Predictive factors for lymph node metastasis and endoscopic treatment strategies for undifferentiated early gastric cancer.

BACKGROUND AND AIM: Although more than 80% of undifferentiated early gastric cancers (EGC) are not associated with lymph node metastasis, endoscopic mucosal resection is not generally accepted as a means of curative treatment because of an abundance of conflicting data concerning clinicopathological characteristics and prognoses. The aim of this study was to define a subgroup of undifferentiated EGC that could be cured by endoscopic treatment without the risk of lymph node metastasis. METHOD: A total of 591 patients surgically resected for undifferentiated EGC between January 1999 and March 2005 were reviewed. Associations between various clinicopathological factors and the presence of lymph node metastasis were analyzed to identify the risk factors of lymph node metastasis. RESULTS: Lymph node metastasis was found in 79 patients (13.4%). By multivariate logistic regression analysis, a tumor diameter 2.5 cm or larger, invasion into the middle third of the submucosal layer or deeper, and lymphatic involvement were identified as independent risk factors of lymph node metastasis (P < 0.001, respectively). Lymph node metastasis was not found in any patient with undifferentiated EGC smaller than 2.5 cm confined to the mucosa or upper third of the submucosal layer without lymphatic involvement. CONCLUSIONS: Undifferentiated intramucosal EGC smaller than 2.5 cm without lymphatic involvement was not associated with lymph node metastasis. Thus, we propose in this circumstance that endoscopic mucosal resection could be considered a definitive treatment without compromising the possibility of cure.

Safety of modified extended right hepatectomy in living liver donors.

In living donor liver transplantation (LDLT), the standard right graft has been adopted by many centers to meet the metabolic demands of large recipients. In conventional right liver graft, congestion at anterior section may be problematic especially when graft volume is insufficient. We previously introduced a technical aspect of modified extended right hepatectomy (MERH), in which the middle hepatic vein was excavated by preserving the entire segment 4 (Sg4) to the donor. In this report, we investigated the safety of donors who received MERH. Between August 2002 and July 2005, 97 donors underwent right liver donation. MERH was considered when remnant-left liver volume exceeded 35% of whole liver. Eighteen donors underwent MERH (MERH group, n=18). We compared the clinical outcomes of MERH group with those of donors who underwent conventional right hepatectomy (RH) with remnant liver volume exceeding 35% (RH group, n=37). No donor mortality occurred. No intra-operative transfusion and no re-operation were performed. There were no differences in operative time (290.8 min in MERH group vs. 297.0 min in RH group, respectively), blood loss (453.3 ml vs. 426.5 ml), and postoperative hospital stay (12.5 days vs. 12.8 days) between the two groups (P>0.05). Period of drain removal was longer in MERH group (12.5 days vs. 9.4 days, P<0.05). But, there was no difference in complication rate between the two groups (11/18 vs. 23/37, P>0.05). Computed tomography scan showed that congestion of Sg4 was occurred in 13 out of 18 MERH donors in early postoperative period, but all recovered at 4 months. The regeneration of the remnant liver after MERH and RH were similar (209.8% vs. 200.0% at 4 months, P>0.05). Our results show that MERH did not impair recovery or liver regeneration in donors, and indicate that MERH can be safely done in adult LDLT when the remnant liver exceeds 35%.