Simulation of Supralevator Abscesses and Complex Fistulas in Cadavers: Pelvic Dissemination and Drainage Routes

BACKGROUND: Most perianal abscesses have a cryptoglandular origin, following the pathogenesis described by Parks in 1961. Supralevator abscesses have the most uncommon location. Nevertheless, such pathology results in a high morbidity because of their difficult diagnosis and treatment. OBJECTIVE: This study aimed to deepen the knowledge of the pathogenesis and management of supralevator abscesses, as well as the complications derived from incorrect treatment, by using simulation in cadavers. DESIGN: This study is an anatomosurgical description of pelvic and perianal zone and simulation of the different types of supralevator abscesses, their correct drainage routes, and secondary complex fistulas due to incorrect drainage. SETTINGS: This dynamic article is based on cadaveric simulation. PATIENTS: Three cadaveric pelvises (2 male and 1 female) were prepared in formalin and sagittally sectioned, and one perineal dissection was performed of a fresh male pelvis. This is an iconographic description of 3 patients treated for supralevator abscesses in our colorectal surgical unit. MAIN OUTCOME MEASURES: The virtual anatomical spaces map out a correct treatment. RESULTS: We reproduced the origin of the different types of supralevator abscesses, as well as their locations and possible drainage pathways, and we determined the definitive treatment of secondary fistulas and their morbidity due to their incorrect drainage. LIMITATIONS: The limitations of this study are inherent to anatomical studies without real case intervention. CONCLUSIONS: A proper anatomical knowledge of the supralevator abscesses and surgical training by using cadaveric simulations could improve the diagnostic criteria, facilitate the correct decision on surgical drainage pathways, and, thus, decrease postoperative morbidity in patients with this disease.