Lymphatic drainage from esophagogastric tract: feasibility of endoscopic CT lymphography for direct visualization of pathways.
OBJECTIVE
To evaluate the feasibility of an endoscopic computed tomographic (CT) lymphography technique with submucosal injection of iopamidol for direct visualization of lymphatic drainage pathways in dogs and in patients with operable esophageal cancer.


METHODS
With institutional animal committee approval, a total of 2 mL of undiluted iopamidol was injected into the esophageal (n = 6) or gastric (n = 3) submucosa in nine dogs by using a flexible endoscope. Multi-detector row CT images (section thickness, 1.25 mm) were obtained before contrast material injection and during the 10 minutes after injection. The animals were euthanized so that their lymphatic anatomy could be examined. With ethical committee approval and patient informed consent, nine patients with esophageal cancer also underwent CT lymphography with peritumoral injection of 2 mL of iopamidol, followed by esophagectomy and regional lymph node dissection with CT lymphographic guidance. The histopathologic features of dissected nodes, including sentinel lymph nodes (SLNs), were examined.


RESULTS
CT lymphography depicted the direct connection of lymphatic drainage vessels with enhanced and/or unenhanced nodes (ie, SLNs) as early as within 5 minutes after contrast material injection in all subjects. All 13 SLNs in dogs (1.4 nodes per animal) and 18 SLNs in patients (two nodes per patient) were found and dissected at the correct location by using CT lymphographic guidance. In patients, histopathologic examination revealed the high predictive value of CT lymphographic-guided SLN biopsy: Only one of the preoperatively identified SLNs in three patients and both SLNs and adjacent nodes in two patients were positive for metastasis; all resected nodes in the remaining four patients were negative.


CONCLUSIONS
Endoscopic CT lymphography is a feasible method for visualizing the direct connection between and the accurate anatomic location of SLNs and lymphatic drainage vessels.
Suga
Kazuyoshi
K
Department of Radiology, Yamaguchi University School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan. sugar@po.cc.yamaguchi-u.ac.jp
Shimizu
Kensaku
K
Kawakami
Yasuhiko
Y
Tangoku
Akira
A
Zaki
Mohammed
M
Matsunaga
Naofumi
N
Oka
Masaaki
M
D000368:Aged; D000818:Animals; D003287:Contrast Media; D004285:Dogs; D016099:Endoscopy, Gastrointestinal; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging*; D005240:Feasibility Studies; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging*; D008220:Lymphography / Q000379:methods*; D008875:Middle Aged; D014057:Tomography, X-Ray Computed
D003287:Contrast Media