REVO

The 14th Asan Medical Center Robotic Surgery Symposium (Feb. 3, 2024)

Robot-assisted Radical Prostatectomy Using the Revo-i System (Korea Cancer Center Hospital, Director of Robotic Surgery Center, Dr. Kang Hyon Song)

Through this event, the surgical performance of domestic surgical robotic system Revo-i will be more widely shared. Today's presentation consists of an introduction to the Revo-i surgical robotic system and a description of the surgical image of radical prostatectomy using Revo-i.

Introduction to the Revo-i Surgical Robotic System

Trends in prostatectomy continue to change. In the past, open surgery was the mainstay, but laparoscopic surgery, a minimally invasive surgery, has become the general trend. While laparoscopic surgery has many advantages, it also has the disadvantage of being difficult and requiring high-level skill. Robotic surgery has emerged to overcome this disadvantage. Robotic surgery has recently become the mainstream due to its many advantages that allow surgeons to focus on the surgery.

As of 2023, there are about 8,500 surgical robotic systems installed worldwide. In terms of global distribution, the United States has the highest supply, followed by Europe. The Asian market is also growing, particularly in Japan, where the expansion of reimbursement is further increasing the number of surgical robotics installations.

Until now, there has been only one option in the market. However, the self-developed Revo-i surgical robotic system from meerecompany in South Korea is now emerging as a new alternative. The Revo-i system consists of a master console, an operation cart, and a vision cart.

Meanwhile, from the perspective of technology development, the differences and functions of surgical robotics can be examined based on four classifications: user interface, robotic cart type, remote center of motion (RCM) operating principle, and console type.

First, the user interface deals with how to operate the robotic system, including whether or not to use pedals and how to operate the controller. The master console of Revo-i is equipped with finger grippers and pedals. However, there are also products that do not have pedals or use joysticks or grasping handles.

Second is the robotic cart type, which can be categorized into standalone-type models, where multiple robotic arms are combined into a single unit, and modular-type models, where there are multiple and separate robotic arms. The familiar equipment that has been used in the past is the standalone model, and the robotic cart of Revo-i, the operation cart, is also a standalone model. On the other hand, the modular model is a new model that has recently appeared in the market. However, this modular model is known to take up a large amount of space. It makes the operating room feel cramped, and it is cumbersome to put a drape on each robotic arm.

Third is the remote center of motion (RCM) operating principle. RCM is a point that maintains stability by allowing the rotation axis to rotate around a center point. Stability must be maintained so that the robotic arms can operate safely in the abdominal cavity without shaking, thus preventing unexpected injuries. In RCM, there are mechanical RCM and software RCM. Software RCM allows for simplicity in using the robotic arm itself as it rotates around virtual points via software, but there is a risk of unexpected situations involving malfunction in the software. Revo-i adopts a more reliable mechanical RCM.

Finally, there are the conventional closed console and open console for the console type. An open console usually requires a separate pair of 3D glasses to be worn. The master console of Revo-i is a closed console.

To summarize, the Revo-i surgical robotic system has a closed console for the master console and finger gripper and pedals for the user interface side. The operation cart is a standalone-type model, and the RCM operating principle is mechanical RCM. 

Next, take a look at the performance of Revo-i to date. Revo-i began development in 2007 and went through four versions of prototypes before it was released to the market in 2018. It has been used full-scale in specialized surgical and maternity hospitals since then and was introduced in the Korea Cancer Center Hospital in late 2021. It was first exported to Uzbekistan in 2022 and was introduced to Severance Hospital in 2023.

Revo-i is a competitively priced system. The disadvantage of robotic surgery is its high cost. This cost includes not only the cost of the surgical robotic system itself but also service and maintenance, as well as instruments and accessories during operation. Therefore, it is important to consider not only the cost of the introduction but also the cost of maintenance and consumables when introducing a surgical robotic system. Revo-i shows cost savings of about 40% compared to other surgical robotic systems when all the costs are considered. 

The indications for surgery with Revo-i have also been expanding. At the time of its initial launch in 2018, it was only available for a few surgeries that had been performed in clinical trials. Since then, the scope has been expanded to include surgical surgeries in 2019 and gynecological surgeries in 2020. In addition, there were few cases of applying high-difficulty cancer surgeries that could maximize the advantages of robotic surgery before. Since its introduction to the Korea Cancer Center Hospital, however, it has been actively used in high-difficulty cancer surgeries, mainly in urology and other departments. Currently, most surgeries that can be performed by laparoscopy or robotic surgery are performed with Revo-i in the Korea Cancer Center Hospital. 

As of the end of 2023, the cumulative number of Revo-i surgeries was reported to have reached about 1,200 cases overall. For these 1,200 cases, the surgeries were performed well without any major problems, so further accumulation of clinical cases is expected to strengthen confidence in the safety and usefulness of Revo-i. 

Radical Prostatectomy Using Revo-i

The imaging case for the surgery was a patient, a 73-year-old man with elevated PSA of 5.8 ng/mL, and the biopsy results were positive in 3 of 12 sites. The tumor was a left-sided with a Gleason score of 6 and PI-RADS classification of 3 from the MRI. In discussing treatment methods with the patient after diagnosis, it was decided to perform robotic prostatectomy using Revo-i because the patient wanted aggressive treatment.

The prostatectomy is performed by a transperitoneal approach. The A arm is using the Bipolar Maryland Forceps, and the B arm is using the Monopolar Curved Scissors. The D arm is equipped with and uses Atraumatic Fenestrated Forceps.

When I started the robotic surgery, it was difficult to perform bladder neck dissection, but now I am performing it without any problems. When bladder neck dissection is performed, it has been done with bladder neck sparing. This is because it makes anastomosis easier and helps the patient self voiding. The camera setting is basically configured to perform the surgery with a 30-degree down camera view. The camera setting is typically set to a 30-degree down view for surgery, but in specific cases, it is changed to a 30-degree up view for the procedure.

Compared to when I first started performing robotic surgery, the techniques have evolved. Initially, it was performed by opening the endopelvic fascia as when performing open surgery. Recently, however, it has been performed in a way that preserves the endopelvic fascia without cutting it. It is more difficult to preserve the endopelvic fascia, but doing so is expected to help the patient self voiding. Moreover, the procedure was initially done by ligating the dorsal venous complex first and then resecting the prostate. This has changed recently, and it is done by resecting the prostate first and then treating the dorsal venous complex.

After resecting the prostate, frozen biopsy must already be in progress. In the initial surgery, there were some problematic areas on the apical margin, so frozen biopsy is now being performed.

After the anastomosis, the surgery is completed by making sure that the anastomosis area is not leaking. In addition, the sutures are not knotted after suturing but closed with clips. At the 4-week follow-up after surgery, the patient recovered well without any major problems.

Take Home Message

There used to be only one choice for surgical robotic devices, but nowadays, Revo-i could be regarded as another option. Currently, the number of Revo-i surgery cases is increasing, and the outcomes are reported to be excellent. The effectiveness and safety of Revo-i are expected to be secured even further in the future. Following its introduction to the Korea Cancer Center Hospital, the number of cases has expanded significantly, especially for high-risk cancer surgeries. Revo-i is now being actively utilized for major surgeries, demonstrating good results that are not much different from surgeries using conventional robotic surgery systems.

The quick feedback and improvement process is a great strength of Revo-i. Through collaboration with engineers from the Korea Cancer Center Hospital and meerecompany, the performance of hardware systems, software systems, and instruments has further improved.

Another great strength of Revo-i is that it has a competitive price compared to other surgical robot systems. In Korea, more than 80% of prostatectomies are done via robotic surgery. Due to the nature of the Korea Cancer Center Hospital as a public medical institution, however, more than 50% of prostatectomies are still done via open surgeries. Nonetheless, by utilizing the cost-effective aspect of Revo-i, robotic surgery—a more effective, safer surgical method—is expected to be provided to many patients at a lower cost. In terms of system maintenance, Revo-i is also cheaper than other surgical robot systems. It is expected to be economical in regard to hospital operation, even if there are few robotic surgery cases. 

Q&As

Q: Since meerecompany, the maker of Revo-i, is a domestic company, smooth communication and feedback were introduced as a strength. After the feedback given, is the response to the feedback quick and are technical improvements realized? 

A: Yes, generally, providing feedback after use leads to improvement. However, there have been cases where meerecompany has proactively identified areas for improvement and made enhancements themselves.