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Microrobot Assisted Laparoscopic Urological Surgery in a Canine Model
Microrobot Assisted Laparoscopic Urological Surgery in a Canine Model Jean V. Joseph,* Dimitry Oleynikov, Mark Rentschler, Jason Dumpert and Hitendra R. H. Patel From the University of Rochester Medical Center (JVJ, HRHP), Rochester, New York, University of Nebraska Medical Center (DO), Omaha and University of Nebraska Walter Scott Engineering Center, Lincoln, Nebraska, and University College Hospital, London, United Kingdom
Purpose: Robotic technologies have had a significant impact on surgery. We report what is to our knowledge the first use of microrobots to perform laparoscopic urological surgery in a canine model. Materials and Methods: Nonsurvival laparoscopic radical prostatectomy and radical nephrectomy were performed using microrobotic camera assistance. Following the administration of general anesthesia miniature camera robots were inserted in the insufflated abdomen via a 15 mm laparoscopic port. These microrobots were mobile, controlled remotely to desired locations and provided views of the abdominal cavity, assisting the laparoscopic procedures. Additional ports and laparoscopic instruments were placed in the abdomen using the views provided by these microrobots. Results: One dog underwent laparoscopic prostatectomy and another underwent laparoscopic nephrectomy. The 2 procedures were completed successfully. Microrobots provided additional views from several angles, aiding in the performance of the procedures. Conclusions: Miniature camera robots (microrobots) provide a mobile viewing platform. With added functionality these new robots have the potential to further evolve the robotic armamentarium for surgeons. Key Words: prostate, dogs, robotics, laparoscopy, prostatectomy
aparoscopy is steadily gaining ground in urology. To date there is hardly a urological procedure that has not been attempted laparoscopically in the quest by urologists to provide patients with less invasive alternatives. While some procedures are widely performed laparoscopically, others are only performed at highly specialized centers due to the difficulty associated with laparoscopic instrumentation and techniques. The advent of the robot has helped surgeons overcome some of the limitations of pure laparoscopic surgery. The robot provides a number of advantages, such as a stereoscopic 3-dimensional view of the surgical field and improved hand-to-eye coordination, allowing the surgeon enhanced dexterity in performing tasks that remain complex using pure laparoscopic techniques. While the robot has removed certain limitations of laparoscopic surgery, it has added a number of others. With the surgeon displaced from the patient bedside no haptic feedback is provided to allow the assessment of tissue consistency, which has been a major source of criticism from opponents of robotic surgery. Similar to laparoscopic surgery, the cameras used in robotic surgery rely on a fixed port system, constrained to only 4 df, potentially limiting the view.
L
Submitted for publication January 23, 2008. Study received institutional review board approval. * Correspondence: Section of Laparoscopy and Robotic Surgery, Department of Urology, University of Rochester Medical Center, 601 Elmwood Ave., Box 656, Rochester, New York 14642 (telephone: 585-341-7795; FAX: 585-756-5457; e-mail: jean_joseph@ urmc.rochester.edu).
See Editorial on page 1881.
0022-5347/08/1805-2202/0 THE JOURNAL OF UROLOGY® Copyright © 2008 by AMERICAN UROLOGICAL ASSOCIATION
The use of microrobots to assist with laparoscopic surgery has been previously reported in the general surgical literature.1 Their mobility inside the abdominal cavity provides an unparalleled view of the surgical field.1,2 We report the use of microrobot cameras to assist with laparoscopic urological surgery in a canine model. MATERIALS AND METHODS A collaborative research agreement was executed between researchers from the University of Rochester Medical Center, University of Nebraska and University College London Institute of Urology to build microrobot prototypes to assist with laparoscopic canine prostatectomy and nephrectomy. Two microrobot camera prototypes were used in this study. The pan and tilt microrobot is capable of rotation along 2 separate axes, which allows it to pan the operative field through 360 degrees and tilt upward or downward at ⫾45 degrees. Separate motors activate the pan and tilt motions. The assembled device consists of a small cylindrical tube with a diameter of 15 mm and a height of 3 inches. The lens and light source are positioned on top of the cylinder that houses the motor gears. The platform legs attached to the base are abducted by torsion springs, allowing the microrobot to stand. The prototypes were tethered with the cord exiting the abdominal cavity adjacent to the midline trocar (fig. 1). The second prototype used was the crawler (fig. 2). This prototype is also mobile. It consists of 2 cylindrical wheels capable of navigating to desired locations in the abdominal cavity. It is equipped with a lens in the middle of the cylinders, providing close-up views of the surgical site. Each type
2202
Vol. 180, 2202-2205, November 2008 Printed in U.S.A. DOI:10.1016/j.juro.2008.07.016
MICROROBOT ASSISTED LAPAROSCOPIC UROLOGICAL SURGERY IN CANINE MODEL
2203
FIG. 1. Pan and tilt prototype
of robot is tethered for power and maneuvered using a joystick. Under an institutional review board protocol 2 male dogs were anesthetized according to a standard protocol by licensed veterinarians. After induction a Veress needle was used to insufflate the abdomen using carbon dioxide up to a pressure of 12 mm Hg. A supraumbilical 15 mm midline port was used to insert the microrobot cameras inside the abdominal cavity. Only 1 microrobot was used at a time. Additional ports were placed to facilitate laparoscopic radical prostatectomy and nephrectomy. Conventional laparoscopic instruments were used to perform the procedures. RESULTS The 2 procedures were completed successfully. Miniature camera robots were used in conjunction with a standard endoscope. Video images provided by the microrobot were fed to a separate monitor. The pan and tilt camera was
placed in the abdominal cavity at desired sites using standard laparoscopic instruments for placement at specific locations. Pan and tilt functions were activated using the control joystick. The crawler was advanced to different locations remotely, also using a joystick (fig. 3). After the cameras were inserted in the abdomen they were used to view the abdominal wall, assist with proper trocar placement and eventually perform the procedure. The microrobots assisted with planning trocar positioning. They provided the surgeon with a multitude of viewing angles. The microrobots were used to assist with the completion of prostatectomy and nephrectomy. The microrobot camera views provided the surgeon with an additional frame of reference that is not available with the standard endoscope. Figure 3 shows a view of the renal hilum from the standard endoscope and a side view from the pan and tilt microrobot. Figure 4 shows the control joystick and the operating room setup. DISCUSSION
FIG. 2. Crawler prototype
Microrobot prototypes have been previously studied in inanimate and animal models.1,2 To our knowledge this study represents the first use of these devices in urological surgery. These successful prototypes are capable of providing additional views of the surgical field and they may further advance the use of robots in surgery. The pan and tilt robot provides a 360-degree view of the abdomen while the surgeon maintains a view of the surgical field through the standard laparoscope. Similar to the crawler prototype, which can be advanced to specific locations, it can provide posterior views of an organ or surgical site that are not possible via current laparoscopic or robotic cameras using a stationary viewing platform. In 2001 robot use debuted in urology.3 Groups from a number of institutions have reported large successful series incorporating this technology in various surgical procedures. Since the initial reports of laparoscopic radical prostatectomy in 1992, the adoption of this technique has been lim-
2204
MICROROBOT ASSISTED LAPAROSCOPIC UROLOGICAL SURGERY IN CANINE MODEL
FIG. 3. Standard endoscope (A) and microrobot (B) views of renal hilum.
ited to centers equipped with significant laparoscopic skills due to inherent technical difficulties.4 Comparing current trends with a number of surgeons performing robot assisted surgeries, the overall number of minimally invasive urological procedures has increased exponentially in the last few years. The robot has allowed surgeons previously untrained in laparoscopy to provide minimally invasive procedures to patients.5 Robot assisted laparoscopic surgery lessens the learning curve for surgeons, although it is not free of inher-
ent limitations. The lack of haptic feedback remains a significant hindrance that may complicate robotic surgery.6 This study was not designed to address the impact of haptic feedback on the learning curve of laparoscopic or robotic urological procedures. Nonetheless, one can conclude that the lack of haptic feedback decreases the senses of the surgeon and perhaps lengthens the learning curve compared to conventional open surgery.6 – 8 During laparoscopic or robot assisted surgery vision limitations remain significant. The field of view cannot encompass all trocars to facilitate instrument changes, which may increase the risk of injury. Microrobots can provide a view of the entire operative field and they are not limited by the fixed port position at the abdominal wall, potentially improving procedure safety. Current robots are bulky and require significant space allocation in an already crowded operating suite. The displacement of the surgeon to an unsterile location decreases the ability or speed of the surgeon should a condition arises in which emergent conversion to the open approach is necessary. Microrobots may potentially help overcome such limitations. Microrobots also have the potential to decrease setup time compared to that of currently available robotic systems. The shortcomings of these microrobot prototypes worth mentioning include the need for a separate operator to maneuver the joystick to guide the robot to a location. The prototypes used in our experiment are tethered for power, which can be a significant hindrance. Although tether-free prototypes have been developed, these technologies are still in their infancy. These prototypes lack a self-cleaning mechanism, which is necessary due to condensation of the lenses or when they come into contact with intra-abdominal organs. The pan and tilt prototype relies on the operator to place it in a specific desired location. It is less prone to contact with moisture from intra-abdominal organs with the camera placed on top of the cylinder. The crawler prototype is capable of moving inside the abdomen using the joystick. However, its lens becomes dirty easily, given its position between the moving wheels, where it comes in direct contact with intra-abdominal contents. Without such a mechanism and further improvement in the optical system the added views provided may in some cases be of limited use compared to views provided by currently available high definition monitors or the 3-dimensional view using the da Vinci® system.
FIG. 4. Control station (A) and operating room (B)
MICROROBOT ASSISTED LAPAROSCOPIC UROLOGICAL SURGERY IN CANINE MODEL Our pilot study demonstrates that small microrobot cameras can be inserted in the abdominal cavity to assist with laparoscopic prostatectomy and nephrectomy. The value of this technology is its miniaturization format and potential to incorporate other sensors and manipulators to further aid with surgery. One or multiple robots may be used to perform specific tasks or multiple activities during a particular procedure. They may aid not only with visualization, but also with manipulation of the surgical field, eliminating the need for multiple port placement. Furthermore, they can potentially be equipped with sensors to provide feedback from the abdomen or surgical site. Only with such improved functionality will these evolving technologies perhaps make a significant contribution to our clinical surgical practice.
CONCLUSIONS Microrobot cameras provided views of the surgical field that facilitated the completion of canine prostatectomy and nephrectomy. This technology provides desired miniaturization. However, it needs further improvement and functionality to provide views of the surgical field or a range of motion comparable to that of available laparoscopic or robotic systems.
2205
REFERENCES 1.
2.
3.
4.
5.
6.
7.
8.
Rentschler M, Hadzializ A, Dumpert J, Platt S, Farritor S and Oleynikov D: In vivo robots for laparoscopic surgery. Med Meets Virtual Reality 2004; 12: 316. Oleynikov D, Rentschler M, Hadzialic A, Dumpert J, Platt SR and Farritor S: Miniature robots can assist in laparoscopic cholecystectomy. Surg Endosc 2005; 19: 473. Menon M, Shrivastava A, Tewari A, Sarle R, Hemal A, Peabody JO et al: Laparoscopic and robot assisted radical prostatectomy: establishment of a structured program and preliminary analysis of outcomes. J Urol 2002; 168: 945. Schuessler WW, Schulam PG, Clayman RV and Kavoussi LR: Laparoscopic radical prostatectomy: initial short term experience. Urology 1997; 50: 854. Ahlering TE, Skarecky DW, Lee DI and Clayman RC: Successful transfer of open surgical skills to a laparoscopic environment using a robotic interface: initial experience with the laparoscopic radical prostatectomy. J Urol 2003; 170: 1738. Tendick F, Jennings RW, Thrap J and Stark L: Sensing and manipulation problems in endoscopic surgery: experiment, analysis, and observation. Presence 1993; 2: 66. Tendick F, Jennings R, Tharp G and Stark L: Perception and manipulation problems in endoscope surgery. Computer Integrated Surg Technol Clin Appl 1996; 39: 520. Treat M: A surgeon’s perspective on the difficulties of laparoscopic surgery. Computer Integrated Surg Technol Clin Appl 1996; 41: 549.
Purpose: Robotic technologies have had a significant impact on surgery. We report what is to our knowledge the first use of microrobots to perform laparoscopic urological surgery in a canine model. Materials and Methods: Nonsurvival laparoscopic radical prostatectomy and radical nephrectomy were performed using microrobotic camera assistance. Following the administration of general anesthesia miniature camera robots were inserted in the insufflated abdomen via a 15 mm laparoscopic port. These microrobots were mobile, controlled remotely to desired locations and provided views of the abdominal cavity, assisting the laparoscopic procedures. Additional ports and laparoscopic instruments were placed in the abdomen using the views provided by these microrobots. Results: One dog underwent laparoscopic prostatectomy and another underwent laparoscopic nephrectomy. The 2 procedures were completed successfully. Microrobots provided additional views from several angles, aiding in the performance of the procedures. Conclusions: Miniature camera robots (microrobots) provide a mobile viewing platform. With added functionality these new robots have the potential to further evolve the robotic armamentarium for surgeons. Key Words: prostate, dogs, robotics, laparoscopy, prostatectomy
aparoscopy is steadily gaining ground in urology. To date there is hardly a urological procedure that has not been attempted laparoscopically in the quest by urologists to provide patients with less invasive alternatives. While some procedures are widely performed laparoscopically, others are only performed at highly specialized centers due to the difficulty associated with laparoscopic instrumentation and techniques. The advent of the robot has helped surgeons overcome some of the limitations of pure laparoscopic surgery. The robot provides a number of advantages, such as a stereoscopic 3-dimensional view of the surgical field and improved hand-to-eye coordination, allowing the surgeon enhanced dexterity in performing tasks that remain complex using pure laparoscopic techniques. While the robot has removed certain limitations of laparoscopic surgery, it has added a number of others. With the surgeon displaced from the patient bedside no haptic feedback is provided to allow the assessment of tissue consistency, which has been a major source of criticism from opponents of robotic surgery. Similar to laparoscopic surgery, the cameras used in robotic surgery rely on a fixed port system, constrained to only 4 df, potentially limiting the view.
L
Submitted for publication January 23, 2008. Study received institutional review board approval. * Correspondence: Section of Laparoscopy and Robotic Surgery, Department of Urology, University of Rochester Medical Center, 601 Elmwood Ave., Box 656, Rochester, New York 14642 (telephone: 585-341-7795; FAX: 585-756-5457; e-mail: jean_joseph@ urmc.rochester.edu).
See Editorial on page 1881.
0022-5347/08/1805-2202/0 THE JOURNAL OF UROLOGY® Copyright © 2008 by AMERICAN UROLOGICAL ASSOCIATION
The use of microrobots to assist with laparoscopic surgery has been previously reported in the general surgical literature.1 Their mobility inside the abdominal cavity provides an unparalleled view of the surgical field.1,2 We report the use of microrobot cameras to assist with laparoscopic urological surgery in a canine model. MATERIALS AND METHODS A collaborative research agreement was executed between researchers from the University of Rochester Medical Center, University of Nebraska and University College London Institute of Urology to build microrobot prototypes to assist with laparoscopic canine prostatectomy and nephrectomy. Two microrobot camera prototypes were used in this study. The pan and tilt microrobot is capable of rotation along 2 separate axes, which allows it to pan the operative field through 360 degrees and tilt upward or downward at ⫾45 degrees. Separate motors activate the pan and tilt motions. The assembled device consists of a small cylindrical tube with a diameter of 15 mm and a height of 3 inches. The lens and light source are positioned on top of the cylinder that houses the motor gears. The platform legs attached to the base are abducted by torsion springs, allowing the microrobot to stand. The prototypes were tethered with the cord exiting the abdominal cavity adjacent to the midline trocar (fig. 1). The second prototype used was the crawler (fig. 2). This prototype is also mobile. It consists of 2 cylindrical wheels capable of navigating to desired locations in the abdominal cavity. It is equipped with a lens in the middle of the cylinders, providing close-up views of the surgical site. Each type
2202
Vol. 180, 2202-2205, November 2008 Printed in U.S.A. DOI:10.1016/j.juro.2008.07.016
MICROROBOT ASSISTED LAPAROSCOPIC UROLOGICAL SURGERY IN CANINE MODEL
2203
FIG. 1. Pan and tilt prototype
of robot is tethered for power and maneuvered using a joystick. Under an institutional review board protocol 2 male dogs were anesthetized according to a standard protocol by licensed veterinarians. After induction a Veress needle was used to insufflate the abdomen using carbon dioxide up to a pressure of 12 mm Hg. A supraumbilical 15 mm midline port was used to insert the microrobot cameras inside the abdominal cavity. Only 1 microrobot was used at a time. Additional ports were placed to facilitate laparoscopic radical prostatectomy and nephrectomy. Conventional laparoscopic instruments were used to perform the procedures. RESULTS The 2 procedures were completed successfully. Miniature camera robots were used in conjunction with a standard endoscope. Video images provided by the microrobot were fed to a separate monitor. The pan and tilt camera was
placed in the abdominal cavity at desired sites using standard laparoscopic instruments for placement at specific locations. Pan and tilt functions were activated using the control joystick. The crawler was advanced to different locations remotely, also using a joystick (fig. 3). After the cameras were inserted in the abdomen they were used to view the abdominal wall, assist with proper trocar placement and eventually perform the procedure. The microrobots assisted with planning trocar positioning. They provided the surgeon with a multitude of viewing angles. The microrobots were used to assist with the completion of prostatectomy and nephrectomy. The microrobot camera views provided the surgeon with an additional frame of reference that is not available with the standard endoscope. Figure 3 shows a view of the renal hilum from the standard endoscope and a side view from the pan and tilt microrobot. Figure 4 shows the control joystick and the operating room setup. DISCUSSION
FIG. 2. Crawler prototype
Microrobot prototypes have been previously studied in inanimate and animal models.1,2 To our knowledge this study represents the first use of these devices in urological surgery. These successful prototypes are capable of providing additional views of the surgical field and they may further advance the use of robots in surgery. The pan and tilt robot provides a 360-degree view of the abdomen while the surgeon maintains a view of the surgical field through the standard laparoscope. Similar to the crawler prototype, which can be advanced to specific locations, it can provide posterior views of an organ or surgical site that are not possible via current laparoscopic or robotic cameras using a stationary viewing platform. In 2001 robot use debuted in urology.3 Groups from a number of institutions have reported large successful series incorporating this technology in various surgical procedures. Since the initial reports of laparoscopic radical prostatectomy in 1992, the adoption of this technique has been lim-
2204
MICROROBOT ASSISTED LAPAROSCOPIC UROLOGICAL SURGERY IN CANINE MODEL
FIG. 3. Standard endoscope (A) and microrobot (B) views of renal hilum.
ited to centers equipped with significant laparoscopic skills due to inherent technical difficulties.4 Comparing current trends with a number of surgeons performing robot assisted surgeries, the overall number of minimally invasive urological procedures has increased exponentially in the last few years. The robot has allowed surgeons previously untrained in laparoscopy to provide minimally invasive procedures to patients.5 Robot assisted laparoscopic surgery lessens the learning curve for surgeons, although it is not free of inher-
ent limitations. The lack of haptic feedback remains a significant hindrance that may complicate robotic surgery.6 This study was not designed to address the impact of haptic feedback on the learning curve of laparoscopic or robotic urological procedures. Nonetheless, one can conclude that the lack of haptic feedback decreases the senses of the surgeon and perhaps lengthens the learning curve compared to conventional open surgery.6 – 8 During laparoscopic or robot assisted surgery vision limitations remain significant. The field of view cannot encompass all trocars to facilitate instrument changes, which may increase the risk of injury. Microrobots can provide a view of the entire operative field and they are not limited by the fixed port position at the abdominal wall, potentially improving procedure safety. Current robots are bulky and require significant space allocation in an already crowded operating suite. The displacement of the surgeon to an unsterile location decreases the ability or speed of the surgeon should a condition arises in which emergent conversion to the open approach is necessary. Microrobots may potentially help overcome such limitations. Microrobots also have the potential to decrease setup time compared to that of currently available robotic systems. The shortcomings of these microrobot prototypes worth mentioning include the need for a separate operator to maneuver the joystick to guide the robot to a location. The prototypes used in our experiment are tethered for power, which can be a significant hindrance. Although tether-free prototypes have been developed, these technologies are still in their infancy. These prototypes lack a self-cleaning mechanism, which is necessary due to condensation of the lenses or when they come into contact with intra-abdominal organs. The pan and tilt prototype relies on the operator to place it in a specific desired location. It is less prone to contact with moisture from intra-abdominal organs with the camera placed on top of the cylinder. The crawler prototype is capable of moving inside the abdomen using the joystick. However, its lens becomes dirty easily, given its position between the moving wheels, where it comes in direct contact with intra-abdominal contents. Without such a mechanism and further improvement in the optical system the added views provided may in some cases be of limited use compared to views provided by currently available high definition monitors or the 3-dimensional view using the da Vinci® system.
FIG. 4. Control station (A) and operating room (B)
MICROROBOT ASSISTED LAPAROSCOPIC UROLOGICAL SURGERY IN CANINE MODEL Our pilot study demonstrates that small microrobot cameras can be inserted in the abdominal cavity to assist with laparoscopic prostatectomy and nephrectomy. The value of this technology is its miniaturization format and potential to incorporate other sensors and manipulators to further aid with surgery. One or multiple robots may be used to perform specific tasks or multiple activities during a particular procedure. They may aid not only with visualization, but also with manipulation of the surgical field, eliminating the need for multiple port placement. Furthermore, they can potentially be equipped with sensors to provide feedback from the abdomen or surgical site. Only with such improved functionality will these evolving technologies perhaps make a significant contribution to our clinical surgical practice.
CONCLUSIONS Microrobot cameras provided views of the surgical field that facilitated the completion of canine prostatectomy and nephrectomy. This technology provides desired miniaturization. However, it needs further improvement and functionality to provide views of the surgical field or a range of motion comparable to that of available laparoscopic or robotic systems.
2205
REFERENCES 1.
2.
3.
4.
5.
6.
7.
8.
Rentschler M, Hadzializ A, Dumpert J, Platt S, Farritor S and Oleynikov D: In vivo robots for laparoscopic surgery. Med Meets Virtual Reality 2004; 12: 316. Oleynikov D, Rentschler M, Hadzialic A, Dumpert J, Platt SR and Farritor S: Miniature robots can assist in laparoscopic cholecystectomy. Surg Endosc 2005; 19: 473. Menon M, Shrivastava A, Tewari A, Sarle R, Hemal A, Peabody JO et al: Laparoscopic and robot assisted radical prostatectomy: establishment of a structured program and preliminary analysis of outcomes. J Urol 2002; 168: 945. Schuessler WW, Schulam PG, Clayman RV and Kavoussi LR: Laparoscopic radical prostatectomy: initial short term experience. Urology 1997; 50: 854. Ahlering TE, Skarecky DW, Lee DI and Clayman RC: Successful transfer of open surgical skills to a laparoscopic environment using a robotic interface: initial experience with the laparoscopic radical prostatectomy. J Urol 2003; 170: 1738. Tendick F, Jennings RW, Thrap J and Stark L: Sensing and manipulation problems in endoscopic surgery: experiment, analysis, and observation. Presence 1993; 2: 66. Tendick F, Jennings R, Tharp G and Stark L: Perception and manipulation problems in endoscope surgery. Computer Integrated Surg Technol Clin Appl 1996; 39: 520. Treat M: A surgeon’s perspective on the difficulties of laparoscopic surgery. Computer Integrated Surg Technol Clin Appl 1996; 41: 549.