Interpretation
Recently, several studies showed that surgical proficiency and surgical volume seem to play a substantial role in the oncologic outcomes of patients with early-stage cervical cancer treated with a surgical robot, with reported learning curves varying from 19 to 77 cases.9-12 Analysing our own cohort retrospectively, we demonstrated a learning curve of at least 61 procedures during which the survival of patients was inferior to the experienced phase thereafter.8 These nationwide and institutional studies all started their inclusions from the first robot-assisted procedures, soon after the robot was adopted for gynaecological purposes. In the early days of robot-assisted surgery, a structured learning curriculum, as we know it today, did not exist.30 Now that several structured learning curricula for robot-assisted surgery within gynaecological oncology exist31, 32, it is critical to assess its performance in terms of patient outcomes.
Studies in prostate, pancreas and oesophageal cancer already showed that a structured learning curriculum allows for safe introduction of less experienced robotic surgeons without compromising patient outcomes. Their results were mostly based on surgical outcomes such as operation time, blood loss and specimen radicality.33-35Regarding oncological outcomes, several studies performed after the LACC trial suggest it would be safe to continue with minimally invasive surgery when performed by experienced (high-volume) surgeons.36, 37 However, these studies do not specify how the surgeons were trained, other than one study mentioning the surgeons were fellowship-trained.
Importantly, learning curve effects do not merely apply to robot-assisted surgery. In cervical cancer specifically, research showed that surgeons in the early phase of laparoscopic and open radical hysterectomy are also subjected to a learning curve.12Results from studies across the full spectrum of medical specialities and procedures suggest that the learning curve concept applies to adopting many complex surgical procedures, if not all.2, 38-40 Such a learning curve should not be perceived as negative but surgeons need to understand how to limit its effect on patient outcomes while effectively acquiring skills.
In group 3 a lower number of lymph nodes were harvested at pelvic lymph node dissection compared to the other two groups, which could not be explained. No clear consensus exists regarding the relationship between surgical experience and number of lymph nodes harvested.41, 42 The number of lymph nodes removed was not associated with the recurrence rate (non-significant in univariate logistic regression).
Robot-assisted surgery is evolving fast and training programs have a hard time keeping up.43 In previous years, several curricula for robot-assisted gynaecological surgery have been developed, including the SERGS curriculum, which is based on the (so far only) validated curriculum of the European Association of Urology (EAU) Robotic Urologic Section (ERUS).31, 44 The SERGS curriculum follows a validated format30 including didactic training, dry lab, virtual reality simulation, cadaver training, and a stepwise approach of patient training with a minimum of 10 proctored cases.24 Although volume based criteria are not completely abandoned yet, focus is shifted towards competency based criteria. Still, as our results also show, room for further improvement exists since curricula are a crucial step in the standardisation of training and certification of robotic surgeons. Besides curricula development, strategies to assess maintenance of robotic proficiency and to teach the trainers are also needed.45
Quantitative robot-generated performance metrics, so far a rather unused potential in robot learning curricula, could play a crucial role in improving robotic training.46 Incorporating these metrics into a curriculum could be an inexpensive and effective way to quantify skill acquisition. Research on learning curves of conventional laparoscopy trainees already demonstrated that use of force, motion and time metrics could indicate progression of skills over time.47-49 Future areas of research should include validating existing curricula, determining how to translate the acquired skills into patient outcomes (prospectively), and find strategies to assess maintenance of surgical proficiency.

Conclusion

Based on these single-institution results, introducing a novice robotic surgeon who was trained in accordance with a structured curriculum did not significantly compromise surgical or oncological outcomes of early-stage cervical cancer patients treated with robot-assisted surgery. Further research should explore ways to objectively quantify skill acquisition during training and, thereby, minimize the impact of learning curves on patient outcomes.

Acknowledgements

The authors are grateful to R.H.M. Verheijen (emeritus professor Gynaecological Oncology, UMC Utrecht) for his contribution to this study and to the manuscript.

Disclosure of Interests

RPZ is a proctor for robot-assisted surgery in gynaecological oncology on behalf of Intuitive Surgical. All other authors declare they have no conflicts of interests related to the presented research.

Contribution to Authorship

IGTB : Conceptualization, Methodology, Formal analysis, Investigation, Writing – Original Draft, Visualisation. JPH : Conceptualization, Methodology, Validation, Writing – Review & Editing. HWRS : Validation, Writing – Review & Editing.IMJ : Validation, Writing – Review & Editing. CGG : Conceptualization, Methodology, Validation, Writing – Review & Editing. RPZ : Conceptualization, Methodology, Validation, Writing – Review & Editing, Supervision.

Details of Ethics Approval

This study was based on the departmental complication and treatment outcome register for robot-assisted surgery, which is maintained as a part of standard clinical care and primarily aims to improve that care. The institutional review board approved this study and waived individual consent requirements for the use of these pseudonymised retrospective data in accordance to Dutch law. The Medical Research Involving Human Subjects Act (WMO) did not apply to our study and therefore official approval by the Medical Research Ethics Committee was not required under the WMO (MREC number 21-250, date April 7th 2021).

Funding

None.

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