In Vivo assessment of a tissue-engineered vascular graft combining a biodegradable elastomeric scaffold and muscle-derived stem cells in a rat model

Limited autologous vascular graft availability and poor patency rates of synthetic grafts for bypass or replacement of small-diameter arteries remain a concern in the surgical community. These limitations could potentially be improved by a tissue engineering approach. We report here our progress in the development and in vivo testing of a stem-cell-based tissue-engineered vascular graft for arterial applications. Poly(ester urethane)urea scaffolds (length=10mm; inner diameter=1.2mm) were created by thermally induced phase separation (TIPS). Compound scaffolds were generated by reinforcing TIPS scaffolds with an outer electrospun layer of the same biomaterial (ES-TIPS). Both TIPS and ES-TIPS scaffolds were bulk-seeded with 10×106 allogeneic, LacZ-transfected, muscle-derived stem cells (MDSCs), and then placed in spinner flask culture for 48h. Constructs were implanted as interposition grafts in the abdominal aorta of rats for 8 weeks. Angiograms and histological assessment were performed at the time of explant. Cell-seeded constructs showed a higher patency rate than the unseeded controls: 65% (ES-TIPS) and 53% (TIPS) versus 10% (acellular TIPS). TIPS scaffolds had a 50% mechanical failure rate with aneurysmal formation, whereas no dilation was observed in the hybrid scaffolds. A smooth-muscle-like layer of cells was observed near the luminal surface of the constructs that stained positive for smooth muscle α-actin and calponin. LacZ+ cells were shown to be engrafted in the remodeled construct. A confluent layer of von Willebrand Factor-positive cells was observed in the lumen of MDSC-seeded constructs, whereas acellular controls showed platelet and fibrin deposition. This is the first evidence that MDSCs improve patency and contribute to the remodeling of a tissue-engineered vascular graft for arterial applications. © 2010 Mary Ann Liebert, Inc

Ablación por radiofrecuencia en esófago de Barrett. Experiencia Inicial

La radiofrecuencia endoscópica utiliza energía térmica para ablacionar la capa superficial del esófago donde se localiza el tejido característico del Esófago de Barrett (EB). Pacientes y métodos. Se incluyeron 50 pacientes adultos con diagnóstico de EB de acuerdo a la clasificación de Viena. Objetivos. Se evaluó la seguridad y la eficacia de la ablación por radio-frecuencia (ARF) en pacientes con EB. Resultados. Fueron tratados 50 pacientes con una mediana de seguimiento de 18 meses. La mediana de edad fue de 58 años. Hasta lograr la erradicación del EB se realizaron 1,4 sesiones de ARF por paciente. La morbilidad del procedimiento fue del 6% y la complicación más frecuente fue la estenosis esofágica (dos casos). No se observó recurrencia de la metaplasia intestinal durante el seguimiento. Conclusiones. En nuestra experiencia la ARF es un procedimiento seguro con baja morbilidad. Los resultados a mediano y largo plazo publicados son estimulantes y permiten comenzar a reevaluar los protocolos de seguimiento vigentes

Electrical stimulation of the lower esophageal sphincter to address gastroesophageal reflux disease after sleeve gastrectomy.

BACKGROUND Laparoscopic sleeve gastrectomy (LSG) can result in de novo and worsen preexisting gastroesophageal reflux disease (GERD). Post-LSG patients with GERD refractory to proton pump inhibitors (PPI) usually undergo more invasive, anatomy-altering Roux-en-Y gastric bypass surgery. Lower esophageal sphincter (LES) electrical stimulation (ES) preserves the anatomy and has been shown to improve outcomes in GERD patients. OBJECTIVE To evaluate the safety and efficacy of LES-ES in post-LSG patients with GERD not controlled with maximal PPI therapy. SETTING Prospective, international, multicenter registry. METHODS Patients with LSG-associated GERD partially responsive to PPI underwent LES-ES. GERD outcomes pre- and poststimulation were evaluated based on quality of life, esophageal acid exposure (after 6-12 mo), and PPI use. RESULTS Seventeen patients (11 female, 65%), treated at 6 centers between May 2014 and October, 2016 with a median follow-up of 12 months (range 6-24), received LES-ES. Median age was 48.6 years (interquartile range, 40.5-56), median body mass index 31.7 kg/m (27.9-39.3). All patients were on at least daily PPI preoperatively; at last follow-up, 7 (41%) were completely off PPI, 5 (29%) took PPI on an intermittent basis, and 5 (29%) were on single-dose PPI. Median GERD-health-related quality of life scores improved from 34 (on-PPI, 25-41) at baseline to 9 (6-13) at last follow-up (off-PPI, P<.001). Percentage of time with esophageal pH<4 improved from 13.2% (3.7-30.7) to 5.8% (1.1-54.4), P = .01. CONCLUSION LES-ES in post-LSG patients suffering from symptomatic, PPI-refractory GERD resulted in significant improvement of GERD-symptoms, esophageal acid exposure, and need for PPI. Preserving the post-LSG anatomy, it offers a valid option for patients unable or unwilling to undergo Roux-en-Y gastric bypass surgery

Urinary bladder matrix scaffolds strengthen esophageal hiatus repair

Background: Laparoscopic repair of the hiatal hernia is associated with a recurrence rate between 12% and 42% depending on the defect size. Although the impact of hiatal reinforcement on long-term recurrence remains controversial, the main limitation of this approach has been the risk of adverse events related with the use of synthetic materials in the vicinity of the esophagus. Methods: A total of 14 female domestic pigs underwent laparoscopic primary hiatal hernia repair of a simulated defect in the esophageal hiatus. Seven of the hiatal repairs were reinforced with an extracellular matrix (ECM) scaffold, whereas the remaining seven served as primary repair controls. Animals were survived for 8 wk. At necropsy, after gross morphologic evaluation, samples were sent for mechanical testing and histology. Results: The repaired defect site reinforced with ECM scaffolds showed a robust closure of the crura in all cases with a smooth peritoneal-like structure covering the entire repair. Average load at failure of the treated group was found to be significantly stronger than that of the controls (185.8 149.7 g versus 57.5 57.5 g, P < 0.05). Similarly, the stiffness was significantly higher in the treated animals (57.5 26.9 g/mm versus 19.1 17.5 g/mm; P < 0.01). Interestingly, there was no difference in elongation at failure (7.62 2.02 mm versus 7.87 3.28 mm; P ¼ 0.44). Conclusions: In our animal survival model, we have provided evidence that the addition of an ECM to augment a primary hiatal repair leads to tissue characteristics that may decrease the possibility of early failure of the repair. This may translate to decreased recurrence rates. Further study is necessary.Fil: Riganti, Juan Martin. Fundación Favaloro; ArgentinaFil: Citola, F. Fundación Favaloro; ArgentinaFil: Amenabar, A. Fundación Favaloro; ArgentinaFil: Craiem, Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Graf, S. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Badaloni, A. Fundación Favaloro; ArgentinaFil: Gilbert, TW. University of Pittsburgh; Estados Unidos. ACell; Estados UnidosFil: Nieponice, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; Argentina. Fundación Favaloro; Argentin