Stanton Anthony W B, Modi Stephanie, Mellor Russell H, Levick J Rodney, Mortimer Peter S
Division of Cardiac & Vascular Sciences, Dermatology, St George's Hospital Medical School, University of London, London, United Kingdom.
Lymphat Res Biol. 2009;7(1):29-45. doi: 10.1089/lrb.2008.1026.
Axillary surgery for breast cancer may be followed, months to years later, by chronic arm lymphedema. A simple 'stopcock' mechanism (reduced lymph drainage from the entire limb through surviving lymphatics) does not explain many clinical aspects, including the delayed onset and selective sparing of some regions, e.g., hand. Quantitative lymphoscintigraphy reveals that lymph drainage is slowed in the subcutis, where most of the edema lies, and in the subfascial muscle compartment, which normally has much higher lymph flows than the subcutis. Although the muscle does not swell significantly, the impaired muscle drainage correlates with the severity of arm swelling, indicating a likely key role for muscle lymphatic function. A new method, lymphatic congestion lymphoscintigraphy, showed that the edema is associated with a reduced contractility of the arm lymphatics; the weaker the active lymphatic pump, the greater the swelling. Delayed lymphatic pump failure may result from chronic raised afterload, as in hypertensive cardiac failure, and may account for the delayed onset of swelling. A further novel finding is that lymph flow is raised in both the subcutis and muscle of both arms in postsurgical breast patients who later developed breast cancer-related lymphedema (BCRL), compared with patients who did not develop BCRL. This new observation indicates a predisposition to BCRL in some women. Further evidence for predisposing abnormalities is the finding of lymphatic abnormalities in the contralateral (nonswollen) arm in women with established BCRL. Such predisposing factors could explain why some women develop BCRL after sentinel node biopsy, whereas others do not after clearance surgery. Future research must focus on prospective observations made from before surgery until BCRL develops.
乳腺癌腋窝手术后,数月至数年后可能会出现慢性手臂淋巴水肿。一种简单的“旋塞”机制(通过存活的淋巴管减少整个肢体的淋巴引流)并不能解释许多临床现象,包括延迟发作和某些区域(如手部)的选择性幸免。定量淋巴闪烁造影显示,在大部分水肿所在的皮下组织以及正常情况下淋巴流量比皮下组织高得多的筋膜下肌肉间隙中,淋巴引流减慢。虽然肌肉没有明显肿胀,但肌肉引流受损与手臂肿胀的严重程度相关,表明肌肉淋巴功能可能起关键作用。一种新方法,即淋巴充血淋巴闪烁造影显示,水肿与手臂淋巴管收缩力降低有关;活跃的淋巴泵越弱,肿胀越严重。淋巴泵功能延迟衰竭可能是由于慢性后负荷增加所致,就像高血压性心力衰竭一样,这可能解释了肿胀的延迟发作。另一个新发现是,与未发生乳腺癌相关淋巴水肿(BCRL)的患者相比,后来发生BCRL的乳腺癌术后患者双臂的皮下组织和肌肉中的淋巴流量均增加。这一新观察结果表明,一些女性存在发生BCRL的易感性。存在易患异常的进一步证据是,已确诊BCRL的女性对侧(未肿胀)手臂存在淋巴异常。这些易感因素可以解释为什么一些女性在进行前哨淋巴结活检后会发生BCRL,而另一些女性在进行清扫手术后却不会。未来的研究必须集中在从手术前到BCRL发生的前瞻性观察上。