The effect of proctoring on the learning curve of transanal minimally invasive surgery for local excision of rectal neoplasms
The current method of choice for local resection of benign and selected malignant rectal tumors is transanal endoscopic microsurgery. Transanal minimally invasive surgery (TAMIS) yields similar oncological results and better patient reported outcomes when compared to transanal endoscopic micro surgery. However, due to the technical complexity of TAMIS, a significant learning curve has been suggested. Data on the surgical learning curve are limited. The aim of our study was to investigate surgeon specific learning curves for TAMIS procedures for the local excision of selected rectal tumors, and analyze the effects of proctoring on operating time and outcome.
The current study was prospective of all TAMIS procedures performed by two surgeons from October 2010 to November 2017. Margin positivity, specimen fragmentation, adverse events and operative time were evaluated with a cumulative sum analysis to determine the number of procedures required to reach proficiency. Cumulative sum (CUSUM) analysis was used to determine trends in changes over time.
The earliest adopter, surgeon A, performed 103 procedures, was not proctored and developed the standardized institutional program. Surgeon B, performed 26 cases, had the benefit of a proctorship and availability of a standardized program. The CUSUM curve for operative time showed a change after 36 cases for surgeon A and after 10 cases for surgeon B. For margin positivity proficiency was reached after 31 and 6 cases for surgeon A and B, respectively. The complications curve for surgeon A showed a three-phase learning curve with a decrease after the 26th case whereas surgeon B only had one (3.8%) complication in the learning phase with no change point in the CUSUM curve. Comparing pre- and post-proficiency periods there was a decrease in operating time for both surgeon A (84.4 ± 47.3 to 55.9 ± 30.1 min) and surgeon B (90.6 ± 64.to 53 ± 26.5 min; p < 0.001). Overall margin positivity rates decreased non significantly from 21.7 to 4.8% (p = 0.23). Complications were higher in the pre-proficiency period (21.7% vs. 13.0%; p = 0.02). Surgeon A had significantly more postoperative complications in pre-proficiency phase when compared to surgeon B (25% vs. none, p < 0.001), in the post-proficiency phase there was no statistically significant difference between both surgeons (p = 0.08).
Our results suggest that to reach satisfactory results for TAMIS, 18–31 procedures are required. Standardized institutional operative protocols together with proficient proctorship may contribute to a shorter learning curve with fewer cases (6–10) required to reach proficiency.
KeywordsTAMIS Transanal minimally invasive surgery Learning curve TEMS Rectal cancer
The research for this manuscript was not financially supported and none of the authors had any relevant financial relationships.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
Approval of the institutional review board or ethics committee was not required because of the retrospective and observational character of this study.
For this type of study formal consent is not required.
- 11.Lee L, Burke JP, deBeche-Adams T, Nassif G, Martin-Perez B, Monson JR, Albert MR, Atallah SB (2017) Transanal minimally invasive surgery for local excision of benign and malignant rectal neoplasia: outcomes from 200 consecutive cases with midterm follow up. Ann Surg. https://doi.org/10.1097/SLA.0000000000002190 CrossRefPubMedPubMedCentralGoogle Scholar
- 12.Clermonts S, van Loon YT, Schiphorst AHW, Wasowicz DK, Zimmerman DDE (2017) Transanal minimally invasive surgery for rectal polyps and selected malignant tumors: caution concerning intermediate-term functional results. Int J Colorectal Dis 32(12):1677–1685. https://doi.org/10.1007/s00384-017-2893-6 CrossRefPubMedGoogle Scholar
- 14.Lee L, Kelly J, Nassif GJ, Keller D, Debeche-Adams TC, Mancuso PA, Monson JR, Albert MR, Atallah SB (2017) Establishing the learning curve of transanal minimally invasive surgery for local excision of rectal neoplasms. Surg Endosc. https://doi.org/10.1007/s00464-017-5817-1 CrossRefPubMedPubMedCentralGoogle Scholar
- 15.Clermonts S, Brokelman DL,W, Zijlstra W, Maring J, Wasowicz D. Zimmerman D (2015) Transanal minimally invasive surgery; a multicentre assessment of feasibility, safety and 2-phase learning process comparison Are safety or learning curve influenced by the (in) ability to use TEMS-equipment as emergency-backup during TAMIS? In: Poster abstract ESCP 10th scientific and annual meeting. Dublin 2015Google Scholar
- 16.Han Y, He YG, Lin MB, Zhang YJ, Lu Y, Jin X, Li JW (2012) Local resection for rectal tumors: comparative study of transanal endoscopic microsurgery vs. conventional transanal excision—the experience in China. Hepatogastroenterology 59(120):2490–2493. https://doi.org/10.5754/hge12135 CrossRefPubMedGoogle Scholar
- 19.Langer C, Liersch T, Suss M, Siemer A, Markus P, Ghadimi BM, Fuzesi L, Becker H (2003) Surgical cure for early rectal carcinoma and large adenoma: transanal endoscopic microsurgery (using ultrasound or electrosurgery) compared to conventional local and radical resection. Int J Colorectal Dis 18(3):222–229. https://doi.org/10.1007/s00384-002-0441-4 CrossRefPubMedGoogle Scholar
- 21.Atkinson S (1994) Applications of statistical process control in health care. Managed Care Quart 2(3):57–69Google Scholar
- 24.Barrie J, Jayne DG, Wright J, Murray CJ, Collinson FJ, Pavitt SH (2014) Attaining surgical competency and its implications in surgical clinical trial design: a systematic review of the learning curve in laparoscopic and robot-assisted laparoscopic colorectal cancer surgery. Ann Surg Oncol 21(3):829–840. https://doi.org/10.1245/s10434-013-3348-0 CrossRefPubMedGoogle Scholar
- 27.Maeda T, Tan KY, Konishi F, Tsujinaka S, Mizokami K, Sasaki J, Kawamura YJ (2010) Accelerated learning curve for colorectal resection, open versus laparoscopic approach, can be attained with expert supervision. Surg Endosc 24(11):2850–2854. https://doi.org/10.1007/s00464-010-1063-5 CrossRefPubMedGoogle Scholar
- 29.Miskovic D, Ni M, Wyles SM, Tekkis P, Hanna GB (2012) Learning curve and case selection in laparoscopic colorectal surgery: systematic review and international multicenter analysis of 4852 cases. Dis Colon Rectum 55(12):1300–1310. https://doi.org/10.1097/DCR.0b013e31826ab4dd CrossRefPubMedGoogle Scholar
- 31.Harrysson IJ, Cook J, Sirimanna P, Feldman LS, Darzi A, Aggarwal R (2014) Systematic review of learning curves for minimally invasive abdominal surgery: a review of the methodology of data collection, depiction of outcomes, and statistical analysis. Ann Surg 260(1):37–45. https://doi.org/10.1097/SLA.0000000000000596 CrossRefPubMedGoogle Scholar