Tissue-Engineered External Anal Sphincter Using Autologous Myogenic Satellite Cells and Extracellular Matrix: Functional and Histological Studies

• Published in: Annals of biomedical engineering 2016-05, Vol.44 (5), p.1773-1784
• Main Authors: Kajbafzadeh, Abdol-Mohammad, Kajbafzadeh, Majid, Sabetkish, Shabnam, Sabetkish, Nastaran, Tavangar, Seyyed Mohammad
• Format: Article
• Language: English
• Subjects: Anal Canal - metabolism; Anal Canal - pathology; Anal Canal - surgery; Animals; Biochemistry; Bioengineering; Biological and Medical Physics; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedicine; Biophysics; Bioprosthesis; Cells (biology); Cellular; Classical Mechanics; Disease Models, Animal; Extracellular Matrix - pathology; Extracellular Matrix - transplantation; Fecal Incontinence - metabolism; Fecal Incontinence - pathology; Fecal Incontinence - surgery; Female; Male; Muscles; Needles; Rabbits; Satellite Cells, Skeletal Muscle - metabolism; Satellite Cells, Skeletal Muscle - pathology; Scaffolds; Sterilization; Stimulation; Tissue Engineering - methods
• ISSN: 0090-6964; 1573-9686
• DOI: 10.1007/s10439-015-1468-3

The aim of the present study was to demonstrate the regaining histological characteristics of bioengineered external anal sphincters (EAS) in rabbit fecal incontinence model. The EAS of 16 rabbits were resected and decellularized. The decellularized scaffolds were transplanted to the terminal rectum following a period of 6 months of fecal incontinency (5 days after sterilization). The rabbits were divided into two groups: in group 1 ( n  = 8), myogenic satellite cells were injected into the transplanted sphincters. In group 2 ( n  = 8), the transplanted scaffolds remained in situ without cellular injection. The histological evaluation was performed with desmin, myosin, smooth muscle actin, CD31, and CD34 at 3-month intervals. The rabbits were followed for 2 years. Electromyography (EMG) with needle and electrical stimulation, pudendal and muscle electrical stimulation were also performed after 2 years of transplantation. At the time of biopsy, no evidence of inflammation or rejection was observed and the transplanted EAS appeared histologically and anatomically normal. The immunohistochemistry staining validated that the histological features of EAS was more satisfactory in group 1 in short-term follow-up. However, no statistically significant difference was detected between two groups in long-term follow-ups ( p value > 0.05). In both groups, grafted EAS contracted in response to electrical signals delivered to the muscle and the pudendal nerve. However, more signals were detected in group 1 in EMG evaluation. In conclusion, bioengineered EAS with myogenic satellite cells can gain more satisfactory histological outcomes in short-term follow-ups with better muscle electrical stimulation outcomes.