第2掌背动脉游离皮瓣的解剖及临床应用

Free flap of second dorsal metacarpal artery: anatomical study and clinical application

目的:观察第2掌背动脉(SDMA)手背至指蹼的走行及皮支分布情况,探讨SDMA皮瓣游离移植的可行性及临床效果。方法:2018年6月至2018年9月,唐山市第二医院手外科对22只手标本进行红色乳胶灌注后,解剖观察SDMA的走行、血管外径及皮支分布情况,以及是否有固定的皮神经支配。2019年2月至2020年7月,切取游离SDMA皮瓣修复拇指指腹缺损2例,左、右侧各1例,均为男性。均为挤压伤,拇指指腹缺损面积分别为3.5 cm×2.0 cm和2.0 cm×2.5 cm。均无神经、血管损伤,其中1例合并末节指骨骨折,伴有甲床裂伤。皮瓣切取面积分别为3.8 cm×2.3 cm和2.8 cm×2.5 cm。术后3周开始功能锻炼。术后采用门诊复诊、电话或网络方式定期随访,观察皮瓣外观、质地、感觉恢复情况及手指功能等。结果:SDMA走行过程中,沿途发出4~9条穿支,集中在远侧1/3。SDMA与示指伸肌腱交叉处外径为(0.76±0.25)mm;指蹼动脉外径为(0.71±0.12)mm;指蹼动脉长为(11.00±1.27)mm。在浅筋膜深层有1条桡神经浅支,横径(1.20±0.09)mm,自鼻烟窝斜向尺侧远端,支配第2、3掌骨之间远侧及示、中指指蹼皮肤感觉。2例皮瓣均成活,皮瓣血运正常,伤口Ⅰ期愈合。1例随访18个月,受区皮瓣血运良好,质地柔软,弹性好,指腹饱满,外形美观,无破损,无色素沉着。两点辨别觉(TPD)为7.0 mm。另外1例随访15个月,手指活动良好,皮瓣皮肤柔软,弹性好,TPD为7.5 mm。根据中华医学会手外科学会上肢部分功能评定标准进行评定,结果均为优。结论:SDMA皮瓣的动脉血管直径适宜吻合,有较粗的浅静脉,有固定的皮神经支配,适合游离移植,可用于修复拇指指腹及指端的软组织缺损。

Objective To observe the path and anatomic distribution of cutaneous branch of second dorsal metacarpal artery(SDMA)from the back of hand to the web of the fingers,and to explore the feasibility and clinical effect on the transfer of free flap of SDMA.Methods Between June 2018 and September 2018,with perfusion of red latex,22 hand specimens were dissected to explore the course,vessel calibre and distribution of cutaneous branches of SDMA,and to discover the existence of an innervation of cutaneous nerve in Department of Hand Surgery of Tangshan Second Hospital.Later on,from February 2019 to July 2020,2 thumb pulp defects of 2 patients were reconstructed with the free flaps of SDMA.One defect was in the left thumb and the other in the right,both were male and compression injuries.Size of thumb pulp and a skin defect was at 3.5 cm×2.0 cm in 1 patient,and 2.0 cm×2.5 cm in the other.There was no neurovascular injury,but 1 patient had a distal phalangeal fracture and a nail bed laceration.The sizes of the flaps were 3.8 cm×2.3 cm and 2.8 cm×2.5 cm.Functional exercises started from 3 weeks after surgery.Patients attended postoperation follow up regularly by outpatient visit,telephone or internet interviews.Follow-up observations included the appearance,texture,sensory recovery of the flaps and thumb functions.Results Multiple perforating branches(4-9 branches)were found from SDMA,which distributed in the distal 1/3 of SDMA in the anatomic study.It was found that the outer diameter of SDMA was 0.76 mm±0.25 mm at the intersection of extensor tendon of index finger and that of the digital web artery was 0.71 mm±0.12 mm.The length of digital web artery was 11.00 mm±1.27 mm.The 2 surgically transferred flaps were all survived.One patient showed the function of thumb in excellent with two-point discrimination(TPD)at 7.0 mm,at 18 months of follow-up.The other patient showed good thumb movement,soft and elastic skin of the flap and with a 7.5 mm in TPD,at 15 months of follow-up.According to the Evaluation Standard of Upper Limb Partial Functional of Hand Surgery of Chinese Medical Association,the results of the 2 flaps were all excellent.Conclusion The flap of SDMA has a constant cutaneous nerve and a long vascular pedicle with an ideal vessel size.It is suitable for free transfer and can be used to reconstruct soft tissue defects of thumb.