Extended (D2) and superextended (D3) lymphadenectomy for gastric cancer. Postoperative outcome and risk factors for complications

Objective: Postoperative outcome and potential risk factors for complications after D2 and D3 lymphadenectomy have been analyzed in the present prospective observational study. Summary Background Data: Only few studies fromWestern centers compared D2 and D3 dissection in surgical treatment of gastric cancer. Methods: A total of 330 consecutive patients operated on at the same surgical department, of which 251 submitted to D2 lymphadenectomy and 79 treated by D3, were considered. Surgical treatment was performed according to the criteria described by the Japanese Research Society for Gastric Cancer. D3 lymphadenectomy, with respect to D2, involved the Kocher manoeuvre and the removal of para-aortic lymph nodes (number 16, in particular a2 and b1 subgroups), as well as the systematic removal of compartment 3 lymph nodes. Each lymph node station was removed and classified either during the operation or from the resected specimen, and single lymph nodes were retrieved in the fresh specimen and then submitted to histopathological examination. Twenty potential risk factors for morbidity and mortality have been studied by means of univariate and multivariate analysis. Results: A mean of 36 ± 15 lymph nodes (median 34, range: 12-99) after D2 and 53 ± 20 lymph nodes (median 49, range: 16-110) after D3 lymphadenectomy were removed (p<0.001). Overall morbidity and mortality rates were 34% (111 patients) and 4% (14 patients), respectively. Abdominal abscess, anastomotic leakage, pleuropulmonary diseases and pancreatitis were the most commonly observed complications. No differences in morbidity, surgical morbidity, mortality rates and mean hospital stay between D2 and D3 lymphadenectomy were found. By multivariate analysis, ASA class II/III vs. I, perioperative blood transfusions, and low albumin serum levels resulted as independent predictors of postoperative complications. Age, surgical radicality (R1/R2 vs. R0), and low albumin serum levels independently predicted mortality. Stratified analysis identified subgroups of patients with very low or very high risk of postoperative mortality. Mortality rate was 0.5% in 203 patients submitted to curative surgery and aged 75 years or younger. Most of deaths were observed in patients older than 75 years with low albumin serum levels or treated by non-curative surgery. Conclusions: D2 lymphadenectomy represents a feasible procedure related to acceptable morbidity and mortality rates. In specialized centers, D3 lymphadenectomy may be performed without increasing the risk of post-operative complications and associated deaths in carefully selected patients. These techniques should be avoided in subgroups of patients with an high risk of postoperative mortality.