Robot-assisted intersphincteric resection facilitates an efficient sphincter-saving in patients with low rectal cancer

Propensity matched analysis of minimally invasive and open radical resection for rectal cancer: comparison of short-term outcomes in elderly/frail patients

Although minimally invasive surgery (MIS), such as robotic and laparoscopic procedures, is sometimes a better option than open surgery for patients with rectal cancer, it can present challenges for some elderly or frail patients who have a higher risk of chronic illnesses and poor surgical tolerance. On the basis of several pathophysiological characteristics, the patients were grouped according to their age. The time nodes, which are 65 and 80 years old, can clarify the goal of the study and offer some therapeutic benefit. These subgroups stand to gain a great deal from MIS because of its superior arm of machinery and imagery. The short-term oncological outcomes and postoperative conditions of robotic surgery, laparoscopic surgery, and conventional open surgery were compared in this study using a propensity-matched analysis. In this retrospective study, a total of 2049 consecutive patients who underwent proctectomy between September 2017 and June 2023 were chosen. We then carried out a propensity matching analysis based on inclusion criteria. Patients were split into two age groups: 65-80 and  > 80. While the secondary objective was to further investigate the similar characteristics between RS and LS, the major objective was to compare oncological outcomes and postoperative conditions between MIS and OS. K-M survival curves were used to represent oncological outcomes and survival conditions. Complication rate and mFI score were used to assess postoperative conditions. Regarding the functional outcomes, the LARS scale was applied to create questionnaires that calculated the anal function of the patients. 110 cases from the group of patients aged 65-80 were successfully merged after matching 1: 1 by propensity score, whereas 73 instances from patients aged > 80 were incorporated while examining the primary objective between OS and MIS. Regarding the secondary goal, each group contained 45 cases for patients above 80 and 65 cases for patients aged 65-80, respectively. Faster recovery from MIS included quicker first flatus passage, earlier switch to liquid nutrition, and shorter hospital stay. In the meantime, MIS also showed benefits in terms of the proportion of low mFI scores and the rates of wound complications in the two age groups. Less blood loss and shorter operational time are further MIS features. On the other hand, MIS experienced more pulmonary complications than OS. Robotic surgery was statistically no different from laparoscopic surgery in patients aged 65-80, although it was superior in terms of operative time and recovery. Comparable and satisfactory oncological and survival results were obtained with all three treatments. For elderly/frail patients with rectal cancer, MIS could be recognized as an effective procedure with favorable outcomes of recovery that are accompanied by better postoperative conditions. While, robotic surgery is slightly better than laparoscopic surgery in some aspects. However, to further demonstrate the effectiveness of three surgical modalities in treating certain groups, multi-center prospective studies are required.

International standardization and optimization group for intersphincteric resection (ISOG-ISR): modified Delphi consensus on anatomy, definition, indication, surgical technique, specimen description and functional outcome

AIM

Intersphincteric resection (ISR) is an oncologically complex operation for very low-lying rectal cancers. Yet, definition, anatomical description, operative indications and operative approaches to ISR are not standardized. The aim of this study was to standardize the definition of ISR by reaching international consensus from the experts in the field. This standardization will allow meaningful comparison in the literature in the future.

METHOD

A modified Delphi approach with three rounds of questionnaire was adopted. A total of 29 international experts from 11 countries were recruited for this study. Six domains with a total of 37 statements were examined, including anatomical definition; definition of intersphincteric dissection, intersphincteric resection (ISR) and ultra-low anterior resection (uLAR); indication for ISR; surgical technique of ISR; specimen description of ISR; and functional outcome assessment protocol.

RESULTS

Three rounds of questionnaire were performed (response rate 100%, 89.6%, 89.6%). Agreement (≥80%) reached standardization on 36 statements.

CONCLUSION

This study provides an international expert consensus-based definition and standardization of ISR. This is the first study standardizing terminology and definition of deep pelvis/anal canal anatomy from a surgical point of view. Intersphincteric dissection, ISR and uLAR were specifically defined for precise surgical description. Indication for ISR was determined by the rectal tumour's maximal radial infiltration (T stage) below the levator ani. A new surgical definition of T3isp was reached by consensus to define T3 low rectal tumours infiltrating the intersphincteric plane. A practical flowchart for surgical indication for uLAR/ISR/abdominoperineal resection was developed. A standardized ISR surgical technique and functional outcome assessment protocol was defined.

Propensity score-matched analysis of the short-term outcomes of robotic versus laparoscopic surgery for rectal cancer

PURPOSE

The advantages of robot-assisted rectal surgery (RARS) over conventional laparoscope-assisted rectal surgery (LARS) remain controversial. This study was performed to compare the short-term outcomes of RARS and LARS.

METHODS

We retrospectively analyzed data of 207 patients who had undergone either RARS (n = 97) or LARS (n = 110) for rectal cancer (RC) from 2018 to 2020. A 1:1 matched propensity score-matched analysis was performed and the surgical outcomes of the two groups compared.

RESULTS

After matching, a well-balanced cohort of 136 patients was analyzed (n = 68 in each group), and there was no significant difference in the median operative time. The RARS group had less intraoperative blood loss than the LARS group. There were no significant differences in length of postoperative hospital stay or complication rate between the two groups. In the subgroup of lower RC, defined as the inferior edge of the tumor being within the rectum distal to the peritoneal reflection, the rate of sphincter preservation was higher in the RARS group (81.8% vs. 44.4%, p = 0.021).

CONCLUSION

This study shows that RARS is a safe and feasible approach for RC compared with LARS, RARS having the advantage of more often preserving the sphincter.

Robotic versus laparoscopic surgery for middle and low rectal cancer (REAL): short-term outcomes of a multicentre randomised controlled trial

BACKGROUND

Robotic surgery for rectal cancer is gaining popularity, but evidence on long-term oncological outcomes is scarce. We aimed to compare surgical quality and long-term oncological outcomes of robotic and conventional laparoscopic surgery in patients with middle and low rectal cancer. Here we report the short-term outcomes of this trial.

METHODS

This multicentre, randomised, controlled, superiority trial was done at 11 hospitals in eight provinces of China. Eligible patients were aged 18-80 years with middle (>5 to 10 cm from the anal verge) or low (≤5 cm from the anal verge) rectal adenocarcinoma, cT1-T3 N0-N1 or ycT1-T3 Nx, and no evidence of distant metastasis. Central randomisation was done by use of an online system and was stratified according to participating centre, sex, BMI, tumour location, and preoperative chemoradiotherapy. Patients were randomly assigned at a 1:1 ratio to receive robotic or conventional laparoscopic surgery. All surgical procedures complied with the principles of total mesorectal excision or partial mesorectal excision (for tumours located higher in the rectum). Lymph nodes at the origin of the inferior mesenteric artery were dissected. In the robotic group, the excision procedures and dissection of lymph nodes were done by use of robotic techniques. Neither investigators nor patients were masked to the treatment allocation but the assessment of pathological outcomes was masked to the treatment allocation. The primary endpoint was 3-year locoregional recurrence rate, but the data for this endpoint are not yet mature. Secondary short-term endpoints are reported in this article, including two key secondary endpoints: circumferential resection margin positivity and 30-day postoperative complications (Clavien-Dindo classification grade II or higher). The outcomes were analysed according in a modified intention-to-treat population (according to the original assigned groups and excluding patients who did not undergo surgery or no longer met inclusion criteria after randomisation). This trial was registered with ClinicalTrials.gov, number NCT02817126. Study recruitment has completed, and the follow-up is ongoing.

FINDINGS

Between July 17, 2016, and Dec 21, 2020, 1742 patients were assessed for eligibility. 502 patients were excluded, and 1240 patients were enrolled and randomly assigned to receive either robotic surgery (620 patients) or laparoscopic surgery (620 patients). 69 patients were excluded (34 in the robotic surgery group and 35 in the laparoscopic surgery group). 1171 patients were included in the modified intention-to-treat analysis (586 in the robotic group and 585 in the laparoscopic group). Six patients in the robotic surgery group received laparoscopic surgery and seven patients in the laparoscopic surgery group received robotic surgery. 22 (4·0%) of 547 patients in the robotic group had a positive circumferential resection margin as did 39 (7·2%) of 543 patients in the laparoscopic group (difference -3·2 percentage points [95% CI -6·0 to -0·4]; p=0·023). 95 (16·2%) of patients in the robotic group had at least one postoperative complication (Clavien-Dindo grade II or higher) within 30 days after surgery, as did 135 (23·1%) of 585 patients in the laparoscopic group (difference -6·9 percentage points [-11·4 to -2·3]; p=0·003). More patients in the robotic group had a macroscopic complete resection than in the laparoscopic group (559 [95·4%] of 586 patients vs 537 [91·8%] of 585 patients, difference 3·6 percentage points [0·8 to 6·5]). Patients in the robotic group had better postoperative gastrointestinal recovery, shorter postoperative hospital stay (median 7·0 days [IQR 7·0 to 11·0] vs 8·0 days [7·0 to 12·0], difference -1·0 [95% CI -1·0 to 0·0]; p=0·0001), fewer abdominoperineal resections (99 [16·9%] of 586 patients vs 133 [22·7%] of 585 patients, difference -5·8 percentage points [-10·4 to -1·3]), fewer conversions to open surgery (10 [1·7%] of 586 patients vs 23 [3·9%] of 585 patients, difference -2·2 percentage points [-4·3 to -0·4]; p=0·021), less estimated blood loss (median 40·0 mL [IQR 30·0 to 100·0] vs 50·0 mL [40·0 to 100·0], difference -10·0 [-20·0 to -10·0]; p<0·0001), and fewer intraoperative complications (32 [5·5%] of 586 patients vs 51 [8·7%] of 585 patients; difference -3·3 percentage points [-6·3 to -0·3]; p=0·030) than patients in the laparoscopic group.

INTERPRETATION

Secondary short-term outcomes suggest that for middle and low rectal cancer, robotic surgery resulted in better oncological quality of resection than conventional laparoscopic surgery, with less surgical trauma, and better postoperative recovery.

FUNDING

Shenkang Hospital Development Center, Shanghai Municipal Health Commission (Shanghai, China), and Zhongshan Hospital Fudan University (Shanghai, China).

Surgical Treatment of Low-Lying Rectal Cancer: Updates

Despite innovative advancements, distally located rectal cancer remains a critical disease of challenging management. The crucial location of the tumor predisposes it to a circumferential resection margin (CRM) that tends to involve the anal sphincter complex and surrounding organs, with a high incidence of delayed anastomotic complications and the risk of the pelvic sidewall or rarely inguinal lymph node metastases. In this regard, colorectal surgeons should be aware of other issues beyond total mesorectal excision (TME) performance. For decades, the concept of extralevator abdominoperineal resection to avoid compromised CRM has been introduced. However, the complexity of deep pelvic dissection with poor visualization in low-lying rectal cancer has led to transanal TME. In contrast, neoadjuvant chemoradiotherapy (NCRT) has allowed for the execution of more sphincter-saving procedures without oncologic compromise. Significant tumor regression after NCRT and complete pathologic response also permit applying the watch-and-wait protocol in some cases, now with more solid evidence. This review article will introduce the current surgical treatment options, their indication and technical details, and recent oncologic and functional outcomes. Lastly, the novel characteristics of distal rectal cancer, such as pelvic sidewall and inguinal lymph node metastases, will be discussed along with its tailored and individualized treatment approach.

Robotic Intersphincteric Resection for Low Rectal Cancer: Technical Controversies and a Systematic Review on the Perioperative, Oncological, and Functional Outcomes

Intersphincteric resection (ISR) is the ultimate anus-sparing technique for low rectal cancer and is considered an oncologically safe alternative to abdominoperineal resection. The application of the robotic approach to ISR (RISR) has been described by few specialized surgical teams with several differences regarding approach and technique. This review aims to discuss the technical aspects of RISR by evaluating point by point each surgical controversy. Moreover, a systematic review was performed to report the perioperative, oncological, and functional outcomes of RISR. Postoperative morbidities after RISR are acceptable. RISR allows adequate surgical margins and adequate oncological outcomes. RISR may result in severe bowel and genitourinary dysfunction affecting the quality of life in a portion of patients.

Anus-Preserving Surgery in Advanced Low-Lying Rectal Cancer: A Perspective on Oncological Safety of Intersphincteric Resection

The surgical management of low-lying rectal cancer, within 5 cm from the anal verge (AV), is challenging due to the possibility, or not, to preserve the anus with its sphincter muscles maintaining oncological safety. The standardization of total mesorectal excision, the adoption of neoadjuvant chemoradiotherapy, the implementation of rectal magnetic resonance imaging, and the evolution of mechanical staplers have increased the rate of anus-preserving surgeries. Moreover, extensive anatomy and physiology studies have increased the understanding of the complexity of the deep pelvis. Intersphincteric resection (ISR) was introduced nearly three decades ago as the ultimate anus-preserving surgery. The definition and indication of ISR have changed over time. The adoption of the robotic platform provides excellent perioperative results with no differences in oncological outcomes. Pushing the boundaries of anus-preserving surgeries has risen doubts on oncological safety in order to preserve function. This review critically discusses the oncological safety of ISR by evaluating the anatomical characteristics of the deep pelvis, the clinical indications, the role of distal and circumferential resection margins, the role of the neoadjuvant chemoradiotherapy, the outcomes between surgical approaches (open, laparoscopic, and robotic), the comparison with abdominoperineal resection, the risk factors for oncological outcomes and local recurrence, the patterns of local recurrences after ISR, considerations on functional outcomes after ISR, and learning curve and surgical education on ISR.

Short-term outcomes of robotic-assisted versus conventional laparoscopic-assisted surgery for rectal cancer: a propensity score-matched analysis

It remains controversial whether the advantages of robotic-assisted surgery are beneficial for rectal cancer (RC). The study aimed to evaluate the short-term outcomes of robotic-assisted rectal surgery (RARS) compared with those of conventional laparoscopic-assisted rectal surgery. We retrospectively analyzed 539 consecutive patients with stage I-IV RC who had undergone elective surgery between January 2010 and December 2020, using propensity score-matched analysis. After propensity score matching, we enrolled 200 patients (n = 100 in each groups). Before matching, significant group-dependent differences were observed in terms of age (p = 0.04) and body mass index (p < 0.01). After matching, clinicopathologic outcomes were similar between the groups, but estimated operative time was longer and postoperative lymphorrhea was more frequent in the RARS group. Estimated blood loss, rate of conversion to laparotomy, and incidence of anastomotic leakage or reoperation were significantly lower in the RARS group. No surgical mortality was observed in either group. No significant differences were observed in terms of positive resection margins or number of lymph nodes harvested. RARS was safe and technically feasible, and achieved acceptable short-term outcomes. The robotic technique showed some advantages in RC surgery that require validation in further studies.

Complete intersphincteric longitudinal muscle excision May Be key to reducing local recurrence during intersphincteric resection

BACKGROUND

Although total mesorectal excision (TME) is regarded as a standard procedure for rectal cancer, technical definition and evaluation method have not yet been investigated for intersphincteric resection (ISR). This study was performed to introduce a complete ISR procedure, and to assess whether total intersphincteric longitudinal muscle excision (TILME) facilitated the completeness of ISR and reduced recurrence.

METHODS

A total of 1080 patients with rectal adenocarcinoma who underwent robot-assisted low anterior resection (LAR) over 10 years were consecutively enrolled. Propensity-score matching of the two LAR groups (ISR vs LAR group, 1:1) and three ISR subgroups (partial vs subtotal vs total ISR subgroup, 2:2:1) was performed by strict adjustment of baseline characteristics. Archived specimens and video-/photo-records were reevaluated to examine completeness of TILME.

RESULTS

Complete-TILME was performed in 84.5% of patients who underwent ISR. Multivariate analysis showed that incomplete-TILME was the only parameter independently associated with increased 5-year cumulative local recurrence (odds ratio = 23.385; 95% confidence interval = 1.492-366.421; p = 0.03), and that incomplete-TILME was independently associated with adipose tissue surrounding the intersphincteric longitudinal muscle, coloanal anastomosis, and total ISR (p < 0.001-0.05). Although mean incontinence scores and anorectal manometry deteriorated to some degree 12-24 months after surgery in all patients, they remained acceptable. The 5-year cumulative DFS (74.1% vs 60%, p = 0.18) and OS (85.9% vs 70%, p = 0.10) rates tended to be higher in patients with complete than incomplete-TILME.

CONCLUSIONS

The completeness of TILME appears to be an independent indicator of complete ISR, reducing local recurrence following lower rectal cancer surgery.

Robotic Total Mesorectal Excision for Rectal Cancer: Current Evidences and Future Perspectives

Despite the technical limitations of minimally invasive surgery, laparoscopic total mesorectal excision (LTME) for rectal cancer has short-term advantages over open surgery, but the pathological outcomes reported in randomized clinical trials are still in controversy. Minimally invasive robotic total mesorectal excision (RTME) has recently been gaining popularity as robotic surgical systems potentially provide greater benefits than LTME. Compared to LTME, RTME is associated with lower conversion rates and similar or better genitourinary functions, but its long-term oncological outcomes have not been established. Although the operating time of RTME is longer than that of LTME, RTME has a shorter learning curve, is more convenient for surgeons, and is better for sphincter-preserving operations than LTME. The robotic surgical system is a good technical tool for minimally invasive surgery for rectal cancer, especially in male patients with narrow deep pelvises. Robotic systems and robotic surgical techniques are still improving, and the contribution of RTME to the treatment of rectal cancer will continue to increase in the future.

Robotic Surgery for Rectal Cancer: Hype or Hope? (Indian Experience)

The primary goal to achieve cure in oncology is to reduce recurrence, maximize disease-free survival, maintain function, and optimize quality of life. Surgery remains the mainstay treatment modality in rectal cancer. The current trend is to perform least invasive method of doing complex surgeries while not compromising in the oncological of functional outcomes of patients. Total mesorectal excision (TME) for rectal cancer surgery entails removal of the rectum with its fascia as an intact unit while preserving surrounding vital structures. The procedure is technically challenging because of the narrow and deep pelvic cavity housing the rectum encased by fatty lymph vascular tissue within the perirectal fascia, distally the anal sphincter complex, and an intimate surrounded by vital structures like ureter, vessels, and nerves. Robotic technology enables overcoming these difficulties caused by complex pelvic anatomy. This system can facilitate better preservation of the pelvic autonomic nerve and thereby achieve favorable postoperative sexual and voiding functions after rectal cancer surgery. The nerve-preserving TME technique includes identification and preservation of the superior hypogastric plexus nerve, bilateral hypogastric nerves, pelvic plexus, and neurovascular bundles.

Robotic Surgery for Rectal Cancer and Cost-Effectiveness

Robotic surgery is considered as one of the advanced treatment modality of minimally invasive surgery for rectal cancer. Robotic rectal surgery has been performed for three decades and its application is gradually expanding along with technology development. It has several technical advantages which include magnified three-dimensional vision, better ergonomics, multiple articulated robotic instruments, and the opportunity to perform remote surgery. The technical benefits of robotic system can help to manipulate more meticulously during technical challenging procedures including total mesorectal excision in narrow pelvis, lateral pelvic node dissection, and intersphincteric resection. It is also reported that robotic rectal surgery have been shown more favorable postoperative functional outcomes. Despite its technical benefits, a majority of studies have been reported that there is rarely clinical or oncologic superiority of robotic surgery for rectal cancer compared to conventional laparoscopic surgery. In addition, robotic rectal surgery showed significantly higher costs than the standard method. Hence, the cost-effectiveness of robotic rectal surgery is still questionable. In order for robotic rectal surgery to further develop in the field of minimally invasive surgery, there should be an obvious cost-effective advantages over laparoscopic surgery, and it is crucial that large-scale prospective randomized trials are required. Positive competition of industries in correlation with technological development may gradually reduce the price of the robotic system, and it will be helpful to increase the cost-effectiveness of robotic rectal surgery.

Robotic-assisted surgery for rectal cancer: Current state and future perspective

Interest in minimally invasive surgery has increased in recent decades. Robotic-assisted laparoscopic surgery (RALS) was introduced as the latest advance in minimally invasive surgery. RALS has the potential to provide better clinical outcomes in rectal cancer surgery, allowing for precise dissection in the narrow pelvic space. In addition, RALS represents an important advancement in surgical education with respect to use of the dual-console robotic surgery system. Because the public health insurance systems in Japan have covered the cost of RALS for rectal cancer since April 2018, RALS has been attracting increasingly more attention. Although no overall robust evidence has yet shown that RALS is superior to laparoscopic or open surgery, the current evidence supports the notion that technically demanding subgroups (patients with obesity, male patients, and patients treated by extended procedures) may benefit from RALS. Technological innovation is a constantly evolving field. Several companies have been developing new robotic systems that incorporate new technology. This competition among companies in the development of such systems is anticipated to lead to further improvements in patient outcomes as well as drive down the cost of RALS, which is one main concern of this new technique.

Critical and Challenging Issues in the Surgical Management of Low-Lying Rectal Cancer

Despite innovative advancements, the management of distally located rectal cancer (RC) remains a formidable endeavor. The critical location of the tumor predisposes it to a circumferential resection margin that tends to involve the sphincters and surrounding organs, pelvic lymph node metastasis, and anastomotic complications. In this regard, colorectal surgeons should be aware of issues beyond the performance of total mesorectal excision (TME). For decades, abdominoperineal resection had been the standard of care for low-lying RC; however, its association with high rates of tumor recurrence, tumor perforation, and poorer survival has stimulated the development of novel surgical techniques and modifications, such as extralevator abdominoperineal excision. Similarly, difficult dissections and poor visualization, especially in obese patients with low-lying tumors, have led to the development of transanal TME or the "bottom-to-up" approach. Additionally, while neoadjuvant chemoradiotherapy has allowed for the execution of more sphincter-saving procedures without oncologic compromise, functional outcomes remain an issue. Nevertheless, neoadjuvant treatment can lead to significant tumor regression and complete pathological response, permitting the utilization of organ-preserving strategies. At present, an East and West dualism pervades the management of lateral lymph node metastasis, thereby calling for a more global and united approach. Moreover, with the increasing importance of quality of life, a tailored, individualized treatment approach is of utmost importance when taking into account oncologic and anticipated functional outcomes.

Functional outcomes after intersphincteric resection for ultralow rectal cancer

Anal function is one of the most important parameters for evaluating the efficacy of intersphincteric resection (ISR) for the treatment of ultralow rectal cancer (< 1 cm from the anal sphincter). Although there have been no results hitherto from randomized controlled trials to verify the clinical benefits of the ultimate sphincter-sparing technique, increasing evidence demonstrates that ISR significantly decreases the rate of permanent stoma and patients could acquire satisfied functional results after surgery. This review discusses the short-term and long-term functional outcomes, risk factors for anal incontinence, and surgical method and approach of ISR.