SEATTLEIntraoperative colon-oscopy with lesion tattooing and lymphatic
mapping during laparoscopic colectomy can improve accuracy in identifying a
small primary colorectal neoplastic lesion and its lymphatic drainage,
according to a study presented at the President’s Plenary Session of the 67th
Annual Scientific Meeting of the American College of Gastroenterology (ACG
The technique assisted in guiding resection and improved staging of
patients with colorectal cancer, said lead author Nicholas Karyotakis, MD, an
attending physician at Cedars-Sinai Medical Center, and chief scientific
officer of Gastrointestinal Biosciences, Los Angeles.
"The 5-year survival for colorectal cancer has not improved all that much
over the last 15 years," Dr. Karyotakis said. "The problem is that 30% of
colorectal cancers at stage II tend to recur. Is that because of
false-negative nodal status? We believe that direct examination of the lymph
nodes of the surgical specimen may improve detection."
The main obstacle to lymph node examination is that every surgical
specimen usually has 15 to 20 or more nodes that need to be meticulously
dissected and examined. Dr. Karyotakis and his colleagues hope to improve
upon this procedure by using lymphatic mapping to identify the sentinel nodes
for closer examination.
The sentinel node is the first regional node in the lymphatic drainage
pathway from the primary neoplasm, and the tumor status of the sentinel node
reflects the tumor status of the nodal basin. "Sentinel lymph node mapping
has been used for many years in melanoma and breast cancer, and we’re trying
to use this technology in the gastrointestinal tract," Dr. Karyotakis said.
The researchers looked at 22 patients (median age, 65 years) who had
small, early-stage colorectal neoplasms. The distribution of lesions by
location was as follows: rectum, 2 patients (9%); left colon, 6 patients
(28%); and right colon, 14 patients (63%). The median size of the lesions was
2.2 cm (range, 0.3 to 5 cm). The primary lesion was a dysplastic polyp in 4
patients (18%), stage T1 in 11 patients (50%), stage T2 in 4 patients (18%),
and stage T3 in 3 patients (14%).
The study subjects all underwent intraoperative colonoscopy, with tumor
site identification done laparoscopically, and efferent lymph channels
tracked to the sentinel nodes using blue dye. The sentinel nodes were marked
and sent to pathology along with the surgical specimen. Colonoscopy and
lymphatic mapping added only about 15 minutes to the total operative time.