Over 5 million new rectal cancer diagnoses are made globally per year. The mainstay of treatment is to offer a total mesorectal excision (TME) with or without concurrent neo-adjuvant chemo-radio-therapy, thereby offering a 63–64% overall survival at 5 years with complete (R0) resection [1]. This is true for rectal cancers in the absence of a threatened resection margin. However, 5–10% transgress the conventional resection margin (CRM) and invade adjacent structures at the time of diagnosis. In addition, despite high quality TME surgery in cases where tumour does not threaten the CRM, there is a 10% local recurrence rate.