MRI‐based score to predict surgical difficulty in patients with rectal cancer. BJS 2018; 105: 140-146.

Published: 31st October 2017

Authors: L. Escal, S. Nougaret, B. Guiu, M. M. Bertrand, H. de Forges, R. Tetreau et al.

Background

Rectal cancer surgery is technically challenging and depends on many factors. This study evaluated the ability of clinical and anatomical factors to predict surgical difficulty in total mesorectal excision.

Method

Consecutive patients who underwent total mesorectal excision for locally advanced rectal cancer in a laparoscopic, robotic or open procedure after neoadjuvant treatment, between 2005 and 2014, were included in this retrospective study. Preoperative clinical and MRI data were studied to develop a surgical difficulty grade.

Results

In total, 164 patients with a median age of 61 (range 26–86) years were considered to be at low risk (143, 87·2 per cent) or high risk (21, 12·8 per cent) of surgical difficulty. In multivariable analysis, BMI at least 30 kg/m2 (P = 0·021), coloanal anastomosis (versus colorectal) (P = 0·034), intertuberous distance less than 10·1 cm (P = 0·041) and mesorectal fat area exceeding 20·7 cm2 (P = 0·051) were associated with greater surgical difficulty. A four‐item score (ranging from 0 to 4), with each item (BMI, type of surgery, intertuberous distance and mesorectal fat area) scored 0 (absence) or 1 (presence), is proposed. Patients can be considered at high risk of a difficult or challenging operation if they have a score of 3 or more.

Conclusion

This simple morphometric score may assist surgical decision‐making and comparative study by defining operative difficulty before surgery.

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1 Comment

Federico Gheza

1 year ago

Escal et al. (1) used the area of the mesorectum at the level of the fifth sacral vertebra to measure the mesorectal fat. At least two issues need to be considered with this methodology. A single level of measure cannot differentiate between the different types of pelvis i.e. narrow versus wide and that measuring volume of area is probably the preferable method, with a low inter-operator error (2).

Given that the population in this study which included only 12.2% obese patients it doesn’t reflect the distribution in the population in most countries (3) and all values should be normalised for general application. In addition, the authors need to clarify their indications for performing ultra-low anastomoses as the percentage of coloanal-anastomosies performed (54.3%) looks excessively high.

In the score defining surgical difficulties, 3 points on a maximum of 12 were assigned for conversion to an open procedure. Thirteen patients underwent open surgery and surprisingly they were all included in the “low risk group”. Given that a conversion was not an option for the open group, it would be interesting to know if the score was corrected on a total of 9 points instead of 12.

Finally, even if patients were divided by approach, is not clear if a laparoscopic or robotic treatment was related to any difference in outcomes. In fact, robotic colorectal surgeons experienced a technical advantage compared to laparoscopy in the case of a “difficult pelvis”, but previous studies failed to provide this evidence (4).

Gheza F
Arru L
Baiocchi GL

Department of surgery
University of Illinois at Chicago
Chicago, IL
USA
federicoghezamd@gmail.com

References:
1. Escal L, Nougaret S, Guiu B, Bertrand MM, de Forges H, et al. MRI-based score to predict surgical difficulty in patients with rectal cancer. Br J Surg 2017 Oct 31 [Epub ahead of print]
2. Hudsmith LE, Petersen SE, Francis JM, Robson MD, Neubauer S. Normal human left and right ventricular and left atrial dimensions using steady state free precession magnetic resonance imaging. J Cardiovasc Magn Reson 2005; 7: 775-782.
3. Harr JN, Haskins IN, Amdur RL, Agarwal S, Obias V. The effect of obesity on laparoscopic and robotic-assisted colorectal surgery outcomes: an ACS-NSQIP database analysis. J Robot Surg 2017 Sep 12. [Epub ahead of print]
4. Park JS, Kim NK, Kim SH, Lee KY, Lee KY, et al. Korean Laparoscopic Colorectal Surgery Study Group. Multicentre study of robotic intersphincteric resection for low rectal cancer. Br J Surg 2015; 102: 1567-1573.