Distally Based Posterior Tibial Artery Cross-Bridge Flap: Old Wine in a New Bottle?

We read with great interest the article by Li and coworkers on posterior tibial artery (PTA) cross-bridge flaps.[1] Over a 1.5-year period, the authors performed distally based PTA cross-bridge flaps for coverage of contralateral leg soft tissue defects in nine patients. The flap described by the authors involved raising an island skin paddle based on the cutaneous perforators of the PTA and then dissecting the source vessel to gain length. Subsequently, the PTA is divided proximally, and the flap is transposed to cover the contralateral leg defect with the pedicle tunneled subcutaneously. Both the legs were next fixed in a “cross position” by an external fixator. The pedicles of all nine flaps were divided after a delay of 3 weeks. All flaps survived and provided stable cover for the contralateral leg. We compliment the authors for their extensive literature analysis and description of various advantages of the cross-bridge PTA flap as compared with a cross-bridge free flap. However, we would like to comment on certain issues.

We have, in our institution, successfully used an island PTA flap over the last 2 decades. Sharma and Kola[2] described a flap based on the PTA that could be raised proximally or distally to cover a contralateral leg defect with exposed tibia in six patients (distally based in four patients and proximally based in two patients) almost 20 years back. In their description, an island skin flap was raised deep to the deep fascia of the leg and dissected till the septum between soleus and flexor hallucis longus was reached. The PTA was dissected out and traced proximally/distally as needed while attached to the skin paddle via its perforators. All the loose areolar tissue around the vessels was taken along with the pedicle. The PTA was divided proximally/distally as required, and the pedicle was developed for ∼10 cm. After inset of the flap, the pedicle with surrounding areolar tissue was covered with a split-skin graft. The legs were placed parallel to each other and ankles were immobilized by a figure-of-eight plaster of Paris bandage, after keeping enough padding between the medial malleoli. The patient was encouraged to perform full range of knee and hip movements after 24 hours. Ten days following flap harvest, the pedicle was progressively compressed using a clamp for a period of 2 to 3 days before complete division. Out of the four distally based flaps, two survived completely and two flaps had minor necrosis. The largest flap raised measured 23 × 11 cm.

We find significant similarities in the techniques described by Li et al[1] and Sharma and Kola.[2] Hence, we would like to contest the premise of Li and his coworkers that “this is the first report of a distally based posterior tibial artery cross-bridge flap for coverage of a leg soft tissue defect.”[1] Moreover, we suspect that immobilizing the legs in a “cross fashion,” as suggested by Li et al,[1] would restrict movements at the knee and the hip leading to postoperative stiffness. This possible complication could be avoided using the technique of postoperative immobilization advocated by Sharma and Kola.[2]

We would like to conclude that distally based island PTA flap is an excellent choice for reconstructing soft tissue defects of the contralateral leg.

REFERENCES

• 1 Li F, Cai P, Fan C, Zeng B, Chai Y, Ruan H. Distally based posterior tibial artery cross-bridge flap for reconstruction of contralateral leg soft tissue defects.  J Reconstr Microsurg. 2010;  26 159-164
• 2 Sharma R K, Kola G. Cross leg posterior tibial artery fasciocutaneous island flap for reconstruction of lower leg defects.  Br J Plast Surg. 1992;  45 62-65