title: Intra-arterial methylene blue injection into ex vivo colorectal cancer specimens improves lymph node staging accuracy: a randomized controlled trial.
abstract: OBJECTIVE
  A randomized controlled trial was carried out to study the effect of a recently proposed technique of ex vivo intra-arterial methylene blue injection of the surgical specimen removed for colorectal cancer on lymph node harvest and staging.
  
  
  METHODS
  Between May 2012 and February 2013, 100 consecutive colorectal cancer resection specimens in a single institution were randomly assigned to intervention (methylene blue injection) and control (standard manual palpation technique) groups before formalin fixation. The specimen was then examined by the histopathologist for lymph nodes.
  
  
  RESULTS
  Both groups were similar for age, sex, site of tumour, operation and tumour stage. In the intervention group, a higher number of nodes was found [median 23 (5-92) vs. 15 (5-37), P < 0.001], with only one specimen not achieving the recommended minimum standard of 12 nodes [1/50 (2%) vs. 8/50 (16%), P = 0.014]. However, there was no upstaging effect in the intervention group [23/50 (46.0%) vs. 20/50 (40.0%); P = 0.686]. With a significantly lower number of nodes harvested in rectal cancer, the positive effect of the intervention was particularly observed in the patients who underwent preoperative neoadjuvant radiotherapy [median 30 nodes (12-57) vs. 11 (7-15); P = 0.011; proportion of cases with < 12 nodes 0/5 vs. 5/8 (62.5%), P = 0.024].
  
  
  CONCLUSIONS
  Ex vivo intra-arterial methylene blue injection increases lymph node yield and can help to reduce the number of cases with a lower-than-recommended number of nodes, particularly in patients with rectal cancer having neoadjuvant treatment. The technique is easy to perform, cheap and saves time.
authors.affiliation: Department of Colorectal Surgery, North Tees and Hartlepool NHS Foundation Trust, University Hospital of North Tees, Stockton-on-Tees, UK.
authors.forename: D W
authors.initials: DW
authors.lastname: Borowski
authors.forename: B
authors.initials: B
authors.lastname: Banky
authors.forename: A K
authors.initials: AK
authors.lastname: Banerjee
authors.forename: A K
authors.initials: AK
authors.lastname: Agarwal
authors.forename: M A
authors.initials: MA
authors.lastname: Tabaqchali
authors.forename: D K
authors.initials: DK
authors.lastname: Garg
authors.forename: C
authors.initials: C
authors.lastname: Hobday
authors.forename: M
authors.initials: M
authors.lastname: Hegab
authors.forename: T S
authors.initials: TS
authors.lastname: Gill
mesh_terms: D000005:Abdomen; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000601:surgery; D004396:Coloring Agents / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007267:Injections; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008751:Methylene Blue / Q000008:administration & dosage; D008875:Middle Aged; D009367:Neoplasm Staging; D063868:Patient Outcome Assessment
chemical_list: D004396:Coloring Agents; D008751:Methylene Blue
keywords: Colorectal cancer; lymph node harvest; methylene blue; randomized controlled trial; staging