The Monti procedure: applications and complications

Abstract

In 1980, Mitrofanoff1 succeeded in obtaining urinary continence by implanting small-diameter tubes into neurogenic bladders using a bladder antireflux technique. Emptying was obtained by clean intermittent catheterization. In 1986, Duckett and Snyder2 expanded this concept by emphasizing the need for a urinary reservoir with good compliance into which the ureters were implanted using an antireflux technique. This set of procedures for the construction of a continent urinary diversion was called the “Mitrofanoff principle.” Additional studies have shown that the success of the procedure is not dependent on the underlying urologic disease. Also, it does not depend on the type of efferent tube and its possible peristalsis. Neither does it depend on the type and configuration of the reservoir nor on the age of the patient. However, it does depend on the maintenance of a positive pressure gradient between the conduit lumen in the antireflux tunnel and the reservoir.3–6 Because of the relatively easy execution of the “Mitrofanoff principle” and the high degree of continence obtained with its use, its use has widely increased and it has been applied in pediatric urology.7 However, the critical problem since the beginning was the choice of a catheterizable efferent conduit. This conduit should be constantly available, providing complete continence and easy catheterization, with a low rate of complications. It should have an appropriate caliber for mucus drainage and endoscopic manipulation, and it should be easy to perform.8 Mitrofanoff1 considered the cecal appendix, a dispensable organ of undefined function, the ideal structure to be used as a conduit. The appendix has a predictable blood supply. It is easily mobilized and its average size is 4 to 5 cm in newborns and 9 to 10 cm in adults, long enough for this proposed use. The appendiceal diameter is uniform throughout its extension and in most cases allows the passage of at least a 10F catheter.9 In view of these characteristics, the appendix became the reference standard for this function and was more frequently used separated from the cecum, with the distal end implanted into the reservoir and the cecal end in the skin.3,4,10,11 It was also used in situ with or without an antireflux tunnel or invaginated into the cecum when the latter was included as part of the reservoir.12–15 When the structure was too short, it was lengthened with a cecum flap16; in other cases, it was implanted in a free mode into the reservoir.17 The appendix was also divided in the middle, allowing the simultaneous preparation of the continent urinary diversion and Malone antegrade continence enema (MACE).10