Pilot study: fibrin sealant in anal fistula model

A Novel Patient-like Swine Model of Perianal Crohn's Disease

BACKGROUND

Perianal Crohn's disease is associated with poor outcomes and high medical costs. It is notoriously difficult to treat despite therapeutic advancements for luminal disease. A large animal model that mimics human perianal disease is needed to test innovative therapies.

OBJECTIVE

This study aimed to create a swine model that replicates the inflammatory component and therapeutic challenges found in patients with perianal Crohn's disease.

DESIGN

This was an animal preclinical study.

SETTINGS

The experiments were performed at the animal laboratory at the Johns Hopkins University.

PATIENTS

Four sus scrufus female pigs were included in the study.

INTERVENTIONS

Four female pigs underwent creation of 3 surgical perianal fistulas each, 1 rectovaginal and 2 perianal. Size 24 French setons were placed to maintain patency of the fistula tracts for 4 weeks. After removal of the setons, trinitrobenzene sulfonic acid was administered into the fistula tract to create and maintain local inflammation mimicking perianal Crohn's disease.

MAIN OUTCOMES MEASURES

An MRI was obtained to assess the fistulas and the pigs were euthanized to review histopathology.

RESULTS

Three inflammatory chronic fistula tracts were successfully created in each pig as confirmed by MRI and examination under anesthesia. This is the first report of maintaining patent fistulas in swine 2 weeks after removal of setons. For the first time, we reported that 2 pigs developed branching fistulas and small abscesses reminiscent of human perianal Crohn's disease. The corresponding histopathologic examination found significant chronic active inflammation on standard hematoxylin and eosin staining.

LIMITATIONS

The fistulas were surgically induced and did not occur naturally.

CONCLUSIONS

A chronic perianal fistula model in pigs that strongly resembles human perianal Crohn's disease was successfully created. This model can be used to test novel therapeutics and techniques to pave the path for human trials. See Video Abstract at http://links.lww.com/DCR/B969 .

UN NUEVO MODELO PORCINO SIMILAR A UN PACIENTE DE LA ENFERMEDAD DE CROHN PERIANAL ANTECEDENTES

La enfermedad de Crohn perianal se asocia con malos resultados y altos costos médicos. Es notoriamente difícil de tratar a pesar de los avances terapéuticos para la enfermedad luminal. Se precisa de un modelo animal grande que imite la enfermedad perianal humana para probar terapias innovadoras.OBJETIVO:Nuestro objetivo de este estudio fue crear un modelo porcino que replique el componente inflamatorio y los desafíos terapéuticos que se encuentran en los pacientes con enfermedad de Crohn perianal.DISEÑO:Este fue un estudio preclínico en animales.AJUSTES:Los experimentos se realizaron en el laboratorio de animales de la Universidad Johns Hopkins.PACIENTES:Se incluyeron en el estudio cuatro cerdas sus scrofa.INTERVENCIONES:Cuatro cerdas fueron sometidas a la creación de 3 fístulas perianales quirúrgicas cada una: 1 recto vaginal y 2 perianales. Se colocaron sedales de 24 French para mantener la permeabilidad de los trayectos fistulosos durante 4 semanas. Tras el retiro de los sedales, se administró ácido trinitrobenceno sulfónico en el trayecto de la fístula para crear y mantener la inflamación local simulando la enfermedad de Crohn perianal.PRINCIPALES MEDIDAS DE RESULTADOS:Se obtuvo una resonancia magnética para evaluar las fístulas y los cerdos fueron sacrificados para revisar la histopatología.RESULTADOS:Se crearon de manera exitosa tres trayectos fistulosos inflamatorios crónicos en cada cerdo, confirmados por imágenes de resonancia magnética y examen bajo anestesia. Este es el primer informe de preservación de fístulas permeables en cerdos 2 semanas tras el retiro de los setones. Por primera vez, informamos que dos cerdos desarrollaron fístulas ramificadas y pequeños abscesos que recuerdan a la enfermedad de Crohn perianal humana. El examen histopatológico correspondiente encontró una significativa inflamación crónica activa en la tinción estándar de hematoxilina y eosina.LIMITACIONES:Las fístulas se indujeron quirúrgicamente y no se produjeron de forma natural.CONCLUSIONES:Se logro recrear con éxito un modelo de fístula perianal crónica en cerdos que se asemeja mucho a la enfermedad de Crohn perianal humana. Este modelo se puede utilizar para probar nuevas terapias y técnicas para allanar el camino para los ensayos en humanos. Consulte Video Resumen en http://links.lww.com/DCR/B969 . (Traducción-Dr Osvaldo Gauto).

Establishment of a novel experimental model of infected anal fistula in rat

Refractory Crohn's-like enterocutaneous fistula indicates the aggressive manifestation and lead to poor prognosis of patients. The development of multidisciplinary strategies for fistula administration largely subjects to the deficiency of animal model for disease remodeling and the underlying pathogenic mechanism. For the purpose, infected anal fistula model was conducted by BLV single-core electrolytic aluminum combined with dextran sodium sulfate. Notably, the inflammatory granulation tissue and inflammatory cell infiltration in the perianal tissue were arised on day 7 of the model by utilizing the Hematoxylin–eosin staining. With the aid of magnetic resonance imaging and signals of high-brightness. We intuitively observed the thickening and edema appeared in the fistula wall, which collectively suggested the formation of a fistula in the perianal area of the rat. Distinguish from the current models of anal fistula modeling including the body surface of fistula, backside of fistula and drainage wire of fistula, our model revealed multifaceted advantages such as quicker generation, higher modeling rate, preferable stability, better consistency, cost-effective, and in particular, more convenient to mimic clinical manifestations of anal fistula.

3D-Printed Surgical Steel Curettes for the Treatment of Perianal Fistula

Need. The diversity of approaches proposed for the treatment of complex perianal fistulas reflects the fact that no method has yet been shown to be fully satisfactory. We believe the successful treatment of this condition is directly proportional to the amount of fibrous tissue that can be removed. Technical solution. We use a kit of small curettes, of different thicknesses and sizes, incorporating spicules that enable the physician to remove fibrous tissue from the fistula tract. The small size and varying thicknesses of the curettes enable them to mould to the curves of the fistula tract and to remove tissue by deroofing from the shallowest to the deepest layers, thus excising the entire fibrous tract. Our hospital has recently incorporated into clinical practice a new model of 3D-printed surgical steel curette, flanked by 2 lateral rings through which the suture is threaded. The central part of the curette contains radially graduated discs, the tips of which perform the debriding action, removing the fibrous tissue from the tract. Proof of concept. By using these curettes in conjunction with our standard technique (plugging the tract with platelet-rich fibrin), we have improved the success rate from 67% to 88%. Next steps. We have contacted several companies with a view to marketing this product. Conclusion. The results obtained are significantly better than those offered by the techniques in current use for the treatment of complex fistulas, without prejudice to outcomes such as anal continence and morbidity and mortality.

Can Perianal Fistula Be Treated Non-surgically with Platelet-Rich Fibrin Sealant?

INTRODUCTION

In the last 20 years, various procedures have been suggested for the treatment of anal fistula whilst minimising anal sphincter injury and preserving optimal function. Since 2011, patients at our hospital have been treated for anal fistula by means of platelet-rich fibrin plugs. To do so, three different application techniques have been used, the most recent of which is a non-surgical approach. In this paper, we compare and contrast the results obtained by each of these three techniques.

MATERIAL AND METHOD

This study compares three procedures in which the anal fistula was sealed using platelet-rich fibrin: for the patients in group A, the plug was surgically inserted, under anaesthesia, and traditional methods were used to curette the fistula tract and close the internal orifice; for those in group B, the plug was surgically inserted, under anaesthesia, after curettage of the fistula tract using a graduated set of cylindrical curettes, and the internal orifice was closed as before; and for those in group C, the plug was inserted during outpatient consultation, without anaesthesia, without curettage and without closure of the internal orifice.

RESULTS

The patients in the three groups were homogeneous in terms of sex, age, ASA classification, location of the fistula and previous insertion of the seton. There were no significant differences in morbidity or postoperative continence. However, there was a statistically significant difference in the outcomes achieved, in favour of group B, while groups A and C obtained similar results.

CONCLUSIONS

Outpatient treatment of perianal fistula is totally innocuous. It is a very low cost procedure and the results obtained are highly acceptable (similar to those of the surgical insertion of a plug, with traditional curettage). Therefore, we believe this approach should be considered a valid initial treatment for perianal fistula, reserving surgical treatment (curettage and sealing using a cylindrical-curette kit) for cases in which this initial method is unsuccessful. This would avoid many complications and achieve considerable financial savings for the health system.

Percutaneous management of enterocutaneous fistulae and abscess-fistula complexes

Abscess-fistula complexes and enterocutaneous fistulae are due to postoperative, spontaneous, and inflammatory etiologies. Conservative, percutaneous, endoscopic, and surgical treatment options are available options. Interventional radiologists have an array of different treatment strategies, often starting with percutaneous drainage of associated intra-abdominal abscesses. This review article details different percutaneous management strategies, focusing on percutaneous catheter strategies for abscess-fistula complexes along with tract closures strategies for enterocutaneous fistulae.

Platelet-rich fibrin sealant as a treatment for complex perianal fistulas: a multicentre study

INTRODUCTION

The incidence of perianal fistulas is high, and this condition has a profoundly negative impact on patients' quality of life. The problem is greater when the fistula tract is high because treatment is necessarily complex (limited surgery may lead to recurrence, while aggressive surgery is associated with higher rates of faecal incontinence). To achieve a balance between these two options, we suggest that complex fistulas should be treated by sealing the tract with platelet-rich fibrin. Our objective is to evaluate the medium- to long-term results obtained from the treatment of complex perianal fistulas by sealing with platelet-rich fibrin.

MATERIAL AND METHODS

Prospective longitudinal multicentre study involves three colorectal surgeons working at three hospitals. The study period was October 2010 to June 2013, during which a total of 60 patients were treated for complex fistulas. In all cases, the intervention consisted of curetting the fistula tract, sealing it with platelet-rich fibrin and closing the internal orifice. We evaluated the clinical outcomes (clinical examination and pelvic magnetic resonance (MRI)) and the quality of life results, both general (SF-36) and gastrointestinal (GIQLI questionnaire) in periodic reviews during consultation.

RESULT

The median follow-up period was 24 months (11-43 months), during which in 40 patients (66.66 %) the fistulas remained closed, with a zero rate of faecal incontinence. The results of the quality of life questionnaires are comparable (indeed, they are better in some items for the cured patients) to those of the reference population.

CONCLUSION

In our opinion, this procedure is safe and its results are promising in terms of clinical outcome and medium- to long-term quality of life.

Interventional radiologic management and treatment of enterocutaneous fistulae

Enterocutaneous fistulae (ECFs) are abnormal sinus tract communications between the alimentary system and skin surface that can cause significant management problems and cost to the health care system. Interventional radiology can play an important role in diagnosis and treatment when conventional measures fail and additional surgery is difficult or poses a high risk. The management of patients with fistulae requires operator ingenuity and dedication, a multidisciplinary team approach, and an understanding of the pathophysiology. This article reviews the major issues in ECF management and the role of interventional radiology.

Fibrin glue with gentamicin as an alternative to conventional surgery in experimental treatment of duodenal fistula in rats

Duodenal fistula is a significant ongoing surgical problem. Minimal invasive treatment might be an alternative to conventional open surgery. This study aimed to investigate whether addition of gentamicin to fibrin adhesive can augment current surgical methods. Having established a fistula, the defect was closed using the following: simple suturing, suturing covered with fibrin sealant only, or suturing with fibrin sealant mixed with gentamicin. Bursting pressure and macroscopic and microscopic examination were evaluated on the second and sixth day after surgery. The study demonstrated there was no significant difference in overall outcome between the 3 groups. However, on macroscopic examination, the mixture of antibiotic and fibrin adhesive decreased formation of adhesions and abscesses. Microscopically, there was decreased inflammation, improved granulation, and earlier onset of fibrin filament deposition, possibly leading to enhanced wound healing. The addition of gentamicin to fibrin sealant can be a useful adjunct to standard surgical closure in duodenal fistula management.

Staged Mucosal Advancement Flap versus Staged Fibrin Sealant in the Treatment of Complex Perianal Fistulas

Background. In this prospective randomised study, the staged mucosal advancement flap is compared with staged fibrin sealant application in the treatment of perianal fistulas. Methods. All patients with high complex cryptoglandular fistulas were randomised to closure of the internal opening by a mucosal advancement flap (MF) or injection with fibrin sealant (FS) after treatment with setons. Recurrence rate and incontinence disorders were explored. Results. The MF group (5 females and 10 males) with a median age of 51 years and a median followup of 52 months. The FS group (4 females and 11 males) with a median age of 45 years and a median followup of 49 months. Three (20%) patients of the MF group had a recurrent fistula compared to 9 (60%) of the FS group (P = 0.03). No new continence disorders developed. Conclusion. Staged FS injection has a much lower success rate compared to MF.

Management of idiopathic anal fistula using cross-linked collagen: a prospective phase 1 study

AIM

Fibrin glue and porcine intestinal submucosa are used in novel sphincter-preserving techniques to heal anal fistulae. However, their success is highly variable and decreases with the length of follow up. The aim of this study was to assess the safety, feasibility and potential efficacy of another novel agent, cross-linked collagen, in two different physical formats, to heal anal fistulae.

METHOD

Prospectively recruited patients underwent symptom, continence and anal physiology assessments and magnetic resonance imaging. Patients with secondary tracts or acute sepsis were excluded. At operation, participants were randomized to receiving a solid collagen implant or collagen fibres suspended in fibrin glue. Follow up included repeat symptom, continence and physiological assessments at 3 months, and regular clinical review thereafter.

RESULTS

Twenty-nine of 43 entrants were eligible for inclusion. Thirteen patients received the collagen implant, and 16 collagen-fibrin glue. Three months postoperation, no patient experienced acute sepsis or continence disturbance, and sphincter function and integrity were unchanged. At 29 months, 12 of 15 (one lost to follow up) patients treated with collagen-fibrin glue were healed, compared with seven of 13 who received the implant.

CONCLUSION

In the short-to-medium term, both techniques are safe and equally effective. The results justify continued research into the use of biomaterials to heal anal fistulae.

Magnetic resonance imaging in the management of anal fistula and anorectal sepsis

Complex perianal disease may be extremely debilitating for the patient with significant impingement on quality of life. The accurate identification of anatomical areas of involvement and subsequent appropriate management is crucial to achieving a successful outcome when treating anorectal sepsis and anal fistulae. Magnetic resonance imaging (MRI) has become a powerful tool in the evaluation of anal anatomy. In patients with complex disease MRI is an important adjunct in delineating disease location and extent, its relationship to sphincter muscles, and in planning management. MRI also plays an important role in evaluating the response to medical and surgical therapies.

Fibrin glue for the treatment of fistulae in ano--a method worth sticking to?

OBJECTIVE

The current evidence for fibrin glue as a treatment for anal fistulae is mixed. This study reviews the experience of fibrin glue as a treatment for anal fistulae in a single tertiary referral centre and attempts to identify factors related to failure of therapy and the length of follow-up required.

METHOD

Patients with fistulae in ano that were treated with fibrin glue between February 2004 and August 2008 were analysed. All procedures were performed by two colorectal consultants based at the Queens Medical Centre, Nottingham. All patients were followed-up to assess the outcome of this treatment.

RESULTS

Forty patients (21 male, 19 female) with a mean age of 46.5 years were studied. The mean duration of symptoms prior to presentation was 39 months (range 4-240 months). Presenting symptoms included perianal discharge (72.5%), perianal abscess (57.5%), pain (12.5%), PR bleeding (7.5%), itching (5%) and urgency (2.5%). Patients had a minimum of two follow-up appointments and the median follow-up period was 5.2 months (range 1-16 months). Following MRI and operative assessment, 28 (70%) of the 40 fistulae were considered complex (high trans-sphincteric, extra-sphincteric, pouch-vaginal). Patients who had inflammatory bowel disease were classified as simple tracts but all failed to heal (three patients). Twenty of the complex fistulae failed to heal. Three patients who had repeat application of glue for their complex fistulae failed to heal on follow-up. Of the remaining 12 patients who had simple fistulae in ano, five (41.7%) healed completely. There were no complications such as abscess, related to treatment. All patients who were asymptomatic at 3 months did not develop any further recurrence.

CONCLUSION

Fibrin glue is a simple treatment strategy, preserves sphincter function with minimal adverse side effects. It should therefore be considered as possible first line treatment in simple fistulae but it is less likely to be successful in complex or those fistulae associated with inflammatory bowel disease. Repeat gluing is unlikely to be successful. Fistulae that have failed to heal by 3 months will need further treatment.

Histologic analysis of acellular dermal matrix in the treatment of anal fistula in an animal model

BACKGROUND

Human acellular dermal matrix (ADM) has been used successfully for the treatment of severe burns, ureter support, and abdominal wall reconstruction. This study was designed to evaluate the mechanism of ADM in the closure of anal fistula in an experimental porcine model.

STUDY DESIGN

The fistula-in-ano model was created in the porcine model and treated with ADM in 14 animals. Fistula specimens were obtained at hours 12 and 24 and on days 3, 7, 14, 28, 60. Hematoxylin and eosin staining, Masson trichrome staining, and immunohistochemical staining for alpha smooth muscle actin and matrix metalloproteinase 9 were performed.

RESULTS

The cell density increased from hour 12 to day 7 and decreased from day 7 to day 28 (p < 0.001). Mature vessels stained with alpha smooth muscle actin were identified at day 7. Alpha smooth muscle actin-positive myofibroblasts were found in clusters at the edge of the ADM at day 7. The density of vessels (p < 0.001) and myofibroblasts (p < 0.001) increased from day 7 to day 14. The density of matrix metalloproteinase 9 increased from hour 12 to day 7 and decreased from day 14 to day 60 (p < 0.001). Partially organized bundles of muscle were found by day 60.

CONCLUSIONS

We suggest that ADM is a reasonable new option for closure of anal fistulas. Anal fistulas begin to heal as early as 12 hours, and day 7 may be an important time point to judge whether the fistula healed preliminarily or not. The ability of ADM to become vascularized and remodeled by autologous cells may be advantageous for anal fistula healing.

An experimentally successful new sphincter-conserving treatment for anal fistula

PURPOSE

A new sphincter-conserving treatment was evaluated in a porcine model.

METHODS

A total of 36 fistulas were created by procedures that have been published previously. At fistula induction a skin biopsy was taken from which to culture fibroblasts. Four weeks after induction, when fistulas were well established, the fistula tracks were cored out. Collagen paste modified from Permacol injection (Covidien, Mansfield, MA) was then used as a solitary infill material in 11 tracks, cultured autologous fibroblasts being added to this in a further 18 tracks. The track was cored out in seven controls, but these tracks were not treated with infill material. All of the internal and external openings were closed. Anorectal excision was then carried out under terminal anesthesia at 2 to 12 weeks. Histologic examination of individual tracks was performed by an experienced pathologist.

RESULTS

In this quadruped all of the infilled tracks healed, autologous fibroblasts having the best tissue integration, but only two of seven control tracks healed.

CONCLUSIONS

Removal of the fistula track followed by injection of collagen healed all of the cases. The addition of autologous fibroblasts improved the histologic appearance of the tracks. A pilot study in human fistula patients is in progress.

A anorectal fistula treatment with acellular extracellular matrix: A new technique

AIM: To investigate a new technique of the anorectal fistula treatment with acellular extracellular matrix (AEM).

METHODS: Thirty patients with anorectal fistula were treated with AEM. All fistula tracts and primary openings were identified using conventional fistula probe. All tracts were curetted with curet and irrigated with hydrogen peroxide and metronidazole. The AEM was pulled into the fistula tract from secondary to primary opening. The material was secured at the level of the primary opening. The excess AEM was trimmed at skin level at the secondary opening.

RESULTS: All of the 30 patients had successful closure of their fistula after a 7-14 d follow-up. The healing rate of anal fistula in treatment group was 100%. The ache time, healing time and anal deformation of treatment group were obviously superior to traditional surgical methods.

CONCLUSION: Using AEM anal fistula plug in treatment that causes the anorectal fistula is safe and successful in 100% of patients. It can reduce pain, shorten disease course and protect anal function.

Evaluation of the use of BioGlue in the treatment of high anal fistulas: preliminary results of a pilot study

PURPOSE

Treatment of anal fistulas by use of adhesives is an attractive method because of its simplicity and it can be performed on an ambulatory basis. Furthermore, if the treatment is unsuccessful, adhesive use does not subsequently prevent the surgeon from utilizing alternative surgical techniques and/or products. BioGlue Surgical Adhesive is a two-component surgical adhesive composed of bovine serum albumin and glutaraldehyde. We evaluated the usefulness of BioGlue for the treatment of high transsphincter anal fistulas.

METHODS

Patients diagnosed with high transsphincter anal fistulas of cryptoglandular origin, whether relapsed or not, were included in this study. A seton was placed before the injection of BioGlue into the fistula track of high transsphincter anal fistulas in patients with secondary tracts and/or purulent collections. Clinical charts, operative reports, and endoanal echography results obtained for each patient were reviewed.

RESULTS

Fourteen patients (13 males; mean age, 39.9 (range, 24-66) years) with high transsphincter anal fistulas of cryptoglandular origin were recruited into the study. The average time of symptom evolution was 35.6 (range, 2-96) months. Ten of 14 cases were for relapsed fistulas. Six patients required the placement of a seton 37 (range, 32-42) days before the BioGlue injection. Patients were followed for a mean length of 13.92 (range, 3-21) months, and the fistula healed completely in only seven patients (50 percent).

CONCLUSIONS

These preliminary results demonstrate that BioGlue may be useful for treating patients with high transsphincter anal fistulas. Further prospective long-term studies are needed.

Staged mucosal advancement flap for the treatment of complex anal fistulas: pretreatment with noncutting Setons and in case of recurrent multiple abscesses a diverting stoma

OBJECTIVE

To assess the efficacy of a staged strategy for the treatment of complex perianal fistula.

METHODS

Between January 1999 and April 2003 all consecutive patients with complex perianal fistulas were treated according to a staged strategy. Fistula tracks originating from the middle third or upper part of the anal sphincter were included. Patients were examined for recurrent fistulas and complaints of incontinence and soiling. Initial treatment consisted of a noncutting seton with or without a diverting stoma. Definitive surgical treatment consisted of an advancement flap or fistulotomy.

RESULTS

Thirty patients were included (median age; 42 years, range 22-68 years). Seven had Crohn's disease without signs of rectal and anal involvement other than the fistula. At a median follow up of 22 months (range 8-52 months) in 29 (97%) patients, the wounds had healed completely; 7 (22%) patients subsequently developed a recurrent fistula and minor soiling occurred in 7 (23%) patients.

CONCLUSION

Initial treatment with a seton with and without a diverting stoma minimizing inflammatory activity at the fistula site before definitive surgical treatment gave good results in this difficult group of patients.

Experimental model of fistula-in-ano

PURPOSE

This study was designed to create and evaluate an experimental porcine model of fistula-in-ano.

METHODS

Initial cadaveric dissection enabled refinement of the technique for fistula formation and histoanatomical study of the porcine anal canal. Subsequently, three surgically created fistulas were treated by seton drainage in each of eight male pigs (weight, 38-41 kg). After 26 days, magnetic resonance imaging at 1.5 Tesla was performed and setons removed under general anesthesia, enabling clinical and microbiologic track assessment. Two pigs were killed for histologic fistula track assessment.

RESULTS

Histoanatomical assessment noted a rudimentary internal anal sphincter, together with structures resembling anal glands. Artificial fistulas persisted during seton drainage and were more often associated with fecal than skin-derived organisms compared with both perineal and anal canal swabs (P = 0.002). All six fistulas assessed histologically had a lumen, and abundant surrounding granulation tissue similar to that seen in human fistula-in-ano. Epithelialization was not evident in any track. Fistulas were visualized as high signal tracks using magnetic resonance imaging.

CONCLUSIONS

Porcine anal anatomy resembles that of humans, and an experimental model proved suitable when assessed by magnetic resonance imaging, microbiology, and histologically, which demonstrated abundant granulation tissue. This model could be further used to investigate fistula treatments.