Robot-Assisted vs. Open Appendicovesicostomy in Pediatric Urology:A Systematic Review and Single-Center Case Series

INTRODUCTION: Appendicovesicostomy (APV) is the preferred choice of continent catheterizable channels in pediatric urology. The introduction of robot-assisted laparoscopic techniques has been correlated to superior cosmesis and convalescence and is now increasingly implemented for APV procedures. We aimed to perform a systematic review of the literature comparing open vs. robotic APV regarding possible differences in postoperative outcomes and to evaluate these findings with our own initial experiences with robotic APV compared to our previous open procedures. METHODS: We evaluated the first five patients undergoing robotic APV at our institution and compared 1-year outcomes with a consecutive series of 12 patients undergoing open APV. In a systematic literature review, we screened studies from PubMed, EMBASE, and CENTRAL comparing open and robotic APV in pediatric urology (current to December 2021) and performed meta-analyses on postoperative outcomes comparing the two groups and evaluated the grade of evidence. RESULTS: We found significantly shortened postoperative length of stay in the robotic group (p = 0.001) and comparable 1-year complication rates in robotic vs. open APV patients. We systematically screened 3,204 studies and ultimately included three non-randomized studies comparing postoperative outcomes of robotic and open APV for quantitative analysis. The open and robotic approaches performed equally well regarding overall postoperative complications, surgical reintervention, and stomal stenosis. Two of the included studies reported comparable stomal continence rates and shortened postoperative length of stay in the robotic group, in agreement with the findings in our own series. CONCLUSION: Robotic APV is equally safe to the conventional open approach with additional advantages in postoperative hospitalization length

A perioperative layered autologous tissue expansion graft for hollow organ repair

Tissue engineering has not been widely adopted in clinical settings for several reasons, including technical challenges, high costs, and regulatory complexity. Here, we introduce the Perioperative Layered Autologous Tissue Expansion graft (PLATE graft), a composite biomaterial and collagen-reinforced construct with autologous epithelium on one side and smooth muscle tissue on the other. Designed to mimic the structure and function of natural hollow organs, the PLATE graft is unique in that it can be produced in a standard operating theatre and is cost-effective. In this proof-of-principle study, we test its regenerative performance in eight different organs, present biomechanical and permeability tests, and finally explore its in vivo performance in live rabbits

Exploring the Concept of In Vivo Guided Tissue Engineering by a Single-Stage Surgical Procedure in a Rodent Model

In severe malformations with a lack of native tissues, treatment options are limited. We aimed at expanding tissue in vivo using the body as a bioreactor and developing a sustainable single-staged procedure for autologous tissue reconstruction in malformation surgery. Autologous micro-epithelium from skin was integrated with plastically compressed collagen and a degradable knitted fabric mesh. Sixty-three scaffolds were implanted in nine rats for histological and mechanical analyses, up to 4 weeks after transplantation. Tissue integration, cell expansion, proliferation, inflammation, strength, and elasticity were evaluated over time in vivo and validated in vitro in a bladder wound healing model. After 5 days in vivo, we observed keratinocyte proliferation on top of the transplant, remodeling of the collagen, and neovascularization within the transplant. At 4 weeks, all transplants were fully integrated with the surrounding tissue. Tensile strength and elasticity were retained during the whole study period. In the in vitro models, a multilayered epithelium covered the defect after 4 weeks. Autologous micro-epithelial transplants allowed for cell expansion and reorganization in vivo without conventional pre-operative in vitro cell propagation. The method was easy to perform and did not require handling outside the operating theater

Decellularization of the Murine Cardiopulmonary Complex

We present here a decellularization protocol for mouse heart and lungs. It produces structural ECM scaffolds that can be used to analyze ECM topology and composition. It is based on a microsurgical procedure designed to catheterize the trachea and aorta of a euthanized mouse to perfuse the heart and lungs with decellularizing agents. The decellularized cardiopulmonary complex can subsequently be immunostained to reveal the location of structural ECM proteins. The whole procedure can be completed in 4 days.The ECM scaffolds resulting from this protocol are free of dimensional distortions. The absence of cells enables structural examination of ECM structures down to submicron resolution in 3D. This protocol can be applied to healthy and diseased tissue from mice as young as 4-weeks old, including mouse models of fibrosis and cancer, opening the way to determine ECM remodeling associated with cardiopulmonary disease

Insights into cellular behavior and micromolecular communication in urothelial micrografts

Abstract Autologous micrografting is a technique currently applied within skin wound healing, however, the potential use for surgical correction of other organs with epithelial lining, including the urinary bladder, remains largely unexplored. Currently, little is known about the micrograft expansion potential and the micromolecular events that occur in micrografted urothelial cells. In this study, we aimed to evaluate the proliferative potential of different porcine urothelial micrograft sizes in vitro, and, furthermore, to explore how urothelial micrografts communicate and which microcellular events are triggered. We demonstrated that increased tissue fragmentation subsequently potentiated the yield of proliferative cells and the cellular expansion potential, which confirms, that the micrografting principles of skin epithelium also apply to uroepithelium. Furthermore, we targeted the expression of the extracellular signal-regulated kinase (ERK) pathway and demonstrated that ERK activation occurred predominately at the micrograft borders and that ERK inhibition led to decreased urothelial migration and proliferation. Finally, we successfully isolated extracellular vesicles from the micrograft culture medium and evaluated their contents and relevance within various enriched biological processes. Our findings substantiate the potential of applying urothelial micrografting in future tissue-engineering models for reconstructive urological surgery, and, furthermore, highlights certain mechanisms as potential targets for future wound healing treatments

Decellularization and antibody staining of mouse tissues to map native extracellular matrix structures in 3D

The extracellular matrix (ECM) is a major regulator of homeostasis and disease, yet the 3D structure of the ECM remains poorly understood because of limitations in ECM visualization. We recently developed an ECM-specialized method termed in situ decellularization of tissues (ISDoT) to isolate native 3D ECM scaffolds from whole organs in which ECM structure and composition are preserved. Here, we present detailed surgical instructions to facilitate decellularization of 33 different mouse tissues and details of validated antibodies that enable the visualization of 35 mouse ECM proteins. Through mapping of these ECM proteins, the structure of the ECM can be determined and tissue structures visualized in detail. In this study, perfusion decellularization is presented for bones, skeletal muscle, tongue, salivary glands, stomach, duodenum, jejunum/ileum, large intestines, mesentery, liver, gallbladder, pancreas, trachea, bronchi, lungs, kidneys, urinary bladder, ovaries, uterine horn, cervix, adrenal gland, heart, arteries, veins, capillaries, lymph nodes, spleen, peripheral nerves, eye, outer ear, mammary glands, skin, and subcutaneous tissue. Decellularization, immunostaining, and imaging take 4-5 d

Modeling Metastatic Colonization in a Decellularized Organ Scaffold-Based Perfusion Bioreactor

Metastatic cancer spread is responsible for most cancer-related deaths. To colonize a new organ, invading cells adapt to, and remodel, the local extracellular matrix (ECM), a network of proteins and proteoglycans underpinning all tissues, and a critical regulator of homeostasis and disease. However, there is a major lack in tools to study cancer cell behavior within native 3D ECM. Here, an in-house designed bioreactor, where mouse organ ECM scaffolds are perfused and populated with cells that are challenged to colonize it, is presented. Using a specialized bioreactor chamber, it is possible to monitor cell behavior microscopically (e.g., proliferation, migration) within the organ scaffold. Cancer cells in this system recapitulate cell signaling observed in vivo and remodel complex native ECM. Moreover, the bioreactors are compatible with co-culturing cell types of different genetic origin comprising the normal and tumor microenvironment. This degree of experimental flexibility in an organ-specific and 3D context, opens new possibilities to study cell–cell and cell–ECM interplay and to model diseases in a controllable organ-specific system ex vivo