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Reverse posterior interosseous flap for defects of the dorsal ulnar wrist using previously burned and recently grafted skin
burns 42 (2016) e24–e30
Available online at www.sciencedirect.com
ScienceDirect journal homepage: www.elsevier.com/locate/burns
Case report
Reverse posterior interosseous flap for defects of the dorsal ulnar wrist using previously burned and recently grafted skin Joseph M. Baylan a, J. Alan Chambers c, Neil McMullin b, John L. Fletcher b, Indranil Sinha d, Jonathan Lundy b, Booker T. King b, Rodney K. Chan b,* a
Department of Surgery, Scott and White Hospital Systems, Temple, TX, United States Clinical Division and Burn Center, US Army Institute of Surgical Research, 3650 Chambers Pass, Fort Sam Houston, TX, United States c Walter Reed National Military Medical Center, Washington, DC, United States d Division of Plastic Surgery, Brigham and Women’s Hospital, Boston, MA, United States b
article info
abstract
Article history:
Background: In the severely burned patient, coverage of exposed bone in the dorsal ulnar
Accepted 29 June 2015
wrist can be a difficult problem. This is especially challenging in patients with a high
Keywords:
previously burned and/or recently grafted skin as flaps is an option. It has been postulated
Hand burn
that use of previously burned skin can result in higher rates of local or distant flap failures.
percentage total body surface area (TBSA) where donor flaps can be scarce. The use of
Posterior interosseous artery flap
The reverse posterior interosseous flap (PIF) is an axial flap, based on the retrograde posterior interosseous artery, to provide coverage of the hand. Here we describe utilization of the PIF, using previously burned and/or recently grafted skin for coverage of dorsal ulnar wrist defects. Methods: This is a case series of three patients, with extensive burns (range 35–83%TBSA), where defects of the dorsal ulnar wrist necessitated coverage. Each patient underwent PIF(s) utilizing previously burned and/or grafted skin, all within three months after their initial burn event. Results: Case 1: 28 year old male who suffered 35% TBSA via blast mechanism developed a chronic open wound over the dorsal ulnar wrist with exposed tendon. The patient successfully underwent a left PIF using previously grafted skin. Case 2: 23 year old male with 83% TBSA. Bilateral ulnar styloids were exposed. PIFs were performed bilaterally, using previously burned and recently grafted skin. Coverage was successful but received leech therapy post-operatively for venous congestion. Case 3: 37 year old male with 52% TBSA, with the most severe burns isolated to his bilateral upper extremities; the ulnar head was exposed. The posterior interroseous artery was explored and PIF was attempted, but there was no retrograde flow in the distal artery due to a deeper injury than previously recognized. The patient ultimately underwent a pedicled abdominal flap for coverage.
* Corresponding author at: Clinical Division and Burn Center, U.S. Army Institute of Surgical Research, 3650 Chambers Pass, Fort Sam Houston, TX 78234-6315, United States. Tel.: +1 210 539 8511; fax: +1 210 916 9148. E-mail address: [email protected] (R.K. Chan). http://dx.doi.org/10.1016/j.burns.2015.06.020 0305-4179/# 2015 Elsevier Ltd and ISBI. All rights reserved.
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Conclusions: Defects of the distal ulnar wrist after deep and extensive burns can be problematic. Use of the reverse PIF using previously burned skin, even those that has just been recently grafted is a viable option for this difficult patient population. However, it may not be possible in all patients. Vigilance and early intervention for post-operative venous congestion are important. # 2015 Elsevier Ltd and ISBI. All rights reserved.
1.
Introduction
Soft tissue coverage of upper extremity defects is challenging, especially when bone, tendons or joints are exposed. The upper extremities are the most common areas of burn involvement [1]. The dorsal ulnar at the level of the wrist is particularly prone to exposure as the amount of native soft tissue coverage is thin. This problem is compounded in burn patients where limited donor options and contiguous areas of burn involvement often exist. Options for flap coverage of wounds in this area includes radial forearm or ulnar artery pedicled flaps [2,3]. Both however may have significant donor site morbidity [4]. Additionally, pedicled groin or abdominal flaps offer a reliable option for reconstruction, but require multiple operations and can result in significant hand stiffness [5]. The reversed posterior interosseous artery flap (rPIF) represents a viable option as well. In addition, the use of previously burned and recently grafted skin as flaps has been reported in the literature but its use has been limited [6]. Several authors have postulated that use of burned skin can result in higher rates of local or distant flap failures due to altered microcirculation within the subcutaneous tissue [7]. The (rPIF) is a fasciocutaneous flap, based on retrograde flow into the posterior interosseous artery from its distal anastomosis to the anterior interosseous artery [8]. The rPIF allows coverage of the dorsal wrist, thumb, hand, and first webspace [9]. First described as a reverse flow pedicled flap in 1986 [10,11], the advantages of the rPIF include proximity to the hand, minimal injury to the main lymphatics and vessels of the forearm and the potential to primarily close the donor; depending on skin paddle size [6]. Disadvantages include variable perforator anatomy and possible disruption of the anterior interosseous artery anastomosis. Here we describe our experience using previously burned skin in reverse posterior interosseous flaps for coverage of dorsal ulnar wrist defects.
which exists as a branch of the common interosseous artery (CIA) and most often possesses a distal anastomosis with the anterior interosseous artery (AIA). Surgically the PIA is encountered proximally as it emerges from under the supinator muscle and descends on the proximal muscle bellies of abductor pollicus longus (APL) and extensor pollicis longus (EPL) muscles (Fig. 1). The PIA to AIA anastomotic branch dives deep to the extensor indicis muscle penetrating the interosseous membrane. Most commonly the PIA supports three branches supplying the supinator, APL and EPL muscles. Strauch and Yu report absence of the AIA to PIA anastomotic branch (2–3%) or a robust retrograde PIA without a large recurrent AIA branch (5.7%) [12]. The consequences of these variations are obvious and preclude the use of the rPIF. Typically the posterior interosseous nerve (PIN) lies deep and lateral to the PIA with the extensor carpi ulnaris (ECU) motor branch crossing deep to the PIA. There are, however described variants where the ECU motor branch of the PIN crosses superficial to the PIA.
2.2.
Surgical technique
A review of the senior author’s personal records identified three patients, with thermal injury mechanism (range 35– 83%TBSA), who underwent four rPIF procedures for soft-tissue defects exposing the dorsal ulnar styloid. Each patient underwent rPIF utilizing previously burned and grafted skin, all within three months after their initial burn event and 6–10 weeks following attempted grafting.
A line is drawn from the lateral epicondyle to the distal radioulnar joint while the arm is in resting elbow flexion, corresponding to the axis of the PIA. Construction of the skin paddle is completed along this axis and is based from the middle third of the forearm so as to include sufficient pedicle length for rotation. This flap may be designed as an island pedicle flap or with the inclusion of a skin bridge. Preoperative doppler ultrasound aids in detection of perforators. The flap is raised from the ulnar border incorporating the deep fascia in the flap. Caution is warranted as the surgeon’s dissection reaches the radial border of the extensor carpi ulnaris (ECU) to include the fascial attachments from the pedicle to the fascia. Once the pedicle is identified, the radial incision is made and the muscle belly of the extensor digiti minimi (EDM) identified. EDM is then retracted radially, the ECU ulnarly and attention is turned to identifying and preserving the PIN to include its ECU motor branch proximally. The PIA is dissected, taking care capture all perforators feeding the skin paddle. The proximal PIA and venae comitantes may be ligated and divided early to facilitate flap dissection. Once sufficient pedicle length is achieved, the flap is rotated into place, and the resulting donor defect is covered with splitthickness skin graft. Splint to keep the wrist in slight extension is advisable but it is important to avoid pressure on the pedicle.
2.1.
2.3.
2.
Methods
Relevant anatomy
As has been previously described [8] the rPIF is based on retrograde flow within the posterior interosseous artery (PIA)
Flap monitoring
Once inset, the flap can be monitored similarly to any pedicled flap. Congestion or insufficiency will manifest with
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Fig. 1 – Cross-sectional view of the wrist. Red contour indicates the location of PIA flap, which includes the fascia overlying the ECU and ED. Location of the interroseous membrane (IM) and the Anterior Interroseous Artery (AIA) are noted.
changes to the flap color and turgor, even in the presence of burned skin. A change in the appearance of the flap could signify vascular compromise and warrants exploration of the vascular pedicle.
3.
Results
3.1.
Case 1
28 year old male with 35% TBSA degree burns to face, bilateral upper extremities, back, buttocks, and posterior lower extremities via blast mechanism. Multiple operations to the dorsal ulnar wrist including a local flap failed. A chronic open wound developed over the dorsal ulnar wrist with exposed FCU tendon. The patient underwent a left reverse PIF using previously burned and grafted skin. Skin graft was applied to flap donor site. Post-operative stay was uneventful and flap was successful (Fig. 2).
3.2.
Case 2
23 year old male with 83% TBSA to face, trunk, upper and lower extremities secondary to flame burn with exposed ulnar styloids bilaterally. During his initial hospitalization, bilateral reverse PIFs were performed to provide coverage to his dorsal ulnar wrist defects using previously burned and recently grafted skin. Donor sites were grafted. Leech therapy was prescribed post-operatively for venous congestion but flap coverage was ultimately viable and successful (Fig. 3).
3.3.
Case 3
37 year old male with 52% TBSA to trunk, upper extremities, face, and thighs via flame burn. Multiple debridements and grafting procedures including reverse radial forearm flap to cover exposed wrist tendons on the left. However, a distal ulnar wrist remained with exposed bone. Left reverse PIF was attempted. Intraoperatively, the course of the PIA was identified by Doppler ultrasound, though the signal was admittedly faint. We proceeded with flap dissection and division of the distal pedicle. At that point, it became evident that there was no communication with the anterior interosseous artery. The patient ultimately underwent successful pedicled abdominal flap for coverage (Fig. 4).
4.
Discussion
Defects of the dorsal ulnar wrist present a challenging yet common problem in upper extremity burns. Use of previously burned and recently grafted skin as flaps when the deep fascia is intact is an attractive option with minimal donor site morbidity. We have described the use of a reverse posterior interroseous artery flap in previously burned and recently grafted skin for exposed ulnar styloid. The use of previously burned skin as flaps is not a novel concept. Most burn contracture releases using Z-plasties or transfer of adjacent tissue successfully incorporate some component of previously burned or grafted skin and represent the workhorse of burn reconstructive surgery [2]. However, the use of previously burned skin as island or pedicle flaps has not
burns 42 (2016) e24–e30
e27
Fig. 2 – (Case 1) Unilateral exposed dorsal ulnar styloid is observed. Preoperative markings indicate the proposed location of the PIA and ECU and EDM muscle bellies (A). A skin bridge is left in place to prevent venous congestion. The flap has been inset and seen intra-operatively (B). The donor site has been covered with a split thickness skin graft, and there is no evidence of venous congestion (C). Long term post-operative follow up with minimal morbidity and essentially no additional scars (D).
been met with similar level of enthusiasm. Pribaz and Pelham published the first large series using previously burned skin in 40 fasciocutaneous flaps. Among them, six posterior interosseous flaps were reported though most were performed in the non-acute period to resurface contractures of the first webspace [13]. In their discussion, Pribaz and Pelham emphasized the importance of fully harvesting the fascia along with the desired soft-tissues to provide the most durable vascular supply to the rotated tissues [13]. Hallock et al. describes initial flaps using burned skin were raised with failure to recognize importance of deep fascia in protecting circulation to the integument [14]. Fasciocutaneous flaps are specifically relevant to the use of previously burned skin since perforators to the deep fascia usually are found deep in the intermuscular septa and are protected even in deep burns [14]. It is imperative to raise the previously burned or skin grafted flap with its underlying fascia in order to capture its blood supply [15]. The rPIF was first described by in 1986 and can be utilized as a composite carrying muscle, tendon, or ulnar bone if indicated [10]. Based on the retrograde PIA, it is an option to cover defects of the wrist and hand. Because of its variable vascular anatomy [16], however, it has not gained popularity despite its minimal donor site morbidity. In our small series of cases among previously burned skin, we presented one case when the use of this flap was not feasible from a variable or altered anatomy. This was found after the flap was raised and
the distal PIA (relative to the flap and not the extremity) has already been ligated. The flap was eventually discarded and a salvage groin flap performed. In retrospect, knowing that the anatomy at the level of the anastomosis to the AIA can be variable, complete vessel dissection prior to ligation of the distal pedicle may be prudent. Nevertheless, despite loss of the flap substance, the patient did not sustain any long term functional deficit or incur additional scars. Central to the avoidance of using previously burned skin is perhaps rooted in the conventional wisdom that thermal energy has altered the microcirculation and therefore, increases the risk of flap failure [6]. Indeed, burn scars and skin grafts do demonstrate marked early changes in its vascularity [6] as demonstrated on a macro-scale as hyperemia. Histologically, large, tortuous vessels are observed with minimal interconnections. These changes persist months to years after injury. The minimal collateralization is consistent with our experience that flaps using previously burned skin may be more prone to venous congestion. While the venous congestion is generally not long lasting, conventional modalities for treatment venous congestion should be considered including elevation, relieving a tight inset, the use of mechanical, chemical or biologic leeching, temporarily putting the flap back in its original position and intermittent drainage using a venous catheter [17]. Furthermore, to decrease the incidence of venous congestion, consideration should always be given to preserving a skin
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Fig. 3 – (Case 2) Bilateral exposed dorsal ulnar styloids (A, right and left). Preoperative markings indicate the proposed location of the skin paddle, situated over the proposed PIA (B). Intra-operative dissection of the fasciocutaneous flap with the underlying PIA observed (C). The flap has been inset and seen intra-operatively (D, right and left). Long term postoperative follow up demonstrates again essentially no additional scars (E, right and left).
bridge to maximize venous efflux instead of a true island flap [15]. Other critics of this flap argue that the loss of a major axial vessel supplying an already compromised extremity may result in additional disability. Some prefer use of a groin flap, a
workhorse for difficult wounds of the dorsal hand and wrist. However, because of its positioning requirements, it is not our first choice of reconstruction as it interferes with wound care and rehabilitation of a recently burned patient. Microvascular free tissue transfer should also be considered but in the
burns 42 (2016) e24–e30
5.
e29
Conclusions
Defects of the distal ulnar wrist after extensive burns can be problematic. The reverse posterior interosseous flap, using previously burned or recently grafted skin should be in the armamentarium of the reconstructive surgeon. Meticulous dissection, inclusion of the fascia, preservation of the intramuscular septal perforators and flap design to minimize venous congestion are essential for its success.
Conflict of interest statement The authors have no disclosures or conflicts of interest.
Funding None.
references
Fig. 4 – (Case 3) Unsuccessful coverage of exposed ulnar styloid. Unilateral exposed dorsal ulnar styloid is observed (A). Preoperative markings indicate the proposed location of the PIA and skin paddle (B). PIA identified but no retrograde flow was present after division of the distal vessel (C). The patient ultimately underwent a pedicled abdominal flap for coverage.
hyperdynamic, hyperinflammed patient with a large percentage TBSA, is also not our first choice for reconstruction. Furthermore, unlike the sacrifice of the radial artery in the case of a radial forearm flap, sacrifice of the PIA, an axial end vessel not critical for distal perfusion, likely results in minimal morbidity. In our patients, although these aforementioned reconstructive options were possible, the rPIF flap was chosen as it provided the least morbidity while still providing durable coverage. We have shown the reverse PIF, using previously burned and recently grafted skin is a good option for the coverage of defects of the dorsal distal ulnar wrist. While there is a slight learning curve and possible anatomic variation of its vascular anatomy, it is a non-axial vessel of the forearm and results in minimal to no functional morbidity. Furthermore, the flap donor site is virtually inperceptible.
[1] Fletcher JL, Caterson EJ, Hale RG, Cancio LC, Renz EM, Chan RK. Characterization of skin allograft use in thermal injury. J Burn Care Res 2013;34(1):168–75. [2] Jones NF, Jarrahy R, Kaufman MR. Radial forearm flaps for reconstruction of the elbow, wrist, and hand. Plast Reconstr Surg 2008;121:887–9. [3] El-Shazly M. Fashioning reversed axial pattern forearm tissues in different challenging conditions of the forearm territory as a reliable substitute for free tissue transfer. Acta Chir Plast 2012;54(2):53–8. [4] Hekner DD. Donor-site morbidity of the radial forearm free flap versus the ulnar forearm free flap. Plast Reconstr Surg 2013;132:387–93. [5] Saleh Y, El-Shazly M, Adly S, El-Oteify M. Different surgical reconstruction modalities of the post-burn mutilated hand based on a prospective review of a cohort of patients. Ann Burns Fire Disasters 2008;21(June (2)):81–9. [6] Barret J, Herndon D, McCauley R. Use of previously burned skin as random cutaneous local flaps in pediatric burn reconstruction. Burns 2002;28(5):500–2. [7] Page RE, Robertson GA, Pettigrew NM. Microcirculation in hypertrophic burn scars. Burns Incl Therm Inj 1983;10(1): 64–70. [8] Cheema TA, Lakshman S, Cheema MA, Durrani SF. Reverse-flow posterior interosseous flap-a review of 68 cases. Hand (N Y) 2007;2(3):112–6. [9] Mathes S, Nahai F, editors. Reconstructive surgery: principles, anatomy & technique. New York: Churchill Livingstone; 1997. [10] Kai S, Zhao J, Jin Z, Wu W, Yang M, Wang Y, et al. Release of severe post-burn contracture of the first web space using the reverse posterior interosseous flap: our experience with 12 cases. Burns 2013;39(6):1285–9. [11] Zancolli EA, Angrigiani C. Posterior interosseous island forearm flap. J Hand Surg Br 1988;13(2):130–5. [12] Strauch B, Yu HL. Posterior interosseous flap (posterior forearm flap). In: Atlas of microvascular surgery: anatomy and operative approaches. New York, NY: Thieme Medical Publishers, Inc.; 2006: 77. [13] Pribaz JJ, Pelham FR. Use of previously burned skin in local fasciocutaneous flaps for upper extremity reconstruction. Ann Plast Surg 1994;33(3):272–80.
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[14] Hallock GG. The role of local fasciocutaneous flaps in total burn wound management. Plast Reconstr Surg 1992;90(4):629–35. [15] Chan R, Pribaz J. Use of previously burnt skin in local fasciocutaneous flaps. In color atlas of burn reconstructive surgery. Heidelberg: Springer; 2010. [16] Rozen WM, Hong MK, Ashton MW, Ferris S. Imaging the posterior interosseous artery with computed tomographic
angiography: report of a rare anomaly and implications for hand reconstruction. Ann Plast Surg 2010;65(3): 300–1. [17] Chan RK, Liu A, Bojovic B, Chun Y, Guo L, Caterson SA, et al. Venous congestion in abdominal flap breast reconstructions – a simple treatment for a temporary problem. J Plast Reconstr Aesthet Surg 2011;64(5): e135–6.
Available online at www.sciencedirect.com
ScienceDirect journal homepage: www.elsevier.com/locate/burns
Case report
Reverse posterior interosseous flap for defects of the dorsal ulnar wrist using previously burned and recently grafted skin Joseph M. Baylan a, J. Alan Chambers c, Neil McMullin b, John L. Fletcher b, Indranil Sinha d, Jonathan Lundy b, Booker T. King b, Rodney K. Chan b,* a
Department of Surgery, Scott and White Hospital Systems, Temple, TX, United States Clinical Division and Burn Center, US Army Institute of Surgical Research, 3650 Chambers Pass, Fort Sam Houston, TX, United States c Walter Reed National Military Medical Center, Washington, DC, United States d Division of Plastic Surgery, Brigham and Women’s Hospital, Boston, MA, United States b
article info
abstract
Article history:
Background: In the severely burned patient, coverage of exposed bone in the dorsal ulnar
Accepted 29 June 2015
wrist can be a difficult problem. This is especially challenging in patients with a high
Keywords:
previously burned and/or recently grafted skin as flaps is an option. It has been postulated
Hand burn
that use of previously burned skin can result in higher rates of local or distant flap failures.
percentage total body surface area (TBSA) where donor flaps can be scarce. The use of
Posterior interosseous artery flap
The reverse posterior interosseous flap (PIF) is an axial flap, based on the retrograde posterior interosseous artery, to provide coverage of the hand. Here we describe utilization of the PIF, using previously burned and/or recently grafted skin for coverage of dorsal ulnar wrist defects. Methods: This is a case series of three patients, with extensive burns (range 35–83%TBSA), where defects of the dorsal ulnar wrist necessitated coverage. Each patient underwent PIF(s) utilizing previously burned and/or grafted skin, all within three months after their initial burn event. Results: Case 1: 28 year old male who suffered 35% TBSA via blast mechanism developed a chronic open wound over the dorsal ulnar wrist with exposed tendon. The patient successfully underwent a left PIF using previously grafted skin. Case 2: 23 year old male with 83% TBSA. Bilateral ulnar styloids were exposed. PIFs were performed bilaterally, using previously burned and recently grafted skin. Coverage was successful but received leech therapy post-operatively for venous congestion. Case 3: 37 year old male with 52% TBSA, with the most severe burns isolated to his bilateral upper extremities; the ulnar head was exposed. The posterior interroseous artery was explored and PIF was attempted, but there was no retrograde flow in the distal artery due to a deeper injury than previously recognized. The patient ultimately underwent a pedicled abdominal flap for coverage.
* Corresponding author at: Clinical Division and Burn Center, U.S. Army Institute of Surgical Research, 3650 Chambers Pass, Fort Sam Houston, TX 78234-6315, United States. Tel.: +1 210 539 8511; fax: +1 210 916 9148. E-mail address: [email protected] (R.K. Chan). http://dx.doi.org/10.1016/j.burns.2015.06.020 0305-4179/# 2015 Elsevier Ltd and ISBI. All rights reserved.
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burns 42 (2016) e24–e30
Conclusions: Defects of the distal ulnar wrist after deep and extensive burns can be problematic. Use of the reverse PIF using previously burned skin, even those that has just been recently grafted is a viable option for this difficult patient population. However, it may not be possible in all patients. Vigilance and early intervention for post-operative venous congestion are important. # 2015 Elsevier Ltd and ISBI. All rights reserved.
1.
Introduction
Soft tissue coverage of upper extremity defects is challenging, especially when bone, tendons or joints are exposed. The upper extremities are the most common areas of burn involvement [1]. The dorsal ulnar at the level of the wrist is particularly prone to exposure as the amount of native soft tissue coverage is thin. This problem is compounded in burn patients where limited donor options and contiguous areas of burn involvement often exist. Options for flap coverage of wounds in this area includes radial forearm or ulnar artery pedicled flaps [2,3]. Both however may have significant donor site morbidity [4]. Additionally, pedicled groin or abdominal flaps offer a reliable option for reconstruction, but require multiple operations and can result in significant hand stiffness [5]. The reversed posterior interosseous artery flap (rPIF) represents a viable option as well. In addition, the use of previously burned and recently grafted skin as flaps has been reported in the literature but its use has been limited [6]. Several authors have postulated that use of burned skin can result in higher rates of local or distant flap failures due to altered microcirculation within the subcutaneous tissue [7]. The (rPIF) is a fasciocutaneous flap, based on retrograde flow into the posterior interosseous artery from its distal anastomosis to the anterior interosseous artery [8]. The rPIF allows coverage of the dorsal wrist, thumb, hand, and first webspace [9]. First described as a reverse flow pedicled flap in 1986 [10,11], the advantages of the rPIF include proximity to the hand, minimal injury to the main lymphatics and vessels of the forearm and the potential to primarily close the donor; depending on skin paddle size [6]. Disadvantages include variable perforator anatomy and possible disruption of the anterior interosseous artery anastomosis. Here we describe our experience using previously burned skin in reverse posterior interosseous flaps for coverage of dorsal ulnar wrist defects.
which exists as a branch of the common interosseous artery (CIA) and most often possesses a distal anastomosis with the anterior interosseous artery (AIA). Surgically the PIA is encountered proximally as it emerges from under the supinator muscle and descends on the proximal muscle bellies of abductor pollicus longus (APL) and extensor pollicis longus (EPL) muscles (Fig. 1). The PIA to AIA anastomotic branch dives deep to the extensor indicis muscle penetrating the interosseous membrane. Most commonly the PIA supports three branches supplying the supinator, APL and EPL muscles. Strauch and Yu report absence of the AIA to PIA anastomotic branch (2–3%) or a robust retrograde PIA without a large recurrent AIA branch (5.7%) [12]. The consequences of these variations are obvious and preclude the use of the rPIF. Typically the posterior interosseous nerve (PIN) lies deep and lateral to the PIA with the extensor carpi ulnaris (ECU) motor branch crossing deep to the PIA. There are, however described variants where the ECU motor branch of the PIN crosses superficial to the PIA.
2.2.
Surgical technique
A review of the senior author’s personal records identified three patients, with thermal injury mechanism (range 35– 83%TBSA), who underwent four rPIF procedures for soft-tissue defects exposing the dorsal ulnar styloid. Each patient underwent rPIF utilizing previously burned and grafted skin, all within three months after their initial burn event and 6–10 weeks following attempted grafting.
A line is drawn from the lateral epicondyle to the distal radioulnar joint while the arm is in resting elbow flexion, corresponding to the axis of the PIA. Construction of the skin paddle is completed along this axis and is based from the middle third of the forearm so as to include sufficient pedicle length for rotation. This flap may be designed as an island pedicle flap or with the inclusion of a skin bridge. Preoperative doppler ultrasound aids in detection of perforators. The flap is raised from the ulnar border incorporating the deep fascia in the flap. Caution is warranted as the surgeon’s dissection reaches the radial border of the extensor carpi ulnaris (ECU) to include the fascial attachments from the pedicle to the fascia. Once the pedicle is identified, the radial incision is made and the muscle belly of the extensor digiti minimi (EDM) identified. EDM is then retracted radially, the ECU ulnarly and attention is turned to identifying and preserving the PIN to include its ECU motor branch proximally. The PIA is dissected, taking care capture all perforators feeding the skin paddle. The proximal PIA and venae comitantes may be ligated and divided early to facilitate flap dissection. Once sufficient pedicle length is achieved, the flap is rotated into place, and the resulting donor defect is covered with splitthickness skin graft. Splint to keep the wrist in slight extension is advisable but it is important to avoid pressure on the pedicle.
2.1.
2.3.
2.
Methods
Relevant anatomy
As has been previously described [8] the rPIF is based on retrograde flow within the posterior interosseous artery (PIA)
Flap monitoring
Once inset, the flap can be monitored similarly to any pedicled flap. Congestion or insufficiency will manifest with
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Fig. 1 – Cross-sectional view of the wrist. Red contour indicates the location of PIA flap, which includes the fascia overlying the ECU and ED. Location of the interroseous membrane (IM) and the Anterior Interroseous Artery (AIA) are noted.
changes to the flap color and turgor, even in the presence of burned skin. A change in the appearance of the flap could signify vascular compromise and warrants exploration of the vascular pedicle.
3.
Results
3.1.
Case 1
28 year old male with 35% TBSA degree burns to face, bilateral upper extremities, back, buttocks, and posterior lower extremities via blast mechanism. Multiple operations to the dorsal ulnar wrist including a local flap failed. A chronic open wound developed over the dorsal ulnar wrist with exposed FCU tendon. The patient underwent a left reverse PIF using previously burned and grafted skin. Skin graft was applied to flap donor site. Post-operative stay was uneventful and flap was successful (Fig. 2).
3.2.
Case 2
23 year old male with 83% TBSA to face, trunk, upper and lower extremities secondary to flame burn with exposed ulnar styloids bilaterally. During his initial hospitalization, bilateral reverse PIFs were performed to provide coverage to his dorsal ulnar wrist defects using previously burned and recently grafted skin. Donor sites were grafted. Leech therapy was prescribed post-operatively for venous congestion but flap coverage was ultimately viable and successful (Fig. 3).
3.3.
Case 3
37 year old male with 52% TBSA to trunk, upper extremities, face, and thighs via flame burn. Multiple debridements and grafting procedures including reverse radial forearm flap to cover exposed wrist tendons on the left. However, a distal ulnar wrist remained with exposed bone. Left reverse PIF was attempted. Intraoperatively, the course of the PIA was identified by Doppler ultrasound, though the signal was admittedly faint. We proceeded with flap dissection and division of the distal pedicle. At that point, it became evident that there was no communication with the anterior interosseous artery. The patient ultimately underwent successful pedicled abdominal flap for coverage (Fig. 4).
4.
Discussion
Defects of the dorsal ulnar wrist present a challenging yet common problem in upper extremity burns. Use of previously burned and recently grafted skin as flaps when the deep fascia is intact is an attractive option with minimal donor site morbidity. We have described the use of a reverse posterior interroseous artery flap in previously burned and recently grafted skin for exposed ulnar styloid. The use of previously burned skin as flaps is not a novel concept. Most burn contracture releases using Z-plasties or transfer of adjacent tissue successfully incorporate some component of previously burned or grafted skin and represent the workhorse of burn reconstructive surgery [2]. However, the use of previously burned skin as island or pedicle flaps has not
burns 42 (2016) e24–e30
e27
Fig. 2 – (Case 1) Unilateral exposed dorsal ulnar styloid is observed. Preoperative markings indicate the proposed location of the PIA and ECU and EDM muscle bellies (A). A skin bridge is left in place to prevent venous congestion. The flap has been inset and seen intra-operatively (B). The donor site has been covered with a split thickness skin graft, and there is no evidence of venous congestion (C). Long term post-operative follow up with minimal morbidity and essentially no additional scars (D).
been met with similar level of enthusiasm. Pribaz and Pelham published the first large series using previously burned skin in 40 fasciocutaneous flaps. Among them, six posterior interosseous flaps were reported though most were performed in the non-acute period to resurface contractures of the first webspace [13]. In their discussion, Pribaz and Pelham emphasized the importance of fully harvesting the fascia along with the desired soft-tissues to provide the most durable vascular supply to the rotated tissues [13]. Hallock et al. describes initial flaps using burned skin were raised with failure to recognize importance of deep fascia in protecting circulation to the integument [14]. Fasciocutaneous flaps are specifically relevant to the use of previously burned skin since perforators to the deep fascia usually are found deep in the intermuscular septa and are protected even in deep burns [14]. It is imperative to raise the previously burned or skin grafted flap with its underlying fascia in order to capture its blood supply [15]. The rPIF was first described by in 1986 and can be utilized as a composite carrying muscle, tendon, or ulnar bone if indicated [10]. Based on the retrograde PIA, it is an option to cover defects of the wrist and hand. Because of its variable vascular anatomy [16], however, it has not gained popularity despite its minimal donor site morbidity. In our small series of cases among previously burned skin, we presented one case when the use of this flap was not feasible from a variable or altered anatomy. This was found after the flap was raised and
the distal PIA (relative to the flap and not the extremity) has already been ligated. The flap was eventually discarded and a salvage groin flap performed. In retrospect, knowing that the anatomy at the level of the anastomosis to the AIA can be variable, complete vessel dissection prior to ligation of the distal pedicle may be prudent. Nevertheless, despite loss of the flap substance, the patient did not sustain any long term functional deficit or incur additional scars. Central to the avoidance of using previously burned skin is perhaps rooted in the conventional wisdom that thermal energy has altered the microcirculation and therefore, increases the risk of flap failure [6]. Indeed, burn scars and skin grafts do demonstrate marked early changes in its vascularity [6] as demonstrated on a macro-scale as hyperemia. Histologically, large, tortuous vessels are observed with minimal interconnections. These changes persist months to years after injury. The minimal collateralization is consistent with our experience that flaps using previously burned skin may be more prone to venous congestion. While the venous congestion is generally not long lasting, conventional modalities for treatment venous congestion should be considered including elevation, relieving a tight inset, the use of mechanical, chemical or biologic leeching, temporarily putting the flap back in its original position and intermittent drainage using a venous catheter [17]. Furthermore, to decrease the incidence of venous congestion, consideration should always be given to preserving a skin
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Fig. 3 – (Case 2) Bilateral exposed dorsal ulnar styloids (A, right and left). Preoperative markings indicate the proposed location of the skin paddle, situated over the proposed PIA (B). Intra-operative dissection of the fasciocutaneous flap with the underlying PIA observed (C). The flap has been inset and seen intra-operatively (D, right and left). Long term postoperative follow up demonstrates again essentially no additional scars (E, right and left).
bridge to maximize venous efflux instead of a true island flap [15]. Other critics of this flap argue that the loss of a major axial vessel supplying an already compromised extremity may result in additional disability. Some prefer use of a groin flap, a
workhorse for difficult wounds of the dorsal hand and wrist. However, because of its positioning requirements, it is not our first choice of reconstruction as it interferes with wound care and rehabilitation of a recently burned patient. Microvascular free tissue transfer should also be considered but in the
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Conclusions
Defects of the distal ulnar wrist after extensive burns can be problematic. The reverse posterior interosseous flap, using previously burned or recently grafted skin should be in the armamentarium of the reconstructive surgeon. Meticulous dissection, inclusion of the fascia, preservation of the intramuscular septal perforators and flap design to minimize venous congestion are essential for its success.
Conflict of interest statement The authors have no disclosures or conflicts of interest.
Funding None.
references
Fig. 4 – (Case 3) Unsuccessful coverage of exposed ulnar styloid. Unilateral exposed dorsal ulnar styloid is observed (A). Preoperative markings indicate the proposed location of the PIA and skin paddle (B). PIA identified but no retrograde flow was present after division of the distal vessel (C). The patient ultimately underwent a pedicled abdominal flap for coverage.
hyperdynamic, hyperinflammed patient with a large percentage TBSA, is also not our first choice for reconstruction. Furthermore, unlike the sacrifice of the radial artery in the case of a radial forearm flap, sacrifice of the PIA, an axial end vessel not critical for distal perfusion, likely results in minimal morbidity. In our patients, although these aforementioned reconstructive options were possible, the rPIF flap was chosen as it provided the least morbidity while still providing durable coverage. We have shown the reverse PIF, using previously burned and recently grafted skin is a good option for the coverage of defects of the dorsal distal ulnar wrist. While there is a slight learning curve and possible anatomic variation of its vascular anatomy, it is a non-axial vessel of the forearm and results in minimal to no functional morbidity. Furthermore, the flap donor site is virtually inperceptible.
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