Micro-fragmented adipose tissue injection for the treatment of complex anal fistula: a pilot study accessing safety and feasibility

Cell-assisted lipotransfer in treating uncontrollable sepsis associated perianal fistula: a pilot study

PURPOSE

Surgeons can treat debilitating conditions of uncontrollable complex anorectal fistulas with sepsis, even after repeated fistula surgeries, for curative intention. Adipose-derived stem cells have shown good outcomes for refractory Crohn fistula. Unfortunately, cell therapy has some limitations, including high costs. We have therefore attempted immediate cell-assisted lipotransfer (CAL) in treating refractory complex anal fistulas and observed its outcomes.

METHODS

In a retrospective study, CAL, using a mixture of freshly extracted autologous stromal vascular fraction (SVF) and fat tissues, was used to treat 22 patients of refractory complex anal fistula from March 2018 to May 2021. Preoperative and postoperative assessments were performed with direct visual inspection, digital palpation, and endoanal ultrasonography. A fistula was considered completely healed if (1) the patient had no symptoms of discharge or inflammation; (2) there were no visible secondary openings of fistula tract inside and outside of the anorectal unit and even in the perineum; and (3) there was no primary opening in the anus. The endpoint of complete remission was wound healing without signs of inflammation 3 months after CAL treatment.

RESULTS

In a total of 22 patients who received CAL treatment, 19 patients showed complete remission, 1 patient showed partial improvement, and 2 patients showed no improvement. One of the 2 patients without improvement at primary endpoint showed complete remission 9 months after CAL. There were no significant adverse effects of the procedure.

CONCLUSION

We found that the immediately-collected CAL procedure for refractory complex anal fistula showed good outcomes without adverse side effects. It can be strongly recommended as an alternative surgical option for the treatment of complex anal fistula that is uncontrollable even after repeated surgical procedures. However, considering the unpredictable characteristics of SVF, long-term follow-up is necessary.

Autologous micro-fragmented adipose tissue injection provides significant and prolonged clinical improvement in patients with knee osteoarthritis: a case-series study

PURPOSE

Among the conservative strategies to manage patients with symptomatic knee osteoarthritis (OA), an innovative approach exploiting the regenerative capability of adipose tissue and its resident MSCs (Mesenchymal Stem Cells or Medicinal Signalling Cells) has been proposed with encouraging results. This study aims to demonstrate the benefits of autologous micro-fragmented adipose tissue (MAT) injection in the conservative treatment of knee osteoarthritis and whether any variables may affect the outcome. This is a case series single-centre study in which patients underwent intraarticular MAT injection without any associated procedures.

METHODS

Based on inclusion and exclusion criteria, 49 patients (67 Knees) were included and retrospectively analysed with a mean follow-up of 34.04 ± 13.62 months (minimum 11 - maximum 59). Patients were assessed through the WOMAC and KOOS questionnaires at baseline (pre-treatment) and 1-, 3-, 6-, 12-, 24- and 36-month follow-up. A minimal clinically important difference (MCID) of at least 7.5 points for the WOMAC pain scale and 7.2 for the WOMAC function scale compared to the baseline value was used.

RESULTS

WOMAC and KOOS scores improved after treatment compared to baseline at all follow-ups with p < 0.001. Male gender and Kellgren-Lawrence (KL) grade 2 were associated with smaller improvement in WOMAC and KOOS scores (with respect to females and to KL grade 1, respectively) up to 24 months. The percentage of patients who reach the MCID for WOMAC pain is generally lower than that of patients who reach the MCID for WOMAC function (around 80% at all time points), but it increases significantly over time. Moreover, the baseline score of the WOMAC pain and function influence the outcome. Patients with worse symptoms are more likely to reach the MCID.

CONCLUSIONS

Intra-articular knee injection of MAT for the treatment of knee osteoarthritis (KOA), recalcitrant to traditional conservative treatments, proved to be effective in a high percentage of cases. The positive association between a worse pre-operative score and a better clinical response to the treatment would support the idea that intra-articular administration of MAT could be considered in patients with very symptomatic KOA in which joint-replacement surgeries are not indicated (or accepted).

LEVEL OF EVIDENCE

IV, case series.

Efficacy of Injection of Freshly Collected Autologous Adipose Tissue Into Complex Cryptoglandular Anal Fistulas

BACKGROUND

Treatment of cryptoglandular anal fistulas with injection of autologous or allogenic adipose tissue-derived mesenchymal stem cells has shown promising results. However, allogenic adipose tissue-derived mesenchymal stem cells are expensive and use of autologous adipose tissue-derived mesenchymal stem cells requires preceding liposuction and isolation of stem cells, time for cell culture, and laboratory facilities. Freshly collected autologous adipose tissue may be an easily available and inexpensive alternative.

OBJECTIVE

This study aimed to investigate the efficacy of injection with freshly collected autologous adipose tissue into complex cryptoglandular anal fistulas.

DESIGN

Prospective cohort study.

SETTING

Single tertiary center for treatment of cryptoglandular fistulas in Denmark.

PATIENTS

This study included 77 patients with complex cryptoglandular anal fistulas.

INTERVENTIONS

The intervention included injections of freshly collected autologous adipose tissue. Patients not achieving healing after 8 to 12 weeks were offered a second injection.

MAIN OUTCOME MEASURES

Primary outcome was fistula healing defined as no symptoms of discharge and no visible external and palpable internal opening by anorectal digital examination at clinical evaluation 6 months after final treatment. Secondary end points were combined clinical and MRI fistula healing, reduced fistula secretion and anal discomfort, and complications to the treatment.

RESULTS

Thirty-nine patients (51%) achieved the primary outcome of fistula healing 6 months after their final treatment. Nine patients (12%) experienced reduced secretion and decreased anal discomfort. Thirty-seven patients (48%) achieved combined clinical and MRI fistula healing. Treatment was well tolerated; 5 patients (4%) experienced serious adverse events (infection or bleeding) requiring surgical intervention.

LIMITATIONS

No control group was included.

CONCLUSION

Injection of freshly collected autologous adipose tissue is a safe treatment of complex cryptoglandular anal fistulas and may be an easily accessible inexpensive alternative to cultured autologous and allogenic adipose tissue-derived mesenchymal stem cells. See Video Abstract at http://links.lww.com/DCR/C45 .

EFICACIA DE LA INYECCIN DE TEJIDO ADIPOSO AUTLOGO RECIN RECOLECTADO EN FSTULAS ANALES CRIPTOGLANDULARES COMPLEJAS

ANTECEDENTES:El tratamiento de las fístulas anales criptoglandulares con inyección de células madre mesenquimales derivadas de tejido adiposo autólogo o alogénico ha mostrado resultados prometedores. Sin embargo, las células madre mesenquimales derivadas de tejido adiposo alogénicas son costosas y el uso de células madre mesenquimales derivadas de tejido adiposo autólogas requiere una liposucción previa y el aislamiento de las células madre, tiempo para el cultivo celular e instalaciones de laboratorio. El tejido adiposo autólogo recién recolectado puede ser una alternativa económica y de fácil acceso.OBJETIVO:Investigar la eficacia de la inyección con tejido adiposo autólogo recién recolectado en fístulas anales criptoglandulares complejas.DISEÑO:Estudio de cohorte prospectivo.ESCENARIO:Centro terciario para el tratamiento de fístulas criptoglandulares en Dinamarca.PACIENTES:Setenta y siete pacientes con fístulas anales criptoglandulares complejas.INTERVENCIONES:Inyecciones de tejido adiposo autólogo recién recolectado. A los pacientes que no lograron la curación después de 8 a 12 semanas se les ofreció una segunda inyección.MEDIDAS DE RESULTADO PRINCIPALES:El resultado primario fue la cicatrización de la fístula definida como ausencia de síntomas de secreción, apertura externa visible e interna palpable mediante examen digital anorrectal en la evaluación clínica 6 meses después del tratamiento final. Los resultados secundarios fueron la combinación clínica y de curación en la resonancia magnética, la reducción de la secreción de la fístula y las molestias anales, y las complicaciones del tratamiento.RESULTADOS:Treinta y nueve pacientes (51%) lograron el resultado primario de curación de la fístula 6 meses después de su tratamiento final. Nueve pacientes (12%) experimentaron una reducción de la secreción y una disminución de las molestias anales. Treinta y siete pacientes (48%) lograron la curación combinada de la fístula clínica y en la resonancia magnética. El tratamiento fue bien tolerado; 5 pacientes (4%) experimentaron eventos adversos graves (infección o sangrado) que requirieron intervención quirúrgica.LIMITACIONES:No se incluyó ningún grupo de control.CONCLUSIÓN:La inyección de tejido adiposo autólogo recién recolectado es un tratamiento seguro de las fístulas anales criptoglandulares complejas y puede ser una alternativa económica de fácil acceso a las células madre mesenquimales derivadas de tejido adiposo autólogo y alogénico cultivadas. Consulte Video Resumen en http://links.lww.com/DCR/Cxx . (Traducción-Dr. Felipe Bellolio ).

Autologous Adipose-Derived Tissue Stromal Vascular Fraction (AD-tSVF) for Knee Osteoarthritis

Adipose tissue contains adult mesenchymal stem cells that may modulate the metabolism when applied to other tissues. Stromal vascular fraction (SVF) can be isolated from adipose tissue mechanically and/or enzymatically. SVF was recently used to decrease the pain and improve the function of knee osteoarthritis (OA) patients. Primary and/or secondary OA causes inflammation and degeneration in joints, and regenerative approaches that may modify the natural course of the disease are limited. SVF may modulate inflammation and initiate regeneration in joint tissues by initiating a paracrine effect. Chemokines released from SVF may slow down degeneration and stimulate regeneration in joints. In this review, we overviewed articular joint cartilage structures and functions, OA, and macro-, micro-, and nano-fat isolation techniques. Mechanic and enzymatic SVF processing techniques were summarized. Clinical outcomes of adipose tissue derived tissue SVF (AD-tSVF) were evaluated. Medical devices that can mechanically isolate AD-tSVF were listed, and publications referring to such devices were summarized. Recent review manuscripts were also systematically evaluated and included. Transferring adipose tissues and cells has its roots in plastic, reconstructive, and aesthetic surgery. Micro- and nano-fat is also transferred to other organs and tissues to stimulate regeneration as it contains regenerative cells. Minimal manipulation of the adipose tissue is recently preferred to isolate the regenerative cells without disrupting them from their natural environment. The number of patients in the follow-up studies are recently increasing. The duration of follow up is also increasing with favorable outcomes from the short- to mid-term. There are however variations for mean age and the severity of knee OA patients between studies. Positive outcomes are related to the higher number of cells in the AD-tSVF. Repetition of injections and concomitant treatments such as combining the AD-tSVF with platelet rich plasma or hyaluronan are not solidified. Good results were obtained when combined with arthroscopic debridement and micro- or nano-fracture techniques for small-sized cartilage defects. The optimum pressure applied to the tissues and cells during filtration and purification of the AD-tSVF is not specified yet. Quantitative monitoring of articular joint cartilage regeneration by ultrasound, MR, and synovial fluid analysis as well as with second-look arthroscopy could improve our current knowledge on AD-tSVF treatment in knee OA. AD-tSVF isolation techniques and technologies have the potential to improve knee OA treatment. The duration of centrifugation, filtration, washing, and purification should however be standardized. Using gravity-only for isolation and filtration could be a reasonable approach to avoid possible complications of other methodologies.

Comparison of the Diagnostic Accuracy of Percutaneous Fistula Contrast-Enhanced Ultrasound Combined with Transrectal 360° 3-D Imaging and Conventional Transrectal Ultrasound in Complex Anal Fistula

This study compared the diagnostic accuracy of percutaneous fistula contrast-enhanced ultrasound (CEUS) combined with 360° 3-D transrectal ultrasound (TRUS) imaging (CEUS + 360°-TRUS) with that of conventional transrectal ultrasound in the diagnosis of complex anal fistulas. A total of 156 patients clinically diagnosed with complex anal fistula from January 2020 to December 2021 were studied and randomly divided into an experimental group (n = 82) and a control group (n = 74). Patients in the experimental group were examined by percutaneous fistula CEUS combined with CEUS + 360°-TRUS, while patients in the control group were examined using TRUS. The detection of fistulas (main tract, branch and internal orifice) and the accuracy of Parks classification were compared between the two groups. Recurrences were followed up at 1, 3 and 6 mo after the surgery. A total of 156 patients were included, aged 23-68 y (average: 37.7 ± 18.2 y). In both groups, the course of disease was &lt;1 mo in 128 cases, 1-2 mo in 22 cases and &gt;3 mo in 6 cases. A total of 474 fistulas were confirmed by surgery in the aforementioned patients, including 224 main fistulas, 250 branch pipes and 254 internal orifices. The CEUS + 360°-TRUS group had 96.87%, 90.41% and 90.14% diagnostic accuracy for the main tract, branch and internal orifice, which was statistically significant (p &lt; 0.001) compared with the 85.00%, 70.00% and 72.46% for the TRUS group, respectively. The overall accuracy of Parks classification of anal fistula in the CEUS + 360°-TRUS group was significantly higher than that in the TRUS group (90.24% vs. 78.38%, p &lt; 0.001). After 6 mo of follow-up, the recurrence rate in the CEUS + 360°-TRUS group was 4.87%, and the recurrence rate in the TRUS group was 18.91%. Percutaneous fistula CEUS combined with transrectal 360° 3-D imaging has significantly higher accuracy than conventional TRUS in the diagnosis of complex anal fistula, especially for anal fistula branches, internal openings and Parks classification and is beneficial in reducing post-operative occurrence of complex anal fistulas.

Modified nanofat grafting: Stromal vascular fraction simple and efficient mechanical isolation technique and perspectives in clinical recellularization applications

Background: Nanofat grafting (NG) is a simple and cost-effective method of lipoaspirates with inter-syringe passages, to produce stromal vascular fraction (SVF) and isolate adipose-derived stem cells (ASCs). This represents a tremendous interest in the future clinical needs of tissue engineering. In this study, we optimized the NG technique to increase the yield of ASC extractions.

Methods: We analyzed three groups of SVF obtained by 20, 30, and 40 inter-syringe passages. The control group was an SVF obtained by enzymatic digestion with Celase. We studied their cell composition by flow cytometry, observed their architecture by confocal microscopy, and observed immunomodulatory properties of the ASCs from each of the SVFs by measuring inflammatory markers of macrophages obtained by an ASC monocyte co-culture.

Results: We have established the first cell mapping of the stromal vascular fraction of adipose tissue. The results showed that SVF obtained by 20 inter-syringe passages contains more statistically significant total cells, more cells expressing the ASC phenotype, more endothelial cells, and produces more CFU-F than the SVF obtained by 30 and 40 passages and by enzymatic digestion. Confocal microscopy showed the presence of residual adipocytes in SVF obtained by inter-syringe passages but not by enzymatic digestion. The functional study indicates an orientation toward a more anti-inflammatory profile and homogenization of their immunomodulatory properties.

Conclusion: This study places mechanically dissociated SVF in the center of approaches to easily extract ASCs and a wide variety and number of other progenitor cells, immediately available in a clinical setting to provide both the amount and quality of cells required for decellularized tissues.

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.

Trends in Treatment for Hemorrhoids, Fistula, and Anal Fissure: Go Along the Current Trends

Recent trends in benign anal disease treatment are minimizing surgery to preserve normal anorectal anatomical unit and its functions. However, some surgeons still prefer and are confident with the use of conventional solid surgical methods. In this report, we will investigate the recent trends in the treatment for hemorrhoids, fistula, and anal fissure. The practice guidelines of advanced countries, including UK, Italy, France, USA, Japan, and ESCP, are referred to in this review. Opinions suggested in international meetings were also added. In the management of hemorrhoids, surgical treatments and office procedures were recommended according to a patient's status and preference. For the management of complex anal fistula, novel sphincter-preserving surgical techniques are more widely accepted than a sphincter-dividing procedure of immediate repair following fistulectomy. The treatment of anal fissures is well covered in the guidelines of the ASCRS.

The Value of Transrectal Ultrasound in the Preoperative Diagnosis of Complex Anal Fistula (CAF): Based on a Retrospective Cohort Study

Objective

A case-control study was employed to retrospectively analyze the value of transrectal ultrasound in the preoperative diagnosis of complex anal fistula (CAF).

Methods

The clinical data of 128 patients with CAF treated in our hospital from March 2019 to June 2021 were analyzed retrospectively. All patients were examined by transrectal ultrasound and MRI with Hitachi HI Vision Ascendus ultrasound diagnostic apparatus and MRI. The general data of the patients (age, sex, course of disease, complications, and previous operation history) and ultrasonic image characteristics were recorded. The consistency of internal orifice, head, branch/abscess, and abscess detected by ultrasound, MRI, and ultrasound combined with MRI were compared, and the sensitivity, accuracy, and specificity of ultrasound, MRI, and the combination of ultrasound and MRI (ultrasound+MRI) in the diagnosis of different Parks classification of anal fistula (AF) were compared.

Results

The ultrasound images of the rectal probe in typical cases were compared with the MRI images. The characteristics of the ultrasound images were as follows: the outer orifice of AF was a thin strip of mixed echo or low echo leading to the skin side, and the inner orifice showed local dilated low echo, mixed echo, or interruption of mucosal continuity. The following are the MRI image features: abnormal long bar signal shadow from the dorsal side of the end of the coccyx to the S5 plane, low signal on T1WI, high signal on T2WI, blurred boundary, uneven signal, bifurcation in the lower end of the tail for "Y" shape, one branch opening at the body surface at about 6 o'clock, the other walking horizontally, passing through the levator ani muscle to the right posterior position of the rectum at about 6:00 o'clock, and penetrating the inner mouth of the rectum at 6 o'clock. The detection of internal orifice, head, branch/abscess, and abscess were compared by three examination methods. There was significant difference in the detection rate of internal orifice and branch/purulent cavity among the three methods (P < 0.05). The detection rates of internal mouth and branch/abscess cavity by ultrasound and MRI (94.77% and 94.94%) were higher than those by single ultrasound (75.16% and 79.78%) and MRI (81.05% and 83.15%) (P < 0.05). There was no significant difference in the detection rate of ultrasound, MRI internal orifice, and branch/purulent cavity (P > 0.05). There was no significant difference in the detection rate of supervisor and abscess among the three methods (P > 0.05). The results of operation included transsphincter type (n = 53), intersphincter type (n = 45), and superior sphincter type (n = 30). Analysis of transsphincter type AF detected by three methods: 42 cases of transsphincter type AF and 86 cases of nonsphincter type AF were detected by ultrasound, 36 cases of transsphincter type AF and 92 cases of nontranssphincter type AF were detected by MRI, 57 cases of transsphincter type AF and 71 cases of nonsphincter type AF were detected by ultrasound and MRI. The comparison of the efficacy of the three methods in the diagnosis of transsphincter AF and the sensitivity of the three methods in the diagnosis of transsphincter AF showed significant difference (P < 0.05). The sensitivity of ultrasound and MRI in the diagnosis of transsphincter AF (96.23%) was higher than those of single ultrasound (67.92%) and MRI (64.15%) (P < 0.05). There was no significant difference in the accuracy and specificity of the three methods in the diagnosis of transsphincter AF (P > 0.05). There were 41 cases of intersphincter type AF and 87 cases of nonsphincter type AF detected by ultrasound, 38 cases of intersphincter type AF and 90 cases of nonsphincter intersphincter type AF detected by MRI, and 45 cases of intersphincter type AF and 83 cases of nonsphincter intersphincter type AF detected by ultrasound and MRI. The sensitivity and accuracy of the three methods in the diagnosis of intersphincter AF were statistically significant (P < 0.05). The sensitivity and accuracy (100.00% and 100.00%) of ultrasound and MRI in the diagnosis of intersphincter AF were higher than those of single ultrasound (66.67% and 79.69%) and MRI (71.11% and 85.16%) (P < 0.05). There was no significant difference in the specificity of the three methods in the diagnosis of intersphincter AF (P > 0.05). The results of three methods were compared, including 24 cases of superior sphincter type AF and 89 cases of nonsuperior sphincter type AF, 21 cases of superior sphincter type AF, and 107 cases of nonsuperior sphincter type AF detected by MRI and 93 cases of superior sphincter type AF and 128cases of nonsuperior sphincter type AF detected by ultrasound and MRI. There was no significant difference in the sensitivity, accuracy, and specificity of the three methods in the diagnosis of superior sphincter AF (P > 0.05).

Conclusion

The sphincter, anorectal, and surrounding tissues were clearly demonstrated by transrectal ultrasound. The internal orifice, head, branch/abscess, abscess, and the relationship between abscess and sphincter in the diagnosis of CAF were in good agreement with the surgical results. Ultrasound+MRI can take into account the advantages of ultrasound and MRI, make up for each other, and improve the detection rate of internal orifice and branch/abscess. It can improve the sensitivity of diagnosis of transsphincter AF and the sensitivity and accuracy of intersphincter AF, which can provide intuitive and valuable imaging information for surgical intervention.

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.

Ligation of Intersphincteric Fistula Tract (LIFT) with or Without Injection of Bone Marrow Mononuclear Cells in the Treatment of Trans-sphincteric Anal Fistula: a Randomized Controlled Trial

BACKGROUND

Ligation of intersphincteric fistula tract (LIFT) is a sphincter-saving procedure used for treatment of complex anal fistula. The current study aimed to assess the outcome of local injection of bone marrow mononuclear cells (BM-MNCs) in conjunction with LIFT as compared to LIFT alone in regards to healing rate, time to healing, and ultimate success rate.

METHODS

This was a prospective randomized trial on patients with trans-sphincteric anal fistula. Patients were randomly allocated to one of two equal groups: LIFT and LIFT with BM-MNC injection. The main outcome measures were healing at 10 weeks of follow-up, recurrence after healing, and complications.

RESULTS

Seventy patients (48 male and 22 female) of a mean age of 37.9 ± 10.4 years were included. The mean time to complete healing after LIFT + BM-MNCs was significantly shorter than after LIFT alone (20.5 ± 5.2 vs 28.04 ± 5.8 days; P < 0.0001). The ultimate success rates of both groups were similar (LIFT = 60% vs LIFT with BM-MNCs = 68.6%, P = 0.62). There was no significant difference in the mean operation time or complication rate between the two groups. Secondary extension and previous anal surgery were significant independent predictors of failure of healing.

CONCLUSION

LIFT combined with BM-MNC injection was associated with a shorter time to complete healing than LIFT alone. However, BM-MNC injection did not have a significant impact on the overall healing and ultimate success rate.

Molecular differences of adipose-derived mesenchymal stem cells between non-responders and responders in treatment of transphincteric perianal fistulas

Background

Injection of autologous adipose tissue (AT) has recently been demonstrated to be an effective and safe treatment for anal fistulas. AT mesenchymal stem cells (AT-MSCs) mediate the healing process, but the relationship between molecular characteristics of AT-MSCs of the injected AT and fistula healing has not been adequately studied. Thus we aimed to characterize the molecular and functional properties of AT-MSCs isolated from autologous AT injected as a treatment of cryptogenic high transsphincteric perianal fistulas and correlate these findings to the healing process.

Methods

27 patients (age 45 ± 2 years) diagnosed with perianal fistula were enrolled in the study and treated with autologous AT injected around the anal fistula tract. AT-MSCs were isolated for cellular and molecular analyses. The fistula healing was evaluated by MRI scanning after 6 months of treatment. AT-MSC phenotype was compared between responders and non-responders with respect to fistula healing.

Results

52% of all patients exhibited clinical healing of the fistulas as evaluated 6 months after last injection. Cultured AT-MSCs in the responder group had a lower short-term proliferation rate and higher osteoblast differentiation potential compared to non-responder AT-MSCs. On the other hand, adipocyte differentiation potential of AT-MSCs was higher in non-responder group. Interestingly, AT-MSCs of responders exhibited lower expression of inflammatory and senescence associated genes such as IL1B, NFKB, CDKN2A, TPB3,TGFB1.

Conclusion

Our data suggest that cellular quality of the injected AT-MSCs including cell proliferation, differentiation capacity and secretion of proinflammatory molecules may provide a possible mechanism underlying fistula healing. Furthermore, these biomarkers may be useful to predict a positive fistula healing outcome.

Trial registration: NTC04834609, Registered 6 April 2021. https://clinicaltrials.gov/ct2/show/NCT04834609

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02644-8.

In Vitro Characterization of Canine Microfragmented Adipose Tissue Non-Enzymatically Extracted from the Thigh and Lumbar Regions

Simple Summary

Mesenchymal stem cells are located in bone marrow, adipose tissue, synovial membrane, and muscular tissue. They have an immunosuppressive, anti-inflammatory, and antifibrotic effect. Tissue engineering considers the usage of mesenchymal stem cells as a possible option for regenerating tissues, with respect to bone and cartilage, due to their ability to differentiate into multiple cytotypes (including chondrocytes and osteoblasts). Herein, we characterize a non-invasive solution based on Rigenera^® technology, a mechanical disaggregation method able to produce autologous adipose tissue-derived micrografts which are analogous to adipose-derived stem cells.

Abstract

Within the adult canine population, disabilities and symptoms including joint pain and functional impairment are commonly observed in articular cartilage lesions and present a challenging feat in the operating room. Clinical settings require less invasive and more minimally manipulated measures facilitated by innovative and advanced technology. Mesenchymal stem cells have recently been proposed and, furthermore, autologous adipose tissue administration via injection has emerged as a new albeit somewhat controversial therapeutic tool. The purpose of this study is to characterize canine autologous micro-fragmented adipose tissue (micrografts) by mechanical approach without substantial manipulations. Adipose tissue samples collected from six dogs were processed by a Rigenera device and by enzymatic digestion from two different body regions (lumbar and thigh region). Interestingly, the immunophenotypic analysis attested that cells from Rigenera^® were highly positive for the mesenchymal stem cells markers CD73 and CD90, less positive for hematopoietic CD45 and CD34, and negative for MHC class II antibodies (which play a role in immune responses). Finally, the Rigenera^® technology obtained micrografts with a 35% higher expression of the IL10 gene with relevant anti-inflammatory activities compared to the enzymatic digestion protocol. This evidence suggests a potential improved clinical outcome capable of modulating inflammation and immune responses.

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/

Efficacy and Safety of Treatment of Complex Idiopathic Fistula-in-Ano Using Autologous Centrifuged Adipose Tissue Containing Progenitor Cells: A Randomized Controlled Trial

BACKGROUND

Mesenchymal stem cells derived from adipose tissue have been successfully used to promote sphincter-saving anal fistula healing.

OBJECTIVE

The aim of this study was to evaluate the efficacy and safety of the use of autologous centrifuged adipose tissue in the healing process of cryptoglandular complex anal fistulas.

DESIGN

This is a randomized controlled trial.

SETTINGS

This study was conducted at a single center.

PATIENTS

Patients with complex perianal fistulas not associated with Crohn's disease were included. Rectovaginal fistulas were not included.

INTERVENTIONS

Patients were randomly allocated to receive treatment with centrifuged adipose tissue injection (experimental group) and without injection (control group) in combination with fistula surgery.

MAIN OUTCOME MEASURES

The primary outcome was defined as the proportion of patients with complete fistula closure at 4 weeks (short-term outcome) and 6 months after surgery (long-term outcome). Healing was defined as when the external opening was closed with no perianal discharge on clinical assessment. The secondary outcome was safety that was evaluated by the analysis of adverse events up to 3 months after surgery. Pelvic MRI was performed at 3 months to assure safety and the accuracy of the clinical determination of healing. Postoperative pain, return to work/daily activities, persistent closure at 6 months, fecal incontinence, and patient satisfaction were evaluated.

RESULTS

Fifty-eight patients who received centrifuged adipose tissue injection and 58 patients who did not receive centrifuged adipose tissue injection were included in the safety and efficacy analysis. After 4 weeks, the healing rate was 63.8% in the experimental group compared with 15.5% in the control group (p < 0.001). No major adverse events were recorded. Postoperative anal pain was significantly lower in the injection group. Time taken to return to work/daily activities was significantly shorter in the experimental group (3 days) than in the control group (17 days). At 6 months, persistent closure was similar in the 2 groups (86.2% vs 81%). Fecal Incontinence Score at 6 months after surgery was identical to the preoperative score. Patient satisfaction was high in both groups.

LIMITATIONS

The absence of blinding, the lack of correlation between stem cell content, and the clinical outcome were limitations of the study.

CONCLUSIONS

Autologous centrifuged adipose tissue injection may represent a safe, efficacious, and inexpensive option for the treatment of complex fistula-in-ano. See Video Abstract at http://links.lww.com/DCR/B607.

CLINICAL TRIALS REGISTRATION

URL: https://www.clinicaltrials.gov. Identifier: NCT04326907.

EFICACIA Y SEGURIDAD DEL TRATAMIENTO DE LA FSTULA ANAL COMPLEJA IDIOPTICA UTILIZANDO TEJIDO ADIPOSO CENTRIFUGADO AUTLOGO QUE CONTIENE CLULAS PROGENITORAS UN ENSAYO CONTROLADO ALEATORIO

ANTECEDENTES:Las células madre mesenquimales derivadas del tejido adiposo se han utilizado con éxito para promover la curación de la fístula anal con preservación de esfínter.OBJETIVO:El objetivo de este estudio fue evaluar la eficacia y seguridad del uso de tejido adiposo autólogo centrifugado en el proceso de cicatrización de fístulas anales complejas de origen criptoglandular.DISEÑO:Ensayo controlado aleatorio.ENTORNO CLÍNICO:Estudio unicéntrico.PACIENTES:Se incluyeron pacientes con fístulas perianales complejas no asociadas a Enfermedad de Crohn. No se incluyeron las fístulas rectovaginales.INTERVENCIONES:Los pacientes fueron asignados aleatoriamente para recibir tratamiento con inyección de tejido adiposo centrifugado (grupo experimental) y sin inyección (grupo de control) en combinación con cirugía de fístula.PRINCIPALES MEDIDAS DE VALORACIÓN:El resultado primario se definió como la proporción de pacientes con cierre completo de la fístula a las 4 semanas (resultado a corto plazo) y 6 meses después de la cirugía (resultado a largo plazo). La curación se definió cuando orificio externo se cerró sin secreción perianal en la valoración clínica. El resultado secundario fue la seguridad que se evaluó mediante el análisis de los eventos adversos (EA) hasta 3 meses después de la cirugía. La resonancia magnética pélvica se realizó a los 3 meses para garantizar la seguridad y la precisión clínica de la curación. Se evaluó el dolor postoperatorio, el regreso al trabajo / actividades diarias, el cierre persistente a los 6 meses, la incontinencia fecal y la satisfacción del paciente.RESULTADOS:Cincuenta y ocho pacientes que recibieron inyección de tejido adiposo centrifugado y 58 pacientes que no recibieron inyección de tejido adiposo centrifugado se incluyeron en el análisis de seguridad y eficacia. Después de 4 semanas, la tasa de curación fue del 63,8% en el grupo experimental en comparación con el 15,5% en el grupo de control (p <0,001). No se registraron eventos adversos importantes. El dolor anal posoperatorio fue significativamente menor en el grupo de inyección. El tiempo necesario para volver al trabajo / actividades diarias fue significativamente menor en el grupo experimental (3 días) con respecto al grupo de control (17 días). A los 6 meses, el cierre persistente fue similar en los dos grupos (86,2% vs 81%). La puntuación de incontinencia fecal a los 6 meses después de la cirugía fue idéntica a la puntuación preoperatoria. La satisfacción del paciente fue muy alta en ambos grupos.LIMITACIONES:Ausencia de cegamiento, falta de correlación entre el contenido de células madre y el resultado clínico.CONCLUSIONES:La inyección de tejido adiposo centrifugado autólogo puede representar una opción segura, eficaz y económica para el tratamiento de la fístula anal compleja.Registro de ensayos clínicos: www.clinicaltrials.gov, identificador NCT04326907; No patrocinado.Consulte Video Resumen en http://links.lww.com/DCR/B607.

Effectiveness of infliximab treatment of complex idiopathic anal fistulas

OBJECTIVES

To investigate the effects of infliximab treatment in patients with complex idiopathic anal fistulas refractory to standard surgical treatment.

MATERIALS AND METHODS

We retrospectively evaluated the effects ofinfliximab treatmentin patients with complex idiopathic anal fistulas refractory to standard surgical intervention. The primary outcome was achievement of substantial clinical improvement defined as sustained, reduced inflammatory activity at perioperativeevaluation, i.e., only minimal-to-moderate secretion and induration and a reduction of fistula size of a magnitude that would make it possible to perform a lay-open or sphincter-sparring closure procedure. Secondary outcomes weresymptom improvement, adverse treatment events and fistula healing after the surgical procedure in those achieving the primary outcome.

RESULTS

Twenty-two patients were included (18 high transsphincteric, 3complex low transsphincteric, 1 suprasphincteric fistula). Fistulas had been present for a median of 24 [interquartile range, IQR: 12-33] months. In total, 16 patients (73%) achieved the primary outcome of substantial clinical improvement. Median time from infliximab initiation to patients achieved the primary outcome was 11 [IQR: 8-22] months. Sixteen of the patients responding to infliximab received subsequent lay-open or sphincter-sparring closure procedure surgery. Of these, ten (63%) achieved fistula healing. No serious infectious complications to infliximab treatment were seen. One patient developed a new abscess. One patient developed psoriasis (pustolosispalmoplantaris).

CONCLUSIONS

Infliximab treatment may be considered a supplement to repeated curettage and setondrainage in the management of selected, complex idiopathic anal fistulas. Such combined treatment may make otherwise refractory fistulas amenable to definitive closure attempts.

Regenerative medicine approaches for the management of respiratory tract fistulas

Respiratory tract fistulas (or fistulae) are abnormal communications between the respiratory system and the digestive tract or the adjacent organs. The origin can be congenital or, more frequently, iatrogenic and the clinical presentation is heterogeneous. Respiratory tract fistulas can lead to severely reduced health-related quality of life and short survival. Therapy mainly relies on endoscopic surgical interventions but patients often require prolonged hospitalization and may develop complications. Therefore, more conservative regenerative medicine approaches, mainly based on lipotransfer, have also been investigated. Adipose tissue can be delivered either as unprocessed tissue, or after enzymatic treatment to derive the cellular stromal vascular fraction. In the current narrative review, we provide an overview of the main tissue/cell-based clinical studies for the management of various types of respiratory tract fistulas or injuries. Clinical experience is limited, as most of the studies were performed on a small number of patients. Albeit a conclusive proof of efficacy cannot be drawn, the reviewed studies suggest that grafting of adipose tissue-derived material may represent a minimally invasive and conservative treatment option, alternative to more aggressive surgical procedures. Knowledge on safety and tolerability acquired in prior studies can lead to the design of future, larger trials that may exploit innovative procedures for tissue processing to further improve the clinical outcome.

CELL THERAPY IN INFLAMMATORY BOWEL DISEASE

In recent years, cell-based therapies have been explored in various immune-mediated inflammatory diseases, including inflammatory bowel disease (IBD). Cell therapy is the process of introducing new cells into an organism or tissue in order to treat a disease. The most studied cellular treatment in IBD was "stem cells-based therapy", which was explored according to different protocols in terms of type of donors, stem cells sources, study design and clinical endpoints. More recently, preliminary studies have also described the clinical use of "regulatory cells", which include T-reg and Tr1 cells, and "tolerogenic" dendritic cells. Finally, induced pluripotent stem cells are the subject of an intensive preclinical research program on animal models, including those related to colitis.

Expanding Clinical Indications of Mechanically Isolated Stromal Vascular Fraction: A Systematic Review

BACKGROUND

Mechanically isolated stromal vascular fraction (tSVF, tissue SVF) is a potent regenerative solution, increasingly used as a therapeutic modality for a variety of pathologies. With recent evidence conclusively favoring mechanical isolation over enzymatic alternatives, the therapeutic share and indications of tSVF are expected to grow even further.

OBJECTIVES

The aim of this study was to provide a systematic review of all studies reporting on the use of tSVF.

METHODS

A systematic search was undertaken of the Embase, PubMed, Web of Science, and Cochrane Central Register of Controlled Trials databases. Outcome measures included clinical indications, such as recipient area, adverse events, clinical results recipient area, method of application, follow-up duration and evaluation methods.

RESULTS

Of the total of 4505 articles identified, 186 full-texts were screened. Thirty-four studies, reporting on 1443 patients were included. tSVF-based therapy was observed for 10 different pathologies, including aged skin (8 studies), scars (5), wounds (6), osteoarthritis (6), tendinopathy (2), temporomandibular joint disorders (1), androgenic alopecia (1), perianal fistula (3), migraine (1), and vocal fold scarring (1). Across all studies, tSVF-based therapy resulted in favorable clinical results. Overall, 50 (3.43%) minor and one (0.07%) major adverse events were observed, mainly related to the liposuction procedure.

CONCLUSIONS

tSVF offers a safe, easy and legal treatment modality for a range of indications. Future research is indicated to identify the optimal isolation protocol, dose and timing. In addition, basic research remains crucial to identify the mechanism of action of SVF within different pathologies.

LEVEL OF EVIDENCE: 4

Comparative technical analysis of lipoaspirate mechanical processing devices

Fat grafting is a well-established procedure in reconstructive, aesthetic, and regenerative medicine, in particular due to the presence in the adipose tissue of a high concentration of mesenchymal stem cells. The need to reduce fat processing times, for an immediate clinical use and regulatory restrictions on the degree of manipulation of human tissues, has led to the development of numerous devices for the mechanical, nonenzymatic processing of adipose tissue. The aim of this study is to describe the state of the art of mechanical devices used for fat processing, performing a technical analysis of the currently commercially available devices. This should facilitate the development of new devices that improve therapeutic results.

Refractory Complex Crohn's Perianal Fistulas: A Role for Autologous Microfragmented Adipose Tissue Injection

BACKGROUND

Complex perianal fistulas represent one of the most challenging manifestations of Crohn's disease. Combined surgical and medical therapy with biologic drugs today represent the first-line treatment option, but its efficacy does not exceed 60%. Recently, new therapeutic approaches, such as the use of mesenchymal stromal cells, have shown promising results. The adipose tissue is an abundant and easy to access source. The effectiveness, safety, and feasibility of local injections of microfragmented adipose tissue in patients with refractory complex fistulizing perianal Crohn's disease (PCD) were evaluated.

METHODS

Fifteen patients with persistent complex fistulizing PCD after biosurgical approach and subsequent surgical "rescue" repair were treated in S. Orsola-Malpighi Hospital with a single-local administration of microfragmented adipose tissue prepared using a minimal manipulation technique (Lipogems) in a closed system. Clinical outcomes were determined at 24-week follow-ups assessing success rate, defined as combined clinical and radiological remission.

RESULTS

Upon clinical examination at 24 weeks, 10 patients had combined remission (clinical and radiographic), 4 patients showed improvements, and 1 patient failed. The results were confirmed in all patients by pelvic MRI. No relevant postoperative complications nor adverse events were reported.

CONCLUSION

These results suggest that the local injection of autologous microfragmented adipose tissue is a safe and promising "rescue therapy" for patients with multiresistant complex fistulizing PCD. This approach might be proposed as routine because it is affordable, is minimally invasive, has no risk of sphincteric damage, and can be carried out in a day-surgery setting.

Evaluation and management of perianal abscess and anal fistula: SICCR position statement

Perianal sepsis is a common condition ranging from acute abscess to chronic anal fistula. In most cases, the source is considered to be a non-specific cryptoglandular infection starting from the intersphincteric space. Surgery is the main treatment and several procedures have been developed, but the risks of recurrence and of impairment of continence still seem to be an unresolved issue. This statement reviews the pertinent literature and provides evidence-based recommendations to improve individualized management of patients.

Bone Tissue Regeneration in the Oral and Maxillofacial Region: A Review on the Application of Stem Cells and New Strategies to Improve Vascularization

Bone tissue engineering techniques are a promising alternative for the use of autologous bone grafts to reconstruct bone defects in the oral and maxillofacial region. However, for successful bone regeneration, adequate vascularization is a prerequisite. This review presents and discusses the application of stem cells and new strategies to improve vascularization, which may lead to feasible clinical applications. Multiple sources of stem cells have been investigated for bone tissue engineering. The stromal vascular fraction (SVF) of human adipose tissue is considered a promising single source for a heterogeneous population of essential cells with, amongst others, osteogenic and angiogenic potential. Enhanced vascularization of tissue-engineered grafts can be achieved by different mechanisms: vascular ingrowth directed from the surrounding host tissue to the implanted graft, vice versa, or concomitantly. Vascular ingrowth into the implanted graft can be enhanced by (i) optimizing the material properties of scaffolds and (ii) their bioactivation by incorporation of growth factors or cell seeding. Vascular ingrowth directed from the implanted graft towards the host tissue can be achieved by incorporating the graft with either (i) preformed microvascular networks or (ii) microvascular fragments (MF). The latter may have stimulating actions on both vascular ingrowth and outgrowth, since they contain angiogenic stem cells like SVF, as well as vascularized matrix fragments. Both adipose tissue-derived SVF and MF are cell sources with clinical feasibility due to their large quantities that can be harvested and applied in a one-step surgical procedure. During the past years, important advancements of stem cell application and vascularization in bone tissue regeneration have been made. The development of engineered in vitro 3D models mimicking the bone defect environment would facilitate new strategies in bone tissue engineering. Successful clinical application requires innovative future investigations enhancing vascularization.

Autologous micro-fragmented adipose tissue for the treatment of diabetic foot minor amputations: a randomized controlled single-center clinical trial (MiFrAADiF)

Background

The diabetic foot ulcer (DFU) is one of the most prevalent complications of diabetes mellitus and often develops severe effects that can lead to amputation. A non-healing “minor” amputation often precedes a major amputation resulting in a negative impact on the function and quality of life of the patients. Stem cell-based therapies have emerged as a promising option to improve healing, and the adipose tissue is an abundant and easy to access source. The injection of autologous micro-fragmented adipose tissue at the amputation stump of a diabetic population undergoing a lower limb minor amputation was evaluated and compared with the standard care.

Methods

In this randomized controlled trial with two arms (parallel assignment) and no masking, 114 patients undergoing a lower limb minor amputation were randomized to standard of care or to micro-fragmented adipose tissue injection prepared using a minimal manipulation technique (Lipogems®) in a closed system. Clinical outcomes were determined monthly up to 6 months. Primary endpoint of the study was the evaluation of the healing rate and time after the minor amputation. Secondary endpoints included the assessment of safety, feasibility, technical success, relapse rate, skin tropism, and intensity of pain.

Results

At 6 months, 80% of the micro-fragmented adipose tissue-treated feet healed and 20% failed as compared with the control group where 46% healed and 54% failed (p = 0.0064). No treatment-related adverse events nor relapses were documented, and technical success was achieved in all cases. The skin tropism was improved in the treatment group, and the pain scale did not differ between the two groups.

Conclusion

The results of this randomized controlled trial suggest that the local injection of autologous micro-fragmented adipose tissue is a safe and valid therapeutic option able to improve healing rate following minor amputations of irreversible DFU. The technique overcomes several stem cell therapy-related criticisms and its potential in wound care should be better evaluated and the therapeutic indications could be expanded.

Trial registration

ClinicalTrials.gov number: NCT03276312. Date of registration: September 8, 2017 (retrospectively registered).

Efficacy of Injection of Freshly Collected Autologous Adipose Tissue Into Perianal Fistulas in Patients With Crohn's Disease

BACKGROUND & AIMS

Perianal fistulas are common in patients with Crohn's disease (CD). Injections of cultured autologous and allogeneic adipose tissue-derived stem cells have been shown to heal CD-associated fistulas. Unfortunately, this treatment is time consuming and expensive. We investigated the effects of injecting freshly collected autologous adipose tissue into perianal fistulas in patients with CD.

METHODS

In a prospective interventional study, freshly collected autologous adipose tissues were injected into complex perianal fistulas of 21 patients with CD, from March 2015 through June 2018. The primary endpoint was complete fistula healing (no symptoms of discharge, no visible external fistula opening in the perineum, and no internal opening detected by rectal digital examination) 6 months after the last injection. We performed pelvic magnetic resonance imaging to confirm fistula resolution in patients with intersphincter and transsphincter fistulas who showed complete healing at clinical examination. Patients without complete fistula healing after 6 weeks and those with later relapse were offered additional injections. No control individuals were included.

RESULTS

Six months after the last adipose tissue injection, 12 patients (57%) had complete fistula healing. Three patients (14%) had ceased fistula secretion, and 1 patient (5%) reported reduced secretion. Among 10 patients with trans-sphincter or inter-sphincter fistulas, magnetic resonance imaging showed complete fistula resolution in 9 patients and a markedly reduced gracile fistula in the remaining patient. Of the 12 patients with complete fistula healing, 9 (43%) required 1 injection, 2 (10%) required 2 injections, and 1 (5%) required 3 injections. The predominant adverse effect was postprocedure proctalgia lasting a few days. Two patients developed small abscesses, 1 had urinary retention, and 1 had minor bleeding during liposuction.

CONCLUSION

In a study of 21 patients with CD and perianal fistulas, we found injection of recently collected autologous adipose tissue to be safe and to result in complete fistula healing in 57% of patients. ClinicalTrials.gov, Number: NCT03803917.

Long-Lasting Anti-Inflammatory Activity of Human Microfragmented Adipose Tissue

Over the last few years, human microfragmented adipose tissue (MFAT), containing significant levels of mesenchymal stromal cells (MSCs) and obtained from fat lipoaspirate (LP) through a minimal manipulation in a closed system device, has been successfully used in aesthetic medicine as well as in orthopedic and general surgery. Interestingly, in orthopedic diseases, this ready-to-use adipose tissue cell derivative seems to have a prolonged time efficacy even upon a single shot injection into osteoarthritic tissues. Here, we investigated the long-term survival and content of MSCs as well the anti-inflammatory activity of LP and its derived MFAT in vitro, with the aim to better understand a possible in vivo mechanism of action. MFAT and LP specimens from 17 human donors were investigated side by side. During a long-term culture in serum-free medium, we found that the total cell number as well the MSC content in MFAT decreased more slowly if compared to those from LP specimens. The analysis of cytokines and growth factors secreted into the conditioned medium (CM) was similar in MFAT and LP during the first week of culture, but the total amount of cytokines secreted by LP decreased much more rapidly than those produced by MFAT during prolonged culture (up to 28 days). Similarly, the addition of MFAT-CM recovered at early (3-7 days) and late stage (14-28 days) of culture strongly inhibited inflammatory function of U937 monocyte cell line, whereas the anti-inflammatory activity of LP-CM was drastically reduced after only 7 days of culture. We conclude that MFAT is an effective preparation with a long-lasting anti-inflammatory activity probably mediated by a long-term survival of their MSC content that releases a combination of cytokines that affect several mechanisms involved in inflammation processes.

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.