背阔肌解剖变异在乳腺癌腋窝淋巴结清扫术中的临床意义

Clinical Significance of Latissimus Dorsi Mutation in Axillary Lymph Node Dissection for Breast Carcinoma

目的:通过对腋窝处变异的背阔肌进行详尽解剖,为降低乳腺癌腋窝淋巴结清扫术中腋窝处重要神经血管损伤,减少手术并发症提供依据。方法:收集128例行腋窝淋巴结清扫术的乳腺癌患者中发生背阔肌解剖变异19例,对该19例患者的背阔肌变异肌束进行详尽的大体解剖,找到其起点与止点,并测量长、宽、厚度,观察与腋窝神经、血管、淋巴结的毗邻关系。结果:19例发生背阔肌解剖变异的肌束均从背阔肌外侧缘发出一束肌腱,向内上走行,横跨腋血管神经束,在其上方,呈"扇形"腱膜延续为喙锁胸筋膜的一部分止于喙突。其中14例为单肌束走行,5例变异肌束从背阔肌发出后与胸大肌外缘发出一肌束会合,再并行向上。该变异肌束与背阔肌止端健呈"丫"型夹持着腋血管神经束。肋间臂神经从其表面或深面通过。其内下侧毗邻胸背神经及肩胛下血管,后外毗邻肩胛下血管外淋巴组织。结论:背阔肌变异肌束可造成腋窝淋巴结清扫术的解剖混淆,给腋淋巴结清扫术时的定位带来困难。因此,了解此种变异在腋窝淋巴结清扫术中具有重要意义。

Objective： This study aimed to provide the basic surgical guidelines for important injured nerves and vessels in the axilla during axillary lymph node dissection and reduce surgery-related complications by dissecting the variant latissimus dorsi （LATS） in the axilla. Methods： Data of 19 cases with LATS mutation from 128 breast carcinoma cases who underwent axillary lymph node dissection were collected and studied. The start and end points of the variation of muscle bundle （VOMB） were found by analyzing a full gross anatomy of the variant muscle bundle of LATS in the 19 cases. Length, width, and depth of VOMB were measured. Adjacent relationship among the axillary nerve, blood vessels, and lymph nodes in the axilla was observed. Results： Among the 19 cases with LATS mutation, each VOMB released a bundle of tendons from the lateral border of LATS, thereby stretching inward and upward as well as across the axillary neuro- vascular bundle. Above the bundle, a fan-shaped aponeurosis extended as a part of the fascia coracocleidopectoralis, which ended at the coracoid process. Among the 19 cases, 14 VOMBs were extended by a mode of a single muscle bundle. For the remaining five cases, VOMBs converged with a bundle from the outer margin of the pectoralis major muscle after VOMB was sent out from LATS. These VOMBs then extended upward. The VOMB and the insertion of LATS muscle retained the axillary neurovascular bundle in a forked form. The intercostobrachial nerves passed through the surface or the inner part of the vessels, which adjoined the thoraco-dorsal nerve and the sub-scapular blood vessels inward and inferolaterally. The lymphatic tissues were directed outside the sub-scapular blood vessels posteroexternally. Conclusion： LATS mutation may cause confusion in the anatomical structure of the dissected axillary lymph node and likely results in difficulties in the localization during surgery. Thus, determining the VOMB in the dissected axillary lymph node is important.