Safe Introduction of New Technologies and Techniques in Minimally Invasive Colorectal Surgery

Abstract

In the past 20 years, colorectal surgery has experienced important advances as a result of new technologies that have increasingly transformed conventional open surgery into maximal usage of minimally invasive approaches. While many tools are being developed to change the way that operations are being performed, quality must not suffer. We describe here some of the aspects to pursue to achieve optimal and safe outcomes while utilizing minimally invasive techniques such as robotic surgery, transanal total mesorectal excision, as well as the role of immunofluorescence.

Advances in surgical technology and increased computer capabilities bring new interventional therapies to another level of precision in abdominal surgery. ¹ Three decades ago, the surgical world changed directions from open surgery to laparoscopic surgery, resulting in large incisions becoming small orifices, and associated with less pain, better cosmesis, and an earlier return to full function. It became possible for hands to be utilized outside the abdomen and achieve the same or improved outcomes for patients as when they were used within . Advances in technology allowed for a camera to transform the natural three-dimensional (3D) image of the abdomen into a high-resolution, flat two-dimensional (2D) image seen by most only on television.

Yet, there was a need for adequate teaching and experience such that the learning curve to reach an ideal and acceptable level of outcomes could be achieved rapidly, reproducibly, and accurately to perform these complex surgical procedures using minimally invasive platforms. The recognition of anatomical structures, different textures, and coloration of the tissues offered by the 2D view of the video camera had to be relearned. Additionally, other factors came into play—such as the pneumodissection promoted by the pneumoperitoneum that could allow the surgeon to find the proper anatomical planes, especially in the oncological cases. On the other hand, this was something that had not been seen in traditional open surgery. Today, this knowledge is more commonplace, being passed down along several generations of surgeons, and resulting in a large accumulated experience. Yet, we are likely only embarking on the role and interplay of technology, surgeons, and surgery. Soon, artificial intelligence will help the surgeon find the safest, most accurate, and least harmful surgical route throughout the body, similar to the use of an application on your phone for transit routes, along with real-time updating. These innovations aim at greater patient safety with better quality of life and a drastic reduction of iatrogenic injuries. ^{1 2}

Throughout the previous few decades, innovations in colorectal surgery have steadily been growing, In 1982, Heald et al described their experience with total mesorectal excision (TME) for rectal cancer, which highlighted the importance of utilizing proper surgical planes and subsequently brought a significant decrease in the rates of local recurrence. Now this technique is uniformly taught as the standard of care. However, this is not in isolation. Rather, the role of a multidisciplinary evaluation is paramount. This includes a discussion of the appropriate utilization of neoadjuvant therapy as well as performing minimally invasive surgery, where appropriate, to the decrease complication rates such as sexual and urinary dysfunction and improve cosmesis without compromising oncological principles. ^{3 4 5}

Robotic surgery has allowed for the potential for increased utilization of telesurgery and guided distance surgery, aided by improved image quality and accuracy, along with the more well-known touted advantages of improved ergonomics and transitioning from 2D to 3D. Better ergonomics allow for an improved and wider implementation of intracorporeal suturing and intracorporeal resection and anastomoses. ² Despite these advantages, factors such as complex disease processes, reoperative surgery, and increased utilization of neoadjuvant radiation therapy can result in varying anatomy that surgeons could be helped through the use real-time image guidance—potentially avoiding harm to the patient. Therefore, preoperative planning with more accurate computed tomography and magnetic resonance imaging scans, as well as 3D reconstructions, allow for better definition of structures that was previously not available. ² As one example, iatrogenic autonomic nerve injury has historically been felt to be secondary to difficult visualization of the pelvic plexus, neurovascular bundles, and pudendal nerves. High-resolution imaging and computer software aids can help identify these structures while the operation is going through visual aids, color-coding, or even verbal feedback. Additionally, one of the most feared complications of bowel surgery—anastomotic leak—is also a focal point that could potentially be improved by leveraging technology toward evaluation of factors such as blood supply and tension. ¹

Thus, new technologies can allow us to more easily acquire skills that help us improve the quality of our minimally invasive surgeries and outcomes/satisfaction of our patients by both shortening the learning curve, as well as active and passive educational platforms.

Navigation Use in Colorectal Surgery

Navigation tools for minimally invasive surgery can improve the vision of surgeons with enhanced information, especially when operating on fixed anatomic targets such as the left side and rectal areas. ⁶ In this light, stereotactic navigation systems can be used for tracking structures (i.e., organs) in conjunction with preoperative images. This is an established technology in numerous surgical and interventional procedures that have already proven useful for localizing, targeting, and guiding surgical progression, even when a target cannot be seen directly. Integrating this technology into the surgical or interventional procedure enables surgeons to eliminate a significant amount of guesswork, minimize surgical invasiveness, and to a small degree, help with a lack of extensive experience. To be clear, it cannot take away from inherent technical skill or expertise.

Yet, there are obstacles that need to be overcome when utilizing these tools for colorectal surgery. Routine organ movement that occurs during the normal course of a gastrointestinal surgery—either with the surgical manipulation or positioning of the patient—causes changes in the positioning of these structures and could cause errors for the navigation. ⁷ However, the rectum is a fixed structure in the pelvis and surrounded by bone and other retroperitoneal structures that do not move much with manipulation or positioning of the patient. The pelvis therefore represents an ideal opportunity to utilize this type of navigation adjunct, especially with much more defined anatomic structures that can be used as reference markers required in navigation. As an example, with TME, the images can be maintained as an overlap throughout the surgery. ⁷ Further, stereotactic navigation has even been described in minimally invasive transanal rectal surgery ^{8 9 10 11} ( Figs. 1 2 3 4 ).

Fig. 1.

Setup of the navigation.

Fig. 2.

Location of the markers.

Fig. 3.

Anatomical area to utilize navigation.

Fig. 4.

Real-time navigation use during surgery.

Immunofluorescence

Despite upgrading in the quality of surgical images over the years, other technological enhancements are needed to improve morbidity. Complications such as fistulas, abscesses, and leaks can be caused by a lack of vascularization, occurring from 1 to 30%, with higher numbers associated with more distal anastomoses. ¹² Further, leaks are associated with other complications, take-backs, and mortality rates ranging from 6 to 22%. ¹²

Even with a wealth of experience, surgeons can occasionally have difficulty in determining the ideal area of bowel to use to help construct a safe anastomoses. Further, it is sometimes hard to delineate areas of poor tissue oxygenation with the naked eye. ^{13 14} In fact, many factors need to be considered to evaluate the quality of an anastomosis, such as color, temperature, bleeding, and tissue quality. ^{15 16} Having reliable tools to help with this has important considerations and potential implications. Indocyanine green (ICG) is a sterile, anionic, water-soluble, but relatively hydrophobic, tricarbocyanine molecule that has been utilized in this light. Once injected into the vascular system, it binds to plasma proteins. Based on its ability to become fluorescent when excited by near-infrared light, ICG can be used to help quantify things such as perfusion. ¹⁷

Several fluorescent angiography systems are currently available for laparoscopic and open surgery, including the Stryker 1588 AIM Platform (Portage, MI), PINPOINT (Novadaq, Mississauga, ON, Canada), the D-Light NIR/ICG (Karl Storz, Tuttlingen, Germany), IC-View (Pulsion Medical Systems, Munich, Germany), PDE-neo System (Hamamatsu Photonics, Hamamatsu, Japan), the SPY Elite Kit (LifeCell Corporation, Bridgewater, NJ), and the da Vinci Firefly robotic surgical system (Intuitive Surgical, Sunnyvale, CA). This technology has potential advantages in colorectal surgery for visualizing the vascularization of the anastomosis and thus avoiding leak and early fistulas ( Figs. 5 and 6 ). In theory, the use of ICG can be used to help ensure appropriate blood flow to the area, especially when the bowel serosal appearance may not match the perfusion at the mucosal level. ^{18 19} Finally, there are other uses in colorectal surgery, such real-time visualization of the lymph node drainage and ureteral identification. ²⁰ Unfortunately, the true effectiveness and impact of ICG to demonstrate these theoretical advantages into documented improvements remains to be fully delineated.

Fig. 5.

Area to be analyzed with indocyanine green (ICG).

Fig. 6.

Area after injection of indocyanine green (ICG) (note: green demonstrates the vascularization).

Robotic Surgery

Advances in robotic colorectal surgery are limited by the speed of technological discovery, costs of the equipment, and the willingness of surgeons to incorporate these new devices into their procedures. While continued efforts are ongoing to help decrease costs and improve equipment, each are required likely to witness the widespread adoption of robotic surgery. Hospitals that can increase the number of robotic procedures performed can reduce the costs-per-case, though this may take substantial volume and teamwork. Unfortunately, volumes may not be available at every institution. Even with these modifications, it will not reduce the costs of purchasing and maintaining the robotic system. Several established and emerging platforms are in place, which may lead to lower prices as well as technological innovations, similar to laparoscopy. Also similar to laparoscopy, as robotic use becomes a standard part of the curriculum of most trainees, the robotic approach may simply become another tool in the armamentarium of colorectal surgeons.

Several of the new robotic systems have focused on improving existing systems and incorporating new technology. These include the use of reusable endoscopic instruments and incorporation of haptic feedback technology—the latter of which has been a sticking point for many surgeons to date. Other systems have been trying to take advantage of the improved maneuverability of robotics to optimize the technology for single-port surgeries. Smaller surface area equipment with more maneuverability prevents crowding and external collisions of the instruments, improved docking, and efficiencies in the operating room. Another approach has been to incorporate techniques to utilize operating through natural orifices (Natural Orifice Translumenal Endoscopic Surgery [NOTES]). Currently, some of these devices are too large and still require multiple incisions; however, NOTES has been used successfully in porcine models and early human reports, and could represent a novel advance.

This may be simply the beginning, as the future of robotic use in surgery is constantly evolving. The development of new safe and cost-efficient technologies opens the door to everything from nanorobots to artificially intelligent performed procedures. The latter concept is one where the surgeon actively uses concurrent data collection and digitalization of imaging. New generations of surgeons will receive earlier and broader training in these techniques and be more comfortable with their application. With the greater number of technology and procedures finding their way into clinical practice, it will be important to update guidelines for the safe introduction of new technologies and techniques such as that proposed by the Society of American Gastrointestinal and Endoscopic Surgeons in 2014. ²¹ In part, surgical societies could provide assessments of new technology and techniques in a timely fashion to aid surgeons with their decision-making when contemplating the introduction of new technology and techniques. Surgeons considering the introduction of new technology and techniques in their practice should have device- or procedure-specific training to decrease learning curve-related complications and thus improve patient safety. While a minor device or procedure modification may only require familiarization of the surgeon, more substantial changes would necessitate a more elaborate introduction process including familiarization, cognitive training, hands-on practice, performance assessment, patient disclosure, proctoring, and local and national outcome monitoring. The necessary training steps depend on the degree of novelty/change and may include informal familiarization of surgeon with the device or procedure before its introduction; review of existing data/literature; the pursuit of expert input; video review of device use or procedure; practice on appropriate simulated, animate, or cadaveric training models; course participation at society meetings; proctoring or teleproctoring of initial cases; and team training. The effectiveness compared with alternatives, cost, patient outcomes, and the safety profile of new technology and techniques should always be assessed prior to and after their introduction. Other parameters such as existing and required resources; benefits to patients, surgeons, and hospitals; existing or anticipated volume of use; barriers to adoption; and whether the anticipated benefits prove real after introduction should also be considered.

Transanal Total Mesorectal Excision

After the description of a TME for rectal cancer by Heald in the 1980s, the importance of preserving an intact mesorectum to not only improve the quality of the resection, but also maximize its associated oncological benefits such as decreased local recurrence, has become indisputable. ³ Since then, various platforms have emerged to follow the oncological principles of TME, but incorporate minimally invasive techniques. Initially, this was via approaches such as transanal/transabdominal, then hand-assisted and straight laparoscopy, then robotic, and now transanal TME (taTME). ²²

For many surgeons this approach is not new, since perineal surgeries for resection of rectum have long existed—such as the perineal rectosigmoidectomy (i.e., Altemeier procedure). Yet, the incorporation of laparoscopic (and now robotic) tools was new, with the goals of improving vision, perioperative outcomes, and a focus on improving a clear distal margin rate. From the first report of transanal endoscopic surgeries performed on pig carcasses ²³ to the first clinical experience, ²² rigid transanal endoscopic access platforms (such as the transanal endoscopic microsurgery, or transanal endoscopic operations) or flexible (transanal minimally invasive surgery [TAMIS]) have been shown to be feasible and safe with good oncological outcomes. Yet, taking the next step to removing the rectum in its entirety was an entirely different prospect. It is known that total excision of the mesorectum can be difficult when performed via an abdominal approach, especially in obese male patients with distal tumors located on the anterior rectum. Now, turning the anatomy “upside down,” with the transanal approach introduces further complexities to an already potentially difficult procedure. In this operation, a combined abdominal and transanal approach is performed to complete the TME. The abdominal part of the operation utilizes a laparoscopic or robotic approach, including mobilization of the splenic flexure, high ligation of the inferior mesenteric artery and vein, and complete mobilization of the transverse distal to the superior rectum. Simultaneously or at the end of the abdominal portion, the flexible platform is introduced for the taTME. At the end of the “retrograde” dissection, the entire mobilized left colon can often be externalized by the anus. The specimen is sectioned, and an end-to-end coloanal anastomosis is performed using the circular stapler or hand-sewn technique and a diverting ileostomy is performed from above.

Therefore, the TAMIS-TME approach may be preferable based on the location of the tumor, patient body habitus, and prior abdominal procedures, such as those in the anterior wall of the medial/distal rectum. Although the oncological outcomes associated with TAMIS-TME need to be validated in prospective multicenter studies, implementing this technique provides additional challenges and associated obstacles that remain to be determined. However, it is clear that this is another potential useful tool for select patients.

Future

Nowadays, the evolution of the surgical instruments is critical to advancing colorectal surgery and allows us to achieve the best outcomes possible. Going ahead it is always valuable to put into context the past—as the knowledge we gain in the daily learning process of multiple tasks and realities over the years brings us experience. Until now robotic surgery is only about mechanics. We focus on control of the camera, instruments, and wrist movements. But with development of artificial intelligence or software guidance surgery, we enter in a new era of surgery. A computer attached to the robotic systems may totally distinguish different metrics and allow for skills to be taught and improved driven by more than subjective metrics. The use of artificial intelligence can account for anatomical variations or unusual anatomy to immediately recognize warning signals such as impending potential complications and drive the surgeon toward better decision-making in real time. Thus, the digital experience will help drive clinical improvements leading to improvements of patients' outcomes.

Conclusion

New technologies in the realm of minimally invasive surgery not only provides simpler ways of a surgical approach, but also a wide array of new procedures with less trauma to patients and faster recovery of their activities. Thus, we believe the future will continue to increasingly bring promising and innovative safety initiatives to aid in performance of minimally invasive surgery.