Proximal Foot and Sole Soft Tissue Defect Reconstruction with Distally Based Pedicle Flaps: An Approach with Hyperbaric Oxygen Therapy as a Tool

Various techniques ranging from a skin grafting to free-tissue transfer, have been used to reconstruct the soft tissue defect of the sole and proximal foot regions although only few have yielded entirely satisfactory results[1].A safe, easy and reliable reconstructive option must be available for the reconstruction of thelower third leg and foot region. The lateral supramalleolar flap[2,3]is raised on the lateral aspect of the lower leg and the flap is vascularized by a perforating branch of the dorsal peroneal artery. The lateral supramalleolar flap is commonly used for coverage that includes the whole dorsum of the foot, the medial and the lateral arches and all the regions of the heel. The reverses Ural flap[4,5] is raised on the posterior aspect of the calf, and the anatomical structures included in the pedicle are the superficial and deep fascias, the sural nerve, the lesser saphenous vein and the superficial sural artery. Reverse sural flap is commonly used for coverage of the hind foot, dorsum and the region of the lateral malleolus. In this prospective study, along with the distally based flap cover for soft tissue defect over the lower third leg and foot region. Hyperbaric oxygen therapy was utilized as an adjunct to preserve marginal tissue, treat compartment syndrome and aid flap delay for the soft tissue reconstruction of foot and lower third leg. The aim of the study is to know the effectiveness of hyperbaric oxygen therapy as an adjunct for flap coverage.

Sixteen patients with soft tissue defect of foot and lower third leg region were treated over a period of 7 months (December 2012 to June 2013). Ethical clearance for the study was obtained from the Institution. Proper Informed consent was obtained from the patient participating in the study. Patients were informed about the line of management, possible treatment modalities, need for additional surgical procedures pertaining the pattern of injuries. Thorough wound debridement, fixation of fractures and planning of reconstruction was done. If the wound was fit for flap cover then immediate reconstruction was performed. Hyperbaric oxygen therapy was initiated during the immediate post-operative period. A session of six hyperbaric oxygen therapy, one session extending to 1hr for six days was administered to the patients post operatively. Severity of injury, time of referral, comorbid condition, age of the patients, reach of the flap were considered as factors to subject the patient for flap delay with associated hyperbaric oxygen therapy. In case of extended reverse sural flap, after initial debridement, priming was planned with hyperbaric oxygen therapy. On post debridement day 2, flap delay was done and flap inset was completed on post debridement day 4. Hyperbaric oxygen therapy sessions were administered extending to 6-12 sessions accordingly depending on the flap healing status.Immobilization of the limb was done all patients for three weeks. Outcome following different types of management and secondary procedures performed were noted.

Surgical technique

The perforating branch of the peroneal artery for lateral supramalleolar fasciocutaneous flap pierces the interosseous membrane at the distal tibio-fibular angle about 5 cm proximal to the tip of the lateral malleolus. The lateral supramalleolar flap contains the superficial peroneal nerve, the perforating branch from the peroneal artery and the venae comitantes.

The reverse sural flap was outlined at the junction of the two heads of the gastrocnemius muscle. A line of incision was marked over the presumed course of the sural nerve and the lesser saphenous vein. The pivotal point of the pedicle was 5-7cm proximal to the tip of the lateral malleolus. Marking up the perforators with handheld Doppler will help in adjusting the pivotal point at appropriate level to preserve vascularity to the flap. The flap was raised including the fascia. When planned for extended reverse sural flap, fascia in between the gastrocnemius muscle was preserved. Extended reverse sural flaps done in the series were always delayed. Flap was delayed if the territory of the flap exceeds the middle or lower third marking of the reverse sural flap or if the flap was based on upper most perforator due to the extension of zone of injury. During the first stage of delay, the flap was raised till the pedicle region and kept in position. During the second stage, flap inset was completed.

The soft tissue defect was due to trauma in 13 cases, assault in one case, tumor in one case and osteomyelitis in one case (Table 1). Of the 16 patients, 10 were males and 6 were females, with a range 13 to 72 years (mean 36.12yrs).Two patients had diabetes mellitus as co-morbid illness. Among the sixteen cases, five were chronic wounds and 11 were acute wounds. The lateral supramalleolar flap was used in 11 cases and distally based sural flap was used in 5 cases for the reconstruction of skin defects of the ankle and foot that exposed the bone or tendons. The length of the flap varied from 4 cm to 14 cm (mean 6.5 cm) and the width varied from 4 cm to 5 cm (mean 4.1 cm).. Out of sixteen cases, seven were islanded fasciocutaneous lateral supramalleolar, two was fasciocutaneous lateral supramalleolar, one was adipofascial lateral supramalleolar, one was propeller type lateral supramalleolar, three were extended reverse sural and two were island reverse sural flap in nature. Two cases had necrosis at the tip of the flap managed conservatively. Superficial necrosis developed in one lateral supramalleolar flap, but this was successfully treated by debridement and skin grafting. Except for two flaps with tip and superficial necrosis, rest of the flaps survived completely (Table 1). Functional recovery and bony union was adequate in all treated patients. We present four crucial cases which were salvaged by combination of hyperbaric oxygen therapy to flap cover. In case 1, the flap with onset of tip necrosis was salvaged.In the second case, an extended flap with association of flap delay process was salvaged using hyperbaric oxygen therapy. In third case, a patient with compartment syndrome where the chances of flap failure is high was salvaged by hyperbaric oxygen therapy and in final case, an adipofascial flap was salvaged by adjunct hyperbaric oxygen therapy.

Table 1: Representing the patients participated in the study, Flap utilized for reconstruction and outcome

Case 1

A 43yrs male admitted with crush injury to the right ankle and foot region due to road traffic accident. Patient presented with soft tissue loss over the medial aspect of the right ankle and foot region exposing the base of the first metatarsal bone and tarsometatarsal joint (Figure 1).

Figure 1: Soft tissue loss over the medial aspect of the right ankle and foot region exposing the base of the first metatarsal bone and tarsometatarsal joint.

After bony stabilization, soft tissue coverage was done with island lateral supramalleolar flap and donor site covered with split thickness skin grafting (Figure 2,3).

Figure2: Soft tissue coverage was done with island lateral supramalleolar flap.

Figure 3: Donor site covered with split thickness skin grafting.

Hyperbaric oxygen therapy was administered for 12 sessions postoperatively. Patient developed discoloration of the tip of the flap which settled down without any secondary intervention (Figure 4,5).

Figure 4: Discoloration of the tip of the flap due to venous congestion.

Figure 5: Tip discoloration settled down with conservative management with hyperbaric oxygen therapy.

Case 2

A 34 yrs male with crush injury to the right heel pad and ankle region was referred to our center after three weeks following injury. Patient presented with necrotic heel pad region with multiple lacerations over the ankle region both on medial and lateral aspect (Figure 6-8).

Figure 6: Crush injury to the right heel pad and ankle region with multiple laceration medial aspect of foot.

Figure 7: Picture showing necrotic heel pad tissue.

Figure 8: Crush injury to the right heel pad and ankle region with multiple laceration lateral aspect of foot.

Wound was debrided (Figure 9) and hyperbaric oxygen therapy sessions were started. On post debridement day 2, Extended reverse sural flap elevated and flap delay done (Figure 10, 11) continuing the hyperbaric sessions.

Figure 9: Extended reverse sural artery flap was elevated on day 2 following debridement.

Figure 10: Extended reverse sural artery flap delay done.

Figure 11: Flap inset was completed on day 4 following debridement.

On post debridement day 4, flap inset completed. Donor area covered with split thickness skin graft.Hyperbaric oxygen therapy was administered for 12 sessions. Post-operative period was uneventful (Figure 12).

Figure 12: Picture showing the flap position over the heel pad region- late post-operative period.

Case 3

A 32 yrs female admitted with crush injury of the right foot and lower third leg exposing the medial malleolus (Figure 13). Patient had an associated compartment syndrome of the leg. Wound was debrided and fasciotomy done. Island lateral supramalleolar flap was used to cover the defect over the bony region (Figure 14) and rest of the raw area was covered with skin grafting. Hyperbaric oxygen therapy was administered for 12 sessions. There was superficial tissue necrosis of the flap which was later managed by split thickness skin grafting(Figure 15).

Figure 13: Crush injury of the right foot and lower third leg exposing the medial malleolus with compartment syndrome.

Figure 14: Island lateral supramalleolar flap was used to cover the defect over the bony region.

Figure 15: Post-operative picture following skin grafting over the area of superficial necrosis of flap.

Case 4

A 40 yrs female admitted with crush injury of the right foot dorsum with soft tissue loss exposing the extensor tendons (Figure 16). Wound was debrided and adipofascial lateral supramalleolar flap was used to cover the defect. Split thickness skin graft was used to cover adipofascial flap. Hyperbaric oxygen therapy was administered for six sessions following the procedure. Post-operative period was uneventful (Figure 17).

Figure-16: Crush injury of the right foot dorsum with soft tissue loss exposing the extensor tendons.

Figure17: Adipofascial lateral supramalleolar flap was used to cover the defect. Skin grafting done over the flap.