Modelo animal para la evaluación del sellado de colaterales venosas con dispositivos liberadores de energía en cirugía de revascularización / Animal model to assess collateral vein sealing with energy-based devices in revascularization surgery

Introducción: los dispositivos liberadores de energía permiten la hemostasia de los vasos mediante generación de calor y la coagulación de las proteínas de la pared. Sin embargo, se desconoce su comportamiento a medio plazo en la cirugía arterial con injertos venosos. Objetivos: desarrollar un modelo animal que permita evaluar la eficacia y seguridad del sellado a medio plazo tras el proceso de cicatrización. Comparar y evaluar qué modelo in vivo presenta menor morbilidad y mayor supervivencia a las 4 semanas. Material y métodos: estudio experimental animal de 16 conejos New Zealand a los que se interpuso un fragmento de vena safena humana (VS) con una colateral. Se desarrollaron dos modelos arteriales: bypass termino-terminal de VS en aorta infrarrenal (n = 5) y plastia de aorta con parche de VS (n = 11). La colateral venosa fue sellada, previa aleatorización, con electrocoagulación bipolar controlada por temperatura (EB) o bisturí armónico (BA). Todos los animales recibieron inmunosupresión y profilaxis antitrombótica. Se registró la tasa de paraplejia, de infección, de hemorragia y de supervivencia. Resultados: la supervivencia a los 7 días fue del 50 % (2/4) en el modelo de injerto de interposición. Sin embargo, ningún animal sobrevivió a las 4 semanas de seguimiento en este modelo. En el grupo de plastia de aorta, la supervivencia a los 7 días fue del 55,56 % (5/9) y del 44,44 % (4/9) a las 4 semanas (p = 0,5). La tasa de paraplejia en el grupo de interposición fue del 100 % e inferior en el modelo de plastia de aorta (25 %) (p = 0,03). El tiempo medio de isquemia en el modelo de plastia de aorta (37,11 ± 8,1 min) fue inferior al del grupo del bypass (42 ± 10,61 min) (p = 0,414). En ningún caso se objetivó hemorragia intraabdominal ni reacción adversa a la inmunosupresión. Conclusiones: el modelo arterial de plastia de aorta con parche de VS presentó menor tasa de paraplejia, así como menor mortalidad posoperatoria a los 7 días...(AU)

Introduction: energy sealing devices achieve hemostasis of the vessels through the heat generated and coagula-tion of the vascular wall proteins. However, the mid-term efficacy profile for venous graft sealing in arterial bypasssurgery remains unknown.Objectives: to create an animal model to compare the mid-term efficacy and safety profile at the sealing areaafter the healing process. To compare and assess which in vivo arterial models show lower morbidity and highersurvival rates after 4 weeks.Material and methods: this was an in vivo experimental study of 16 New Zealand rabbits. In each rabbit a humansaphenous vein (SV) with, at least, 1 venous collateral was implanted. Two arterial models were developed: infrarre-nal aorta bypass with SV (n = 5) and aortoplasty with SV patch (n = 11). In both models the collateral was randomizedand sealed with either 1 these 2 energy sealing devices: electrothermal bipolar vessel sealing (EBVS) or Harmonicscalpel (HS). Every animal was treated with antithrombotic prophylaxis and immunosuppressive medication. Therates of intraoperative mortality, paraplegia, infection, bleeding, and survival were all studied.Results: two animals (50 %) survive 7 days after surgery in the bypass model. However, no animal survived 4 daysafter surgery in this model. In the aortoplasty group, the 7-day survival rate was 55.56 % (5/9) while the 4-weeksurvival rate was 44.44 % (4/9) (p = 0.05). The rate of paraplegia was 100 % for the bypass model and much lowerfor the patch group (25 %) (p = 0.03). The mean ischemic time was lower for the aortoplasty model (37.11 ± 8.1 min)compared to the bypass group (42 ± 10.61 min) (p = 0.414). No animal showed intrabdominal hemorrhages oradverse drug reactions associated with the immunosuppressive medication.Conclusion: aortoplasty with the SV patch model showed lower rates of paraplegia and 7-day mortality in theanimal model...(AU)

Human adipose-derived mesenchymal stem cells accelerate decellularized neobladder regeneration.

Decellularized natural bladder matrices (neobladders) represent an exciting means to regenerate the bladder following bladder cancer-associated cystectomy. In this study, we compare the evolution of decellularized matrices with recellularized matrices by seeding it with human adipose-derived mesenchymal stem cells (ADSC) after implantation following partial cystectomy in rats. We discovered significant anatomical differences since 10 days after neobladder implantation with the ADSC-containing matrices promoting a significant recovery of mature p63- and cytokeratin 7-positive urothelium. We also discovered significantly induced expression of the vimentin mesoderm marker in the submucosal layer in ADSC-seeded matrices. Interestingly, we found a higher expression of smooth muscle actin in transversal and longitudinal smooth muscle layers with ADSC-seeded matrices. Furthermore, ADSC also showed increased vascularization and nerve innervation of the neobladder as determined by the distribution of CD31 and S100ß reactivity, respectively. We believe that ADSC and their paracrine-acting pro-regenerative secretome within decellularized matrices represent an efficient bladder substitution strategy; however, we require a fuller understanding of the mechanisms involved before clinical studies can begin.

Experimental cell transplantation for traumatic spinal cord injury regeneration: intramedullar or intrathecal administration.

Animal experimentation models are a necessary prerequisite to human trials for the use of regenerative medicine in the treatment of spinal cord injuries. Considerable effort is required for the generation of a consistent and reproducible methodology to incur an injury and evaluate the results. The traumatic contusion model has been accepted as a model that closely mimics a typical human traumatic injury, and here we detail step by step an approach to generate a reproducible lesion in rats. Acute cell transplantation by intramedullar or intrathecal administration is described for regenerative interventions. The same model is suitable to design subacute or chronic therapeutic approaches by interventions 1 week or 1 month after lesion.