Tissue Bridge Research Articles

Free Flap Outcomes of Microvascular Reconstruction after Repeated Segmental Mandibulectomy in Head and Neck Cancer Patients

This is the first study to investigate the impact of a second fibula flap or a soft tissue flap combined with bridging plate for a repeated segmental mandibulectomy reconstruction on flap outcomes in head and neck cancer patients. A retrospective comparative analysis (2007–2016) of 61 patients who underwent a second segmental mandibulectomy was performed. 20 patients underwent a fibula flap reconstruction whereas 41 had a soft tissue flap and plate reconstruction. No significant difference was seen in the operative time, total hospital stay, flap loss, re-exploration rates, plate exposure rate, or recipient site infection rate. On multivariate analysis, patients reconstructed with a soft tissue flap and bridging plate (odds ratio (OR) 3.997; 95% confidence interval (CI), 1.046–15.280, p = 0.043) and complications developed in previous surgery (OR 4.792; 95% CI, 1.120–20.493, p = 0.035) were shown to be independent predictors of a prolonged nasogastric tube dependence. The utilization of a soft tissue flap with plate is associated with comparative results of acute complication rate within 1 week, recipient site infection rate, and plate exposure rate to free fibula flaps alone. Free fibula flaps may result in a decreased risk for prolonged tube dependence compared to free soft tissue flap reconstructions.

Accessory polar renal artery not pre-operatively visualized at extra-peritoneal para-aortic lymphadenectomy

The objective of this video is to describe the technique of extra-peritoneal para-aortic laparoscopic lymphadenectomy and emphasize potential vascular risks that should be taken into account during the procedure.The procedure...

Width and neurophysiologic properties of tissue bridges predict recovery after cervical injury.

ObjectiveTo assess whether preserved dorsal and ventral midsagittal tissue bridges after traumatic cervical spinal cord injury (SCI) encode tract-specific electrophysiologic properties and are predictive of appropriate recovery.MethodsIn this longitudinal study, we retrospectively assessed MRI scans at 1 month after SCI that provided data on width and location (dorsal vs ventral) of midsagittal tissue bridges in 28 tetraplegic patients. Regression analysis assessed associations between midsagittal tissue bridges and motor- and sensory-specific electrophysiologic recordings and appropriate outcome measures at 12 months after SCI.ResultsGreater width of dorsal midsagittal tissue bridges at 1 month after SCI identified patients who were classified as being sensory incomplete at 12 months after SCI (p = 0.025), had shorter sensory evoked potential (SEP) latencies (r = −0.57, p = 0.016), and had greater SEP amplitudes (r = 0.61, p = 0.001). Greater width of dorsal tissue bridges predicted better light-touch score at 12 months (r = 0.40, p = 0.045) independently of baseline clinical score and ventral tissue bridges. Greater width of ventral midsagittal tissue bridges at 1 month identified patients who were classified as being motor incomplete at 12 months (p = 0.002), revealed shorter motor evoked potential (MEP) latencies (r = −0.54, p = 0.044), and had greater ratios of MEP amplitude to compound muscle action potential amplitude (r = 0.56, p = 0.005). Greater width of ventral tissue bridges predicted better lower extremity motor scores at 12 months (r = 0.41, p = 0.035) independently of baseline clinical score and dorsal tissue bridges.ConclusionMidsagittal tissue bridges, detectable early after SCI, underwrite tract-specific electrophysiologic communication and are predictors of appropriate sensorimotor recovery. Neuroimaging biomarkers of midsagittal tissue bridges may be integrated into the diagnostic workup, prediction of recovery, and patients' stratification in clinical trials.

Autologous transobturator midurethral sling.

The aim of this study is to describe a novel transobturator midurethral sling surgery technique by using rectus abdominis fascia. A 54-year-old woman complaining of urinary leakage during effort was diagnosed as pure stress urinary incontinence after detailed questioning, pelvic examination, uroflowmetry and measurement of residual urine volume. She was anxious about complications related to synthetic meshes. However, she was not interested in relatively morbid surgeries such as colposuspension and pubovaginal sling. Autologous transobturator midurethral sling was discussed with the patient. The patient approved the surgery and the surgery was planned. A 5 cm rectus fascia was harvested via suprapubic incision and non-absorbable stay sutures were placed on its' both edges. Anterior vaginal incision together with paravaginal dissection was performed, as in classical transobturator sling surgery. Groin puncture and blind dissection of adipose tissue was performed. C-shaped trocars were inserted, and advanced through groin punctures and brought up to midurethral incision by finger guidance. Stay sutures were transported via C-shaped trocars to the groin puncture in both sides. Graft was positioned on the midurethral part without any tension and stay sutures were tied to create a tissue bridge on obturator membrane. Incisions were closed and vaginal tampon was placed. Patient was discharged at the first postoperative day. At postoperative third and sixth months, patient was totally dry and did not have any voiding complaints. Small abdominal and vaginal incisions were clean, as well. Autologous transobturator midurethral sling surgery is a safe, effective and feasible surgical option for stress urinary incontinence in the era which mesh-related concerns are rising. Studies with larger volume and long-term follow up periods are needed.

Advanced Coronary Atherosclerosis and Fatal Myocardial Infarction in Mild Dyslipidemic, Low Risk Young Man: A Case Report With Literature Reviewed

Acute Myocardial infarction (AMI) at a young age (below 45 years) is rare and difficult to predict. We reported a fatal myocardial infarction from advanced atherosclerosis in a healthy young man who had no other major coronary risk factors except mild hypercholesterolemia. Thus, all available systemic risk scores identified him as a low risk candidate for developing a cardiovascular event. Autopsy revealed advanced atherosclerosis in all three major coronary arteries causing acute and old myocardial infarction. Thick epicardial adipose tissue and myocardial bridging of the mid left anterior descending artery were also noted. He frequently used etoricoxib to treat knee and back pain for consecutive five years. Potential mechanisms of sudden death from atherosclerosis, myo- cardial bridging, epicardial adipose tissue and selective COXIB are discussed in more detail below.

Establishing the inter-rater reliability of spinal cord damage manual measurement using magnetic resonance imaging.

Study designRetrospective study.ObjectivesTo establish the inter-rater reliability in the quantitative evaluation of spinal cord damage following cervical incomplete spinal cord injury (SCI) utilizing magnetic resonance imaging (MRI). MRI was used to perform manual measurements of the cranial and caudal boundaries of edema, edema length, midsagittal tissue bridge ratio, axial damage ratio, and edema volume in 10 participants with cervical incomplete SCI.SettingAcademic university setting.MethodsStructural MRIs of 10 participants with SCI were collected from Northwestern University’s Neuromuscular Imaging and Research Lab. All manual measures were performed using OsiriX (Pixmeo Sarl, Geneva, Switzerland). Intraclass correlation coefficients (ICC) were used to determine inter-rater reliability across seven raters of varying experience.ResultsHigh-to-excellent inter-rater reliability was found for all measures. ICC values for cranial/caudal levels of involvement, edema length, midsagittal tissue bridge ratio, axial damage ratio, and edema volume were 0.99, 0.98, 0.90, 0.84, and 0.93, respectively.ConclusionsManual MRI measures of spinal cord damage are reliable between raters. Researchers and clinicians may confidently utilize manual MRI measures to quantify cord damage. Future research to predict functional recovery following SCI and better inform clinical management is warranted.

In vivo evidence of remote neural degeneration in the lumbar enlargement after cervical injury.

ObjectiveTo characterize remote secondary neurodegeneration of spinal tracts and neurons below a cervical spinal cord injury (SCI) and its relation to the severity of injury, the integrity of efferent and afferent pathways, and clinical impairment.MethodsA comprehensive high-resolution MRI protocol was acquired in 17 traumatic cervical SCI patients and 14 controls at 3T. At the cervical lesion, a sagittal T2-weighted scan provided information on the width of preserved midsagittal tissue bridges. In the lumbar enlargement, high-resolution T2*-weighted and diffusion-weighted scans were used to calculate tissue-specific cross-sectional areas and diffusion indices, respectively. Regression analyses determined associations between MRI readouts and the electrophysiologic and clinical measures.ResultsAt the cervical injury level, preserved midsagittal tissue bridges were present in the majority of patients. In the lumbar enlargement, neurodegeneration—in terms of macrostructural and microstructural MRI changes—was evident in the white matter and ventral and dorsal horns. Patients with thinner midsagittal tissue bridges had smaller ventral horn area, higher radial diffusivity in the gray matter, smaller motor evoked potential amplitude from the lower extremities, and lower motor score. In addition, smaller width of midsagittal tissue bridges was also associated with smaller tibialis sensory evoked potential amplitude and lower light-touch score.ConclusionsThis study shows extensive tissue-specific cord pathology in infralesional spinal networks following cervical SCI, its magnitude relating to lesion severity, electrophysiologic integrity, and clinical impairment of the lower extremity. The clinical eloquence of remote neurodegenerative changes speaks to the application of neuroimaging biomarkers in diagnostic workup and planning of clinical trials.

Fibroadhesive scarring of grafted collagen scaffolds interferes with implant-host neural tissue integration and bridging in experimental spinal cord injury.

Severe traumatic spinal cord injury (SCI) results in a devastating and permanent loss of function, and is currently an incurable condition. It is generally accepted that future intervention strategies will require combinational approaches, including bioengineered scaffolds, to support axon growth across tissue scarring and cystic cavitation. Previously, we demonstrated that implantation of a microporous type-I collagen scaffold into an experimental model of SCI was capable of supporting functional recovery in the absence of extensive implant–host neural tissue integration. Here, we demonstrate the reactive host cellular responses that may be detrimental to neural tissue integration after implantation of collagen scaffolds into unilateral resection injuries of the adult rat spinal cord. Immunohistochemistry demonstrated scattered fibroblast-like cell infiltration throughout the scaffolds as well as the presence of variable layers of densely packed cells, the fine processes of which extended along the graft–host interface. Few reactive astroglial or regenerating axonal profiles could be seen traversing this layer. Such encapsulation-type behaviour around bioengineered scaffolds impedes the integration of host neural tissues and reduces the intended bridging role of the implant. Characterization of the cellular and molecular mechanisms underpinning this behaviour will be pivotal in the future design of collagen-based bridging scaffolds intended for regenerative medicine.

Healing Capacity of Autologous Bone Marrow–derived Mesenchymal Stem Cells on Partially Pulpotomized Dogs' Teeth

IntroductionPartial pulpotomy is a vital treatment for carious and traumatic exposure, especially in young permanent teeth. Cell-based therapy for partially pulpotomized teeth can be considered a promising approach for dentin-pulp complex regeneration. This study evaluated the healing capacity of autologous bone marrow–derived stem cells (BMSCs) on partially pulpotomized teeth in a dog model. MethodsTwelve mongrel dogs were selected, and a total number of 192 posterior mandibular and maxillary teeth were involved in the study (16 teeth per dog). Partial pulpotomies were performed, and the dogs were assigned into 2 equal groups (groups 1 and 2), 6 dogs in each group. The coronal pulp cavities (n = 96) of group 1 were filled with calcium silicate–based capping material. Group 2 coronal pulp cavities (n = 96) were seeded with 1 × 105 cell/mL BMSCs, and then the cavities were filled with calcium silicate–based capping material. After placing the capping materials, the cavities of both groups (1 and 2) were filled with resin-modified glass ionomer restorative material. From each group, 48 teeth from 3 dogs were evaluated histologically after 1 week, and the other 48 teeth from the remaining 3 dogs were evaluated after 9 weeks. Scoring was done for the amount of inflammatory cell infiltrates, tissue necrosis, and thickness of hard tissue bridge formation. ResultsThe Mann-Whitney U statistical test performed for hard tissue bridge formation revealed significant differences between the 2 groups at the 1- (P < .05) and 9-week (P < .05) examination periods. ConclusionsAutologous BMSCs have significant therapeutic potential because they enhance the healing capacity of partially pulpotomized dogs' teeth.

MR Spectroscopy of the Cervical Spinal Cord in Chronic Spinal Cord Injury.

Purpose To investigate metabolic changes in chronic spinal cord injury (SCI) by applying MR spectroscopy in the cervical spinal cord. Materials and Methods Single-voxel short-echo spectroscopic data in study participants with chronic SCI and healthy control subjects were prospectively acquired in the cervical spinal cord at C2 above the level of injury between March 2016 and January 2017 and were compared between groups. Concentrations of total N-acetylaspartate (tNAA), myo-inositol (mI), total choline-containing compounds (tCho), creatine, and glutamine and glutamate complex were estimated from the acquired spectra. Participants were assessed with a comprehensive clinical evaluation investigating sensory and motor deficits. Correlation analysis was applied to investigate relationships between observed metabolic differences, lesion severity, and clinical outcome. Results There were 18 male study participants with chronic SCI (median age, 51 years; range, 30-68 years) and 11 male healthy control subjects (median age, 45 years; range, 30-67 years). At cervical level C2, tNAA/mI and tCho/mI ratios were lower in participants with SCI (tNAA/mI: -26%, P = .003; tCho/mI: -18%; P = .04) than in healthy control subjects. The magnitude of difference was greater with the severity of cord atrophy (tNAA/mI: R2 = 0.44, P = .003; tCho/mI: R2 = 0.166, P = .09). Smaller tissue bridges at the lesion site correlated with lower ratios of tNAA/mI (R2 = 0.69, P = .006) and tCho/mI (R2 = 0.51, P = .03) at the C2 level. Lower tNAA/mI and tCho/mI ratios were associated with worse sensory and motor outcomes (P < .05). Conclusion Supralesional metabolic alterations are observed in chronic spinal cord injury, likely reflecting neurodegeneration, demyelination, and astrocytic gliosis in the injured cervical cord. Lesion severity and greater clinical impairment are both linked to the biochemical changes in the atrophied cervical cord after spinal cord injury. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Lin in this issue.

Proepicardium: Current Understanding of its Structure, Induction, and Fate.

The proepicardium (PE) is a transitory extracardiac embryonic structure which plays a crucial role in cardiac morphogenesis and delivers various cell lineages to the developing heart. The PE arises from the lateral plate mesoderm (LPM) and is present in all vertebrate species. During development, mesothelial cells of the PE reach the naked myocardium either as free-floating aggregates in the form of vesicles or via a tissue bridge; subsequently, they attach to the myocardium and, finally, form the third layer of a mature heart-the epicardium. After undergoing epithelial-to-mesenchymal transition (EMT) some of the epicardial cells migrate into the myocardial wall and differentiate into fibroblasts, smooth muscle cells, and possibly other cell types. Despite many recent findings, the molecular pathways that control not only proepicardial induction and differentiation but also epicardial formation and epicardial cell fate are poorly understood. Knowledge about these events is essential because molecular mechanisms that occur during embryonic development have been shown to be reactivated in pathological conditions, for example, after myocardial infarction, during hypertensive heart disease or other cardiovascular diseases. Therefore, in this review we intended to summarize the current knowledge about PE formation and structure, as well as proepicardial cell fate in animals commonly used as models for studies on heart development. Anat Rec, 302:893-903, 2019. © 2018 Wiley Periodicals, Inc.

Effect of Residual Dental Pulp Tissue on Regeneration of Dentin-pulp Complex: An In Vivo Investigation

IntroductionCurrent pulp revascularization procedures in teeth with necrotic pulps and open apices have produced histologic evidence of connective tissue growth, cementum, and bone within the root canals of experimental animals. This study aims to investigate the effect of maintaining uninflamed residual apical pulp tissue on the histologic outcome of pulp-dentin complex regeneration after a revascularization procedure in immature ferret cuspid teeth. MethodsTwenty-eight cuspid teeth from 7 young male ferrets were used in this experiment. Seven teeth were reserved to serve as positive control samples without any treatment. In another 7 teeth, the pulp was completely extirpated (negative control), whereas the pulp of the remaining 14 teeth were removed to either 1–2 mm short of the apex (7 samples) or 2–4 mm short of the apex (7 samples). Blood clots were covered with mineral trioxide aggregate at the cementoenamel junction level of each tooth. Three months later, block sections were removed for histologic evaluations, and the data were statistically analyzed with the chi-square test (P < .05). ResultsAll teeth with complete pulp extirpation showed the presence of bone inside the root canal. In contrast, the root canals for most teeth with pulp amputation 1–4 mm from the radiographic apex were filled with normal pulp, which extended coronally to the mineral trioxide aggregate, where hard tissue bridges had formed. ConclusionsBased on these results, we concluded that regeneration of the pulp-dentin complex is possible when the apical 1–4 mm of the apical pulp remains intact in immature teeth.

Low-pressure micro-mechanical re-adaptation device sustainably and effectively improves locomotor recovery from complete spinal cord injury

Traumatic spinal cord injuries result in impairment or even complete loss of motor, sensory and autonomic functions. Recovery after complete spinal cord injury is very limited even in animal models receiving elaborate combinatorial treatments. Recently, we described an implantable microsystem (microconnector) for low-pressure re-adaption of severed spinal stumps in rat. Here we investigate the long-term structural and functional outcome following microconnector implantation after complete spinal cord transection. Re-adaptation of spinal stumps supports formation of a tissue bridge, glial and vascular cell invasion, motor axon regeneration and myelination, resulting in partial recovery of motor-evoked potentials and a thus far unmet improvement of locomotor behaviour. The recovery lasts for at least 5 months. Despite a late partial decline, motor recovery remains significantly superior to controls. Our findings demonstrate that microsystem technology can foster long-lasting functional improvement after complete spinal injury, providing a new and effective tool for combinatorial therapies.

Modified Palatal Flap with a Tissue Bridge in the Closure of the Oroantral Fistulae: A Prospective Study

An oroantral fistula is by definition 'An abnormal communication between the oral cavity and the maxillary sinus.' The aim of this study is to describe the acute and chronic OAFs and to evaluate the efficiency of the modified palatal flaps with tissue bridge in the closure of both acute and chronic OAFs of small to medium size. The study sample was derived from a population of patients from January 2013 to 2018 with the complaint of pain and discharge through the socket. The results of this series support the view that the use of modified palatal flap with tissue bridge is a reliable flap for the repair of both acute and chronic oroantral fistulae. The ease of mobilization, superior blood supply and minimal donor site morbidity make it an ideal flap and a reliable alternative when other techniques fail.

Human Cartilage-Derived Progenitors Resist Terminal Differentiation and Require CXCR4 Activation to Successfully Bridge Meniscus Tissue Tears.

Meniscus injuries are among the most common orthopedic injuries. Tears in the inner one‐third of the meniscus heal poorly and present a significant clinical challenge. In this study, we hypothesized that progenitor cells from healthy human articular cartilage (chondroprogenitor cells [C‐PCs]) may be more suitable than bone‐marrow mesenchymal stem cells (BM‐MSCs) to mediate bridging and reintegration of fibrocartilage tissue tears in meniscus. C‐PCs were isolated from healthy human articular cartilage based on their expression of mesenchymal stem/progenitor marker activated leukocyte cell adhesion molecule (ALCAM) (CD166). Our findings revealed that healthy human C‐PCs are CD166+, CD90+, CD54+, CD106‐ cells with multilineage differentiation potential, and elevated basal expression of chondrogenesis marker SOX‐9. We show that, similar to BM‐MSCs, C‐PCs are responsive to the chemokine stromal cell‐derived factor‐1 (SDF‐1) and they can successfully migrate to the area of meniscal tissue damage promoting collagen bridging across inner meniscal tears. In contrast to BM‐MSCs, C‐PCs maintained reduced expression of cellular hypertrophy marker collagen X in monolayer culture and in an explant organ culture model of meniscus repair. Treatment of C‐PCs with SDF‐1/CXCR4 pathway inhibitor AMD3100 disrupted cell localization to area of injury and prevented meniscus tissue bridging thereby indicating that the SDF‐1/CXCR4 axis is an important mediator of this repair process. This study suggests that C‐PCs from healthy human cartilage may potentially be a useful tool for fibrocartilage tissue repair/regeneration because they resist cellular hypertrophy and mobilize in response to chemokine signaling. stem cells 2019;37:102–114

Recovery after spinal cord injury by modulation of the proteoglycan receptor PTPσ

SCI is followed by dramatic upregulation of chondroitin sulfate proteoglycans (CSPGs) which limit axonal regeneration, oligodendrocyte replacement and remyelination. The recent discovery of the specific CSPGs signaling receptor protein tyrosine phosphatase sigma (RPTPσ) provided an opportunity to refine the therapeutic approach to overcome CSPGs inhibitory actions. In previously published work, subcutaneous (s.c.) delivery of 44 μg/day of a peptide mimetic of PTPσ called intracellular sigma peptide (ISP), which binds to PTPσ and blocks CSPG-mediated inhibition, facilitated recovery after contusive SCI. Since this result could be of great interest for clinical trials, we independently repeated this study, but modified the method of injury as well as peptide application and the dosage. Following SCI at the Th10-segment, 40 rats were distributed in 3 groups. Animals in group 1 (20 rats) were subjected to SCI, but received no treatment. Rats in group 2 were treated with intraperitoneal (i.p.) injections of 44 μg/day ISP (SCI + ISP44) and animals of group 3 with s.c. injections of 500 μg/day ISP (SCI + ISP500) for 7 weeks after lesioning. Recovery was analyzed at 1, 3, 6, 9 and 12 weeks after SCI by determining (i) BBB-score, (ii) foot-stepping angle, (iii) rump-height index, (iv) number of correct ladder steps, (v) bladder score and (vi) sensitivity (withdrawal latency after thermal stimulus). Finally, we determined the amount of serotonergic fibers in the preserved neural tissue bridges (PNTB) around the lesion site. Our results show that, systemic therapy with ISP improved locomotor, sensory and vegetative recovery which correlated with more spared serotonergic fibers in PNTB.

Vascularization of Natural and Synthetic Bone Scaffolds

Vascularization of engineered bone tissue is critical for ensuring its survival after implantation. In vitro pre-vascularization of bone grafts with endothelial cells is a promising strategy to improve implant survival. In this study, we pre-cultured human smooth muscle cells (hSMCs) on bone scaffolds for 3 weeks followed by seeding of human umbilical vein endothelial cells (HUVECs), which produced a desirable environment for microvasculature formation. The sequential cell-seeding protocol was successfully applied to both natural (decellularized native bone, or DB) and synthetic (3D-printed Hyperelastic “Bone” scaffolds, or HB) scaffolds, demonstrating a comprehensive platform for developing natural and synthetic-based in vitro vascularized bone grafts. Using this sequential cell-seeding process, the HUVECs formed lumen structures throughout the DB scaffolds as well as vascular tissue bridging 3D-printed fibers within the HB. The pre-cultured hSMCs were essential for endothelial cell (EC) lumen formation within DB scaffolds, as well as for upregulating EC-specific gene expression of HUVECs grown on HB scaffolds. We further applied this co-culture protocol to DB scaffolds using a perfusion bioreactor, to overcome the limitations of diffusive mass transport into the interiors of the scaffolds. Compared with static culture, panoramic histological sections of DB scaffolds cultured in bioreactors showed improved cellular density, as well as a nominal increase in the number of lumen structures formed by ECs in the interior regions of the scaffolds. In conclusion, we have demonstrated that the sequential seeding of hSMCs and HUVECs can serve to generate early microvascular networks that could further support the in vitro tissue engineering of naturally or synthetically derived bone grafts and in both random (DB) and ordered (HB) pore networks. Combined with the preliminary bioreactor study, this process also shows potential to generate clinically sized, vascularized bone scaffolds for tissue and regenerative engineering.

Cross-linked electrospun cartilage acellular matrix/poly(caprolactone-co-lactide-co-glycolide) nanofiber as an antiadhesive barrier

In this work, we chose cartilage acellular matrix (CAM) as a promising antiadhesive material because CAM effectively inhibits the formation of blood vessels, and we used electrospinning to prepare antiadhesive barriers. Additionally, we synthesized N-hydroxysuccinimide (NHS)-poly(caprolactone-co-lactide-co-glycolide)-NHS (MP) copolymers (to tune degradation) as a cross-linking agent for CAM. This is the first report on the development of electrospun cross-linked (Cx) CAM/MP (CA/P) nanofiber (NF) (Cx-CA/P-NF) with a tunable degradation period as an antiadhesive barrier. Compared with the CA/P-NF before cross-linking, the electrospun Cx-CA/P-NF after cross-linking showed different biodegradation. Cx-CA/P-NF significantly inhibited the in vitro attachment and proliferation of human umbilical vein endothelial cells (HUVECs), as confirmed by an MTT assay and scanning electron microscopy images. Cx-CA/P-NFs implanted between a surgically damaged peritoneal wall and cecum gradually degraded in 7 days; this process was monitored by NIR imaging. The in vivo evaluation of the anti–tissue adhesive effect of Cx-CA/P-NFs revealed little adhesion, few blood vessels, and negligible inflammation at 7 days determined by hematoxylin and eosin staining. ED1 staining of Cx-CA/P-NFs showed infiltration of few macrophages because of the inflammatory response to the Cx-CA/P-NF as compared with an untreated injury model. Additionally, Cx-CA/P-NFs significantly suppressed the formation of blood vessels between the peritoneal wall and cecum, according to CD31 staining. Overall, Cx-CA/P-NFs yielded little adhesion, infiltration by macrophages, or formation of blood vessels in a postoperative antiadhesion assay. Thus, it is reasonable to conclude that the Cx-CA/P-NF designed herein successfully works as an antiadhesive barrier with a tunable degradation period. Statement of SignificanceThe cartilage acellular matrix (CAM) can inhibit the formation of fibrous tissue bridges and blood vessels between the tissue at an injured site and the surrounding healthy tissues. However, CAM has not been rigorously investigated as an antiadhesive barrier. In this manuscript, the cross-linked CAM nanofiber (Cx-CA/P-NF) designed herein successfully works as an antiadhesive barrier. Cx-CA/P-NFs yielded little adhesion, infiltration by macrophages, or formation of blood vessels in a postoperative antiadhesion assay. Moreover, we demonstrated the suitable properties of Cx-CA/P-NF such as easy cross-linking by maintaining the antiadhesive properties, controllable biodegradation, and in vivo antiadhesive effect of Cx-CA/P-NF.

Force Modulating Tissue Bridges for Reduction of Tension and Scar: Finite Element and Image Analysis of Preclinical Incisional and Nonincisional Models.

BackgroundForce modulating tissue bridges (FMTB) represent a new class of combined wound closure and scar reduction device designed to optimize the tension milieu of the healing wound.ObjectivesEngineering analysis and testing in both intact skin and incisional models was undertaken to assess changes in tissue tension associated with device placement and compare to standard suture closure.MethodsNonlinear, large deformation finite element analyses (FEA) were performed to compare the strains applied to tissues with sutures and FMTB. In the incisional model, a freshly euthanized Yorkshire pig received full thickness cutaneous incisions followed by alternating closure with sutures and FMTBs. FMTBs were also applied to intact adult human skin after pattern application. In each of the experiments, photographs were taken preapplication and postapplication and the resultant dot grid pattern changes were analyzed by image recognition algorithms to calculate applied strains.ResultsFEA indicate compressive stresses at the tissue:suture interface on the order of 4000 mmHg and 20 mmHg at the tissue:FMTB interface. Strain analysis of the sutures and FMTBs applied in the incisional lab testing indicated imposed strains on the tissues of around 40%, with FMTBs providing 10% more compression than sutures and 25% more compression between the applied devices (P = 0.000057). In the longitudinal study, tension reduction of the order of 30% was maintained over the treatment period of 10 days to verify device efficacy.ConclusionsFMTBs provide wounds while simultaneously modulating skin tension and thus have the potential to improve scar appearance.

PD21-11 PLACENTAL MEMBRANE GRAFTS FOR THE TREATMENT OF URETHRAL STRICTURES IN A RABBIT MODEL

You have accessJournal of UrologyTrauma/Reconstruction/Diversion: Urethral Reconstruction (including Stricture, Diverticulum) I1 Apr 2018PD21-11 PLACENTAL MEMBRANE GRAFTS FOR THE TREATMENT OF URETHRAL STRICTURES IN A RABBIT MODEL Chad Pusateri, Alexander Doudt, Steven Gauerke, Britini Ork, Xiaofei Qin, Joseph Khoury, Kurt McCammon, and Jack Zuckerman Chad PusateriChad Pusateri More articles by this author , Alexander DoudtAlexander Doudt More articles by this author , Steven GauerkeSteven Gauerke More articles by this author , Britini OrkBritini Ork More articles by this author , Xiaofei QinXiaofei Qin More articles by this author , Joseph KhouryJoseph Khoury More articles by this author , Kurt McCammonKurt McCammon More articles by this author , and Jack ZuckermanJack Zuckerman More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2018.02.1166AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Several graft materials are available for use in the treatment of urethral stricture disease. Placental membrane is being used in a variety of settings as a tissue bridge in wound healing. We aim to evaluate the effect of implanting decellularized human placental membrane into rabbit urethras. We hypothesize that the urethra will remain patent on cystoscopic examination, urothelial replacement of the placental membrane graft will be observed, and no malignant transformation will be identified. METHODS Dorsal onlay free graft urethroplasties utilizing harvested and prepared human placental membrane were performed in 10 New Zealand White rabbits (oryctolagus ouniculus). After three months, the rabbits underwent cystourethroscopy to evaluate urethral patency. The rabbits were then euthanized and the urethras were examined pathologically. RESULTS All urethroplasties were performed without complication. Mean catheter time was 5.1 days (1-7). Postoperative hematuria was noted in one rabbit. There were no observed episodes of urinary retention, infection, or renal failure. No stricture formations were observed on cystourethroscopy. On pathologic examination, urothelial replacement was observed in all ten rabbits without malignant transformation. CONCLUSIONS Dorsal onlay urethroplasty using decellularized human placental membrane can safely be performed in a rabbit model. This pilot study demonstrated urothelial replacement of human placental membrane in the rabbit urethra without stricture formation. Additional studies are needed to validate placental membrane as a potential graft material. © 2018FiguresReferencesRelatedDetails Volume 199Issue 4SApril 2018Page: e472 Advertisement Copyright & Permissions© 2018MetricsAuthor Information Chad Pusateri More articles by this author Alexander Doudt More articles by this author Steven Gauerke More articles by this author Britini Ork More articles by this author Xiaofei Qin More articles by this author Joseph Khoury More articles by this author Kurt McCammon More articles by this author Jack Zuckerman More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...