tailieunhanh - Upper Gastrointestinal Surgery - part 9

Mô hình của bạch huyết lây lan của ung thư thực quản Một kiến thức thân mật của hệ thống dẫn lưu bạch huyết là điều kiện tiên quyết cho bất kỳ phương pháp bóc tách hạch bạch huyết. | 32 . z SURGICAL RESECTION FOR ESOPHAGEAL CANCER ROLE OF EXTENDED LYMPHADENECTOMY specific risk scoring system and exclusion of high risk patients from surgery Figure . Such results can however only be achieved in experienced centers with a high patient load high volume centers . Lymphadenectomy for Esophageal Cancer Although the principle of lymphadenectomy for tumors of the gastrointestinal tract was introduced more than 100 years ago the value of lymph node dissection in patients with esophageal cancer still remains controversial. While extensive lymphadenectomy is advocated by some in order to reduce the rate of local recurrences and prolong survival others argue that the claimed benefits of extensive lymph node dissection in patients with esophageal cancer have not been proven and that lymphadenectomy may in fact increase the morbidity and mortality of esophageal resection 7 . Pattern of Lymphatic Spread of Esophageal Cancer An intimate knowledge of the lymphatic drainage system is the prerequisite for any approach to lymph node dissection. Key to the understanding of the lymphatic drainage of an organ is the comprehension of its embryogenesis. The esophagus originates from two different tissue sources . the branchial arches and pharyngeal pouches orally and the splanchnic mesoderm aborally. Both join during the embryonic and fetal development but keep a delimitation at the level of the tracheal bifurcation even during adult life. This results not only in a bilateral oral and aboral vascular supply but also in a corresponding bilateral lymphatic drainage Figure . In patients with early stage esophageal cancer the pattern of lymph node spread follows these anatomical pathways. The location of the primary tumor thus determines the direction of lymphatic drainage and consequently the location of lymph node metastases. Tumors located above the level of the tracheal bifurcation Figure . Decreasing postoperative mortality after esophagectomy for .