Case 3: Reconstruction of an extensive circumferential leg defect using a preconditioned bipedicular MS-2-TRAM Free Flap
Authors: Nicolas K. Ewerbeck, MD, BG Ludwigshafen, Germany
A 49-year-old woman was involved as a pedestrian in a car accident and overrun by a truck. At arrival in our A&E department she suffered from multiple abrasions and large hematomas on the left thigh and lower leg. The trauma CT scan showed no fractures and no further injuries. The initial surgical treatment was performed by the trauma surgeons including debridement of multiple tension blisters and drainage of hematoseromas. After 2 weeks of further conservative treatment the patient was transferred to the department of Plastic, Reconstructive and Microsurgery because of the formation of large areas of full thickness necrosis.
Before and after
Patient examination
The patient was transferred to the department of Plastic, Reconstructive and Microsurgery because of the formation of large areas of full thickness necrosis.
- Radical full thickness necrectomy was performed and continuous negative pressure dressings were applied. The result was a circumferential defect stretching from the upper thigh to the proximal lower leg measuring approximately 70cm in length with exposure of the knee, the patella and proximal tibia.
Pre-Operative Considerations
Soft tissue reconstruction with the need to cover the exposed structures was necessary. Furthermore the contour of the leg should be restored preventing later scar formation with consecutive impairment of the mobility.
- Proposed treatment Plan: -CT angiography of the abdominal perforators and the leg to ensure good vascularity. Otherwise an AV-loop would be needed. -Ischemic preconditioning of the abdominal flap to secure perfusion of the most distal flap areas. -All areas that cannot be covered with the abdominal flap should be treated with a dermis substitute (Novosorb BTM)
- Classic free flaps to cover large body areas are usually sacrificing major muscles e.g. the combined latissimus dorsi and parascapular flap. During recovery the patient was expected to need the help of crutches for mobilization. Therefore the latissimus dorsi flap was not our first choice. Significant skin access was available at the patient’s abdomen measuring 78×22 cm. The whole flap would be needed to cover the defect and the exposed structures. Recipient vessels would be required at the leg matching the pedicles of the abdominal flap.
- Preoperative imaging: -MR Angio of the leg: vascular status = normal vascularity with a three-vessel supply on the left lower leg was found. -CT Angio: abdominal wall perforator display
Step 1: Debridement and Decision Making
Radical full thickness necrectomy was performed and continuous negative pressure dressings were applied. The result was a circumferential defect stretching from the upper thigh to the proximal lower leg measuring approximately 70cm in length with exposure of the knee, the patella and proximal tibia.
Step 2: Ischemic preconditioning
In order to ensure perfusion throughout the whole flap dimensions, ischemic preconditioning of the abdominal flap was done as an initial step 10 day prior to the final surgery. Marking the planned flaps (22x78cm). The flap was incised cranially and laterally and raised from lateral to medial up to the semilunar line. Caudally the incision was carried out to the lateral region of the SIEV.
Step 3: Transplantation of the flap – Preparation of the lower leg and thigh
Preparation of the thigh: Mobilization of the M. sartorius in a posterior direction, transection of the vastoadductoria membrane between the M. vastus medialis and M. adductor longus and exposure of the femoral arteria and vein up to 6 cm
- Preparation of the lower leg: Exposure A./V. tibialis anterior between M. tibialis anterior and M. extensor dig. longus up to 4 cm
Step 4: Transplantation of the flap – Preparation of the abdomen
Completion of the incision and preparation of the SIEV on both sides over a length of 8cm Raising of the flap by dissection from lateral to medial and preparation of all perforating vessels
- ICG measurement of the abdominal flap: with overall good perfusion. Lateral resection of a 5cm strip of subcutaneous fat tissue below the Scarpa fascia due to partial hypoperfusion
Step 5: Transplantation of the flap – Preparation of the abdomen
Dissecting the vessels through the rectus abdominis muscle with a small muscle cuff on both sides (right: 3×5 cm, left 2x4cm)
Step 6: Transplantation of the flap – Positioning of the flap on the ventral left extremity
Left pedicle: 1x arterial end to end anastomosis to the ant. tibial artery and 1x venous end to end anastomosis the accompanying vein with a 3.5mm coupler. Right pedicle: 1x arterial end to side anastomosis to the superf. femoral artery and 1x venous end to side anastomosis to the accompanying vein.
Step 7: Transplantation of the flap – Applying Novosorb BTM to the dorsal aspect of the leg
All areas that cannot be covered with the abdominal flap should be treated with a dermis substitute (Novosorb BTM).
Post-Operative Plan
Hourly perfusion checks for 5 days postoperatively Coagulation management Delamination of Novosorb BTM and split skin grafting Mobilization (physiotherapy) Planning of follow-up treatment (rehabilitation)
- During recovery the patient was expected to need the help of crutches for mobilization. Therefore the latissimus dorsi flap was not our first choice. Significant skin access was available at the patient’s abdomen measuring 78×22 cm. The whole flap would be needed to cover the defect and the exposed structures. Recipient vessels would be required at the leg matching the pedicles of the abdominal flap.
- In order to ensure perfusion throughout the whole flap dimensions, ischemic preconditioning of the abdominal flap was done as an initial step 10 day prior to the final surgery
- Classic free flaps to cover large body areas are usually sacrificing major muscles e.g. the combined latissimus dorsi and parascapular flap. During recovery the patient was expected to need the help of crutches for mobilization. Therefore the latissimus dorsi flap was not our first choice. The whole flap would be needed to cover the defect and the exposed structures. Recipient vessels would be required at the leg matching the pedicles of the abdominal flap.
- CT angiography of the abdominal perforators and the leg to ensure good vascularity. Otherwise an AV-loop would be needed.
- Patient information and consent: Risk of partial or total free flap loss, donor-site complication (seroma, haematoma, bulging, hernia, abdominal wall insufficiency, loss of strength), monitoring of the flap.