Modern Treatments and Stem Cell Therapies for Perianal Crohn's Fistulas

Mesenchymal stem cells transplantation for perianal fistulas: a systematic review and meta-analysis of clinical trials

BACKGROUND

Perianal fistulas, characterised as granulomatous inflammation of fistulas around the anal canal, are associated with significant morbidity resulting in a negative impact on quality of life and a tremendous burden to the healthcare system. Treatment of anal fistulas usually consists of anal surgery; however, results of closure rates are not satisfactory especially with complex perianal fistulas, after which many patients may suffer from anal incontinence. Recently, the administration of mesenchymal stem cells (MSCs) has shown promising efficacy. Herein, we aim to explore whether MSCs are effective for complex perianal fistulas and if they have either short-term, medium-term, long-term or over-long-term efficacy. Additionally, we want to elucidate whether factors such as drug dosage, MSC source, cell type, and disease aetiology influence treatment efficacy. We searched four online databases and analysed data based on information within the clinical trials registry. The outcomes of eligible trials were analysed with Review Manager 5.4.1. Relative risk and related 95% confidence interval were calculated to compare the effect between the MSCs and control groups. In addition, the Cochrane risk of bias tool was applied to evaluate the bias risk of eligible studies. Meta-analyses showed that therapy with MSCs was superior to conventional treatment for complex perianal fistulas in short-, long- and over-long-term follow-up phases. However, there was no statistical difference in treatment efficacy in the medium term between the two methods. Subgroup meta-analyses showed factors including cell type, cell source and cell dosage were superior compared to the control, but there was no significant difference between different experimental groups of those factors. Besides, local MSCs therapy has shown more promising results for fistulas as a result of Crohn's Disease (CD). Although we tend to maintain that MSCs therapy is effective for cryptoglandular fistulas equally, more studies are needed to confirm this conclusion in the future.

SHORT CONCLUSION

MSCs Transplantation could be a new therapeutic method for complex perianal fistulas of both cryptoglandular and CD origin showing high efficacy in the short-term to over-long-term phases, as well as high efficacy in sustained healing. The difference in cell types, cell sources and cell dosages did not influence MSCs' efficacy.

Mesenchymal Stem Cells and PRP Therapy Favorize Leak Closure After Sleeve Gastrectomy in Zucker Rats

INTRODUCTION

Sleeve gastrectomy (SG) is the most performed bariatric surgery but gastric leaks following SG occur in up to 2% of cases. Regenerative medicine is emerging as a promising field offering multiple possibilities in wound healing. We studied the efficiency of locally administered mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) on leak closure following SG in rats.

METHODS

The amount of PRP and MSCs extracted from one rat was analyzed and a model of gastric leak was developed in 10-week-old male Zucker rats. Twenty-four rats underwent SG fashioned with a leak. After 24 h, a second surgery was performed. The control group was treated by peritoneal lavage and drainage only while the experimental group received an additional treatment of locally administered MSCs and PRP at the leak orifice. Analysis of the leak healing process was done by an anatomopathological examination of the stomach 1, 2, 3, and 4 weeks after SG.

RESULTS

The extraction of MSCs and PRP from one rat was necessary for three recipients. Anatomopathological examination suggests that the closure of the leak orifice was faster in the experimental group. Statistical analysis revealed a significantly increased mucosae renewal and fibrosis score at the leak orifice after treatment with MSCs and PRP (p < 0.001).

CONCLUSION

These results suggest that PRP and MSCs may accelerate the closure of leaks following SG in rats and may become a new tool in the treatment of human gastric leaks but more research on this topic is needed to confirm these findings.

Adipose tissue-derived stem cells: a new approach to the treatment of Crohn's disease-associated perianal fistulae

Crohn's disease has an ever-increasing prevalence and incidence, with about 20% of patients developing perianal fistula with significant impact on their quality of life.

Despite the medical and surgical treatments currently used, Crohn's-related fistula treatment continues to pose a challenge due to the low rates of efficacy associated with high recurrence rates.

Recent clinical trials have shown promising results regarding safety and efficacy of local treatment of this condition with the use of adipose tissue-derived mesenchymal stem cells. Besides being pluripotent and poorly immunogenic, they have immunomodulatory and anti-inflammatory properties, which combined, may accelerate healing.

Our main objective is to summarize the clinical trials we found, highlighting the efficacy rates of this therapy and the main limitations we found in the analysis of the results.

We conclude that, in perianal fistulas refractory to conventional therapies, the treatment with adipose tissue-derived mesenchymal cells is safe with promising results that may change the current paradigm of Crohn's related fistula treatment.

Treatment Strategy for Perianal Fistulas in Crohn Disease Patients: The Surgeon's Point of View

Perianal fistula is a frequent complication and one of the subclassifications of Crohn disease (CD). It is the most commonly observed symptomatic condition by colorectal surgeons. Accurately classifying a perianal fistula is the initial step in its management in CD patients. Surgical management is selected based on the type of perianal fistula and the presence of rectal inflammation; it includes fistulotomy, fistulectomy, seton procedure, fistula plug insertion, video-assisted ablation of the fistulous tract, stem cell therapy, and proctectomy with stoma creation. Perianal fistulas are also managed medically, such as antibiotics, immunomodulators, and biologics including anti-tumor necrosis factor-alpha agents. The current standard treatment of choice for perianal fistula in CD patients is the multidisciplinary approach combining surgical and medical management; however, the rate of long-term remission is low and is reported to be 50% at most. Therefore, the optimum management strategy for perianal fistulas associated with CD remains controversial. Currently, the goal of management for CD-related perianal fistulas are controlling symptoms and maintaining long-term anal function without proctectomy, while monitoring progression to anorectal carcinoma. This review evaluates perianal fistula in CD patients and determines the optimal surgical management strategy based on recent evidence.

Substantial Overview on Mesenchymal Stem Cell Biological and Physical Properties as an Opportunity in Translational Medicine

Mesenchymal stem cells (MSC) have piqued worldwide interest for their extensive potential to treat a large array of clinical indications, their unique and controversial immunogenic and immune modulatory properties allowing ample discussions and debates for their possible applications. Emerging data demonstrating that the interaction of biomaterials and physical cues with MSC can guide their differentiation into specific cell lineages also provide new interesting insights for further MSC manipulation in different clinical applications. Moreover, recent discoveries of some regulatory molecules and signaling pathways in MSC niche that may regulate cell fate to distinct lineage herald breakthroughs in regenerative medicine. Although the advancement and success in the MSC field had led to an enormous increase in the amount of ongoing clinical trials, we still lack defined clinical therapeutic protocols. This review will explore the exciting opportunities offered by human and animal MSC, describing relevant biological properties of these cells in the light of the novel emerging evidence mentioned above while addressing the limitations and challenges MSC are still facing.

Anorectal Crohn's Disease

Medical treatment remains the mainstay of perianal disease management for CD; however, aggressive surgical management should be considered for severe or recurrent disease. In all cases of perianal CD, medical and surgical treatments should be used in tandem by a multidisciplinary team. Significant development has been made in the treatment of Crohn's-related fistulas, particularly minimally invasive options with recent clinical trials showing success with mesenchymal stem cell applications. Inevitably, some patients with severe refractory disease may require fecal diversion or proctectomy. When considering reversal of a diverting or end ileostomy, cessation of proctitis is the most important factor.

Advances in Perianal Disease Associated with Crohn's Disease-Evolving Approaches

Perianal diseases, common complications of Crohn's disease, are difficult to diagnose/manage. Patients with perianal Crohn's disease suffer from persistent pain and drainage, recurrent perianal sepsis, impaired quality of life, and financial burden. Conventional medical and surgical therapies carry risk of infection, myelosuppression, incontinence, disease recurrence. Although the phenotype of Crohn's disease has been extensively studied, reported outcomes are inconsistent. Endoanal ultrasonography is also becoming popular because of low cost and ability to acquire images in real time. Emerging management strategies for treatment including laser therapy, local injection of agents, use of hyperbaric oxygen, and stem cell therapy, have demonstrated efficacy.

Early anastomotic complications in colorectal surgery: a systematic review of techniques for endoscopic salvage

BACKGROUND

Anastomotic complications following colorectal surgery are associated with significant morbidity and mortality. For patients in whom systemic sepsis is absent or well controlled, minimal access techniques, such as endoscopic therapies, are being increasingly employed to reduce the morbidity of surgical re-intervention. In this review, we aim to assess the utility of endoscopic management in the acute setting of colorectal anastomotic complications, focusing on anastomotic leak.

METHOD

A literature search was performed for published full text articles using the PubMed, Cochrane and Scopus databases using the search criteria string "colorectal anastomotic ("leak" OR "bleed"), "endoscopy", endoscopic management". Additional papers were detected by scanning the references of relevant papers. Data were extracted from each study by two authors onto a dedicated pro-forma. Given the nature of the data extracted, no meta-analysis was performed.

RESULTS

A total of 89 papers were identified, 16 of which were included in this review; an additional 14 papers were obtained from reference searches. In patients who are not physiologically compromised, there are promising data regarding the salvage rate of stents, over-the-scope endoscopic clips, vacuum therapy and fibrin glue in the early management of colorectal anastomotic leak. There is no consensus regarding the optimal approach, and data to assist the physician in patient selection are lacking. Whilst data on salvage (i.e. healing and avoidance of surgery) are well understood, no data on functional outcomes are reported.

CONCLUSION

Endoscopic therapy in the management of stable patients with colorectal anastomotic leaks appears safe and in selected patients is associated with high rates of technical success. Challenges remain in selecting the most appropriate strategy, patient selection, and understanding the functional and long-term sequelae of this approach. Further evidence from large prospective cohort studies are needed to further evaluate the role of these novel strategies.

The role of topical therapy for perianal fistulizing Crohn's disease: are we forgetting something?

INTRODUCTION

Rectal inflammation is the principal risk factor for the development of perianal fistulizing Crohn's disease. However, no topical therapy direct to rectal healing is discussed in European' guidelines. The aim of this systematic review was to evaluate the role of topical therapy in healing the rectal inflammation in Crohn's disease.

EVIDENCE ACQUISITION

A MEDLINE search of all studies published in English until December 2018 was conducted. Articles were identified using the strings "Crohn's disease and topical therapy" or "perianal Crohn's disease and topical therapy."

EVIDENCE SYNTHESIS

Contradictory results about the efficacy of topical metronidazole were present. No benefit from topical tacrolimus use was demonstrated. Mesalazine suppositories induced and maintained remission of rectal inflammation in 50% of patients with rectal Crohn's disease. Few data were available about the role of local therapy for the fistulous tract in Crohn's disease. Local mesenchymal stem cells therapy could be a promising new approach.

CONCLUSIONS

Due to the disappoint success rate of current strategy in perianal fistulizing Crohn's disease, the role of rectal inflammation as a causative factor and the fair success rate of topical therapy with mesalazine suppositories in the healing of rectal inflammation without relevant side effects, more studies are advisable in this field.

Perianal Fistulas in Patients With Crohn's Disease, Part 2: Surgical, Endoscopic, and Future Therapies

The treatment of perianal fistulas remains a clinical challenge despite the significant advances that have been made in the management of luminal inflammatory bowel disease. In combination with medical therapies, surgical management of perianal fistulas is important for both infection control and definitive repair. Older surgical techniques include the placement of draining and cutting setons and endorectal advancement flaps. Newer surgical techniques that utilize lasers and video-assisted technology are being studied to help patients with chronic, refractory perianal fistulas. In addition to surgical management, less-invasive endoscopic techniques, including endoscopic fistulotomy and endoscopic clipping, are being investigated. Looking forward, allogeneic and autologous adult mesenchymal stem cells are being evaluated to induce fistula healing and improve rates of fistula closure. Here, in the second of a 2-part series on perianal fistulas in patients with Crohn's disease, we discuss the current surgical management of perianal fistulas as well as newer endoscopic techniques and future therapies.

Genetics and immunodysfunction underlying Behçet's disease and immunomodulant treatment approaches

Behçet's disease (BD) is a chronic autoimmune condition primarily prevalent in populations along the Mediterranean Sea. The exact etiology of BD has not been fully explained yet, but the disease occurrence is associated with a genetic factor, human leukocyte antigen (HLA)-B51 antigen. Among the various immunodysfunctions that are found in BD, patients are increased neutrophil motility and superoxide production, as well as elevated production of tumor necrosis factor (TNF)-α and decreased production of interleukin (IL)-10. Elevated levels of inflammatory cytokines like IL-1 and IL-17 in BD have been found associated with aberrant expression of microRNA. Gene polymorphisms in BD patients have been observed in molecules involved in responses to pathogens that can ultimately modulate the host antimicrobial response. Moreover, several single nucleotide polymorphisms (SNPs) have been reported in genes encoding chemokines and adhesion molecules; many of these changes manifest as increases in vascular inflammation and vascular damage. Lastly, genetic and epigenetic changes have been suggested as involved in the pathogenesis of BD. Modifications in DNA methylation have been found in BD patient monocytes and lymphocytes, leading to adverse function of these cells. This review presents a comprehensive compilation of the literature with regard to the immunodysfunction underlying BD, as well as of the genetics, newly described clinical specifications and novel treatment strategies using immunomodulants based on the current understanding of BD.

Treatment of perianal Crohn's disease

Perianal Crohn's is a common manifestation of Crohn's disease. Primary manifestations of perianal disease mirror common anorectal conditions, however treatment is less successful than in those patients without Crohn's related perianal disease. A multimodal approach to therapy including medical and surgical modalities is often necessary. The goal of treatment is to manage symptoms while maintaining continence.