**7. Perianal Crohn's disease**

Crohn's disease (CD) is an idiopathic, incurable chronic inflammatory disease of the GI tract [92–95], associated in more than 30% of cases to symptoms of perianal disease (PAD) [96–98]. The risk of developing PAD is consistent with the time from the diagnosis of CD, from 20% after ten years and up to 30% after twenty years. However, PAD is far more common in patients with colon (41%) and rectum (90%) localization and less in patients with ileal disease (12%) [99–102]. Early diagnosis and correct treatment are crucial to allow patients to promptly start medical treatments with antitumor necrosis factor (tnf) which is considered the cornerstone of treatment, offering the best long-term control of PAD [103–116].

The gold standard to assess symptomatic perianal disease (PAD) in CD patients is the exploration of the anal canal and distal rectum under anaesthesia (EUA) [117–122]. EUA usually allows a correct diagnosis of fistulous tracts, a classification of the fistula, and an appropriate treatment of the PAD at the same time. In tertiary centres, PAD treatment can be performed also in an outpatient setting by expert surgeons. Whether to perform an EUA or an outpatient exploration (OE) depends on the anatomy, the type of fistula, and finally, the surgeon's expertise [123–129]. Moreover, active proctitis control must be achieved whenever possible prior to any surgical treatment. Treatment strategy and procedures are different in an acute or in an elective setting; in acute management, the main aim is sepsis control: incision and drainage of every abscess are strongly advised, while placement of a loose seton should be considered only if the fistulous tract can be promptly and easily identified [120]. In an elective setting, an exploration of the anal canal and distal rectum under anaesthesia is recommended and, in case of complex fistula, even in the presence of proctitis, a loose, draining seton could be passed if the internal and external orifices of the fistulous tract are found. A fistulotomy or fistulectomy can be safely considered for simple posterior fistulas [133].

Perianal fistulas in CD may be simple or complex according to the American Gastroenterological Association (AGA) [130–133]. Simple fistulas have a high healing rate, while complex fistulas are difficult to treat and show a poor healing rate and increased rate of relapse.

The aim of the surgical treatment of PAD in CD patients should be symptoms or complication control, allowing patients to pursue a timely medical therapy, in a multidisciplinary management. In the presence of a symptomatic perianal fistula, an optimal result can be considered to avoid sepsis, allowing for a good drainage

#### *Ambulatory Surgery for Perianal Disease DOI: http://dx.doi.org/10.5772/intechopen.97119*

before thinking to the complete healing of the fistula and finally preventing the recurrence and preserving the continence of the anal sphincter. It is essential to ensure timely treatment, because perianal fistulas significantly impair the quality of life of the patients, to avoid the potentially disastrous consequences such as those of an undrained sepsis or ramification of the fistulous tracts [134–139]. Only the patients with symptomatic Crohn's anal fistula should undergo a surgical treatment. The gold standard treatment for symptomatic perianal disease in CD patients is conducted during the EUA. Most of the series available in literature refer to day surgery or overnight admission. Unfortunately, a timely treatment is not always possible and this, as said, may well represent a relevant clinical issue.

According to the Association of Coloproctology of Great Britain and Ireland consensus conference on surgical management of fistulating perianal Crohn's disease, experienced surgeons should always try to place a seton when the fistulous tract is readily identifiable and this should be possible most of the times in "skilled hands". Compliance of patients to the procedure was high and, from a surgical point of view, the OE was nice to perform without difficulties or trouble in all cases.

This procedure should be offered in a high-volume center in which a multidisciplinary dedicated team is available. In selected cases, OE may be offered as a "bridge to surgery," able to faster solve critical clinical issues or palliate disabling symptoms with low morbidity and discomfort, also allowing patients to continue medical therapy. OE can be repeated, if necessary, in different occasion. From an economical point of view, the OE can definitively save logistics and money. The OE surely is a minimally invasive approach, with low morbidity and very low patient stress. OE could be a safe and effective procedure that can be proposed to the vast majority of patients with Crohn's fistulas. It is not recommended in nonexperienced hands and in high complex or rectovaginal fistulas (Hughes classification 1b, 1d or 2d, and 2e).
