Biology 1080 - Organ Replacement

Brown University 2008

Overview

As patients demand higher qualities of care and reductions in outcome variability, there is increasing pressure for doctors to find new methods to improve surgical success. The use of computer and robotic assist devices is a rapidly growing phenomena in surgeries today, and a major contributing factor in the ever advancing techniques to optimize surgical outcomes. Surgeons using advanced machinery which produce better outcomes will receive more patients (due to reasons explained in the earlier section). One potential goal robotic surgeries is to reduce variability caused by human factors. Could we reach a point where the role of the surgeon is merely to turn a switch on and off and let a machine do the work?

In the Computer Assist Device section, we will examine navigation systems, robotic systems, and software that have had a large impact on the a number of branches of surgery.

Da Vinci Surgical System

The da Vinci Surgical System, created by Intuitive Surgical, was the first robotic surgical system approved by the FDA.  Since its inception in 2000, the da Vinci System has allowed surgeons to perform various procedures on the body through minimally invasive, 1 cm keyhole incisions.[1]

Operation

The surgeon works at a console a few feet away from the operating table.  Several controls are used while watching a magnified three-dimensional image of the surgical field on the monitor.  The “patient-side cart” refers to the robotic arms and instruments that directly contact the patient.  Anywhere from two to four instrument arms can be used along with one endoscopic arm.[2]

Applications

Cariothoracic – mitral valve prolapse, revascularization, CABG(clinical), renal tumor
removal

General – bariatric(obesity), surgery, gastric bypass

Gynecological – hysterectomy

Urological – prostatectomy

Advantages

Due to the fact that all surgeries are minimally invasive, there is a significantly lower amount of pain, blood loss, and scarring.  Recovery time is also shorter and better clinical outcomes can be acheived using the da Vinci System compared to normal laparoscopic surgery.[3]

Disadvantages

The initial capital investment, a large upfront cost, is one major deterrent of using a robotic system like da Vinci.  Also, a certain learning curve is present when surgeons use equipment like this for the first time. Thus, while robotic surgery systems attempt to reduce human factors, the "practice makes perfect" moto holds true.

Publications

Jones et al in the study titled, "Robotic Mitral Valve Repair" compared the duration of hospital stay after mitral valve repair surgery.  They compared the length of stay for their sample, who used the da Vinci System to carry out the surgery, versus results from normal laparoscopic surgery found in the 2002 Society of Thoracic Surgeons database.  Their study found a significant decrease in mean hospital stay post-surgery when using the da Vinci System (3.4 days versus 8.5 days in the 2002 database). 

http://youtube.com/watch?v=fOq78wzyIXQ&feature=related

Medtronic StealthStation

The StealthStation, a product of Medtronic Surgical Navigation Technologies, is a three-dimensional imaging system that allows surgeons to navigate through the body.  It is a next generation product that combines images from a variety of traditional sources.  Some of these include X-ray, computerized tomography(CT), magnetic resonance imaging(MRI), and ultrasound.  By combining such a variety of imaging techniques, the StealthStation allows for more precise three-dimensional images so the surgeon can focus on the exact location desired.(1)

http://www.medtronicnavigation.com/procedures/navigation/systems/treon.jsp

Operation

The StealthStation analyzes pre-operative diagnostic scans to create three-dimensional images used by the surgeon to map out the safest and least invasive surgical path.  Real time images are continually produced throughout the surgery.  By merging images from multiple sources, the StealthStation allows surgeons to view their targets from any angle.  Lastly, images of instruments are incorporated into images of the patient’s anatomy allowing the surgeon to see the exact location of the instrument in three-dimensions and in real time.(2)

Applications

Cranial Neurosurgery – tumor biopsy, tumor resection, cerebrospinal fluid management

Spinal – screw placement throughout the spine

Orthopedic Joints/Trauma – total knee replacement, total hip replacement, trauma

Ear, Nose & Throat – functional endoscopic sinus surgery, laterl and anterior skull base
surgery

Advantages

By providing advanced three-dimensional imaging the StealthStation allows surgeons to pinpoint exact locations and targets without damaging nearby tissue by offering views from normally impossible angles and by including the instrumentation in the images.  Due to the fact that surgeries are minimally invasive, pain, scarring, and recovery time are all reduced.  The wide variety of surgeries that can make use of this product is also an advantage.  Proper positioning can still be found even when the patient’s anatomy is atypical.  Specifically, when using the StealthStation in spinal surgery, the patient is subjected to a reduced amount of radiation exposure. (3)

Disadvantages

Just like the da Vinci System, the major drawbacks to using the Medtronic StealthStation are its large initial investment cost and the inherent learning curve present when surgeons must use a new system they aren’t used to.

Publications

In a study conduced by Heermann et al, it was found that three-dimensional imaging technology like the StealthStation, while not replacing the surgeons personal skill, did benefit both experienced and non-experienced surgeons.

“Navigation with the StealthStation in Skull Base Surgery: An Otolaryngological Perspective”.  Heerman et al.

An increased accuracy in placement of spinal screws while using the StealthStation was found by Vaccaro et al in their study.  They also found no evidence of spinal canal penetration (a common problem during normal surgery) when using the StealthStations three-dimentional image guidance.

“Evaluation of Image-Guided Technology in the Placement of Anterior Thoracic Vertebral Body Screws in Spinal Trauma: A Cadaver Study”.  Vaccaro et al. 

Orthopilot

History of the development of Orthopilot:

In 1994 the experimentation with kinematic navigation began.  This spurred the development of Image Guided Orthopedic Surgery (IGOS) in the European Union from 1996-1999.  1997 marked the first clinical use of IGOS, in a total knee replacement surgery.  In 1999 Orthopilot was developed and received a CE marking (stating that the product had met European standards); at this time it was introduced to the market with programming capable of performing total knee arthroplastys.  In 2001 Orthopilot received FDA approval and became the first CT-free navigation system in the U.S.  Since then there has been much development and advancements in the software used for THA, TKA, ACL reconstruction, and HTO procedures.  As of today there have been over 80,000 surgeries performed using the Orthopilot navigation system.

http://www.aesculap-extra.net/public/frame_doc_index.html?med_id=100052496

Operation

The Orthopilot system is used to provide doctors with a way to accurately execute large joint replacement/corrective surgeries.  The procedures vary depending on the type of surgery, however the general methodology of the surgery is as follows:  The surgeon fixes sensors to the part of the patient being operated on, and then moves the patient in specific natural motions so that the camera receives the data and uses it to form a model on the screen.  The representations on the monitor allow the surgeon to perform the surgery with greater accuracy, as the Orthopilot system will be able judge when the joint is properly aligned.

http://www.orthopilot.com/index.cfm?A0A5292F4830470FB75F420CE03ECC49

Applications:

Orthopilot has a number of well documented applications in the realm of large joint replacement and repair.  The most common include:

Total Knee Arthoplasty

Unicondylar Knee Arthoplasty 

Total Hip Arthoplasty

Cartilage Defect Management

Anterior Cruciate Ligament (ACL) Reconstruction

High Tibial Osteotomy (HTO)

Advantages

Prior to Orthopilot (and computer assist devices similar to it), it was not always certain that an implant would be placed in the optimal position.  With the navigation system the implant can be placed within 3 degrees of perfect position at almost every surgery.   The navigation also allows minimally invasive surgery to be performed easily because of the display, thereby increasing recovery time and decreasing post operative pain.  Also, once a surgeon becomes familiar with the navigation system, surgery time will decrease, which is an important clinical and economic factor.

http://www.aesculap-extra.net/public/frame_doc_index.html?med_id=100052496

Disadvantages

As with most computer assist devices, the major disadvantages are due to the fact that the machines are very expensive, the surgeon must undergo new training to learn how to use the device, and initially the surgeries will take much longer as the surgeon is becoming familiar with the new procedure.

Publications

In a study conducted by Tim and Hans Walde, 18 minimally invasive THA operations were performed and analyzed in comparison to a prior study of 400 minimally invasive THA’s performed manually (without using navigation).  Through these 18 patients it was observed that all of the resulting positions of the implant was superior to that of the patients who had undergone the manual implantation technique.  Overall average operation time was 10 minutes longer with navigation than with the manual implantation, however the study was fairly certain that once familiarity with the procedure was greater, time would decrease.

A study carried out by Jenny et al reviews the learning curve of the Orthopilot system.  150 total knee replacements were performed in centers that were experienced in using Orthopilot, and 218 TKR were performed in centers that were not experienced in using Orthopilot.  The results of the TKRs (the implantation accuracy, clinical outcome, and complications) from the experienced centers were as successful as those performed in the inexperienced centers; the only difference was that initially inexperienced centers needed a significantly longer time to complete the surgeries.  The increase in operating time had completely disappeared after 30 operations for a given center.   The results show that the device is effective regardless of experience.  It also shows that the number of surgeries needed to master the device is relatively low.

NeuroMate

http://www.ricercaitaliana.it/prin/dettaglio_completo_prin-2004061377.htm

Neuromate was the first robotic system designed to perform stereotactic brain surgery.
The system is currently used to aid surgeons in the execution of stereotactic neurosurgical procedures.  It was designed by Integrated Surgical Systems Inc. and was designed to performs surgeries using the VoXim™, IVS Software Engineering software system.  The image guided, computer controlled device manipulates a 6 jointed robotic arm, allowing for 5 degrees of freedom. The NeuroMate system gained FDA approval in the summer of 1999 .

http://www3.interscience.wiley.com/cgi-bin/fulltext/112653318/PDFSTART

Operation

NeuroMate can be used with the patient’s head either placed in a frame or without a frame during surgery; the difference between the two is the accuracy of the imaging displayed, with the frameless method currently less accurate but improving. The robotic and software system interact, providing a 3D view of anatomical structures of the brain using CT or MRI scans.  Once a plan is formed the surgeon will control the arm, using the imaging displayed on a PC as to guide the operation.

Applications

A wide range of neurosurgical procedures including:

Removal of brain tumors

Movement disorder surgery (for disorders such as parkinsons)

Implantation of devices to stimulate the brain (in order to alleviate the symptoms of epilepsy)

Advantages

NeuroMate’s PC based planning system was created so that it easily interfaces with other popular planning systems offered by other companies.  The machine augments surgical skill and greatly reduces fatigue, making long operations less difficult.  The accuracy of the robot also decreases operation time, especially operations involving multiple biopsies.1

Disadvantages

NeuroMate is useful in neurosurgery only, not a number of different applications like Da Vinci (and other similar products).  This device is very expensive and with very few machines being purchased, it is not economically viable for the developer/producer to continue marketing the product.   In a similar vein, neurosurgery is less common and less profitable than heart and many other surgeries, therefore it is less attractive for hospitals to spend such a large amount of money on this device.

Publications

Li et al. studied the use accuracy of NeuroMate with and without its frame components against other, more common, stereotactic surgical localization methods.  The results of this study showed that with the frame, the average error of the robot was less than a mm with the frame in place, and less than 2 mm without the frame.  These results are on par with the other methods, and had proven that the device is safe to use on humans.1

http://www.springerlink.com/content/kmcxpuylv66xu87l/fulltext.pdf

Varma and Eldridge evaluate the viability of use of NeuroMate in frameless mode in clinical study.  Patients from a variety of ailments (movement disorder, chronic pain, and epilepsy) underwent surgery using NeuroMate without a frame.  The study affirms the accuracy of the procedure, and points out an added advantage of separation of imaging from surgery.  High resolution imaging is taken one day before the surgery and using the NeuroMate system, allows time for analysis of images and trajectory planning.

1

http://www.ricercaitaliana.it/prin/dettaglio_completo_prin-2004061377.htm

http://www3.interscience.wiley.com/cgi-bin/fulltext/112653318/PDFSTART

Overall Costs

The major question facing advancements like robotic surgical products is whether or not they make procedures too expensive.  Recently, studies like the one completed by J Morgan et al have looked at this issue.  Morgan et al’s study found that, unless you include the initial investment cost, there is no significant difference in cardiac surgery cost with or without robotics.  Therefore, once hospitals got past the initial cost of purchasing products like the da Vinci Surgical System or the Medtronic StealthStation, there would not be additional costs to face.  Total hospitalization costs in the study ranged from $7,000-14,000 with robotic assistance and $4,000-11,000 without assistance, depending on the type of surgery.  OR time was found to be a major factor in the difference in cost found in the study.  This factor would probably be reduced significantly as surgeons gained more experience using robotics.  Therefore, the difference in cost, which is already found to be insignificant, will probably actually be smaller.

Concluding Remarks

While technological advancements in robotic surgery and computer assist devices are impressive and the applications vast, these technologies are expensive and require mastery by the surgeon. Given the complexity in surgical procedures and the high incidence of unexpected complications, we are still far from the day when robots reign in the operating room.

Works Cited

Citations – da Vinci

1. http://www.fda.gov/fdac/features/2002/302_bots.html
2. http://www.bmc.cardiologydomain.com/handler.cfm?event=practice,template&cpid=10083
3. http://davincisurgery.com/index.aspx?id=it&gclid=CKyC5eGRz5ICFQFjxwodHyr8IA
4. “Robotic Mitral Valve Repair”. Jones et al.  Texas Heart Institute Journal. 2005; 32(2) 143-6.

Citations – StealthStation

1. http://www.medtronicnavigation.com/procedures/navigation/systems/treon.jsp
2. http://wwwp.medtronic.com/Newsroom/LinkedItemDetails.do?itemId=1101832866677&itemType=fact_sheet&lang=en_US
3. http://www.medtronic.com/physician/navigation/index.html