The Australasian study, which included 26 surgeons at 24 sites in Australia and New Zealand, began with 475 patients.2 It reported successful resection in 194 patients (82%) in the laparoscopic group and in 208 patients (89%) of the open surgery group (risk difference of -7.0%; 95% CI: -12.4% to ∞; P for noninferiority = 0.38).

The North American analysis also found that operative time was “significantly longer” for the laparoscopic procedure, adding a mean difference of 45.5 minutes to the operation, and extending the overall time to a mean of 266.2 minutes compared to 220.6 for the open resection.1

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The Australasian study found a median difference of 20 minutes between the techniques, with laparoscopic surgeries taking a median of 210 minutes compared to 190 minutes for the open procedure.2

Neither study found significant differences in the length of hospital stay or major complications.

Both studies advised caution in considering the less invasive procedure.

“Even though our trial was not designed to demonstrate whether one method of rectal dissection was superior to the other, the inability to establish noninferiority suggests that surgeons should be cautious when considering the suitability of a laparoscopic approach for a patient with rectal cancer,” the authors of the Australasian study wrote. 

“Subgroup analyses raise the possibility that laparoscopic surgery might be less successful than open surgery in patients who have received neoadjuvant therapy, have larger T3 tumors, or have higher BMIs.”2

The North American analysis went on to offer an explanation of why the less invasive procedure failed to meet the criteria for noninferiority, and to suggest that future developments may help overcome those limitations.1

Proctectomy is challenging to begin with, the authors wrote, and “it can be even more difficult to work in the deep pelvis with in-line rigid instruments from angles that require complicated maneuvers to reach the extremes of the pelvis.”

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However, they continued, “It is possible that modification of instruments or a different platform such as robotics will improve the efficacy of minimally invasive techniques.”

Both studies are continuing to collect follow-up data on disease-free survival and rate of local recurrence.


  1. Fleshman J, Branda M, Sargent DJ, et al., Effect of laparoscopic-assisted resection vs open resection of stage II or III rectal cancer on pathologic outcomes: the ACOSOG Z6051 randomized clinical trial, JAMA. 2015;314(13):1346-1355.
  2. Stevenson ARL, Solomon MJ, Lumley JW, et. al. Effect of laparoscopic-assisted resection vs open resection on pathological outcomes in rectal cancer: the ALaCaRT randomized clinical trial, JAMA. 2015;314(13):1356-1363.