Minimally invasive laparoscopy has been the standard in the surgical treatment of endometriosis, including deep-infiltrative lesions of the bowel.(2, 6, 9) However, there are known constraints to standard laparoscopy, which include the loss of three-dimensional visualization, reduced degrees of movement, and the fulcrum effect.(36) The introduction of robotic surgical platforms aimed to address some of these limitations.(36, 37) While meta-analyses(38, 39) established the feasibility of robotic surgery as an alternative to standard laparoscopy for treating endometriosis, none addressed it in the context of bowel DIE. A review by Hur and Falcone(11) had a similar focus, providing a general overview of the role of RALS in bowel endometriosis. However, this present study placed an additional emphasis on conducting a comprehensive review in accordance with the PRISMA guidelines and comparative analysis of data using descriptive statistics.
Choice of surgical techniques using RALS
Significant differences in the choice of surgical techniques emerged between RALS and SLS, with rectal shaves more frequently utilized with RALS (Table 5). The higher prevalence of shaves in the robotic group could be attributed to the benefits associated with robot-assisted surgery, which offers better vision to aid in assessment of disease depth, allowing surgeons to perform complete excisions with clear margins with rectal shaves, and improved dexterity enabling easier and secure suturing within the confines of the pelvis. When more extensive resection is performed, the technical complexities involved may diminish some of the advantages offered by robotic surgery.
Another factor to consider is the inherent variation of surgical indications described in the studies. The choice of technique itself is dependent upon several factors, including the extent and depth of bowel involvement.(6, 9–11). This inherent variability in decision-making reflects the multitude of factors which influence the personalized nature of treatment decisions.
The decision to perform segmental resections balance a lower recurrence risk against the increased risk of major complications, particularly anastamotic leak and requirement for stoma. In the cohort of patients reviewed, 2 anastamotic leaks were identified, both within the RALS group. This could be explained by a number of factors. Sampling bias is likely to have played a significant role in this finding, particularly in the SLS group, where only 35 patients underwent segmental resection. A large multicenter meta-analysis, including 1622 patients puts this risk at 1.9%(40). Comparatively the rate of 0.6% in the RALS group is within acceptable limits. Furthermore, as these cohort studies are unblinded, selection bias may be present, where more complex cases were undertaken when the robotic system is available, as acknowledged by Graham et al(29),.
However, the increased prevalence of segmental resections within the SLS cohort itself introduces a potential confounding variable, given its association with prolonged surgical duration and an increased risk of postoperative complications.(41, 42). These factors can naturally influence other surgical outcomes, such as recovery times and complication rates.
Operative and postoperative outcomes of RALS
This review suggests that RALS is feasible and safe for treating symptomatic patients with bowel deep-infiltrating endometriosis, leading to minimal surgical complications and infrequent conversion to laparotomy. Additionally, there is a trend towards fewer intraoperative complications in the robotic group, although this has not reached clinical significance (Table 5). One study(27) even associates RALS with the preservation of urinary function and sexual well-being up to a year post-surgery. Intraoperative blood loss, another important metric influencing surgical complications, was likewise found to exhibit no significant differences between the groups. The studies included in this review indicate that RALS confers at least an equal benefit in terms of resolution of preoperative symptoms to SLS, but true statistical analysis was not possible due to the heterogeneity of the data.
However, when compared to standard laparoscopy, RALS is associated with significantly longer operating duration, consistent with other reports within the existing literature. Numerous reviews and randomized trials have explored the differences in operating times between RALS and SLS for various subsets of endometriosis patients.(38, 39, 43) While many of these studies reached similar conclusions regarding extended operating times with RALS, there were notable variations in the reported data. Factors contributing to these variations include the selective exclusion of patients with bowel involvement or inclusions of superficial endometriosis in these studies, leading to shorter reported operating times. This complexity underscores the importance of considering specific study contexts and inclusion criteria when interpreting data on operating times.
Postoperatively, the robotic group exhibits a shorter hospital stay and differences in postoperative complication rates, with a slightly higher rate of major complications and a lower rate of minor complications (Table 5). When compared to major laparoscopic studies, with postoperative major complication rates of 2.5% the rate of major complications in this study (4.4% in RALS and 3.6% in SLS) appears high. However, this could be attributable to a smaller sample size (368 and 83 vs 4721)(44). Furthermore, many of these studies acknowledged the learning curve experienced in performing robotic surgery, compared to their significant laparoscopic experience.
In addition, it is important to note that the observational nature of these included studies inherently provides evidence of lower quality compared to RCTs.(45) These studies, due to the lack of controlled interventions, have limitations in their ability to establish causal relationships.
Translation into clinical practice
Prolonged operating time can largely be attributed to the unique characteristics of robotic surgery, with additional time required for tasks such as docking, robot positioning, and troubleshooting technical issues.(11, 36) Previous research(46) describing surgical treatments of advanced endometriosis had shown that longer durations of surgery potentially increase the physiological stress on the patient, adversely affecting recovery times and postoperative outcomes.
Another factor to consider is that operating room time is a valuable resource in healthcare. Prolonged surgeries consume more resources, including personnel, equipment, and facilities – on top of the costs incurred for implementing and maintaining the robotic equipment.(47) Consequently, this can result in higher immediate costs, which may be offset by the significantly shorter length of stay and lower rates of surgical complications. Furthermore, as the use of the robotic systems mature, it is expected that the operating time will decrease as the learning curve is overcome by both the surgeons and their supporting theatre staff.
In summary, from a practical perspective, the availability of a robotic system can pose a barrier to the adoption of RALS due to its high start-up costs. Nevertheless, as demonstrated in this review, there are potential benefits to using RALS which can only be fully understood through increased availability and utilization of robotic operating systems within the healthcare system. It is important to note that comprehensive cost-benefit analyses specific to RALS in treating bowel DIE have been lacking thus far. Future research is essential to provide additional perspectives on the medico-economic implications associated with RALS.
IDEAL staging of RALS for bowel DIE
The evaluation of RALS for the treatment of bowel DIE reveals a dynamic landscape of evolving surgical techniques and research methodologies as evidenced by the studies highlighted in this review. In the early 2010s, studies(21, 22, 24, 25) on this topic predominantly featured single-centre retrospective case series, indicative of the IDEAL Stage 2a (Development).(16) These studies sought to establish the viability and safety of RALS for bowel DIE, along with building consensus on the technical aspects of the procedure and sharing early clinical experiences.
However, recent papers(30, 31) on the technique have transitioned into Stage 2b (Exploration), characterized by prospective cohort studies. This evolution reflects the maturity of the technique, supported by robust findings indicating its feasibility and safety. Studies directly comparing RALS against standard laparoscopy are emerging, shedding light on the learning curves associated with RALS and highlighting the necessity for RCTs to provide more definitive evidence. Based on these considerations, the overall staging of RALS for bowel DIE can be classified as the endpoint of Stage 2b. This signifies a consensus on the maturity of the technique, favourable clinical outcomes, and an understanding of desirable outcome measures.(16)
Looking ahead, it is imperative that multicentre RCTs be undertaken to provide higher-quality evidence to investigate the comparative effectiveness of RALS versus SLS. Notably, the upcoming ROBEndo RCT(48) represents a promising step in this direction and holds the potential to influence future research in this field.
Limitations
It is important to recognize that like any literature review, this analysis may be susceptible to evidence selection, reporting, and publication biases, as well as the inherent biases of the studies previously mentioned.(49) To limit the sources of these biases, several measures were put in place. Firstly, two independent reviewers performed a thorough assessment of the methodology and risk of bias in all the studies (Tables 6 and 7). Additionally, strict adherence to PRISMA guidelines ensured a structured review and reporting process.
Table 6
JBI checklist for case series(17)
| Ercoli et al.20 | Cassini et al.21 | Collinet et al.22 | Siesto et al.23 | Diguisto et al.24 | Pellegrino et al.25 | Morelli et al.26 | Abo et al.27 | Graham et al. 28 |
Were there clear criteria for inclusion in the case series? | Y | Y | Y | Y | Y | Y | Y | Y | Y |
Was the condition measured in a standard, reliable way for all participants included in the case series? | Y | Y | Y | Y | Y | Y | Y | Y | Y |
Were valid methods used for identification of the condition for all participants included in the case series? | Y | Y | Y | Y | Y | Y | Y | Y | Y |
Did the case series have consecutive inclusion of participants? | Y | Y | Unk. | Y | Y | Y | Y | Y | Y |
Did the case series have complete inclusion of participants? | Y | Y | Unk. | Y | Y | Y | Y | Y | Y |
Was there clear reporting of the demographics of the participants in the study? | Y | Y | Y | Y | Y | Y | Y | Y | Y |
Was there clear reporting of clinical information of the participants? | Y | Y | Y | Y | Y | Y | Y | Y | Y |
Were the outcomes or follow up results of cases clearly reported? | Y | Y | Y | Y | Y | Y | Y | Y | Y |
Was there clear reporting of the presenting site(s)/clinic(s) demographic information? | N | N | N | N | N | N | N | N | N |
Was statistical analysis appropriate? | Y | Y | Y | Y | Y | Y | Y | Y | Y |
Y: Yes; N: No; N/A: Not applicable to study; Unk: Unknown |
Table 7
JBI checklist for cohort studies(18)
| Raimondo et al.29 | Ferrier et al.30 |
Were the two groups similar and recruited from the same population? | Y | Y |
Were the exposures measured similarly to assign people to both exposed and unexposed groups? | Y | Y |
Was the exposure measured in a valid and reliable way? | Y | Y |
Were the confounding factors identified? | Y | Y |
Were strategies to deal with confounding factors stated? | Y | Y |
Were the groups/participants free of the outcome at the start of the study (or at the moment of exposure)? | N/A | N/A |
Were the outcomes measured in a valid and reliable way? | Y | Y |
Was the follow up time reported and sufficient to be long enough for outcomes to occur? | Y | Y |
Was follow up complete, and if not, were the reasons to loss to follow up described and explored? | Y | Y |
Were strategies to address incomplete follow up utilized? | N/A | N/A |
Was appropriate statistical analysis used? | Y | Y |
Y: Yes; N: No; N/A: Not applicable to study |
However, the nature of the included studies inherently provides lower-quality evidence compared to prospective RCTs.(45) While these studies offer valuable insights into real-world clinical practices, the observational nature and lack of controlled interventions limit their ability to establish definitive causal relationships. Furthermore, their vulnerability to confounders presents a concern, given that this review cannot address all potential factors that might influence the outcomes, such as the surgeons’ learning curve for RALS. Lastly, heterogeneity in outcome reporting measures, alongside the lack of studies reporting relevant outcomes such as urinary and sexual function, cost analysis, and fertility, prevents a more comprehensive assessment from being performed.