A novel method for treatment of chronic anal fissure: adipose-derived regenerative cells - a pilot study

Non-enzymatic methods for isolation of stromal vascular fraction and adipose-derived stem cells: A systematic review

BACKGROUND

Adipose-derived stem cells (ADSCs) and the stromal vascular fraction (SVF) have garnered substantial interest in regenerative medicine due to their potential to treat a wide range of conditions. Traditional enzymatic methods for isolating these cells face challenges such as high costs, lengthy processing time, and regu-latory complexities.

AIM

This systematic review aimed to assess the efficacy and practicality of non-enzymatic, mechanical methods for isolating SVF and ADSCs, comparing these to conventional enzymatic approaches.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a comprehensive literature search was conducted across multiple databases. Studies were selected based on inclusion criteria focused on non-enzymatic isolation methods for SVF and ADSCs from adipose tissue. The risk of bias was assessed, and a qualitative synthesis of findings was performed due to the methodological heterogeneity of the included studies.

RESULTS

Nineteen studies met the inclusion criteria, highlighting various mechanical techniques such as centrifugation, vortexing, and ultrasonic cavitation. The review identified significant variability in cell yield and viability, and the integrity of isolated cells across different non-enzymatic methods compared to enzymatic procedures. Despite some advantages of mechanical methods, including reduced processing time and avoidance of enzymatic reagents, the evidence suggests a need for optimization to match the cell quality and therapeutic efficacy achievable with enzymatic isolation.

CONCLUSION

Non-enzymatic, mechanical methods offer a promising alternative to enzymatic isolation of SVF and ADSCs, potentially simplifying the isolation process and reducing regulatory hurdles. However, further research is necessary to standardize these techniques and ensure consistent, high-quality cell yields for clinical applications. The development of efficient, safe, and reproducible non-enzymatic isolation methods could significantly advance the field of regenerative medicine.

Comparison of botulinum toxin (BoNT) injection and lateral internal sphincterotomy (redo-LIS) for recurrent anal fissure treatment

Objective

Today's gold standard for treating chronic anal fissure is the Lateral Internal Sphincterotomy (LIS). Botulinum Toxin (BoNT) injection is, on the other hand, an alternative treatment for patients who do not want to have surgical treatment, patients undergoing chemotherapy, patients of high risk for surgery, and those who have the risk of anal incontinence (e.g., elderly, past anorectal surgery, vaginal multiple births, etc.). The aim of this study is to compare the effectiveness of BoNT and redo-LIS for treatment of post-LIS recurrent chronic anal fissure, and reveal differences if any.This study aims to compare redo-LIS and BoNT injection for treating post-LIS recurrent anal fissure.

Material and method

Nineteen patients who received LIS treatment and then redo-LIS or BoNT injection due to recurrence in the follow-up were included in this study. Group I (redo-LIS group) include 11 patients and group 2 (BoNT group) includes 8 patients. Their data on age, sex, anal incontinence scores and pain (VAS score) score as well.

Results

During the 3-month post-surgery follow-up period, there was statistically significant difference (p < 0.01) between groups by pain. No deterioration in the incontinence scores of patients in the group during the 6-month post-surgery period.

Conclusion

This study demonstrates that redo lateral internal sphincterotomy (LIS) is a reliable method for patients who received LIS but developed recurrent chronic anal fissure, and achieves successful results in terms of recurrence and relief of pain.

Application of nanofat for treatment of traumatic faecal incontinence after sphincteroplasty - A pilot study

AIM

The aim of this study was to investigate whether the application of nanofat containing stem cells improves continence in women who had previously undergone anal sphincteroplasty with unsatisfactory long-term outcomes.

METHOD

This prospective pilot study included nine women with various degrees of anal incontinence who had previously undergone anal sphincteroplasty due to obstetric trauma. In all patients, the Wexner Incontinence Score (WS) and Faecal Incontinence Quality of Life Score (FIQLS), as well as anal manometry and endoanal ultrasound measurements, were performed before the procedure and during follow-up. In all patients, liposuction was performed and 50 ml of raw lipoaspirate was obtained and processed using a NanoFat Kit device. Approximately 20 ml of the mechanically emulsified and filtrated fat was obtained and the anal sphincter complex was infiltrated with it. Patient follow-up was conducted in person or via telephone 6 and 12 months after the procedure.

RESULTS

The squeeze pressure was significantly increased 6 months after the procedure (p = 0.01). The external anal sphincter measured at the 12 o'clock position was significantly thicker (p = 0.04). A significant decrease in the WS was observed both 6 and 12 months after the procedure compared with baseline values (p < 0.05 for both).

CONCLUSION

This study is the first to show that the application of nanofat as an injectable product improves continence in patients with unsatisfactory results after sphincteroplasty, suggesting it to be a promising and effective therapeutic tool. The procedure is safe and can be easily performed as an ambulatory procedure.

Injection of freshly collected autologous adipose tissue in complicated pilonidal disease: a prospective pilot study

BACKGROUND

Pilonidal sinus disease (PSD) is a frequent disorder. Treatment failure and recurrence are common, leading to significant morbidity. The aim of this study was to investigate the impact and need for repeated treatment of injected autologous adipose tissue into non-healing PSD wounds and primary anal-near PSD or anal-near recurrence.

METHODS

At the Department of Surgery, Randers Regional Hospital, Denmark, a prospective pilot study was conducted on consecutive PSD patients with lack of healing 3 months after surgery (Bascom's cleft lift) or with primary or recurrent anal-near pilonidal sinus disease from December 2018 to March 2020. The primary endpoint was time to healing. Autologous adipose tissue was harvested from the patients and injected into the lesions after surgical revision. Patients were examined 2 and 12 weeks after surgery. Patients with lack of healing after 12 weeks (undermining or no skin coverage) were offered re-injection.

RESULTS

We included 30 patients [26 men and 4 women, median age 24 years (range 18-59 years)]. Complete healing was achieved in 25 patients [83.3%; 95% CI (69.9-96.7)]. Two patients had recurrence (6.7%). The median time to complete healing was 159 (189) days. The mean operation time was 70.6 ± 23.7 min and the mean amount of injected autologous adipose tissue was 19 ± 10 ml. There were no major complications.

CONCLUSION

Freshly collected autologous adipose tissue injected into chronic non-healing or primary and recurrent PSD lesions near the anal verge is safe and efficient.

Cell Therapy: Types, Regulation, and Clinical Benefits

Cell therapy practices date back to the 19th century and continue to expand on investigational and investment grounds. Cell therapy includes stem cell- and non-stem cell-based, unicellular and multicellular therapies, with different immunophenotypic profiles, isolation techniques, mechanisms of action, and regulatory levels. Following the steps of their predecessor cell therapies that have become established or commercialized, investigational and premarket approval-exempt cell therapies continue to provide patients with promising therapeutic benefits in different disease areas. In this review article, we delineate the vast types of cell therapy, including stem cell-based and non-stem cell-based cell therapies, and create the first-in-literature compilation of the different "multicellular" therapies used in clinical settings. Besides providing the nuts and bolts of FDA policies regulating their use, we discuss the benefits of cell therapies reported in 3 therapeutic areas-regenerative medicine, immune diseases, and cancer. Finally, we contemplate the recent attention shift toward combined therapy approaches, highlighting the factors that render multicellular therapies a more attractive option than their unicellular counterparts.

The application of regenerative medicine in colorectal surgery

Tissue reconstruction and regeneration represent one of the greatest challenges in any surgical field. Regenerative medicine combined with stem cell-based therapy is a novel and promising field of medicine. Stem cells possess the ability to differentiate into specialized cells and to decrease inflammation and therefore can play a role in repair or regeneration of damaged tissues. Colorectal surgery often deals with infected, poorly vascularized, radiated, and inflamed tissue, as well as instances where imperfect healing might have grave implications. This problem has led researchers to study utilizing stem cells in many colorectal conditions, such as anastomotic healing, perianal fistulae, rectovaginal fistulae, anal fissure, and fecal incontinence. The purpose of this review was to discuss prominent studies that explored stem cells utilization in treating different colorectal pathologies.

Anorectal Disorders: An Update

Anorectal disorders encompass structural, neuromuscular, and functional disorders. They are common, often distressing, and in some cases debilitating, and significantly add to the health care burden. They present with multiple, overlapping symptoms that can often obscure the underlying pathology and can pose significant diagnostic and management dilemmas. A meticulous history and comprehensive digital rectal examination can provide clarity on the diagnosis, appropriate testing, and management of these conditions. Today, with the development of sophisticated diagnostic tools such as high-resolution and high-definition (3-D) anorectal manometry, 3-D anal ultrasonography, magnetic resonance defecography and imaging, and neurophysiological tests such as translumbosacral anorectal magnetic stimulation, it is possible to more accurately define and characterize the underlying structural and functional abnormalities. In this review, we present a succinct update on the latest knowledge with regards to the pathophysiology, diagnosis and management of anal fissure, hemorrhoids, rectal prolapse, intussusception, rectocele, solitary rectal ulcer syndrome, levator ani syndrome, dyssynergic defecation and fecal incontinence.

Injection of freshly collected autologous adipose tissue into non-healing wounds after closed incision pilonidal surgery

BACKGROUND

Chronic non-healing wounds are a major problem after closed incision pilonidal surgery. Freshly collected autologous adipose tissue injected into perianal fistulas in patients with Crohn's disease seems to promote healing. We investigated this technique in patients with non-healing wounds after cleft-lift surgery for pilonidal sinus disease (PSD).

METHOD

In a prospective interventional pilot study conducted at our institution autologous adipose tissue from the abdominal wall was harvested, and injected into chronic non-healing PS wounds after surgical revision, healing rate being the primary outcome. The wounds were left open. Patients were followed every 2 to 3 weeks until complete healing (skin coverage, no undermining).

RESULTS

7 male patients were included (mean age 24 ± 0,6 SD years) and complete healing was achieved in 6 patients (86%). Median time to healing was 90 days (range 36-403 days ) and mean follow-up time was 388± 45 days. All patients reported major symptom relief shortly after the procedure. The mean operation time was 80 ± 23 minutes and the mean amount of freshly collected adipose tissue injected was 27.4± 12 ml. There were no complications.

CONCLUSIONS

Freshly collected autologous adipose tissue injected into chronic non-healing pilonidal wounds seems safe and efficient.

Adipose tissue-derived regenerative cells improve implantation of fertilized eggs in thin endometrium

Aim: Embryo implantation and subsequent pregnancy depends on endometrial thickness. To investigate potential fertility strategies for women with thin endometrium, we explored the efficacy of adipose tissue-derived regenerative cells (ADRCs) on thin endometrium and embryo implantation in a mouse model. Materials & methods: ADRCs isolated from mouse subcutaneous fat were characterized by flow cytometry. Endometrium thickness, endometrial fibrosis, embryo implantation and angiogenesis factors were evaluated in uterine cavities of ethanol-induced thin endometrium mice with ADRC transplantation. Results: ADRCs included adipose-derived stem cells and some blood vessel component cells. ADRCs improved endometrial thickness, endometrial fibrosis and embryo implantation and augmented vascular endothelial growth factor expression in the mouse uterine. Conclusion: ADRCs may be a useful therapeutic strategy to improve fertility of women with thin endometrium.

Intraoperative Strategies for Minimal Manipulation of Autologous Adipose Tissue for Cell- and Tissue-Based Therapies: Concise Review

The stromal vascular fraction (SVF) is a heterogeneous population of stem/stromal cells isolated from perivascular and extracellular matrix (ECM) of adipose tissue complex (ATC). Administration of SVF holds a strong therapeutic potential for regenerative and wound healing medicine applications aimed at functional restoration of tissues damaged by injuries or chronic diseases. SVF is commonly divided into cellular stromal vascular fraction (cSVF) and tissue stromal vascular fraction (tSVF). Cellular SVF is obtained from ATC by collagenase digestion, incubation/isolation, and pelletized by centrifugation. Enzymatic disaggregation may alter the relevant biological characteristics of adipose tissue, while providing release of complex, multiattachment of cell-to-cell and cell-to-matrix, effectively eliminating the bioactive ECM and periadventitial attachments. In many countries, the isolation of cellular elements is considered as a "more than minimal" manipulation, and is most often limited to controlled clinical trials and subject to regulatory review. Several alternative, nonenzymatic methods of adipose tissue processing have been developed to obtain via minimal mechanical manipulation an autologous tSVF product intended for delivery, reducing the procedure duration, lowering production costs, decreasing regulatory burden, and shortening the translation into the clinical setting. Ideally, these procedures might allow for the integration of harvesting and processing of adipose tissue for ease of injection, in a single procedure utilizing a nonexpanded cellular product at the point of care, while permitting intraoperative autologous cellular and tissue-based therapies. Here, we review and discuss the options, advantages, and limitations of the major strategies alternative to enzymatic processing currently developed for minimal manipulation of adipose tissue. Stem Cells Translational Medicine 2019;8:1265&1271.

Stromal vascular fraction technologies and clinical applications

Introduction: The heterogeneous pool of cells found in the stromal vascular fraction of adipose tissue (SVF) and the purified mesenchymal stromal/stem cells (ASCs) isolated from this pool have increasingly been used as therapeutic tools in regenerative medicine.Areas covered: As SVF and ASCs are different, and should be used in different manners according to various clinical and biological indications, we reviewed the current literature, and focused on the clinical use of SVF to appraise the main medical fields for development. Both enzymatic digestion and mechanical disruption have been used to obtain SVF for non-homologous use. The safety and/or benefits of SVF have been examined in 71 clinical studies in various contexts, mainly musculoskeletal conditions, wound healing, urogenital, and cardiovascular and respiratory diseases. The use of SVF as a therapy remains experimental, with few clinical trials.Expert opinion: SVF provides a cellular and molecular microenvironment for regulation of ASC' activities under different clinical conditions. SVF may enhance angiogenesis and neovascularization in wound healing, urogenital and cardiovascular diseases. In joint conditions, therapeutic benefits may rely on paracrine immune-modulatory and anti-inflammatory mechanisms. Novel point of care methods are emerging to refine SVF in ways that meet the regulatory requirements for minimal manipulation.

Functional and histologic effects after implanting pluripotent stem cells in a murine model with sphincterotomy

INTRODUCTION AND AIMS

Fecal incontinence is a disabling condition with devastating consequences for the patients. Medical and surgical options are not very satisfactory, reason by which regenerative medicine has been considered in this field. In the present research, we analyzed functional and histologic effects after implanting pluripotent stem cells (PSCs) in a murine model with sphincterotomy.

MATERIALS AND METHODS

Female Wistar rats were subjected to sphincterotomy and divided into three groups. Group 1 (control group) was treated with 300μL of balanced saline solution and group 2 (late treatment) and group 3 (early treatment) received 50,000 PSCs resuspended in 300μL of balanced saline solution. All animals were evaluated through high-resolution anorectal manometry 24hours before and after sphincterotomy and every month for three months. Finally, the rats were euthanized and histopathologic sections from the anal canal were obtained.

RESULTS

All groups showed a decrease in resting anal pressure and squeeze anal pressure 24hours after sphincterotomy. At the third month, higher anal pressures in the groups treated with PSCs were detected. Regarding the histologic effects, the microscopic architecture was restored and there was a significant decrease in the inflammatory response in the groups treated with PSCs.

CONCLUSION

PSCs implantation improves anal tone, as well as histologic structure, presenting better regenerative results when implanted as early treatment.

Treatment algorithm for anal fissure. Consensus document of the Spanish Association of Coloproctology and the Coloproctology Division of the Spanish Association of Surgeons

The Spanish Association of Coloproctology and the Coloproctology Division of the Spanish Association of Surgeons propose this consensus document with a treatment algorithm for anal fissure that could be used for decision making. Non-surgical therapy and surgical treatment of anal fissure are explained, and the recommended algorithm is provided. The methodology used was: creation of a group of experts; search in PubMed, MEDLINE and the Cochrane Library for publications from the last 10 years about anal fissure; presentation at the 21st National Meeting of the Spanish Association of Coloproctology Foundation 2017 with voting for/against each conclusion by the attendees and review by the scientific committee of the Spanish Association of Coloproctology.