Autologous Platelet-Rich Stroma in Complex Perianal Fistulas

Additional Intraoperative Autologous-Derived Platelet-Rich Stroma to Transanal Flap Repair for the Treatment of Cryptoglandular Transsphincteric Fistulas in a Tertiary Referral Center: Long-Term Outcomes of a Prospective Pilot Study

Transanal advancement flap repair (TAFR) fails in approximately 30-40% of patients with a cryptoglandular transsphincteric fistula. An additional intraoperative injection of autologous platelet-rich stroma (PRS) with TAFR proved to be safe, feasible, and effective in the short term for the treatment of cryptoglandular transsphincteric fistula in a tertiary referral center. In this study, we assessed the long-term outcomes in patients with a cryptoglandular transsphincteric fistula who were treated with an additional intraoperative autologous PRS injection with TAFR (n = 43). The majority of the patients (88%) had a complex transsphincteric fistula (high transsphincteric and/or multiple side tracts) and underwent (one or more) fistula procedure(s) aimed at fistula repair (56%) before study inclusion. At a median follow-up time of 4.2 years [IQR 3.5-5.1], long-term primary clinical closure (i.e., clinical closure of the treated external fistula opening(s) after TAFR with additional PRS injection without the need for any re-interventions during long-term follow-up) was observed in 77% of the patients. Subsequently, 94% of these patients also reached radiological healing (i.e., fibrotic fistula tract on MRI). Recurrence after clinical closure or radiological healing was observed in 9% and 5%. Unplanned re-interventions were performed in 12% of the patients for recurrent or residual fistulizing disease. In this uncontrolled pilot study, additional autologous PRS injection with TAFR showed promising outcomes, as long-term primary clinical closure and, subsequently, radiological healing was reached in the vast majority of tertiary referral patients with a (complex) cryptoglandular transsphincteric fistula at long-term follow-up. In addition, recurrence rates were low. Future randomized research is warranted to study the effects of PRS.

Platelet-Rich Plasma: Characteristics and Current Review of its Use in Surgery

Platelet-rich plasma (PRP) is presently employed across various medical disciplines, including surgical specialties. It is primarily used in the healing of chronic wounds, burn medicine, tissue regeneration support, and scar correction as well as in other surgical and orthopedic indications. Wounds, in general, possess a pro-inflammatory biochemical environment characterized by high protease activity that diminishes the effective concentration of growth factors. In contrast, PRP serves as a source of growth factors and exhibits mitogenic, angiogenic, and chemotactic properties. PRP is a biological product defined as a portion of the autologous blood's plasma fraction with a higher than physiological platelet concentration. PRP is obtained through the centrifugation of blood samples collected from patients. The insights into the biology, mechanism of action, and classification of PRP presented in this review can assist medical professionals in orienting themselves and comprehending the possibilities of the clinical application of this therapy, which remains a subject of investigation and validation. This review summarizes up-to-date information regarding the use of PRP, primarily in burn and reconstructive surgery, plastic surgery, traumatology, and general surgery.

Stromal vascular fraction with platelet-rich plasma injection during surgery is feasible and safe in treatment-refractory perianal fistulising Crohn's disease: A pilot study

BACKGROUND

An unmet need remains for improved management in perianal fistulising Crohn's disease (pCD). Recently, local administration of adipose-derived cells has shown promising results.

AIMS

To assess the safety and feasibility of injection of stromal vascular fraction (SVF) with platelet-rich plasma (PRP) in patients with pCD.

METHODS

Patients ≥ 18 years with pCD were included and underwent fistula curettage, SVF with PRP injection, and closure of the internal opening. The primary endpoint was safety at 12 months. The secondary outcomes were complete radiological healing at 3 months (absence of fluid-containing tracts on MRI) and partial and complete clinical response at 3 and 12 months (closure of ≥1, respectively, all treated external opening(s)).

RESULTS

Twenty-five patients were included (35 [IQR 25-40] years; 14 [56%] female); median CD duration 4 [IQR 2-8] years. Twenty-four (95%) patients had previously undergone fistula surgery. No adverse events were encountered at lipoharvesting sites. Two (8%) patients were readmitted to hospital and six (24%) underwent unplanned re-interventions. Post-operative MRI (n = 24) showed complete radiological healing in nine (37.5%) patients. Partial clinical response was present in 48% (12/25) at 3 months and in 68% (17/25) at 12 months, and complete clinical closure in five (20%) patients at 3 months and in 10 (40%) patients at 12 months.

CONCLUSION

Injection with autologous SVF with PRP is feasible and safe in patients with treatment-refractory pCD. Early complete radiological healing was observed in more than one-third of patients, and clinical response in two-thirds of patients at 12 months.

Platelet-Rich stroma from Crohn's disease patients for treatment of perianal fistula shows a higher myeloid cell profile compared to non-IBD controls

BACKGROUND

New cell-based therapies are under investigation to improve perianal fistulizing Crohn's disease (pCD) healing. Autologous stromal vascular fraction combined with platelet-rich plasma (referred to as platelet-rich stroma [PRS]) is a new adipose-derived stromal therapy. The effect of Crohn's disease (CD) on adipose tissue, and adipose-derived therapies, is largely unknown. We characterized the cellular composition of subcutaneous lipoaspirate and PRS of pCD patients and non-Inflammatory Bowel Disease (IBD) controls.

METHODS

Consecutive pCD patients (≥18 years) and non-IBD controls, who underwent liposuction for the purpose of autologous PRS therapy, were included (October 2020 and March 2021). Mechanically fractionated lipoaspirate and the combined PRS product were analyzed for cell surface marker expression using fluorescence-activated cell sorting analysis.

RESULTS

Twenty-three patients (37.8 [IQR 30.7-45.0] years; 9 [39.1 %] male; 11CD patients) were included. Similar total number of cells were found in CD and non-IBD lipoaspirate (CD 8.23 ± 1.62*10⁵ cells/mL versus non-IBD 12.20 ± 3.39*10⁵). Presence of stromal cells, endothelial like cells, immune cells, T-cells, myeloid cells and M2/M1 macrophage ratio were similar in CD and non-IBD lipoaspirate. In PRS samples, more cells/mL were seen in CD patients (P = 0.030). Myeloid cells were more abundant in CD PRS samples (P = 0.007), and appeared to have a higher regulatory M2/M1 ratio. Interdonor variation was observed between lipoaspirate and PRS samples.

CONCLUSIONS

The composition of CD and non-IBD lipoaspirate were found to be similar and interdonor variation was observed. However, PRS from CD patients showed more myeloid cells with a regulatory phenotype. Crohn's disease does not appear to alter the immunological composition of adipose-derived products.

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/