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Dural substitutes for spina bifida repair: past, present, and future. Childs Nerv Syst 2022; 38:873-891. [PMID: 35378616 PMCID: PMC9968456 DOI: 10.1007/s00381-022-05486-8] [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: 01/10/2022] [Accepted: 02/28/2022] [Indexed: 11/03/2022]
Abstract
PURPOSE The use of materials to facilitate dural closure during spina bifida (SB) repair has been a highly studied aspect of the surgical procedure. The overall objective of this review is to present key findings pertaining to the success of the materials used in clinical and pre-clinical studies. Additionally, this review aims to aid fetal surgeons as they prepare for open or fetoscopic prenatal SB repairs. METHODS Relevant publications centered on dural substitutes used during SB repair were identified. Important information from each article was extracted including year of publication, material class and sub-class, animal model used in pre-clinical studies, whether the repair was conducted pre-or postnatally, the bioactive agent delivered, and key findings from the study. RESULTS Out of 1,121 publications, 71 were selected for full review. We identified the investigation of 33 different patches where 20 and 63 publications studied synthetic and natural materials, respectively. From this library, 43.6% focused on clinical results, 36.6% focused on pre-clinical results, and 19.8% focused on tissue engineering approaches. Overall, the use of patches, irrespective of material, have shown to successfully protect the spinal cord and most have shown promising survival and neurological outcomes. CONCLUSION While most have shown significant promise as a therapeutic strategy in both clinical and pre-clinical studies, none of the patches developed so far are deemed perfect for SB repair. Therefore, there is an opportunity to develop new materials and strategies that aim to overcome these challenges and further improve the outcomes of SB patients.
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Theodorou CM, Jackson JE, Stokes SC, Pivetti CD, Kumar P, Paxton ZJ, Matsukuma KE, Yamashiro KJ, Reynaga L, Hyllen AA, de Lorimier AJ, Hassan M, Wang A, Farmer DL, Saadai P. Early investigations into improving bowel and bladder function in fetal ovine myelomeningocele repair. J Pediatr Surg 2022; 57:941-948. [PMID: 35093254 PMCID: PMC10372624 DOI: 10.1016/j.jpedsurg.2021.12.046] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 12/30/2021] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Fetal myelomeningocele (MMC) repair improves lower extremity motor function. We have previously demonstrated that augmentation of fetal MMC repair with placental mesenchymal stromal cells (PMSCs) seeded on extracellular matrix (PMSC-ECM) further improves motor function in the ovine model. However, little progress has been made in improving bowel and bladder function, with many patients suffering from neurogenic bowel and bladder. We hypothesized that fetal MMC repair with PMSC-ECM would also improve bowel and bladder function. METHODS MMC defects were surgically created in twelve ovine fetuses at median gestational age (GA) 73 days, followed by defect repair at GA101 with PMSC-ECM. Fetuses were delivered at GA141. Primary bladder function outcomes were voiding posture and void volumes. Primary bowel function outcome was anorectal manometry findings including resting anal pressure and presence of rectoanal inhibitory reflex (RAIR). Secondary outcomes were anorectal and bladder detrusor muscle thickness. PMSC-ECM lambs were compared to normal lambs (n = 3). RESULTS Eighty percent of PMSC-ECM lambs displayed normal voiding posture compared to 100% of normal lambs (p = 1). Void volumes were similar (PMSC-ECM 6.1 ml/kg vs. normal 8.8 ml/kg, p = 0.4). Resting mean anal pressures were similar between cohorts (27.0 mmHg PMSC-ECM vs. normal 23.5 mmHg, p = 0.57). RAIR was present in 3/5 PMSC-ECM lambs that underwent anorectal manometry and all normal lambs (p = 0.46). Thicknesses of anal sphincter complex, rectal wall muscles, and bladder detrusor muscles were similar between cohorts. CONCLUSION Ovine fetal MMC repair augmented with PMSC-ECM results in near-normal bowel and bladder function. Further work is needed to evaluate these outcomes in human patients.
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Affiliation(s)
- Christina M Theodorou
- Department of Surgery, Division of Pediatric General, Thoracic, and Fetal Surgery. University of California Davis Medical Center. Sacramento, CA, United States.
| | - Jordan E Jackson
- Department of Surgery, Division of Pediatric General, Thoracic, and Fetal Surgery. University of California Davis Medical Center. Sacramento, CA, United States
| | - Sarah C Stokes
- Department of Surgery, Division of Pediatric General, Thoracic, and Fetal Surgery. University of California Davis Medical Center. Sacramento, CA, United States
| | - Christopher D Pivetti
- Surgical Bioengineering Laboratory, University of California Davis Medical Center. Sacramento, CA, United States
| | - Priyadarsini Kumar
- Surgical Bioengineering Laboratory, University of California Davis Medical Center. Sacramento, CA, United States
| | - Zachary J Paxton
- Surgical Bioengineering Laboratory, University of California Davis Medical Center. Sacramento, CA, United States
| | - Karen E Matsukuma
- Department of Pathology and Laboratory Medicine, University of California Davis, Sacramento, CA, United States
| | - Kaeli J Yamashiro
- Department of Surgery, Division of Pediatric General, Thoracic, and Fetal Surgery. University of California Davis Medical Center. Sacramento, CA, United States
| | - Lizette Reynaga
- Surgical Bioengineering Laboratory, University of California Davis Medical Center. Sacramento, CA, United States
| | - Alicia A Hyllen
- Surgical Bioengineering Laboratory, University of California Davis Medical Center. Sacramento, CA, United States
| | - Arthur J de Lorimier
- Department of Pediatrics, Division of Gastroenterology. University of California Davis Medical Center. Sacramento, CA, United States
| | - Maheen Hassan
- Department of Pediatrics, Division of Gastroenterology. University of California Davis Medical Center. Sacramento, CA, United States
| | - Aijun Wang
- Surgical Bioengineering Laboratory, University of California Davis Medical Center. Sacramento, CA, United States
| | - Diana L Farmer
- Department of Surgery, Division of Pediatric General, Thoracic, and Fetal Surgery. University of California Davis Medical Center. Sacramento, CA, United States
| | - Payam Saadai
- Department of Surgery, Division of Pediatric General, Thoracic, and Fetal Surgery. University of California Davis Medical Center. Sacramento, CA, United States
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Theodorou CM, Stokes SC, Jackson JE, Pivetti CD, Kumar P, Yamashiro KJ, Paxton ZJ, Reynaga L, Hyllen AA, Wang A, Farmer DL. Efficacy of clinical-grade human placental mesenchymal stromal cells in fetal ovine myelomeningocele repair. J Pediatr Surg 2022; 57:753-758. [PMID: 34217509 PMCID: PMC9365331 DOI: 10.1016/j.jpedsurg.2021.05.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/11/2021] [Accepted: 05/31/2021] [Indexed: 11/17/2022]
Abstract
BACKGROUND While fetal repair of myelomeningocele (MMC) revolutionized management, many children are still unable to walk independently. Preclinical studies demonstrated that research-grade placental mesenchymal stromal cells (PMSCs) prevent paralysis in fetal ovine MMC, however this had not been replicated with clinical-grade cells that could be used in an upcoming human clinical trial. We tested clinical-grade PMSCs seeded on an extracellular matrix (PMSC-ECM) in the gold standard fetal ovine model of MMC. METHODS Thirty-five ovine fetuses underwent MMC defect creation at a median of 76 days gestational age, and defect repair at 101 days gestational age with application of clinical-grade PMSC-ECM (3 × 105 cells/cm2, n = 12 fetuses), research-grade PMSC-ECM (3 × 105 cells/cm2, three cell lines with n = 6 (Group 1), n = 6 (Group 2), and n = 3 (Group 3) fetuses, respectively) or ECM without PMSCs (n = 8 fetuses). Three normal lambs underwent no surgical interventions. The primary outcome was motor function measured by the Sheep Locomotor Rating scale (SLR, range 0: complete paralysis to 15: normal ambulation) at 24 h of life. Correlation of lumbar spine large neuron density with SLR was evaluated. RESULTS Clinical-grade PMSC-ECM lambs had significantly better motor function than ECM-only lambs (SLR 14.5 vs. 6.5, p = 0.04) and were similar to normal lambs (14.5 vs. 15, p = 0.2) and research-grade PMSC-ECM lambs (Group 1: 14.5 vs. 15, p = 0.63; Group 2: 14.5 vs. 14.5, p = 0.86; Group 3: 14.5 vs. 15, p = 0.50). Lumbar spine large neuron density was strongly correlated with motor function (r = 0.753, p<0.001). CONCLUSIONS Clinical-grade placental mesenchymal stromal cells seeded on an extracellular matrix rescued ambulation in a fetal ovine myelomeningocele model. Lumbar spine large neuron density correlated with motor function, suggesting a neuroprotective effect of the PMSC-ECM in prevention of paralysis. A first-in-human clinical trial of PMSCs in human fetal myelomeningocele repair is underway.
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Affiliation(s)
- Christina M. Theodorou
- Department of Surgery, Division of Pediatric General, Thoracic, and Fetal Surgery. University of California Davis Medical Center. Sacramento, CA,Surgical Bioengineering Laboratory, University of California Davis Medical Center. Sacramento, CA,Corresponding author information: Christina Theodorou, Department of Surgery, University of California Davis Medical Center, 2335 Stockton Blvd, Room 5107, Sacramento, CA 95817, , Phone: 916-453-2080
| | - Sarah C. Stokes
- Department of Surgery, Division of Pediatric General, Thoracic, and Fetal Surgery. University of California Davis Medical Center. Sacramento, CA,Surgical Bioengineering Laboratory, University of California Davis Medical Center. Sacramento, CA
| | - Jordan E. Jackson
- Department of Surgery, Division of Pediatric General, Thoracic, and Fetal Surgery. University of California Davis Medical Center. Sacramento, CA,Surgical Bioengineering Laboratory, University of California Davis Medical Center. Sacramento, CA
| | - Christopher D. Pivetti
- Surgical Bioengineering Laboratory, University of California Davis Medical Center. Sacramento, CA
| | - Priyadarsini Kumar
- Surgical Bioengineering Laboratory, University of California Davis Medical Center. Sacramento, CA
| | - Kaeli J. Yamashiro
- Department of Surgery, Division of Pediatric General, Thoracic, and Fetal Surgery. University of California Davis Medical Center. Sacramento, CA,Surgical Bioengineering Laboratory, University of California Davis Medical Center. Sacramento, CA
| | - Zachary J. Paxton
- Surgical Bioengineering Laboratory, University of California Davis Medical Center. Sacramento, CA
| | - Lizette Reynaga
- Surgical Bioengineering Laboratory, University of California Davis Medical Center. Sacramento, CA
| | - Alicia A. Hyllen
- Surgical Bioengineering Laboratory, University of California Davis Medical Center. Sacramento, CA
| | - Aijun Wang
- Department of Surgery, Division of Pediatric General, Thoracic, and Fetal Surgery. University of California Davis Medical Center. Sacramento, CA,Surgical Bioengineering Laboratory, University of California Davis Medical Center. Sacramento, CA
| | - Diana L. Farmer
- Department of Surgery, Division of Pediatric General, Thoracic, and Fetal Surgery. University of California Davis Medical Center. Sacramento, CA,Surgical Bioengineering Laboratory, University of California Davis Medical Center. Sacramento, CA
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Stokes SC, Theodorou CM, Jackson JE, Pivetti C, Kumar P, Yamashiro KJ, Paxton ZJ, Reynaga L, Hyllen A, Wang A, Farmer DL. Long-term safety evaluation of placental mesenchymal stromal cells for in utero repair of myelomeningocele in a novel ovine model. J Pediatr Surg 2022; 57:18-25. [PMID: 34657738 PMCID: PMC9415987 DOI: 10.1016/j.jpedsurg.2021.09.021] [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: 08/23/2021] [Accepted: 09/08/2021] [Indexed: 01/03/2023]
Abstract
PURPOSE Augmentation of in utero myelomeningocele repair with human placental mesenchymal stromal cells seeded onto extracellular matrix (PMSC-ECM) improves motor outcomes in an ovine myelomeningocele model. This study evaluated the safety of PMSC-ECM application directly onto the fetal spinal cord in preparation for a clinical trial. METHODS Laminectomy of L5-L6 with PMSC-ECM placement directly onto the spinal cord was performed in five fetal lambs at gestational age (GA) 100-106 days. Lambs and ewes were monitored for three months following delivery. Lambs underwent magnetic resonance imaging (MRI) of the brain and spine at birth and at three months. All organs from lambs and uteri from ewes underwent histologic evaluation. Lamb spinal cords and brains and ewe placentas were evaluated for persistence of PMSCs by polymerase chain reaction for presence of human DNA. RESULTS MRIs demonstrated no evidence of abnormal tissue growth or spinal cord tethering. Histological analysis demonstrated no evidence of abnormal tissue growth or treatment related adverse effects. No human DNA was identified in evaluated tissues. CONCLUSION There was no evidence of abnormal tissue growth or PMSC persistence at three months following in utero application of PMSC-ECM to the spinal cord. This supports proceeding with clinical trials of PMSC-ECM for in utero myelomeningocele repair. LEVEL OF EVIDENCE N/A TYPE OF STUDY: Basic science.
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Affiliation(s)
- Sarah C Stokes
- Division of Pediatric General, Thoracic and Fetal Surgery, Department of Surgery, University of California Davis Medical Center, 2335 Stockton Blvd, Room 5107, Sacramento, CA 95817, USA.
| | - Christina M Theodorou
- Division of Pediatric General, Thoracic, and Fetal Surgery, Department of Surgery, University of California Davis Medical Center, Sacramento, CA 95817, USA
| | - Jordan E Jackson
- Division of Pediatric General, Thoracic, and Fetal Surgery, Department of Surgery, University of California Davis Medical Center, Sacramento, CA 95817, USA
| | - Christopher Pivetti
- Surgical Bioengineering Laboratory, University of California Davis, Sacramento, CA 95817, USA
| | - Priyadarsini Kumar
- Surgical Bioengineering Laboratory, University of California Davis, Sacramento, CA 95817, USA
| | - Kaeli J Yamashiro
- Division of Pediatric General, Thoracic, and Fetal Surgery, Department of Surgery, University of California Davis Medical Center, Sacramento, CA 95817, USA
| | - Zachary J Paxton
- Surgical Bioengineering Laboratory, University of California Davis, Sacramento, CA 95817, USA
| | - Lizette Reynaga
- Surgical Bioengineering Laboratory, University of California Davis, Sacramento, CA 95817, USA
| | - Alicia Hyllen
- Surgical Bioengineering Laboratory, University of California Davis, Sacramento, CA 95817, USA
| | - Aijun Wang
- Surgical Bioengineering Laboratory, University of California Davis, Sacramento, CA 95817, USA.,Shriners Hospital for Children Northern California, 3425 Stockton Blvd, Sacramento, CA 95817, USA
| | - Diana L Farmer
- Division of Pediatric General, Thoracic, and Fetal Surgery, Department of Surgery, University of California Davis Medical Center, Sacramento, CA 95817, USA.,Surgical Bioengineering Laboratory, University of California Davis, Sacramento, CA 95817, USA.,Shriners Hospital for Children Northern California, 3425 Stockton Blvd, Sacramento, CA 95817, USA
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Jackson JE, Pivetti C, Stokes SC, Theodorou CM, Kumar P, Paxton ZJ, Hyllen A, Reynaga L, Wang A, Farmer DL. Placental Mesenchymal Stromal Cells: Preclinical Safety Evaluation for Fetal Myelomeningocele Repair. J Surg Res 2021; 267:660-668. [PMID: 34273796 PMCID: PMC9365330 DOI: 10.1016/j.jss.2021.06.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 06/01/2021] [Accepted: 06/09/2021] [Indexed: 12/15/2022]
Abstract
BACKGROUND Myelomeningocele (MMC) is the congenital failure of neural tube closure in utero, for which the standard of care is prenatal surgical repair. We developed clinical-grade placental mesenchymal stromal cells seeded on a dural extracellular matrix (PMSC-ECM), which have been shown to improve motor outcomes in preclinical ovine models. To evaluate the long-term safety of this product prior to use in a clinical trial, we conducted safety testing in a murine model. METHODS Clinical grade PMSCs obtained from donor human placentas were seeded onto a 6 mm diameter ECM at a density of 3 × 105 cells/cm2. Immunodeficient mice were randomized to receive either an ECM only or PMSC-ECM administered into a subcutaneous pocket. Mice were monitored for tumor formation until two study endpoints: 4 wk and 6 mo. Pathology and histology on all tissues was performed to evaluate for tumors. Quantitative polymerase chain reaction (qPCR) was performed to evaluate for the presence of human DNA, which would indicate persistence of PMSCs. RESULTS Fifty-four mice were included; 13 received ECM only and 14 received PMSC-ECM in both the 4-wk and 6-mo groups. No mice had gross or microscopic evidence of tumor development. A nodular focus of mature fibrous connective tissue was identified at the subcutaneous implantation pocket in the majority of mice with no significant difference between ECM only and PMSC-ECM groups (P = 0.32 at 4 wk, P > 0.99 at 6 mo). Additionally, no human DNA was detected by qPCR in any mice at either time point. CONCLUSIONS Subcutaneous implantation of the PMSC-ECM product did not result in tumor formation and we found no evidence that PMSCs persisted. These results support the safety of the PMSC-ECM product for use in a Phase 1/2a human clinical trial evaluating fetal MMC repair augmented with PMSC-ECM.
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Affiliation(s)
- Jordan E Jackson
- Division of Pediatric General, Thoracic and Fetal Surgery, University of California Davis Medical Center, Sacramento, California; Department of Surgery, University of California Davis, Sacramento, California.
| | - Christopher Pivetti
- Department of Surgery, University of California Davis, Sacramento, California
| | - Sarah C Stokes
- Division of Pediatric General, Thoracic and Fetal Surgery, University of California Davis Medical Center, Sacramento, California; Department of Surgery, University of California Davis, Sacramento, California
| | - Christina M Theodorou
- Division of Pediatric General, Thoracic and Fetal Surgery, University of California Davis Medical Center, Sacramento, California; Department of Surgery, University of California Davis, Sacramento, California
| | - Priyadarsini Kumar
- Department of Surgery, University of California Davis, Sacramento, California
| | - Zachary J Paxton
- Department of Surgery, University of California Davis, Sacramento, California
| | - Alicia Hyllen
- Department of Surgery, University of California Davis, Sacramento, California
| | - Lizette Reynaga
- Department of Surgery, University of California Davis, Sacramento, California
| | - Aijun Wang
- Department of Surgery, University of California Davis, Sacramento, California
| | - Diana L Farmer
- Division of Pediatric General, Thoracic and Fetal Surgery, University of California Davis Medical Center, Sacramento, California; Department of Surgery, University of California Davis, Sacramento, California
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Stokes SC, Jackson JE, Theodorou CM, Pivetti CD, Kumar P, Yamashiro KJ, Wang A, Farmer DL. A Novel Model of Fetal Spinal Cord Exposure Allowing for Long-Term Postnatal Survival. Fetal Diagn Ther 2021; 48:472-478. [PMID: 34111873 DOI: 10.1159/000516542] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 04/07/2021] [Indexed: 11/19/2022]
Abstract
BACKGROUND The inherent morbidity associated with fetal ovine models of myelomeningocele (MMC) has created challenges for long-term survival of lambs. We aimed to develop a fetal ovine surgical spinal exposure model which could be used to evaluate long-term safety after direct spinal cord application of novel therapeutics for augmentation of in utero MMC repair. METHODS At gestational age (GA) 100-106, fetal lambs underwent surgical intervention. Laminectomy of L5-L6 was performed, dura was removed, and an experimental product was directly applied to the spinal cord. Paraspinal muscles and skin were closed and the fetus was returned to the uterus. Lambs were delivered via cesarean section at GA 140-142. Lambs were survived for 3 months with regular evaluation of motor function by the sheep locomotor rating scale. Spinal angulation was evaluated by magnetic resonance imaging at 2 weeks and 3 months. RESULTS Five fetal surgical intervention lambs and 6 control lambs who did not undergo surgical intervention were included. All lambs survived to the study endpoint of 3 months. No lambs had motor function abnormalities or increased spinal angulation. CONCLUSION This model allows for long-term survival after fetal spinal cord exposure with product application directly onto the spinal cord.
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Affiliation(s)
- Sarah C Stokes
- Department of Surgery, University of California-Davis, Sacramento, California, USA
| | - Jordan E Jackson
- Department of Surgery, University of California-Davis, Sacramento, California, USA
| | | | - Christopher D Pivetti
- Department of Biomedical Engineering, University of California-Davis, Davis, California, USA
| | - Priyadarsini Kumar
- Department of Biomedical Engineering, University of California-Davis, Davis, California, USA
| | - Kaeli J Yamashiro
- Department of Surgery, University of California-Davis, Sacramento, California, USA
| | - Aijun Wang
- Department of Surgery, University of California-Davis, Sacramento, California, USA.,Department of Biomedical Engineering, University of California-Davis, Davis, California, USA
| | - Diana L Farmer
- Department of Surgery, University of California-Davis, Sacramento, California, USA.,Shriners Hospital for Children Northern California, Sacramento, California, USA
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