Robotics in rectal cancer: Advantages for surgeons or for patients?

Abstract

Although robotic surgery has been implemented for 2 decades, evidence is limited regarding its clinical and economic benefits compared to traditional laparoscopic approaches. Studies like ROLARR have shown no significant differences, often due to biases related to the surgeons’ experience.

The treatment of rectal cancer is complex, and robotic surgery promises to facilitate embryological dissection, potentially improving oncological and functional outcomes. However, solid evidence is still scarce. The advantages of robotic surgery for surgeons include better ergonomics, precision in movements, and the possible connectivity between systems for telemonitoring. Despite current limitations, robotic surgery offers promising future prospects for both patients and surgeons.

Resumen

A pesar de dos décadas de implementación, la evidencia sobre los beneficios clínicos y económicos de la cirugía robótica en comparación con enfoques laparoscópicos tradicionales es limitada. Los estudios, como ROLARR, no han mostrado diferencias significativas, a menudo debido a sesgos en la experiencia de los cirujanos.

El tratamiento del cáncer de recto es complejo, y la cirugía robótica promete facilitar la disección embriológica, potencialmente mejorando resultados oncológicos y funcionales. Sin embargo, la evidencia sólida aún es escasa. Entre las ventajas para los cirujanos se incluyen una mejor visión, mejor ergonomía, precisión en los movimientos y la posibilidad de conectividad para la telementorización. A pesar de las limitaciones actuales, la cirugía robótica ofrece perspectivas prometedoras tanto para pacientes como para cirujanos en el futuro.

Introduction

Since the beginning of this decade, we have seen a significant increase in the number of surgical robots installed in Europe, which has been in part the result of growing interest in their application for the treatment of rectal cancer. Despite this, there have been many impediments to the implementation of this technology over the last 2 decades.

More than 2 decades have passed since the first robotic surgical procedure was performed in colorectal surgery. Since then, many of us have witnessed or participated in discussions regarding the potential clinical benefits of robotic colorectal surgery, as well as its cost-benefit ratio.^1,2

There have been constant comparisons with the laparoscopic approach or transanal total mesorectal excision (TaTME) for the surgical treatment of rectal cancer. Both randomized and non-randomized prospective studies have been conducted and published, frequently reporting no differences between these approaches, although many of these studies presented patient selection biases.³

It is important to remember the significant initial cost of this technology 2 decades ago, as well as the difficult access to these devices for the vast majority of patients and surgeons. At the end of 2010, there were just over a dozen robotic systems installed in Spain and Portugal, several of which were located at a single institution. In addition to the limited number of systems available, the competition for access to the robotic systems among various surgical specialties (Urology, Gynecology, General Surgery, and their subspecialties, etc) made access even more complicated. The current situation is starting to change somewhat, due in part to the commercialization of new and different robotic platforms, as well as the expiration of certain DaVinci system patents (Intuitive Surgical, Sunnyvale, CA). This new context may improve access to robotic surgery for a growing number of surgeons and patients, leading to the expansion of robotic surgery in our setting.

Until now, this lack of access has undoubtedly limited the ability to conduct high-quality prospective studies with surgeons who are experts in several different approaches. Meanwhile, the surgical teams at certain hospitals became heavily invested in robotic surgery and have not continued to gain experience in the laparoscopic approach or TaTME. Similarly, medical centers that either lacked access to robotic surgery or had not made the investment in this technology were unable to gain experience in robotic techniques and continued to use either the aforementioned approaches or open surgery. For many years, the end result of this situation was a small subgroup of hospitals with limited initial experience in robotics or TaTME for the treatment of rectal cancer versus a large majority of surgical teams with greater experience in laparoscopic surgery. A good example of how this translated into prospective randomized studies was ROLARR, a prospective, multicenter, randomized study that compared the laparoscopic and robotic approaches for the treatment of rectal cancer.⁴

The results of that study showed no significant differences between the 2 approaches, but were biased by experience: the subgroups of surgeons participating in the laparoscopic versus robotic arms of the study represented 1000 versus 100 previous cases, respectively. This bias was demonstrated in a subsequent publication by the same group of authors, which controlled for experience bias and found significant differences between the different approaches in favor of robotic surgery.⁵

However, more recent publications, including the prospective multicenter RESET study, have not been able to reproduce these differences.³

New robotic platforms

In recent years, several new robotic platforms have appeared on the market, many offering access to the technology at a somewhat lower cost and with differentiating technical features. For instance, the fundamental difference between platforms like the Hugo RAS (Medtronic, Minneapolis, MN) or Versius (CMR, Cambridge, UK) and the DaVinci X or Xi multiport systems (Intuitive Surgical, Sunnyvale, CA) are: (1) the open console, with potential benefits for surgeons-in-training as there is no need for a second console; or (2) the architecture based on independent arms that are potentially advantageous when working from different angles in the abdomen. Other systems, such as Hinotori (Medicaroid, Kobe, Japan) or Toumai (Medbot, Shanghai, China), have more similarities with the DaVinci multiport systems from an architectural point of view, incorporating functionalities such as haptic feedback (“Force Sensing”) or telesurgery systems using 5 G networks.

Lastly, we would like to highlight the recent launch of single-port systems, such as the DaVinci SP (Intuitive Surgical, Sunnivale, CA), which enables the surgeon to perform robot-assisted surgery with 3 instruments and flexible optics through an incision measuring less than 3 cm. Although the clinical benefits are still being explored, the initial experiences with transanal^6,7 and transabdominal colorectal surgery⁸ have already been published.

Treatment of rectal cancer

The surgical treatment of rectal cancer has traditionally been considered one of the most complex in our specialty. From the initial surgical approaches in the treatment of rectal cancer by Ernest Miles, Paul Kraske and Henri Hartmann to the present day, we have gone through phases in which performing a colorectal anastomosis was not considered the preferred option, doubts arose regarding the anterior or posterior approach as the approach of choice, and debates were had regarding the appropriateness of the minimally invasive approach.

While it is true that we are experiencing a boom in organ-preserving strategies due to the increased use of chemoradiotherapy and immunotherapy, the standard treatment for more than half of patients with rectal cancer is still total mesorectal excision (TME) with colorectal anastomosis, either with or without a temporary stoma.

This surgical technique is considered complex due to the anatomical location of the rectum, surrounded by nervous, vascular, and urinary structures in a space delimited by the pelvic bones. This becomes even more complex in cases where the patient has a high body mass index (BMI), a large prostate, or a large fibroid uterus.

Even more technically complex are cases of local recurrence of rectal cancer, which often require multivisceral resections, especially if the intention is to perform a minimally invasive approach.⁹

Robotic surgery in the treatment of rectal cancer

The application of robotic surgery for the treatment of rectal cancer has evolved significantly in recent years. The idea for its implementation probably stems from initial experiences in the field of Urology,¹⁰ where the benefits of this technology in the treatment of prostate cancer became clear from the outset. The ability to work in spaces distant from the point of access, inherent to laparoscopy, or the ability to work in confined spaces afforded to the surgeon by the robotic platform, led to the consideration of its use in the field of colorectal surgery, especially in rectal cancer. It is also important to remember that the implementation of laparoscopic surgery in the treatment of rectal cancer has always been more technically demanding and lagged behind its implementation in the treatment of colon cancer. This is probably why TaTME was on the rise for over a decade and proposed as the technique of choice over laparoscopic anterior resection, arguing that it offers better access, vision, and work capacity, in exchange for requiring learning from the transanal perspective and how to recognize anatomical structures.

Advantages of robotic surgery for patients

As with prostatectomy, robotic surgery for the treatment of rectal cancer has potential benefits, such as facilitating embryological dissection, avoiding nerve injury in the area of the hypogastric plexus, both superior and inferior, and secondarily improving genitourinary and defecatory function results. Furthermore, this embryological dissection can facilitate obtaining clear margins and a complete mesorectum, thereby minimizing local recurrence in locally advanced tumors treated with chemoradiotherapy. In cases where the cancer is located in the distal third of the rectum, the robotic approach, thanks to the stability of the camera and the articulated instruments, can facilitate intersphincteric dissection by combining both transanal and transabdominal approaches.^11,12

At the moment, there is no strong scientific evidence to support all of these potential benefits, as the REAL randomized multicenter study is the only one that supports any of these claims regarding benefits in the postoperative period. This study found that, for mid- and lower rectal cancer, robotic surgery provided better oncological quality of resection than conventional laparoscopic surgery, with less surgical trauma and better postoperative recovery.¹³

Other studies, such as the previously mentioned ROLARR^4,5 comparing laparoscopy with robotics, or retrospective, multicenter, comparative studies comparing TaTME with robotics,¹⁴ have shown no definitive benefits favoring either of the approaches.

Advantages for surgeons

Perhaps the 2 fundamental characteristics common to all robotic systems, which also offer advantages for surgeons, are the digitalization of surgery and connectivity.

Robotic platforms are systems with which the surgeon performs physical movements while sitting or standing at a console away from the patient, which are transformed into information. This information is transmitted at high speed to the work cart, which is physically connected to the patient, and transformed into movements of the instruments installed on said work cart. This process offers surgeons several advantages:

• 1

  Working position, or ergonomics:

  In laparoscopic, TaTME, or open rectal cancer surgery, the surgeon must maintain physical contact with the patient, sometimes adopting uncomfortable working positions for long periods of time, case after case and day after day, which takes a toll on our physical health. In robotic surgery, the ability to adjust the working position as needed to safeguard the surgeon’s physical health is an intrinsic part of the design of these systems.¹⁵

  The instruments are kept in a stable position, without the need for the surgeon to exert constant force on them to maintain the surgical field, which facilitates surgical maneuvers and significantly reduces fatigue.

• 2

  Information transmission filters, or tremor filters:

  Another clear benefit for surgeons is the ability of robotic systems to process information transmitted from the console to the work cart, eliminating what we might call “unwanted” movements, such as tremors in the surgeon’s hand, or scaling movements to make surgical motions more precise. This capability is especially helpful in vascular dissection of the lateral pelvis or in dissection of the lower third of the rectum.

• 3

  Integration of new imaging technologies or those providing guidance/identification of anatomical structures:

  Among the information-processing capabilities of surgical robots, the images that reach the surgeon’s console can be modified using the software included (in most cases; third-party programs are also used to a lesser extent, such as TilePro®, Intuitive Surgical, Sunnyvale, CA, USA). Examples of this include indocyanine green vision systems or software that can identify nerve structures and ureters, which is currently in the very early stages of implementation but will soon become a reality. This advantage is shared with advanced laparoscopic endoscopy, although not with open surgery.¹⁶ The capabilities of the computers integrated into these robotic systems are rapidly growing. This will provide more advantages for the surgeon, including the integration of Artificial Intelligence systems for real-time decision-making support.¹⁷

• 4

  Connectivity between console and work cart:

  Every robotic system is a telesurgery system in itself. As 100% of the systems installed in our setting today have system components in the same location (console, vision tower, and work cart), one of the potential advantages for surgeons is to perform or assist in procedures remotely. In complex surgical procedures, such as total mesorectal excision for rectal cancer or resections due to relapse, the applicability of this capability could be of great interest.

  Today, there are training programs that incorporate telementoring through the robotic platform thanks to console connectivity. Remote instructors can observe the surgical intervention in real time, from thousands of kilometers away, and give instructions on the console where the surgeon-in-training is working.¹⁸

  Again, this system can be particularly beneficial for surgeons performing complex procedures such as those mentioned above for the treatment of rectal cancer.

Medical-Economic considerations of robotic surgery

As previously mentioned in this manuscript, one of the major challenges facing robotic surgery today is its high implementation cost. Few studies report cost-efficiency in favor of robotic surgery in the field of colorectal surgery, and always without taking into account the initial capital investment.¹⁹ The use of this technology by more experienced surgeons, as well as the arrival of the new platforms mentioned above, could likely make robotic surgery for rectal cancer cost-effective.

Another factor to consider is the potential additional cost of surgeries performed during the training of residents or new surgeons. In this context, recent articles seem to indicate that the cost is similar in robotic surgery versus other procedures.²⁰

Given these considerations, there is no doubt that prospective studies are needed to analyze the impact of the clinical benefits of robotic surgery and the cost of its use. These studies will not only be able to analyze the operating room costs but also the overall impact of patient treatment, including the cost of postoperative complications, stoma care, and oncological outcomes, as well as patient quality of life.

Conclusion

In short, robotic surgery offers advantages for both patients and surgeons. While scientific evidence about its benefits for patients is only beginning to slowly emerge, the benefits for surgeons (improved vision, ergonomics, controlled movements, etc), have been abundantly clear for some time, even though many of these benefits are still in their infancy and have not been completely explored.

Funding

No funding for this article.