Method of pedicle division during laparoscopic right hemicolectomy affects lymph node yield and short-term outcomes.

BACKGROUND: Several ways of performing laparoscopic right hemicolectomy (RHC) have evolved. The vascular pedicle can be divided into extracorporeal (RHC-EC) or intracorporeal (RHC-IC). It is not known whether vessel ligation during RHC-EC is as central as during RHC-IC. We compare these approaches in terms of pathological and short-term clinical outcomes. METHODS: Patients undergoing elective laparoscopic RHC in a single centre (July 2013-September 2016) were identified. Data collection included operative details, length of stay, complications, specimen parameters including number and involvement of lymph nodes and recurrence. RESULTS: One hundred and sixty-nine patients were included (94 RHC-IC, 75 RHC-EC). For caecal and ascending colon cancers, mesocolic width was greater after RHC-IC than RHC-EC (7.9 cm versus 6.6 cm, P < 0.05), as was lymph node yield (19.5 versus 17.3, P < 0.05). There was no significant difference in length of colon resected, distal resection margin, number of positive nodes, proportion of node-positive tumours and R1 rate. Operative duration was higher for RHC-IC (163 min versus 91 min, P < 0.001), as was incidence of ileus (35% versus 15%, P < 0.05). Length of stay also tended to be higher (7.4 days versus 6.0 days, P = 0.19). There was no difference in disease recurrence (follow-up 12 months). Body mass index was positively correlated with lymph node yield for RHC-EC, but not for RHC-IC. CONCLUSION: Lymph node yield after laparoscopic RHC is adequate, whether the vascular pedicle is taken intracorporeal or extracorporeal, supporting the use of both approaches. RHC-IC yields more lymph nodes and greater mesocolic width, but involves a longer operation and higher incidence of ileus.

Clearance of circulating tumor cells after excision of primary colorectal cancer.

OBJECTIVE: To establish whether the prevalence of positive reverse transcriptase-polymerase chain reaction (RT-PCR) results decreased during the first 3 months after colorectal cancer excision, and to assess whether persistence of RT-PCR positivity after primary colorectal cancer excision was related to tumor stage or locally advanced and metastatic disease. METHODS: Systemic venous blood was collected from patients with colorectal cancer before and at intervals up to 12 weeks after surgery. RNA was extracted from the mononuclear cell fraction of the blood samples and subjected to RT-PCR using specific primers for carcinoembryonic antigen mRNA and cytokeratin-20 mRNA. Healthy individuals with no history of cancer were used as controls. RESULTS: The results of RT-PCR were positive in 81 of 116 patients with colorectal cancer before surgery, with no significant differences in preoperative prevalence by Dukes stage or presence of locally advanced or metastatic disease. There was a significant decrease in the prevalence of RT-PCR positivity at 24 hours after surgery compared with before surgery. On subgroup analysis by Dukes stage, only the decrease in Dukes A and B patients reached significance. Seven of the 143 controls were RT-PCR positive. CONCLUSIONS: Circulating tumor cells were present before treatment in most patients with colorectal cancer regardless of tumor stage or metastases. Clearance of circulating tumor cells within 24 hours of colorectal cancer excision was greatest in tumors with the best prognosis.