Amniotic Membrane and Its Anti Scarring Properties
What is Amniotic Membrane and how does it help?
Amniotic sac surrounds the fetus during the period of gestation and exhibits incredible antimicrobial, anti-inflammatory and anti-scarring characteristics1. The concept that the amniotic membrane could possibly be of value for the physicians in surgery and wound repair stems from its function during the whole period of pregnancy. It protects the baby from infection, rejection and helps nourish and sustain the fast growing fetus throughout its development. Amniotic membrane is usually discarded after the birth, headless that it contains properties that can prevent scar and adhesion development alongside other benefits.
Amniotic membrane is primarily composed of collagen fibers types I, III, IV, V and VII along with fibronectin and laminins. Furthermore amniotic membrane contains hyaluronic acid, which has been directly linked to having pro-inflammatory cells and properties that suppress T-cell activation2. Amniotic membrane has also been show promising results in stimulating healthy re-epithelization of damaged tissues.
Properties of amniotic membrane
Amniotic membrane possesses numerous properties that make it the best treatment options for use in various surgeries and healing treatments.
- It has bactericidal properties
- It contains many essential cytokines and growth factors
- It delays the time for wound healing
- It not elicit an immune reaction
- It reduced inflammation
- It reduces the formation of scar tissue and adhesions.
Indications
Amniotic membrane therapy has proven fruitful in the treatment of ocular diseases3, wound healing4, repair of tendons, ligaments and has shown promising results in reducing scar and adhesion formation5 when used in spinal and abdominal surgeries.
A paper published In the European Spine journal in 2009 explored the used of cross-linked amnion as an anti adhesive barrier for a laminectomy procedure in a canine model. The authors, Tao and fan reported that using amniotic membrane post laminectomy to re-cover the surgical site proved to be an effective anti-scar adhesion material. It can decrease the amount of scar and adhesion tenacity in the epidural space. Gross observation revealed that the amount of scar and adhesion tenacity of using cross-linked amnion were significantly low when compared to the group no treated with it. The Dura mater was covered with a white vascularized layer of amnion without a tenacious scar adhesion. Histology reports also showed reduced fibroblast migration and subsequently reduced epidural fibrosis in the group treated with the amniotic membrane. In conclusion using amniotic membrane post laminectomy proved to reduce the formation of scar and adhesion.6
Another study explored the use of Amniotic membrane wrap to reduce perineural adhesions in a rabbit model. In this study the ulnar nerves were dissected and then repaired. Amniotic membrane was wrapped around them and the models assessed after 3 month for the formation of perineural adhesions. Amniotic membrane wrapped nerves showed promising results, with significantly less perineural adhesion and fibrosis in comparison of the control. The study concluded that amniotic membrane use can reduce fibrosis and adhesion formation about sites of nerve repair.7 Another similar study conducted in New Zealand also found similar results when they used amniotic membrane wrap around damaged peripheral nerves. The group treated with the amniotic membrane showed better functional recovery in comparison to the control group.8
Apart from its use in Spinal surgery, it is also used for intra abdominal procedures with the same intent of reducing scar formation and adhesion. In a study conducted in 2011, amniotic membrane was used as anti scarring, anti adhesive intraperitoneal mesh coating on a rat model to be assessed for use in humans. The models were assessed after 7 to 17 days of the repair for scar and adhesion formation, neovascularization and tissue repair. The results revealed that all the models in the control group showed severe scarring and adhesion formation while those models treated with the amniotic membrane mesh coating showed marked reduction in scar formation.9
Amniotic membrane has shown promising results in reducing the formation of scars and adhesion in soft tissues as well. Scarring and adhesions are a leading cause of intestinal obstruction and infertility. In a study conducted to assess amniotic membrane use for the treatment of Gastroschisis which is a peritoneal defect in which the intestines are found outside the belly of the baby at birth. When compared to synthetic sources to close the defect, amniotic membrane showed about 0-3% area adhesion formation as compared to the synthetic sources which shows around 33% area adhesion formation. 10 Another study also demonstrated that using amniotic membrane graft after removing intra uterine adhesion reduced the recurrence of adhesion formation significantly as well as encouraged endometrial regeneration.11,12
In conclusion numerous studies have investigated using amniotic membrane to reduce scar and adhesion formation and have successfully demonstrated its efficacy and use in spinal and abdominal surgeries to reduce scar formation and adhesions.
References
- Inge E, Talmi YP, Sigler L, Finkelstein Y, Zohar Y. Antibacterial properties of human amniotic membranes. Placenta. 1991 May 1;12(3):285-8.
- He H, Li W, Tseng DY, Zhang S, Chen SY, Day AJ, Tseng SC. Biochemical characterization and function of complexes formed by hyaluronan and the heavy chains of inter-α-inhibitor (HC· HA) purified from extracts of human amniotic membrane. Journal of Biological Chemistry. 2009 Jul 24;284(30):20136-46.
- Shimazaki J, Aiba M, Goto E, Kato N, Shimmura S, Tsubota K. Transplantation of human limbal epithelium cultivated on amniotic membrane for the treatment of severe ocular surface disorders. Ophthalmology. 2002 Jul 31;109(7):1285-90.
- Castellanos G, Bernabé-García Á, Moraleda JM, Nicolás FJ. Amniotic membrane application for the healing of chronic wounds and ulcers. Placenta. 2017 Apr 10.
- Manuelpillai U, Moodley Y, Borlongan CV, Parolini O. Amniotic membrane and amniotic cells: potential therapeutic tools to combat tissue inflammation and fibrosis?. Placenta. 2011 Oct 31;32:S320-5.
- Tao H, Fan H. Implantation of amniotic membrane to reduce postlaminectomy epidural adhesions. European Spine Journal. 2009 Aug 1;18(8):1202-12.
- Kim SS, Sohn SK, Lee KY, Lee MJ, Roh MS, Kim CH. Use of human amniotic membrane wrap in reducing perineural adhesions in a rabbit model of ulnar nerve neurorrhaphy. Journal of Hand Surgery (European Volume). 2010 Mar;35(3):214-9.
- Henry FP, Goyal NA, David WS, Wes D, Bujold KE, Randolph MA, Winograd JM, Kochevar IE, Redmond RW. Improving electrophysiologic and histologic outcomes by photochemically sealing amnion to the peripheral nerve repair site. Surgery. 2009 Mar 31;145(3):313-21.
- Petter-Puchner, A.H., Fortelny, R.H., Mika, K., Hennerbichler, S., Redl, H. and Gabriel, C., 2011. Human vital amniotic membrane reduces adhesions in experimental intraperitoneal onlay mesh repair. Surgical endoscopy, 25(7), pp.2125-2131.
- Rennekampff HO, Dohrmann P, Föry R, Fandrich F. Evaluation of amniotic membrane as adhesion prophylaxis in a novel surgical gastroschisis model. Journal of Investigative Surgery. 1994 Jan 1;7(3):187-93.
- Amer MI, Abd-El-Maeboud KH, Abdelfatah I, Salama FA. Human amnion as a temporary biologic barrier after hysteroscopic lysis of severe intrauterine adhesions: pilot study. Journal of minimally invasive gynecology. 2010 Oct 31;17(5):605-11.
- Young RL, Cota J, Zund G, Mason BA, Wheeler JM. The use of an amniotic membrane graft to prevent postoperative adhesions. Fertility and sterility. 1991 Mar 31;55(3):624-8.