Role of Reversed Sural Artery Flap in Reconstruction of Lower Third of the Leg, Ankle and Foot Defects

Introduction: Coverage of defects of the distal lower extremity and foot remains a challenging reconstructive procedure. Free tissue transfer remains the standard for the management of these defects. However, there are some disadvantages like; longer operative times, bulky contour, and the need for highly skilled expertise. The reverse superficial sural artery flap (RSSAF) is a distally based fasciocutaneous or adipo-fascial flap that is used for coverage of defects that involve the distal third of the leg, ankle, and foot. A significant advantage of this flap is a constant blood supply that does not require sacrifice of a major artery. Methods: Twenty RSSAF flaps were harvested for reconstruction of different traumatic soft tissue defects of the lower third of leg, ankle and foot. Follow up for 6 months postoperative. Results: Twenty Patients; twelve males and eight females underwent reconstruction of different soft tissue defects over the foot and ankle using RSSAF. The overall complications occurred in 6 flaps; 4 minor and 2 major complications. The remaining 14 flaps passed an uneventful follow up. Conclusions: The reverse superficial sural artery flap RSSAF can be used as a reliable alternative to free tissue transfer in reconstruction of defects over the lower third of leg, ankle, and foot. Venous congestion is the major threat to the flap but its incidence can be minimized by wide pedicle, less kink of the flap, and keep the venae comitants around the artery.

challenging reconstructive procedure. Unreliable blood supply and paucity of local donor tissue often preclude the use of local and regional flaps [1].
Free tissue transfer remains the standard for the management of these complicated wounds. However, even with its many advantages, it is encumbered by donor site morbidity, longer operative times, bulky contours, recipient vessel trauma, and the requirement for advanced surgical expertise and expensive equipment. Moreover, not every patient is a good candidate for prolonged general anesthesia. These issues highlight the need for locally based tissue reconstructive alternatives that are shorter in duration, easy to perform, and reliable.
The RSSAF has been touted to be the ideal solution [2] [3].
The reverse superficial sural artery flap (RSSAF) is a distally based fasciocutaneous or adipo-fascial flap that is used for coverage of defects that involve the distal third of the leg, ankle, and foot. Donski  has become a popular option for many of these difficult wounds [4] [5].
A significant advantage of this flap is a constant blood supply that does not require sacrifice or manipulation of a major artery to the lower limb. These flaps are vascularized by septo-cutaneous perforators of the peroneal artery that anastomose with the peri-neural and peri-venous arterial networks of the sural nerve and the lesser saphenous vein, respectively [6].
However, the RSSAF is often at risk for venous congestion, as it relies on communication between the venae comitants of the sural nerve and the lesser saphenous vein, thus hinders the valves of the deep venous system [7]. This impaired venous drainage of the RSSAF may contribute to flap necrosis in the early postoperative period [7].
It has shown that flap survival was improved by various modifications to the operative technique that enhanced venous outflow of the RSSAF, and that these changes reduced the use of leech therapy [8].
Several revisions to the operative technique have been proposed since its original description almost 35 years ago [9] and the RSSAF is now considered an accepted and popular method for coverage of soft-tissue loss in the distal third of the leg, ankle, and foot from a number of etiologies [10].
Compared with other local and regional flaps, the RSSAF has a larger arc of rotation than the extensor digitorum brevis and peroneus brevis muscle flaps.
[11] [12] Long periods of immobilization and difficult positioning are avoided unlike the cross-leg flap [13]. Also, the RSSAF has been shown to be significantly more reliable than the lateral supra-malleolar flap [14].

Surgical Technique
The patient was placed in supine position. Debridement of the defect was done.
The patient was placed in the prone position. Perforating vessels from the pero- Complications were analyzed, a major complication was defined as necrosis and loss of any part of the flap that needed further interference (debridement and grafting), while mild venous congestion, epidermolysis leading to impairment of wound healing that could be treated conservatively was defined as a minor complication.

Results
Patient data are summarized in Table 1.

Discussion
The distal lower extremity and foot have long been recognized as problematic areas for reconstruction because local donor tissue is often insufficient or is located within the zone of injury. Also, unreliable blood supply plays a role in difficulty of reconstruction using local and regional flaps. Goals of reconstruction are to provide stable soft-tissue coverage [2].
Microsurgical reconstruction remains the standard for the management of these complicated wounds. Even with its many advantages, there are multiple drawbacks longer operative times, potential donor site morbidity, special expensive instruments and the requisite for qualified surgeons with microsurgical experience. Moreover, not every patient is a good candidate for prolonged general anesthesia. These drawbacks pushes the surgeons towards finding alternatives that are reliable and can compete for these drawbacks [15].
During our study, The RSSA flap was used as the choice for reconstruction of defects of the lower third of the leg, ankle and foot. We harvested the flaps with length ranged from 10 cm up to 20 cm with a mean length of 15 cm, while the width ranged from 5 cm up to 10 cm with a mean width of 7.5 cm. Some of the flaps were used to cover more than one area.
Out of the 20 flaps, 70% showed no complications, 20% showed epidermolysis due to mild venous congestion, and only 10% showed partial necrosis.  very high between patients treated with RSSAF. During their study, venous congestion occurred in 75% and 67% in both groups respectively [19].
From all the previous results and other similar studies, we found that RSSAF can be harvested to cover defects over the lower third of the leg, ankle and foot.
The flap is easy to harvest, can cover large areas, with good reliability, and low rate of complications. The flap can be used as a good reliable alternative for free tissue transfer in reconstruction of the difficult defects over the lower third of the leg, ankle, and foot.

Conclusion
The reverse superficial sural artery flap RSSAF can be used as a reliable alternative to free tissue transfer in reconstruction of defects over the lower third of leg, ankle, and foot. Venous congestion is the major threat to the flap but its incidence can be minimized by wide pedicle, less kink of the flap, involvement of the lesser saphenous vein in the flap and keep the venae comitants around the artery.