Abstract—Computer-assisted surgical devices, including laparoscopic surgical robotic arms, can be used in urologic surgery to minimize trauma. In this study, we explored the feasibility and applicability of using a robotic arm, AESOP (Computer Motion Inc, Goleta, CA), as a substitute for surgical assistants during hand-assisted laparoscopic nephrectomies in humans. Four patients (3 men and 1 woman, mean age 66 years) underwent robotic-assisted laparoscopic nephrectomy. The hand-assisted laparoscopic nephrectomy was completed successfully in all patients. The average operative time, estimated blood loss, and time to hospital discharge was 252.5 minutes, 0.57 ml, and 4.5 days, respectively. Postoperative satisfactory function was confirmed through laboratory tests, imaging exams and biochemical tests. No complications were reported for any of the patients. Parameters, such as the operative time, are expected to be further reduced when more experience with the use of the robot has been acquired. In conclusion, robotic-assisted laparoscopic nephrectomy is feasible and safe, and can be performed without complications. The potential long-term cost effectiveness of using robotic surgical assistants in laparoscopic surgery highlights the economic impact of this research and warrants further investigation. Keywords—Computer-aided surgery, robotics, laparoscopy, urology I. INTRODUCTION Laparoscopic nephrectomy is indicated for the treatment of most benign renal diseases and it provides many advantages over open nephrectomy [1]. Despite the obvious advantages with comparable cancer control, these procedures have yet to become the standard of care. One explanation may be the difficulty of performing laparoscopy to remove large lesions. Hand-assisted laparoscopy (HAL), the insertion of the hand into the laparoscopic surgical field while maintaining visualization and the pneumoperitoneum, is a novel technique aimed to assist standard laparoscopy when large tumors are removed from the abdomen [2]. Compared with standard laparoscopy, the advantages of HAL include reduction of operative time, greater control by the surgeon, and facilitation of particularly difficult procedures, such as partial nephrectomy for a large tumor [3]. The disadvantages of HAL include possible gas leakage through the specialized devices, less favorable cosmesis of the incisions and longer convalescence [4]. In addition to these, the surgeon’s dexterity is significantly impaired due to the use of the hand port. Consequently, the presence of an experienced assistant responsible for positioning the laparoscope is necessary. The assistant’s task requires keeping the surgical point of interest in the center of the video frame, providing an appropriate magnification and maintaining a horizontal image. Since many hand-assisted laparoscopic procedures are long, fatigue of the assistant’s hand may lead to reduced positioning accuracy and bring anxiety into the operating room. The use of positioning devices allows direct control of the whole procedure to the operating surgeon. This increases precision of action and reduces cost [5]. Robotic control in hand-assisted laparoscopic nephrectomy in humans– a pilot study P.Chatzilias 1 , Z.Kamarianakis 2 , S.Golemati 2 , and M.Christodoulou 2 1 Department of Urology, Hospital of Chania, Crete, Greece 2 Department of Electronic and Computer Engineering, Technical University of Crete, Greece Various robotic positioners and stabilizers have been developed, where a robot-holding surgical tool is controlled so as to follow the surgeon’s commands [6], [7]. The role of the robot is to filter out tremors and disturbances of the surgeon’s hands, so as to enhance the precision and mechanical stability of the operation. Various specialized robotic tools have also been proposed [8], [9]. It is important to note that in the various robotic surgical assistant systems described above, the surgical procedures are still completely performed by the human surgeon. The human commands are mimicked by the robotic device through computer control. The virtual presence, through visual feedback to the surgeon, creates a sensation that the surgeon is operating the tool tip instead of the tool handle, thus reducing one of the challenges of minimally invasive surgery. Robots are increasingly utilized in urology [10], [11]in part, because of favorable performance characteristics. Robots perform tasks quickly with excellent precision. They do not fatigue regardless of time or environment and can be more cost-effective than humans. The function of robots, however, remains heavily influenced by human factors. Indeed, industrial and medical robots function only as well as software or operators controlling the devices. Recently, performance-enhancing robots were introduced to increase clinical applicability of laparoscopy. Robotic control has been used in a number of hand- assisted laparoscopic surgical procedures [12], [13]. However, to the best of our knowledge, robotic control has not been previously used in hand-assisted laparoscopy. The purpose of this study was to explore the feasibility and applicability of using a robotic arm in difficult laparoscopic procedures, such as hand-assisted laparoscopic nephrectomy, in humans. II. METHODOLOGY A. AESOP robotic system 0-7803-8439-3/04/$20.00©2004 IEEE 2742 Proceedings of the 26th Annual International Conference of the IEEE EMBS San Francisco, CA, USA • September 1-5, 2004