Distribution of Perigastric Station 4d Lymph Nodes in Vascularized Gastroepiploic Lymph Node Transfer: An Anatomic Study and Case Series

Background: Vascularized gastroepiploic lymph node transfer (VGLNT) is a well-accepted surgical treatment for restoring physiological function in chronic lymphedema. However, the inclusion of substantial lymph nodes (LNs) in the flap remains uncertain. This study aimed to identify the anatomical basis for reliable flap harvest for VGLNT. Patients and Methods: The anatomy of perigastric station 4d LNs was studied in healthy cadavers (n = 15) and patients with early gastric cancer (EGC) (n = 27). The omentum was divided into three segments: proximal, middle, and distal from the origin of the right gastroepiploic vessels. The flap dimension, number, location, size of LNs, and caliber of the vessels were reviewed. Eight patients underwent VGLNT for upper/lower limb lymphedema. Results: The mean numbers of LNs in the proximal, middle, and distal segment were 2.5, 1.4, 0.5 in the cadavers, and 4.9, 2.7, 0.7 in the gastrectomy specimens, respectively. The proximal third included a significantly greater number of LNs than the distal third in the cadaveric (p = 0.024) and ECG (p = 0.016) specimens. A total of 95% of the LNs were located within proximal two-thirds of the flap from the vessel origin both in the cadavers (21.0 × 5.0 cm) and in the gastrectomy specimens (20 × 3.5 cm). In VGLNT, the transferred flap was 25.5 ± 6.9 × 4.1 + 0.7 cm in dimension, containing a mean number of 6.5 ± 1.9 LNs. At postoperative 6 months, the volumetric difference was significantly reduced by 22.8 ± 9.2% (p < 0.001). Conclusions: This study provides a distinct distribution pattern of station 4d LNs. Inclusion of the proximal two-thirds of the flap, which carries majority of the LNs, is recommended for VGLNT.