In a new study, Iranian researchers found that a combination of laser therapy and stem cells could treat anal sphincter injuries and considerably control fecal incontinence (FI).
The anal sphincter is a circular muscle which provides both resting contractile tone and voluntary contraction for its role in closing the anal canal and maintaining fecal continence. Anal sphincter injury caused by trauma (e.g., during vaginal delivery) or surgical sphincterotomy can lead to fecal incontinence, a condition that affects women (about 9%) more than men (about 8%), and is associated with social isolation, low self-esteem and depression, and impaired quality of life.
Surgical repair of the anal sphincter has satisfactory short-term outcomes, but recurrence is common over the longer term. Other treatments such as artificial sphincters or mesh may carry complications including discomfort, infection, and implant failure. Bulking agents are also prone to displacement, emboli formation, and granulation. Therefore, the reconstitution of muscle tissue, utilizing stem cells that are capable of differentiating into various cell types, would appear an ideal strategy to improve long-term outcomes in FI.
In this regard, Iranian researchers in collaboration with a foreign university undertook a study using a combination of laser therapy and the use of adipose-derived stem cells to repair damages to the anal sphincter.
In this study, conducted by a research team of ten members from Iran University of Medical Sciences, Kurdistan University of Medical Sciences, Alborz University of Medical Sciences, and Hormozgan University of Medical Sciences, in collaboration with the University of Adelaide, Australia, the efficacy of the two treatments mentioned above, in recovery of the anal sphincter and its proper function after injury, was evaluated, both individually and simultaneously.
“Human adipose-derived stem cells (hADSCs) are an easily accessible and abundant source of the stem cells, with a high proliferative rate. The paracrine effect of hADSCs leads to anti-apoptotic, anti-inflammatory, anti-fibrotic and immunomodulatory, and angiogenesis properties that cause host tissue muscle regeneration”, has been reported by Mahmoud Yousefifard, the corresponding author and colleagues in the paper derived from this study. “On the other hand, their capability to differentiate into muscle fibers has been demonstrated in vitro”.
They’ve added: “A low-level laser (LLL) can activate these cells preparing the division phase and finally contributing to the muscular repair process. Furthermore, LLL has anti-apoptotic properties and can activate fibroblasts to FGF and IGF-1 secretion, contributing to the repair and regeneration of muscle tissue. Therefore, co-application of hADSCs and LLL may be an effective strategy for anal sphincter repair”.
To carry out this study, thirty-five male albino New Zealand rabbits weighing between 2.5 and 3 kg were obtained from the Pasteur Institute of Iran. These animals were then randomly divided into five equal groups as follows:
- Control group: animals received no intervention
- Sphincterotomy group: animals underwent sphincterotomy without any other intervention
- Laser group: animals underwent sphincterotomy and low-level laser irradiation
- hADSCs group: animals underwent sphincterotomy and hADSC injection into the injured anal sphincter
- Laser + hADSCs group: animals underwent sphincterotomy and hADSC injection into the injured anal sphincter followed by low-level laser irradiation
The results of the investigations showed that a combination of laser therapy and the use of hADSC stem cells could be more effective than any single method, causing muscle regeneration and angiogenesis, followed by improved sphincter condition and function.
“Results showed that the animals in the hADSCs + laser group showed a higher resting pressure in their sphincter than the other groups. Also, maximum squeeze pressure was better in all groups than animals under sphincterotomy, although this surgery was able to increase collagen content in the muscle. In addition, the combination of the two therapies mentioned in this study increased the expression of some genes that are effective in improving sphincter muscle status”, was mentioned by Yousefifard and colleagues.
They’ve said: “Our findings indicate that co-application of laser and hADSC therapy immediately after anal sphincter damage, could improve subsequent sphincter function. Moreover, combined therapy appears more effective for regaining resting anal pressure, and stimulating muscle regeneration and angiogenesis, than either laser or hADSCs alone”.
The findings, which are a new step in the treatment of problems related to fecal incontinence, have been published in the international journal, Stem Cell Research & Therapy. This journal is published by BioMed Central, a Springer Nature’s institute, with the last reported impact factor of 4.627.
Author: Mohammadreza Delfieh