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Kiseleva EB, Sovetsky AA, Ryabkov MG, Gubarkova EV, Plekhanov AA, Bederina EL, Potapov AL, Bogomolova AY, Zaitsev VY, Gladkova ND. Detecting emergence of ruptures in individual layers of the stretched intestinal wall using optical coherence elastography: A pilot study. JOURNAL OF BIOPHOTONICS 2024:e202400086. [PMID: 38923316 DOI: 10.1002/jbio.202400086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 04/26/2024] [Accepted: 05/24/2024] [Indexed: 06/28/2024]
Abstract
We report a new application of compression optical coherence elastography (C-OCE) to monitor the emergence of ruptures in individual layers of longitudinally stretched small-intestine walls using tissue samples (n = 36) from nine minipigs. Before stretching, C-OCE successfully estimated stiffness for each intestine-wall layer: longitudinal muscular layer with serosa, circumferential muscular layer, submucosa and mucosa. In stretched samples, C-OCE clearly visualized initial stiffening in both muscular layers. By 25% elongation, a sharp stiffness decrease for the longitudinal muscular layer, indicated emergence of tears in all samples. With further stretching, for most samples, ruptures emerged in the circumferential muscular layer and submucosa, while mucosa remained undamaged. Histology confirmed the OCE-revealed damaging and absence of tissue damage for ~15% elongation. Thus, C-OCE has demonstrated a high potential for determining the safety tissue-stretching threshold which afterward may be used intraoperatively to prevent rupture risk in intestinal tissues stretched during various diagnostic/therapeutic procedures.
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Affiliation(s)
- Elena B Kiseleva
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Alexander A Sovetsky
- Nonlinear Geophysical Processes Department, A.V. Gaponov-Grekhov Institute of Applied Physics of the Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Maksim G Ryabkov
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Ekaterina V Gubarkova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Anton A Plekhanov
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Evgeniya L Bederina
- University Clinic, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Arseniy L Potapov
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Alexandra Y Bogomolova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Vladimir Y Zaitsev
- Nonlinear Geophysical Processes Department, A.V. Gaponov-Grekhov Institute of Applied Physics of the Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Natalia D Gladkova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
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Salimi-Jazi F, Thomas AL, Rafeeqi TA, Wood LSY, Portelli K, Dunn JCY. Stem cell activation during distraction enterogenesis in the murine colon. Pediatr Surg Int 2023; 39:172. [PMID: 37031428 DOI: 10.1007/s00383-023-05455-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/03/2023] [Indexed: 04/10/2023]
Abstract
PURPOSE Short bowel syndrome (SBS) is a devastating disease. We have proposed spring-mediated distraction enterogenesis for intestinal lengthening. Colonic lengthening is a potential treatment option for SBS to enhance fluid absorption capacity. We hypothesized that intraluminal spring-mediated colonic lengthening is associated with stem cell proliferation. METHODS C57BL/6 mice underwent placement of a gelatin-encapsulated compressed or uncompressed nitinol spring in a cecal segment. Animals were given clear liquid diet until postoperative day (POD) 7, followed by regular diet until POD 14. Cecal lengths were measured at euthanasia, and tissue was formalin fixed for histological processing. For Lgr5-GFP mice, immunohistochemistry against GFP was performed to localize Lgr5+ cells within crypts. RESULTS Significant cecal lengthening with compressed springs and shortening with uncompressed springs were observed on POD 7 and 14. Mucosa of the compressed spring group was significantly thicker on POD 14. The density of Lgr5+ cells within the crypts in the compressed spring groups was higher than that in the uncompressed spring groups on both POD 7 and 14. CONCLUSION Expandable springs can be used to lengthen the colon in the mouse model. Colonic lengthening was associated with gradual mucosal thickening and correlated with an increased density of stem cells within the crypts.
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Affiliation(s)
- Fereshteh Salimi-Jazi
- Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, 453 Quarry Road, MC 5733, Palo Alto, CA, 94304, USA
| | - Anne-Laure Thomas
- Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, 453 Quarry Road, MC 5733, Palo Alto, CA, 94304, USA
| | - Talha A Rafeeqi
- Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, 453 Quarry Road, MC 5733, Palo Alto, CA, 94304, USA
| | - Lauren S Y Wood
- Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, 453 Quarry Road, MC 5733, Palo Alto, CA, 94304, USA
| | - Katherine Portelli
- Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, 453 Quarry Road, MC 5733, Palo Alto, CA, 94304, USA
| | - James C Y Dunn
- Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, 453 Quarry Road, MC 5733, Palo Alto, CA, 94304, USA.
- Department of Bioengineering, Stanford University, Stanford, CA, USA.
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Long-term safety of intraluminal spring-mediated bowel lengthening. J Pediatr Surg 2023; 58:89-93. [PMID: 36280466 DOI: 10.1016/j.jpedsurg.2022.09.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 09/16/2022] [Indexed: 01/12/2023]
Abstract
PURPOSE The purpose of the study is to examine the long-term safety of an endoluminal bowel lengthening device prior to its use in the first human trial. In addition, device performance and natural passage will be evaluated. METHODS Endoluminal lengthening springs were surgically placed into the jejunum of Yucatan minipigs using the Eclipse XL1 device. A matching internal control segment of jejunum was marked at the time of operation. Weekly weights and fluoroscopic studies were obtained to evaluate spring deployment and position until devices passed. Animals were euthanized at 28, 60, 90, and 180 days. At necropsy, length measurements were recorded, and histopathologic analysis was performed. RESULTS There were no bowel obstructions or overt perforations attributable to the device. All surviving animals gained weight and were clinically thriving. All devices passed out of the rectum by 180 days. Bowel lengthening was seen in all experimental segments, and minimal fibrosis was observed by 180 days. CONCLUSION Jejunal lengthening persisted after device had passed through the intestinal tract after 180 days. Early histopathologic changes of the jejunum during distraction enterogenesis normalized over time.
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Rafeeqi TA, Diyaolu M, Thomas AL, Salimi-Jazi F, Wood LSY, Dunn JCY. Generation of Porcine Ileum Through Spring-Mediated Mechanical Distraction. J Surg Res 2022; 280:371-378. [PMID: 36037614 DOI: 10.1016/j.jss.2022.07.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 07/12/2022] [Accepted: 07/28/2022] [Indexed: 11/27/2022]
Abstract
INTRODUCTION Short bowel syndrome is a devastating gastrointestinal disorder in which decreased bowel length results in inadequate absorption causing nutritional deficiencies. Current treatment options are accompanied by significant morbidity. We have proposed spring-mediated distraction enterogenesis as a method to lengthen bowel with success seen in porcine jejunum. We hypothesize that spring-mediated distraction enterogenesis can be demonstrated in porcine ileum with preservation of ileal structure and function. MATERIALS AND METHODS Laparotomy was performed on juvenile female mini-Yucatan pigs and a gelatin-encapsulated compressed nitinol spring was inserted into the ileal lumen and affixed proximally and distally. A control segment distal to the spring segment was marked with sutures. Postoperatively, pigs were placed on a liquid diet and euthanized on postoperative day 7. Spring and control segments were measured and processed for immunohistochemistry to evaluate for the presence of vitamin B12-intrinsic factor cotransporter, chromogranin A-producing cells, and 5-HT producing cells. RESULTS All seven pigs survived to postoperative day 7 with no adverse effects. On average, pigs gained 84.3 ± 66.4 g/d. Spring segments lengthened 1.5 ± 0.7 cm with a relative lengthening by 128% ± 56%, which was statistically significant when compared to control (P < 0.01). The average density of chromogranin-A cells in control compared to spring segments was not significantly changed (2.9 ± 1.1 cells/mm versus 3.2 ± 1.2 cells/mm, P = 0.17). Both vitamin B12-intrinsic factor cotransporter and 5-HT producing cells were present in both control and lengthened ileum. CONCLUSIONS Intraluminal nitinol springs significantly lengthened porcine ileum. The increase in density of enteroendocrine cells may indicate enhanced endocrine function of the lengthened ileum.
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Affiliation(s)
- Talha A Rafeeqi
- Division of Pediatric Surgery, Stanford University, Stanford, California
| | - Modupeola Diyaolu
- Division of Pediatric Surgery, Stanford University, Stanford, California
| | - Anne-Laure Thomas
- Division of Pediatric Surgery, Stanford University, Stanford, California
| | | | - Lauren S Y Wood
- Division of Pediatric Surgery, Stanford University, Stanford, California
| | - James C Y Dunn
- Division of Pediatric Surgery, Stanford University, Stanford, California; Department of Bioengineering, Stanford University, Stanford, California.
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Salimi-Jazi F, Thomas AL, Rafeeqi T, Diyaolu M, Wood LSY, Dunn JCY. The effect of spring diameter on porcine ileal distraction enterogenesis. Pediatr Surg Int 2022; 39:19. [PMID: 36449179 DOI: 10.1007/s00383-022-05300-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/11/2022] [Indexed: 12/03/2022]
Abstract
PURPOSE Spring-mediated distraction enterogenesis has proven to be successful for intestinal lengthening. We aimed to evaluate the effect of spring diameter mismatch on intestinal adaptation. METHODS Juvenile mini-Yucatan pigs underwent placement of compressed nitinol springs with diameter of 10, 11, or 12 mm into the ileal lumen. Pigs were euthanized on postoperative day 7. The lengths, histology, total area of blood vessels, and enteric ganglia were evaluated. RESULTS All spring groups exhibited significant ileal lengthening. Across the different diameters, spring-expanded segments were similar in terms of ileal lengthening, crypt height, muscular thickness, blood vessels, and enteric ganglia area. CONCLUSION Spring-mediated distraction enterogenesis is successful in the porcine ileum. A smaller diameter spring is as effective as a larger diameter spring in lengthening the ileum. Springs of varying diameters result in comparable structural changes in the ileum.
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Affiliation(s)
- Fereshteh Salimi-Jazi
- Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Anne-Laure Thomas
- Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Talha Rafeeqi
- Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Modupeola Diyaolu
- Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Lauren S Y Wood
- Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - James C Y Dunn
- Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA.
- Department of Bioengineering, Stanford University, Stanford, CA, USA.
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Internal plication for spring confinement to lengthen intestine in a porcine model. PLoS One 2022; 17:e0274612. [PMID: 36107915 PMCID: PMC9477332 DOI: 10.1371/journal.pone.0274612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 09/01/2022] [Indexed: 11/18/2022] Open
Abstract
Background Short bowel syndrome and its resultant nutritional deficiencies are the most common cause of intestinal failure. Significant intestinal lengthening using intraluminal springs is feasible in porcine models using an external plication technique. We hypothesize that an internal plication technique will yield significant intestinal lengthening, which may lead to future endoscopic spring placement. Methods Uncompressed springs measuring 7.5 cm with a diameter of 1.0 cm were compressed to 2.0 cm. A gelatin-encapsulated compressed nitinol spring was inserted into the jejunal lumen of juvenile pigs and held in place with endoluminal sutures just proximal and distal to the spring-containing segment. A control segment distal to the spring was marked. Pigs were euthanized on postoperative day 7. Spring and control segments were collected for analyses. Results There was an average lengthening by 72% of the spring segment compared to the control segment. Two out of 7 springs stayed within both sets of plications and doubled in length. Histology showed normal mucosal integrity of the spring segment and plicated areas with similar muscular thickness but increased crypt depth and villus length compared to the control segment. Conclusion Internal plication resulted in significant bowel lengthening. Five springs had slipped through proximal, distal or both sets of plications, resulting in less lengthening than those that remained fixed. A more consistent methodology for endoluminal suturing is needed to produce more lengthening.
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Liang W, Zhao E, Li G, Bi H, Zhao Z. Suture Cells in a Mechanical Stretching Niche: Critical Contributors to Trans-sutural Distraction Osteogenesis. Calcif Tissue Int 2022; 110:285-293. [PMID: 34802070 DOI: 10.1007/s00223-021-00927-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 10/25/2021] [Indexed: 02/06/2023]
Abstract
Trans-sutural distraction osteogenesis has been proposed as an alternative technique of craniofacial remodelling surgery for craniosynostosis correction. Many studies have defined the contribution of a series of biological events to distraction osteogenesis, such as changes in gene expression, changes in suture cell behaviour and changes in suture collagen fibre characteristics. However, few studies have elucidated the systematic molecular and cellular mechanisms of trans-sutural distraction osteogenesis, and no study has highlighted the contribution of cell-cell or cell-matrix interactions with respect to the whole expansion process to date. Therefore, it is difficult to translate largely primary mechanistic insights into clinical applications and optimize the clinical outcome of trans-sutural distraction osteogenesis. In this review, we carefully summarize in detail the literature related to the effects of mechanical stretching on osteoblasts, endothelial cells, fibroblasts, immune cells (macrophages and T cells), mesenchymal stem cells and collagen fibres in sutures during the distraction osteogenesis process. We also briefly review the contribution of cell-cell or cell-matrix interactions to bone regeneration at the osteogenic suture front from a comprehensive viewpoint.
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Affiliation(s)
- Wei Liang
- Department of Plastic Surgery, Peking University Third Hospital, Beijing, 100191, China
| | - Enzhe Zhao
- Department of Orthopedics, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Shanxi Medical University, Taiyuan, China
| | - Guan Li
- Department of Plastic Surgery, Peking University Third Hospital, Beijing, 100191, China
| | - Hongsen Bi
- Department of Plastic Surgery, Peking University Third Hospital, Beijing, 100191, China.
| | - Zhenmin Zhao
- Department of Plastic Surgery, Peking University Third Hospital, Beijing, 100191, China.
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Wood LS, Hosseini HS, Diyaolu M, Thomas AL, Taylor JS, Dunn JC. Mechanical lengthening of porcine small intestine with decreased forces. J Pediatr Surg 2021; 56:1192-1198. [PMID: 33836847 DOI: 10.1016/j.jpedsurg.2021.03.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 03/12/2021] [Indexed: 11/26/2022]
Abstract
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. Given our previous success lengthening intestinal segments using springs with spring constant ~7 N/m that exerts 0.46 N or higher, we sought to determine the minimal force needed to lengthen porcine small intestinal segments, and to explore effects on intestine over time. METHODS Juvenile Yucatan pigs underwent laparotomy with enterotomy to introduce nitinol springs intraluminally (n = 21 springs). Bowel segments (control, spring-distracted) were retrieved on post-operative day (POD) 7 and 14, and lengths measured. Thickness of cross-sectional intestinal layers were measured using H&E, and submucosal collagen fiber orientation measured using trichrome stained sections. RESULTS all pigs survived to POD7 and 14. Spring constants of at least 2 N/m exerting a minimum force of 0.10 N significantly lengthened intestinal segments (p <0.0001). The stronger the spring force, the greater the induced thickness of various intestinal layers at POD7 and 14. Collagen fiber orientation was also more disordered because of stronger springs. CONCLUSION a spring constant of approximately 2 N/m exerting 0.10 N and greater significantly lengthens intestinal segments and stimulates intestinal structural changes at POD7 and 14. This suggests a decreased force is capable of inducing spring-mediated distraction enterogenesis.
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Affiliation(s)
- Lauren Sy Wood
- Division of Pediatric Surgery, Stanford University School of Medicine, 453 Quarry Road, MC 5733, Stanford, CA 94304, United States
| | - Hadi S Hosseini
- Division of Pediatric Surgery, Stanford University School of Medicine, 453 Quarry Road, MC 5733, Stanford, CA 94304, United States
| | - Modupeola Diyaolu
- Division of Pediatric Surgery, Stanford University School of Medicine, 453 Quarry Road, MC 5733, Stanford, CA 94304, United States
| | - Anne-Laure Thomas
- Division of Pediatric Surgery, Stanford University School of Medicine, 453 Quarry Road, MC 5733, Stanford, CA 94304, United States
| | - Jordan S Taylor
- Division of Pediatric Surgery, Stanford University School of Medicine, 453 Quarry Road, MC 5733, Stanford, CA 94304, United States
| | - James Cy Dunn
- Division of Pediatric Surgery, Stanford University School of Medicine, 453 Quarry Road, MC 5733, Stanford, CA 94304, United States.
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Ghorbanniahassankiadeh A, Marks DS, LaDisa JF. Correlation of Computational Instantaneous Wave-Free Ratio With Fractional Flow Reserve for Intermediate Multivessel Coronary Disease. J Biomech Eng 2021; 143:051011. [PMID: 33454732 DOI: 10.1115/1.4049746] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Indexed: 01/14/2023]
Abstract
This study computationally assesses the accuracy of an instantaneous wave-free ratio (iFR) threshold range compared to standard modalities such as fractional flow reserve (FFR) and coronary flow reserve (CFR) for multiple intermediate lesions near the left main (LM) coronary bifurcation. iFR is an adenosine-independent index encouraged for assessment of coronary artery disease (CAD), but different thresholds are debated. This becomes particularly challenging in cases of multivessel disease when sensitivity to downstream lesions is unclear. Idealized LM coronary arteries with 34 different intermediate stenoses were created and categorized (Medina) as single and multiple lesion groups. Computational fluid dynamics modeling was performed with physiologic boundary conditions using an open-source software (simvascular1) to solve the time-dependent Navier-Stokes equations. A strong linear relationship between iFR and FFR was observed among studied models, indicating computational iFR values of 0.92 and 0.93 are statistically equivalent to an FFR of 0.80 in single and multiple lesion groups, respectively. At the clinical FFR value (i.e., 0.8), a triple-lesion group had smaller CFR compared to the single and double lesion groups (e.g., triple = 3.077 versus single = 3.133 and double = 3.132). In general, the effect of additional intermediate downstream lesions (minimum lumen area > 3 mm2) was not statistically significant for iFR and CFR. A computational iFR of 0.92 best predicts an FFR of 0.80 and may be recommended as threshold criteria for computational assessment of LM stenosis following additional validation using patient-specific models.
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Affiliation(s)
- Arash Ghorbanniahassankiadeh
- Department of Biomedical Engineering, Medical College of Wisconsin and Marquette University, 8701 W Watertown Plank Road, Milwaukee, WI 53226
| | - David S Marks
- Division of Cardiovascular Medicine, Department of Medicine, Medical College of Wisconsin, 8701 W Watertown Plank Road, Milwaukee, WI 53226
| | - John F LaDisa
- Department of Biomedical Engineering, Medical College of Wisconsin and Marquette University, 8701 W Watertown Plank Road, Milwaukee, WI 53226; Department of Physiology, Medical College of Wisconsin, 8701 W Watertown Plank Road, Milwaukee, WI 53226; Department of Medicine, Medical College of Wisconsin, 8701 W Watertown Plank Road, Milwaukee, WI 53226
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Diyaolu M, Thomas AL, Wood LS, Taylor J, Dunn JC. Mesenteric neovascularization during spring-mediated intestinal lengthening. J Pediatr Surg 2021; 56:5-10. [PMID: 33143878 DOI: 10.1016/j.jpedsurg.2020.09.042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 09/22/2020] [Indexed: 12/20/2022]
Abstract
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. METHODS Female juvenile Yucatan pigs underwent laparotomy and insertion of gelatin-encapsulated compressed nitinol springs, held in place with plication sutures, into the jejunum. At surgery and sacrifice, macroscopic mesenteric blood vessels were counted between the plication sites. Histologic samples of the mesentery were obtained to evaluate microscopic vasculature. RESULTS A statistically significant increase in macroscopic mesenteric blood vessels was seen after intestinal lengthening (before: 1.9 ± 0.7 vessels, after: 4.7 ± 1.2 vessels, p = 0.001). A statistical significance is also seen in the density of arterioles (control: 3.0 ± 3.0 vessels/mm, spring: 7.0 ± 9.0 vessels/mm, p = 0.01) and venules (control: 4.0 ± 3.0 vessels/mm, spring: 8.0 ± 8.0 vessels/mm, p = 0.003). CONCLUSION Intestinal segments lengthened by intraluminal springs demonstrated total greater number of macroscopic vessels and microscopic blood vessels per length of mesentery as compared to control. This suggests local changes within the mesentery to recruit blood supply to growing intestine. LEVEL OF EVIDENCE N/A TYPE OF STUDY: Treatment study.
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Affiliation(s)
- Modupeola Diyaolu
- Department of Surgery, Division of Pediatric Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Anne-Laure Thomas
- Department of Surgery, Division of Pediatric Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Lauren Sy Wood
- Department of Surgery, Division of Pediatric Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Jordan Taylor
- Department of Surgery, Division of Pediatric Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - James Cy Dunn
- Department of Surgery, Division of Pediatric Surgery, Stanford University School of Medicine, Stanford, CA, USA.
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Biomechanical Force Prediction for Lengthening of Small Intestine during Distraction Enterogenesis. Bioengineering (Basel) 2020; 7:bioengineering7040140. [PMID: 33171760 PMCID: PMC7711478 DOI: 10.3390/bioengineering7040140] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/04/2020] [Accepted: 10/28/2020] [Indexed: 11/16/2022] Open
Abstract
Distraction enterogenesis has been extensively studied as a potential treatment for short bowel syndrome, which is the most common form of intestinal failure. Different strategies including parenteral nutrition and surgical lengthening to manage patients with short bowel syndrome are associated with high complication rates. More recently, self-expanding springs have been used to lengthen the small intestine using an intraluminal axial mechanical force, where this biomechanical force stimulates the growth and elongation of the small intestine. Differences in physical characteristics of patients with short bowel syndrome would require a different mechanical force—this is crucial in order to achieve an efficient and safe lengthening outcome. In this study, we aimed to predict the required mechanical force for each potential intestinal size. Based on our previous experimental observations and computational findings, we integrated our experimental measurements of patient biometrics along with mechanical characterization of the soft tissue into our numerical simulations to develop a series of computational models. These computational models can predict the required mechanical force for any potential patient where this can be advantageous in predicting an individual’s tissue response to spring-mediated distraction enterogenesis and can be used toward a safe delivery of the mechanical force.
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