Anatomic basis of the sural fascio-cutaneous flap: surgical applications

Hemodynamics in Distally Based Sural Flaps for Lower Leg Reconstruction: A Literature Review

Coverage of posttraumatic and chronic wounds at the distal leg is a difficult problem due to limited soft tissue available for local flaps. The sural flap is a versatile and effective method for reconstruction in this area since it does not need a significant amount of time or assistance to complete. Improving the survival of these flaps is critically dependent on understanding the basics of flap circulation and why recent modifications were introduced. This review will serve as a much-needed comprehensive analysis of these topics for surgeons looking to increase the reliability of their sural flaps.

Arteriovenous supercharging: A novel approach to improve reliability of the distally based sural flap

Complex soft-tissue defects of the distal third of the leg, foot and ankle with exposed bones/joints, tendons and implants need a flap for their closure. Distally based sural flap is commonly used, but it has a high partial necrosis rate due to venous insufficiency. We addressed this issue with AV supercharging by dorsalis pedis artery with short saphenous vein. Eight patients (seven males, mean age 34.12 years) with post traumatic lower limb defects over heel and foot were included. All flaps survived and healed although four flaps developed superficial partial epidermolysis. Average healing time was 20.12 days. Closure of the AV fistula was not required in any of the patients. At mean follow-up of two months, all patients were ambulatory with well settled flap. Arteriovenous supercharging of distally based sural flap through short saphenous vein improves the distal arterial perfusion in the flap and prevents distal flap necrosis.

Concurrent internal fixation and soft tissue reconstruction by distally based sural flap: a practicable scheme for complex distal tibial fractures

BACKGROUND

It is difficult to establish both fracture union and wound healing of open fractures complicated with soft tissue defects of the distal tibia. We describe the simultaneous use of internal fixation and soft tissue coverage by a distally based sural flap (DBSF) for these complex injuries.

METHODS

Seventeen patients with Gustilo IIIB open fractures of the distal tibia were operated on by internal fixation and DBSF coverage. Data were collected on the size of the defect, time to fixation and soft tissue coverage or 'fix & flap', types of implant, time to union, postoperative complications and objective clinical measurement.

RESULTS

The average size of the soft tissue defect after debridement was 6.4 × 8.4 cm² (range 4.0-9.0 × 6.0-12.0). The mean time to fix & flap was 8.1 days (range 7-10). A medial precontoured plate was used in 8 patients and an anterolateral precontoured plate in 9. All fractures were united in a mean duration of 22.6 weeks (range 20-28). One patient had partial flap necrosis. Using the Puno functional score, 2 patients had excellent functional outcomes and 15 patients had good functional outcomes.

CONCLUSION

Concurrent Internal fixation and soft tissue reconstruction by DBSF is effective and reproducible for Gustilo type III open fractures of the distal tibia even in cases of more than 50 cm² soft tissue defects.

True and 'choke' anastomoses between perforator angiosomes: part i. anatomical location

BACKGROUND

Reports of more than two cutaneous perforator angiosome territories being raised successfully in distally based sural flaps are appearing in the literature. Previous anatomical studies have noted that cutaneous arteries, connected by true anastomosis without change in caliber, frequently parallel cutaneous nerves.

METHODS

Twenty-four (48 sides) total body lead oxide cadaver injection studies, including seven arterial and two venous neurovascular, were examined, and the results were compared with clinical thermography in Part II.

RESULTS

Long branches of cutaneous perforators, connected in a series by true anastomoses, paralleled at variable distances the main trunks of cutaneous nerves in the head, neck, torso, and upper and lower extremities. Specifically, in the leg, an average of 3.2 true anastomoses (range, 1 to 5) connected perforators that paralleled the sural nerve on the back of the calf; and 2.5 (range, 1 to 4) connected perforators on the medial side of the leg. These vascular freeways were paralleled by the short and long saphenous veins, respectively.

CONCLUSIONS

True anastomoses frequently connect skin perforators that course in parallel with cutaneous nerves and veins. They provide an explanation for the long viable flaps noted in the leg, and it will be shown in Part II that they can be detected preoperatively with thermography.

S-shaped reverse sural flap for reconstruction of tissue defect on heel

Traumatic limb injury is a prevalent lesion in Iran. Motorcycle accidents are responsible for most of these traumatic lesions. Despite various reported techniques, the coverage of the Achilles tendon, malleoli, ankle and heel is still daunting and demanding procedure. S-shaped reverse sural flap is a modified technique of reconstruction. In this report of 6 patients underwent surgical reconstruction by this modified technique we discuss about the technique as a simple and safe technique with low morbidity rate and recommend using this technique in complex injuries.

Therapeutic management of complicated talar extrusion: literature review and case report

Total extrusion of the talus with interruption of all ligaments (missing talus) is a rare injury. We describe the case of a 27-year-old man who reported total extrusion of the talus after a motorbike accident with interruption of all talar ligaments. In the first repair effort, the articular void left by the talus was filled with antibiotic cement and the wound was closed primarily. Nevertheless, the skin overlying the talar joint displayed necrosis. In order to cover the cutaneous defect, improve local vascularization, and allow reimplantation of the talus, a sural fasciocutaneous island flap was harvested. Subsequently, the original talus was placed and arthrodesis of the subtalar joint was performed. The patient was able to walk bearing full weight without support equipment after 6 months. Several therapeutic options have been suggested in such cases, including replacing the talus, tibiocalcaneal arthrodesis, and pseudoarthrodesis. The rarity and peculiarity of such cases make the establishment of generalized guidelines an arduous task, leaving the choice of treatment to the surgeon, in conformity with each case’s peculiarity. In this case use of the flap may have promoted the vascularization of the reimplanted talus, thus avoiding avascular necrosis and allowing successful reimplantation of the original talus.

Distally based sural lesser saphenous neuro-veno-adipo-fascial (NVAF) flap for reconstruction in the foot: lessons learned

We report nine cases in which the neuro-veno-adipo-fascial (NVAF) flap was used to perform reconstruction of foot wounds over a 7-year period. Complications occurred in five (56%) patients. One patient suffered total loss of the flap and four experienced partial loss of the NVAF flap. Complications are to be expected with the use of the NVAF flap for foot wounds, but in most cases the flap is salvageable. The NVAF flap is an option in foot reconstruction when free tissue transfer is not available, contraindicated due to patient factors or when a prior free flap has failed.

Distally based sural fasciomyocutaneous flap: anatomic study and modified technique for complicated wounds of the lower third leg and weight bearing heel

The reconstruction of the distal third leg and weight-bearing heel, especially when complicated with infection and/or dead space, remains a challenge in reconstructive surgery. The distally based sural neurofasciomyocutaneous flap has been proved a valuable tool in repair of the soft tissue defects of those areas. In this report, we present the results of the anatomical study on vascular communication between the suprafascial sural neurovascular axis and the deep gastrocnemius muscle and a modified technique in clinical applications for reconstruction of the soft tissue defects in the distal lower leg and heel. Six lower limbs of fresh cadavers were injected with red gelatin and dissected. A constant vascular connection with average four musculo-fasciocutaneous perforators with diameter 0.2-0.5 mm was identified in the overlapping area between the suprafascial sural neurovascular axis and the deep gastrocnemius muscle. Based on these findings, a modified distally based sural neurofasciomyocutaneous flap including the distal gastrocnemius muscle component was designed and used for repairs of the soft tissue defects in the distal lower limb and plantar heel pad in six patients. The blood supplies of flaps comprised either the peroneal perforator and adipofascial pedicle or the peroneal perforator only. The average size of the fasciocutaneous flap was 51 cm(2), and the muscle component 17.7 cm(2). All flaps survived uneventfully. Our results suggest that this technical modification could provide wider range for applications of the distally based sural neurofasciomyocutaneous flap in repair of the soft tissue defects of the lower extremity and heel.

Principles of definitive soft tissue coverage with flaps

Despite the emergence of negative pressure wound therapy with reticulated open cell foam (NPWT/ROCF) as delivered by V.A.C.(R) Therapy (KCI, San Antonio, TX) for orthopaedic trauma, vascularized tissue transfer whether it be pedicle, free, or tissue transfer using the operating microscope or as an island, remains the mainstay of soft tissue reconstruction for orthopaedic traumatology. The critisism of microvascular procedures has been that they are lengthy, costly, and required technical expertise to perform. While technical skills are required, microsurgical care has evolved into a routine operation with high degrees of success in experienced hand. The problem that still remains is access to surgeons who are interested in soft tissue reconstruction and can perform definitive coverage with flaps. There is a need in the orthopaedic community to solve the problem of lack of flap surgeons and as a result, NPWT/ROCF has been touted as the answer to flap reconstruction. NPWT/ROCF is an important addition to soft tissue reconstruction but it serves as a bridge rather than definitive coverage in many hands. Just as wound technology is evolving with tissue substitutes, growth factors and NPWT/ROCF flaps technology continues to advance with new perforator flaps and local regional flaps, particularly the sural flap, coming on line as mainstays of soft tissue reconstruction.

The Distally Based Sural Flap

LEARNING OBJECTIVES

After studying this article, the participant should be able to: (1) Describe the anatomy of the posterior lower leg as it is relevant to the distally based sural flap. (2) Describe the basic surgical technique of the distally based sural fasciocutaneous flap. (3) Understand the common complications associated with the sural flap and their approximate incidences in both a healthy and a multimorbid patient population. (4) Describe how skin, fascia, and muscle can be used to customize the sural flap for different purposes. (5) Understand the various modifications of the sural flap that have been described in the literature.

SUMMARY

Over the past decade, the distally based sural flap has become increasingly used in reconstruction of the foot and lower leg. The rise in popularity of this flap has been paralleled by an increase in the number of cases, innovations, and technical refinements reported in the medical literature. This review summarizes the 79 publications in the English language literature on the subject of the distally based sural flap. The anatomical studies are summarized in a unified description of the relevant flap anatomy. The flap's indications and composition and a variety of modifications are described. Technical aspects are discussed and clinical insight to minimize complications is provided. In conclusion, the distally based sural flap offers an alternative to free tissue transfer for reconstruction of the lower extremity.

Modified distally based peroneal artery perforator flap for reconstruction of foot and ankle

The distally based sural fasciocutaneous flap has been used widely for reconstruction of foot and ankle soft-tissue defects. Here we report on a series of cases of foot and ankle reconstruction with a modified distally based sural flap. The vascular pedicle of the flap includes an axial perforator branch of the peroneal artery and two concomitant veins. This modified distally based perforator flap, measuring around 17 x 6 cm to 30 x 10 cm in size, was transferred for coverage of foot and ankle soft-tissue defects in 7 cases. All flaps survived completely. Neither arterial ischemia nor venous congestion was noted. As compared to other distally based sural flaps with neuro-veno-adipo-fascial pedicles, this modified sural flap with a thin perforator pedicle is easily rotated. The flap can obtain abundant blood supply through both axial perforator and longitudinal chain-linked vascular plexuses, and does not have the venous reflow problem. In conclusion, the invention of this perforator fasciocutaneous flap provides a valuable tool for repair of foot and ankle soft-tissue defects.

The venoneuroadipofascial pedicled distally based sural island myofasciocutaneous and muscle flaps: anatomical basis of a new concept

Reconstruction of soft-tissue defects of the lower third of the leg, the heel and the foot remains a challenge. The distally based sural neurocutaneous flap has been used effectively to resurface these defects. However, the paucity of bulk in this flap makes it inadequate for complex post-traumatic or post-ablative soft-tissue reconstruction. We dissected 20 freshly amputated lower limbs after injecting them with a mixture of lead oxide and gelatin. We found muscular branches of the accompanying artery of the sural nerve to the gastrocnemius muscle in all 20 limbs. This led us to conceptualise the distally based venoneuroadipofascial pedicled island sural myofasciocutaneous and muscle flaps. These flaps are useful for the reconstruction of complex soft-tissue defects of the lower third of the leg, the heel and the foot.