Collagen Graft Research Articles

Management of Massive Iatrogenic Temporal Lobe Meningoencephalocele and Bacterial Meningitis Following Pediatric Cochlear Implant Surgery.

To review the management of meningitis, large lateral skull base defect, and meningoencephalocele following pediatric cochlear implant (CI) surgery. Case report. Patient demographics, medical and surgical history, computed tomography (CT). An 8-year-old male with congenital severe to profound sensorineural hearing loss underwent uncomplicated right CI surgery at 18 months of age. He returned to his home country and received a bilateral sequential left ear CI at age 2. Five years following his second CI surgery, he presented to his local emergency room with worsening fever, headache, back pain, and vomiting. Lumbar puncture confirmed bacterial meningitis, and he was managed with intravenous antibiotics. The hospital course was complicated by a right-sided facial nerve paresis, prompting a temporal bone CT. Imaging demonstrated a tegmen defect measuring 15 mm × 10 mm with soft tissue opacification involving the entire mastoid and CI harness. He was then referred by family back to our institution. Intraoperatively, we identified a massive temporal lobe meningoencephalocele involving the entire mastoid cavity and engulfing the entire proximal electrode harness. Following middle cranial fossa craniotomy and revision mastoidectomy, proximal and distal array were separated, encephalocele transected, and remaining temporal lobe reduced. The lateral skull base was reconstructed with calvarial bone, temporalis fascia, and bovine collagen graft. The remnant electrode array was removed, a new CI receiver stimulator was fixed postero-superiorly to the cranial defect, and a new multichannel array inserted. A titanium cranioplasty completed the repair. A lumbar drain was placed for 3 days. Recovery and CI activation occurred uneventfully. Risk of encephalocele and meningitis underscores the importance of early identification, adequate repair, and long-term radiologic follow-up of iatrogenic tegmen defects during pediatric CI surgery.

Ionically-crosslinked carboxymethyl chitosan scaffolds by additive manufacturing for antimicrobial wound dressing applications

Chitosan chemical functionalization is a powerful tool to provide novel materials for additive manufacturing strategies. The main aim of this study was the employment of computer-aided wet spinning (CAWS) for the first time to design and fabricate carboxymethyl chitosan (CMCS) scaffolds. For this purpose, the synthesis of a chitosan derivative with a high degree of O-substitution (1.07) and water soluble in a large pH range allowed the fabrication of scaffolds with a 3D interconnected porous structure. In particular, the developed scaffolds were composed of CMCS fibers with a small diameter (< 60 μm) and a hollow structure due to a fast non solvent-induced coagulation. Zn2+ ionotropic crosslinking endowed the CMCS scaffolds with stability in aqueous solutions, pH-sensitive water uptake capability, and antimicrobial activity against Escherichia coli and Staphylococcus aureus. In addition, post-printing functionalization through collagen grafting resulted in a decreased stiffness (1.6 ± 0.3 kPa) and a higher elongation at break (101 ± 9 %) of CMCS scaffolds, as well as in their improved ability to support in vitro fibroblast viability and wound healing process. The obtained results encourage therefore further investigation of the developed scaffolds as antimicrobial wound dressing hydrogels for skin regeneration.

The Intra-articular Tendinous Graft Diameter of 10-mm Bone-Patellar Tendon-Bone Autografts in Adolescent Patients: An MRI Analysis of 100 Patients.

Bone-patellar tendon-bone (BPTB) autograft size may be one modifiable predictor of anterior cruciate ligament (ACL) reconstruction postoperative success, as smaller graft diameter has been associated with higher rates of rupture requiring revision. However, measuring the true intra-articular tendinous graft diameter of the soft tissue portion of a BPTB graft with standard intraoperative methods is difficult while keeping the graft intact. The purpose of the study was to use 3-dimensional magnetic resonance imaging (MRI) measurements to determine the cross-sectional area of the soft tissue, tendinous portion of a standard BPTB autograft with 10-mm diameter bone plugs, and, by calculation, the collagen graft size (ie, graft diameter), as would typically be reported in ACL reconstruction studies that consider soft tissue graft size. It was hypothesized that the calculated collagen graft diameter of 10-mm BPTB autografts would be significantly smaller than 10 mm. Cross-sectional study; Level of evidence, 3. A total of 100 patients (10 girls and 10 boys at each age from 13 to 17 years) who underwent a knee MRI at a single academic orthopaedic center without documented extensor mechanism pathology were identified. The central 10-mm width of the patellar tendon that would be harvested for BPTB autograft was measured. The region of interest area tool was then used to measure the cross-sectional area of a 10-mm BPTB graft with subsequent soft tissue autograft diameter calculation. The mean calculated tendinous graft diameter of a 10 mm-wide BPTB graft was 6.3 ± 0.5 mm and was significantly smaller than a 10-mm reference (P≤ .001). There was no significant association between age and cross-sectional area or graft diameter. Modern 3-dimensional imaging-based measurement techniques demonstrated that the true intra-articular tendinous soft tissue portion of 10-mm BPTB autografts shows substantial variation and is significantly smaller in diameter than the tunnels typically reamed to accommodate the bone plug portions of these grafts. Moreover, as graft size is a predictor of rupture rate, preoperative MRI-based evaluation may be an important tool when considering BPTB autograft for ACL reconstruction. Future comparative clinical research utilizing graft size as a study variable should consider quantifying and utilizing the diameter of the soft tissue component of BPTB autografts.

Recombinant Platelet-Derived Growth Factor-BB (rhPDGF-BB) Augmented Collagen Grafting for Oral Mucosal Defect Reconstruction

Abstract Objective To assess the suitability of collagen grafting and compare the outcomes between rhPDGF-BB (recombinant human platelet-derived growth factor-BB) augmented collagen grafting and collagen alone grafting for oral mucosal defect reconstruction. Method A total of 30 patients, who were planned for surgical excision of various intraoral lesions, participated in the study. These participants were then randomly assigned into two groups. Group I underwent reconstruction with collagen sheet with rhPDGF-BB, while group II underwent reconstruction with collagen sheet alone. Post-operatively, haemostasis, pain, granulation, epithelialisation and healing contracture were assessed. Results The lesions that were treated included leucoplakia, erythroplakia, oral submucous fibrosis and verrucous carcinoma. Use of collagen was associated with good haemostasis, pain relief, granulation tissue formation and epithelialisation. Group I was found to develop slightly better granulation tissue, epithelisation and lesser degree of tissue contracture compared to group II, although these results were not significant statistically (p value = 0.464, 0.705 and 1.000 respectively). Conclusion This study shows that use of collagen graft augmented with rhPDGF-BB could be beneficial in oral cavity reconstruction following resection of small lesions, although further research with larger sample size is proposed to confirm the benefit.

Collagen Matrix to Restore the Tympanic Membrane: Developing a Novel Platform to Treat Perforations.

Modern otology faces challenges in treating tympanic membrane (TM) perforations. Instead of surgical intervention, alternative treatments using biomaterials are emerging. Recently, we developed a robust collagen membrane using semipermeable barrier-assisted electrophoretic deposition (SBA-EPD). In this study, a collagen graft shaped like a sponge through SBA-EPD was used to treat acute and chronic TM perforations in a chinchilla model. A total of 24 ears from 12 adult male chinchillas were used in the study. They were organized into four groups. The first two groups had acute TM perforations and the last two had chronic TM perforations. We used the first and third groups as controls, meaning they did not receive the implant treatment. The second and fourth groups, however, were treated with the collagen graft implant. Otoscopic assessments were conducted on days 14 and 35, with histological evaluations and TM vibrational studies performed on day 35. The groups treated with the collagen graft showed fewer inflammatory changes, improved structural recovery, and nearly normal TM vibrational properties compared to the controls. The porous collagen scaffold successfully enhanced TM regeneration, showing high biocompatibility and biodegradation potential. These findings could pave the way for clinical trials and present a new approach for treating TM perforations.

Экспериментальное обоснование использования 1% раствора гидроксипропилметилцеллюлозы для защиты эндотелия заднего послойного трансплантата роговицы при его выкраивании низкоэнергетическим фемтосекундным лазером по инвертированной методике

Purpose. To evaluate experimentally endothelial cell loss of animal's cornea during inverted posterior lamellar corneal graft preparation technique by low-energy femtosecond laser with and without ophthalmic viscosurgical device (OVD) – 1% hydroxypropyl methylcellulose (HPMC) solution application. Material and methods. Posterior lamellar corneal grafts were created using a femtosecond laser (FSL). In the control group (n=16), a few drops of corneal storage solution were applied to the endothelium just before applanation, in the experimental group (n=16) – 1% HPMС. The quality of the applanation were monitored using an integrated in laser OCT system. The endothelial viability was determined using live/dead cells assay and the grafts were examined on a confocal laser scanning microscope. The obtained images were analyzed to count live and dead endothelial cells (EC). To assess the state of collagen fibers of the stromal side of the graft, samples from the control and experimental groups were examined using a scanning electron microscope (SEM). Results. According to the OCT, in all samples of both groups, a flat profile of the contact zone between the laser head and the endothelial monolayer was observed during applanation. The difference between the number of live and dead ECs was statistically significant between both groups. There were 2854 [2819; 2879] live cells/mm² in the control group, and 3477 [3426; 3719] live cells/mm² in the experimental group (p&lt;0.001). Thus, the number of dead ECs in the control group was 710 [649; 728] cells/mm² . The number of dead ECs in the experimental group was 402 [366; 427] cells/mm² (p&lt;0.001). When analyzing the images obtained on a SEM, the preservation of the architectonics of the graft collagen fibers with their single defibrations in both groups was observed. Conclusion. Application of 1% HPMC provides protection for endothelial cells from damage during posterior laser dissection using an FSL. In the study group, the number of endothelial cells was 9.92% higher than in the control group. The presence of the OVD layer in the interface between the head of the FSL and the EC did not affect the formation of an effective laser cut and did not reduce the quality of the stromal surface of the graft. The inverted technique FSL cut using a 1% solution of HPMC on the surface of the endothelium may be recommended for use in clinical practice. Key words: endothelium, keratocytes, corneal transplantation, keratoplasty, posterior lamellar keratoplasty, femtosecond laser, ophthalmic viscosurgical device, hydroxypropyl methylcellulose, confocal microscopy, scanning electron microscopy

Poster 105: Rotator cuff healing using demineralised bone fibers in ovine infraspinatus tendon models

Objectives: Rotator cuff tears are a common cause of shoulder pain and functional deficits. Although surgical repair is often able to restore function and resolve pain, high rates of postoperative structural failures have been reported. To improve the outcomes and reduce re-tear rates biologic tissue scaffolds have been used to augment and reinforce the primary tendon repair by providing mechanical support of the initial repair and ideally improving the rate and/or quality of biological healing at the tendon-bone interface. Demineralised bone fibers (DBF) are bone collagen and can be formed into a patch providing a scaffold and inductive bone morphogenetic proteins known to facilitate healing. This study evaluated the in vivo response of human DBF Patches (hDBF-P) as an onlay over the infraspinatus tendon (IST) and at the tendon-bone interface in an ovine model. Methods: The hDBF-P was characterised using stereozoom (Figure 1A) and environment electron microscopy (Figure 1B). The osteoinductivity (OI) was evaluated in the standard nude rat intramuscular implantation (IM) model at 28 days using mCT and paraffin histology. A bilateral model of an onlay or an enthesis repair was performed in 12 adult wethers following ethical approval. Four groups were evaluated at 6 and 12 weeks (n=3 per time point): Onlay control and hDBF treated; Enthesis repair control and hDBF treated. The onlay model simulated a tendon injury by 4 longitudinal slits along the IST and lateral drill holes in the proximal humerus in the onlay control group [1]. In the onlay treated group the hDBF-P was hydrated in saline and secured to the IST with interrupted 2-0 non-resorbable sutures (Figure 2A). On contralateral side, the central third of the IST was sharply dissected, the footprint burred, and 2 medial row anchors inserted. The sutures were passed through the IST in the enthesis repair control group. In the enthesis repair treatment group, the sutures were passed through the hDBF-P which was placed at the tendon bone interface followed by sutures through the IST. Two lateral push lock anchors were used for a suture bridge (Figure 2B) in the control and treated groups. Endpoints included clinical recovery, macroscopic dissection, 3T MRI, radiographs, mCT and paraffin histology processing, H&amp;E staining, and light microscopic evaluations to assess local cell and tissue responses and healing. Results: OI was confirmed on IM implantation in nude rats. The sheep recovered uneventfully with no adverse events macroscopically or radiographically. MRI in the onlay control group revealed little response and no increase in tendon thickness which was confirmed histologically. In contrast the onlay hDBF-P treated demonstrated increased tendon thickness and hDBF resorption with time. Histology showed some initial inflammatory cells that decrease with time in the onlay group. MRI in the hDBF-P treated enthesis group supported increased activity at the bone interface at 6 and 12 weeks compared to controls. Histology at the interface with hDBF-P showed evidence of new bone formation at 6 weeks that matured with time support enthesis reformation. Conclusions: hDBF-P is a collagen graft composed of demineralized bone fibers that have osteoconductive and osteoinductive potential. When formed into a patch, this implant provides a scaffold that can participate with the local biology. hDBF-P used as on-lay in a tendon injury model increased tendon thickness. hDBF-P when used at the interface between the tendon and bone facilitated enthesis reformation through its conductive and inductive potential as well as scaffold architecture. DBF patches represent an exciting allograft implant with the potential to address the clinical problems in rotator cuff surgery. Literature cited Van Kampen, C., et al. (2013). Tissue-engineered augmentation of a rotator cuff tendon using a reconstituted collagen scaffold: a histological evaluation in sheep. Muscles, ligaments and tendons journal, 3(3), p.229.

Incidence, Risk Factors, and Outcomes of Incidental Durotomy during Lumbar Spine Decompression with or without Fusion.

Retrospective cohort study. The primary objective of this study was to determine the incidence and risk factors for incidental durotomies during lumbar decompression surgeries. In addition, we aimed to determine the changes in patient-reported outcome measures (PROMs) based on incidental durotomy status. There is limited literature investigating the affect of incidental durotomy on patient reported outcome measures. While the majority of research does not suggest differences in complications, readmission, or revision rates, many studies rely on public databases, and their sensitivity and specificity for identifying incidental durotomies is unknown. Patients undergoing lumbar decompression with or without fusion at a single tertiary care center were grouped based on the presence of a durotomy. Multivariate analysis was performed for length of stay (LOS), hospital readmissions, and changes in PROMs. To identify surgical risk factors for durotomy, 3:1 propensity matching was performed using stepwise logistic regression. The sensitivity and specificity of the International Classification of Disease, 10th revision (ICD-10) codes (G96.11 and G97.41) were also assessed. Of the 3,684 consecutive patients who underwent lumbar decompressions, 533 (14.5%) had durotomies, and a complete set of PROMs (preoperative and 1-year postoperative) were available for 737 patients (20.0%). Incidental durotomy was an independent predictor of increased LOS but not hospital readmission or worse PROMs. The durotomy repair method was not associated with hospital readmission or LOS. However, repair with collagen graft and suture predicted reduced improvement in Visual Analog Scale back (β =2.56, p=0.004). Independent risk factors for incidental durotomies included revisions (odds ratio [OR], 1.73; p<0.001), levels decompressed (OR, 1.11; p=0.005), and preoperative diagnosis of spondylolisthesis or thoracolumbar kyphosis. The sensitivity and specificity of ICD-10 codes were 5.4% and 99.9%, respectively, for identifying durotomies. The durotomy rate for lumbar decompressions was 14.5%. No differences in outcomes were detected except for increased LOS. Database studies relying on ICD codes should be interpreted with caution due to the limited sensitivity in identifying incidental durotomies.

The Use of Collagen Matrix in the Treatment of Gingival Recession-A Pilot Study.

Gingival recessions are common mucogingival deformities and conditions around teeth, which are described as the apical migration of tissues in the relation to the cementoenamel junction. One of the types of graft materials used to treat these recessions is the collagen graft material. The aim of this pilot study was to evaluate the effectiveness of the use of the collagen matrix combined with the coronally advanced flap surgery method to cover dental recessions, after a 12 month follow-up period. The following parameters were assessed in 20 patients, with 38 single or multiple Miller class I or II gingival recessions: depth of the recession-RD; width of the recession-RW; height of the keratinized tissue-HKT; and thickness of the keratinized gingivae-GT. The percentage of the root coverage after 12 months was also calculated. There was a significant difference in the RD and RW values before and after the procedure. On average, the RD decreased by 3.39 mm, and the RW by 3.87 mm. Moreover, the values of the GT and HKT, before and after the treatment, significantly increased by 0.98 mm and 1.13 mm, respectively. The partial root coverage was 43.48%, and the total root coverage was 56.52%. The use of the collagen matrix with a split thickness gingival flap to cover the gingival recessions is a predictable and effective method when the clinician carefully follows the recommendation of the producer, which was confirmed in a 1 year follow-up with good clinical results.

A Uterus-Inspired Niche Drives Blastocyst Development to the Early Organogenesis.

The fundamental physical features such as the mechanical properties and microstructures of the uterus need to be considered when building in vitro culture platforms to mimic the uterus for embryo implantation and further development but have long been neglected. Here, a uterus‐inspired niche (UN) constructed by grafting collagen gels onto polydimethylsiloxane based on a systematic investigation of a series of parameters (varying concentrations and thicknesses of collagen gel) is established to intrinsically specify and simulate the mechanics and microstructures of the mouse uterus. This brand‐new and unique system is robust in supporting embryo invasion, as evidenced by the special interaction between the embryos and the UN system and successfully promoting E3.5 embryo development into the early organogenesis stage. This platform serves as a powerful tool for developmental biology and tissue engineering.

Improvement of Ocular Surface Disease by Lateral Tarsoconjunctival Flap in Thyroid-Associated Orbitopathy Patients with Lid Retraction.

There is a high incidence of ocular surface disease (OSD) in thyroid-associated orbitopathy (TAO) patients as a result of incomplete eyelid closure and chronic inflammatory eyelid status. This study was performed to evaluate the efficacy of a lateral tarsoconjunctival flap (LTF) in improving OSD in TAO patients from the perspective of correcting eyelid closures. As a study design, TAO patients were enrolled in this study to evaluate OSD perioperatively before they were scheduled for LTF surgery. Additional lid surgery was also recorded. The outcome was evaluated with perioperative OSD measurements and tear inflammatory mediators at baseline and one month and three months postoperatively. As a result, 42 patients (5 male, 37 female) underwent LTF surgery, and 13 patients received medial pretarsal support with collagen grafts. Eleven patients underwent blepharotomy, and 6 patients received Botox injections for upper lid retraction. The mean age of the participants was 46.4 years old, and the mean follow-up period was 10.6 months. Their clinical activity score (CAS) at the time of the operation was 2.1. Dry eye parameters, such as ocular surface disease index, tear breakup time, Schirmer’s I test score, and meibomian gland dropout were all significantly improved 3 months postoperatively. Tear osmolarity and inflammatory mediators in tear fluid, such as IL-6, IL-8, IL-18 and MCP-1, were also significantly improved after the procedures. After the surgery, all complications were mild and temporary. As a conclusion, LTF could provide TAO patients with both lid retraction correction and improvement of ocular surface disorders. Dry eye parameters significantly improved 3 months postoperatively. This method can serve as an alternative treatment option for lid correction in TAO patients.

LM22B-10 promotes corneal nerve regeneration through in vitro 3D co-culture model and in vivo corneal injury model

Corneal nerve wounding often causes abnormalities in the cornea and even blindness in severe cases. In this study, we construct a dorsal root ganglion-corneal stromal cell (DRG-CSC, DS) co-culture 3D model to explore the mechanism of corneal nerve regeneration. Firstly, this model consists of DRG collagen grafts sandwiched by orthogonally stacked and orderly arranged CSC-laden plastic compressed collagen. Nerve bundles extend into the entire corneal stroma within 14 days, and they also have orthogonal patterns. This nerve prevents CSCs from apoptosis in the serum withdrawal medium. The conditioned medium (CM) for CSCs in collagen scaffolds contains NT-3, IL-6, and other factors. Among them, NT-3 notably promotes the activation of ERK-CREB in the DRG, leading to the growth of nerve bundles, and IL-6 induces the upregulation of anti-apoptotic genes. Then, LM22B-10, an activator of the NT-3 receptor TrkB/TrkC, can also activate ERK-CREB to enhance nerve growth. After administering LM22B-10 eye drops to regular and diabetic mice with corneal wounding, LM22B-10 significantly improves the healing speed of the corneal epithelium, corneal sensitivity, and corneal nerve density. Overall, the DS co-culture model provides a promising platform and tools for the exploration of corneal physiological and pathological mechanisms, as well as the verification of drug effects in vitro. Meanwhile, we confirm that LM22B-10, as a non-peptide small molecule, has future potential in nerve wound repair. Statement of significanceThe cornea accounts for most of the refractive power of the eye. Corneal nerves play an important role in maintaining corneal homeostasis. Once the corneal nerves are damaged, the corneal epithelium and stroma develop lesions. However, the mechanism of the interaction between corneal nerves and corneal cells is still not fully understood. Here, we construct a corneal stroma-nerve co-culture in vitro model and reveal that NT-3 expressed by stromal cells promotes nerve growth by activating the ERK-CREB pathway in nerves. LM22B-10, an activator of NT-3 receptors, can also induce nerve growth in vitro. Moreover, it is used as eye drops to enhance corneal epithelial wound healing, corneal nerve sensitivity and density of nerve plexus in corneal nerve wounding model in vivo.

Contemporary Results with the Biosynthetic Glutaraldehyde Denatured Ovine Collagen Graft (Omniflow II) in Lower Extremity Arterial Revascularization in a Septic Context

Peripheral vascular graft infections are poorly-evaluated, despite high mortality and amputation rates. The vascular substitute of choice remains controversial when veins are unavailable. This study aims to evaluate the results of a biosynthetic collagen graft (Omniflow II®) in an infected field when autologous veins are unavailable. This retrospective, multicentric study included all consecutive patients in whom an Omniflow II graft was used for infra-inguinal revascularization in a septic context from January 2015 to January 2020. The primary end-point was freedom from major amputation; secondary end-points were 30-day mortality, survival, patency, and freedom from reinfection estimated using the Kaplan-Meier method. Twenty-nine patients (27 men, median age of 69years interquartile range IQR:60; 76) were included. Fever was present in 58.6%, a septic rupture in 17.9%, a pseudo-aneurysm in 25.0%. The 30-day mortality rate was 3.4%. Median follow-up reached 49months. At 1 and 3years, estimated freedom from major amputation was 88.4% and 83.9%, survival: 96%, primary patency: 74.6% and 65.8%, and reinfection free-survival: 85.6%. There were 7 occlusions (1 iliofemoral, 1 below-knee, and 5 above-knee bypasses), 3 explantations for persistent sepsis, 4 reinfections (all within 6months which led to 1 death and 3 out of 4 major amputations). The risk of major amputation increased with bypass reinfection (P=0.004), occlusion (P=0.005), and polymicrobial infection (P=0.05). In a septic context, the Omniflow II graft shows acceptable freedom from major amputation and reinfection. This usage remains outside the instructions of use, it is, therefore, is essential to pursue longer-term studies in larger cohorts.

Synthesis of a graft copolymer of polybutyl acrylate on fish collagen substratum using the RbTe1.5W0.5O6 complex oxide photocatalyst

In order to obtain a graft copolymer of polybutyl acrylate (PBA) on the substratum of emulsified fish collagen, RbTe1.5W0.5O6 complex oxide was used as a photocatalyst under visible light irradiation (λ = 400–700 nm). The emulsion was prepared by mixing the monomer and the aqueous collagen solution in a ratio of 1:2. Next, the catalyst was introduced into the resulting mixture, followed by stirring and ultrasound treatment. Before the reaction, the emulsion was bubbled with argon for 15 min. The reaction was carried out in an argon flow with continuous stirring. The radiation source was a 30 W visible light LED lamp placed at a distance of no more than 10 cm from the reaction mixture. At the end of the reaction, the emulsified organic phase was extracted with toluene, followed by phase isolation. In order to isolate the catalyst, the aqueous part of the solution was centrifuged for 30 min. Subsequently, the powder was repeatedly washed in distilled water at a temperature of 50 °C. The washed catalyst was dried, and the surface of the oxide after emulsion polymerization was examined using a scanning electron microscope. For the PBA–collagen graft copolymer emulsion isolated from the aqueous phase, molecular weight characteristics confirming the formation of a graft copolymer were obtained. It was established that the nitrogen content of amino acid residues in the PBA–collagen graft copolymer is significantly lower than in collagen, which indicates the formation of a graft copolymer. An analysis of films and sponges of PBA–collagen graft copolymer samples by scanning electron microscopy (SEM) showed a new structural-relief organization compared to collagen. A SEM analysis of the RbTe1.5W0.5O6 powder surface after the synthesis of the PBA–collagen graft copolymer detected fragments of polymer macromolecules on its surface. This can be explained by the fact that the catalyst used not only is a source of hydroxyl radicals, but сan also participate in the formation of a polymer on the powder surface due to the abstraction of a hydrogen atom from hydroxyl groups on its surface under the action of a hydroxyl radical.

Penile Extra-Tunical Graft Reconstruction of Peyronie's Disease Concavity Deformities

ABSTRACT Introduction The extra-tunical grafting (ETG) procedure was recently introduced by UCSF investigators as a tunica-sparing technique for management of penile concavity deformities. Objective We report our initial experience with the ETG procedure. Methods We retrospectively reviewed clinical records of patients who underwent ETG at our tertiary-care referral center between 2017-2020. A collagen graft made from bovine pericardium (Lyoplant®) was placed overlying the defect without violating the tunica albuginea or mobilizing the neurovascular bundle. The stretched penile length (SPL) and circumference at the location of deformity were measured intra-operatively. Patient reported outcomes including overall satisfaction, graft palpability, and change in erectile function were evaluated by an anonymous ten-question online survey. Results Nineteen men underwent ETG during the study period and had a median follow-up of 59 (IQR: 24 - 708) days. ETG was performed via either a window (15/19, 78.9%) or a de-gloving (4/19, 21.1%) incision with concomitant penile plication performed in 16/19 (84.2%) patients. Penile circumference increased by an average of 1.37 cm ± 0.53 (p = 0.03) at the location of deformity; pre- and post-operative SPL were similar (14.0 ± 1.4 vs. 14.0 ± 1.3 cm, p = 0.95). Fifteen patients (78.9%) responded to the online survey at an average of 240 days after surgery. Overall patient satisfaction was reported by 13/15 (86.7%) patients. Twelve out of 15 (80%) patients reported concavity deformity to be improved, with 73.3% reporting the deformity to be “much better” (Figure). One patient (5.3%) reported penile hypoesthesia/decrease in sensation. An improvement in erectile function was reported in 11/15 (73.3%) patients. Two of 15 (13.3%) patients noted no change in erectile function and 2/15 (13.3%) reported a decrease in erectile function. Of the 8 patients that had follow up greater than six months after surgery, graft palpability was reported in 4/8 (50%) patients but was not bothersome. Conclusions The ETG procedure appears to be safe and effective for the treatment of penile concavity deformities. Patient outcomes and satisfaction are favorable at intermediate follow-up. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Boston Scientific and Coloplast

Wound healing ability of acellular fish skin and bovine collagen grafts for split-thickness donor sites in burn patients: Characterization of acellular grafts and clinical application.

Due to its high polyunsaturated fatty acid content, acellular fish skin has emerged as a dermal substitute for the promotion of wound healing as it decreases scar formation while providing pain relief. However, various systematic studies on acellular fish skin, such as its biophysical analysis, in vitro activities, and clinical application, have not been sufficiently investigated. In this study, we conducted a comparative study to evaluate the wound-healing ability of acellular fish skin graft (Kerecis®) with that of the widely used bovine collagen skin graft (ProHeal®). The skin grafts were evaluated not only in terms of their biophysical properties, but also their in vitro cellular activities, using fibroblasts, keratinocytes, and human endothelial cells. The clinical study evaluated wound healing in 52 patients with acute burns who underwent skin grafting on donor sites from January 2019 to December 2020. The study was conducted with two groups; while only Kerecis® was tested in one group, Kerecis® and ProHeal® were compared in the other. In both groups, the application time of the dressing material was one to two days after split-thickness skin grafting to the donor sites. The Kerecis®-treatment group experienced faster healing than the other treatment group. In particular, the average wound healing time using the Kerecis® treatment and the ProHeal® treatment was 10.7±1.5days and 13.1±1.4days, respectively. We believe that the faster healing of the Kerecis® treatment, compared to that of the ProHeal® treatment, maybe due to the synergistic effect of the unique biophysical structure and the bioactive components of acellular fish skin.

Comparison of prognosis in two methods for the lingual nerve repair: direct suture with vein graft cuff and collagen allograft method

BackgroundNo studies have compared the outcomes of direct perineurial suture with vein graft cuff repair and indirect collagen allograft repair of the lingual nerve following an injury. Therefore, we evaluated and compared the outcomes of each over a 1-year observation period. We retrospectively assessed 20 patients who had undergone microneurosurgical repair of unilateral lingual nerve injuries at the Wakayama Medical University Hospital between May 2015 and March 2019. We utilized two different methods for lingual nerve repair, i.e., direct perineurial repair with a vein graft cuff and interpositional collagen allograft repair. Sensory and taste function in the lingual nerve were preoperatively evaluated using a static two-point discrimination test, superficial pain/tactile sensation test, tests for the pressure pain threshold (Semmens-Weinstein monofilament), test for thermal discrimination hot and cold sensation, and a taste discrimination test. These tests were performed again at 6 and 12 months postoperatively.ResultsCompared to the preoperative conditions, all patients showed improved sensory reactions. Functional sensory recovery outcomes were defined by Pogrel’s criteria, Medical Research Council Scale grades, and functional sensory recovery. In each group, all patients improved after the operation. However, the operation time was significantly shorter for an interpositional collagen allograft repair as compared to that for a direct perineurial repair with a vein graft cuff.ConclusionsThere were no statistically significant differences between the two repair Methods, except for the operation time. Both methods led to satisfactory results for all criteria. From an economic point of view, direct perineurial repair with a vein graft cuff is meaningful; however, the esthetic effect on the donor site should be considered. Conversely, interpositional collagen allograft repair has the advantage of a greatly shortened operation time.

A Novel Tenorrhaphy Suture Technique with Tissue Engineered Collagen Graft to Repair Large Tendon Defects

A Novel Tenorrhaphy Suture Technique with Tissue Engineered Collagen Graft to Repair Large Tendon Defects

A Novel Tenorrhaphy Suture Technique with Tissue Engineered Collagen Graft to Repair Large Tendon Defects.

Surgical management of large tendon defects with tendon grafts is challenging, as there are a finite number of sites where donors can be readily identified and used. Currently, this gap is filled with tendon auto-, allo-, xeno-, or artificial grafts, but clinical methods to secure them are not necessarily translatable to animals because of the scale. In order to evaluate new biomaterials or study a tendon graft made up of collagen type 1, we have developed a modified suture technique to help maintain the engineered tendon in alignment with the tendon ends. Mechanical properties of these grafts are inferior to the native tendon. To incorporate engineered tendon into clinically relevant models of loaded repair, a strategy was adopted to offload the tissue engineered tendon graft and allow for the maturation and integration of the engineered tendon in vivo until a mechanically sound neo-tendon was formed. We describe this technique using incorporation of the collagen type 1 tissue engineered tendon construct.

Functional outcome of two different grafting techniques in the surgical management of oral submucous fibrosis: a comparative evaluation.

To evaluate the functional efficacy of two different grafting techniques following the fibrotomy among subjects with oral submucous fibrosis (OSMF). Forty consecutively treated OSMF subjects between 20 and 40years who had grades 3 and 4a OSMF and mouth opening < 15mm were included in the present study. All the subjects were randomly divided into two groups. In Group I, all the subjects received a buccal pad of fat sandwiched with a nasolabial flap following fibrotomy. In contrast, Group II subjects received a buccal pad of fat combined with a collagen graft. The effect of two different surgical protocols on mouth opening was evaluated clinically before the surgery (T0) and 1month (T1), 6months (T2), and 12months (T3) after the surgery. In Group I subjects, the mouth opening increased significantly (P < 0.001) from 10.90 ± 1.971mm at T0 to 34.25 ± 3.127mm at T1, but reduced marginally to 32.15 ± 3.422mm at T2, and 31.30 ± 3.358mm at T3. In Group II, the mouth opening increased significantly (P < 0.001) from 10.85 ± 1.725mm at T0 to 28.90 ± 3.059mm, 29.10 ± 2.808mm, and 28.20 ± 2.285mm at T1, T2, and T3, respectively. At the end of 12months of follow-up, the mean value improvement in the mouth opening (T0-T3) was 20.4 ± 3.5mm and 17.3 ± 2.9mm in Groups I and II, respectively, and the difference was statistically significant (P = 0.006). The buccal pad of fat sandwiched with a nasolabial flap for the reconstruction following fibrotomy had a slightly better beneficial effect on the postoperative mouth opening among OSMF subjects.