AB08. Elective splenic artery and splenic hilar nodal dissection in radical gastrectomy for proximal gastric cancer

Objective: To investigate the clinical significance of No.4 lymph nodes(LNs) in predicting No.10 and No.11 LNs metastasis and the appliance of intraoperative rapid immunohistochemical staining (RIHC, enhanced polymer one-step staining). A prospectively randomized clinical trial was undertaken to assess the effect of D2 compared with elective D2 lymphadenectomy for proximal gastric cancer.

Methods: Between June 2012, and December 2012, a total of 193 patients with advanced proximal gastric cancer were entered and randomly assigned to D2 lymphadenectomy (DL 95 patients) or to elective D2 lymphadenectomy (EDL 98 patients) at Chinese PLA general hospital. All the patients in Group DL received standard D2 lymphadenectomy (pancreas-preserving and spleen-preserving). No.4 LNs were dissected during surgery to detect metastasis by RIHC frozen section in Group EDL. Patients with positive No.4 LNs received standard D2 lymphadenectomy. Patients with negative No.4 LNs received D2 lymphadenectomy without splenic artery and splenic hilar nodal dissection. The clinical findings of patients involved in the trial were analyzed.

Results: A logistic regression analysis showed that the age, N Stage, No.4sa, No.4sb LNs were significant parameters for No. 10, 11 LNs metastasis (P<0.05). Compared with postoperative HE staining, the sensitivity, specificity, diagnostic accuracy of the intraoperative enhanced polymer one-step staining (EPOS) were 94.12%, 98.44%, 96.44%. It took 35.2±19.4 minutes (21~48) for the whole test. There was significant difference in time of surgery, the amount of intraoperative bleeding, recovery and length of hospital (193.8±43.2 vs. 276.4±52.9 minutes; 217.4±98.2 vs. 283.6±117.2 mL; 5.6±1.5 vs. 6.8±2.2 days; 11.6±2.5 vs. 14.7±4.7 days; P<0.001) between the patients with negative No.4 LNs in Group EDL (n=66) and the patients with negative No.4 LNs in Group EDL (n=65), but no difference in postoperative morbidity, mortality, recovery, tumor recurrence and survival curves were found. The median follow-up for 193 patients was 7 months (range, 3-12 months), none of which have tumor recurrence or died.

Conclusions: The risk of metastasis to No.10, 11 LNs were high with the condition that older age, late N stage, the positive No.4sa, No.4sb LNs. No.4 LNs could be a good indicator of No.10 and No.11 LNs metastasis. Patients with No.4 LNs tested in the operation by RIHC could get benefits from elective D2 lymphadenectomy in short-term prognosis. Long-term prognosis needs further follow-up and investigation.

Keywords: Splenic hilar nodes; splenic artery nodes; lymphadenectomy; intraoperative rapid immunohistochemical staining