V7-01: Intraoperative MRI-Guided Navigation of the Pelvic Floor During Exstrophy Closure
Radical dissection of the urogenital fibers and the thickened smooth and striated muscle fibers connecting the posterior urethra and bladder plate to the diastatic pubic rami is crucial for adequate placement of the posterior vesicourethral unit deep within the pelvis during classic bladder exstrophy (CBE) and cloacal exstrophy (CE) closure, as well as ensuring successful outcomes. Intraoperative magnetic resonance imaging (MRI) guided navigation of the pelvic floor offers a novel technique for identification of the urogenital diaphragm fibers and the thickened muscular attachments between the posterior urethra, bladder plate and pubic rami during CBE closure.
Institutional review board and Food and Drug Administration approval was obtained for use of Brainlab® (Munich, Germany) intraoperative MRI-guided navigation of the pelvic floor anatomy during closure of CBE at the authors’ institution. Pre-operative pelvic MRI was obtained one day prior to exstrophy closure in patients necessitating pelvic osteotomies. Intraoperative registration was performed after pre-operative planning with a pediatric radiologist utilizing five anatomic landmarks immediately prior to initiation of surgery. Accuracy of identification of pelvic anatomy was assessed by three pediatric urologic surgeons and one pediatric radiologist.
32 patients with CBE and 2 patients with CE closed at the authors’ institution have successfully utilized Brainlab® technology to navigate and guide the dissection of the pelvic floor intraoperatively. All patients had 100% accuracy in correlation of gross anatomic landmarks with MRI identified landmarks intraoperatively, and all have had successful closure without any complication.
Brainlab® intraoperative MRI-guided pelvic floor navigation and dissection is an effective way to accurately identify pelvic anatomy during CBE and CE closure. Future assessment of real-time changes in pelvic floor anatomy comparing pre-closure to post-closure MRI will allow quantification of pelvic floor anatomy in these patients and may allow for intra-institutional telementoring in this most important first step of exstrophy reconstruction.