Hepatic lymphatic mapping: a pilot study for porta hepatis lymph node identification

Liver lymphatic drainage patterns follow segmental anatomy in a murine model

The liver’s cellular functions are sustained by a hierarchical, segmentally-organized vascular system. Additionally, liver lymphatic vessels are thought to drain to perihepatic lymph nodes. Surprisingly, while recent findings highlight the importance of organ-specific lymphatics, the functional anatomy of liver lymphatics has not been mapped out. In literature, no segmental or preferential lymphatic drainage patterns are known to exist. We employ a novel murine model of liver lymphangiography and in vivo microscopy to delineate the lymphatic drainage patterns of individual liver lobes. Our data from blue dye liver lymphangiography show preferential lymphatic drainage patterns: Right lobe mainly to hepatoduodenal ligament lymph node 1 (LN1); left lobe to hepatoduodenal ligament LN1 + LN2 concurrently; median lobe showed a more variable LN1/LN2 drainage pattern with increased (sometimes exclusive) mediastinal thoracic lymph node involvement, indicating that part of the liver can drain directly to the mediastinum. Upon ferritin lymphangiography, we observed no functional communication between the lobar lymphatics. Altogether, these results show the existence of preferential lymphatic drainage patterns in the murine liver. Moreover, this drainage can occur directly to mediastinal lymph nodes and there is no interlobar lymphatic flow. Collectively, these data provide the first direct evidence that liver lymphatic drainage patterns follow segmental anatomy.

Absence of Maternal Microchimerism in Regional Lymph Nodes of Children With Biliary Atresia

OBJECTIVE

Maternal lymphocytes have been cited as a potential cause of infantile biliary atresia (BA). When hepatoportoenterostomy is performed, locoregional lymphadenopathy is frequently encountered.

METHODS

We screened enlarged nodes from 6 consecutive nonsyndromatic BA patients (age: 68 days ± 18.9 days) for maternal elements using DNA fingerprinting with short tandem repeat analysis and quantitative real-time polymerase chain reaction for allelic (single nucleotide) sequence polymorphisms.

RESULTS

Although being partly positive in infants' peripheral blood, no maternal microchimerism could be demonstrated in any of the lymph nodes.

CONCLUSION

This result challenges the hypothesis that maternal cells play a role in hilar lymphadenopathy of children with BA.

Intraoperative Hepatic Lymphatic Mapping in Patients with Liver Metastases from Colorectal Carcinoma

The survival of patients undergoing liver resection for colorectal metastases is poor in the presence of extrahepatic disease. Therefore identification of periportal and celiac lymph node metastases is central to proper patient selection. In this study we examined the technique of intraoperative hepatic lymphatic mapping with isosulfan blue dye in humans. Intrahepatic dye injection was performed in patients undergoing surgical exploration for colorectal liver metastases. The location of all blue-stained lymphatics and lymph nodes was recorded. All stained and unstained lymph nodes were biopsied for pathologic examination. Thirteen intraoperative lymphatic mapping procedures were performed in 11 patients. A blue-stained lymphatic was visualized in 11 of 13 injections (85%). A blue lymph node was visualized in seven of 13 injections (54%). Three of the seven blue nodes (43%) were not detected by the surgeon before the mapping procedure. There were no complications associated with the intrahepatic dye injections. All biopsied lymph nodes were negative for metastatic tumor. We conclude that intraoperative hepatic lymphatic mapping with isosulfan blue dye is a simple, rapid, and safe technique in humans. It may serve as an adjunct to random lymph node biopsy for the identification of periportal and celiac nodal metastases before liver resection in patients with metastatic colorectal carcinoma.