adding autologous melanocytes to bioengineered dermo-epidermal skin analogs can sustainably restore the patients' native skin colo

The silent epidemic of falls from buildings: analysis of risk factors

This study wanted to search for potential risk factors associated with falls from windows and balconies in order to eventually improve prevention. All children under the age of 16years suffering from head injuries/multiple trauma due to falls from windows or balconies treated over the last 7years at the intensive care unit (ICU) of the University Children's Hospital Zürich were analysed retrospectively (group A). Fifty patients out of all children suffering from head injuries/multiple trauma due to other types of accidents in the same period were selected at random as controls (group B). Out of a total of 241 children with head injury and/or multiple trauma, 31 (13%) fell out of a building. Twenty-seven of these victims (87%) fell from the third floor or lower. Twenty-one of the falls (68%) occurred at home. Fifteen children (49%) climbed on a piece of furniture before falling. In almost 20% of the accidents dangerous balcony or house constructions led to the fall. Parents did not witness the fall, except for three cases (10%) with direct parental involvement (one mother jumped out with her child, two mothers threw their child out of the window). Two children (6%) attempted suicide. Children aged 0-5years were predominantly represented (84%), and all six children who died were in this age group. There were significantly more patients with foreign nationalities and lower socio-professional categories in group A than in group B. In both groups, the accidents concerned the youngest child of the family in approximately 50% and happened mostly during summer evenings. There were no significant differences in injured systems and in injury severity between the two groups. This study identified young age, an immigrant family setting, low socio-professional category of the parents, dangerous house constructions, inappropriate furniture placement, and summertime evenings as risk factors for serious building falls in children. This information may foster focused preventio

Rebuild, restore, reinnervate: do human tissue engineered dermo-epidermal skin analogs attract host nerve fibers for innervation?

Purpose: Tissue engineered skin substitutes are a promising tool to cover large skin defects, but little is known about reinnervation of transplants. In this experimental study, we analyzed the ingrowth of host peripheral nerve fibers into human tissue engineered dermo-epidermal skin substitutes in a rat model. Using varying cell types in the epidermal compartment, we wanted to assess the influence of epidermal cell types on reinnervation of the substitute. Methods: We isolated keratinocytes, melanocytes, fibroblasts, and eccrine sweat gland cells from human skin biopsies. After expansion, epidermal cells were seeded on human dermal fibroblast-containing collagen type I hydrogels as follows: (1) keratinocytes only, (2) keratinocytes with melanocytes, (3) sweat gland cells. These substitutes were transplanted into full-thickness skin wounds on the back of immuno-incompetent rats and were analyzed after 3 and 8weeks. Histological sections were examined with regard to myelinated and unmyelinated nerve fiber ingrowth using markers such as PGP9.5, NF-200, and NF-145. Results: After 3weeks, the skin substitutes of all three epidermal cell variants showed no neuronal ingrowth from the host into the transplant. After 8weeks, we could detect an innervation of all three types of skin substitutes. However, the nerve fibers were restricted to the dermal compartment and we could not find any unmyelinated fibers in the epidermis. Furthermore, there was no distinct difference between the constructs resulting from the different cell types used to generate an epidermis. Conclusion: Our human tissue engineered dermo-epidermal skin substitutes demonstrate a host-derived innervation of the dermal compartment as early as 8weeks after transplantation. Thus, our substitutes apparently have the capacity to attract nerve fibers from adjacent host tissues, which also grow into grafts and thereby potentially restore skin sensitivit

Fetal surgery for myelomeningocele is effective: a critical look at the whys

Formerly, the disastrous cluster of neurologic deficits and associated neurogenic problems in patients with myelomeningocele (MMC) was generally thought to solely result from the primary malformation, i.e., failure of neurulation. Today, however, there is no doubt that a dimensional additional pathogenic mechanism exists. Most likely, it contributes much more to loss of neurologic function than non-neurulation does. Today, there is a large body of compelling experimental and clinical evidence confirming that the exposed part of the non-neurulated spinal cord is progressively destroyed during gestation, particularly so in the third trimester. These considerations gave rise to the two-hit-pathogenesis of MMC with non-neurulation being the first and consecutive in utero acquired neural tissue destruction being the second hit. This novel pathophysiologic understanding has obviously triggered the question whether the serious and irreversible functional loss caused by the second hit could not be prevented or, at least, significantly alleviated by timely protecting the exposed spinal cord segments, i.e., by early in utero repair of the MMC lesion. Based on this intriguing hypothesis and the above-mentioned data, human fetal surgery for MMC was born in the late nineties of the last century and has made its way to become a novel standard of care, particularly after the so-called "MOMS Trial”. This trial, published in the New England Journal of Medicine, has indisputably shown that overall, open prenatal repair is distinctly better than postnatal care alone. Finally, a number of important other topics deserve being mentioned, including the necessity to work on the up till now immature endoscopic fetal repair technique and the need for concentration of these extremely challenging cases to a small number of really qualified fetal surgery centers worldwide. In conclusion, despite the fact that in utero repair of MMC is not a complete cure and not free of risk for both mother and fetus, current data clearly demonstrate that open fetal-maternal surgery is to be recommended as novel standard of care when pregnancy is to be continued and when respective criteria for the intervention before birth are met. Undoubtedly, it is imperative to inform expecting mothers about the option of prenatal surgery once their fetus is diagnosed with open spina bifida

A new model for preclinical testing of dermal substitutes for human skin reconstruction

Background: Currently, acellular dermal substitutes used for skin reconstruction are usually covered with split-thickness skin grafts. The goal of this study was to develop an animal model in which such dermal substitutes can be tested under standardized conditions using a bioengineered dermo-epidermal skin graft for coverage. Methods: Bioengineered grafts consisting of collagen type I hydrogels with incorporated human fibroblasts and human keratinocytes seeded on these gels were produced. Two different dermal substitutes, namely Matriderm®, and an acellular collagen type I hydrogel, were applied onto full-thickness skin wounds created on the back of immuno-incompetent rats. As control, no dermal substitute was used. As coverage for the dermal substitutes either the bioengineered grafts were used, or, as controls, human split-thickness skin or neonatal rat epidermis were used. Grafts were excised 21days post-transplantation. Histology and immunofluorescence was performed to investigate survival, epidermis formation, and vascularization of the grafts. Results: The bioengineered grafts survived on all tested dermal substitutes. Epidermis formation and vascularization were comparable to the controls. Conclusion: We could successfully use human bioengineered grafts to test different dermal substitutes. This novel model can be used to investigate newly designed dermal substitutes in detail and in a standardized wa

Paradoxien der Geschichte. Anmerkungen zu den Fotografien von Gerhard Gäbler

PURPOSE: Surgical treatment of early-onset scoliosis (EOS) requires a balance between maintained curve correction and the capacity for spinal and thoracic growth. Spinal fusion creates irreversible conditions that prevent the implementation of further treatment methods. Our hypothesis was that non-fused anchors in growth guidance show a comparable outcome as the technique described in the literature, which involves spondylodesis of the anchoring segments. METHODS: This retrospective study analysed 148 surgeries in 22 EOS patients (11 female, 11 male) over a 15-year period. Patients underwent surgery with non-fused anchors and growth guidance techniques. Scoliosis, kyphosis, growth and anchoring segments were measured. For the latter, a new measuring technique was developed. Complications were recorded and classified. RESULTS: The mean Cobb angle reduced from 73.5 ± 24.4° to 28.4 ± 16.2° (60.2 ± 22.9%, p < 0.001) at the last follow-up. Spinal growth T1-S1 and T1-T12 were 41.1 ± 23.3 mm and 24.9 ± 16.6 mm (p < 0.001), respectively. Growth at the cranial and caudal anchoring segment was 1.5 mm/segment/year and 1.9 mm/segment/year, respectively. A total of 63 complications were documented in 20 patients, with 40 requiring unplanned revision surgery. Definitive spondylodesis was performed in three patients. CONCLUSION: Patients demonstrated a significant spinal growth including the anchoring segments. A comparable correction in Cobb angle and the type of complications was noted, although the rate of device-related complications was higher. No permanent impairment was reported. The rate of device-related complications is acceptable and outweighed by the significant degree of growth preservation and more flexible and individualised treatment strategy for patients with EOS. These slides can be retrieved under Electronic Supplementary Material

Bioengineering of Fetal Skin: Differentiation of Amniotic Fluid Stem Cells into Keratinocytes

PURPOSE Open fetal spina bifida repair has become a novel clinical standard of care. In very large spina bifida lesions, the skin defect cannot be covered primarily, asking for alternative solutions. We hypothesize that amniotic fluid stem cells (AFSC) could be differentiated into keratinocytes that could then be used to bioengineer autologous skin usable for in utero back coverage. METHODS To obtain human AFSC, amniotic fluid samples obtained from fetal surgeries were subjected to immunoselection for c-kit. C-kit-positive samples and controls were cultured with the additives morphogenetic protein 4 and vitamin C to induce differentiation towards keratinocytes. This process was monitored by measuring the expression of K8 and K14 via immunohistochemical staining, flow cytometry, and polymerase chain reaction. RESULTS After immunoselection and expansion, most cells were positive for K8, but none for K14. After completion of the differentiation protocol, cell colonies with keratinocyte-like appearance could be observed, but cells remained positive for K8 and negative for K14, indicating failed differentiation into keratinocytes. CONCLUSIONS Culturing of keratinocyte-like cells from AFSC, harvested intraoperatively, was not feasible in this setting. The reasons for failure must be investigated and eliminated, as bioengineering of fetal skin for clinical use during fetal surgery for spina bifida remains an attractive goal

Determining the origin of cells in tissue engineered skin substitutes: a pilot study employing in situ hybridization

Background: Definitive and high-quality coverage of large and, in particular, massive skin defects remains a significant challenge in burn as well as plastic and reconstructive surgery because of donor site shortage. A novel and promising approach to overcome these problems is tissue engineering of skin. Clearly, before eventual clinical application, engineered skin substitutes of human origin must be grafted and then evaluated in animal models. For the various tests to be conducted it is indispensable to be able to identify human cells as such in culture and also to distinguish between graft and recipient tissue after transplantation. Here we describe a tool to identify human cells in vitro and in vivo. Methods: In situ hybridization allows for the detection and localization of specific DNA or RNA sequences in morphologically preserved cells in culture or tissue sections, respectively. We used digoxigenin-labeled DNA probes corresponding to human-specific Alu repeats in order to identify human keratinocytes grown in culture together with rat cells, and also to label split and full thickness skin grafts of human origin after transplantation on immuno-incompetent rats. Results: Digoxigenin-labeled DNA probing resulted in an intensive nuclear staining of human cells, both in culture and after transplantation onto recipient animals, while recipient animal cells (rat cells) did not stain. Conclusion: In situ hybridization using primate-specific Alu probes reliably allows distinguishing between cells of human and non-human origin both in culture as well as in histological sections. This method is an essential tool for those preclinical experiments (performed on non-primate animals) that must be conducted before novel tissue engineered skin substitutes might be introduced into clinical practic

Human amniotic fluid derived cells can competently substitute dermal fibroblasts in a tissue-engineered dermo-epidermal skin analog

Purpose: Human amniotic fluid comprises cells with high differentiation capacity, thus representing a potential cell source for skin tissue engineering. In this experimental study, we investigated the ability of human amniotic fluid derived cells to substitute dermal fibroblasts and support epidermis formation and stratification in a humanized animal model. Methods: Dermo-epidermal skin grafts with either amniocytes or with fibroblasts in the dermis were compared in a rat model. Full-thickness skin wounds on the back of immuno-incompetent rats were covered with skin grafts with (1) amniocytes in the dermis, (2) fibroblasts in the dermis, or, (3) acellular dermis. Grafts were excised 7 and 21days post transplantation. Histology and immunofluorescence were performed to investigate epidermis formation, stratification, and expression of established skin markers. Results: The epidermis of skin grafts engineered with amniocytes showed near-normal anatomy, a continuous basal lamina, and a stratum corneum. Expression patterns for keratin 15, keratin 16, and Ki67 were similar to grafts with fibroblasts; keratin 1 expression was not yet fully established in all suprabasal cell layers, expression of keratin 19 was increased and not only restricted to the basal cell layer as seen in grafts with fibroblasts. In grafts with acellular dermis, keratinocytes did not survive. Conclusion: Dermo-epidermal skin grafts with amniocytes show near-normal physiological behavior suggesting that amniocytes substitute fibroblast function to support the essential cross-talk between mesenchyme and epithelia needed for epidermal stratification. This novel finding has considerable implications regarding tissue engineerin