Recent Advances in Anal Disorders

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During the last decade several advances have been achieved regarding the etiology, diagnosis and treatment of anal disorders. Laser Doppler flowmetry, for example, has revealed that increased tone of the internal anal sphincter is associated with a decrease in anodermal bloodflow, especially at the posterior midline. Treatment of chronic anal fissure by lateral internal sphincterotomy results in a significant pressure drop with a concomitant increase of anodermal bloodflow at the fissure site. Based on these and other findings chronic anal fissures are considered at present as ischemic ulcers. It has been shown that nitric oxide mediates the relaxation of the internal anal sphincter. The activity of this sphincter can be influenced by local application of exogenous NO-donors such as GTN and ISDN. The potential role of these drugs in the treatment of anal fissure will be discussed. Headache is the most important drawback of these NO-donors. Therefore attention is focused on other agents such as Botox, Indoramin, Calcium channel blockers and L-Arginine.
Other advances have been achieved in the diagnosis and treatment of perianal fistulas. Preoperative assessment of fistulas has been improved significantly since the introduction of hydrogen peroxide enhanced endoanal ultrasound and endoanal MRI. For the treatment of high transsphincteric fistulas new techniques have been developed in order to minimize sphincter damage and to prevent continence disturbances. The transanal advancement flap repair, the muscle filling procedure according to Iwadare and the use of fibrin glue represent these new techniques. For patients with fecal incontinence several new treatment modalities are now available such as dynamic graciloplasty, sacral neuro-modulation, implantation of silicone biomaterial and the Secca procedure. All these new techniques illustrate that many advances in anal disorders have been achieved in recent years.