Amnioscopic endofetal illumination with infrared-guided fiber

Minimally invasive amnioscopic surgery has several potential advantages over traditional open hysterotomy, including the reduction of the risk of preterm labor and spontaneous abortion. Adequate visibility of the fetal target organ is obligate to the success of in utero procedures. This is a preliminary report on the use of an end-emitting infrared fiber (750 microns; 810-nm wavelength) that allows image fusion with Infravision videocamera systems (Gabriel Medical, Lafayette, LA). Once placed, this fiber can serve as a homing beacon to identify the fetal bladder in the surgical creation of an amnioscopic vesicostomy for the relief of obstructive uropathies. Under general endotracheal halothane anesthesia, amnioscopic access was established in time-dated pregnant ewes using one 3.7-mm and two radially dilating 2-mm to 5-mm trocars. This access allowed the investigation of several methods of intravesicular infrared fiber placement. Ultrasound-guided direct needle puncture is the quickest method of accessing the fetal bladder but is unreliable when the bladder is empty. Accurate placement of the access needle directly over the suprapubic region was accomplished with amnioscopic assistance. The fiber was also placed transurethrally in one female and one male fetus, with subsequent perforation of the female's bladder. Successful infrared bladder illumination was accomplished in all animals. The fusion integration of this camera system allows simultaneous viewing by visible spectrum and near-infrared wavelengths. We believe that this system provides a further degree of safety for amnioscopic procedures.