22 results match your criteria: "Stanford University. Electronic address: jdunn2@stanford.edu.[Affiliation]"
Distraction Enterogenesis Induces Desert Hedgehog in the Lengthened Murine Colon.
J Pediatr Surg
December 2024
Department of Surgery, Stanford University, Stanford, CA, United States; Division of Bioengineering, Stanford University, Stanford, CA, United States. Electronic address:
Background: Distraction enterogenesis lengthens the intestine through applied mechanical stress. The Hedgehog pathway (Hh) is responsible for intestinal tract development and directing the multi-layer patterning of the intestinal lumen. This study investigates the alteration in the principal components of this pathway in spring-mediated colonic lengthening.
View Article and Find Full Text PDFPerioperative Gastrointestinal Myoelectric Activity Measurement Using Wireless External Patches.
J Surg Res
October 2024
Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California; Department of Bioengineering, Stanford University, Stanford, California. Electronic address:
Background: Stomach, small intestine, and colon have distinct patterns of contraction related to their function to mix and propel enteric contents. In this study, we aim to measure gut myoelectric activity in the perioperative course using external patches in an animal model.
Methods: Four external patches were placed on the abdominal skin of female Yucatan pigs to record gastrointestinal myoelectric signals for 3 to 5 d.
Importance of Ileum and Colon in Children with Short Bowel Syndrome.
J Pediatr Surg
July 2023
Division of Pediatric Surgery, Department of Surgery, Stanford University, Stanford, CA, USA. Electronic address:
Background: It is well known that small bowel length is a dominant prognostic indicator in patients with short bowel syndrome (SBS). The relative importance of jejunum, ileum, and colon is less well defined in children with SBS. Here we review the outcome of children with SBS with respect to the type of remnant intestine.
View Article and Find Full Text PDFLong-term safety of intraluminal spring-mediated bowel lengthening.
J Pediatr Surg
January 2023
Division of Pediatric Surgery, Stanford University, Stanford, CA, USA; Eclipse Regenesis, Mountain View, CA, USA; Department of Bioengineering, Stanford University, Stanford, CA, USA. Electronic address:
Article Synopsis
- - The study aimed to assess the long-term safety and effectiveness of a bowel lengthening device before initiating human trials, focusing on its performance and ability for natural passage.
- - The device was surgically implanted in Yucatan minipigs, with observations conducted weekly to monitor weight and device position, and animals were euthanized at different time intervals for analysis.
- - Results showed no serious complications, successful passage of the device within 180 days, and consistent bowel lengthening with minimal tissue damage observed over the study period.
Generation of Porcine Ileum Through Spring-Mediated Mechanical Distraction.
J Surg Res
December 2022
Division of Pediatric Surgery, Stanford University, Stanford, California; Department of Bioengineering, Stanford University, Stanford, California. Electronic address:
Article Synopsis
- * In a controlled experiment with juvenile pigs, a nitinol spring was inserted into the ileum and monitored for structural and functional preservation during a week-long recovery period after surgery.
- * Results showed significant lengthening of the ileum, with no adverse effects on the pigs, suggesting potential improvements in intestinal function and hormonal activity due to increased enteroendocrine cell density.
Gastrointestinal Myoelectric Measurements via Simultaneous External and Internal Electrodes in Pigs.
J Surg Res
November 2022
Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California; Department of Bioengineering, Stanford University, Stanford, California. Electronic address:
Introduction: Currently, there is no accurate noninvasive measurement system to diagnose gastrointestinal (GI) motility disorders. Wireless skin patches have been introduced to provide an accurate noninvasive measurement of GI myoelectric activity which is essential for developing neuro-stimulation devices to treat GI motility disorders. The aim of this study is to compare the external and internal electrical signal measurements in ambulatory pigs.
View Article and Find Full Text PDFDistraction enterogenesis in the murine colon.
J Pediatr Surg
July 2022
Department of Surgery, Stanford University, Stanford, CA, United States; Division of Bioengineering, Stanford University, Stanford, CA, United States. Electronic address:
Background/purpose: Distraction enterogenesis with intraluminal spring technology has been successfully used to lengthen segments of murine small intestine. We hypothesized that biocompatible springs could also be used to lengthen murine large intestine.
Methods: Age and weight matched C57BL/6 mice underwent surgical insertion of nitinol spring-loaded capsules into the cecum.
Mechanical lengthening of porcine small intestine with decreased forces.
J Pediatr Surg
July 2021
Division of Pediatric Surgery, Stanford University School of Medicine, 453 Quarry Road, MC 5733, Stanford, CA 94304, United States. Electronic address:
Introduction: short bowel syndrome is marked by inadequate intestinal surface area to absorb nutrients. Current treatments are focused on medical management and surgical reconfiguration of the dilated intestine. We propose the use of spring-mediated distraction enterogenesis as a novel intervention to increase intestinal length.
View Article and Find Full Text PDFMesenteric neovascularization during spring-mediated intestinal lengthening.
J Pediatr Surg
January 2021
Department of Surgery, Division of Pediatric Surgery, Stanford University School of Medicine, Stanford, CA, USA. Electronic address:
Background: Short gut syndrome, a condition characterized by inadequate absorption of nutrients owing to decreased bowel length, has minimal avenues for treatment. We have proposed spring-mediated distraction enterogenesis to lengthen bowel in porcine jejunum as a treatment for short gut. We aim to evaluate the extent of mesenteric neovascularization in segments of lengthened bowel via spring-mediated enterogenesis.
View Article and Find Full Text PDFIrreversible Electroporation for De-epithelialization of Murine Small Intestine.
J Surg Res
December 2020
Division of Pediatric Surgery, Stanford University School of Medicine, Stanford, California. Electronic address:
Background: Nonthermal irreversible electroporation (NTIRE) has been shown to ablate the small intestinal epithelium while maintaining submucosal and muscularis propriae integrity. NTIRE is used here in a first-in-mouse study to eliminate the native intestinal stem cell population to understand optimal parameters and timeline of mucosal regeneration.
Methods: Adult C57 background mice underwent laparotomy and electroporation of 1.
Intestinal adaptation following spring insertion into a roux limb in mice.
J Pediatr Surg
February 2021
Department of Surgery, Stanford University, Stanford, CA; Division of Bioengineering, Stanford University, Stanford, CA. Electronic address:
Background/purpose: Intraluminal springs have recently been shown to lengthen segments of intestine in a process known as distraction enterogenesis. We hypothesized that biocompatible springs could be used to lengthen defunctionalized murine small intestine and would lead to identifiable intestinal adaptations at the molecular level.
Methods: Age and weight matched C57BL/6 mice underwent surgical insertion of nitinol spring-loaded capsules into a Roux limb of jejunum.
Human skin-derived precursor cells xenografted in aganglionic bowel.
J Pediatr Surg
December 2020
Division of Pediatric Surgery, Department of Surgery, School of Medicine, Stanford University, Division of Pediatric Surgery, 300 Pasteur Drive, Alway M116, Stanford, CA 94305. Electronic address:
Article Synopsis
- Hirschsprung disease affects 1 in 5000 newborns annually in the U.S., and researchers are exploring using neural crest stem cells to restore the enteric nervous system.
- Human skin-derived precursor cells (hSKPs) were cultured and injected into juvenile minipigs with chemically induced aganglionosis to study their behavior post-transplantation.
- After a week, hSKPs were found in the pig's colons, showing signs of neuroglial differentiation, indicating their potential for treating Hirschsprung disease.
Autologous Transplantation of Skin-Derived Precursor Cells in a Porcine Model.
J Pediatr Surg
January 2020
Division of Pediatric Surgery, Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles; Division of Pediatric Surgery, Department of Surgery, School of Medicine, Stanford University. Electronic address:
Article Synopsis
- Hirschprung's disease involves the absence of nerve cells in the bowel, often requiring surgery; researchers are looking at cell-based therapies using skin-derived precursor cells (SKPs) as a potential alternative treatment.
- In a study, juvenile pigs had skin cells harvested and injected into sections of their colon lacking nerve ganglia, with assessments made on the cells' capabilities both before and after transplantation.
- Results showed that SKPs were able to express markers indicating they had differentiated into nerve and glial cells, suggesting that using these cells could be a promising cell-based therapy for related gastrointestinal disorders.
Optimization of In-Continuity Spring-Mediated Intestinal Lengthening.
J Pediatr Surg
January 2020
Division of Pediatric Surgery, Department of Surgery, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA; Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California, USA. Electronic address:
Background: Spring-mediated intestinal lengthening has been studied in numerous animal models to effectively achieve up to a 3-fold increase in length. In this study we are interested in optimizing this method of spring lengthening.
Methods: Juvenile mini-Yucatan pigs underwent laparotomy for spring implantation.
Biomechanical signaling and collagen fiber reorientation during distraction enterogenesis.
J Mech Behav Biomed Mater
January 2020
Department of Surgery, Division of Pediatric Surgery, Stanford University School of Medicine, Stanford, CA, USA; Department of Bioengineering, Stanford University School of Medicine, Stanford, CA, USA. Electronic address:
Distraction enterogenesis has been extensively studied as a potential treatment for short bowel syndrome, which is the most common subset of intestinal failure. Spring distraction uses an intraluminal axial mechanical force to stimulate the growth and elongation of the small intestine. The tissue close to the distracted intestinal segment may also experience signaling to grow.
View Article and Find Full Text PDFBiomechanics of small intestine during distraction enterogenesis with an intraluminal spring.
J Mech Behav Biomed Mater
January 2020
Department of Surgery, Division of Pediatric Surgery, Stanford University School of Medicine, Stanford, CA, 94305, USA; Department of Bioengineering, Stanford University School of Medicine, Stanford, CA, 94305, USA. Electronic address:
During recent years, distraction enterogenesis has been extensively studied as a treatment for short bowel syndrome, which is the most common cause of intestinal failure. Although different strategies such as parenteral nutrition and surgical lengthening have been used to manage the difficulties that patients with SBS deal with, these treatments are associated with high complication rates. Distraction enterogenesis uses mechanical force to increase the length and stimulate growth of the small intestine.
View Article and Find Full Text PDFIntestinal Electrical Stimulation to Increase the Rate of Peristalsis.
J Surg Res
April 2019
Division of Pediatric Surgery, Department of Surgery, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California; Department of Bioengineering, University of California Los Angeles, Los Angeles, California; Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California; Department of Bioengineering, Stanford University, Stanford, California. Electronic address:
Background: Pediatric gastrointestinal motility disorders are a large and broad group. Some of these disorders have been effectively treated with electrical stimulation. The goal of our present study is to determine whether the rate of intestinal peristalsis can be increased with electrical stimulation.
View Article and Find Full Text PDFIntestinal lengthening via multiple in-continuity springs.
J Pediatr Surg
January 2019
Division of Pediatric Surgery, Department of Surgery, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA; Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California, USA. Electronic address:
Background: Short bowel syndrome is a debilitating condition with few effective treatments. Spring-mediated distraction enterogenesis can be used to lengthen intestine. The purpose of this study is to determine whether multiple springs in series can safely increase the total amount of lengthening.
View Article and Find Full Text PDFDouble plication for spring-mediated in-continuity intestinal lengthening in a porcine model.
Surgery
February 2019
Department of Surgery, Division of Pediatric Surgery, Stanford University School of Medicine, Stanford, California. Electronic address:
Background: Short bowel syndrome is a condition with substantial morbidity and mortality, yet definitive therapies are lacking. Distraction enterogenesis uses mechanical force to "grow" new intestine. In this study, we examined whether intestinal plication can be used to safely achieve spring-mediated intestinal lengthening in a functioning segment of jejunum in its native position.
View Article and Find Full Text PDFSubcutaneous cefazolin to reduce surgical site infections in a porcine model.
J Surg Res
April 2018
Division of Pediatric Surgery, Department of Surgery, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California; Division of Pediatric Surgery, Department of Surgery, Stanford University, Stanford, California. Electronic address:
Background: Surgical site infections (SSIs) pose a significant health and financial burden. A key aspect of appropriate prophylaxis is the administration of antibiotics intravenously (IV). However, subcutaneous administration of antibiotics is not well described in the literature.
View Article and Find Full Text PDFDouble plication for spring-mediated intestinal lengthening of a defunctionalized Roux limb.
J Pediatr Surg
September 2018
Division of Pediatric Surgery, Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA; Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California, USA. Electronic address:
Background: Spring-mediated distraction enterogenesis has been shown to increase the length of an intestinal segment. The goal of this study is to use suture plication to confine a spring within an intestinal segment while maintaining luminal patency to the rest of the intestine.
Methods: Juvenile mini-Yucatan pigs underwent placement of nitinol springs within a defunctionalized Roux limb of jejunum.
Feasibility and scalability of spring parameters in distraction enterogenesis in a murine model.
J Surg Res
July 2017
Division of Pediatric Surgery, Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California; Division of Pediatric Surgery, Department of Surgery, School of Medicine, Stanford University, Stanford, California; Division of General Surgery, Department of Surgery, University of California, Los Angeles, Los Angeles, California. Electronic address:
Background: Distraction enterogenesis has been investigated as a novel treatment for short bowel syndrome (SBS). With variable intestinal sizes, it is critical to determine safe, translatable spring characteristics in differently sized animal models before clinical use. Nitinol springs have been shown to lengthen intestines in rats and pigs.
View Article and Find Full Text PDF