BACKGROUND: Bladder outlet obstruction can have devastating consequences. Given the poor outcome, in utero intervention has been advocated in attempt to salvage pulmonary and renal function. Currently, several methods for urinary decompression have been utilized. However, these procedures are fraught with technical problems or are associated with high fetal loss rate and maternal morbidity. The recent development of minimal access fetal surgery provides a promising alternative to the traditional fetal interventions. However, transuterine fetal vesicostomy is a technically demanding procedure limited by the inability to perform freehand laparoscopic suturing within the restricted uterine space. We evaluated whether by adapting current robotic-assisted laparoscopic techniques to access the fetus in utero, laparoscopic decompression of the obstructed bladder can be performed efficiently.
METHODS: At 95 days of gestation, thirteen fetal sheep underwent ligation of the urethra and urachus. Two days later, a robotic-assisted laparoscopic vesicostomy was performed on the fetal sheep to decompress the bladder. US evaluation of the kidneys and bladder were performed before and after the each of procedures. The fetuses were then delivered at 135 days of gestation. Post-delivery, US evaluation of the urinary tract was utilized to access the adequacy of the bladder decompression and the patency of the vesiscostomy was assessed morphologically.
RESULTS: After 48 hours of undergoing ligation of the urethra and urachus, all fetuses had bilateral moderate hydronephrosis and a markedly distended bladder. In the first 5 animals, the vesiscostomy could not be completed laparoscopically due to limitation in visualization. To solve these issues, modifications in surgical techniques were developed to better access and maintain distension of the uterus. Subsequently, in the next 4 fetuses, the vesicostomy was partially completed laparoscopically; the procedure could not be completed due to the long surgical time. Additional modifications in trocar placement and instrument design allowed vesicostomy to be completed laparoscopically in the last 4 fetuses with a surgical time of 2.5 to 4 hours. Decompression of the urinary tract and patency of the vesicostomy were observed in all of these fetuses, postoperatively.
CONCLUSIONS: We developed specific modifications in current robotic-assisted laparoscopic techniques and instrumentation to allow for the in utero treatment of bladder outlet obstruction. This procedure can be performed efficiently and may provide advantages over conventional surgeries for fetal intervention.