Acute supralevator abscess: the little we know

Acute supralevator abscess (SLA) is an uncommon and complicated form of anorectal sepsis. Its correct management is crucial to avoid complex iatrogenic fistula formation. A comprehensive review of the literature was conducted to determine the incidence of SLA and the surgical outcome with particular reference to the direction of drainage.

A search of Medline, PubMed and the Cochrane Library was performed to identify all studies reporting surgical drainage of SLA.

A total of 19 studies were identified, including 563 patients. The only two prospective studies reported an incidence of SLA of 10% and 3% in 68 and 100 patients, respectively, with anorectal sepsis. In 17 retrospective studies, the incidence ranged from 0% to 28%. Magnetic resonance imaging (MRI) was performed routinely in only one study. The surgical anatomical classification of the abscess was described in six studies diagnosed at surgery. The direction of surgical drainage whether 'inwards' (into the lumen) or 'outwards' (into the ischioanal fossa) was stated in only six studies. In two of these, the direction of drainage was contradictory to the recommendation made by Parks et al. Recurrent sepsis was reported in eight studies and ranged from 0% to 53%.

Detailed and prospective data on acute SLA are lacking. Its real incidence is unclear and it is not possible to analyse surgical outcomes conclusively according to different direction of drainage. The routine use of MRI in complicated anorectal sepsis would specify the surgical anatomy of SLA before any drainage is carried out.