The Radial Artery Superficial Palmar Branch Flap: A Modified Free Thenar Flap with Constant Innervation

ABSTRACT

The free thenar flap is useful for coverage of volar finger defects but has an inconstant innervation based on the presence of either the lateral antebrachial cutaneous nerve (LABC) or the superficial sensory branch of the radial nerve (SSRN). A detailed anatomic study on 30 adult fresh frozen cadavers preinjected with silicone rubber compound to demarcate arterial anatomy documented locations, numbers, and diameters of arteries and skin perforators with surrounding nerves. The palmar cutaneous branch of the median nerve (PCMN) was present within the flap in all cases. However, the LABC and the SSRN were available in only 43.33% and 46.66%, respectively, with neither of them in 33.33% of the cases. The constantly present PCMN allowed the design of a new flap named the radial artery superficial palmar branch (RASP) flap. The RASP flap is large enough to cover volar finger defects and contain direct skin perforators. Because it is constantly innervated, it is an excellent option for coverage of volar finger defects extending to the fingertips.

KEYWORDS

Free thenar flap - palmar cutaneous branch of the median nerve - superficial palmar branch of radial artery - volar finger defect - sensate flap

REFERENCES

• 1 Lee D C, Kim J S, Ki S H, Roh S Y, Yang J W, Chung K C. Partial second toe pulp free flap for fingertip reconstruction.  Plast Reconstr Surg. 2008;  121 899-907
• 2 Kamei K, Ide Y, Kimura T. A new free thenar flap.  Plast Reconstr Surg. 1993;  92 1380-1384
• 3 Noh S M, Kim J S, Lee D C, Roh S Y, Yang J W. Reconstruction of soft tissue defect of the finger with thenar free flap.  J Korean Soc Plast Reconstr Surg. 2008;  35 450-454
• 4 Sassu P, Lin C H, Lin Y T, Lin C H. Fourteen cases of free thenar flap: a rare indication in digital reconstruction.  Ann Plast Surg. 2008;  60 260-266
• 5 Garg R, Fung B KK, Chow S P, Ip W Y. A free thenar flap—a case report.  J Orthop Surg Res. 2007;  2 4
• 6 Omokawa S, Mizumoto S, Iwai M, Tamai S, Fukui A. Innervated radial thenar flap for sensory reconstruction of fingers.  J Hand Surg [Am]. 1996;  21 373-380
• 7 Omokawa S, Ryu J, Tang J B, Han J S. Vascular and neural anatomy of the thenar area of the hand: its surgical applications.  Plast Reconstr Surg. 1997;  99 116-121
• 8 Sakai S. Free flap from the flexor aspect of the wrist for resurfacing defects of the hand and fingers.  Plast Reconstr Surg. 2003;  111 1412-1420 discussion 1421-1422
• 9 Carroll R E, Green D P. The significance of the palmar cutaneous nerve at the wrist.  Clin Orthop Relat Res. 1972;  83 24-28
• 10 Taleisnik J. The palmar cutaneous branch of the median nerve and the approach to the carpal tunnel. An anatomical study.  J Bone Joint Surg Am. 1973;  55 1212-1217
• 11 Naff N, Dellon A L, Mackinnon S E. The anatomical course of the palmar cutaneous branch of the median nerve, including a description of its own unique tunnel.  J Hand Surg [Br]. 1993;  18 316-317
• 12 Mackinnon S E, Dellon A L. The overlap pattern of the lateral antebrachial cutaneous nerve and the superficial branch of the radial nerve.  J Hand Surg [Am]. 1985;  10 522-526
• 13 Lee T P, Liao C Y, Wu I C, Yu C C, Chen S G. Free flap from the superficial palmar branch of the radial artery (SPBRA flap) for finger reconstruction.  J Trauma. 2009;  66 1173-1179
• 14 Taylor G I, Gianoutsos M P, Morris S F. The neurovascular territories of the skin and muscles: anatomic study and clinical implications.  Plast Reconstr Surg. 1994;  94 1-36
• 15 Lundborg G. The intrinsic vascularization of human peripheral nerves: structural and functional aspects.  J Hand Surg [Am]. 1979;  4 34-41
• 16 Koshima I, Saisho H, Kawada S, Hamanaka T, Umeda N, Moriguchi T. Flow-through thin latissimus dorsi perforator flap for repair of soft-tissue defects in the legs.  Plast Reconstr Surg. 1999;  103 1483-1490
• 17 Kim J T, Kim C Y, Kim Y H. T-anastomosis in microsurgical free flap reconstruction: an overview of clinical applications.  J Plast Reconstr Aesthet Surg. 2008;  61 1157-1163
• 18 Koshima I, Soeda S. Inferior epigastric artery skin flaps without rectus abdominis muscle.  Br J Plast Surg. 1989;  42 645-648
• 19 Allen R J, Heitmann C. Perforator flaps—the history of evolution.  Handchir Mikrochir Plast Chir. 2002;  34 216-218
• 20 Blondeel P N, Van Landuyt K H, Monstrey S J et al.. The “Gent” consensus on perforator flap terminology: preliminary definitions.  Plast Reconstr Surg. 2003;  112 1378-1383 quiz 1383-1516 discussion 1384-1387