ABSTRACT
The embryogenesis of rectal duplication cysts is attributed to a ‘pinching off ’ of a diverticulum in the 20-30 mm embryo,85 in contrast to the ‘caudal twinning’ which occurs in the 10 mm embryo and is associated with complex hindgut anomalies.86,87
Presentation of the cysts depends on: (1) size and their mass effect, (2) fistulas, (3) infection, (4) ulceration if they contain gastric mucosae, and (5) malignancy.88 The duplication cyst usually forms in the retrorectal space and contains colorless mucus, which can become infected. They frequently present in 20-45% of cases.84,85
No cases of a fistula between the rectum and urinary tract have been described. Malignant degeneration has been reported in the rectal duplication from the fourth decade onwards.89,90
Treatment of the rectal duplication cyst is surgical excision or fenestration of the common wall. Depending on the anatomical variations, a transanal or transcoccygeal (Kraske) approach can be employed. For longer or more complicated cysts, a longer posterior sagittal incision will provide better exposure. As with other duplications, it is of prime importance to remove all mucosae in the duplication. The muscularis can be left in situ.
