[1] Concord Hosp, Dept Colorectal Surg, Sydney, NSW 2139, Australia
[2] Univ Sydney, Sydney Med Sch, Discipline Surg, Sydney, NSW, Australia
[3] Liverpool Hosp, Dept Colorectal Surg & Surg, Sydney, NSW, Australia
[4] Western Sydney Univ, Sch Med, Sydney, NSW, Australia
[5] Concord Hosp, Div Anat Pathol, Sydney, NSW, Australia
[6] Univ Sydney, Sydney Med Sch, Discipline Pathol, Sydney, NSW, Australia