Porcine Small Intestinal Submucosa Research Articles

Use of Anal Fistula Plug for Treatment of Fistula-in-ano: A Novel Technique?

Abstract Background: Fistula-in-ano is a chronic phase of anorectal suppuration characterized by purulent discharge. The conventional gold standard fistulotomy opens the entire track to heal with secondary intention. Anal fistula plug (AFP) is one of the newer modalities where the track is debrided from within and plugged with a biodegradable material made of porcine small intestinal submucosa. Materials and Methods: A total of 100 patients were enrolled in a randomized prospective study into two groups: conventional fistulotomy (CF) group and AFP group with 50 patients in each arm. The demography and surgical outcomes were assessed for postoperative pain, discharge and recovery, and failure. Results: All 100 patients included in the study had a history of anorectal suppuration which led to the residual anal fistula. Postoperative pain and analgesic requirements were equal in the two groups. The recovery period and return to work were shorter in the AFP group, and this difference was statistically significant. The success rate was 100% in the CF group as compared to 76% in the AFP group. There was no significant complication, failure, or recurrence in the CF group as against allergy (1), extrusion of plug (2), and failure/recurrence (9) in the AFP group. Conclusion: Our study shows that the application of bioprosthetic plugs may be an alternative option in a select group of patients. AFP has also shown to have a faster recovery with less morbidity and comparable success rates.

Interlayer repair with porcine small intestinal submucosa versus internal repair with tragus cartilage in endoscopic tympanoplasty

ObjectiveEndoscopic tympanoplasty includes various surgical methods, including internal repair, interlayer repair, and external overlay. This technique requires autologous materials, allografts, and xenografts, which are used to repair tympanic membrane (TM) perforation. To obtain good results, appropriate surgical methods and repair materials should be selected. In this study, we aimed to assess the efficacy of repairing refractory TM perforations in the porcine small intestinal submucosa (SIS) during transcanal endoscopic type I tympanoplasty, focusing on wound healing rates and hearing improvement. MethodA retrospective chart review was performed on patients who underwent TM perforation repair with porcine SIS and tragus cartilage between January 2022 and September 2022 at Sir Run Run Shaw Hospital, Zhejiang University School of Medicine (Hangzhou, China). We considered perforation size, tympanic status, pre- and postoperative symptoms, follow-up data, wound healing rates, and hearing improvement. ResultsOf the 115 patients included in the study, 56 underwent interlayer repair with porcine SIS of the TM, and 59 patients underwent internal repair with tragus cartilage. No significant difference was found between the two groups at baseline in terms of age, sex, disease course, perforation side, tympanic status, underlying disease, or preoperative infection. The total postoperative effective rate of interlayer implantation with porcine SIS was 91.07% (51 patients), and that of internal implantation with tragus cartilage was 88.14% (52 patients). No significant difference was found in terms of the graft success rate between the two surgical methods (p = 0.887). Postoperative pure tone auditory (PTA) and air-bone gap (ABG) density significantly increased in both groups compared with before surgery (p < 0.05). However, the postoperative PTA and ABG density were not significantly different three months post-surgery between the two groups (p > 0.05). Compared to those in the internal implantation group, the patients in the interlayer group had a shorter operation duration (51.36 ± 6.76 min vs. 59.71 ± 7.45 min, t = 6.298, p < 0.001) and less blood loss (11.91 ± 2.61 mL vs. 15.27 ± 2.57 mL, t = 7.019, p < 0.001). ConclusionsOur study findings suggest that the closure of irreversible TM perforation by interlayer implantation using an interposition xenograft derived from porcine SIS produces favorable outcomes compared with those of inner tragus cartilage repair using the TM. This method offers distinct advantages, including the absence of donor-site morbidity, ease of graft modification and manipulation, and superior cosmetic results.

A Tissue Engineered 3D Model of Cancer Cell Invasion for Human Head and Neck Squamous-Cell Carcinoma.

Head and neck squamous-cell carcinoma (HNSCC) is associated with aggressive local invasiveness, being a main reason for its poor prognosis. The exact mechanisms underlying the strong invasive abilities of HNSCC remain to be elucidated. Therefore, there is a need for in vitro models to study the interplay between cancer cells and normal adjacent tissue at the invasive tumor front. To generate oral mucosa tissue models (OMM), primary keratinocytes and fibroblasts from human oral mucosa were isolated and seeded onto a biological scaffold derived from porcine small intestinal submucosa with preserved mucosa. Thereafter, we tested different methods (single tumor cells, tumor cell spots, spheroids) to integrate the human cancer cell line FaDu to generate an invasive three-dimensional model of HNSCC. All models were subjected to morphological analysis by histology and immunohistochemistry. We successfully built OMM tissue models with high in vivo-in vitro correlation. The integration of FaDu cell spots and spheroids into the OMM failed. However, with the integration of single FaDu cells into the OMM, invasive tumor cell clusters developed. Between segments of regular epithelial differentiation of the OMM, these clusters showed a basal membrane penetration and lamina propria infiltration. Primary human fibroblasts and keratinocytes seeded onto a porcine carrier structure are suitable to build an OMM. The HNSCC model with integrated FaDu cells could enable subsequent investigations into cancer cell invasiveness.

Varying Properties of Extracellular Matrix Grafts Impact Their Durability and Cell Attachment and Proliferation in an In Vitro Chronic Wound Model

While acute wounds typically progress through the phases of wound healing, chronic wounds often stall in the inflammatory phase due to elevated levels of matrix metalloproteinases (MMPs) and proinflammatory cytokines. Dysregulated expression of MMPs can result in the breakdown of extracellular matrix (ECM) formed during the wound healing process, resulting in stalled wounds. Native collagen-based wound dressings offer a potential wound management option to sequester excess MMPs and support cellular interactions that allow wound progression through the natural healing process. Herein, we utilized commercially available ECM matrices, two derived from porcine small intestinal submucosa (PCMP, 2 layers; PCMP-XT, 5 layers) and one derived from propria submucosa (ovine forestomach matrix, OFM, 1 layer), to demonstrate the impact of processing methodologies (e.g., layering and crosslinking) on functional characteristics needed for the management of chronic wounds. Grafts were evaluated for structural composition using scanning electron microscopy and histology, ability to reduce MMPs using fluorometric assays, and durability in an in vitro degradation chronic wound model. Both intact (nondegraded) and partially degraded grafts were assessed for their ability to serve as a functional cell scaffold using primary human fibroblasts. Grafts differed in matrix substructure and composition. While all grafts demonstrated attenuation of MMP activity, PCMP and PCMP-XT showed larger reductions of MMP levels. OFM rapidly degraded in the in vitro degradation model (&lt;3 hours), while PCMP and PCMP-XT were significantly more durable (&gt;7 days). The ability of PCMP and PCMP-XT to serve as scaffolds for cellular attachment was not impacted by degradation in vitro. Three ECM grafts with varying structural and functional characteristics exhibited differential durability when degraded in a simulated chronic wound model. Those that withstood rapid degradation maintained their ability to function as a scaffold to support attachment and proliferation of fibroblasts, a cell type important for wound healing.

Application of multi-layer porcine small intestinal submucosa for the reconstruction of deep corneal defects in cats.

This study documented the application of porcine small intestinal submucosa (SIS) as a stand-alone scaffold for treating deep corneal defects in cats. Medical records of 20 cats with deep stromal ulcers, perforations, or corneal sequestra that underwent surgical treatment with SIS grafts between 2021 and 2022 were retrospectively reviewed. Data on re-epithelialization time, corneal transparency score, and complications were collected to analyze the reconstruction of deep corneal defects after SIS biomaterial implantation. All cats were unilaterally affected. The corneal defects varied in size, with a median diameter of 8.3 mm (range: 3-15 mm). Re-epithelialization of the SIS graft was completed 16-32 days after surgery (median, 22.3 days). No, mild, or moderate corneal transparency was detected in 90% of the cases. Complications were observed in eight cases (40%), including aqueous leakage (10%), partial SIS malacia (25%), and persistent bullous keratopathy (5%). The follow-up period ranged 90-725 days, with a median duration of 255 days. The SIS graft was successfully applied as a single scaffold in 17 of 20 cases (85%). The results of this study suggest that the application of commercial SIS is an effective surgical technique for managing deep corneal defects in cats.

Composite Biosynthetic Graft for Repair of Long-Segment Tracheal Stenosis: A Pilot In Vivo and In Vitro Feasibility Study.

Pediatric patients who undergo surgery for long-segment congenital tracheal stenosis (LSCTS) have suboptimal outcomes and postsurgical complications. To address this, we propose a biosynthetic graft comprising (1) a porcine small intestinal submucosa extracellular matrix (SIS-ECM) patch for tracheal repair, and (2) a resorbable polymeric exostent for biomechanical support. The SIS-ECM patch was evaluated in vivo in an ovine trachea model over an 8 month period. Concurrently, the biosynthetic graft was evaluated in a benchtop lamb trachea model for biomechanical stability. In vivo results show that SIS-ECM performs better than bovine pericardium (control) by preventing granulation tissue/restenosis, restoring tracheal architecture, blood vessels, matrix components, pseudostratified columnar and stratified epithelium, ciliary structures, mucin production, and goblet cells. In vitro tests show that the biosynthetic graft can provide the desired axial and flexural stability, and biomechanical function approaching that of native trachea. These results encourage future studies to evaluate safety and efficacy, including biomechanics and collapse risk, biodegradation, and in vivo response enabling a stable long-term tracheal repair option for pediatric patients with LSCTS and other tracheal defects.

Human umbilical cord mesenchymal stem cells combined with porcine small intestinal submucosa promote the healing of full-thickness skin injury in SD rats

Aim: To assess the therapeutic potential of human umbilical cord mesenchymal stem cells (hUCMSCs) combined with porcine small intestinal submucosa (SIS) on full-thickness skin injuries in rats. Methods: We established full-thickness skin injury models in Sprague–Dawley rats, dividing them into blank control, SIS, hUCMSCs and hUCMSCs combined with SIS. We monitored wound healing, scores and area, and analyzed inflammatory cells, microvessel density and collagen fibers after 12 days. Results: The blank group showed no healing, forming a scar of 0.6 × 0.5 cm2, while SIS and hUCMSCs groups exhibited incomplete healing with 0.4 × 0.5 cm2 scabs. Wound healing was significantly better in the hUCMSCs combined with the SIS group. Conclusion: Local application of hUCMSCs combined with SIS enhances full-thickness skin injury wound healing in rats.

Viscoelastic Properties of Acellular Matrices of Porcine Esophageal Mucosa and Comparison with Acellular Matrices of Porcine Small Intestine Submucosa and Bovine Pericardium.

The aim of this study was to compare the viscoelastic properties of a decellularized mesh from the porcine esophagus, prepared by our group, with two commercial acellular tissues derived from porcine small intestine submucosa and bovine pericardium for use in medical devices. The tissues' viscoelastic properties were characterized by creep tests in tension, applying the load in the direction of the fibers or the transverse direction, and also by dynamic-shear mechanical tests between parallel plates or in tension at frequencies between 0.1 and 35 Hz. All the tests were performed in triplicate at a constant temperature of 37 °C immersed in distilled water. The tissues' surface and cross-sectional microstructure were observed by scanning electron microscopy (SEM) to characterize the orientation of the fibers. The matrices of the porcine esophagus present an elastic modulus in the order of 60 MPa when loaded in the longitudinal direction while those of the porcine intestine submucosa and bovine pericardium have an elastic modulus below 5 MPa. Nevertheless, the shear modulus of bovine pericardium nearly triplicates that of the esophageal matrix. The viscoelasticity of decellularized esophageal mucosa is characterized by a fast change in the creep compliance with time. The slope of the creep curve in the double logarithmic plot is twice that of the control samples. These results are consistent with the microstructure observed under electron microscopy regarding the orientation of the fibers that make up the matrices.

A pleiotropic SIS-based hydrogel with immunomodulation via NLRP3 inflammasome inhibition for diabetic bone regeneration

As a progressive inflammatory disease, diabetes mellitus significantly changes the immuno-microenvironment, causing an elevation in M1 macrophages and inflammatory mediators. This inflammation condition possesses a negative impact on the cellular function of osteoblasts and vascular endothelial cells, resulting in impaired bone defect repair involving both angiogenesis and osteogenesis. In our study, a good biocompatible hydrogel, GB@SIS, was successfully fabricated for bone repair under diabetic conditions. This hydrogel consists of a porcine small intestinal submucosal (SIS) extracellular matrix with thermosensitivity, bionic structure, and pro-angiogenic properties, and BMP-4 loaded on graphene oxide (GO) can be sustainably released from the hydrogel. In vitro studies have shown that the composite hydrogel possesses a good ability to promote angiogenesis and enhance osteogenesis. Additionally, the hydrogel was also able to promote macrophage conversion from M1 to M2 macrophages, which subsequently results in the release of osteogenesis-related factors, specifically BMP-2. In a diabetic rat model with critical-size cranial defects, the GB@SIS hydrogel modulates the inflammatory microenvironment and significantly accelerates the process of bone repair. Subsequent investigations have revealed that the GB@SIS hydrogel exerts immunomodulatory effects via the suppression of the NLRP3 signaling pathway and the elevation of adhesion-related protein expression. In conclusion, the GB@SIS hydrogel demonstrates promising osteogenic characteristics as a biomaterial, exhibiting bone immunomodulatory properties that hold potential for its application in bone regeneration therapy specifically for diabetic patients.

Use of a Porcine Small Intestinal Submucosa Graft to Treat a Degloving Injury in an American Bullfrog (Rana catesbeiana)

Abstract A free-ranging adult female American bullfrog (Rana catesbeiana) presented with a degloving injury to the right manus. Insufficient healthy cutaneous tissue remained on the manus for primary closure. A porcine small intestinal submucosa (SIS) graft was sutured over the wound to promote skin regeneration. Additional treatment included gentamicin solution immersion therapy followed by topical glycerin impregnated with insulin and SilvaSorb® Gel. The initial porcine SIS graft began to fail after five days and was replaced. The second porcine SIS graft began to break down nine days after placement. The graft was allowed to disintegrate after a strong granulation bed had formed and served as a form of mechanical protection. Application of the porcine SIS graft in combination with gentamicin therapy and topical treatment resulted in complete healing of the manus 35 days after the initial placement of the porcine SIS graft and the patient was released.

Histatin 1-modified SIS hydrogels enhance the sealing of peri-implant mucosa to prevent peri-implantitis

Dental implants make it possible to replace teeth in more sophisticated ways. Nevertheless, peri-implantitis is one of the leading causes of implant failure, which can be avoided with proper soft tissue sealing. The aim of this study was to achieve the promotion of the synthesis of peri-implant epithelial hemidesmosome through Histatin 1 and porcine small intestinal submucosa (SIS) hydrogel to form a good peri-implant seal. The results show that hydrogel can improve the biological barrier function around implants by combining antibacterial, promoting soft tissue healing and promoting epithelial bonding. This means that the morphology and anti-infection ability of soft tissue are enhanced, which ensures the long-term stability of the implant.SIS-Hst1 hydrogel has certain clinical application in the prevention and early treatment of peri-implantitis. In conclusion, Hst1-SIS hydrogel, as a local administration system, provides experimental evidence for the prevention of peri-implant disease.

Killing two birds with one stone: A therapeutic copper-loaded bio-patch promoted abdominal wall repair via VEGF pathway.

Hernia and life-threatening intestinal obstruction often result from abdominal wall injuries, and the regeneration of abdominal wall defects is limited due to the lack of biocompatible, antibacterial and angiogenic scaffolding materials for treating injured tissues. Taking inspiration from the facile preparation of dopamine polymerization and its surface modification technology, in this study, multi-therapeutic copper element was introduced into porcine small intestinal submucosa (SIS) bio-patches through polydopamine (PDA) deposition, in order to regenerate abdominal wall injury. In both in vitro antibacterial assays, cytocompatibility assays and in vivo abdominal wall repair experiments, the SIS/PDA/Cu bio-patches exhibited robust antibacterial efficiency (＞99%), excellent biocompatibility to cells (＞90%), and enhanced neovascularization and improved collagen maturity compared to other commercially available patches (3.0-fold higher than the PP mesh), due to their activation of VEGF pathway. These findings indicated the bio-patch was a promising application for preventing visceral adhesion, bacterial infection, and promoting soft tissue regeneration.

EGCG modified small intestine submucosa promotes wound healing through immunomodulation

Decellularized porcine small intestinal submucosa (SIS) has shown promising therapeutic efficacy as a functional wound dressing. Nevertheless, its limited anti-oxidative and immunomodulatory capacities have restricted its application for the treatment of complex skin wounds. Herein, epigallocatechin gallate (EGCG), a polyphenolic compound, was employed for the modification of the SIS to overcome such shortcomings. The EGCG-modified SIS (E-SIS) has shown excellent biocompatibility and improved hydrophilicity for cell adhesion. Notably, in vitro studies showed that the E-SIS could effectively alleviate oxidative stress and facilitate the M1-to-M2 phenotype transition of macrophages, thereby creating a favorable immune microenvironment for cell proliferation, migration, collagen synthesis as well as angiogenesis. A full-thickness skin defect model, combined with macrophage depletion, has further confirmed that the E-SIS could accelerate skin wound repair through immunomodulation in vivo. This suggested that the EGCG modification could provide a facile yet effective method to broaden the applications of the SIS for skin wound management.

Successful Use of Acellular Small Intestinal Submucosa Graft in Vaginal Reconstruction

PurposeVarious techniques for neovaginal construction have been employed in the pediatric and adult populations, including the use of intestinal segments, buccal mucosal grafts, and skin grafts. Small intestinal submucosa (SIS) extracellular matrix grafts have been described as a viable alternative, though prior experience is limited. Our purpose was to assess operative characteristics and patient outcomes with neovaginal construction using SIS grafts. MethodsThirteen patients underwent vaginoplasty with acellular porcine SIS grafts at our institution between 2018 and 2022. Operative and clinical data, postoperative mold management, vaginal dilating length, and complications were reviewed. ResultsAge at time of repair ranged from 13 to 30 years (median 19 years). Patient diagnosis included cloacal anomalies (n = 4), Mayer-Rokitansky-Küster-Hauser syndrome (n = 4), isolated vaginal atresia with or without a transverse vaginal septum (n = 4), and vaginal rhabdomyosarcoma requiring partial vaginectomy (n = 1). Following dissection of the neovaginal space, a silicon mold wrapped with SIS graft was placed with retention sutures and removed on postoperative day 7. Median (IQR) operative time was 171 (118–192) minutes, estimated blood loss was 10 (5–20) mL, and length of stay was 2 (1–3) days. The follow-up period ranged from 3 to 47 months (median 9 months). Two patients developed postoperative vaginal stenosis that resolved with dilation under anesthesia. Mean vaginal length on latest follow-up was 8.97 cm. All thirteen patients had successful engraftment and progressed to performing self-dilations or initiating intercourse to maintain patency. There were no cases of graft reaction or graft extrusion. ConclusionsWe conclude that acellular small intestinal submucosa grafts are effective and safe alternatives for mold coverage in neovaginal construction. Our experience demonstrates minimal perioperative morbidity, early mold removal, and progression to successful dilation with maintenance of a functional vaginal length. Future study on sexual outcomes, patient satisfaction, and comparison against alternative techniques has been initiated. Level of EvidenceIV. Type of StudyRetrospective Study.

Optimization of decellularization methods using human small intestinal submucosa for scaffold generation in regenerative medicine.

Porcine small intestinal submucosa, despite its successful use as a scaffold in regenerative medicine, has innate biomechanical heterogeneity. In this study, we hypothesized that human small intestinal submucosa could be a viable alternative bio-scaffold. For the first time, we characterize submucosal extraction from human small intestine and examine appropriate decellularization methods. In total, 16 human small intestinal submucosal samples were obtained and decellularized using three reported methods of porcine decellularization: Abraham, Badylak, and Luo. For each method, four specimens were decellularized. The remaining four specimens were designated as non-decellularized. We measured the amount of residual DNA and growth factors in decellularized human intestinal samples. Additionally, decellularized human small intestinal submucosa was co-cultured with mouse bone marrow-derived mesenchymal stem cells to examine mesenchymal stem cell survival and proliferation. The reference value for the amount of residual DNA deemed appropriate in decellularized tissue was established as 50 ng/mg of extracellular matrix dry weight or less. Abraham's method most successfully met this criterion. Measurement of residual growth factors revealed low levels observed in samples decellularized using the Abraham and Badylak methods. Co-culture of each small intestinal submucosal sample with mouse bone marrow-derived mesenchymal stem cells confirmed viable cell survival and proliferation in samples derived using protocols by Abraham and Badylak. Abraham's method most successfully met the criteria for efficient tissue decellularization and cell viability and proliferation. Thus, we consider this method most suitable for decellularization of human small intestinal submucosa.

Reduced fibrous capsule elastic fibers from biologic ECM-enveloped CIEDs in minipigs, supported with a novel compression mechanics model.

Fibrous capsules (Fb) in response to cardiovascular implantable electronic devices (CIEDs), including a pacemaker (P) system, can produce patient discomfort and difficulties in revision surgery due partially to their increased compressive strength, previously linked to elevated tissue fibers. A preliminary study to quantify structural proteins, determine if biologic extracellular matrix-enveloped CIEDs (PECM) caused differential Fb properties, and to implement a realistic mechanical model. Retrieved Fb (-P and -PECM) from minipigs were subjected to biomechanical (shear oscillation and uniaxial compression) and histological (collagen I and elastin) analyses. Fb-PECM showed significant decreases compared to Fb-P in: low strain-loss modulus (390 vs. 541Pa) across angular frequencies, high strain-compressive elastic modulus (1043 vs. 2042kPa), and elastic fiber content (1.92 vs. 3.15μg/mg tissue). Decreases in elastin were particularly noted closer to the implant's surface (Fb-PECM = 71% vs. Fb-P = 143% relative to dermal elastin at mid-tangential sections) and verified with a solid mechanics hyperelasticity with direction-dependent fiber viscoelasticity compression simulation (r2 ≥98.9%). The biologic envelope composed of decellularized porcine small intestine submucosa ECM for CIEDs promoted fibrous tissues with less elastic fibers. Novel compression modeling analyses directly correlated this singular reduction to more desirable subcutaneous tissue mechanics.

Development of a Silk Fibroin-Small Intestinal Submucosa Small-Diameter Vascular Graft with Sequential VEGF and TGF-β1 Inhibitor Delivery for In Situ Tissue Engineering.

Proper endothelialization and limited collagen deposition on the luminal surface after graft implantation plays a crucial role to prevent the occurrence of stenosis. To achieve these conditions, a biodegradable graft with adequate mechanical properties and the ability to sequentially deliver therapeutic agents isfabricated. In this study, a dual-release system is constructed through coaxial electrospinning by incorporating recombinant human vascular endothelial growth factor (VEGF) and transforming growth factor β1 (TGF-β1) inhibitor into silk fibroin (SF) nanofibers to form a bioactive membrane. The functionalized SF membrane as the inner layer of the graft is characterized by the release profile, cell proliferation and protein expression. It presents excellent biocompatibility and biodegradation, facilitating cell attachment, proliferation, and infiltration. The core-shell structure enables rapid VEGF release within 10 days and sustained plasmid delivery for 21 days. A 2.0-mm-diameter vascular graft is fabricated by integrating the SF membrane with decellularized porcine small intestinal submucosa (SIS), aiming to facilitate the integration process under a stable extracellular matrix structure. The bioengineered graft is functionalized with the sequential administration of VEGF and TGF-β1, and with the reinforced and compatible mechanical properties, thereby offers an orchestrated solution for stenosis with potential for in situ vascular tissue engineering applications.

In Vivo Efficacy of a Novel, Sutureless Coaptation Device for Repairing Peripheral Nerve Defects.

Although microsuture neurorrhaphy is the accepted clinical standard treatment for severed peripheral nerves, this technique requires microsurgical proficiency and still often fails to provide adequate nerve approximation for effective regeneration. Entubulation utilizing commercially available conduits may enhance the technical quality of the nerve coaptation and potentially provide a proregenerative microenvironment, but still requires precise suture placement. We developed a sutureless nerve coaptation device, Nerve Tape®, that utilizes Nitinol microhooks embedded within a porcine small intestinal submucosa backing. These tiny microhooks engage the outer epineurium of the nerve, while the backing wraps the coaptation to provide a stable, entubulated repair. In this study, we examine the impact of Nerve Tape on nerve tissue and axonal regeneration, compared with repairs performed with commercially available conduit-assisted or microsuture-only repairs. Eighteen male New Zealand white rabbits underwent a tibial nerve transection, immediately repaired with (1) Nerve Tape, (2) conduit plus anchoring sutures, or (3) four 9-0 nylon epineurial microsutures. At 16 weeks postinjury, the nerves were re-exposed to test sensory and motor nerve conduction, measure target muscle weight and girth, and perform nerve tissue histology. Nerve conduction velocities in the Nerve Tape group were significantly better than both the microsuture and conduit groups, while nerve compound action potential amplitudes in the Nerve Tape group were significantly better than the conduit group only. Gross morphology, muscle characteristics, and axon histomorphometry were not statistically different between the three repair groups. In the rabbit tibial nerve repair model, Nerve Tape offers similar regeneration efficacy compared with conduit-assisted and microsuture-only repairs, suggesting minimal impact of microhooks on nerve tissue.

Bridging Gaps in Peripheral Nerves: From Current Strategies to Future Perspectives in Conduit Design.

In peripheral nerve injuries (PNI) with substance loss, where tensionless end-to-end suture is not achievable, the positioning of a graft is required. Available options include autografts (e.g., sural nerve, medial and lateral antebrachial cutaneous nerves, superficial branch of the radial nerve), allografts (Avance®; human origin), and hollow nerve conduits. There are eleven commercial hollow conduits approved for clinical, and they consist of devices made of a non-biodegradable synthetic polymer (polyvinyl alcohol), biodegradable synthetic polymers (poly(DL-lactide-ε-caprolactone); polyglycolic acid), and biodegradable natural polymers (collagen type I with/without glycosaminoglycan; chitosan; porcine small intestinal submucosa); different resorption times are available for resorbable guides, ranging from three months to four years. Unfortunately, anatomical/functional nerve regeneration requirements are not satisfied by any of the possible alternatives; to date, focusing on wall and/or inner lumen organization/functionalization seems to be the most promising strategy for next-generation device fabrication. Porous or grooved walls as well as multichannel lumens and luminal fillers are the most intriguing options, eventually also including the addition of cells (Schwann cells, bone marrow-derived, and adipose tissue derived stem cells) to support nerve regeneration. This review aims to describe common alternatives for severe PNI recovery with a highlight of future conduits.

Efficacy of endoscopic porcine small intestinal submucosa graft myringoplasty: a retrospective comparative study

Background The surgical outcomes following tympanic membrane (TM) repair are affected by many factors. Objectives To evaluate the efficacy of endoscopic porcine small intestine submucosa graft (PSISG) myringoplasty by comparing with endoscopic myringoplasty with temporal fascia (TF) and perichondrium (PC). Methods We conducted a retrospective comparative study that a total of 98 patients with TM perforations were included. The patients underwent endoscopic myringoplasty using PSISG, TF or PC as the graft. The closure rate, hearing outcomes, operative time and complications in three groups were compared. Results At 3 months postoperatively, the closure rate were 85.2% (23/27), 92.1% (35/38) and 87.9% (29/33) in the PSISG, TF and PC groups respectively (p = .667); Hearing improved after surgery in three groups (p < .001), and showed no significant difference among the three groups. The mean operative time of the PSISG group was shorter than autologous TF (p < .001) and PC groups (p < .001) in this study; No operative or postoperative complications were found among the three groups. Conclusion Compare to autologous temporal fascia or perichondrium, the PSISG appears to be an effective and safe material for TM perforations closure. Endoscopic PSISG myringoplasty may be an alternative technique for repairing TM perforations, especially for revision cases.