Combined robotic transanal total mesorectal excision (R-taTME) and single-site plus one-port (R-SSPO) technique for ultra-low rectal surgery-initial experience with a new operation approach

Clean visual field reconstruction in robot-assisted laparoscopic surgery based on dynamic prediction

Robot-assisted minimally invasive surgery has been broadly employed in complicated operations. However, the multiple surgical instruments may occupy a large amount of visual space in complex operations performed in narrow spaces, which affects the surgeon's judgment on the shape and position of the lesion as well as the course of its adjacent vessels/lacunae. In this paper, a surgical scene reconstruction method is proposed, which involves the tracking and removal of surgical instruments and the dynamic prediction of the obscured region. For tracking and segmentation of instruments, the image sequences are preprocessed by a modified U-Net architecture composed of a pre-trained ResNet101 encoder and a redesigned decoder. Also, the segmentation boundaries of the instrument shafts are extended using image filtering and a real-time index mask algorithm to achieve precise localization of the obscured elements. For predicting the deformation of soft tissues, a soft tissue deformation prediction algorithm is proposed based on dense optical flow gravitational field and entropy increase, which can achieve local dynamic visualization of the surgical scene by integrating image morphological operations. Finally, the preliminary experiments and the pre-clinical evaluation were presented to demonstrate the performance of the proposed method. The results show that the proposed method can provide the surgeon with a clean and comprehensive surgical scene, reconstruct the course of important vessels/lacunae, and avoid inadvertent injuries.

Robotic versus laparoscopic left colectomy with complete mesocolic excision for left-sided colon cancer: a multicentre study with propensity score matching analysis

PURPOSE

Robotic surgery for right-sided colon and rectal cancer has rapidly increased; however, there is limited evidence in the literature of advantages of robotic left colectomy (RLC) for left-sided colon cancer. The purpose of this study was to compare the outcomes of RLC versus laparoscopic left colectomy (LLC) with complete mesocolic excision (CME) for left-sided colon cancer.

METHODS

Patients who had RLC or LLC with CME for left-sided colon cancer at five hospitals in China between January 2014 and April 2022 were included. A one-to-one propensity score matched analysis was performed to decrease confounding. The primary outcome was postoperative complications occurring within 30 days of surgery. Secondary outcomes were disease-free survival, overall survival and the number of harvested lymph nodes.

RESULTS

A total of 292 patients (187 male; median age 61.0 [20.0-85.0] years) were eligible for this study, and propensity score matching yielded 102 patients in each group. The clinicopathological characteristics were well-matched between groups. The two groups did not differ in estimated blood loss, conversion to open rate, time to first flatus, reoperation rate, or postoperative length of hospital stay (p > 0.05). RLC was associated with a longer operation time (192.9 ± 53.2 vs. 168.9 ± 52.8 min, p = 0.001). The incidence of postoperative complications did not differ between the RLC and LLC groups (18.6% vs. 17.6%, p = 0.856). The total number of lymph nodes harvested in the RLC group was higher than that in the LLC group (15.7 ± 8.3 vs. 12.1 ± 5.9, p < 0.001). There were no significant differences in 3-year and 5-year overall survival or 3-year and 5-year disease-free survival.

CONCLUSION

Compared to laparoscopic surgery, RLC with CME for left-sided colon cancer was found to be associated with higher numbers of lymph nodes harvested and similar postoperative complications and long-term survival outcomes.

Robotic versus laparoscopic left colectomy with complete mesocolic excision for left-sided colon cancer: a multicentre study with propensity score matching analysis

BACKGROUND

Robotic surgery for right-sided colon and rectal cancer has rapidly increased; however, there is limited evidence in the literature of advantages of robotic left colectomy (RLC) for left-sided colon cancer. The purpose of this study was to compare the outcomes of RLC versus laparoscopic left colectomy (LLC) with complete mesocolic excision (CME) for left-sided colon cancer.

METHODS

Patients who had RLC or LLC with CME for left-sided colon cancer at 5 hospitals in China between January 2014 and April 2022 were included. A one-to-one propensity score matched analysis was performed to decrease confounding. The primary outcome was postoperative complications occurring within 30 days of surgery. Secondary outcomes were disease-free survival, overall survival and the number of harvested lymph nodes.

RESULTS

A total of 292 patients (187 males; median age 61.0 [20.0-85.0] years) were eligible for this study, and propensity score matching yielded 102 patients in each group. The clinical-pathological characteristics were well-matched between groups. The two groups did not differ in estimated blood loss, conversion to open rate, time to first flatus, reoperation rate, or postoperative length of hospital stay (p > 0.05). RLC was associated with a longer operation time (192.9 ± 53.2 vs. 168.9 ± 52.8 minutes, p=0.001). The incidence of postoperative complications did not differ between the RLC and LLC groups (18.6% vs. 17.6%, p = 0.856). The total number of lymph nodes harvested in the RLC group was higher than that in the LLC group (15.7 ± 8.3 vs. 12.1 ± 5.9, p< 0.001). There were no significant differences in 3-year and 5-year overall survival or 3-year and 5-year disease-free survival.

CONCLUSIONS

Compared to laparoscopic surgery, RLC with CME for left-sided colon cancer was found to be associated with higher numbers of lymph nodes harvested and similar postoperative complications and long-term survival outcomes.

Robotic Transanal Total Mesorectal Excision Compared to Laparoscopic Transanal Total Mesorectal Excision: Oncologic Results of the Past 5 Years

Colorectal cancer is one of the deadliest diseases on the planet. Rectal cancer (RC) is the 8 th most common type of cancer disease worldwide, accounting for over 300,000 fatalities in 2018. Total mesorectal excision (TME) is considered as the gold standard approach for surgical RC management. To alleviate technical problems associated with dissection of distal rectal, transanal procedure to mesorectum was developed. The robotic operating platforms’ development has brought about the most significant change. The robotic method, which was described first in the year 2001, is gaining popularity in colorectal surgery. A stable camera platform with three-dimensional imaging and tremor filtering, motion scaling, instruments with numerous degrees of freedom, 3 rd arm for fixed retraction, ambidextrous capability, superior ergonomics, and less fatigue, all these advantages have all influenced robotics implementation. However, there are certain disadvantages to robotic surgery, such as high expenses, lengthy time of operation, a bulky cart, and absence of haptic sense. Robotic transanal TME (R-TA TME) is unique method that integrates potential advantages of perineal dissection with precise control of distal margins, along with all robotic technology advantages with respect to dexterity and greater precision. This review goal is to evaluate the available literature critically regarding R-TA TME in comparison to laparoscopic TA TME (L-TA TME) using the most prevalent histopathological metrics, which are the circumferential resection margin, the distal rectal margin, recurrence rate, specimen quality, advantages, and disadvantages. Oncological results for the past 5 years were used. The resources were obtained from electronic sources such as Google Scholar and PubMed. The conclusion of this review revealed that R-TA TME is as safe as well as feasible as L-TA TME, is technically possible, and has comparable oncological results and short-term post-operative outcomes. However, further investigation is required to evaluate long-term oncological or functional results.

Robotic Surgery in Rectal Cancer: Potential, Challenges, and Opportunities

The current standard treatment for locally advanced rectal cancer is based on a multimodal comprehensive treatment combined with preoperative neoadjuvant chemoradiation and complete surgical resection of the entire mesorectal cancer. For ultra-low cases and cases with lateral lymph node metastasis, due to limitations in laparoscopic technology, the difficulties of operation and incidence of intraoperative complications are always difficult to overcome. Robotic surgery for the treatment of rectal cancer is an emerging technique that can overcome some of the technical drawbacks posed by conventional laparoscopic approaches, improving the scope and effect of radical operations. However, evidence from the literature regarding its oncological safety and clinical outcomes is still lacking. This brief review summarized the current status of robotic technology in rectal cancer therapy from the perspective of several mainstream surgical methods, including robotic total mesorectal excision (TME), robotic transanal TME, robotic lateral lymph node dissection, and artificial intelligence, focusing on the developmental direction of robotic approach in the field of minimally invasive surgery for rectal cancer in the future.

Clinical Status and Future Prospects of Transanal Total Mesorectal Excision

Low rectal cancer has always posed surgical challenges to gastrointestinal surgeons. Transanal total mesorectal excision (taTME) is a novel approach to radical resection for low rectal cancer. Compared with conventional laparoscopic TME (laTME), taTME is relevant to the benefits of better vision of the mesorectal plane, feasibility of operating in a narrow pelvis, and exact definition of distal resection margin, which may lead to a higher possibility of free circumferential resection margin, better quality of TME specimen, and lower conversion rate. Although there are concerns about its long-term oncological outcomes and complex learning curve, taTME is a promising alternative for rectal cancer. In this review, we discuss the application status and prospects of taTME.

Locally Advanced Rectal Cancer: What We Learned in the Last Two Decades and the Future Perspectives

The advancement in surgical techniques, optimization of systemic chemoradiotherapy, and development of refined diagnostic and imaging modalities have brought a phenomenal shift in the treatment of the locally advanced rectal cancer. Although each therapeutic option has shown substantial progress in their field, it is finding their ideal amalgamation which has baffled the clinician and researchers alike. In the effort to identifying the perfect salutary treatment plan, we have even shifted our attention from the trimodal approach to non-operative "watchful waiting" to more recent individualized care. In this article, we acknowledge the scientific progress in the management of locally advanced rectal cancer and compare the opportunities as well as the obstacles while implementing them clinically. We also explore the current challenges and controversies surrounding the multidisciplinary approach and highlight the new trends and recent advances with an ultimate goal to improve the patients' quality of life.

Robotic transanal total mesorectal excision: Is the future now?

Total mesorectal excision (TME) is the standard surgical treatment for the curative radical resection of rectal cancers. Minimally invasive TME has been gaining ground favored by the continuous technological advancements. New procedures, such as transanal TME (TaTME), have been introduced to overcome some technical limitations, especially in low rectal tumors, obese patients, and/or narrow pelvis. The earliest TaTME reports showed promising results when compared with the conventional laparoscopic TME. However, recent publications raised concerns regarding the high rates of anastomotic leaks or local recurrences observed in national series. Robotic TaTME (R-TaTME) has been proposed as a novel technique incorporating the potential benefits of a perineal dissection together with precise control of the distal margins, and also offers all those advantages provided by the robotic technology in terms of improved precision and dexterity. Encouraging short-term results have been reported for R-TaTME, but further studies are needed to assess the real role of the new technique in the long-term oncological or functional outcomes. The present review aims to provide a general overview of R-TaTME by analyzing the body of the available literature, with a special focus on the potential benefits, harms, and future perspectives for this novel approach.

Robotic Transanal Total Mesorectal Excision (RTaTME): State of the Art

Total mesorectal excision (TME) is the gold standard technique for the surgical management of rectal cancer. The transanal approach to the mesorectum was introduced to overcome the technical difficulties related to the distal rectal dissection. Since its inception, interest in transanal mesorectal excision has grown exponentially and it appears that the benefits are maximal in patients with mid-low rectal cancer where anatomical and pathological features represent the greatest challenges. Current evidence demonstrates that this approach is safe and feasible, with oncological and functional outcome comparable to conventional approaches, but with specific complications related to the technique. Robotics might potentially simplify the technical steps of distal rectal dissection, with a shorter learning curve compared to the laparoscopic transanal approach, but with higher costs. The objective of this review is to critically analyze the available literature concerning robotic transanal TME in order to define its role in the management of rectal cancer and to depict future perspectives in this field of research.

SP rTaTME: initial clinical experience with single-port robotic transanal total mesorectal excision (SP rTaTME)

BACKGROUND

The technical difficulty and steep learning curve of transanal total mesorectal excision (taTME) has limited widespread adoption. The single-port (SP) daVinci robot is designed to facilitate single-incision and natural-orifice transluminal endoscopic surgery (NOTES). This paper describes the first clinical experience of single-port robotic taTME (SP rTaTME).

METHODS

This was a prospective study on consecutive patients with rectal cancer who underwent SP rTaTME proctosigmoidectomy with handsewn coloanal anastomosis in December 2018 and January 2019. The primary outcome was technical feasibility of the procedure. The secondary outcomes include blood loss, intraoperative complications, length of hospital stay, quality of the TME specimen, short- and long-term morbidity and mortality, as well as short-term oncologic follow -up.

RESULTS

There were two patients, a 48-year-old male and a 38-year-old female. Both operations were completed successfully without complications or conversion. Estimated blood loss was 200 mL and 130 mL. In both cases the TME was completed transanally using the SP robot. In the first patient, the abdominal portion was completed through an abdominal single-incision; in the second patient the operation was entirely performed transanally as a pure NOTES procedure. In both cases, the final pathology report showed a complete TME with negative margins. Patients were discharged on postoperative day 3 and 4,respectively. There was no long-term morbidity or mortality.

CONCLUSIONS

SP rTaTME is feasible and can be safely performed. It provides excellent optics and dexterity to work in a limited space. Future studies are required to further define the safety profile and the ultimate utility of the SP robot for taTME.

Short-term outcomes of medium-low rectal cancer treated by taTME and experience of 22 cases

BACKGROUND AND METHODS

Transanal total mesorectal excision (taTME) is a novel radical resection technique that may address the unsatisfactory functional and oncological outcomes of medium-low rectal cancers. Although its oncological safety remains unclear, taTME has demonstrable value in surgery, complications, and oncological outcomes. Here, we explore the short-term outcomes of rectal cancer after taTME and discuss the surgical experience. Twenty-two patients with medium-low rectal cancer who underwent taTME were retrospectively evaluated. Comprehensive demographic, oncological, and clinical data were analyzed and the perioperative state and postoperative follow-up were evaluated.

RESULTS

Over a median follow-up period of 24.4 (4-36) months, local recurrence occurred in one patient at 6 months postsurgery. Fecal incontinence was the most common postoperative complication, and 3-6 months of pelvic-floor-rehabilitation training greatly improved  anal function CONCLUSIONS: taTME achieved satisfactory short-term outcomes in oncological complications and postoperative functions. Accurate intraoperative anatomical location, identification of the rectovesical fascia, and neuroprotection are critical. However, this procedure has a steep learning curve, and large samples and multicenter studies are required to substantiate its effectiveness.

DISCUSSION

We retrospectively analyzed the oncological and functional prognosis of 22 patients with colorectal cancer undergoing taTME surgery and preliminarily concluded taTME can be regarded as a safe and feasible treatment.

Robotics Total Mesorectal Excision Up To the Minute

Surgical techniques have evolved over the past few decades, and minimally invasive surgery has been rapidly adapted to become a preferred operative approach for treating colorectal diseases. However, many of the procedures remain a technical challenge for surgeons to perform laparoscopically, which has prompted the development of robotic platforms. Robotic surgery has been introduced as the latest advance in minimally invasive surgery. The present article provides an overview of robotic rectal surgery and describes many advances that have been made in the field over the past two decades. More specifically, the introduction of the robotic platform and its benefits, and the limitations of current robotic technology, are discussed. Although the main advantages of robotic surgery over conventional laparoscopy appear to be lower conversion rates and better surgical specimen quality, oncological and functional outcomes appear to be similar to those of other alternatives. Other potential benefits include earlier recovery of voiding and sexual function after robotic total mesorectal excision. Nevertheless, the costs and lack of haptic feedback remain the primary limitations to the widespread use of robotic technology in the field.

Comparison of the perioperative outcomes of laparoscopic surgery, robotic surgery, open surgery, and transanal total mesorectal excision for rectal cancer: An overview of systematic reviews

Regarding the surgical approaches for rectal cancer, many techniques have been reported in randomized controlled trials, meta-analyses, and reviews of comparisons between two techniques, e.g. open surgery vs laparoscopic surgery, laparoscopic surgery vs robotic surgery, or laparoscopic surgery vs transanal total mesorectal excision. Since robotic surgery and transanal total mesorectal excision were developed after laparoscopic surgery had become an established minimally invasive technique, they have each been compared with laparoscopic surgery. Therefore, a review was performed to compare the surgical outcomes of robotic surgery and transanal total mesorectal excision, and to perform such comparisons among ≥3 of the above mentioned approaches, in the expectation that this review will serve as a reference for aiding treatment selection in future. The results of the current review suggest that all of the examined procedures have advantages and disadvantages, but that there are no decisive factors that could be used to select one procedure over any other. At the present time it cannot be demonstrated that laparoscopic surgery, robotic surgery, transanal total mesorectal excision, or open surgery is superior to the other techniques, and it is important to select the best technique for each patient from among those that a surgeon can perform. It is also important to maintain a flexible attitude that allows new techniques to be adopted as needed in the future.

Robotic-assisted transanal total mesorectal excision for rectal cancer: technique and results from a single institution

BACKGROUND

Total mesorectal excision (TME) has greatly reduced the local recurrence rate of rectal cancer after colorectal surgery. Transanal TME (TaTME) is potentially a suitable option for patients with mid and low rectal cancer. Robotic systems overcome the limitations of laparoscopic surgery. The aim of this study was to investigate the safety and feasibility of robotic-assisted transanal total mesorectal excision (RTaTME) in patients with rectal cancer.

METHODS

The clinical data of patients who underwent RTaTME for rectal cancer between May 2017 and January 2020 were reviewed. The perioperative data and short-term outcomes of all the patients were retrospectively analysed. Last follow-up was in May 2020.

RESULTS

A total of 13 patients had RTaTME during the 36-month study period. The median docking time was 18 (IQR 16-20) minutes, median transanal phase time was 95 (IQR 74-100) minutes, median total operation time was 240 (IQR 195-270) minutes, median estimated blood loss was 60 (IQR 50-100) ml, the median number of lymph nodes retrieved was 15 (IQR 13-16) and median length of postoperative hospital stay was 7 (IQR 6-10) days. There was no mortality. Three (23%) patients suffered a postoperative complication including one anastomotic leak and one prolonged ileus, none of them required any intervention. Patients were followed up for a median of 15 (IQR 11-18) months, and no local tumour recurrences, metastasis or deaths were reported.

CONCLUSIONS

Our preliminary results suggest that RTaTME for rectal cancer is feasible. This innovative approach may offer patients potential benefits-further studies are needed.

Robotic surgery for colorectal disease: review of current port placement and future perspectives

Purpose

As robotic surgery is increasingly performed in patients with colorectal diseases, understanding proper port placement for robotic colorectal surgery is necessary. This review summarizes current port placement during robotic surgery for colorectal diseases and provides future perspective on port placements.

Methods

PubMed were searched from January 2009 to December 2018 using a combination of the search terms “robotic” [MeSH], “colon” [MeSH], “rectum” [MeSH], “colorectal” [MeSH], and “colorectal surgery” [MeSH]. Studies related to port placement were identified and included in the current study if they used the da Vinci S, Si, or Xi robotic system and if they described port placement.

Results

This review included 77 studies including a total of 3,145 operations. Fifty studies described port placement for left-sided and mesorectal excision; 17, 3, and 7 studies assessed port placement for right-sided colectomy, rectopexy, transanal surgery, respectively; and one study assessed surgery with reduced port placement. Recent literatures show that the single-docking technique included mobilization of the second and third robotic arms for the different parts without movement of patient cart and similar to previous dual or triple-docking technique. Besides, use of the da Vinci Xi system allowed a more simplified port configuration.

Conclusion

Robot-assisted colorectal surgery can be efficiently achieved with successful port placement without movement of patient cart dependent on the type of surgery and the robotic system.

Evolution of surgery for rectal cancer: Transanal total mesorectal excision～new standard or fad?～

Transanal Total Mesorectal Excision (TaTME) has recently been developed to overcome the difficulties associated with conventional laparoscopic or robotic TME. TaTME has gained popularity and becomes the center of attention among colorectal surgeons globally. The present review aims to update the literature, clarify the current status and perspectives of TaTME. Complete TaTME specimens were obtained in 85-97.1% of the case; the reported circumferential resection margin (CRM) ranged from 1.5% to 8.1%, whereas and distal resection margin (DRM) positive rates ranged from 0% to 3.2%. The conversion rate of TaTME occurred from 0 to 15%, and there was no difference between TaTME and laparoscopic or robotic TME. Intraoperative complications occurred in 5-6% of the case, which compared favorably to laparoscopic TME. The most serious intraoperative complication with this approach was urethral injury, although only small numbers were reported, which was possibly due to under-reporting. Clavien-Dindo I or II postoperative complications occurred in 22-24% of the case, and III or IV in 10-11% of the case, which did not differ between TaTME and laparoscopic or robotic TME. TaTME may be technically easier and more beneficial than laparoscopic, robotic or open TME in male patients with a narrow pelvis; in obese patients with a bulky tumor. At present two randomized controlled trials, COLOR III and GRECCAR, and comparing TaTME with laparoscopic TME are being conducted and their outcomes are awaited. TaTME is a complex procedure, but proved to be feasible, oncologically safe, and effective in difficult cases. Before this new technique is adopted, proper training with Proctor/mentorship is strongly advised. Careful case selection and audit of data are mandatory.

Feasibility of transanal total mesorectal excision (taTME) using the Medrobotics Flex® System

BACKGROUND

The use of transanal total mesorectal excision (taTME) for treatment of rectal cancer is growing, but anatomic constraints prevent access to the proximal rectum with rigid instruments. The articulated instrumentation of current surgical robots is promising in overcoming these limitations, but the bulky size of current platforms inhibits the proximal reach of dissection. Flexible robotic systems could overcome these constraints while maintaining a stable platform for dissection. The goal of this study was to evaluate feasibility of performing taTME using the semi-robotic Flex® System (Medrobotics Corp., Raynham, MA) in human cadavers.

METHODS

taTME was performed by two surgeons in six fresh human cadaveric specimens using the Flex® System, with or without transabdominal laparoscopic assistance. Both mid- and low-rectal lesions were simulated. Metrics including quality of visualization, maintenance of pneumorectum, maneuverability of instruments, effectiveness of pursestring suture placement, and dissection in an anatomically correct plane were evaluated.

RESULTS

The semi-robotic endoluminal platform allowed for excellent visualization, insufflation, and dissection during taTME. Adequate pursestring occlusion of the rectum was achieved in all six cases. In cadavers with simulated mid-rectal lesions (N = 4), dissection and anterior peritoneal entry was achieved in all cases, with abdominal assistance utilized in two of four cases. In cadavers with simulated low-rectal lesions (N = 2), dissection was incomplete and aborted due to difficulty maneuvering instruments in close proximity to the rigid transanal port.

CONCLUSIONS

Use of the Flex® system for taTME is feasible for mid-rectal dissection. Advantages over the traditional multi-armed robot include longer reach of instruments with the ability to dissect up to 17 cm from the anal verge, as well as tactile feedback. The current design of the flexible platform does not permit safe dissection in the distal rectum, although this constraint may be resolved with future adjustments to the equipment.

Robotic transanal total mesorectal excision assisted by laparoscopic transabdominal approach: A preliminary twenty-case series report

BACKGROUND

Laparoscopy-assisted robotic transanal total mesorectal excision is a novel surgical technique for rectal cancer resection. Compared to prior DaVinci Si system case series, this case series is the first to report robotic taTME assisted by laparoscopy (r-taTME) in which the "transanal team" operates via the DaVinci Xi system. As a result, we aim to delineate and discuss preliminary findings from our robotic taTME experiences.

METHODS

A total of twenty patients (twelve males) who underwent robotic taTME assisted by laparoscopy (r-taTME) between January 2016 and November 2016 at a single institution were documented. Surgical outcomes, including complications, pathological outcomes, and short-term results, were then retrospectively analyzed.

RESULTS

All patients underwent r-taTME via a two-team approach. The "abdominal team" operated via a single port method (ileostomy site), while the "transanal team" operated via the DaVinci Xi system. The mean patient age was 56.7 ± 14.3 years (range 31-79), and the mean distance from tumor to anal verge was 6.0 ± 2.7 cm (range 2-10). The mean estimated intraoperative blood loss was 88 ± 107 ml (range 30-500), and circular stapling was utilized to restore continuity in 80% of study patients. The overall postoperative complication rate was 35%, and the mean distal margin length was 3.1 ± 1.3 cm. There were three patients who had a circumferential margin (CRM) involved by cancer cells (≤1 mm).

CONCLUSION

Our preliminary series report demonstrates that utilization of r-taTME assisted by laparoscopy is safe and feasible. Development of a novel transanal approach that allows single-port access alongside a multi-arm robotic system may increase the convenience and efficiency of future operation.

Transanal total mesorectal excision (TaTME): current status and future perspectives

Total mesorectal excision (TME) is the gold standard surgical treatment for mid- and low rectal cancer; however, it is associated with specific technical hurdles. Transanal TME (TaTME) is a new procedure developed to overcome these difficulties, through an enhanced visualization of the dissection plane. This potentially could result in a more accurate distal dissection with a lower rate of positive circumferential resection margins, increasing the rate of sphincter-saving procedures. The indications for TaTME are currently expanding, despite not being yet standardized, and structured training programs are ongoing to help overcome the steep learning curve related to the technique. The procedure is feasible and safe with similar intraoperative complications and readmission rates when compared with conventional open or laparoscopic TME. Favorable short-term oncologic results have been reported: in particular, TaTME is associated with mesorectal specimen of a better quality and a longer distal resection margin that is established at the beginning of the procedure under direct view. Robotics, when available, will probably overcome the steep learning curve related to the complexity of TaTME. Long-term follow-up and ongoing RCT trials data are awaited regarding functional results, local recurrence and survival, and to facilitate the comparison with standard laparoscopic or robotic rectal resections. The present review is focused on critically analyzing the theoretical benefits and risks of the procedure, its indications, short- and long-term results and future direction in the application of TaTME.

Robotic-assisted stereotactic real-time navigation: initial clinical experience and feasibility for rectal cancer surgery

BACKGROUND

Real-time stereotactic navigation for transanal total mesorectal excision has been demonstrated to be feasible in small pilot series using laparoscopic techniques. The possibility of real-time stereotactic navigation coupled with robotics has not been previously explored in a clinical setting.

METHODS

After pre-clinical assessment, and configuration of a robotic-assisted navigational system, two patients with locally advanced rectal cancer were selected for enrollment into a pilot study designed to assess the feasibility of navigation coupled with the robotic da Vinci Xi platform via TilePro interface. In one case, fluorescence-guided surgery was also used as an adjunct for structure localization, with local administration of indocyanine green into the ureters and at the tumor site.

RESULTS

Each operation was successfully completed with a robotic-assisted approach; image-guided navigation provided computed accuracy of ± 4.5 to 4.6 mm. The principle limitation encountered was navigation signal dropout due to temporary loss of direct line-of-sight with the navigational system's infrared camera. Subjectively, the aid of navigation assisted the operating surgeon in identifying critical anatomical planes. The combination of fluorescence with image-guided surgery further augmented the surgeon's perception of the operative field.

CONCLUSIONS

The combination of stereotactic navigation and robotic surgery is feasible, although some limitations and technical challenges were observed. For complex surgery, the addition of navigation to robotics can improve surgical precision. This will likely represent the next step in the evolution of robotics and in the development of digital surgery.

Enabling single-site laparoscopy: the SPORT platform

BACKGROUND

The Single Port Orifice Robotic Technology (SPORT) Surgical System by Titan Medical Inc. is designed to overcome the inherent challenges of minimally invasive single-access procedures. The aim of this preclinical study was to evaluate the feasibility of various digestive surgery procedures using this novel surgical robotic platform.

METHODS

A total of 12 minimally invasive procedures were performed on six pigs (5 cholecystectomies, 3 Nissen fundoplications, 1 splenectomy and 1 hepatic pedicle dissection) and on one human cadaver (1 cholecystectomy and 1 Nissen fundoplication), by four laparoscopic surgeons. The usability of the device was assessed by means of the modified objective structured assessment of technical skills (OSATS) score that was calculated and analyzed by two independent observers on the recorded videos. Surgeon feedback and recommendations were systematically recorded.

RESULTS

All procedures were successfully completed with the SPORT system. In general, surgeons reported to appreciate the intuitive interface and controls, the high-resolution 3D imaging, the dexterity of the end-effectors, and the ergonomic open control platform. Some features requiring optimization were also identified. The modified OSATS score demonstrated a learning curve effect for all device-related tasks.

CONCLUSIONS

A variety of abdominal procedures could be safely completed with the current SPORT prototype, in the preclinical setting. This preliminary feasibility experience is promising and encourages further development of single-port robotically assisted surgery.

Robot-guided neuromapping during nerve-sparing taTME for low rectal cancer

PURPOSE

Intraoperative pelvic neuromapping with electrophysiological evaluation of autonomic nerve preservation during robotic total mesorectal excision (TME) for rectal cancer is conventionally performed by the bedside assistant with a hand-guided probe. Our goal was to return autonomy over the neuromonitoring process to the colorectal surgeon operating the robotic console.

METHODS

A recently described prototype microfork electrostimulation probe was evaluated intraoperatively during abdominal robotic-assisted transanal TME (taTME) surgery for low rectal cancer in three consecutive male patients.

RESULTS

An intraoperative video demonstrates the good control and maneuverability of the prototype probe with electrophysiological confirmation of bilateral pelvic autonomic nerve preservation.

CONCLUSIONS

This study presents the first in situ application of a new microfork probe for fully robot-guided neuromapping in three patients undergoing TME surgery for low rectal cancer.

Appraisal and Current Considerations of Robotics in Colon and Rectal Surgery

BACKGROUND

Robotic technology aims to obviate some of the limitations of conventional laparoscopic surgery, yet the role of robotics in colorectal surgery is still largely undefined and varies with respect to its application in abdominal versus pelvic surgery.

METHODS

With this review, we aimed to highlight current developments in colorectal robotic surgery. We systematically searched the following databases: PubMed, EMBASE, and Cochrane Library. We critically reviewed the available literature on the use of robotic technology in colon and rectal surgery.

RESULTS

Robotic colorectal surgery is oncologically safe and has short-term outcomes comparable to conventional laparoscopy, with potential benefits in rectal surgery. It has a shorter learning curve but increased operative times and costs. It offers potential advantages in the resection of rectal cancer, due to lower conversion rates. There is also a trend toward better outcomes in anastomotic leak rates, circumferential margin positivity, and perseveration of autonomic function.

CONCLUSION

Laparoscopy remains technically challenging and conversion rates are still high. Therefore, most cases of colorectal surgery are still performed open. Robotic surgery aims to overcome the limits of the laparoscopic technique. This new technology has many advantages in terms of articulating instruments, advanced three-dimensional optics, surgeon ergonomics, and improved accessibility to narrow spaces, such as the pelvis. However, further studies are needed to assess long-term results and benefits.

Review and update: robotic transanal surgery (RTAS)

As the field of surgery advances, new approaches have allowed surgeons additional flexibility to perform further interventions with minimal or no external incisions. For many years, single site access (SSA) has been used for transanal procedures, and platforms allowing modified endoscopic approaches have been available. These platforms have limitations related to access, visualization, dexterity, camera control, and instrumentation. Recently, surgical robotics companies have developed and introduced new technologies and platforms, which may help address some of these limitations. Comprehensive internet, open access, and medical and industry conference reviews of robotic surgery platforms and technology available for use in SSA surgery were conducted and 30 articles were found using keywords "robotic surgery, transanal, single site, robotic transanal surgery". A PubMed, Medline, Journals @OVID and open access search for data related to these platforms and technologies was also performed yielding 11 articles. Abstracts were reviewed for those written in the English language, leaving 40 articles which were then filtered for those pertaining to robotic surgery, transanal. 58 abstracts were found, duplicates were eliminated, and the remaining 35 articles were read in their entirety by two reviewers. Several new and existing platforms are identified for use in SSA surgery for transanal surgery as well as abdominal and transoral surgery. These are reviewed, including brand, features, approved and suggested uses, and potential limitations. New robotic technologies serve to enhance the ability of surgeons to perform SSA surgery. This next generation of robotic surgery technology overcomes some of the limitations of preceding endoscopic SSA surgery technology and will enhance the advancement of robotic transanal surgery, but outcomes and performance data are still limited.

Direct target NOTES: prospective applications for next generation robotic platforms

BACKGROUND

A new era in surgical robotics has centered on alternative access to anatomic targets and next generation designs include flexible, single-port systems which follow circuitous rather than straight pathways. Such systems maintain a small footprint and could be utilized for specialized operations based on direct organ target natural orifice transluminal endoscopic surgery (NOTES), of which transanal total mesorectal excision (taTME) is an important derivative.

METHODS

During two sessions, four direct target NOTES operations were conducted on a cadaveric model using a flexible robotic system to demonstrate proof-of-concept of the application of a next generation robotic system to specific types of NOTES operations, all of which required removal of a direct target organ through natural orifice access. These four operations were (a) robotic taTME, (b) robotic transvaginal hysterectomy in conjunction with (c) robotic transvaginal salpingo-oophorectomy, and in an ex vivo model, (d) trans-cecal appendectomy.

RESULTS

Feasibility was demonstrated in all cases using the Flex^® Robotic System with Colorectal Drive. During taTME, the platform excursion was 17 cm along a non-linear path; operative time was 57 min for the transanal portion of the dissection. Robotic transvaginal hysterectomy was successfully completed in 78 min with transvaginal extraction of the uterus, although laparoscopic assistance was required. Robotic transvaginal unilateral salpingo-oophorectomy with transvaginal extraction of the ovary and fallopian tube was performed without laparoscopic assistance in 13.5 min. In an ex vivo model, a robotic trans-cecal appendectomy was also successfully performed for the purpose of demonstrating proof-of-concept only; this was completed in 24 min.

CONCLUSIONS

A flexible robotic system has the potential to access anatomy along circuitous paths, making it a suitable platform for direct target NOTES. The conceptual operations posed could be considered suitable for next generation robotics once the technology is optimized, and after further preclinical validation.

Transanal total mesorectal excision: is it necessary in the era of robots?

Transanal total mesorectal excision (taTME) has been proposed to overcome the limitations of laparoscopic TME. The robotic surgical platform has already established its benefits in providing superior ergonomics, and the purported advantages of taTME may play less important a role in the era of robots.

The da Vinci Xi: a review of its capabilities, versatility, and potential role in robotic colorectal surgery

The Xi is the latest da Vinci surgical system approved for use in colorectal surgery. With its novel overhead architecture, slimmer boom-mounted arms, extended instrument reach, guided targeting, and integrated auxiliary technology, the Xi manages to address several limitations of earlier models. The versatility of this new system allows it to be implemented in a wide range of colorectal procedures - from complex multiquadrant colectomies to challenging mesorectal dissections in the pelvis. While commonly criticized for its cost and prolonged operative time, robotic colorectal surgery holds the potential for enhanced ergonomics, superior precision, and a reduction in the learning curve involved in training an expert surgeon. This review appraises the existing literature on robotic colorectal surgery while elaborating how the improved capabilities of the Xi serve to usher in a new era of minimally invasive colorectal surgery.