Design and development of adapters for electromagnetic trackers to perform navigated laparoscopic radiofrequency ablation

Philipp Hildebrand¹ , Armin Besirevic¹ , Markus Kleemann¹ , Stefan Schlichting¹ , Volker Martens² , Achim Schweikard² and Hans-Peter Bruch¹

¹University of Schleswig-Holstein, Campus Lübeck, Department of Surgery, Ratzeburger Allee 160, Lübeck, 23538, Germany

²University of Lübeck, Institute for Robotics and Cognitive Systems,, Ratzeburger Allee 160, Lübeck, 23538, Germany

author email corresponding author email

Annals of Surgical Innovation and Research 2007, 1:7doi:10.1186/1750-1164-1-7


Published:	31 October 2007

Abstract

Background

Laparoscopic radiofrequency ablation (RFA) is an accepted approach to treat unresectable liver tumours distinguishing itself from other techniques by combining minimal invasiveness and the advantages of a surgical approach. The major task of laparoscopic RFA is the accurate needle placement to achieve complete tumour ablation. The use of an ultrasound-based, laparoscopic online-navigation system could increase the safety and accuracy of punctures. To connect such a system with the laparoscopic ultrasound (LUS) transducer or the RFA needle especially designed adapters are needed. In this article we present our first experiences and prototypes for different sterilizable adapters for an electromagnetic navigation system for laparoscopic RFA.

Methods

All adapters were constructed with the help of a standard 3D CAD software. The adapters were built from medical stainless steel alloys and polyetherketone (PEEK). Prototypes were built in aluminium and polyoxymethilen (POM). We have designed and developed several adapters for the connection of electromagnetical tracking systems with different RFA needles and a laparoscopic ultrasound transducers.

Results

Based on earlier experiences of the initial version of the adapter, sterilisable adapters have been developed using biocompatible materials only. After short introduction, the adapters could be mounted to the laparoscopic ultrasound probe and the RFA needle under sterile conditions without any difficulties. Laboratory tests showed no disturbance of laparoscopic navigation system by the adapters. Anatomic landmarks in the liver could be safely reached. The adapters showed good feasibility, ergonomics, sterilizability and stability.

Conclusion

The development of usable adapters is the prerequisite for accurate tracking of a RFA needle for laparoscopic navigation purposes as well as 3D navigated ultrasound data acquisition. We designed, tested and used different adapters for the use of a laparoscopic navigation system for the improvement of laparoscopic RFA.