Radiological and pathological evaluation of the level of arterial division after colon cancer surgery

In aiming to cure patients with colorectal cancer surgery, the surgeon must carefully dissect the mesocolon and mesorectum and divide the vascular pedicle near to its origin so as to include all local lymph nodes. This has been termed complete mesocolic excision. The distance from the distal vascular tie to the bowel wall in the fixed specimen is an indication as to the quality of surgery but this does not assess the length of the residual vascular pedicle and, by implication, residual lymph nodes. The aim of this study was to establish if our surgeons were carrying out complete mesocolic excision by assessing the length of the proximal arterial pedicle and relating this to arterial length in the fixed specimen.

This was a single centre prospective study of patients undergoing elective surgery for locally advanced colorectal cancer. An abdominal and pelvic CT scan was performed 2 days postoperatively and a radiologist blinded to the operative procedure measured the length of the residual arterial stump. Similarly, the length of the vessel in the fixed resected specimen and lymph node yield were also recorded.

Fifty-two patients were recruited. The mean length of the residual arterial stump was 38 mm (95% CI: 33-43), which was significantly longer than the < 10 mm recommended in guidelines (P < 0.0001). The mean length was 31 mm (95% CI: 25-37) and 49 mm (95% CI: 40-57) for left and right sided resections respectively. There was no correlation between the residual arterial stump and the pathology.

The residual arterial length was greater than suggested by guidelines and may indicate that our surgery is less radical than we planned. Caution should be taken when using pathological measurements of vascular ligation as it may not reflect the height of the pedicle division.