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flexor carpi radialis muscle flap for dorsal hand reconstruction: A clinical and cadaver study
The Distally Based Radial Artery/ Flexor Carpi Radialis Muscle Flap for Dorsal Hand Reconstruction: A Clinical and Cadaver Study Alexandrina S. Saulis, MD, Samir S. Sukkar, MD, Gregory A. Dumanian, MD, Chicago, IL Complex soft tissue defects of the hand often require vascularized tissue for protection and coverage of exposed underlying structures. Pedicled local flaps from the forearm are one reconstructive option, but its use is limited by relatively high donor-site problems, including a disagreeable forearm scar and potential division of superficial forearm nerves. We describe a pedicled local flap option--the distally based radial artery/flexor carpi radialis flap, which potentially decreases forearm donor-site morbidity while still providing for coverage of small hand soft tissue defects. Six cadaver forearm dissections were performed to confirm that the vascular supply to the middle and distal portion of the flexor carpi radialis comes off the radial artery. Four clinical cases are presented in which the flexor carpi radialis muscle based on the distal radial artery was used to cover complex wounds of the dorsum of the hand. We believe the lack of damage to the superficial sensory forearm nerves and the ease of flexor carpi radialis muscle flap elevation make this a versatile flap for small, complex, soft tissue defects of the hand. (J Hand Surg 2002;27A:1081-1086. Copyright © 2002 by the American Society for Surgery of the Hand.)
KeyWords:Radial
artery, flexor carpi radialis, flap.
Dorsal hand soft tissue injuries are often complicated wounds requiring vascularized tissue coverage for wound closure. Options for soft tissue coverage include local pedicled flaps, distant pedicled flaps such as the groin flap, and free tissue transfers. Use of each of these options is limited by donor-site From the Divisionof Plastic and ReconstructiveSurgery,Northwestern UniversityMedical School, Chicago, IL. Presented at The AmericanSociety for ReconstructiveMicrosurgery Meeting, Cancun, Mexico, January 12, 2002. Received for publication December 28, 2001: accepted in revised form July 10, 2002. No benefitsin any form have been receivedor will be receivedfrom a commercialparty related directly or indirectly to the subject of this article. Reprint requests: GregoryDumanian, MD, Division of Plastic and Reconstructive Surgery, NorthwesternUniversityMedical School, 675 N Saint Clair St, Suite 19-250, Chicago, IL 60611. Copyright © 2002 by the AmericanSocietyfor Surgery of the Hand 0363-5023/02/27A06-0026535.00/0 doi: 10.1053/jhsu.2002.35869
morbidities. For instance, groin flap use is hampered by the difficulty in postoperative hand elevation, c u m b e r s o m e positioning requirements, and the need for a second surgery. Free-tissue transfers require microsurgery, run the risk of vessel thrombosis, and have donor-site morbidities specific to the chosen flap. Pedicled local fasciocutaneous flaps have notable advantages of a 1-stage procedure limited to the damaged extremity and the lack of need for microsurgery. Major drawbacks of Jocal forearm flaps, however, include the need to divide superficial forearm nerves and unsightly donor site scars. The distally based or reversed fasciocutaneous radial artery forearm flap is probably the best-known local pedicled flap; however, reports from various groups have shown the high incidence of donor-site morbidity associated with this fasciocutaneous flap. These include skin-graft breakdown with flexor tendon expoThe Journal of Hand Surgery 1081
1082 Saulis, Sukkar, and Dumanian / Radial Artery/FCR Muscle Flap sure of the donor site in 6% to 50% of patients, reduced superficial nerve sensation in 18% to 50% of patients, cold intolerance in 14% to 38% of patients, and dissatisfaction with the aesthetic outcome in 14% to 29% of patients. 1-7 Variations of this flap have been attempted to minimize some of these very real and debilitating donor-site complications. An example is the pedicled or free radial artery-based fascial flap, which avoids the unaesthetic skin deftcir. s-l° Eliminating the skin component does avoid the wound healing and aesthetic complications, but it does little to preserve the superficial nerves to the volar forearm because many of the sensory nerves are closely adherent to the fascial layer. Furthermore, this fascial flap lacks the soft tissue layer to adequately fill in a soft tissue defect of the hand or gain adequate soft tissue coverage for later flap re-elevation should tendon grafting be necessary. This study proposes the use of a pedicled flexor carpi radialis (FCR) muscle flap, based on retrograde flow from the distal radial artery, with split thickness skin graft (STSG) coverage for wounds of the dotsum and palm of the hand. This flap potentially lessens donor-site morbidity because damage to the superficial nerves of the forearm can be avoided with careful dissection. The data from 6 cadaver arm dissections as well as the results of 4 clinical cases are presented in regard to this flap.
Materials and Methods
Anatomic Study Six cadaver forearms were dissected to confirm the neurovascular supply to the FCR muscle. Each extremity was amputated at the shoulder. A longitudinal incision over the volar forearm was used to expose the FCR muscle. Dissection entailed isolation of the muscle's origin and insertion, and its extramuscular nerve branches and vascular supply.
Clinical Study Retrospective chart reviews were performed for 4 clinical cases in which the reversed FCR muscle flap was used to cover complex dorsal hand defects. Reversed FCR muscle flap success was based on physician physical examination and donor-site complications on both physician physical examination and subjective patient complaints. The follow-up period was at least 3 months for each case.
Results
Anatomic Study The dissected cadaver muscle areas averaged 44.2 +_ 9.2 cm 2, composed of an average width of 3.0 +_ 0.5 cm and length of 14.7 __ 0.5 cm. The brachial artery served as the only blood supply to the most proximal aspect of the FCR muscle in all cases. This first large vascular branch off the brachial artery entered the muscle on average 2.4 _+ 1.4 cm distal to the medial epicondyle. An additional smaller branch off the anterior interosseus artery entering the proximal third of the muscle belly was noted in 1 dissected cadaver arm. The radial artery served as the primary blood supply to the middle and distal third of the FCR, sending off anywhere from 2 to 4 visible branches into the muscle belly. These branches were noted to enter the muscle anywhere from 4 to 13 cm distal to the medial epicondyle. These findings are consistent with previous anatomic studies, u
Clinical Study Four patients presented with complex defects of the dorsal hand that required vascular pedicle flap coverage. All patients considered for radial artery branch FCR flap coverage had Allen's testing of the vascular supply to the hand preoperatively to ensure the ulnar artery alone was adequate to provide blood flow to the fingers. The surgical procedures were done by using an upper-extremity tourniquet. Flexor carpi radialis muscle flap harvest was performed through a longitudinal volar forearm incision. Branches from the radial artery to the FCR muscle were preserved. The muscle was separated from surrounding musculature and divided proximally. The radial artery was divided proximal to the most proximal FCR muscle perforator. The divided end of the FCR muscle in all 4 cases showed bright-red bleeding after separation from the proximal blood supply. After inset into the dorsal hand defect, the muscle was covered with an STSG taken from the upper anterolateral thigh. Case 1. A 44-year-old woman suffered a chemotherapy extravasation injury to the dorsum of the right hand. The wound was observed for 3 months; there was no evidence of healing despite various local wound-care treatments. The patient was experiencing severe debilitating pain in the dorsal right hand during this period. She had a distally based radial artery/FCR muscle flap with STSG coverage. Her pain was alleviated within 1 week postopera-
The Journal of Hand Surgery / Vol. 27A No. 6 November 2002
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graft. Postoperatively, he has complete wound coverage and good right-hand function despite a moderately stiff fight thumb. He has no complaints of FCR donor-site cold intolerance or sensory disturbances. Case 3. A 48-year-old immunocompromised kidney transplant recipient presented with a large, fixed squamous cell tumor of the dorsum of the fight wrist. Excision of the mass resulted in exposure of the tendons of the first, second, and third extensor compartments. Wound coverage was successfully accomplished by using the distally based radial artery/ FCR muscle flap and STSG. Unfortunately, metastatic disease to the elbow, shoulder, and lungs subsequently developed. Case 4. A 54-year-old man with diabetes mellitus developed a necrotizing diabetic infection of the dorsum of his fight hand, requiring debridement of the dorsal skin, extensor retinaculum, extensor tendons, and a portion of the capitate. After obtaining local wound control with debridements and dressings, he underwent successful wound closure with the distally based radial artery/FCR muscle flap and an STSG.
Discussion Figure 1. Preoperative photograph of chemotherapy extravasation injury to the dorsum of the right hand of patient 1. This wound was painful and debilitating for the patient, with no evidence of healing after 3 months.
tively, and the wound subsequently healed without complications. She has no complaints of donor-site cold intolerance or sensory disturbances, and has regained her preinjury right hand function (Figs. 1-4). Case 2. A 69-year-old man presented with a Marjolin ulcer/squamous cell carcinoma of the dorsum of the fight hand fixed to the first and second metacarpals on initial examination. En bloc tumor resection with 1-cm margins resulted in removal of the extensor pollicis longus, both extensors to the index finger, the index and thumb metacarpals, and a large amount of skin. Thumb reconstruction employed the vascularized index finger phalanges for restoring bony stability and by covering the large soft tissue defect with a distally based radial artery/FCR muscle flap with STSG. The patient healed his wounds well with a small 2-cm 2 area of distal flap tip necrosis, which healed with local wound care and a repeat pinch skin
This study describes the use of the FCR muscle pedicled on the reverse radial artery as a muscle flap for complex defects of the hand. The cadaver dissections undertaken in 6 arms confirm the blood supply to the middle and distal third of the FCR as originating exclusively off the radial artery. This is con-
Figure 2. Intraoperative photograph of the FCR muscle and its middle and distal third vascular attachments to the radial artery of patient 1.
1084 Saulis, Sukkar, and Dumanian / Radial Artery/FCR Muscle Flap
Figure 3. Intraoperative photograph of patient 1. Note the large arc of rotation of the FCR muscle flap easily reaching the dorsum of the hand.
sistent with previous reports in the literature. 11 In all 4 clinical cases, after harvesting the FCR and detaching it from its proximal blood supply off the brachial artery, the proximal muscle end continued to bleed bright-red blood. This is dependent on a patent ulnar artery being able to maintain pulsatile blood flow within the hand. Preoperative assessment of hand blood flow with the Allen's test is mandatory. For patients with questionable Allen's test results, noninvasive testing with either pulse-volume recordings or with measurements of digital blood pressure with radial artery compression at the wrist is quite feasible. 12 In well-selected patients who maintain pulsatile digital blood flow despite radial artery occlusion at the wrist, we believe that the radial artery is expendable in regard to hand blood flow and hand function. 13 The FCR muscle can then be safely raised
and transposed as a pedicled muscle flap based on the retrograde radial artery blood supply. A major strength of this local pedicled flap is its arc of rotation. With dissection of the radial artery toward the radial styloid, the FCR muscle located in the proximal forearm can be easily be transferred to wounds on the dorsum of the hand. Although not performed in these patients, there is no reason why the flap could not cover a palmar or web space defect as well. Functionally, the FCR muscle assists in wrist stabilization and grip strength. Hand surgeons, however, have considered this muscle dispensable, using it for reconstructive hand procedures among which reconstruction of arthritis of the basal joint of the thumb is the most common. 14 Follow-up studies have shown that sacrificing the FCR results in no significant reduction in wrist stability or grip strength postoperatively. 15 We did not measure grip strength in these patients pre- and postoperatively because we believed the primary debilitating conditions of the involved hand requiring the muscle flap coverage precluded a valid pre- and postoperative comparison of grip strength. In comparison with other local pedicled flaps to the hand, we believe the preservation of superficial nerves is the chief advantage of the radial artery/FCR flap. Posttraumatic cold intolerance can occur in patients who have had neurovascular injury to the extremity. It is difficult to measure or to quantitate the degree of cold intolerance, 16 but patients seem to know when they have the condition. The radial forearm free-flap donor site has the complication of postoperative upper-extremity cold intolerance in the range of 14% to 3 8 % . 2.4 In comparison, we have not seen any nerve-related complications in patients who have had the pedicle flap transfer of the FCR with the radial artery. Specifically, these 4 patients have denied cold intolerance, neuroma-type forearm pain, or forearm numbness, but these are low patient numbers. Perhaps these radial artery/FCR flap patients can be lumped together with a larger group of patients who have had a similar dissection in terms of incision and postoperative changes in physiology. Harvest of the radial artery for coronary artery bypass grafting also involves a long forearm incision, muscle dissection, and removal of the radial artery. In a study performed by the senior author, 28 patients were carefully questioned and none complained of cold intolerance. 13 We believe that the pedicled FCR flap will have less nerve-related complications than the reversed radial forearm pedicled flap. The forearm is closed easily without tension and
The Journal of Hand Surgery / Vol. 27A No. 6 November 2002
1085
Figure 4. Postoperative photographs of patient 1. Note the smooth contour of the FCR flap inset site on the lateral view.
without skin grafts in comparison with the reversed radial forearm flap and the ulnar-sided transposition flap. Forearm aesthetics are excellent, with a single incision closed with an intracuticular stitch over the course of the radial artery. The flap harvest is fast and easy because the FCR lies directly adjacent to the radial artery and its branches to the middle and distal third of the muscle belly are easily identified. ~7 The wide arc of rotation has been previously mentioned. The muscle can be twisted and folded to take a variety of shapes, and it can be made to be as small as necessary. This is in comparison with fasciocutaneous flaps, which thinning and trimming can adversely affect flap vascularity. We emphasize that this flap should be used for smaller as opposed to larger defects, and more for radial-sided and central hand defects than for ulnar-sided defects. One should not plan to use this flap if the surface area of the defect is anticipated to be 10-20 cm 2, depending on wound shape and location. There may be a theoretic advantage to the use of a muscle flap to cover a contaminated wound instead of a similar fasciocutaneous flap for bacteria clearance. ~s19 Finally, when compared with a radial artery/forearm fascia flap, there is increased flap thickness. This may come into play at the time of an anticipated flap elevation and second-stage tendon reconstruction.
We propose the distally based radial artery FCR muscle flap for reconstruction of dorsal hand soft tissue defects as a useful flap option in many situations for the previously discussed reasons. We have not encountered any donor-site morbidity in these 4 cases.
References 1. Soutar DS, Tanner NS. The radial forearm flap in the management of soft tissue injuries of the hand. Br J Plast Surg 1984;37:18-26. 2. Timmons MJ, Missotten FEM, Poole MD, Davies DM. Complications of radial forearm flap donor sites. Br J Plast Surg 1986;39:176-178. 3. Richardson D, Fisher SE, Vaughan ED, Brown JS. Radial forearm flap donor-site complications and morbidity: a prospective study. Plast Reconstr Surg 1997;99:109-115. 4. Suominen S, Ahovuo J, Asko-Seljavaara S. Donor site morbidity of radial forearm flaps. A clinical and ulu-asonographic evaluation. Scand J Plast Reconstr Hand Surg 1996;30:57-61. 5. Boorman JG, Brown JA, Sykes PJ. Morbidity in the forearm flap donor arm. Br J Plast Surg 1987;40:207-212. 6. Bardsley AF, Soutar DS, Elliot D, Batchelor AG. Reducing morbidity in the radial forearm flap donor site. Plast Reconstr Surg 1990;86:287-292. 7. Swanson E, Boyd JB, Manktelow RT. The radial forearm flap: reconstructive applications and donor-site defects in 35 patients. Plast Reconstr Surg 1990;85:258-266.
1086
Saulis, Sukkar, and Dumanian / Radial Artery/FCR Muscle Flap
8. Ismail TIA. The free fascial forearm flap. Microsurgery 1989;10:155-160. 9. Jin Y, Guan W, Shi T, Quian Y, Xu L, Chang T. Reversed island forearm fascial flap in hand surgery. Ann Plast Surg 1985; 15:340-347. 10. Adani R, Tarallo L, Marcoccio I. Island radial artery fasciotendinous flap for dorsal hand reconstruction. Ann Plast Surg 2001;47:83-85. 11. Revol MP, Lantieri L, Loy S, Gu6rin-Surville H, Vascular anatomy of the forearm muscles: a study of 50 dissections. Plast Reconstr Surg 1991;88:1026-1033. 12. Dumanian GA, Segalman K, Buehner JW, Koontz CL, Hendrickson MF, Wilgis EFS. Analysis of digital pulsevolume recordings with radial and ulnar artery compression. Plast Reconstr Surg 1998;102:1993-1998. 13. Dumanian GA, Segalman K, Mispireta LA, Walsh JA, Hendrickson MF, Wilgis EFS. Radial artery use in bypass grafting does not change digital blood flow or hand function. Ann Thorac Surg 1998:65:1284-1287.
14. Burton RI, Wilgis EFS. Ligament reconstruction and tendon interposition for an osteoarthritic basal joint of the thumb. Strategies Orthop Surg 1991;10:1-16. 15. Tomaino MM, Coleman K. Use of the entire width of the flexor carpi radialis tendon for the ligament reconstruction tendon interposition arthroplasty does not impair wrist function. Am J Orthop 2000;29:283-284. 16. Lithell M, Backman C, Nystrom A. Pattern recognition in postt~aumatic cold intolerance. J Hand Surg 1997;22B:783-787. 17. Hamilton RB, Proudman TW. The radial forearm--flexor carpi radialis myocutaneous flap: a case report. Br J Plast Surg 1992:45:322-323. 18. Gosain A, Chang N, Mathes S, Hunt TK, Vasconez L. A study of the relationship between blood flow and bacterial inoculation in musculocutaneous and fasciocutaneous flaps. Plast Reconstr Surg 1990;86:1152-1162. 19. Calderon W, Chang N, Mathes SJ. Comparison of the effect of bacterial inoculation in musculocutaneous and fasciocutaneous flaps. Plast Reconstr Surg 1986;77:785-792.
KeyWords:Radial
artery, flexor carpi radialis, flap.
Dorsal hand soft tissue injuries are often complicated wounds requiring vascularized tissue coverage for wound closure. Options for soft tissue coverage include local pedicled flaps, distant pedicled flaps such as the groin flap, and free tissue transfers. Use of each of these options is limited by donor-site From the Divisionof Plastic and ReconstructiveSurgery,Northwestern UniversityMedical School, Chicago, IL. Presented at The AmericanSociety for ReconstructiveMicrosurgery Meeting, Cancun, Mexico, January 12, 2002. Received for publication December 28, 2001: accepted in revised form July 10, 2002. No benefitsin any form have been receivedor will be receivedfrom a commercialparty related directly or indirectly to the subject of this article. Reprint requests: GregoryDumanian, MD, Division of Plastic and Reconstructive Surgery, NorthwesternUniversityMedical School, 675 N Saint Clair St, Suite 19-250, Chicago, IL 60611. Copyright © 2002 by the AmericanSocietyfor Surgery of the Hand 0363-5023/02/27A06-0026535.00/0 doi: 10.1053/jhsu.2002.35869
morbidities. For instance, groin flap use is hampered by the difficulty in postoperative hand elevation, c u m b e r s o m e positioning requirements, and the need for a second surgery. Free-tissue transfers require microsurgery, run the risk of vessel thrombosis, and have donor-site morbidities specific to the chosen flap. Pedicled local fasciocutaneous flaps have notable advantages of a 1-stage procedure limited to the damaged extremity and the lack of need for microsurgery. Major drawbacks of Jocal forearm flaps, however, include the need to divide superficial forearm nerves and unsightly donor site scars. The distally based or reversed fasciocutaneous radial artery forearm flap is probably the best-known local pedicled flap; however, reports from various groups have shown the high incidence of donor-site morbidity associated with this fasciocutaneous flap. These include skin-graft breakdown with flexor tendon expoThe Journal of Hand Surgery 1081
1082 Saulis, Sukkar, and Dumanian / Radial Artery/FCR Muscle Flap sure of the donor site in 6% to 50% of patients, reduced superficial nerve sensation in 18% to 50% of patients, cold intolerance in 14% to 38% of patients, and dissatisfaction with the aesthetic outcome in 14% to 29% of patients. 1-7 Variations of this flap have been attempted to minimize some of these very real and debilitating donor-site complications. An example is the pedicled or free radial artery-based fascial flap, which avoids the unaesthetic skin deftcir. s-l° Eliminating the skin component does avoid the wound healing and aesthetic complications, but it does little to preserve the superficial nerves to the volar forearm because many of the sensory nerves are closely adherent to the fascial layer. Furthermore, this fascial flap lacks the soft tissue layer to adequately fill in a soft tissue defect of the hand or gain adequate soft tissue coverage for later flap re-elevation should tendon grafting be necessary. This study proposes the use of a pedicled flexor carpi radialis (FCR) muscle flap, based on retrograde flow from the distal radial artery, with split thickness skin graft (STSG) coverage for wounds of the dotsum and palm of the hand. This flap potentially lessens donor-site morbidity because damage to the superficial nerves of the forearm can be avoided with careful dissection. The data from 6 cadaver arm dissections as well as the results of 4 clinical cases are presented in regard to this flap.
Materials and Methods
Anatomic Study Six cadaver forearms were dissected to confirm the neurovascular supply to the FCR muscle. Each extremity was amputated at the shoulder. A longitudinal incision over the volar forearm was used to expose the FCR muscle. Dissection entailed isolation of the muscle's origin and insertion, and its extramuscular nerve branches and vascular supply.
Clinical Study Retrospective chart reviews were performed for 4 clinical cases in which the reversed FCR muscle flap was used to cover complex dorsal hand defects. Reversed FCR muscle flap success was based on physician physical examination and donor-site complications on both physician physical examination and subjective patient complaints. The follow-up period was at least 3 months for each case.
Results
Anatomic Study The dissected cadaver muscle areas averaged 44.2 +_ 9.2 cm 2, composed of an average width of 3.0 +_ 0.5 cm and length of 14.7 __ 0.5 cm. The brachial artery served as the only blood supply to the most proximal aspect of the FCR muscle in all cases. This first large vascular branch off the brachial artery entered the muscle on average 2.4 _+ 1.4 cm distal to the medial epicondyle. An additional smaller branch off the anterior interosseus artery entering the proximal third of the muscle belly was noted in 1 dissected cadaver arm. The radial artery served as the primary blood supply to the middle and distal third of the FCR, sending off anywhere from 2 to 4 visible branches into the muscle belly. These branches were noted to enter the muscle anywhere from 4 to 13 cm distal to the medial epicondyle. These findings are consistent with previous anatomic studies, u
Clinical Study Four patients presented with complex defects of the dorsal hand that required vascular pedicle flap coverage. All patients considered for radial artery branch FCR flap coverage had Allen's testing of the vascular supply to the hand preoperatively to ensure the ulnar artery alone was adequate to provide blood flow to the fingers. The surgical procedures were done by using an upper-extremity tourniquet. Flexor carpi radialis muscle flap harvest was performed through a longitudinal volar forearm incision. Branches from the radial artery to the FCR muscle were preserved. The muscle was separated from surrounding musculature and divided proximally. The radial artery was divided proximal to the most proximal FCR muscle perforator. The divided end of the FCR muscle in all 4 cases showed bright-red bleeding after separation from the proximal blood supply. After inset into the dorsal hand defect, the muscle was covered with an STSG taken from the upper anterolateral thigh. Case 1. A 44-year-old woman suffered a chemotherapy extravasation injury to the dorsum of the right hand. The wound was observed for 3 months; there was no evidence of healing despite various local wound-care treatments. The patient was experiencing severe debilitating pain in the dorsal right hand during this period. She had a distally based radial artery/FCR muscle flap with STSG coverage. Her pain was alleviated within 1 week postopera-
The Journal of Hand Surgery / Vol. 27A No. 6 November 2002
1083
graft. Postoperatively, he has complete wound coverage and good right-hand function despite a moderately stiff fight thumb. He has no complaints of FCR donor-site cold intolerance or sensory disturbances. Case 3. A 48-year-old immunocompromised kidney transplant recipient presented with a large, fixed squamous cell tumor of the dorsum of the fight wrist. Excision of the mass resulted in exposure of the tendons of the first, second, and third extensor compartments. Wound coverage was successfully accomplished by using the distally based radial artery/ FCR muscle flap and STSG. Unfortunately, metastatic disease to the elbow, shoulder, and lungs subsequently developed. Case 4. A 54-year-old man with diabetes mellitus developed a necrotizing diabetic infection of the dorsum of his fight hand, requiring debridement of the dorsal skin, extensor retinaculum, extensor tendons, and a portion of the capitate. After obtaining local wound control with debridements and dressings, he underwent successful wound closure with the distally based radial artery/FCR muscle flap and an STSG.
Discussion Figure 1. Preoperative photograph of chemotherapy extravasation injury to the dorsum of the right hand of patient 1. This wound was painful and debilitating for the patient, with no evidence of healing after 3 months.
tively, and the wound subsequently healed without complications. She has no complaints of donor-site cold intolerance or sensory disturbances, and has regained her preinjury right hand function (Figs. 1-4). Case 2. A 69-year-old man presented with a Marjolin ulcer/squamous cell carcinoma of the dorsum of the fight hand fixed to the first and second metacarpals on initial examination. En bloc tumor resection with 1-cm margins resulted in removal of the extensor pollicis longus, both extensors to the index finger, the index and thumb metacarpals, and a large amount of skin. Thumb reconstruction employed the vascularized index finger phalanges for restoring bony stability and by covering the large soft tissue defect with a distally based radial artery/FCR muscle flap with STSG. The patient healed his wounds well with a small 2-cm 2 area of distal flap tip necrosis, which healed with local wound care and a repeat pinch skin
This study describes the use of the FCR muscle pedicled on the reverse radial artery as a muscle flap for complex defects of the hand. The cadaver dissections undertaken in 6 arms confirm the blood supply to the middle and distal third of the FCR as originating exclusively off the radial artery. This is con-
Figure 2. Intraoperative photograph of the FCR muscle and its middle and distal third vascular attachments to the radial artery of patient 1.
1084 Saulis, Sukkar, and Dumanian / Radial Artery/FCR Muscle Flap
Figure 3. Intraoperative photograph of patient 1. Note the large arc of rotation of the FCR muscle flap easily reaching the dorsum of the hand.
sistent with previous reports in the literature. 11 In all 4 clinical cases, after harvesting the FCR and detaching it from its proximal blood supply off the brachial artery, the proximal muscle end continued to bleed bright-red blood. This is dependent on a patent ulnar artery being able to maintain pulsatile blood flow within the hand. Preoperative assessment of hand blood flow with the Allen's test is mandatory. For patients with questionable Allen's test results, noninvasive testing with either pulse-volume recordings or with measurements of digital blood pressure with radial artery compression at the wrist is quite feasible. 12 In well-selected patients who maintain pulsatile digital blood flow despite radial artery occlusion at the wrist, we believe that the radial artery is expendable in regard to hand blood flow and hand function. 13 The FCR muscle can then be safely raised
and transposed as a pedicled muscle flap based on the retrograde radial artery blood supply. A major strength of this local pedicled flap is its arc of rotation. With dissection of the radial artery toward the radial styloid, the FCR muscle located in the proximal forearm can be easily be transferred to wounds on the dorsum of the hand. Although not performed in these patients, there is no reason why the flap could not cover a palmar or web space defect as well. Functionally, the FCR muscle assists in wrist stabilization and grip strength. Hand surgeons, however, have considered this muscle dispensable, using it for reconstructive hand procedures among which reconstruction of arthritis of the basal joint of the thumb is the most common. 14 Follow-up studies have shown that sacrificing the FCR results in no significant reduction in wrist stability or grip strength postoperatively. 15 We did not measure grip strength in these patients pre- and postoperatively because we believed the primary debilitating conditions of the involved hand requiring the muscle flap coverage precluded a valid pre- and postoperative comparison of grip strength. In comparison with other local pedicled flaps to the hand, we believe the preservation of superficial nerves is the chief advantage of the radial artery/FCR flap. Posttraumatic cold intolerance can occur in patients who have had neurovascular injury to the extremity. It is difficult to measure or to quantitate the degree of cold intolerance, 16 but patients seem to know when they have the condition. The radial forearm free-flap donor site has the complication of postoperative upper-extremity cold intolerance in the range of 14% to 3 8 % . 2.4 In comparison, we have not seen any nerve-related complications in patients who have had the pedicle flap transfer of the FCR with the radial artery. Specifically, these 4 patients have denied cold intolerance, neuroma-type forearm pain, or forearm numbness, but these are low patient numbers. Perhaps these radial artery/FCR flap patients can be lumped together with a larger group of patients who have had a similar dissection in terms of incision and postoperative changes in physiology. Harvest of the radial artery for coronary artery bypass grafting also involves a long forearm incision, muscle dissection, and removal of the radial artery. In a study performed by the senior author, 28 patients were carefully questioned and none complained of cold intolerance. 13 We believe that the pedicled FCR flap will have less nerve-related complications than the reversed radial forearm pedicled flap. The forearm is closed easily without tension and
The Journal of Hand Surgery / Vol. 27A No. 6 November 2002
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Figure 4. Postoperative photographs of patient 1. Note the smooth contour of the FCR flap inset site on the lateral view.
without skin grafts in comparison with the reversed radial forearm flap and the ulnar-sided transposition flap. Forearm aesthetics are excellent, with a single incision closed with an intracuticular stitch over the course of the radial artery. The flap harvest is fast and easy because the FCR lies directly adjacent to the radial artery and its branches to the middle and distal third of the muscle belly are easily identified. ~7 The wide arc of rotation has been previously mentioned. The muscle can be twisted and folded to take a variety of shapes, and it can be made to be as small as necessary. This is in comparison with fasciocutaneous flaps, which thinning and trimming can adversely affect flap vascularity. We emphasize that this flap should be used for smaller as opposed to larger defects, and more for radial-sided and central hand defects than for ulnar-sided defects. One should not plan to use this flap if the surface area of the defect is anticipated to be 10-20 cm 2, depending on wound shape and location. There may be a theoretic advantage to the use of a muscle flap to cover a contaminated wound instead of a similar fasciocutaneous flap for bacteria clearance. ~s19 Finally, when compared with a radial artery/forearm fascia flap, there is increased flap thickness. This may come into play at the time of an anticipated flap elevation and second-stage tendon reconstruction.
We propose the distally based radial artery FCR muscle flap for reconstruction of dorsal hand soft tissue defects as a useful flap option in many situations for the previously discussed reasons. We have not encountered any donor-site morbidity in these 4 cases.
References 1. Soutar DS, Tanner NS. The radial forearm flap in the management of soft tissue injuries of the hand. Br J Plast Surg 1984;37:18-26. 2. Timmons MJ, Missotten FEM, Poole MD, Davies DM. Complications of radial forearm flap donor sites. Br J Plast Surg 1986;39:176-178. 3. Richardson D, Fisher SE, Vaughan ED, Brown JS. Radial forearm flap donor-site complications and morbidity: a prospective study. Plast Reconstr Surg 1997;99:109-115. 4. Suominen S, Ahovuo J, Asko-Seljavaara S. Donor site morbidity of radial forearm flaps. A clinical and ulu-asonographic evaluation. Scand J Plast Reconstr Hand Surg 1996;30:57-61. 5. Boorman JG, Brown JA, Sykes PJ. Morbidity in the forearm flap donor arm. Br J Plast Surg 1987;40:207-212. 6. Bardsley AF, Soutar DS, Elliot D, Batchelor AG. Reducing morbidity in the radial forearm flap donor site. Plast Reconstr Surg 1990;86:287-292. 7. Swanson E, Boyd JB, Manktelow RT. The radial forearm flap: reconstructive applications and donor-site defects in 35 patients. Plast Reconstr Surg 1990;85:258-266.
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Saulis, Sukkar, and Dumanian / Radial Artery/FCR Muscle Flap
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14. Burton RI, Wilgis EFS. Ligament reconstruction and tendon interposition for an osteoarthritic basal joint of the thumb. Strategies Orthop Surg 1991;10:1-16. 15. Tomaino MM, Coleman K. Use of the entire width of the flexor carpi radialis tendon for the ligament reconstruction tendon interposition arthroplasty does not impair wrist function. Am J Orthop 2000;29:283-284. 16. Lithell M, Backman C, Nystrom A. Pattern recognition in postt~aumatic cold intolerance. J Hand Surg 1997;22B:783-787. 17. Hamilton RB, Proudman TW. The radial forearm--flexor carpi radialis myocutaneous flap: a case report. Br J Plast Surg 1992:45:322-323. 18. Gosain A, Chang N, Mathes S, Hunt TK, Vasconez L. A study of the relationship between blood flow and bacterial inoculation in musculocutaneous and fasciocutaneous flaps. Plast Reconstr Surg 1990;86:1152-1162. 19. Calderon W, Chang N, Mathes SJ. Comparison of the effect of bacterial inoculation in musculocutaneous and fasciocutaneous flaps. Plast Reconstr Surg 1986;77:785-792.