Rabbit Ear Cartilage Regeneration With a Small Intestinal Submucosa Graft

Comparison of porcine small intestinal submucosa and autologous graft material for repairing tympanic membrane perforation: a systematic review and meta-analysis

PURPOSE

To perform a systematic review and meta-analysis exploring the effectiveness of porcine small intestinal submucosa (pSIS) compared with autologous grafts for tympanic membrane perforation repair.

METHODS

A prospective meta-analysis protocol was registered on PROSPERO (International Prospective Register of Systematic Reviews) on June 5th, 2024, under protocol CRD42024551979. PubMed, Embase/Ovid and Cochrane Central databases were searched from inception to 28/05/2024 for studies comparing the use of pSIS versus autologous grafts (perichondrium, cartilage, temporalis fascia or cartilage-perichondrium) for tympanic membrane perforation repair. The outcomes evaluated were persistent perforation after surgery, operative time and hearing outcome. Statistical analyses were performed using the online Review Manager (Cochrane Collaboration). A subgroup analyses were carried out for the paediatric population.

RESULTS

We included 1,407 patients (1447 ears) from seven records; six retrospective cohort studies and one randomised controlled trial (RCT). pSIS graft was used in 563 ear surgeries (38.1%). Four studies included children with a mean age ranging from 7.3 to 11.7 years and the other 3 studies included adults with a mean age ranging from 30.8 to 48.4 years. Follow-up ranged from 2 to 132 months. There was no statistically significant difference in the failure rate (persistent perforation) between pSIS graft and autologous graft (RR 0.95; 95% CI 0.67-1.33; p = 0.76). However, reduced operative time was associated with using pSIS grafts (MD -16.12 min; 95% CI -22.94-9.31; p = < 0.00001).

CONCLUSION

Tympanic membrane perforation repair with pSIS grafts had a similar failure rate and hearing outcome compared to autologous grafts and demonstrated an association with reduced operative time.

Poly Lactic-co-Glycolic Acid Absorbable Plate Graft for Secondary Rhinoplasty in Asian Patients with Unilateral Cleft Lip Nose Deformity

INTRODUCTION

In secondary cleft lip and nasal deformity (CLND) correction, structural grafts are commonly used to control the nasal tip and restore the symmetry of the ala. However, the septal cartilage in Asians often weak and small. Biocompatible absorbable materials are alternatives to autologous grafts. This study assessed the surgical outcomes and complications of poly lactic-co-glycolic acid (PLGA) plate grafts in secondary CLND correction.

METHODS

This study was retrospectively analyzed for patients who underwent secondary rhinoplasty for unilateral CLND correction between March 2015 and November 2020. Using open rhinoplasty, the PLGA plate was grafted as a columellar strut. Clinical photographs taken at the initial (T0) and follow-up visits (T1: short-term, T2: long-term) were analyzed and anthropometric parameters, such as nostril height and width, dome height, and tip height, were measured.

RESULTS

Twenty-four patients were included in this study. The mean T1 and T2 periods were 1.0 ± 0.4 and 15.5 ± 3.1 months, respectively. The nostril height ratio increased from 0.78 ± 0.12 at T0 to 0.88 ± 0.08 at T1 and 0.86 ± 0.09 at T2 (p < 0.001; Relapse ratio -2.6 ± 6.7%). The tip height ratio increased from 0.60 ± 0.07 (T0) to 0.66 ± 0.05 (T2) (Relapse ratio -3.7 ± 3.0%).

CONCLUSIONS

The PLGA plate graft provided stable nasal tip projection and alar symmetry without major complications. It can be a good option for patients lacking available septal and concha cartilages or apprehensive of additional scarring.

Decellularization of Bovine Small Intestinal Submucosa

Decellularization technology promises to overcome some of the significant limitations in the regenerative medicine field by providing functional biocompatible grafts. The technique involves removal of the cells from the biological tissues or organs for further use in tissue engineering and clinical interventions. There are significant differences between decellularization protocols due to the intrinsic properties of different tissue types and purpose of use. This multistep, chemical-solution-based protocol is optimized for the preparation of decellularized bovine small intestinal submucosa (SIS).

Cartilage suspension using a poly (lactic-co-glycolic) acid system

BACKGROUND

This study aims to determine whether a bar-like implant made of poly lactic-co-glycolic acid (PLGA) could be used for cartilage suspension and whether the implant would be suitable for rhinoplasty.

METHODS

Three types of in vivo animal experiments were performed. First, the ear cartilage was incised in a full-thickness pattern, and the PLGA system was placed between the upper and lower cartilage to offer support to the tissue. Second, after the ear cartilage was forcibly bent, an implant was placed in the cartilage. For these rabbits, the outer aspect of the ear cartilage was assessed at 2, 4, 8, 10, and 12 weeks postoperatively. In addition, tissue samples were collected for histological evaluation 12 weeks after surgery. Third, the bar-like nasal implant was used for nasal septal suspension. We obtained micro-computed tomography (CT) images and evaluated the inflammatory reaction at 12 weeks postoperatively.

RESULTS

The results of both the ear suspension and bending retention tests revealed that the characteristic shapes of the cartilage were well preserved at 12 weeks postoperatively. Moreover, no abnormal inflammatory reaction was present in any site in the experimental group. We successfully implanted the bar-like nasal implant in the rabbit's septum, and no complications occurred. Furthermore, the physical examination and the micro-CT images did not reveal any nasal obstruction or inflammation.

CONCLUSIONS

We confirmed that an implant made of PLGA can be maintained in the cartilage tissue and believe that this can be applied in rhinoplasty as an alternative to autologous cartilage.

Porcine small intestinal submucosa (SIS) myringoplasty in children: A randomized controlled study

INTRODUCTION

A novel bioactive material for tissue graft, derived from porcine small intestinal mucosa (SIS) has been marketed. This material promotes early vessel growth, provides scaffolding for the remodeling tissues, and is inexpensive and ready-to-use. We evaluated efficacy, safety, and surgery time of SIS myringoplasty, in comparison with autologous temporalis fascia (PTF) repair in children in a prospective, two-group (SIS and PTF) randomized, blinded study at a tertiary-care pediatric institution.

MATERIALS AND METHODS

404 children with tympanic membrane (TM) repair were randomly assigned to receive SIS or PTF myringoplasty. Primary outcome was the healing of the TM at 6 months. Secondary outcomes were surgical time, and adverse events. Long-term follow-up ranging from 11 to 2 years was obtained in all enrolled children. Audiometric tests as pure-tone thresholds were applied in all patients. The Fisher's exact test and the Kriskal-Wallis test were applied for statistical analysis.

RESULTS AND DISCUSSIONS

Four-hundred-thirty-two TM perforations were treated, 217 in the SIS and 215 in the PTF groups. There were 209 stable TM closures in the SIS (96.3%) and 204 (94.8%) in the PTF arm. This difference was not statistically significant (odds ratio=0.4, 95%; confidence interval=0.12-1.41). SIS myringoplasty yielded reduced surgical time. No adverse reaction to SIS was encountered. Audiometric tests revealed no statistically significant difference in the two groups.

CONCLUSIONS

SIS myringoplasty is a safe and effective method for TM closure in children with reduced surgical time, as compared to PTF.

Acellular porcine intestinal submucosa as fascial graft in an animal model: Applications for revision tympanoplasty

OBJECTIVE: To demonstrate regeneration of muscle fascia appropriate for future harvest with the use of acellular porcine intestinal submucosa in a rat model.

STUDY DESIGN: Animal cohort study.

SETTING: Tertiary care academic medical center.

SUBJECTS AND METHODS: Sixteen male Sprague-Dawley rats underwent excision of rectus abdominis muscle fascia. A sheet of acellular porcine intestinal submucosa was placed in the fascia harvest defect. Graft and underlying muscle were harvested at three-, six-, and nine-week intervals. Histologic examination, including immunohistology for anti-von Willebrand factor, was performed at each timepoint. Additional selected specimens were subjected to latex vascular perfusion casts to examine vessel growth patterns within the graft.

RESULTS: Gross examination revealed a new tissue plane, indistinguishable from surrounding native fascia. Histology revealed an initial inflammatory response within the graft. Progressive influx of native tissue was noted over successive timepoints. Via collagen-specific staining, we noted progressive reorganization and maturation of the graft collagen matrix. At the final nine-week time point, a new loose connective tissue plane was reestablished between the graft and underlying muscle. Immunohistochemistry and latex perfusion both demonstrate an initial development of small capillaries that progresses over time to greater organization and arteriole formation.

CONCLUSION: Fascia regeneration may be possible with use of an acellular porcine intestinal submucosa graft in an animal model. Future studies may prove beneficial in restoring fascia in humans. Implications for potential advantages in tympanoplasty are discussed.

© 2010 American Academy of Otolaryngology-Head and Neck Surgery Foundation. All rights reserved.

Biphasic calcium phosphate to repair nasal septum: the first in vitro and in vivo study

Our objective was to evaluate the cytocompatibility and biocompatibility of biphasic calcium phosphate (BCP) in the nasal respiratory airway. In vitro, the attachment rate was quantified on BCP disks with normal human epithelial cells at 1, 3 and 24 h by determining N-acetyl beta-D-hexosaminidase activity. Proliferative activity of cells was indirectly assessed by MTT assay at 3, 9, 15 and 21 days. Plastic surfaces were used as positive control. In vivo, 15 rabbits underwent anterior nasal septum perforation and 10 septa were repaired with BCP disks. Five non-implanted animals were sacrificed at 3 months. Two groups of five implanted animals were sacrificed at 1 and 2 months. The surface of new airway mucosa covering BCP disks was evaluated macroscopically. During both steps, light microscopy, immunohistochemistry and scanning electron microscopy were performed. Statistical analysis was performed with the Mann-Whitney U-test. In vitro, at 1 and 3 h, the attachment rates were significantly better than on the plastic surface (p < 10(-2)). Mitochondrial activity increased on both surfaces but began 6 days later than on plastic. After 21 days of culture, cells were confluent and formed a monolayer covering the implant even in the bottom of the pores. In vivo, no perforations in the control group closed spontaneously. The mean rate of closure was 63% in the 1 month group and 64% in the 2 month group (p > 0.05). Implants were invaded by inflammatory reaction covered by incomplete differentiated respiratory epithelium. Throughout the study, all immunohistochemical findings remained positive. These data suggest a good affinity between BCP and nasal epithelial cells. BCP could be used to rebuild nasal septa.

Tissue engineering and cartilage regeneration for auricular reconstruction

OBJECTIVE

This paper will provide (a) a review on current status of auricular reconstruction (b) particularly focusing on the current data about pinna reconstruction using stem cells in combination with tissue engineering.

METHODS

The paper is divided into two sections. The first section presents a brief overview of the current status of auricular reconstruction. In the second section, the authors review the aspects and the current status of stem cells and tissue engineering researches related to cartilage regeneration.

CONCLUSIONS

Total auricular reconstruction represents one of the greatest challenges for the ENT and Facial Plastic surgeon. The matter of auricular cartilage reconstruction is complex, and progresses in material designs as well as in stem cells field are essential. Even if this bio-technology field is promising, the progresses still are not adequate as patient expectations remain high.