Urology
Introduction
The long term economic advantage, increased accuracy, and improved quality demonstrated by industrial robots have encouraged urological surgery to embrace the usage of robotics for health care delivery since the late 1980’s. 1,2 At first, Guy’s hospital and Imperial College London collaborated together. The first urological robot, also known as URobot was the PROBOT in 1989 which was used in clinical trials for transurethral resection of the prostate (TURP).4 In 1994, Potamianos looked into a robotic system to assist in intraoperative percutaneous renal access. They used a passive, encoded arm equipped with electromagnetic brakes, mounted onto the operating table. The access needle was positioned by hand as prescribed by the computer, which formed the calyx location from multiple C-arm X-rays. Later, in vitro experiments that evaluated the system performance showed a targeting accuracy of less than 1.5 mm. In 1995, the RCM (Remote Center of Motion), which was developed by a research group led by Russell Taylor, was added to the LARS robot. RCM is now a part of nearly all medical robotic systems. Additionally, minimal invasive surgery using robots in laparoscopy, a procedure enabling surgeons to directly view the organs of the abdomen and pelvis, have been successfully applied. AESOP (Automated Endoscopic System for Optimal Positioning) was one of the first to control laparoscopic tools in urologic surgery with its manipulator arms. Laparoscopic systems are fairly new developments have recently been cleared by the FDA.4 Although, robot assisted surgery is fairly new and even more recent in urologic surgery, the technology has overall proven beneficial and will continue to develop further.
Robots are or will assist urologists with transurethral resection of the prostate, percutaneous renal access, laparoscopy, and bracytherapy2. Robots are of major interest as surgical tools due to their ability to operate on a patient with an automatized gesture that is more accurate, more reproducible for each patient, and related to the specific anatomy of the patient and to the specific disease3.
Robotic devices that assist in surgery are always under human control and function as a master and slave. Davies B from “A Review of Robotics in Surgery” states that a surgical robot is “a powered computed-controlled manipulator with artificial sensing that can be reprogrammed to move and position tools to carry out a range of surgical tasks.” The goal of the robots are to facilitate and improve the techniques and procedures of urological surgery3.
Science & Technique
Robots are enslaved devices that are under the control of the surgeon. Surgical robots capture the skills of the surgeon and adds their own advantages to improve the surgery. One of the most important component of the surgical robot is the manipulator, electro-mechanical arms that are usually equipped with sensors and actuators that hold and precisely move the surgical instrument through the computer via the surgeon. The manipulator uses the RCM mechanism to enable the pivoting motion of instruments about a certain point in space which is usually located on the instrument itself. RCM aids minimally invasive tools to enter the same entry point consistently. All commercially available surgical robots are RCM based robots4. The image acquisition device is another important part of the system. This is any medical imaging device such as MRI, x-ray, and video. However, imaging compatibility is a concern. Minimally invasive surgery usually uses intraoperative video to provide a view of an area. 3D visualization of the surgical field increases surgical performance. However, many of the newer technologies for 3D imaging are large, expensive, and difficult to use. Hopefully in the future great imaging technology such as HD will become standard operating room technology4. Another component of the surgical robot system is the computer which is the link between the medical images, sensors, and databases, to the physical action of surgery. The computer also holds a lot of information about the intervention itself and what was applied for each intervention4.
The application of surgical robotics are based on preoperative data or the surgery progresses in the operating room. They can be divided in two broad groups of Image-Guided and Surgeon-Driven systems4.
Image-Guided robotic systems are able to reach a target specified by the surgeon. For example, in percutaneous needle access, these systems guide and sometimes insert the needle, instrument, or probe so that it is correctly aligned. These systems take advantage of their capability to register medical images to the patient more easily and precisely than humans can. These allow the surgeons to pinpoint on a medical image of the location in which (s)he would like to place a tool after approval4.
Surgeon-Driven systems continuously take the surgeon’s inputs and in real time translate it to appropriate instrument manipulation. The robots augment the manipulation capabilities of the surgeon that decrease tremor, scale motion, and aid in manipulation of tissues in confined spaces and also have the potential to provide remote tactile and force feedback. Surgeon-Driven systems decrease the invasiveness of some of these operations.4.
The different types of surgery listed below are only some of the applications of robot with urologic surgery.
i. Laparoscopic Surgery
Laparoscopy surgery is an operation in which a laparoscope, a lighted viewing tube, is inserted through tiny incisions for examination of internal organs directly or surgery. It is also known as keyhole surgery. Medically it refers to procedures done within the abdomen or pelvic cavity. Equipment involved when proceeding with laparoscopy are veres needle, gas insufflators, laparoscope, and light source. Laparoscopy can be used to establish the cause of fluids in the abdomen, examine and biopsy the liver, determine the stage of cancer of an abdominal organ, remove the gallbladder, and remove all or parts of the prostate and kidney. Generally speaking, laparoscopy will take 30 minutes or more depending on treatment. Results are usually ready within 24 to 48 hours. General risks are injury or perforation of bowels, liver, spleen, ovary, gallbladder; bleeding, infection, rupture of aorta, pain in the abdomen and the shoulder. It is minimally invasive and makes it possible to perform a biopsy without major, open surgery11.
An advantage of open surgery as compared to laparoscopy is that the operator knows even without seeing where his hands are because he is able to feel his way through. But with 3D vision of laparoscopic devices, the surgeon has a way of knowing where the respective position of all instruments and their location in relation to the anatomical structures3. There are other definite data supporting the advantages of laparoscopy surgery of different types to that of open surgery. Clinical studies have shown that the incidence of pulmonary complications is lower in laparoscopy. Long-term results of laparoscopic Nissen fundoplication are camparable with open surgery with incidence of failure being 6.6% but with advantages such as less bleeding, no intestinal obstruction, no evisceration5. Even positive surgical margins are similar between expert open and laparoscopic surgeons of 12.8% and 13.7%1. The complexity and technical demands of laparoscopic urologic surgery as well as the low volumes of cases compared to other forms of surgery such as cardiac surgery has made it difficult for surgeons to progress beyond the steep learning curve6. However, with increasing experience, skill, and improved instrumentation, laparoscopy is being well adapted, moving further along in urological surgery and robots are assisting in the progress.
As laparoscopic surgery became more popular, there has been a development of devices to assist the surgeon. These early devices consist of a manipulator arm that positions the laparoscopic instruments. These arms help reduce distractions by eliminating inadvertent and disorienting movements of a human assistant. But, they require the surgeon to release the surgical instruments to reposition the laparoscope. Eventually other robots were developed that actively moved the laparoscope and allowed the surgeon to keep his/her hands on the surgical instruments. LARS robot a 7 degree of freedom (DOF) device was clinically successful but was limited by safety concerns. The first robot to receive FDA approval was AESOP with 6 DOF. In a study, use of AESOP to hold camera during laparoscopy is more steadier and effective than their human counterpart6. It is not proven, but robotic surgical assistants may be more economical than human assistants for laparoscopic surgery7. Further development is underway to improve dexterity and provide force feedback to the surgeon.
There is not enough studies and trials that clearly demonstrate that robotic laparoscopic surgery is better than laparoscopic surgery. However in various cases there are substantial information supporting robotics. Laparoscopic radical prostatectomy is a well established surgical procedure for the treatment of organ-confined prostate cancer. But, LPR has a long learning curve of at least 40 cases to achieve an acceptable operative time and complication rate. Robotic-assisted laparoscopic radical prostatectomy can offer a more ergonomic environment and can significantly shorten the learning curve. As in one case, as stated by Dr. Wagner in the interview, for him the learning curve for robotic urologic surgery is 20-30 cases before he was fairly comfortable. Although, a study in Detroit states that positive margins were more frequent for ORP 23% as to 9% for robotic surgery, and the robot has its disadvantages of lack of touch sensation, hand to eye dissociation, and the cost factor (which for the da Vinci machine is $1.5 million), there are definitely benefits. It provides dexterity enhancement and motion scaling, and emerge in situations when careful dissection or reconstruction is needed8. Although In a personal experience of 60 cases as mentioned in “Laparoscopy, robot, telesurgery, and urology: future perspective,” RAP may have marginally taken longer than open surgery but there were less blood loss, less pain, less analgesia, and shorter hospital stay6. A Detroit team reported that after their unrandomized comparison of 200 robotic RP’s with 100 open radical prostatectomy (ORP), operating time was about the same and that none of the patients after robotic RP needed a blood transfusion. Hospital stay was 1.2 days for robotic, 1.3 days for LRP, and 3.5 days for ORP. The respective catheter duration was 7, 8, and 15 days1. As a speculation, these new systems can intentionally increase the number of conventionally trained surgeons to do more complex procedures using minimally invasive surgery.
Laparoscopic nephropexy, pyeloplasty, and ileocystoplasty have been observed with robots. Some of the cases using da Vinci had a longer operative time than conventional laparoscopy for a particular urologic surgery while other showed a shorter operative time, and reconstruction time. ( The robots advantage over conventional laparoscopy is minimal. Cost is also factor in the usage of robot in more complex procedures such as ileocystoplasty and pyeloplasty. But the overall reduction in operating time will probably make up for the increased cost of robotic surgery. Additionally, the da Vinci may decrease the difficulty of laparoscopic reconstructive surgery which then increases clinical applicability.
A type of procedure that robotic laparoscopy surgery is under investigation for is partial nephrectomy. A study was done between Nov. 2002 and Aug. 2003 amongst 13 patients to develop and assess the feasibility of laparoscopic partial nephrectomy using the da Vinci system. The results showed an average operative time of 3.8 hours, and a mean blood loss of 170 mL. Average warm ischemia time was 22 minutes. However, 8 patients had a perioperative arterial catheter placed for intrarenal cooling. Robotic-assisted partial nephrectomy using a transperitoneal and retroperitoneal approach is feasible9. However, retroperitoneal approach with the robot is difficult. It remains to be seen if robots assist or take over in this particular procedure.
ii. Telesurgery, Telemedicine, Telementoring
Remote controlled instrumentation and Munich operating room in telesurgery case (http://pegasus.me.jhu.edu/~rwebster/index_files/pub_files/chapter.pdf)
Telesurgery is an integration of multimedia, telecommunications and robotic technologies that provide surgery at a distance6. Telesurgery in urology is being evaluated with more advances in technology7. Telemedicine is the exchange of real time data of medical information between physicians in different locations. Telementoring is the assistance of an experienced surgeon in a remote operation4. An experienced surgeon at a remote site can teleoperate the robotic arm and guide the primary surgeon through a procedure. This would be an education device to convey the expertise and experience of a an adept surgeon to second surgeon at a different location. The system as of 1999 incorporates bidirectional video and audio communication, telestration, electroautery remote activation to stop blood vessels from bleeding, x-ray image transfer and remote control of AESOP robot.7.
For laparoscopic procedures in particular there have been three generations of laparoscopic telesurgery. The first operated remotely within the same hospital. The second moved the remote site to a different institution of about 3.5 miles away. The third generation involved laparoscopic telesurgery in an international level in which pr ocedures were done in Thailand, Austria, Italy, and Singapore. Telementoring used for an education purpose was done between Singapore and the United States.7.
Developments in telecommunications and computer technology is improving and developing the application of telesurgical, telemedicinal, and telementoring devices.
iii. Percutaneous Renal Access
Percutaneous renal access is through the skin renal access. A large part of this procedure is based on the surgeon’s experience and technique. There have been several robotic systems to assist the urologist with intraoperative percutaneous renal access. The Imperial College of London developed a passive 5 DOF manipulator. Johns Hopkins Medical Institutions developed an active robot to manipulate the access needle and a biplanar fluoroscopic imaging system. At first problems arose with these robotic devices. There was kidney displacement by needle insertion, needle deflection or bowing, and rib inference. But this system showed that a fully automated robotic system for soft tissue needle placement is very feasible. A new device names PAKY was developed in 1996 that mimics the urologist’s manual procedure yet increases speed, accuracy, and safety. Surgical trials using PAKY show a success of percutaneous access in 9 out of 10 patients. There was a mean time to gain access of 16 mins in the successful cases. Another robotic device used in this surgical procedure is RCM (Remote Center of Motion) that has an extremely low profile, hence, making it compatible with portable x-ray units an computed tomography scanners.7.
Training
Training for any type of surgery is essential and beneficial. Training especially for laparoscopic procedures would help to decrease the extremely long and steep learning curve for laparoscopy. Laparoscopy can be efficiently trained and tested using robotic devices under different situations. In 2002, a 3-step laparoscopy training system using a robotic device at URobtics laboratory in Maryland is near completion to train surgeons. An ideal laparoscopy training technique would be using virtual reality (VR)4. VR simulators would allow the surgeon to plan the surgical procedures prior to any incision being made. This systems would decrease risk to patient and improve the experience of the surgeon. Urologic simulators exist has existed prior to 1999 at HT Medical, Inc (Rockville, MD). They have developed a VR flexible ureteroscope simulator to navigate through the collecting system and identify tumors and stones7. Dr. Manyak’s research group at George Washington University uses the Visible Human dataset for generating surface based geometric data. Their VR trainer provide a realistic experience of the lower urinary tract in endoscopic procedures. The group has and continues to develop a computer-based surgical simulator that incorporates a surgical tool interface with anatomic detail and haptic feedback4.
VR training helps the accuracy and efficiency of surgeons.
Complications
A complication that can occur with robotic surgery is that the robot can breakdown in the middle of the surgery which will cause the surgeon to rely on conventional surgery. Other complications that can occur are not caused by the robot because it is a “master and slave device.” It will be due to the surgeon or any other risks or problems that might occur with any surgery whether it is conventional or with a robot.
Comparison
Based on the British Journal of Urology in 2003, these are the current statistics for robotic surgery for prostate cancer as compared to already existing techniques.
Compared to other types of minimally invasive surgery, da Vinci system offers the surgeon an increased range of motion, improved dexterity, enhanced 3-D views and improved access of the surgical site. The robotic system provides very accurate, less invasive, nerve-sparing surgery. For patients, this means fewer complications, less blood loss, less scarring and faster recovery and return to normal daily activities. Research documents how effective the computeraided surgery is:
| Variable | Open surgery | Laparoscopic | da Vinci® |
| Number of cases | 100 | 50 | 100 |
| Average blood loss, millimeters | 900 | 380 | <100 |
| Cases with complications | 15 | 10 | 5 |
| Average days with catheter afterwards | 15 | 8 | 7 |
| Average days hospitalized | 3.5 | 1.3 | 1.2 |
|
TABLE 1 Comparison of retropubic, laparoscopic, robotic, and perineal prostatectomy | ||||
| RRP | Laparoscopic | RRLP | RPP | |
| Patients (No.) | 100 | 50 | 100 | 50 |
| Operative time (min) | 164 | 248 | 140 | 150 |
| EBL (mL) | 900 | 380 | <100 | 500 |
| Margin positive (%) | 24 | 24 | 5 | 10 |
| Complications (%) | 15 | 1 | 5 | 2 |
| Length of catheterization (days) | 15 | 8 | 7 | 10 |
| Hospital stay (days) | 3.5 | 1.3 | 1.2 | 1.5 |
| 5-year biochemical recurrence-free survival (%) | NR | NR | NR | 90 |
| EBL = estimated blood loss; NR = not reported. Adapted from Menon M.20 | ||||
| TABLE 1 Comparison of RRP and VIP: A single institution experience | |||
| RRP (n = 100) | VIP (n = 200) | P Value | |
| Oncologic control | |||
| Undetectable PSA (%) | 85 | 92 | NS |
| Positive node status (%) | 2 | 1 | NS |
| Positive margins in organ-confined cancers, PT2a-T3a (%) | 23 | 9* | <0.05 |
| Postoperative pain | |||
| Mean score (range) | 7 (4–10) | 3 (1–7) | <0.05 |
| Inconvenience | |||
| Mean hospitalization, days (range) | 3.5 (3–6) | 1.2 (<1–5) | <0.05 |
| Discharged within 24 hr (%) | 0 | 93 | <0.001 |
| Mean catheterization time, days (range) | 15.8 (7–28) | 7 (1–18) | <0.05 |
| Complications | |||
| Procedure aborted, no. (%) | 1 (1) | 2 (1) | |
| Procedure converted, no. (%) | NA | 0 | NS |
| Rectal injuries, no. (%) | 1 (1) | 0 | NS |
| Postoperative ileus, no. (%) | 3 (3) | 3 (1.5) | NS |
| Wound dehiscence/hernia, no. (%) | 1 (1) | 2 (1.5) | NS |
| Postoperative fever/pneumonia, no. (%) | 4 (4) | 0 | <0.05 |
| Lymphocele, no. (%) | 2 (2) | 0 | NS |
| Obturator neuropathy, no. (%) | 2 (2) | 0 | NS |
| DVT, no. (%) | 1 (1) | 1 (0.5) | NS |
| Postoperative MI, no. (%) | 1 (1) | 0 | |
| Postoperative bleeding/re-exploration | 4 (4) | 1 (0.5) | NS |
| Total complications (%) | 20 | 5 | <0.05 |
| Intraoperative parameters | |||
| Operative time (min) | 163 (86–395) | 160 (71–315) | NS |
| EBL, mL (range) | 910 (200–5,000) | 153 (25–750) | <0.001 |
| Intraoperative transfusion required | Autologous: 56 Banked: 11 | Autologous: 0 Banked: 0 | <0.001 |
| Total transfusions | 67 | <0.001 | |
| *Margin status is based on intraoperative periapical biopsies. RRP = radical retropubic prostatectomy; VIP = Vattikuti Institute prostatectomy; PSA = prostate-specific antigen DVT = deep venous thrombosis; MI = myocardial infarction; EBL = estimated blood loss; NA = not applicable; NS = not significant. | |||
Cost
The da Vinci System costs 1.2 million dollars and has a maintenance fee of $100,000 per year after the first year. Also, the average cost of disposables is $1,500 per patient. Furthermore, the learning curve is extremely high, and the da Vinci system is not widely available.
However it appears as though robotic systems do not significantly increase hospital costs for cardiac surgery. One can assume the same for urologic surgery also because, urologic surgery, especially prostatectomy, are the best examples of the improvements of robotic assisted surgery. While the absolute cost for robotic assisted surgery are higher than conventional techniques after taking into account the institutional cost of the robot; the major driver of cost for robotic procedures will likely continue to decrease, as the surgeons becomes increasingly familiar with the system. Plus, other benefits, such as improvement in postoperative quality of life and more expeditious return to work, may make a robotic approach cost effective. Thus it is probable that the benefits of robotic surgery may justify investment in this technology11.
As for the patients, there are no additional costs for robotic assisted surgery since it is part of the trial period. Standard charges for prostate surgery in particular, range from $3000 for subsidized patients to $11,000 for foreigners. But once the research period is over, it may cost about $3000 more per patient12.
Future
Enhanced safety, sterilization, compactness, operating room requirements, compatibility with medical equipment, and special ergonomics, and inexpensive material is required for the development of new technology in the field of urobotics. Additionally, the soft-tissue of most urologic operations, limits the robotics used because they need to adapt to the deformability and mobility of the operated organ. However, many researches are being done to further develop this recent but helpful techonology in urologic surgery.
URobotics (Urology Robotics) is a program of the Urology Dept. at Johns Hopkins Medical Institutions dedicated to researching and developing new technology for urologic surgery (http://urology.jhu.edu/urobotics)