Adipose Tissue-Derived Regenerative Cell-Enhanced Lipofilling for Treatment of Cryptoglandular Fistulae-in-Ano: The ALFA Technique

Investigation of the Effect of High Shear Stress on Mesenchymal Stem Cells Using a Rotational Rheometer in a Small-Angle Cone-Plate Configuration

Within the healthy human body, cells reside within the physiological environment of a tissue compound. Here, they are subject to constant low levels of mechanical stress that can influence the growth and differentiation of the cells. The liposuction of adipose tissue and the subsequent isolation of mesenchymal stem/stromal cells (MSCs), for example, are procedures that induce a high level of mechanical shear stress. As MSCs play a central role in tissue regeneration by migrating into regenerating areas and driving regeneration through proliferation and tissue-specific differentiation, they are increasingly used in therapeutic applications. Consequently, there is a strong interest in investigating the effects of shear stress on MSCs. In this study, we present a set-up for applying high shear rates to cells based on a rotational rheometer with a small-angle cone-plate configuration. This set-up was used to investigate the effect of various shear stresses on human adipose-derived MSCs in suspension. The results of the study show that the viability of the cells remained unaffected up to 18.38 Pa for an exposure time of 5 min. However, it was observed that intense shear stress damaged the cells, with longer treatment durations increasing the percentage of cell debris.

Evaluating the quality of studies reporting on clinical applications of stromal vascular fraction: A systematic review and proposed reporting guidelines (CLINIC-STRA-SVF)

Background

The stromal vascular fraction (SVF) has been widely explored in a number of therapeutic applications in several specialties. Its therapeutic potential is being increasingly demonstrated, although its mechanism of action is still unclear.

Objective

To evaluate the quality of studies reporting on clinical applications of SVF.

Method

This is a systematic literature review that followed the PRISMA guidelines with the search of the studies from December 1, 2012, to December 1, 2022, in the following databases: MEDLINE, LILACS and EMBASE. The level of evidence of the studies was assessed using the GRADE system, and the rigor used in the publication of the results was assessed in relation to adherence to the guidelines indicated by the EQUATOR Network Group. The CLINIC - STRA-SVF reporting guideline was developed after the completion of this systematic review.

Results

A total of 538 articles were found, and 77 articles were selected after reading the titles and abstracts and removing duplicates. Then, 15 studies were removed for not meeting the inclusion criteria, leaving 62 studies. The CLINIC - STRA-SVF was developed and consists of 33 items and two tables.

Conclusion

There is scientific evidence, although mostly with a low level of evidence, that the use of SVF in clinical applications is safe and effective. The information published in these studies should be standardized, and the CLINIC - STRA-SVF reporting guideline proposed in this study may assist in the design, conduct, recording and reporting of clinical trials and others clinical studies involving the SVF.

Surgical management of complex perianal fistula revisited in a systematic review: a critical view of available scientific evidence

BACKGROUND

Treating complex perianal fistulas in Crohn's disease patients remains a challenge. Classical surgical treatments for Crohn's disease fistulas have been extrapolated from cryptoglandular fistulas treatment, which have different etiology, and this might interfere with its effectiveness, in addition, they increase fecal incontinence risk. Recently, new surgical techniques with support from biological approaches, like stem cells, have been developed to preserve the function of the sphincter. We have performed a systematic literature review to compare the results of these different techniques in the treatment of Crohn's or Cryptoglandular fistula.

METHODS

PubMed, EMBASE, Database of Abstracts of Reviews of Effectiveness, Cochrane Central Register of Controlled Trials were searched systematically for relevant articles. We included randomized controlled trials and observational studies that referred to humans, were written in English, included adults 18+ years old, and were published during the 10-year period from 2/01/2010 to 2/29/2020. Evidence level was assigned as designated by the Scottish Intercollegiate Guidelines Network.

RESULTS

Of the 577 citations screened, a total of 79 were ultimately included in our review. In Crohn's disease patients, classical techniques such as primarily seton, Ligation of Intersphincteric Fistula Tracks, or lay open, healing rates were approximately 50-60%, while in cryptoglandular fistula were around, 70-80% for setons or flaps. In Crohn's disease patients, new surgical techniques using derivatives of adipose tissue reported healing rates exceeding 70%, stem cells-treated patients achieved higher combined remission versus controls (56.3% vs 38.6%, p = 0.010), mesenchymal cells reported a healing rate of 80% at week 12. In patients with cryptoglandular fistulas, a healing rate of 70% using derivatives of adipose tissue or platelets was achieved, and a healing rate of 80% was achieved using laser technology. Fecal incontinence was improved after the use of autologous platelet growth factors and Nitinol Clips.

CONCLUSION

New surgical techniques showed better healing rates in Crohn's disease patients than classical techniques, which have better results in cryptoglandular fistula than in Crohn's disease. Healing rates for complex cryptoglandular fistulas were similar between the classic and new techniques, being the new techniques less invasive; the incontinence rate improved with the current techniques.

Minimally Invasive Treatment of Recurrent Anal Fistulas with Autologous Platelet-Rich Plasma Combined With Internal Orifice Closure

AIM

Minimally invasive procedures for the treatment of anal fistulas are gaining more and more popularity. For this purpose, Platelet-Rich Plasma (PRP) are administered to accelerate the healing process of various difficult wounds or lesions. The aim of this study was to evaluate preliminary results of PRP injection into the tissues adjacent to anal fistulas.

PATIENTS AND METHODS

A cohort of 42 patients with recurrent anal fistula, who underwent at least one cutting procedure previously, were enrolled into this preliminary and prospective trial. Closure of internal orifice was performed in all investigated patients, however, in 22 patients from group I, that procedure was combined with topical injection of PRP. In the postoperative period, the PRP administration could be repeated in case of incomplete fistula closure. Follow-up consisted of out-patient visits in a fortnight, 1, 2, and 12 months.

RESULTS

Complete closure of anal fistulas was achieved in 16 (75%) patients from group I and 10 (45,5%) patients from group II. The fistulas were healed in 9 patients from group I after single application of PRP. In the next 9 patients with incomplete fistula closure, the injection was repeated 2 to 4 times every fortnight leading finally to complete recovery in 6 of them.

CONCLUSIONS

Surgical fistula closure with local PRP application spares the anal sphincter and gives the opportunity to repeat the procedure several times if necessary. Treatment of recurrent anal fistulas with PRP can be considered as last resort therapy.

Mesenchymal Stem Cells for Cryptoglandular Anal Fistula: Current State of Art

Anal fistula is a common disease that needs surgical treatment to be resolved. Despite a variety of surgical options, the major problem is still to cure complex fistulas without any recurrence in the long-term follow-up but, at the same time, to avoid an impairment of continence. In recent years, one solution has been the application of mesenchymal stem cells derived from adipose tissue, especially in association with other treatments, such as the use of fibrin glue or the previous application of a seton. Their initial use in fistulas associated with Crohn's disease has shown encouraging results. In this non-systematic review our aim is to analyze the use in cryptoglandular fistulas: the rate of healing is not so high, and the number of studies is limited. Therefore, further randomized controlled trials are needed to establish their efficacy in the case of complex cryptoglandular anal fistulas and their possible complications.

Efficacy and safety of autologous adipose-derived stromal vascular fraction enriched with platelet-rich plasma in flap repair of transsphincteric cryptoglandular fistulas

Background

Transanal advancement flap repair of transsphincteric fistulas is a sphincter-preserving procedure, which frequently fails, probably due to ongoing inflammation in the remaining fistula tract. Adipose-derived stromal vascular fraction (SVF) has immunomodulatory properties promoting wound healing and suppressing inflammation. Platelet-rich plasma (PRP) reinforces this biological effect. The aim of this study was to evaluate the efficacy and safety of autologous adipose-derived SVF enriched with PRP in flap repair of transsphincteric cryptoglandular fistulas.

Methods

A prospective cohort study was conducted including consecutive patients with transsphincteric cryptoglandular fistula in a tertiary referral center. During flap repair, SVF was obtained by lipoharvesting and mechanical fractionation of adipose tissue and combined with PRP was injected around the internal opening and into the fistulous wall. Endpoints were fistula healing at clinical examination and fistula closure on postoperative magnetic resonance imaging (MRI). Adverse events were documented.

Results

Forty-five patients with transsphincteric cryptoglandular fistula were included (29 males, median age 44 years [range 36–53 years]). In the total study population, primary fistula healing was observed in 38 patients (84%). Among the 42 patients with intestinal continuity at time of surgery, primary fistula healing was observed in 35 patients (84%). In one patient, the fistula recurred, resulting in a long-term healing rate of 82%. MRI, performed in 37 patients, revealed complete closure of the fistula tract in 33 (89.2%). In the other patients, the tract was almost completely obliterated by scar tissue. During follow-up, none of these patients showed clinical signs of recurrence. The postoperative course was uneventful, except for three cases; venous thromboembolism in one patient and bleeding under the flap, necessitating intervention in two patients.

Conclusions

Addition of autologous SVF enriched with PRP during flap repair is feasible, safe and might improve outcomes in patients with a transsphincteric cryptoglandular fistula.

Trial registration

Dutch Trial Register, Trial Number: NL8416, https://www.trialregister.nl/

The clinical efficacy of stem cell therapy for complex perianal fistulas: a meta-analysis

BACKGROUND

Treatment of complex anal fistulas remains difficult. However, treatment with stem cells has had an encouraging success rate when applied to complex perianal fistulas. We systematically reviewed the current evidence through meta-analysis.

METHODS

We performed an electronic literature search on PubMed, Embase, and the Cochrane Library and identified studies (published between January 1946 and August 2017) that used stem cells to treat patients with complex perianal fistula. Each paper was evaluated for treatment success rate, target patients, types of stem cells used, number of cells used, and criteria for complete healing. Potential publication bias was assessed via visual inspection of a funnel plot and Orwin's fail-safe N. Out of 171 papers, 16 were included in the meta-analysis.

RESULTS

The overall healing rate of stem cell injection therapy for patients with complex perianal fistulas was 62.8% (95% CI 53.5-71.2, I² = 54.05%), whereas those for patients with Crohn's perianal fistulas alone and complex anal fistulas not associated with Crohn's disease were 64.1% and 61.5% (p = 0.840), respectively. Healing rates for autologous and allogenic stem cell treatment were 69.4% and 50.7% (p = 0.020), respectively. Four comparative studies out of 16 studies were analyzed separately. Stem cell therapy increased the healing rate compared to the control groups (OR 0.379, 95% CI 0.152-0.947).

CONCLUSIONS

Stem cell therapy is a good treatment option for complex perianal fistulas, which cannot be healed by conventional operative procedures. However, further research for additional supportive evidence, such as a large-scale randomized controlled trial, is required.

Permacol Collagen Paste Injection for Treatment of Complex Cryptoglandular Anal Fistulas: An Observational Cohort Study With a 2-Year Follow-up

BACKGROUND

Permacol paste injection is a novel treatment approach for complex cryptoglandular anal fistulas. This study was performed to evaluate the long-term clinical outcomes of treatment with Permacol paste for complex cryptoglandular fistulas.

METHODS

Patients with primary or recurrent complex cryptoglandular anal fistulas treated with Permacol paste from 2014 to 2016 were retrospectively analyzed.

RESULTS

A total of 46 patients (median age, 41.3 years; 21 female) underwent Permacol paste injection; 20 patients (43%) had previously undergone failed fistula surgery. The patients had experienced anal fistula-related symptoms for a median of 10 weeks (range, 3-50 weeks). All patients had a draining seton in situ for a median of 10 weeks (range, 4-46 weeks). The median follow-up time was 24 months (range, 1-25 months). At the 1-month follow-up, 2 patients had paste extrusion and 2 had anal abscesses. The mean preoperative Continence Grading Scale score was 1.10 ± 1.40, and that at 3 months postoperatively was 1.13 ± 1.39 ( P = .322). There was a significant difference in the preoperative and the 1- and 3-month postoperative pain scores ( P < .001). At the 24-month follow-up, the healing rate was 50% (n = 23). A total of 19 patients (41%) with a recurrent fistula after failed Permacol paste injection required additional operative procedures. The satisfaction rate at the 2-year follow-up was 65%.

CONCLUSION

Permacol paste injection is minimally invasive and technically easy to perform. It can be considered as a viable and reasonable option for the treatment of complex cryptoglandular anal fistulas in patients with fecal continence disorders.

The treatment of anal fistula: second ACPGBI Position Statement - 2018

It is over 10 years since the first ACPGBI Position Statement on the management of anal fistula was published in 2007. This second edition is the result of scrutiny of the literature published during this time; it updates the original Position Statement and reviews the published evidence surrounding treatments for anal fistula that have been developed since the original publication.

The Use of Stromal Vascular Fraction in the Treatment of Male Sexual Dysfunction: A Review of Preclinical and Clinical Studies

INTRODUCTION

Stem cell therapy using stromal vascular fraction (SVF) is a promising treatment modality. SVF is comprised of a mixture of adipose-derived stem cells, endothelial precursor cells, and immune modulatory cells that act synergistically to facilitate angiogenesis and epithelial cell differentiation. This makes SVF an attractive option for men's sexual disorders that require reconstitution of vasculature and endothelial lining, namely erectile dysfunction (ED) and Peyronie's disease (PD).

AIM

The objective of this study was to compare and contrast the available literature regarding the use of SVF in the treatment of male sexual dysfunction.

METHODS

A literature review was performed in PubMed with the keywords "stromal vascular fraction" and/or "erectile dysfunction" and/or "Peyronie's disease" and/or "sexual dysfunction."

MAIN OUTCOME MEASURES

The main outcome measure for preclinical studies was erectile function, as measured by changes in intracavernous pressures, and results of histopathologic analysis of corporal tissue. Clinical endpoint analysis in humans included various patient questionnaires.

RESULTS

For ED, there were 5 preclinical studies included in the analysis, with 1 Phase 1 clinical trial in humans. Major limitations of both the preclinical and clinical studies included the absence of SVF component analysis, and short duration of follow-up. Despite a paucity of preclinical studies, there was a single clinical study assessing the efficacy of combination SVF and shock wave therapy in the treatment of PD. Limitations of this study included an absence of a control group and the use of subjective data.

CONCLUSION

Preclinical and clinical data in the use of SVF for the treatment of male sexual dysfunction is deficient. Even though multiple medicinal disciplines are studying the use of SVF on a myriad of pathologies, further investigative work elucidating the mechanism and potential adverse effects of SVF need to be performed before clinical trials are undertaken. Haney NM, Gabrielson A, Kohn TP, Hellstrom WJG. The Use of Stromal Vascular Fraction in the Treatment of Male Sexual Dysfunction: A Review of Preclinical and Clinical Studies. Sex Med Rev 2019;7:313-320.

Wet milling of large quantities of human excision adipose tissue for the isolation of stromal vascular fraction cells

The isolation of stromal vascular fraction (SVF) cells from excised human adipose tissue, for clinical or research purposes, implies the tedious and time consuming process of manual mincing prior to enzymatic digestion. Since no efficient alternative technique to this current standard procedure has been proposed so far, the aim of this study was to test a milling procedure, using two simple, inexpensive and commercially available manual meat grinders, to process large amounts of adipose tissue. The procedure was assessed on adipose tissue resections from seven human donors and compared to manual mincing with scalpels. The processed adipose tissues were digested and the resulting SVF cells compared in terms of number, clonogenicity and differentiation capacity. After 10 min of processing, either device tested yielded on average sixfold more processed material for subsequent cell isolation than manual mincing. The isolation yield of SVF cells (isolated cells per ml of adipose tissue), their viability, phenotype, clonogenicity and osteogenic/adipogenic differentiation capacity, tested by production of mineralized matrix and lipid vacuoles, respectively, were comparable. This new method is practical and inexpensive and represents an efficient alternative to the current standard for large scale adipose tissue resection processing. A device based on the milling principle could be embedded within a streamlined system for isolation and clinical use of SVF cells from adipose tissue excision.

Surgical treatment of trans-sphincteric anal fistulas with the Fat GRAFT technique: a minimally invasive procedure

AIM

Anal fistulas are common pathologies with a significant social impact; however, their treatment is often complex and the recurrence rate can be significant. Some surgical treatments for fistula are also associated with the risk of sphincter injury. In this technical note, we aim to evaluate the feasibility and efficacy of the Fat GRAFT technique (Fat Grafting in Anal Fistula Treatment) in the treatment of recurrent anal fistulas.

METHOD

All patients presenting with recurrent trans-sphincteric anal fistulas over an 18-month period were included. After abdominal fat harvesting and fat preparation, fat grafting was performed in the track and peripheral area of the fistula. The internal and external openings of the fistula were closed to maximally preserve the retention of the adipocyte graft in the fistula.

RESULTS

Eleven patients underwent the Fat GRAFT procedure (seven men, four women). The average re-injected volume for each fistula was 21 ml (range 10-30 ml). The postoperative course was uneventful. At 6 months three patients developed recurrence (73% healed). There were no postoperative complications.

CONCLUSION

The Fat GRAFT technique appears to be a promising technique with a low risk of anal incontinence, in contrast to other techniques. This method was effective in > 70% of patients in a single session.

Adipose-derived stem cells: A novel source of parathyroid cells for treatment of hypoparathyroidism

Hypoparathyroidism is characterized by decreased function of the parathyroid glands with underproduction of parathyroid hormone (PTH), which can lead to low levels of calcium in the blood, often causing cramping and twitching of muscles or tetany, and several other symptoms. Severe hypocalcemia is a life-threatening condition. At present, both medical and surgical treatments are offered to improve the blood calcium, but they are not a cure. Adipose-derived stem cells (ADSCs), derived from the adipose tissue, are confirmed to be multipotent with adipogenic, chondrogenic, neurogenic, myogenic and osteogenic capabilities. Our hypothesis is that human ADSCs in culture can be differentiated into parathyroid cells, and used to reconstitute function.

Mechanical versus enzymatic isolation of stromal vascular fraction cells from adipose tissue

Clinical use of adipose-derived stem cells (ASCs) for a variety of indications is rapidly expanding in medicine. Most commonly, ASCs are isolated at the point of care from lipoaspirate tissue as the stromal vascular fraction (SVF). The cells are immediately administered to the patient as an injection or used to enrich fat grafts. Isolation of ASCs from adipose tissue is a relatively simple process performed routinely in cell biology laboratories, but isolation at the point of care for immediate clinical administration requires special methodology to prevent contamination, ensure integrity of clinical research and comply with regulatory requirements. A lack of practical laboratory experience, regulatory uncertainty and a relative paucity of objective published data can make selection of the optimum separation method for specific indications a difficult task for the clinician and can discourage clinical adoption. In this paper, we discuss the processes which can be used to separate SVF cells from fat tissue. We compare the various mechanical and enzymatic methods. We discuss the practical considerations involved in selecting an appropriate method from a clinical perspective. Studies consistently show that breakdown of the extracellular matrix achieved with proteolytic enzymes affords significantly greater efficiency to the separation process. SVF isolated through mechanical methods is equally safe, less costly and less time consuming but the product contains a higher frequency of blood mononuclear cells and fewer progenitor cells. Mechanical methods can provide a low cost, rapid and simple alternative to enzymatic isolation methods, and are attractive when smaller quantities of ASCs are sufficient.