Posted 4/10/2019 6:15 PM (GMT 0)
Hi DBrookenz, below are the UK ASSOCIATION OF COLOPROCTOLOGY OF GREAT BRITAIN AND IRELAND recent guidelines on Fibrin Glue. Hope you find it useful:
Fibrin glue
Findings
The use of fibrin glue to treat anal fistulas is associated with variable success, but does not threaten continence. It remains uncertain as to which fistulas are suitable for fibrin glue treatment. Success (fistula healing) is low when the fistula track is short. (Level I)
Recommendations
With variable and mostly low rates of healing, fibrin glue is not recommended for routine use in anal fistulas, but may be considered where other surgical options are not feasible. (Grade C)
Various autologous and commercial preparations of fibrin glue have been used to treat anal fistulas. Autologous glues are formed from the patient's own blood, whilst commercially available glues are a mixture of clotting factors, aprotinin and calcium (Beriplast; CSL Behring, Pennsylvania, USA; Tisseel; Baxter Healthcare, Deerfield, Illinois, USA), or are synthetic glues, such as cyanoacrylate (Glubran; GEM SRL, Viareggio, Italy). The glues are applied to fill the fistula track and provide a bridge for fibroblasts and stromo‐vascular cell in‐growth to produce healing. Their ease of use, minimal risk to continence and repeatability make them an attractive option, especially in patients at high risk of sphincter dysfunction 150, 151.
A wide range of healing rates with fibrin glues have been reported, ranging from 14% to 94% 152, 153. Variability in disease complexity, fistula anatomy and surgical technique makes comparison of the results from randomized trials difficult to interpret 154-156. A meta‐analysis has not shown any statistical difference with the use of fibrin glue, compared to other conventional surgical treatments, in terms of fistula recurrence or incontinence 157.
Some authors have reported better healing rates in longer tracks, suggesting that shorter tracks (< 3.5 cm) are less likely to retain the glue 155, 158, but this has been contradicted in other reports 159-161. Technical errors have been suggested for failure, including inadequate curettage and washout to remove all infected and epithelialized tissue 155, 161, 162, or incomplete filling of the track with the glue to ensure occlusion 155.
Like other fistula treatments, recurrence rates with fibrin glue increase with the length of follow‐up. A long‐term follow‐up study showed that up to 26% of patients who were symptom free at 6 months went on to develop recurrence at an average of 4.1 years 163. However, on several occasions the recurrence was at a different site, suggesting that a new fistula had formed. The highest probability of failure appears to occur in the first 6 months following treatment, so 6 months should be the minimum follow up period 152, 161, 164, 165.
A multicentre trial randomized patients to fibrin glue or seton treatment for transsphincteric fistulas and showed a 38% healing rate in the fibrin glue group, compared with 87% in the seton group 150. Patients who had a recurrence after fibrin glue were further randomized to repeat glue treatment or a loose seton. A further 50% healed with repeat glue treatment. Notably, there was a significant worsening in the Cleveland Clinic continence score in the seton group. Many studies have investigated the use of repeat glue application to increase healing rates, even up to four applications 166. A prospective study of fibrin glue for simple transsphincteric and intersphincteric fistulas showed that repeat glue treatment decreased the overall recurrence rate from 23% to 7.6% 167. Conversely, other authors have reported that repeated applications of fibrin glue are unlikely to succeed 168 and other studies have shown an adverse outcome when fibrin glue is combined with an endorectal advancement flap 169.
Various strategies have been suggested to improve the healing rates with glues. Local sepsis should be eradicated with the use of preoperative setons, the track should be thoroughly curetted and the track irrigated with either saline or hydrogen peroxide. Preoperative bowel preparation has not consistently shown a benefit. Suturing the internal or external openings shut has been advocated, but not shown to confer a significant benefit 152.
It has been suggested that high failure rates with the glue may be a consequence of the glue not being retained in the fistula track 170, 171. To overcome this, some authors have recommended the use of stool softeners and avoiding straining and exercise in the postoperative period, although there are no data to support this. Other explanations for failure of fibrin glue include early resorption/degradation within 5–10 days of application, providing insufficient time for established healing 165, 171. A Phase I trial using Permacol® glue, which incorporates fibres suspended in fibrin glue to provide a physical scaffold for host cell proliferation after glue absorption, has shown promising results, but more, randomized, data are required 165. Newer autologous fibrin sealants have not shown any increased efficacy compared with conventional glues, with healing rates of up to 40% 172. Research continues into the use of stem cell autologous suspensions for fistula application and the ADMIRE CD study used fibrin glue as the scaffold for allogeneic mesenchymal stem cell treatment of Crohn's anal fistulas 173. This may represent the main role for fibrin glue in the future.