Newer advances in access

Abstract

This chapter starts with an overview of the commonly used access direction technologies namely fluoroscopy and ultrasonography. Then an overview of the main novel technologies for access has been provided starting from visual inspection of the access tract using the optical needle. The optical needle has a primary success rate of only 66% in targeting the desired calyx on the first attempt. Then, fluoroscopy-based novel technologies including three-dimensional reconstruction of the access tract anatomy using preoperative computed tomography data by Urodyna CT and other fluoroscopy-based technologies have been reviewed. Urodyna CT has been associated with a high dose of radiation to the patient and also with a steep learning curve. iPAD-assisted PCNL reconstructs bodily organs using preoperative CT scan and uses augmented reality to reveal access tract of PCNL and organs within it by an iPAD software. Afterward, novel ultrasonography-based technologies including 3D ultrasonography, use of Doppler ultrasonography for improvement of access, and the combination of ultrasonography with electromagnetic navigation have been overviewed. The best success rate of ultrasonography has been observed with Sonix GPS technology which resorts to both ultrasonography and electromagnetic navigation and with a first attempt success rate of 100%. Afterward, the concept of electromagnetic navigation has been presented. Electromagnetic navigation has been associated with a 100% success rate on the first attempt in a preliminary study on human subjects and is a promising technology in the future.