Lay-open fistulotomy was first described by John Arderne, an English surgeon, in the fourteenth century. As the name implies, this technique essentially involves laying open the fistula tract after establishing the path of the fistula from the external opening to the internal opening. This would facilitate drainage of the perianal sepsis and enables the wound to heal by secondary intention. A recent study demonstrated a 3-year recurrence rate of as low as 7 % with this technique (Benjelloun et al. 2013). The key component of this technique involves curetting the fistula tract to eradicate any infected and unhealthy tissue. A variation of the technique involves marsupialisation of the edges to prevent the skin from closing over the wound before healing from the wound bed, thereby reducing recurrence rates. This approach has been shown to be associated with faster wound healing and shorter duration of wound discharge (Ho et al. 1998).

Despite its high success rates, the risk of subsequent faecal incontinence increases if this technique is performed in fistulas with considerable involvement of the external anal sphincter or in patients with predisposing impaired anal continence. It has been reported that mild incontinence occurred in 9 % while severe incontinence is documented in up to 4 % of the patients (Stremitzer et al. 2011). This has a detrimental impact on the patients’ quality of life. Thus, lay-open fistulotomy has gradually fallen out of favour in patients with high anal fistula if considerable amount of anal sphincter muscles would be divided (Mylonakis et al. 2001; Cavanaugh et al. 2002).

First described by Hippocrates, seton placement within the fistula tract, either loosely or tightly, has been around for a long time. It is often used either as a bridging procedure to fistulotomy or a single modality in high complex anal fistula to avoid upfront division of excessive amount of sphincter muscle (McCourtney and Finlay 1995; Memon et al. 2011). There are two ways to insert a seton – draining (loose) and cutting (tight). The primary aim of inserting a seton within the fistula tract is to enable drainage of the sepsis.

Although a draining seton effectively relieves the perianal sepsis, it is often not definitive. A subsequent procedure such as fistulotomy is typically performed when the seton has migrated more superficially. A recent meta-analysis actually highlighted a fistula recurrence rate of 3–5 %, depending on whether the anal sphincters were divided with placement of seton. The group that had their anal sphincters divided had slightly better outcomes. But the faecal incontinence rate was also significantly higher in the group that had their anal sphincter divided compared with those who only had seton without division of sphincters (25.2 % vs. 5.2 %) (Vial et al. 2010).

Conversely, when a cutting seton is used, one of the aims is to exteriorise a deep tract by inducing fibrosis superficial to the seton. This would gradually make the tract more superficial as the seton is tightened sequentially in intervals after its insertion. Apart from significant pain and discomfort arising from the rigidity of the seton coupled with the frequent tightening procedures, the reported incontinence rates are actually considerable in spite of its purported sphincter-sparing properties. The faecal incontinence rate of as high as 12 %, with almost 60 % of patients complaining of minor persistent loss of continence to flatus and fluid, has been reported (Ritchie et al. 2009). This complication is likely secondary to the disruption of the anal sphincters as the tightening process of the seton actually cuts through the sphincters gradually, and the ensuing fibrosis and scarring of the muscle fibres resulted in suboptimal function of the sphincters.

This technique was first described for the repair of rectovaginal fistulas in 1902 which later extended to the treatment of complex anal fistulas. The two primary aims of this technique are to disrupt any communication of the tract with the anal canal and to completely remove the diseased and inflamed tissue from the anal mucosal surface (Elting 1912). A meta-analysis review of the success rate for anal fistula following mucosal advancement flap procedures revealed a recurrence rate from 7.0 to 51.7 %, while the wound healing time was reported to be 24.5 (±5.5) days. The incontinence rate was documented to be from 3.7 to 13.4 %. But as this technique is typically reserved for mainly the recurrent and/or complex high anal fistulas, one would expect their success rates to be less than first-line options such as fistulotomy.

One of the limitations precluding its widespread adoption is the technical difficulties in mastering this procedure. A thorough understanding of the anal anatomy and the underlying pathology is critical to maximise the success and minimise its complication rates (Golub et al. 1997; Leng and Jin 2012). To pursue a higher success rate for this technique, some surgeons have combined the mucosal advancement flap with the administration of platelet-rich plasma which is an autologous form of tissue glue. A 16.0 % recurrence rate after a median follow-up period of 27 months was reported which did not appear to improve the procedural outcome significantly (Göttgens et al. 2014).

The problems of the aforementioned techniques are apparent. Anal fistulas involving minimal sphincter muscles can be easily dealt with by the fistulotomy procedure. But none of the “traditional” methods have been deemed safe and effective in the treatment of high, complex and recurrent anal fistulas. With the continual advancement in science and technology, newer and innovative techniques have been introduced with the aim to improve the success rates following the treatment of this difficult condition while preserving the anal sphincter function.

Despite the prominence and keen interest in adopting technology and innovation in treating anal fistula, their outcomes have yet to reach levels comparable to conventional treatment modalities. Perhaps, success in fistula surgery may not necessarily lie with continual advancement in technology and innovation.