Autologous Platelet-Rich Plasma in the Treatment of Perianal Fistula in Crohn's Disease

Management of Perianal Fistulizing Crohn's Disease

Perianal fistulizing Crohn's disease (CD) represents a severe phenotype of CD that is associated with significant morbidity and reduction in quality of life. Perianal fistulizing CD is caused by a complex interplay of genetic predisposition, immune dysregulation, gut dysbiosis, and various unknown physiological and mechanical factors. A multidisciplinary approach is hence required for optimal management . A detailed anatomical description and classification of perianal fistula, including comprehensive clinical, endoscopic, and radiological diagnostic workup, is an important prerequisite to treatment. For simple perianal fistulas, use of antibiotics and immunomodulators, with or without fistulotomy, are appropriate measures. The medical management of complex perianal fistula, on the other hand, requires adequate control of infection before initiation of therapy with immunomodulators. In active complex perianal fistula, anti-tumor necrosis factors remain the most accepted therapy, with concomitant use of antibiotics or immunomodulators enhancing the efficacy. For patients refractory to anti-tumor necrosis factors, treatment with anti-integrins, anti-interleukins, and small molecules is being evaluated. Mesenchymal stem cells, hyperbaric oxygen therapy, and exclusive enteral nutrition have also been investigated as adjunct therapies. Despite the expansion of the medical armamentarium, a large proportion of the patients require surgical interventions. In this review, we provide an up-to-date overview of the pathophysiology, clinical presentation, diagnosis, and medical management of perianal fistulizing CD. A brief overview of the surgical management of perianal fistulizing CD is also provided.

Platelet-rich plasma in the treatment of anal fistula: a systematic review and meta-analysis

OBJECTIVE

To analyse the safety and effectiveness of platelet-rich plasma (PRP) in anal fistula patients.

METHODS

Online databases including PubMed, Embase, Cochrane Library, and Web of Science were searched from inception to December 5, 2022, for eligible studies about evaluating the efficacy of platelet-rich plasma (PRP) in treating anal fistula. Literature search, screening, data extraction, and quality assessment were carried out by two independent investigators. The overall cure rate, the complete cure rate, the recurrence rate, and the adverse event rate with their 95% confidence intervals (95% CI) were the primary calculation indexes. Subgroup analyses were conducted primarily according to whether PRP was combined with other treatments. Softwares of MedCalc 18.2 and Review Manager 5.3 were used for meta-analysis.

RESULTS

A total of 14 studies with 514 patients were included in the meta-analysis. The overall cure rate of 14 studies was 72.11% (95% CI 0.64-0.79). The cure rate of PRP alone was 62.39% (95% CI 0.55-0.69). The combined cure rate of PRP with other treatments was 83.12% (95% CI 0.77-0.88). The cure rate of interventions involving PRP were superior to the cure rate of surgery methods without using PRP significantly in the 4 randomized controlled studies (RR = 1.30, 95% CI 1.10-1.54, p = 0.002). The complete cure rate of the 8 studies was 66.37% (95% CI 0.52-0.79). The recurrence rate of the 12 studies was 14.84% (95% CI 0.08-0.24). The adverse event rate of the 12 studies was 6.31% (95% CI 0.02-0.12).

CONCLUSION

PRP showed favorable safety and effectiveness in the treatment of anal fistula, especially combined with other treatment procedures.

Autologous Bioactive Compound Concentrated Growth Factor Ameliorates Fistula Healing of Anal Fistula in a Pig Model and Promotes Proliferation and Migration of Human Skin Fibroblasts via Regulating the MEK/ERK Pathway

Recent evidence suggested that autologous concentrated growth factor (CGF), a new bioactive compound from autologous blood is used widely as an ingenious biomaterial in tissue regeneration with anti-inflammatory properties. This study investigated whether CGF could be involved in the treatment of fistula healing in the anal fistula. For this purpose, the porcine anal fistula model was conducted using the rubber band ligation method and collected pig autogenic CGF to treat the fistulas. CGF treatment promoted fistula healing, which was reflected in the downregulation of inflammatory factors, upregulation of growth factors, and promoted epithelial-mesenchymal transition with increased collagen synthesis. Besides, 16S rRNA gene sequencing analysis of fistula tissues between the control and CGF groups showed that the microbial populations exhibiting significant differences were VadinCA02, Blastomonas, Deinococcus, Devosia, Sphingomonas, Rubrobacteria, and GW_34. CGF of volunteers were collected to process small interfering RNA- (siRNA-) ERK or siRNA-negative control transfected human skin fibroblasts (HSF). The results showed that CGF also promoted the proliferation and extracellular matrix-related functions in HSF, as well as activated the MEK/ERK pathway in vitro and in vivo. Finally, knockdown ERK reversed the effects of CGF in promoting wound healing in HSF. Collectively, our results suggest that the CGF as the bioactive compound from autologous blood exhibited great potential for repairing fistulas as well as promoting the proliferation and migration of human skin fibroblasts by triggering MEK/ERK signaling. These findings provided a fresh perspective for understanding the role of CGF in the management of fistulas.

Treatments for the amelioration of persistent factors in complex anal fistula

Anal fistulae are abnormal hollow connections between the wall of the anal canal and the perianal skin around the anus that have remained a burden on the medical sector for centuries. The complexity of this disease is attributed to a number of factors such as the degree of associated sphincter muscle, concomitant illnesses, existence of multiple fistulous tracts and the number of previous interventions. Persistence of a complex anal fistula can cause a decline in patient's physical quality of life as well as impact on the psychological status of patients who often suffer from anxiety and depression. Surgical intervention remains the gold standard for treatment, however; the risk of incontinence and high recurrence potential has led to interest into developing alternative treatment approaches such as the use of biologics, bioactives and biomaterials. One potential reason for these varied outcomes could be the multifactorial interplay between genetic, immune-related, environmental, and microbial persistence factors on tissue regeneration. Recent observations have proposed that adverse inflammatory mediators may contribute more than microbial factors. The moderate to high success rates of biotechnological advances (mesenchymal stem cells and biomaterial scaffolds) show promise as therapies for the amelioration of adverse persistent factors while facilitating a means to closing the fistula tract. The purpose of this review is to outline recent advances in biologics and combination therapies to treat persistent factors associated with complex anal fistula.

Application of platelet-rich plasma in rectovaginal fistulas in the patients with ulcerative colitis

BACKGROUND

There is a need for other than surgical methods of therapy for small and low rectovaginal fistulas (RVF) in the course of inflammatory bowel diseases (IBD), such as application of fibrin sealants, stem cells, biological therapy, or platelet-rich plasma. The aim of this study was to evaluate the results of the treatment after local application of PRP in aforementioned fistulas, exclusively in the patients with ulcerative colitis (UC).

PATIENTS AND METHODS

Medical records of 13 patients with small and low-lying, active RVF in the course of UC, and after restorative proctocolectomy for UC were evaluated. Curettage of fistulous tracts was performed with the following application of PRP in all patients.

RESULTS

Complete closure of RVF was achieved after the first injection in 4 patients, 3 women healed their fistulas following the second application, and two of them closed RVF after 3 injections. To sum up, the complete closure of RVF was achieved in 9 (69%) patients. Fistulas remained closed from 6 to 12 months.

CONCLUSIONS

The application of PRP in small, low, and recurrent IBD anal fistulas is effective, simple, and safe with an acceptable rate of healing. This therapy might also precede any further, surgical methods of treatment.

Ligation of intersphincteric fistula tract (LIFT) with or without injection of platelet-rich plasma (PRP) in management of high trans-sphincteric fistula-in-ano: Short-term outcomes of a prospective, randomized trial

BACKGROUND

Success rate after ligation of the inter-sphincteric fistula tract ranges from 40% to 75%. Platelet-rich plasma is hypothesized to improve healing by slowly releasing growth factors. The objective of the study was to compare the efficacy and outcome of ligation of the inter-sphincteric fistula tract plus platelet-rich plasma local injection versus ligation of the inter-sphincteric fistula tract alone in the management of high trans-sphincteric anal fistula in regards to postoperative pain, time for healing, morbidity, fistula closure rate, recurrence, and quality of life.

METHODS

This was a prospective randomized trial. Patients with trans-sphincteric anal fistulas involving >50% of anal sphincters were included. Patients were randomly assigned to either ligation of the inter-sphincteric fistula tract plus platelet-rich plasma or ligation of the inter-sphincteric fistula tract (49 in each group). The primary endpoints were successful complete fistula closure and duration needed for healing. Secondary endpoints were morbidity, recurrence after 1 year of follow-up, postoperative pain, and quality of life.

RESULTS

Complete primary healing was recorded in 42 patients in the ligation of the inter-sphincteric fistula tract plus platelet-rich plasma group and 32 patients in the ligation of the inter-sphincteric fistula tract group, and the difference was statistically significant (P = .03). The mean time to complete healing after ligation of the inter-sphincteric fistula tract plus platelet-rich plasma was significantly shorter than after ligation of the inter-sphincteric fistula tract alone (15.7 ± 4 days vs 21.6 ± 5.4 days; P = .03). One year after complete healing of anal fistula, recurrence was recorded in 4/42 patients in the ligation of the inter-sphincteric fistula tract plus platelet-rich plasma group and 3/32 patients in the ligation of the inter-sphincteric fistula tract group with no statistically significant difference (P = .99). Patients in the ligation of the inter-sphincteric fistula tract plus platelet-rich plasma group had significantly lower pain scores after both 1 and 7 days. Quality of life and level of happiness were significantly better 1 month after ligation of the inter-sphincteric fistula tract plus platelet-rich plasma.

CONCLUSION

Ligation of the inter-sphincteric fistula tract plus platelet-rich plasma for the treatment of high trans-sphincteric fistula-in-ano is a safe modality with significantly higher successful healing rate, shorter healing time, and less postoperative pain compared with ligation of the inter-sphincteric fistula tract alone. Ligation of the inter-sphincteric fistula tract plus platelet-rich plasma does not improve the rate of recurrence; however, it results in significantly higher short-term quality of life.