Vascular Supply of the Distally Based Superficial Sural Artery Flap: Surgical Safe Zones Based on Component Analysis Using Three-Dimensional Computed Tomographic Angiography:

Simplified soft tissue coverage of the distal lower extremity: The reverse sural flap

Soft tissue defects involving the distal lower extremity present challenging problems for orthopaedic surgeons to manage. Historically, wounds not amenable to primary closure have necessitated assistance from multidisciplinary teams using plastic surgeons to obtain adequate soft tissue coverage through rotational flap or free tissue transfer procedures. Techniques related to soft tissue rearrangement and local rotational flap coverage have advanced over the years with a growing knowledge of local anatomy and vasculature. The reverse sural flap may be performed to cover soft tissue defects within 10 cm of the foot or ankle region, negating the need for microvascular intervention. The simplistic nature of the reverse sural flap is appealing to orthopaedic surgeons as a means to provide timely patient care without additional support because it does not require microvasculature work or the need for intraoperative microscopes and has been popularized among orthopaedic trauma surgeons as a necessary tool to possess. Here, we discuss the reverse sural flap to include history, relevant anatomy, clinical indications, and a description of the technique for application.

Reconstruction of the weight-bearing heel with nonsensate reverse sural artery flaps

BACKGROUND

The reverse sural artery flap (RSAF) is widely used to reconstruct foot and ankle defects. Although it is commonly used in a nonsensate type, there has been controversy as to whether it provides sufficient stability and durability when applied to weight-bearing heels. The aim of this study was to evaluate patient outcomes after weight-bearing heel coverage using a nonsensate RSAF.

METHODS

Twenty-three patients who underwent reconstruction surgery of the weight-bearing heel with RSAF from 2004 to 2018 in a tertiary hospital were retrospectively reviewed. All surgeries were performed without a sensate procedure. The patients' experience of pressure sore on the flap area and the ability to use normal footwear were investigated. Light touch, Semmes-Weinstein test (SWT), and two-point discrimination tests were assessed, along with postoperative wound complications.

RESULTS

Heel damage etiologies included malignant tumors in 14 (61%), trauma-related in 7 (30%) and diabetic ulcers in 2 (9%) patients. Patient mean age was 58 years (range, 18-93 years) and the mean follow-up period was 57 months (range, 12-185 months). The mean size of the flap was 64.1 cm2 (range, 20-169 cm²). All flaps healed without major complications. All returned to daily living activities and 20 (86%) patients were able to use normal footwear. Of the 11 patients who had available measurement records, 8 (73%) showed a light touch sense. The mean SWT value was 4.31 (range, 3.61- 4.56). Two-point discrimination was not observed in any of the patients. Two patients had experienced superficial ulcers on the flap within a one-year postoperative period, which spontaneously healed and did not recur. No full-thickness ulcers were observed during the follow-up period.

CONCLUSIONS

The results of this study suggest that patients who underwent nonsensate RSAF for the reconstruction of the heel could expect to maintain the property for stable weight-bearing without pressure sore.

A Single-Center Surgical Experience With the Reverse Sural Artery Flap as a Reliable Solution for Lower Leg Soft Tissue Defects, With Minimum Two-Year Follow-Up

AIM

Small soft tissue defects of the distal tibia and hindfoot resulting from traumatic, operative, or neoplastic conditions and chronic ulcers can be successfully dealt with the use of the reverse sural artery flap (RSAF). This study aims to describe a single center's results and familiarity with this technique over a 15-year period of time.

MATERIAL AND METHODS

We retrospectively reviewed the clinical files of patients who were consecutively treated with RSAF and regularly followed up between January 1, 2004 and December 31, 2018, with a minimum postoperative follow-up period of two years. Patient demographics and comorbidities, location of the defect, performing surgeon, mean operation time, flap pedicle width, mean size of the defect, days of hospitalization following the operation, healing flap rate, and complications were recorded.

RESULTS

The sample consisted of 30 adult patients (25 men, 5 women), with a mean age of 51.07 years (16-80 years, SD 18.61). The mean operation time was 99.03 min (range 83-131, SD 10.57), and the mean size of the defect was 11.11 cm2 (range 6.1-19.4, SD 3.22). Successful flap rate (complete healing and coverage of the defect, with or without additional minor intervention) was 83.3% (25/30). Among successfully healed flaps, six patients with partial necrosis of the dermis were treated by an additional split-thickness skin graft. Five flaps failed to heal. Deep infection was present in two patients, leading to flap failure and reoperation. Serious venous congestion resulting in flap ischemia occurred in three cases. Circumferential keloid formation (not affecting successful outcome) was present in seven cases. Flap thickness approximated to normal within six months. All donor sites healed well (either by a split-thickness cutaneous flap or by immediate wound closure). Light paresthesia on the lateral border of the leg and foot disappeared within six months.

CONCLUSIONS

A single-center experience with the RSAF has yielded satisfactory clinical outcomes, and the long-term tackle with the difficult reconstruction conditions around the ankle, has led to valuable advice on surgical technique and postoperative protocol, based on an anatomical basis.

Distally Based Sural Fasciocutaneous Flaps for Reconstructing Soft Tissue Defects Proximal and Distal to the Tarsometatarsal Joints: A Comparative Analysis

Distally based sural fasciocutaneous (DBSF) flaps are widely used for reconstructing soft tissue defects of the foot. The purpose of this paper was to compare the clinical efficacy of the use of flaps to repair defects in areas proximal and distal to the level of the tarsometatarsal joints in a relatively large number of patients and to analyze the effects of factors on the risk of developing partial necrosis of the flaps. Between April 2001 and December 2019, a total of 355 DBSF flaps were utilized to cover soft tissue defects in the foot. According to the furthest location of the defects reconstructed with the flaps, the flaps were divided into the proximal foot group (n = 260) and the distal foot group (n = 95). The partial necrosis rates, their influencing factors, and the clinical outcomes of the procedure were compared between the two groups. In the proximal foot group, the partial necrosis rate (6.2%, 16 of 260) was significantly lower than that in the distal foot group (14.7%, 14 of 95) (P < .05). The proportion of successful coverage of the defects using the flaps alone or in combination with a simple salvage treatment was comparable between the groups (P > .05). The ratio of unfavorable conditions in the distal foot group was higher than that in the proximal foot group (P < .05). DBSF flaps can be effectively utilized to repair defects in the proximal and distal areas of the foot. The use of a DBSF flap to repair defects in the proximal areas of the foot is superior to the use of DBSF flaps for repairing defects in the distal areas of the foot in terms of reliable survival of the flap.

Distally Based Perforator-Plus Sural Neurocutaneous Flap with High or Low Pivot Point: Anatomical Considerations and a Retrospective Study of a Clinical Series of 378 Flaps

BACKGROUND

 This study is to describe the distribution of natural true anastomoses associated with the distally based perforator-plus sural neurocutaneous flap (sural flap), summarize our experience in the flap with high pivot point, and compare the outcomes between the flaps with high and low pivot points.

METHODS

 Five amputated lower limbs were perfused, and the integuments were radiographed. We retrospectively analyzed 378 flaps, which were divided into two groups: pivot points located ≤8.0 cm (low pivot point group) and >8.0 cm (high pivot point group) proximal to the tip of the lateral malleolus. Partial necrosis rates were compared between two groups.

RESULTS

 The arterial chain surrounding the sural nerve was linked by true anastomoses from the intermalleolar line to popliteal crease. True anastomoses existed among peroneal perforators and between these perforators and the arterial chain. There were 93 flaps with high pivot point and 285 flaps with low pivot point. Partial necrosis rates were 16 and 9.1% in the high and low pivot point group (p = 0.059), respectively.

CONCLUSION

 True anastomosis connections among peroneal perforators and the whole arterial chain around sural nerve enable the sural flap to survive with a greater length. The sural flap with high pivot point is a good option for reconstructing soft-tissue defects in the middle and distal leg, ankle, and foot, particularly when the lowest peroneal perforator presents damage, greater distance to the defects, discontinuity with the donor site, or anatomical variation.

Free neurosensory flap based on the accompanying vessels of lateral sural cutaneous nerve: anatomic study and preliminary clinical applications

BACKGROUND

The posterior aspect of the leg is an ideal donor site for flap surgery. In this study, the anatomy was investigated of the lateral sural cutaneous nerve (LSCN) and its accompanying artery, superficial lateral sural artery (SLSA), and a lateral sural neurocutaneous flap was designed.

METHODS

Five fresh adult cadaver legs perfused with red latex were dissected to observe the course and relationship between LSCN and SLSA. The outer diameter of SLSA at its origin was measured. Then a lateral sural neurocutaneous flap was designed and used to repair soft tissue defects in six patients.

RESULTS

The anatomic results showed that the SLSA gave rise to branches that followed the LSCN and ramified into terminals at the ramification of the nerve. It originated directly from the popliteal artery 4.2 ± 0.2 mm above the fibular head, where its outer diameter was 0.96 ± 0.23 mm. Several perforators penetrated from the crural fascia and anastomosed to the SLSA, creating a fine anastomotic network. The clinical results showed that the size of the flap ranged from 12 × 6 cm to 25 × 8 cm. All six flaps survived completely without complications. Follow-up ranged from 6 to 18 months with 11 months on average. The overall contour and sensory recovery of the flap were satisfied.

CONCLUSION

A free innervated flap may be elevated safely based on the LSCN and its accompanying vessels. It provides an alternative in reconstruction of soft tissue defects where sensory recovery is important.

Distally based peroneal artery perforator-plus fasciocutaneous flap in the reconstruction of soft tissue defects over the distal forefoot: a retrospectively analyzed clinical trial

BACKGROUND

Distally based peroneal artery perforator-plus fasciocutaneous (DPAPF) flaps are widely used for reconstructing soft-tissue defects of the lower extremity. However, reports on the reconstruction of the defects over the distal forefoot using the DPAPF flaps are scarce. Herein, we describe our experience on the reconstruction of these defects using DPAPF flaps in a considerable sample size.

METHODS

Between February 2005 and August 2019, a total of 56 DPAPF flaps in 56 patients were used to reconstruct soft-tissue defects in the forefoot. In order to reduce the length of fascial pedicle and the total length of the DPAPF flaps, the ankles were fixed in dorsiflexion using a Kirschner wire before designing the flaps. The flaps were elevated by the anterograde-retrograde approach. Patient factors and flap factors were compared between the "survival" and "partial necrosis" groups.

RESULTS

Overall, 47 flaps had survived completely in one stage. Partial necrosis developed in nine flaps, with only one remnant defect covered using a local flap. By fixing the ankles in dorsiflexion, the length of the fascial pedicle was reduced approximately 2.35 ± 0.58 cm, the total length of the flap was simultaneously shortened by the same amount as the length of the fascial pedicle. The width of the fascia pedicle varied from 3.0 cm to 6.0 cm. The fascial pedicle width > 4 cm was found in 21 flaps. The partial necrosis rate of the DPAPF flaps with the top edge located in the 8th zone was significantly lower than that in the 9th zone (p < 0.05).

CONCLUSIONS

The DPAPF flaps can be effectively used to reconstruct the defects over the distal forefoot because of convenient harvest and reliability. By fixing the ankle in dorsiflexion with Kirschner wire and widening the fascial pedicle appropriately, the top edge and LWR of the flaps will be decreased, and thus the procedures are helpful for the flaps survival.

[The "racket-like" flap: Method to increase the reliability of the sural neuro-cutaneous flap]

We realized a retrospective study from 2003 to 2018 comparing two surgical techniques of neuro-fascio-cutaneous sural flap harvesting to improve their reliability: the "vascular pedicle tunneling" method and the "racket-like" flap method. There are 35 flaps in this series from lower distal limb reconstruction: 21 "racket-like" flaps and 14 "tunneling-pedicle" flaps. There were no partial or total necrosis case in the "racket-like" flaps group. Our technique reduces covering failure due to partial or total necrosis risk with a statistically significant impact. We propose to extend the "racket-like" technique to every fascio-cutaneous flap available.

Use of the cross-leg distally based sural artery flap for the reconstruction of complex lower extremity defects

Cross-leg flaps are a useful reconstructive option for complex lower limb defects when free flaps cannot be performed owing to vessel damage. We describe the use of the extended distally based sural artery flap in a cross-leg fashion for lower extremity coverage in three patients. To maximise the viability of these extended flaps, a delay was performed by raising them in a bipedicled fashion before gradual division of the tip over 5 to 7 days for cross-leg transfer. Rigid coupling of the lower limbs with external fixators was critical in preventing flap avulsion and to promote neovascular takeover. The pedicle was gradually divided over the ensuing 7 to 14 days before full flap inset and removal of the external fixators. In all three patients, the flaps survived with no complications and successful coverage of the critical defect was achieved. One patient developed a grade 2 pressure injury on his heel that resolved with conservative dressings. The donor sites and external fixator pin wounds healed well, with no functional morbidity. The cross-leg extended distally based sural artery flap is a reliable reconstructive option in challenging scenarios. Adequate flap delay, manoeuvres to reduce congestion, and postoperative rigid immobilization are key to a successful outcome.

Lower extremity flap coverage following trauma

Lower extremity injuries requiring soft tissue coverage comprises a significant proportion of these injuries worldwide. Reconstruction of the soft tissues overlying fractures is essential for bone union and reduction of infection thus improving function and reducing the rate of limb amputation. A systematic exploration and excision of the wound should be jointly performed by senior surgeons from Orthopaedic and Plastic Surgery. The grading of the injury and subsequent reconstruction of bone and soft tissue should only be planned once a thorough excision of all necrotic tissue has been performed. It is this thorough debridement and early flap coverage that contributes to infection-free bony union. This article explores the options for soft tissue flap coverage for the different zones in the lower limb.

A Modified Technique to Improve Reliability of Distally Based Sural Fasciocutaneous Flap for Reconstruction of Soft Tissue Defects Longitudinal in Distal Pretibial Region or Transverse in Heel and Ankle

Partial flap loss is a common complication of the distally based sural fasciocutaneous flap. We present a modified technique of a sloped skin island design to improve the reliability of the flap when used to reconstruct a longitudinal distal pretibial defect or transverse heel and ankle defect. Thirty-one flaps with the slope-designed skin island were used to reconstruct such defects in 30 patients. In the modified technique, the skin island was rotated toward the vascular axis of the flap. The defects were located in the distal pretibial region in 7 cases and the ankle and heel region in 24. The horizontal dimension of the skin island decreased by an average of 5.6 (range 2.5 to 14.8) cm with the sloped design, and the rotation angle varied from 42° to 90° (mean 69°). Of the 31 flaps, 29 survived, 1 developed marginal necrosis, and 1 developed lateral partial necrosis. The sloped design of the skin island is applicable to reconstruction of longitudinal distal pretibial or transverse heel and ankle defects. The modified technique can decrease the horizontal dimension and increase perfusion of the skin island, thus improving the reliability of the flap.

Reverse Sural Artery Island Flap With Skin Extension Along the Pedicle

The distally based sural flap is an efficient flap for reconstruction of soft tissues defects of lower limb. The unstable vascular pedicle, however, is prone to compression by the subcutaneous tunnel, especially when a long pedicle covers the distal area of the foot. The aim of the present study was to introduce a modified surgical technique that leaves the skin extension over the pedicle and to report the clinical results of this modification. A total of 25 consecutive patients with a mean age of 51.7 ± 14.7 years underwent surgery. We modified the conventional sural flap technique by leaving a skin extension over the entire length of the pedicle, creating a fasciocutaneous vascular pedicle. The postoperative flap survival rates, complications, and the characteristics of the flaps such as flap size, pedicle length, and the most distal area that could be covered with this modification, were reviewed. At the last clinical follow-up examination, all the flaps survived, although partial necrosis was observed in 2 (8%) cases. Four cases of venous congestion developed but healed without additional complications. The mean flap size was 5.9 ± 1.8 × 9.2 ± 2.7 cm. With this modification, the sural flap could cover the defect located in extreme distal areas, such as the medial forefoot and dorsum of the first metatarsophalangeal joint, with a longer pedicle (≤27 cm) in 7 patients (28%). A skin extension along the pedicle achieved the favorable survival rate of the sural flap and successfully extended the surgical indications to more distal areas.

The Reverse Superficial Sural Artery Flap Revisited for Complex Lower Extremity and Foot Reconstruction

Background:

Soft-tissue defects of the distal lower extremity and foot present significant challenges to the reconstructive surgeon. The reverse superficial sural artery flap (RSSAF) is a popular option for many of these difficult wounds. Our initial experience with this flap at multiple institutions resulted in a 50% failure rate, mostly because of critical venous congestion. To overcome this, we have modified our operative technique, which has produced a more reliable flap.

Methods:

All patients reconstructed with an RSSAF between May 2002 and September 2013 were retrospectively reviewed. In response to a high rate of venous congestion in an early group of patients, we adopted a uniform change in operative technique for a late group of patients. A key modification was an increase in pedicle width to at least 4 cm. Outcomes of interest included postoperative complications and limb salvage rate.

Results:

Twenty-seven patients were reconstructed with an RSSAF (n = 12 for early group, n = 15 for late group). Salvage rate in the early group was 50% compared with 93% in the late group (P = 0.02). Postoperative complications (75% vs. 67%, P = 0.70) were similar between groups. Venous congestion that required leech therapy was 42% in the early group (n = 5) and 0% in the late group (P = 0.01).

Conclusions:

Venous congestion greatly impairs the survival of the RSSAF. A pedicle width of at least 4 cm is recommended to maintain venous drainage and preserve flap viability.

Reverse sural flap with bifocal Ilizarov technique for tibial osteomyelitis with bone and soft tissue defects

Tibial osteomyelitis, in association with bone loss and a soft tissue defect, poses a significant reconstructive challenge, especially in high-risk patients. We describe a case of methicillin-resistant Staphylococcus aureus tibial osteomyelitis with intercalary bone loss successfully managed with bifocal Ilizarov compression osteogenesis at the bone resection site and proximal distraction osteogenesis, accompanied by a reverse sural fasciocutaneous flap performed with a delayed technique. When free tissue transfer is not a reconstructive option owing to medical comorbidities or patient refusal, the reverse sural flap combined with bifocal Ilizarov compression and distraction osteogenesis can provide a reconstructive option to achieve limb salvage for these challenging cases.

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.

Clinical and anatomical study of the distally based lesser saphenous veno-lateral sural neurocutaneous flap for lower extremity coverage

BACKGROUND

The distally based sural flap has been widely and successfully used to reconstruct soft tissue defects of the distal third of the lower leg and foot. Sensory loss and venous congestion are possible complications of this treatment, but there has been limited research focused on improving the sensory loss and veneous congestion. This study aimed to determine the spatial relationship between the lesser saphenous vein and the cutaneous nerves, the venous anatomy in the lower leg, and the nerve distribution in the lateral dorsum of the foot, and we presented our clinical experience.

MATERIALS AND METHODS

Twenty freshly amputated lower limbs were dissected in the 2 h following amputation. The lesser saphenous vein, medial/lateral sural nerve, and sural nerve were identified. Based on the anatomical studies, an island flap supplied by the vascular axis of the lesser saphenous vein and the lateral sural nerve was designed for clinical reparative applications in 24 cases.

RESULTS

We indicated the spatial relationship between the lesser saphenous vein and the cutaneous nerves and the venous anatomy in the lower leg. Among 24 flaps, 21 showed complete survival (87.5%), while marginal flap necrosis occurred in two patients (8.33%) and distal wound dehiscence in another (4.17%). No symptomatic neuromas were observed. Their appearance and functioning were satisfactory, with filling maintained in the heel and lateral side of the foot.

CONCLUSION

The distally based lesser saphenous veno-lateral sural neurocutaneous flap provides effective coverage of variable-sized soft tissue defects on the lower third of the lower leg and foot, without sensory loss and venous congestion.

[Transtibial amputation salvage with a cutaneous flap based on posterior tibial perforators]

When performing an amputation of the lower limb, the preservation of the knee joint is important to obtain an optimal functional outcome. Many reconstruction procedures are available to cover the amputation defect in order to preserve a sufficient length of the stump, so a prosthesis could be put in place with the best functional results. Local musculocutaneous flaps or free flaps are conventionally described with their advantages and disadvantages. In this report, we describe our experience with a transtibial amputation and stump covering using a fasciocutaneous flap based on tibial posterior perforators. An extensive tibial bone exposure with only posterior skin was viable. It is an efficient and reliable solution for covering tibial stump without microvascular anastomosis.

Increasing versatility of the distally based sural flap

Repairing distal lower limb soft tissue defects remains challenging for reconstructive surgeons. Relatively few procedures have real efficiency and low morbidity. Since its initial description, the distally based sural flap has been used increasingly for this indication. However, controversy exists about the upper limit of the skin paddle of the sural flap. In the present series, 11 patients underwent surgery with distally based sural flaps. In 6 patients, the flap skin paddle was partially or totally placed beyond this controversial limit on the proximal calf region. To increase the skin irrigation of this region, whole mesenteric tissue under the deep fascia of the leg was included in the flap. Venous congestion and distal tip necrosis can impair the success of flap surgery. To overcome these problems, the flap pedicle was not passed through the subcutaneous tunnel. All flaps survived completely, and no cases of venous congestion developed. Thus, extending the donor area to the upper part of the leg is a reliable maneuver to repair more distal defects of the leg and foot, and abstaining from passing the pedicle through a subcutaneous tunnel could contribute to a decreased risk of venous congestion.

The versatility of perforator-based propeller flap for reconstruction of distal leg and ankle defects

Introduction. Soft tissue coverage of distal leg and ankle region represents a challenge and such defect usually requires a free flap. However, this may lead to considerable donor site morbidity, is time consuming, and needs facility of microsurgery. With the introduction of perforator flap, management of small- and medium-size defects of distal leg and ankle region is convenient, less time consuming, and with minimal donor site morbidity. When local perforator flap is designed as propeller and rotated to 180 degree, donor site is closed primarily and increases reach of flap, thus increasing versatility. Material and Methods. From June 2008 to May 2011, 20 patients were treated with perforator-based propeller flap for distal leg and ankle defects. Flap was based on single perforator of posterior tibial and peroneal artery rotated to 180 degrees. Defect size was from 4 cm × 3.5 cm to 7 cm × 5 cm. Results. One patient developed partial flap necrosis, which was managed with skin grafting. Two patients developed venous congestion, which subsided spontaneously without complications. Small wound dehiscence was present in one patient. Donor site was closed primarily in all patients. Rest of the flaps survived well with good aesthetic results. Conclusion. The perforator-based propeller flap for distal leg and ankle defects is a good option. This flap design is safe and reliable in achieving goals of reconstruction. The technique is convenient, less time consuming, and with minimal donor site morbidity. It provides aesthetically good result.