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Year : 2021  |  Volume : 17  |  Issue : 2  |  Page : 278

Rate of conversion to an open procedure: Is it really reduced in robotic colorectal surgery?

Department of Surgery and Anatomy, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil

Date of Submission21-Jul-2020
Date of Acceptance04-Sep-2020
Date of Web Publication11-Nov-2020

Correspondence Address:
Dr. Rogério Serafim Parra
Av. Bandeirantes, 3900, Zip Code: 14048-900, City of Ribeirao Preto, State of Sao Paulo
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jmas.JMAS_136_20

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How to cite this article:
Parra RS, Feitosa MR, Féres O. Rate of conversion to an open procedure: Is it really reduced in robotic colorectal surgery?. J Min Access Surg 2021;17:278

How to cite this URL:
Parra RS, Feitosa MR, Féres O. Rate of conversion to an open procedure: Is it really reduced in robotic colorectal surgery?. J Min Access Surg [serial online] 2021 [cited 2021 Dec 6];17:278. Available from:

Dear Sir,

Wells et al.[1] recently published a single-institution retrospective cohort study with 235 patients undergoing laparoscopic or robotic procedures for dysplastic or neoplastic disease. The authors concluded that robotic surgery may offer low rates of conversion to an open procedure, resulting in lower post-operative complications, earlier return of function and reduced narcotic use. Despite the relevant information described in the study, some important issues need to be discussed.

The comparison was made between heterogeneous groups. Despite the similarity in gender and race distributions, the mean age and the Charlson Comorbidity Index were different between groups. In addition, they showed that tumour location differed between the two groups: In the laparoscopic group, there was a predominance of right-sided tumours, while in the robotic group, rectal or left-sided colon lesions were more prevalent.

Based on the different characteristics between the two groups, it is not possible to state that robotic surgery for dysplastic or neoplastic disease is associated with lower conversion rates compared to laparoscopy. The two groups should have been compared using a propensity score matching (PSM) analysis. Previous studies have addressed this matter using the PSM analysis to reduce selection bias.[2] Still, a randomised controlled trial (RCT) remains the best study design to evaluate and compare treatments. The lack of published RCTs comparing laparoscopic with robotic surgery represents a major limitation in the operative management of colorectal tumours. The PSM analysis has been developed as an alternative to RCTs in order to provide higher level of evidence.[3]

As described by the authors, selection bias played an important role in the current study. To adjust and optimise the matching procedure, the authors should have performed a PSM to understand if robotic surgery is really associated with reduction in the conversion rates.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Wells LE, Smith B, Honaker MD. Rate of conversion to an open procedure is reduced in patients undergoing robotic colorectal surgery: A single-institution experience. J Minim Access Surg 2020;16:229-34.  Back to cited text no. 1
Kim HJ, Choi GS, Park JS, Park SY, Yang CS, Lee HJ. The impact of robotic surgery on quality of life, urinary and sexual function following total mesorectal excision for rectal cancer: A propensity score-matched analysis with laparoscopic surgery. Colorectal Dis 2018;20:O103-13.  Back to cited text no. 2
Kuss O, Blettner M, Börgermann J. Propensity Score: An Alternative Method of Analyzing Treatment Effects. Dtsch Arztebl Int 2016;113:597-603.  Back to cited text no. 3


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2004 Journal of Minimal Access Surgery
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