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Versatility of the sural fasciocutaneous flap in the coverage of lower third leg and hind foot defects
Journal of Plastic, Reconstructive & Aesthetic Surgery (2006) 59, 839–845
Versatility of the sural fasciocutaneous flap in the coverage of lower third leg and hind foot defects Shaheen Akhtar*, A. Hameed Department of Plastic and Reconstructive Surgery, Shaikh Zayed Postgraduate Medical Institute, Lahore, Pakistan Received 20 November 2005; accepted 28 December 2005
KEYWORDS Sural; Fasciocutaneous; Marjolin; Tendo-achillis
Summary Background: Reconstruction of soft tissue defects of the lower third of the leg, the heel and the hind foot remains a challenge. The distally based sural artery fasciocutaneous flap has been used effectively to resurface these defects. In many instances, it has obviated the need for free tissue transfer. Objective: The objective of the study is to evaluate the efficacy of reverse sural artery fasciocutaneous flap for coverage of lower third leg, posterior heel, malleoli and hind foot. Study design: This is a descriptive study, which was conducted on 84 patients who presented with soft tissue defects in the area of lower third leg, heel, malleoli and hind foot. Place and duration of study: The study was conducted at department of plastic and reconstructive surgery, Federal Postgraduate Medical Institute Shaikh Zayed Hospital Lahore, over a period of 7 years from February 1997 to February 2005. Patients and methods: Over a period of 7 years, a total of 84 patients with Soft tissue defect of lower third leg, heel, malleoli and hind foot were included. Preoperative data, the age and sex of each patient, cause and site of defect, dimension of flap, transposition of pedicle (through a tunnel or laid open and covered with a skin graft), postoperative results and complications were recorded. All patients were followed up in out patients department for 6 months. Results: Out of 84 patients, 54 were males and 30 females. Their ages ranged from 8 to 55 years with a mean of 31 years. Road traffic accidents was the cause of the defects in 53 patients, wheel spoke injury in 12 patients, trophic ulcer in five patients, osteomyelitis in five patients, marjolin ulcer in seven patients and diabetic ulcer in two patients. The site of 84 defects comprised 52 distal tibia; 20 tendoAchillis and posterior heel defects; seven-malleolar region; three-anterior ankle and two-foot amputation stumps. The dimension of flap ranged from 5 to 15 cm in length and 4 to 12 cm in width. Postoperatively 66 flaps survived completely while marginal necrosis was seen in six patients and infection in four patients. The complete flap necrosis occurred in eight
* Corresponding author. Address: Shaikh Zayed Hospital, Room No 12, 2nd Floor Lady Doctor’s Hostel, Lahore, Pakistan. Tel.: C92 300 4317423. E-mail addresses: [email protected] (S. Akhtar), [email protected] (A. Hameed).
S0007-1226/$ - see front matter q 2006 The British Association of Plastic Surgeons. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.bjps.2005.12.009
840
S. Akhtar, A. Hameed patients. There was no considerable morbidity at donor site and all patients had satisfactory functional outcome. Conclusions: The distally based superficial sural artery flap is a versatile, reliable procedure, useful in reconstruction of lower third leg, heel, malleoli and hind foot defects. The surgical technique is safe, of short duration and provides alternative to microsurgical reconstruction. q 2006 The British Association of Plastic Surgeons. Published by Elsevier Ltd. All rights reserved.
The reconstruction of soft tissue defects of lower third of the leg, Achilles tendon, malleoli, ankle, and calcaneal area presents a challenging problem for reconstructive surgeon because of paucity of local cutaneous, fasciocutaneous and muscle flaps in this area. Trauma and other deforming processes can involve soft tissue, underlying bone, ligamentous structures and defects that expose the tendon and bone directly. The heel is a weight bearing area, and this area is traumatized frequently. In addition, the skin over these areas is tight and has poor circulation. There are many possible reconstructive options, including skin grafts, local flaps, distant flaps and free flaps but their usage is limited and problems exist in these regions. Skin grafts are not suitable to cover the exposed bone, tendon, malleoli, heel, and weight bearing areas. Absence of peripheral pulses, diabetes, and peripheral vascular thromboses are contraindications to local flaps. Free tissue transfers provide excellent tissue coverage but require a microvascular team and equipment. In addition free tissue transfers are lengthy procedures. A better knowledge of the cutaneous blood supply from the neurovascular axis has allowed the creation and usage of distally based neurocutaneous flap of sural nerve. The concept of ‘neuroskin island flap’, developed by Masquelet et al., is well accepted.1 Such flaps are based on the cutaneous branches of the vascular axis around a superficial sensory nerve. The distally based sural fasciocutaneous flap, perfused by the lower peroneal septocutaneous perforators is based on this concept. It has been described for the reconstruction of soft tissue defects of lower leg, foot and ankle by many authors, who studied and exploited its usefulness.2–5
Surgical anatomy The superficial sural artery arises from the popliteal artery. The artery courses posteriorly for 2–3 cm before joining the sural nerve, descending between the two heads of the gastrocnemius muscle; it
follows the lateral edge of Achilles tendon. The artery courses along the sural nerve and intimately connected to it has an important role in the blood supply of the skin flap in the lower and middle third leg.3,6 It is either terminates or anastomoses with the supramalleolar branch of peroneal artery and posterior tibial artery. The artery gives off many arteria nervosum to the sural nerve with septocutaneous perforators. Usually paired venae comitantes travel with the superficial sural artery. Approximately four to eight fasciocutaneous perforators arising from the peroneal artery and venae comitantes follow the course of the crural fascia, they give rise to several branches that communicate with adjacent perforators, forming an interconnecting vascular plexus on crural fascia. The plexus extends from the posterior margin of the lateral malleolus to the superior part of the leg. Multiple communications exist between this fascial network and superficial sural artery and the overlying subcutaneous and subdermal plexus. The connection between the septocutaneous vessels form a rich suprafascial plexus with longitudinally oriented arcades. Larger perforator is often located approximately 5 cm superior to the lateral malleolus. The sural nerve descends in close association with the lesser saphenous vein, passing posterior to the lateral malleolous to supply the lateral side of the foot and fifth toe. This nerve is supplied by the superficial sural artery in the proximal one-third of leg. The distal two-thirds of the nerve is supplied by the fasciocutaneous branches of the peroneal artery. These branches course along the upper surface of the crural fascia for a variable distance before supplying the nerve; consequently, a longitudinal strip of fascia must be harvested with the nerve. In addition, the sural nerve has also intrinsic blood supply. The intrinsic system consists of epineural, perineural and endoneural vessels, longitudinally oriented with multiple levels of communication. This system has a connection with the superficial sural artery and fasciocutaneous branches of the peroneal artery.1,7
Versatility of the sural fasciocutaneous flap in the coverage of lower third leg and hind foot defects
841
The lesser saphenous vein takes its origin from the lateral extension of the dorsal venous arch of foot. It passes posteriorly to the lateral malleolus accompanied by the sural nerve. AT the junction of the distal and middle third of the leg, the lesser saphenous vein is located more medially and follows the course of the sural nerve.
Surgical techniques The flap is approached with the patient in prone position. The pneumatic tourniquet is used during flap elevation. Debridement of recipient area is done (Fig. 1) Marking is done with a line drawn from a point midway between the Achilles tendon and the lateral malleolus to the midline between two heads of the gastrocnemius muscle (Fig. 2). This roughly delimeates the course of sural nerve. After that attention is focused to mark the larger peroneal perforator, which is often located approximately 5 cm superior to the tip of the lateral malleolus. The template of the defect of recipient area is made. The flap is then outlined and centred over the sural nerve. This flap can be located anywhere in the lower two-thirds of the posterior aspect of the leg according to the need of pedicle length. An incision is made along the superior border of the flap (Fig. 3). At mid calf, the sural nerve and lesser saphenous vein are identified suprafascially (Fig. 4). The sural nerve, artery and lesser saphenous vein are divided and ligated, and included within the flap. The dissection is then continued around the distal aspect of the flap in the subfascial plane. Musculocutaneous perforators from the underlying gastrocnemius muscle are identified and coagulated. Distally a longitudinal strip of the fascia and subcutaneous fascial pedicle,
Figure 1
Soft tissue defect on medial malleolus.
Figure 2
Marking of flap.
which includes the sural nerve and lesser saphenous vein, is elevated with a width of 2–3 cm to protect the neurovascular axis. The lateral extent of dissection is up to fibula and on medial extent is the lateral border of Achilles tendon. The dissection is stopped 5 cm above the lateral malleolus where perforators from the peroneal artery communicate with the vascular plexus. The pivot point of the flap is also 5 cm above the tip of lateral malleolus. The flap is now transposed through a subcutaneous tunnel to the recipient area over a corrugated drain (Figs. 5 and 6). If there is any risk of compression of the pedicle, division of the skin bridge between the donor site and the defect is done. In these cases, pedicle is usually covered with a split thickness skin graft. The donor site is then covered with a split thickness skin graft (Fig. 7). A full-leg posterior splint with wellpadded dressing is applied making sure that there is no compression on the pedicle. The flap is left exposed for observation. The dressing is changed on 5th postoperative day. The flap usually heals by 3rd
Figure 3
Start of dissection.
842
S. Akhtar, A. Hameed
Figure 4
Figure 6
Dissected pedicle.
week but full weight bearing on flaps used for heel defects is postponed up to 6th week.
Patients and methods This study was conducted at department of plastic and reconstructive surgery, Federal Postgraduate Medical Institute Shaikh Zayed Hospital Lahore, over a period of 7 years during February 1997 to February 2005. It included 84 patients with Soft tissue defects of lower third leg, around the heel and ankle and hind foot. The age and sex of each patient, cause and site of defect, dimension of flap, transposition of pedicle (through a tunnel or laid open and covered with a skin graft), postoperative results and complications were recorded. There were six patients who had diabetes mellitus of short duration, which was controlled preoperatively with a sliding scale of insulin. X-rays of the recipient site were done in all cases to evaluate the condition of
Figure 5 Flap transposed to recipient site (medial malleolus).
Flap with the drain.
the underlying bone and to rule out osteomyelitis. The external fixator in post-traumatic patients was readjusted, if required. All patients were followed up in out patients department for 6 months. The setting of the flap and functional out come was recorded.
Results Over a period of 7 years during February 1997 to February 2005, a total of 84 flaps were performed in 84 patients. Fifty-four patients were male and 30 were female. Their ages ranged from 8 to 55 years with a mean age of 31 years (Fig. 8). There were seven children. Road traffic accidents was the cause of the defects in 53 (63%) patients, wheel spoke injury in 12 (14%) patients, trophic ulcer in five (6%) patients, osteomyelitis in five (6%) patients, Marjolin ulcer in seven (8.5%) patients and diabetic ulcer in two (2.5%) patients (Fig. 9). The site of 84 defects comprised 52 (62%) distal tibia; 20 (24%) tendo-
Figure 7
Donor site and pedicle covered with graft.
Versatility of the sural fasciocutaneous flap in the coverage of lower third leg and hind foot defects
Figure 8
Age distribution.
Figure 11
Figure 9
Etiology.
achillis and posterior heel defects; seven (8.5%) malleolar region; three (3.5%) anterior ankle and two (2.5%) foot amputation stumps (Fig. 10). In all cases, defects were covered with reverse sural island flap with an addition of skin graft in 15 patients. The dimension of the flap ranged from 5 to 15 cm in length and from 4 to 12 in width. The mean length was 10 cm and width measured 8 cm. The largest flaps were transposed to posterior heel defects and foot amputation stumps. All flaps were island flaps. Forty-eight flaps were transposed to the recipient site through a tunnel, while pedicle of 36 flaps was laid open and covered with split thickness skin graft. Out of 84 flaps; 66 (78.5%) showed the complete healing and functional recovery with no complication at the donor site as well. Flap complications were recorded in 18 (21.4%) out of 84 cases. Partial or tip necrosis occurred in six (7%) and complete
Figure 10
843
Site of soft tissue defect.
Complications.
necrosis occurred in eight (9.5%) cases. Flap necrosis was clinically attributed to venous congestion in six cases of complete loss. While in two cases, there was a technical mistake that pedicle was not positioned as a central part of the flap. Necrotic flaps were debrided out. Out of eight patients, six underwent cross leg flaps and two had below knee amputation. Partial necrosis, which was observed in six (7%) cases was debrided and secondary closure was done in three patients while split thickness skin graft in rest of three cases. Four flaps with partial necrosis were transposed to the heel and rest of two to the distal tibia. Out of 18 cases, four (4.7%) showed the minimal infection, which was treated with adequate antibiotic coverage (Fig. 11). Infection, which occurred in two diabetic patient was controlled with antibiotics but healing time was prolonged up to 3–4 weeks in contrast to 2 weeks in normal young patients. In all cases the donor site showed uneventful recovery with complete healing of the skin graft. All patients were ultimately able to have full weight bearing and shoe wearing within 2 months.
Discussion Reconstruction of soft tissue defects at the calcaneal, ankle and malleolar region has been quite a challenging job for reconstructive surgeons. The defect can be due to tumor, trauma, atrophic and diabetic ulceration involving the underlying bone as well, resulting into exposed Achilles tendon and calcaneum. Skin grafts cannot be used to cover the exposed tendon and bones. A local flap, as a surgical solution may not be possible either because of inadequate tissue available to be moved from areas adjacent to the defect or because of limited flap mobilization. Cross leg flaps are poorly tolerated and do not bring in any additional vascularisation. Their take on the area with poor local vascularity can be very
844 uncertain.8 Similarly free vascular flaps all have number of limitations in their use as compared to distally based superficial sural artery flap for soft tissue coverage of defects in lower extremity.3,9–13 The age ranged in present study was 8–55 years with a mean of 31.5 years. There were seven children in this study, youngest being 8 years of age. All had smooth recovery, which showed that reverse sural artery flap is safe and reliable in the paediatric age group and may be used in children with success. In comparison to previous studies, the present patient population was relatively of younger age, with an average of 31.5 years. The average age in other studies was 40,10 33.9,11 33.5,12 and 54.1 years.13 In this study, trauma was the major cause of the defects in 65 (77%) patients. Among these 53 (63%) patients met road traffic accidents and 12 (14%) patients had wheel spoke injuries. This is comparable to other studies in which trauma was described as 64.7% by Yilmaz et al.,3 71.4% by Rajacic et al.,14 65% by Jeng et al.,15 88% by Fraccalvieri et al.,16 84% by Almeida et al.17 This is in contrast to the study described by Baumeister et al.,13 in which unstable/chronic ulcers was the dominant causative factor in 75% of patients, and pressure sores in 45% cases as described by Touam et al.18 Masqulet et al.1 reported the concept of a neuroskin flap in 1992 and later Yilmaz et al.3 modified the technique, but were uncertain as to how large a flap could be elevated successfully. However, Yilmaz et al.3 reported that the largest flap used in their series measured 12 cm in width and 15 cm in length. The maximum dimension of the flap in present study was 12!15 cm2, which is similar to above and is comparable to other studies reported by Rasheed et al.10 and Ayyappan et al.12 The largest flap was used to cover an extensive heel defect. The success rate of sural artery flap in present study was 78.5, 16.5% of the flaps showed Partial or complete necrosis. It is comparable to study described by Rasheed et al.10 (16.6%). However, this rate is higher than the rates previously reported by Yilmaz et al.3 (12%), Rajacic et al.14 (14%), Touam et al.18 (5%). But this rate is lower than the rates reported in larger series by Baumeister et al.13 (36%), Almeida et al.17 (26.3%). The higher success rate of sural artery flap in present study is due to the fact that the sural artery flap is used in younger patients with post-traumatic defects (76%) and of distal tibia (62%). The complication rate was associated with co-morbidity as described in other studies.13–15 A study conducted by Baumeister et al.13 described venous insufficiency, arteriosclerosis and diabetes
S. Akhtar, A. Hameed as an ‘unhappy triad’. Statistically two of three flaps are prone to necrosis if at least one of these risk factors is present and every flap will be necrotic if all three factors are present.13–15 There were only six patients who had diabetes mellitus of short duration in this study. Infection occurred in two diabetic patients and was controlled. So because of low co-morbid condition of the patients in present series, flap necrosis rate is low. The Reverse sural artery flap is a useful flap for defect reconstruction in the distal leg, ankle and heel. The advantage of distally based fasciocutaneous sural flap is that it can reach the ankle and the calcaneal areas due to long pedicle and is easy and relatively quicker to elevate. Furthermore, there is no sacrifice of major arteries; it can be created in single stage with no need of microsurgical technique. The procedure is associated with minimal blood loss with maximum duration of only up to 2 h. There is no significant morbidity at the donor site.10 The major problem encountered with the reverse sural artery flap is its unreliability. It may be compromised by venous congestion and peripheral arterial insufficiency when the flap is transferred with its pedicle tunnelled subcutaneously. We recommend that sural nerve and deep fascia must be taken with the flap to raise it more safely. The pedicle should be mobilised enough to allow adequate rotation. When risk of compression is noted then pedicle should be laid open instead of transporting through a tunnel and exposed pedicle should be skin grafted. However, these are insensate flaps and sacrifice of sural nerve leads to hypoaesthesia at the lateral part of the foot. The sensitivity improves if other nerves are intact.10 Donor site shows minimal depression deformity in the early postoperative period. With time contour deformity becomes less prominent. In few cases, the donor site may have unacceptable scarring especially in women.3,10 The distally based superficial sural artery flap is a versatile, relatively simple procedure, useful in reconstruction of lower third leg, heel, malleoli and hind foot defects because of the long vascular pedicle. The surgical technique is safe, of short duration and provides alternative to microsurgical reconstruction.
References 1. Masquelet AC, Romana MC, Wolf G. Skin island flaps supplied by the vascular axis of the sensitive superficial nerves: anatomic study and clinical experience in the leg. Plast Reconstr Surg 1992;89:1115–21.
Versatility of the sural fasciocutaneous flap in the coverage of lower third leg and hind foot defects 2. Ponten B. The fasciocutaneous flap: its use in soft tissue defects of the lower leg. Br J Plast Surg 1981;34:215. 3. Yilmaz M, Karatas O, Barutcu A. The distally based superficial sural artery island flap: clinical experiences and modifications. Br J Plast Surg 1998;102:2358–67. 4. Jeng SF, Wei FC. Distally based sural artery island flap for foot and ankle reconstruction. Plast Reconstr Surg 1997;99: 744. 5. Donski PK, Fogdestam I. The distally based fasciocutaneous flap from sural region: a preliminary report. Scand J Plast Reconstr Surg 1983;17:191. 6. Haertsch PA. The blood supply of the skin of leg: a postmortem investigation. Br J Plast Surg 1981;34:470–7. 7. Coert JH, Dellon AL. Clinical implications of surgical anatomy of the sural nerve. Plast Reconstr Surg 1994;94: 850. 8. Oberlin C, Azoulay B, Batia A. The posterolateral malleolar flap in the ankle. Plast Reconstr Surg 1995;96:400. 9. Fourn BL, Caye N, Pannier M. Distally based sural fasciomuscular flap: anatomic study and application for filling leg or foot defects. Plast Reconstr Surg 2000;107:67–72. 10. Rashid M, Masood T, Hameed S, Sarwar SR. Superficial sural artery flap: a simple solution for difficult heel defects. JCPSP 2001;11:319–23.
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11. Hollier L, Sharma S, Babigumira E, Klebuc M. Versatility of the sural fasciocutaneous flap in the coverage of lower extremity wounds. Plast Reconstr Surg 2002;110:1673–9. 12. Ayyappan T, Chadha A. Super sural neurofasciocutanous flaps in acute traumatic heel reconstructions. Plast Reconstr Surg 2001;109:2307–24. 13. Baumeister SP, Spierer R, Erdmann D, Sweis RL, Levin S, Germaan GK. A realistic complication analysis of 70 sural artery flaps in a Multimorbid Patient Group. Plast Reconstr Surg 2003;129–42. 14. Rajacic N, Darweesh M, Jayakrishnan K, Gang RK, Jojic S. The distally based superficial sural flap for reconstruction of the lower leg and foot. Br J Plast Surg 1996;49:383. 15. Jeng SF, Wei FC. Distally based sural island flap for foot and ankle reconstruction. Plast Reconstr Surg 1997;99:744. 16. Fraccalvieri M, Verna G, Dolcet M, et al. The distally based superficial sural flap: our experience in reconstructing the lower leg and foot. Ann Plast Surg 2000;45:132. 17. Almeida MF, daCosta PR, Okawa RY. Reverse-flow island sural flap. Plast Reconstr Surg 2002;109:583. 18. Touam C, Rostoucher P, Bhatia A, Oberlin C. Comparative study of two series of distally based fasciocutaneous flaps for coverage of the lower one-fourth of the leg, the ankle and the foot. Plast Reconstr Surg 2001;107:383.
Versatility of the sural fasciocutaneous flap in the coverage of lower third leg and hind foot defects Shaheen Akhtar*, A. Hameed Department of Plastic and Reconstructive Surgery, Shaikh Zayed Postgraduate Medical Institute, Lahore, Pakistan Received 20 November 2005; accepted 28 December 2005
KEYWORDS Sural; Fasciocutaneous; Marjolin; Tendo-achillis
Summary Background: Reconstruction of soft tissue defects of the lower third of the leg, the heel and the hind foot remains a challenge. The distally based sural artery fasciocutaneous flap has been used effectively to resurface these defects. In many instances, it has obviated the need for free tissue transfer. Objective: The objective of the study is to evaluate the efficacy of reverse sural artery fasciocutaneous flap for coverage of lower third leg, posterior heel, malleoli and hind foot. Study design: This is a descriptive study, which was conducted on 84 patients who presented with soft tissue defects in the area of lower third leg, heel, malleoli and hind foot. Place and duration of study: The study was conducted at department of plastic and reconstructive surgery, Federal Postgraduate Medical Institute Shaikh Zayed Hospital Lahore, over a period of 7 years from February 1997 to February 2005. Patients and methods: Over a period of 7 years, a total of 84 patients with Soft tissue defect of lower third leg, heel, malleoli and hind foot were included. Preoperative data, the age and sex of each patient, cause and site of defect, dimension of flap, transposition of pedicle (through a tunnel or laid open and covered with a skin graft), postoperative results and complications were recorded. All patients were followed up in out patients department for 6 months. Results: Out of 84 patients, 54 were males and 30 females. Their ages ranged from 8 to 55 years with a mean of 31 years. Road traffic accidents was the cause of the defects in 53 patients, wheel spoke injury in 12 patients, trophic ulcer in five patients, osteomyelitis in five patients, marjolin ulcer in seven patients and diabetic ulcer in two patients. The site of 84 defects comprised 52 distal tibia; 20 tendoAchillis and posterior heel defects; seven-malleolar region; three-anterior ankle and two-foot amputation stumps. The dimension of flap ranged from 5 to 15 cm in length and 4 to 12 cm in width. Postoperatively 66 flaps survived completely while marginal necrosis was seen in six patients and infection in four patients. The complete flap necrosis occurred in eight
* Corresponding author. Address: Shaikh Zayed Hospital, Room No 12, 2nd Floor Lady Doctor’s Hostel, Lahore, Pakistan. Tel.: C92 300 4317423. E-mail addresses: [email protected] (S. Akhtar), [email protected] (A. Hameed).
S0007-1226/$ - see front matter q 2006 The British Association of Plastic Surgeons. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.bjps.2005.12.009
840
S. Akhtar, A. Hameed patients. There was no considerable morbidity at donor site and all patients had satisfactory functional outcome. Conclusions: The distally based superficial sural artery flap is a versatile, reliable procedure, useful in reconstruction of lower third leg, heel, malleoli and hind foot defects. The surgical technique is safe, of short duration and provides alternative to microsurgical reconstruction. q 2006 The British Association of Plastic Surgeons. Published by Elsevier Ltd. All rights reserved.
The reconstruction of soft tissue defects of lower third of the leg, Achilles tendon, malleoli, ankle, and calcaneal area presents a challenging problem for reconstructive surgeon because of paucity of local cutaneous, fasciocutaneous and muscle flaps in this area. Trauma and other deforming processes can involve soft tissue, underlying bone, ligamentous structures and defects that expose the tendon and bone directly. The heel is a weight bearing area, and this area is traumatized frequently. In addition, the skin over these areas is tight and has poor circulation. There are many possible reconstructive options, including skin grafts, local flaps, distant flaps and free flaps but their usage is limited and problems exist in these regions. Skin grafts are not suitable to cover the exposed bone, tendon, malleoli, heel, and weight bearing areas. Absence of peripheral pulses, diabetes, and peripheral vascular thromboses are contraindications to local flaps. Free tissue transfers provide excellent tissue coverage but require a microvascular team and equipment. In addition free tissue transfers are lengthy procedures. A better knowledge of the cutaneous blood supply from the neurovascular axis has allowed the creation and usage of distally based neurocutaneous flap of sural nerve. The concept of ‘neuroskin island flap’, developed by Masquelet et al., is well accepted.1 Such flaps are based on the cutaneous branches of the vascular axis around a superficial sensory nerve. The distally based sural fasciocutaneous flap, perfused by the lower peroneal septocutaneous perforators is based on this concept. It has been described for the reconstruction of soft tissue defects of lower leg, foot and ankle by many authors, who studied and exploited its usefulness.2–5
Surgical anatomy The superficial sural artery arises from the popliteal artery. The artery courses posteriorly for 2–3 cm before joining the sural nerve, descending between the two heads of the gastrocnemius muscle; it
follows the lateral edge of Achilles tendon. The artery courses along the sural nerve and intimately connected to it has an important role in the blood supply of the skin flap in the lower and middle third leg.3,6 It is either terminates or anastomoses with the supramalleolar branch of peroneal artery and posterior tibial artery. The artery gives off many arteria nervosum to the sural nerve with septocutaneous perforators. Usually paired venae comitantes travel with the superficial sural artery. Approximately four to eight fasciocutaneous perforators arising from the peroneal artery and venae comitantes follow the course of the crural fascia, they give rise to several branches that communicate with adjacent perforators, forming an interconnecting vascular plexus on crural fascia. The plexus extends from the posterior margin of the lateral malleolus to the superior part of the leg. Multiple communications exist between this fascial network and superficial sural artery and the overlying subcutaneous and subdermal plexus. The connection between the septocutaneous vessels form a rich suprafascial plexus with longitudinally oriented arcades. Larger perforator is often located approximately 5 cm superior to the lateral malleolus. The sural nerve descends in close association with the lesser saphenous vein, passing posterior to the lateral malleolous to supply the lateral side of the foot and fifth toe. This nerve is supplied by the superficial sural artery in the proximal one-third of leg. The distal two-thirds of the nerve is supplied by the fasciocutaneous branches of the peroneal artery. These branches course along the upper surface of the crural fascia for a variable distance before supplying the nerve; consequently, a longitudinal strip of fascia must be harvested with the nerve. In addition, the sural nerve has also intrinsic blood supply. The intrinsic system consists of epineural, perineural and endoneural vessels, longitudinally oriented with multiple levels of communication. This system has a connection with the superficial sural artery and fasciocutaneous branches of the peroneal artery.1,7
Versatility of the sural fasciocutaneous flap in the coverage of lower third leg and hind foot defects
841
The lesser saphenous vein takes its origin from the lateral extension of the dorsal venous arch of foot. It passes posteriorly to the lateral malleolus accompanied by the sural nerve. AT the junction of the distal and middle third of the leg, the lesser saphenous vein is located more medially and follows the course of the sural nerve.
Surgical techniques The flap is approached with the patient in prone position. The pneumatic tourniquet is used during flap elevation. Debridement of recipient area is done (Fig. 1) Marking is done with a line drawn from a point midway between the Achilles tendon and the lateral malleolus to the midline between two heads of the gastrocnemius muscle (Fig. 2). This roughly delimeates the course of sural nerve. After that attention is focused to mark the larger peroneal perforator, which is often located approximately 5 cm superior to the tip of the lateral malleolus. The template of the defect of recipient area is made. The flap is then outlined and centred over the sural nerve. This flap can be located anywhere in the lower two-thirds of the posterior aspect of the leg according to the need of pedicle length. An incision is made along the superior border of the flap (Fig. 3). At mid calf, the sural nerve and lesser saphenous vein are identified suprafascially (Fig. 4). The sural nerve, artery and lesser saphenous vein are divided and ligated, and included within the flap. The dissection is then continued around the distal aspect of the flap in the subfascial plane. Musculocutaneous perforators from the underlying gastrocnemius muscle are identified and coagulated. Distally a longitudinal strip of the fascia and subcutaneous fascial pedicle,
Figure 1
Soft tissue defect on medial malleolus.
Figure 2
Marking of flap.
which includes the sural nerve and lesser saphenous vein, is elevated with a width of 2–3 cm to protect the neurovascular axis. The lateral extent of dissection is up to fibula and on medial extent is the lateral border of Achilles tendon. The dissection is stopped 5 cm above the lateral malleolus where perforators from the peroneal artery communicate with the vascular plexus. The pivot point of the flap is also 5 cm above the tip of lateral malleolus. The flap is now transposed through a subcutaneous tunnel to the recipient area over a corrugated drain (Figs. 5 and 6). If there is any risk of compression of the pedicle, division of the skin bridge between the donor site and the defect is done. In these cases, pedicle is usually covered with a split thickness skin graft. The donor site is then covered with a split thickness skin graft (Fig. 7). A full-leg posterior splint with wellpadded dressing is applied making sure that there is no compression on the pedicle. The flap is left exposed for observation. The dressing is changed on 5th postoperative day. The flap usually heals by 3rd
Figure 3
Start of dissection.
842
S. Akhtar, A. Hameed
Figure 4
Figure 6
Dissected pedicle.
week but full weight bearing on flaps used for heel defects is postponed up to 6th week.
Patients and methods This study was conducted at department of plastic and reconstructive surgery, Federal Postgraduate Medical Institute Shaikh Zayed Hospital Lahore, over a period of 7 years during February 1997 to February 2005. It included 84 patients with Soft tissue defects of lower third leg, around the heel and ankle and hind foot. The age and sex of each patient, cause and site of defect, dimension of flap, transposition of pedicle (through a tunnel or laid open and covered with a skin graft), postoperative results and complications were recorded. There were six patients who had diabetes mellitus of short duration, which was controlled preoperatively with a sliding scale of insulin. X-rays of the recipient site were done in all cases to evaluate the condition of
Figure 5 Flap transposed to recipient site (medial malleolus).
Flap with the drain.
the underlying bone and to rule out osteomyelitis. The external fixator in post-traumatic patients was readjusted, if required. All patients were followed up in out patients department for 6 months. The setting of the flap and functional out come was recorded.
Results Over a period of 7 years during February 1997 to February 2005, a total of 84 flaps were performed in 84 patients. Fifty-four patients were male and 30 were female. Their ages ranged from 8 to 55 years with a mean age of 31 years (Fig. 8). There were seven children. Road traffic accidents was the cause of the defects in 53 (63%) patients, wheel spoke injury in 12 (14%) patients, trophic ulcer in five (6%) patients, osteomyelitis in five (6%) patients, Marjolin ulcer in seven (8.5%) patients and diabetic ulcer in two (2.5%) patients (Fig. 9). The site of 84 defects comprised 52 (62%) distal tibia; 20 (24%) tendo-
Figure 7
Donor site and pedicle covered with graft.
Versatility of the sural fasciocutaneous flap in the coverage of lower third leg and hind foot defects
Figure 8
Age distribution.
Figure 11
Figure 9
Etiology.
achillis and posterior heel defects; seven (8.5%) malleolar region; three (3.5%) anterior ankle and two (2.5%) foot amputation stumps (Fig. 10). In all cases, defects were covered with reverse sural island flap with an addition of skin graft in 15 patients. The dimension of the flap ranged from 5 to 15 cm in length and from 4 to 12 in width. The mean length was 10 cm and width measured 8 cm. The largest flaps were transposed to posterior heel defects and foot amputation stumps. All flaps were island flaps. Forty-eight flaps were transposed to the recipient site through a tunnel, while pedicle of 36 flaps was laid open and covered with split thickness skin graft. Out of 84 flaps; 66 (78.5%) showed the complete healing and functional recovery with no complication at the donor site as well. Flap complications were recorded in 18 (21.4%) out of 84 cases. Partial or tip necrosis occurred in six (7%) and complete
Figure 10
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Site of soft tissue defect.
Complications.
necrosis occurred in eight (9.5%) cases. Flap necrosis was clinically attributed to venous congestion in six cases of complete loss. While in two cases, there was a technical mistake that pedicle was not positioned as a central part of the flap. Necrotic flaps were debrided out. Out of eight patients, six underwent cross leg flaps and two had below knee amputation. Partial necrosis, which was observed in six (7%) cases was debrided and secondary closure was done in three patients while split thickness skin graft in rest of three cases. Four flaps with partial necrosis were transposed to the heel and rest of two to the distal tibia. Out of 18 cases, four (4.7%) showed the minimal infection, which was treated with adequate antibiotic coverage (Fig. 11). Infection, which occurred in two diabetic patient was controlled with antibiotics but healing time was prolonged up to 3–4 weeks in contrast to 2 weeks in normal young patients. In all cases the donor site showed uneventful recovery with complete healing of the skin graft. All patients were ultimately able to have full weight bearing and shoe wearing within 2 months.
Discussion Reconstruction of soft tissue defects at the calcaneal, ankle and malleolar region has been quite a challenging job for reconstructive surgeons. The defect can be due to tumor, trauma, atrophic and diabetic ulceration involving the underlying bone as well, resulting into exposed Achilles tendon and calcaneum. Skin grafts cannot be used to cover the exposed tendon and bones. A local flap, as a surgical solution may not be possible either because of inadequate tissue available to be moved from areas adjacent to the defect or because of limited flap mobilization. Cross leg flaps are poorly tolerated and do not bring in any additional vascularisation. Their take on the area with poor local vascularity can be very
844 uncertain.8 Similarly free vascular flaps all have number of limitations in their use as compared to distally based superficial sural artery flap for soft tissue coverage of defects in lower extremity.3,9–13 The age ranged in present study was 8–55 years with a mean of 31.5 years. There were seven children in this study, youngest being 8 years of age. All had smooth recovery, which showed that reverse sural artery flap is safe and reliable in the paediatric age group and may be used in children with success. In comparison to previous studies, the present patient population was relatively of younger age, with an average of 31.5 years. The average age in other studies was 40,10 33.9,11 33.5,12 and 54.1 years.13 In this study, trauma was the major cause of the defects in 65 (77%) patients. Among these 53 (63%) patients met road traffic accidents and 12 (14%) patients had wheel spoke injuries. This is comparable to other studies in which trauma was described as 64.7% by Yilmaz et al.,3 71.4% by Rajacic et al.,14 65% by Jeng et al.,15 88% by Fraccalvieri et al.,16 84% by Almeida et al.17 This is in contrast to the study described by Baumeister et al.,13 in which unstable/chronic ulcers was the dominant causative factor in 75% of patients, and pressure sores in 45% cases as described by Touam et al.18 Masqulet et al.1 reported the concept of a neuroskin flap in 1992 and later Yilmaz et al.3 modified the technique, but were uncertain as to how large a flap could be elevated successfully. However, Yilmaz et al.3 reported that the largest flap used in their series measured 12 cm in width and 15 cm in length. The maximum dimension of the flap in present study was 12!15 cm2, which is similar to above and is comparable to other studies reported by Rasheed et al.10 and Ayyappan et al.12 The largest flap was used to cover an extensive heel defect. The success rate of sural artery flap in present study was 78.5, 16.5% of the flaps showed Partial or complete necrosis. It is comparable to study described by Rasheed et al.10 (16.6%). However, this rate is higher than the rates previously reported by Yilmaz et al.3 (12%), Rajacic et al.14 (14%), Touam et al.18 (5%). But this rate is lower than the rates reported in larger series by Baumeister et al.13 (36%), Almeida et al.17 (26.3%). The higher success rate of sural artery flap in present study is due to the fact that the sural artery flap is used in younger patients with post-traumatic defects (76%) and of distal tibia (62%). The complication rate was associated with co-morbidity as described in other studies.13–15 A study conducted by Baumeister et al.13 described venous insufficiency, arteriosclerosis and diabetes
S. Akhtar, A. Hameed as an ‘unhappy triad’. Statistically two of three flaps are prone to necrosis if at least one of these risk factors is present and every flap will be necrotic if all three factors are present.13–15 There were only six patients who had diabetes mellitus of short duration in this study. Infection occurred in two diabetic patients and was controlled. So because of low co-morbid condition of the patients in present series, flap necrosis rate is low. The Reverse sural artery flap is a useful flap for defect reconstruction in the distal leg, ankle and heel. The advantage of distally based fasciocutaneous sural flap is that it can reach the ankle and the calcaneal areas due to long pedicle and is easy and relatively quicker to elevate. Furthermore, there is no sacrifice of major arteries; it can be created in single stage with no need of microsurgical technique. The procedure is associated with minimal blood loss with maximum duration of only up to 2 h. There is no significant morbidity at the donor site.10 The major problem encountered with the reverse sural artery flap is its unreliability. It may be compromised by venous congestion and peripheral arterial insufficiency when the flap is transferred with its pedicle tunnelled subcutaneously. We recommend that sural nerve and deep fascia must be taken with the flap to raise it more safely. The pedicle should be mobilised enough to allow adequate rotation. When risk of compression is noted then pedicle should be laid open instead of transporting through a tunnel and exposed pedicle should be skin grafted. However, these are insensate flaps and sacrifice of sural nerve leads to hypoaesthesia at the lateral part of the foot. The sensitivity improves if other nerves are intact.10 Donor site shows minimal depression deformity in the early postoperative period. With time contour deformity becomes less prominent. In few cases, the donor site may have unacceptable scarring especially in women.3,10 The distally based superficial sural artery flap is a versatile, relatively simple procedure, useful in reconstruction of lower third leg, heel, malleoli and hind foot defects because of the long vascular pedicle. The surgical technique is safe, of short duration and provides alternative to microsurgical reconstruction.
References 1. Masquelet AC, Romana MC, Wolf G. Skin island flaps supplied by the vascular axis of the sensitive superficial nerves: anatomic study and clinical experience in the leg. Plast Reconstr Surg 1992;89:1115–21.
Versatility of the sural fasciocutaneous flap in the coverage of lower third leg and hind foot defects 2. Ponten B. The fasciocutaneous flap: its use in soft tissue defects of the lower leg. Br J Plast Surg 1981;34:215. 3. Yilmaz M, Karatas O, Barutcu A. The distally based superficial sural artery island flap: clinical experiences and modifications. Br J Plast Surg 1998;102:2358–67. 4. Jeng SF, Wei FC. Distally based sural artery island flap for foot and ankle reconstruction. Plast Reconstr Surg 1997;99: 744. 5. Donski PK, Fogdestam I. The distally based fasciocutaneous flap from sural region: a preliminary report. Scand J Plast Reconstr Surg 1983;17:191. 6. Haertsch PA. The blood supply of the skin of leg: a postmortem investigation. Br J Plast Surg 1981;34:470–7. 7. Coert JH, Dellon AL. Clinical implications of surgical anatomy of the sural nerve. Plast Reconstr Surg 1994;94: 850. 8. Oberlin C, Azoulay B, Batia A. The posterolateral malleolar flap in the ankle. Plast Reconstr Surg 1995;96:400. 9. Fourn BL, Caye N, Pannier M. Distally based sural fasciomuscular flap: anatomic study and application for filling leg or foot defects. Plast Reconstr Surg 2000;107:67–72. 10. Rashid M, Masood T, Hameed S, Sarwar SR. Superficial sural artery flap: a simple solution for difficult heel defects. JCPSP 2001;11:319–23.
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11. Hollier L, Sharma S, Babigumira E, Klebuc M. Versatility of the sural fasciocutaneous flap in the coverage of lower extremity wounds. Plast Reconstr Surg 2002;110:1673–9. 12. Ayyappan T, Chadha A. Super sural neurofasciocutanous flaps in acute traumatic heel reconstructions. Plast Reconstr Surg 2001;109:2307–24. 13. Baumeister SP, Spierer R, Erdmann D, Sweis RL, Levin S, Germaan GK. A realistic complication analysis of 70 sural artery flaps in a Multimorbid Patient Group. Plast Reconstr Surg 2003;129–42. 14. Rajacic N, Darweesh M, Jayakrishnan K, Gang RK, Jojic S. The distally based superficial sural flap for reconstruction of the lower leg and foot. Br J Plast Surg 1996;49:383. 15. Jeng SF, Wei FC. Distally based sural island flap for foot and ankle reconstruction. Plast Reconstr Surg 1997;99:744. 16. Fraccalvieri M, Verna G, Dolcet M, et al. The distally based superficial sural flap: our experience in reconstructing the lower leg and foot. Ann Plast Surg 2000;45:132. 17. Almeida MF, daCosta PR, Okawa RY. Reverse-flow island sural flap. Plast Reconstr Surg 2002;109:583. 18. Touam C, Rostoucher P, Bhatia A, Oberlin C. Comparative study of two series of distally based fasciocutaneous flaps for coverage of the lower one-fourth of the leg, the ankle and the foot. Plast Reconstr Surg 2001;107:383.