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Anatomically aberrant forearm arteries: an absent radial artery with co-dominant median and ulnar arteries
Anatomically aberrant forearm arteries
727
BritishJournalofPlasticSurgery(2001), 54 9 2001 The BritishAssociationof Plastic Surgeons doi:10.1054/bjps.2001.3706
Anatomically aberrant forearm arteries: an absent radial artery with co-dominant median and ulnar arteries C. J. W. Porter and C. G. M e l l o w * Plastic, Maxillofacial and Burns Unit, Hutt Hospital, Lower Hutt; and *Regional Centre for Reconstructive, Plastic, Maxillofacial and Hand Surgery, Middlemore Hospital, Auckland, New Zealand SUMMARY.
A radial-artery free flap was dissected f r o m a traumatically amputated forearm. D u r i n g dissection the arterial tree was found to be abnormal, with no radial artery. The arterial supply was based on c o - d o m i n a n t m e d i a n and ulnar arteries. This description raises issues regarding anatomical vascular aberrations w h e n planning f o r e a r m flaps. 9 2001 The British A s s o c i a t i o n o f Plastic Surgeons
Keywords: free flap, ulnar artery, m e d i a n artery, radial artery.
Case report A 25-year-old right-handed male was working in a tyre shredding bay when his right hand was caught in the tyre press conveyor mechanism, avulsing his right upper limb at the elbow joint. He presented within 1 h to the Emergency Department in good systemic condition with the amputated forearm chilled. There was evidence of crush injury to the forearm flexor compartments, but the skin was intact. The ulnar, median and radial nerves were attached to the forearm and extended 10-15 cm proximal to the level of amputation. The brachial artery stump was pulsating immediately proximal to the elbow. The distal triceps, biceps and brachialis were ragged and non-viable. The wound was contaminated with fragments of shredded tyre rubber. There had been no previous surgery or trauma to the limb. The decision was made that the limb was not salvageable due to the avulsion injury to the major nerves and the crush injury to multiple muscle groups. The aim was to maintain enough arm-stump length with robust skin tbr the application of a prosthesis. The patient was taken immediately to theatre, and the wound was debrided. The humerus was shortened 4 cm proximal to the elbow joint at the supracondylar level. The brachialis and triceps muscles were sutured together to provide soft tissue cover over the humerus. This left a skin deficit measuring 15 x 20 cm. The forearm was inspected and appeared suitable as a donor for a fasciocutaneous free flap. The forearm flap was designed from the elbow to the wrist circumferentially, based on the radial artery. A dorsal axial incision was required to dissect the flap and to change its form from a truncated cone to a sheet (20 cm long, with a width increasing from 12 cm at the wrist to 20 cm at the elbow). The dissection was started proximally at the avulsion level, where 3 cm of brachial artery was present above the level of the bifurcation. Dissection revealed an absent radial artery, with the brachial bifurcation at the cubital fossa giving rise to the ulnar artery and the common interosseous artery (Fig. 1). There was no evidence of a superficial radial artery. A median artery was traced from its origin at the anterior interosseous artery, coursing with the median nerve deep to the flexor digitorum superficialis and passing into the carpal tunnel. The calibres of the median and ulnar arteries were equivalent, and both these arteries were included in the flap. The anterior interosseous artery had a normal course and calibre. The dissection was not extended beyond the wrist. The 'radial artery' forearm flap design with this anatomical aberration brought into question the vascularity of this large
flap, especially of the skin dorsal to the preaxial border. There were 6.5 h of cold ischaemia and 2.5 h of warm ischaemia prior to anastomosis. The proximal brachial artery was anastomosed to the distal brachial artery, and the main proximal and distal venae comitantes were anastomosed. The entire flap was immediately well perfused, with fresh bleeding from the flap perimeter. The flap was not trimmed. The perfusion remained adequate while the flap was sutured to the defect; the postoperative course was uneventful. The patient was discharged from hospital 12 days after the injury, and had a prosthesis fitted at 3 months.
Discussion The median artery persists in between 4.4% and 8.3% of adults; I this is in addition to the presence of the radial and ulnar arteries. The absence of the radial artery has been described in the literature three times. 2~ All three of these cases describe a dominant anterior interosseous artery supplemented by an ulnar "artery of varying calibre and a small median artery. The combination of co-dominant median and ulnar arteries with an absent radial artery has not previously been described.
Figure 1--Volar aspect of the dissected forearm and the flap (the flap has been reversed, with the proximal aspect of the flap adjacent to the hand). The left sutures mark the brachial artery and the venae comitantes. The right sutures mark the median and ulnar arteries.
728
The reconstructive ideal in this case was to maintain enough limb length, covered with stable and sensate skin, for optimal fitting of a prosthesis. The options for skin cover were split-skin grafts or local or distant flaps. Sensation can be present with local flaps, pedicled flaps or free flaps with nerve anastomosis to a local cutaneous nerve. Free flaps without nerve reconstruction may develop partial, yet protective, sensation by the in-growth of peripheral cutaneous nerves. 5-7 Grafts and local flaps tend to be associated with delayed healing and rehabilitation. 8 The radial and ulnar artery forearm flaps have been widely described for local and distant reconstruction. 9-13 In this case, the forearm fasciocutaneous flap was raised from spare parts to fulfil the reconstructive ideal, although sensation could not be restored because there was no suitable cutaneous nerve present for anastomosis. Spare-parts surgery using a small pedicled fasciocutaneous flap based on a normal ulnar artery has been described to cover a mid-forearm amputation stump secondary to burns. 14 It is evident from this case that despite the absence of a radial artery in the forearm free flap, the entire forearm fasciocutaneous tissue can remain viable. We assume that the ulnar artery supplied the majority of the vascular territory of this flap. Anatomic anomalies of the upper-limb arterial supply in fasciocutaneous flaps have been described, affecting either the radial 15 or the ulnar artery, 16-18 with the superficial version of the latter being the most clinically important. The upper-limb arterial system is routinely tested preoperatively with Allen's test. This test is relatively crude and to exclude arterial anomalies more information is provided by Doppler ultrasound 8 or angiography. These investigations may be under used considering the presence of the superficial ulnar artery in 9.3% of upper limbs, ts The arterial supply to the circumferential forearm fasciocutaneous flap in this case depended on the ulnar and median arteries. To date, there has not been a description of this anatomical combination either in a flap or found incidentally. This case differs from most literature descriptions of forearm fasciocutaneous flaps as it is 'spare-parts' surgery, t9 Accordingly, there is no concern about a donor deficit, and the flap size is limited purely by the vascular territory. References 1. Henneberg M, George BJ. Possible secular trend in the incidence of an anatomical variant: median artery of the forearm. Am J Phys Anthropol 1995; 96: 329-34. 2. Charles JJ. A case of absence of the radial artery. J Anat Physiol 1894; 28: 449-50.
British Journal of Plastic Surgery 3. Kadanoff D, Balkansky G. Zwei F~ille mit seltenen Varietaten der Arterien der oberen Extremitat. Anat Anz Bd 1966; 118: 289-96. 4. Poteat WL. Report of a rare human variation: absence of the radial artery. Anat Rec 1986; 214: 89-95. 5. Close LG, Truelson JM, Milledge RA, Schweitzer C. Sensory recovery in noninnervated flaps used for oral cavity and oropharyngeal reconstruction. Arch Otolaryngol Head Neck Surg 1995; 121: 967-72. 6. Shindo ML, Sinha UK, Rice DH. Sensory recovery in noninnervated free flaps for head and neck reconstruction. Laryngoscope 1995; 105: 1290-3. 7. Vriens JPM, Acosta R, Soutar DS, Webster MHC. Recovery of sensation in the radial forearm free flap in oral reconstruction. Plast Reconstr Surg 1996; 98: 649-56. 8. Little JM, Zylstra PL, West J, May J. Circulatory patterns in the normal hand. Br J Surg 1973; 60: 652-5. 9. Glasson DW, Lovie MJ. The ulnar island flap in hand and forearm reconstruction. Br J Plast Surg 1988; 41: 349-53. 10. Lovie MJ, Duncan GM, Glasson DW. The ulnar artery forearm free flap. Br J Plast Surg 1984; 37: 486-92. 11. Song R, Gao Y, Song Y, Yu Y, Song Y. The forearm flap. Clin Plast Surg 1982; 9: 21-8. 12. Soutar DS, Scheker LR, Tanner NSB, McGregor IA. The radial forearm flap: a versatile method for intra-oral reconstruction. Br J Plast Surg 1983; 36: 1-8. 13. Soutar DS, Tanner NSB. The radial forearm flap in the management of soft tissue injuries of the hand. Br J Plast Surg 1984; 37:
18-26. 14. Turley CB, Clarke JA. Salvage of forearm skin as an ulnar artery flap in a severely burned upper limb. Burns 1991; 17: 56-8. 15. Small JO, Millar R. The radial artery forearm flap: an anomaly of the radial artery. Br J Plast Surg 1985; 38: 501-3. 16. Devansh. Superficial ulnar artery flap. Plast Reconstr Surg 1996; 97: 420-6. 17. Fatah MF, Nancarrow JD, Murray DS. Raising the radial artery forearm flap: the superficial ulnar artery 'trap'. Br J Plast Surg 1985; 38: 394-5. 18. Thoma A, Young JEM. The superficial ulnar artery 'trap' and the free forearm flap. Ann Plast Surg 1992; 28: 370-2. 19. Rees MJW, De Geus JJ. Immediate amputation stump coverage with forearm free flaps from the same limb. J Hand Surg 1988; 13A: 287-92.
The Authors Christopher J. W. Porter MB, ChB, Plastic Surgery Registrar Wellington Regional Plastic, Maxillofacial and Burns Unit, Hutt Hospital, High Street, Private Bag 31-907, Lower Hutt, New Zealand.
Carey G. Mellow MB, ChB, FRACS, Consultant Plastic Surgeon Regional Centre for Reconstructive, Plastic, Maxillofacial and Hand Surgery, Middlemore Hospital, Auckland, New Zealand. Correspondence to Dr Christopher Porter. Paper received 25 July 2000. Accepted 10 September 2001, after revision. Published online 22 October 2001.
727
BritishJournalofPlasticSurgery(2001), 54 9 2001 The BritishAssociationof Plastic Surgeons doi:10.1054/bjps.2001.3706
Anatomically aberrant forearm arteries: an absent radial artery with co-dominant median and ulnar arteries C. J. W. Porter and C. G. M e l l o w * Plastic, Maxillofacial and Burns Unit, Hutt Hospital, Lower Hutt; and *Regional Centre for Reconstructive, Plastic, Maxillofacial and Hand Surgery, Middlemore Hospital, Auckland, New Zealand SUMMARY.
A radial-artery free flap was dissected f r o m a traumatically amputated forearm. D u r i n g dissection the arterial tree was found to be abnormal, with no radial artery. The arterial supply was based on c o - d o m i n a n t m e d i a n and ulnar arteries. This description raises issues regarding anatomical vascular aberrations w h e n planning f o r e a r m flaps. 9 2001 The British A s s o c i a t i o n o f Plastic Surgeons
Keywords: free flap, ulnar artery, m e d i a n artery, radial artery.
Case report A 25-year-old right-handed male was working in a tyre shredding bay when his right hand was caught in the tyre press conveyor mechanism, avulsing his right upper limb at the elbow joint. He presented within 1 h to the Emergency Department in good systemic condition with the amputated forearm chilled. There was evidence of crush injury to the forearm flexor compartments, but the skin was intact. The ulnar, median and radial nerves were attached to the forearm and extended 10-15 cm proximal to the level of amputation. The brachial artery stump was pulsating immediately proximal to the elbow. The distal triceps, biceps and brachialis were ragged and non-viable. The wound was contaminated with fragments of shredded tyre rubber. There had been no previous surgery or trauma to the limb. The decision was made that the limb was not salvageable due to the avulsion injury to the major nerves and the crush injury to multiple muscle groups. The aim was to maintain enough arm-stump length with robust skin tbr the application of a prosthesis. The patient was taken immediately to theatre, and the wound was debrided. The humerus was shortened 4 cm proximal to the elbow joint at the supracondylar level. The brachialis and triceps muscles were sutured together to provide soft tissue cover over the humerus. This left a skin deficit measuring 15 x 20 cm. The forearm was inspected and appeared suitable as a donor for a fasciocutaneous free flap. The forearm flap was designed from the elbow to the wrist circumferentially, based on the radial artery. A dorsal axial incision was required to dissect the flap and to change its form from a truncated cone to a sheet (20 cm long, with a width increasing from 12 cm at the wrist to 20 cm at the elbow). The dissection was started proximally at the avulsion level, where 3 cm of brachial artery was present above the level of the bifurcation. Dissection revealed an absent radial artery, with the brachial bifurcation at the cubital fossa giving rise to the ulnar artery and the common interosseous artery (Fig. 1). There was no evidence of a superficial radial artery. A median artery was traced from its origin at the anterior interosseous artery, coursing with the median nerve deep to the flexor digitorum superficialis and passing into the carpal tunnel. The calibres of the median and ulnar arteries were equivalent, and both these arteries were included in the flap. The anterior interosseous artery had a normal course and calibre. The dissection was not extended beyond the wrist. The 'radial artery' forearm flap design with this anatomical aberration brought into question the vascularity of this large
flap, especially of the skin dorsal to the preaxial border. There were 6.5 h of cold ischaemia and 2.5 h of warm ischaemia prior to anastomosis. The proximal brachial artery was anastomosed to the distal brachial artery, and the main proximal and distal venae comitantes were anastomosed. The entire flap was immediately well perfused, with fresh bleeding from the flap perimeter. The flap was not trimmed. The perfusion remained adequate while the flap was sutured to the defect; the postoperative course was uneventful. The patient was discharged from hospital 12 days after the injury, and had a prosthesis fitted at 3 months.
Discussion The median artery persists in between 4.4% and 8.3% of adults; I this is in addition to the presence of the radial and ulnar arteries. The absence of the radial artery has been described in the literature three times. 2~ All three of these cases describe a dominant anterior interosseous artery supplemented by an ulnar "artery of varying calibre and a small median artery. The combination of co-dominant median and ulnar arteries with an absent radial artery has not previously been described.
Figure 1--Volar aspect of the dissected forearm and the flap (the flap has been reversed, with the proximal aspect of the flap adjacent to the hand). The left sutures mark the brachial artery and the venae comitantes. The right sutures mark the median and ulnar arteries.
728
The reconstructive ideal in this case was to maintain enough limb length, covered with stable and sensate skin, for optimal fitting of a prosthesis. The options for skin cover were split-skin grafts or local or distant flaps. Sensation can be present with local flaps, pedicled flaps or free flaps with nerve anastomosis to a local cutaneous nerve. Free flaps without nerve reconstruction may develop partial, yet protective, sensation by the in-growth of peripheral cutaneous nerves. 5-7 Grafts and local flaps tend to be associated with delayed healing and rehabilitation. 8 The radial and ulnar artery forearm flaps have been widely described for local and distant reconstruction. 9-13 In this case, the forearm fasciocutaneous flap was raised from spare parts to fulfil the reconstructive ideal, although sensation could not be restored because there was no suitable cutaneous nerve present for anastomosis. Spare-parts surgery using a small pedicled fasciocutaneous flap based on a normal ulnar artery has been described to cover a mid-forearm amputation stump secondary to burns. 14 It is evident from this case that despite the absence of a radial artery in the forearm free flap, the entire forearm fasciocutaneous tissue can remain viable. We assume that the ulnar artery supplied the majority of the vascular territory of this flap. Anatomic anomalies of the upper-limb arterial supply in fasciocutaneous flaps have been described, affecting either the radial 15 or the ulnar artery, 16-18 with the superficial version of the latter being the most clinically important. The upper-limb arterial system is routinely tested preoperatively with Allen's test. This test is relatively crude and to exclude arterial anomalies more information is provided by Doppler ultrasound 8 or angiography. These investigations may be under used considering the presence of the superficial ulnar artery in 9.3% of upper limbs, ts The arterial supply to the circumferential forearm fasciocutaneous flap in this case depended on the ulnar and median arteries. To date, there has not been a description of this anatomical combination either in a flap or found incidentally. This case differs from most literature descriptions of forearm fasciocutaneous flaps as it is 'spare-parts' surgery, t9 Accordingly, there is no concern about a donor deficit, and the flap size is limited purely by the vascular territory. References 1. Henneberg M, George BJ. Possible secular trend in the incidence of an anatomical variant: median artery of the forearm. Am J Phys Anthropol 1995; 96: 329-34. 2. Charles JJ. A case of absence of the radial artery. J Anat Physiol 1894; 28: 449-50.
British Journal of Plastic Surgery 3. Kadanoff D, Balkansky G. Zwei F~ille mit seltenen Varietaten der Arterien der oberen Extremitat. Anat Anz Bd 1966; 118: 289-96. 4. Poteat WL. Report of a rare human variation: absence of the radial artery. Anat Rec 1986; 214: 89-95. 5. Close LG, Truelson JM, Milledge RA, Schweitzer C. Sensory recovery in noninnervated flaps used for oral cavity and oropharyngeal reconstruction. Arch Otolaryngol Head Neck Surg 1995; 121: 967-72. 6. Shindo ML, Sinha UK, Rice DH. Sensory recovery in noninnervated free flaps for head and neck reconstruction. Laryngoscope 1995; 105: 1290-3. 7. Vriens JPM, Acosta R, Soutar DS, Webster MHC. Recovery of sensation in the radial forearm free flap in oral reconstruction. Plast Reconstr Surg 1996; 98: 649-56. 8. Little JM, Zylstra PL, West J, May J. Circulatory patterns in the normal hand. Br J Surg 1973; 60: 652-5. 9. Glasson DW, Lovie MJ. The ulnar island flap in hand and forearm reconstruction. Br J Plast Surg 1988; 41: 349-53. 10. Lovie MJ, Duncan GM, Glasson DW. The ulnar artery forearm free flap. Br J Plast Surg 1984; 37: 486-92. 11. Song R, Gao Y, Song Y, Yu Y, Song Y. The forearm flap. Clin Plast Surg 1982; 9: 21-8. 12. Soutar DS, Scheker LR, Tanner NSB, McGregor IA. The radial forearm flap: a versatile method for intra-oral reconstruction. Br J Plast Surg 1983; 36: 1-8. 13. Soutar DS, Tanner NSB. The radial forearm flap in the management of soft tissue injuries of the hand. Br J Plast Surg 1984; 37:
18-26. 14. Turley CB, Clarke JA. Salvage of forearm skin as an ulnar artery flap in a severely burned upper limb. Burns 1991; 17: 56-8. 15. Small JO, Millar R. The radial artery forearm flap: an anomaly of the radial artery. Br J Plast Surg 1985; 38: 501-3. 16. Devansh. Superficial ulnar artery flap. Plast Reconstr Surg 1996; 97: 420-6. 17. Fatah MF, Nancarrow JD, Murray DS. Raising the radial artery forearm flap: the superficial ulnar artery 'trap'. Br J Plast Surg 1985; 38: 394-5. 18. Thoma A, Young JEM. The superficial ulnar artery 'trap' and the free forearm flap. Ann Plast Surg 1992; 28: 370-2. 19. Rees MJW, De Geus JJ. Immediate amputation stump coverage with forearm free flaps from the same limb. J Hand Surg 1988; 13A: 287-92.
The Authors Christopher J. W. Porter MB, ChB, Plastic Surgery Registrar Wellington Regional Plastic, Maxillofacial and Burns Unit, Hutt Hospital, High Street, Private Bag 31-907, Lower Hutt, New Zealand.
Carey G. Mellow MB, ChB, FRACS, Consultant Plastic Surgeon Regional Centre for Reconstructive, Plastic, Maxillofacial and Hand Surgery, Middlemore Hospital, Auckland, New Zealand. Correspondence to Dr Christopher Porter. Paper received 25 July 2000. Accepted 10 September 2001, after revision. Published online 22 October 2001.