Algorithm for recipient vessel selection in free tissue transfer to the lower extremity

Blunt Trauma Induced Closed Femoral Bone Fracture in a Rat Model: Are Vessels Safe to Use for Microsurgery? Further Insight into the Zone of Injury Concept

BACKGROUND

 The study aims to investigate the zone of injury for major vessels after high-velocity traumas, as it is unclear whether avoiding vascular structures is necessary during microvascular anastomosis or how long it takes for them to be used again.

METHODS

 This study uses Doppler ultrasonography and a rat model to evaluate the histopathological changes and flow velocity of major vessels in the zone of injury after high-velocity trauma with closed femoral bone fracture. Osteosynthesis was performed using an intramedullary wire. Samples were collected from day 3 and week 3. The unaffected contralateral side is used as control.

RESULTS

 Results from arterial and venous flow assessments showed no evidence of ischemia in the extremities. Both arteries and veins were patent in both intervals and on the control side. The evaluation of the vessels showed arterial injury with a slightly reduced arterial flow on day 3 and week 3. The venous flow was slightly reduced on day 3 but not on week 3. Statistically, arterial endothelial injury was higher on day 3 than on week 3 (p = 0.006). Media inflammation was also higher on day 3 (p = 0.06). Arterial endothelization distribution was higher in week 3 (p = 0.006). No significant differences were found in arterial media irregularity, necrosis, platelet aggregation, bleeding, and wall rupture. Venous samples showed no significant differences in any parameter (p < 0.05).

CONCLUSION

 High-velocity trauma increases the risk of thrombosis in vessels. Intravascular repair can start on day 2 and continue till week 3 with significant endothelization. Although physiologic findings do not alter arterial or venous flow, histologic findings support vessel injuries leading to potential complications. Microsurgery should be considered out of the injury zone until adequate vessel healing is achieved.

Soft Tissue Reconstruction After Revascularization

Diabetic foot ulcer represents the primary cause of hospital admissions, amputations, and mortality in diabetic patients. The development of diabetic foot ulcers is influenced by peripheral neuropathy, infection, and ischemia, with diabetes contributing to peripheral artery disease. Free tissue transfer combined with revascularisation of the lower extremity provides the potential opportunity for limb salvage in individuals with lower extremity defects due to critical limb ischemia and diabetic foot.

[Treatment strategies for fracture-related infections with concurrent soft tissue damage]

Fracture-related infections are the predominant complication following surgical fracture treatment. The distal lower leg, e.g., in pilon tibial fractures, is at a high risk of infection due to poor soft tissue coverage, particularly in cases of open fractures in this area. Fracture-related infections with significant soft tissue damage require special attention alongside treatment of the infection itself. In general, the principle is that healing of fracture-related infection is not possible without sufficient soft tissue coverage. Therefore, it is crucial to integrate both soft tissue damage and fracture-related infection into a comprehensive treatment plan from the beginning. An interdiscpilinary treatment approach between trauma and plastic surgery is often necessary and beneficial. In cases, where fracture fixation devices or bone is exposed, mid- or long-term use of vacuum-assisted wound therapy is not advisable due to a higher risk of reinfection. Hence, an interdisciplinary treatment strategy involving trauma and plastic surgery should prioritize early soft tissue closure, referred to as the "orthoplastic approach". If this cannot be done in the own hospital, early patient transfer is indicated to ensure optimal interdisciplinary therapy with early soft tissue closure and simultaneous trauma surgical treatment to control the infection and enable bone healing. Free fasciocutaneous or muscle flap techniques in combination with adequate trauma surgical and antibiotic therapy lead to good reliable results in these situations.

A simple free flap strategy using end-to-side anastomosis to the main vessels in injured extremity

Background

During free flap surgery, the surgeon sometimes encounters problems with anastomosis such as intractable arterial spasms or vessel size discrepancy in venous anastomoses. End-to-side (ETS) anastomosis has the advantages of limited chance of vessel spasm and easy handling by adjusting for vessel size discrepancy. We introduced the arterial and venous end-to-side anastomosis (AV-ETS) strategy, which is based on the ETS anastomosis to the main artery and accompanying veins, to avoid intraoperative anastomotic problems when creating a free flap. The aim of this study was to compare flap outcomes and intraoperative anastomotic problems before and after introduction of the AV-ETS strategy in extremity free flap surgery.

Materials and methods

We retrospectively examined 72 consecutive extremity free flaps. Before introducing the AV-ETS strategy, we used the conventional strategy in which the recipient artery was selected according to the number of the remaining main artery and the anastomosis technique was flexibly changed, although the end-to-end (ETE) technique was used in most cases.

Results

The conventional group had 18 flaps and the AV-ETS group had 54 flaps. The rate of flap survival did not differ between these groups, and there were no cases of flap failure after the introduction of the AV-ETS strategy. The AV-ETS group had significantly fewer flaps that required a change in preoperative planning for the recipient artery or anastomotic site of the artery.

Conclusions

The AV-ETS strategy may facilitate reliable preoperative planning and the performance of stable free flap surgery without requiring a flexible response during surgery.

Use of Recanalized Vessels for Diabetic Foot Reconstruction: Pushing the Boundaries of Reconstruction in a Vasculopathic Lower Extremity

BACKGROUND

Free flap after lower extremity revascularization may enable limb salvage in defects after critical limb ischemia. This study examined the outcomes of reconstruction of ischemic diabetic foot according to the severity of the vessel occlusion and assessed whether recanalized vessels may serve as a reliable recipient vessel.

METHODS

A total of 62 patients who underwent diabetic foot reconstruction with free flaps after successful percutaneous transluminal angioplasty (PTA) from February of 2010 to February of 2016 were identified and divided into three groups: group 1, nonoccluded vessels as recipient ( n = 11); group 2, recanalized artery after PTA for partially occluded artery ( n = 30); and group 3, recanalized artery after PTA for completely occluded artery ( n = 21).

RESULTS

Flap survival was statistically higher in group 2 (90%) compared with group 3 (67%) ( P < 0.05). Subsequent major amputation was significantly lower in groups 1 and 2 [0/7 and 1/30 (3.3%)] compared with group 3 [5/21 (23.8%)] ( P < 0.05). The patient survival and limb salvage rate was 90.9% at 1 and 3 years in group 1, 89.8% at 1 year and 86.3% at 3 and 5 years in group 2, and 76.2% at 1, 3, and 5 years in group 3. This difference was not statistically significant ( P = 0.485).

CONCLUSIONS

The use of recanalized vessels after PTA can be safe for partially occluded arteries but requires caution for completely occluded arteries. Using completely occluded vessels after PTA can be attempted when other options are not available and achieves a 76% chance of limb salvage.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Sural Artery as a Recipient Vessel for Free Flaps

Introduction The axial vessels like the anterior and posterior tibial emerge as the first choice of recipient vessels, in free flaps for lower limb trauma. When the defects are located more proximally in the leg, the deeper course of the axial vessels makes the dissection more tedious. Alternative vessels like the descending genicular, medial genicular, and distal end of the descending branch of the lateral circumflex femoral can be used for an end-to-end anastomosis, well away from the zone of trauma.

The objective of this study was to define the indications and technique of the use of the sural vessels as the recipient pedicle for proximal and middle third leg defects.

Patients and Methods For the period 2006 to 2022, 18 leg defects following road traffic accidents were covered with latissimus dorsi muscle flap using sural vessels as the recipient pedicle.

Results Among 18 patients, 8 patients had defect in proximal third, 8 had a combined defect in proximal and middle third leg, and 2 had defect in middle third leg. Two patients developed arterial thrombosis and one patient had venous thrombosis for which re-exploration was performed. Two flaps were lost and sixteen had successful wound coverage.

Conclusion The sural vessels as recipient pedicle are easier to access and can be considered as a reliable option for free flaps in limb defects of proximal and middle third leg. Using the submuscular part of the vessel ensures a better distal reach of the flap.

The Great Saphenous Vein-An Underrated Recipient Vein in Free Flap Plasty for Lower Extremity Reconstruction: A Retrospective Monocenter Study

Background  Reconstruction of large soft tissue defects of the lower extremity often requires the use of free flaps. The main limiting factor and potential for complications lie in the selection of proper donor and recipient vessels for microvascular anastomosis. While the superficial veins of the lower leg are easier to dissect, they are thought to be more vulnerable to trauma and lead to a higher complication rate when using them instead of the deep accompanying veins as recipient vessels. No clear evidence exists that proves this concept.

Methods  We retrospectively studied the outcomes of 97 patients who underwent free flap plasty to reconstruct predominantly traumatic defects of the lower extremity at our institute. The most used flap was the gracilis muscle flap. We divided the population into three groups based on the recipient veins that were used for microvascular anastomosis and compared their outcomes. The primary outcome was the major complication rate.

Results  Overall flap survivability was 93.81%. The complication rates were not higher when using the great saphenous vein as a recipient vessel when comparing to utilizing the deep concomitant veins alone or the great saphenous vein in combination to the concomitant veins.

Conclusions  In free flap surgery of the lower extremity, the selection of the recipient veins should not be restricted to the deep accompanying veins of the main vessels. The superficial veins, especially the great saphenous vein, offer an underrated option when performing free flap reconstruction.

Primary Use of the Deep Inferior Epigastric Pedicle for Free-flap Phalloplasty: Rationale, Technique, and Outcomes

Most free-flap phalloplasty reports describe the femoral artery and great saphenous vein as recipient vessels, with the deep inferior epigastric artery and venae comitantes (DIEA/V) only rarely reported. We review our experience with preferentially using the DIEA/V as recipient vessels in gender-affirming free-flap phalloplasty, with DIEV as primary venous outflow.

Microsurgical anastomosis using anterior versus posterior tibial artery in lower limb free tissue transfer

BACKGROUND

Soft tissue lower limb reconstruction often requires free tissue transfer. We investigated whether the target vessels used for micro-vascular anastomosis in the lower limb influences microsurgical outcomes.

METHODS

Data from Plastic Surgery Departments of a major tertiary hospital in the United Kingdom (Leeds General Infirmary, LGI) and Australia (Princess Alexandra Hospital, PAH) were retrospectively analysed. Patients who underwent lower limb free flap reconstruction using the posterior (PTA) or anterior tibial artery (ATA) were included. Patient demographics, free flap and microvascular anastomosis details were analysed. Primary outcome was flap failure. Secondary outcome was return to theatre.

RESULTS

Two hundred and thirty-four free flaps were included (PAH 115; LGI 119). 60% were muscle flaps. Eighty-one percent of patients were male, with trauma the cause in 82%. PTA was used for microsurgical anastomosis in 70% of cases. Venae comitantes were preferred (96%) for venous anastomosis. PTA group showed a higher proportion of patients with trauma as the mechanism of injury. ATA group was more likely to have an end-to-end arterial anastomosis configuration. Total flap loss was 3.8%. There was no clinically significant difference in flap failure or return to theatre using ATA versus PTA.

CONCLUSIONS

Incidence of lower limb free flap failure is low (<5%) and not influenced by use of ATA versus PTA for microsurgical anastomosis. The choice of target vessels for microsurgical reconstruction of the lower limb should be predicated upon factors other than aversion to one or another vessel. If all other microsurgical considerations are equal, the surgeon can exercise personal preference.

Using Duplex Ultrasound for Recipient Vessel Selection

INTRODUCTION

 Among the many factors involved in reconstructive microsurgery, identifying a good recipient vessel is one of the key elements leading to a successful result.

MATERIAL AND METHOD

 Multiple modalities have been used to identify recipient vessels from simple palpation of axial arteries to hand-held Doppler, duplex ultrasound, computed tomography angiograms, and other advanced techniques. Although these various modalities bring their own unique advantages, using the duplex ultrasound can provide far superior and real-time information based on the anatomy and physiology of the recipient vessel.

RESULT

 Duplex ultrasound is a valuable and powerful tool for reconstructive surgeons who are interested in performing microsurgery or supermicrosurgery.

CONCLUSION

 As we enter the era of individualized/customized reconstruction using superthin flaps, perforator-to-perforator anastomosis, and supermicrosurgery, understanding and becoming versatile with duplex ultrasound will be critical especially in choosing recipient vessels.

Are Perforators Reliable as Recipient Arteries in Lower Extremity Reconstruction? Analysis of 423 Free Perforator Flaps

BACKGROUND

Perforator flaps have revolutionized lower limb reconstruction by offering single-stage thin, pliable coverage with an excellent aesthetic match. Although anastomosis of the flap to a major artery remains the gold standard, perforator-to-perforator anastomosis has several advantages, including expedient recipient dissection and increased recipient options in vessel-depleted extremities. The aim of this study was to compare flap survival when a perforator or major artery was used as a recipient vessel.

METHODS

A retrospective cohort of free perforator flaps for lower limb reconstruction was reviewed. Demographics, comorbidities, vascular status, defect characteristics, operative details, and complications were recorded. Outcomes for perforator and major artery recipients were compared.

RESULTS

Four hundred twenty-three flaps were performed for various reasons using perforator flaps. The total limb salvage rate was 98.8 percent. Total and partial flap failure rates were 6.1 percent and 9.0 percent, respectively. Comparing perforator recipients [n = 109 (25.8 percent)] to major artery recipients [n = 314 (74.2 percent)], there was no significant difference in total (p = 0.746) or partial flap failure (p = 0.212). Significant factors between the groups included larger flap size with major artery recipients (p = 0.001) and shorter operative time when using a perforator recipient (p = 0.012).

CONCLUSIONS

Perforator-to-perforator anastomosis is a reliable option that affords equivalent rates of flap success compared to major artery anastomosis in lower extremity reconstruction. The authors advocate using a major artery recipient in defects where the axial vessels are easily accessible. A perforator recipient is a viable alternative in defects where access to the axial vessels is inconvenient and in patients with limited recipient options.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Overcoming severe calcified lower extremity artery in lower limb salvage operation by using the Fogarty catheter and vein graft

BACKGROUND

With severe vascular calcifications, vascular clamp application and utilizing the vessel for free flap recipient vessel becomes impossible. These obstacles can be overcome with the Fogarty catheter and vein graft.

PATIENTS AND METHODS

When unclampable artery was encountered intraoperatively, a vein graft was used to make a clampable recipient site for six diabetic foot patients (ages from 42 to 80). The end of the Fogarty catheter was inserted into the proximal end of the vein graft and the transected calcified vessel in sequence, and the balloon of the catheter was used as an intraluminal tourniquet. The remaining end of the vein graft was connected to the distal vessel with a vascular clamp.

RESULTS

Five short vein graft revascularization for segmental arterial occlusion, one long vein graft for recipient artery elongation was done (lengths from 2 to 13.8 cm). Three delayed, and two immediate anterolateral thigh flaps (sizes from 15 to 150 cm² ) were performed, and one patient received vein graft revascularization surgery only. Postoperative vascular sonography of all six patients showed well-maintained patency. Minor flap marginal disruption occurred at two patients but healed with conservative care. Postoperative follow-up was done for 1-18 months (average 7.17). Limb salvage was achieved for five patients and all five free flaps survived. However, for one patient, arterial restenosis at popliteal artery a month later lead to major amputation.

CONCLUSION

Using a Fogarty catheter and a vein graft may obtain perfect hemostasis during micro-anastomosis and achieve successful microvascular reconstruction in patients with severely calcified vessels.

Advancements in Reconstructive Surgery Broaden Opportunities for Salvage of the Injured Lower Extremity

Advancements in microsurgery have made lower extremity reconstruction possible even after major soft tissue loss or tibial nerve disruption. There is an ongoing paradigm shift in the indications for amputation versus salvage and in flap selection protocols for different areas of the lower extremity. Initial evaluation, patient selection, triage, and timing of reconstruction are essential factors that can influence functional and aesthetic outcomes. The emergence of perforator flaps and the application of new concepts such as free-style flaps, propeller perforator flaps, thinning of free flaps, and supermicrosurgery have provided reconstructive surgeons with many techniques to decrease donor-site morbidity and improve outcomes. This includes options for reconstruction on extremities with single or no adequate runoff vessels. We present a review of the major advancements in reconstructive surgery for salvage of the traumatic lower extremity.

Use of a biopsy punch for end-to-side anastomosis in free-tissue transfer

Background: In end-to-side vessel-anastomoses, a side fenestration should be made by a slit incision or partial excision of the vessel wall. However, a slit incision might restrict blood flow across the anastomosis, and a partial vessel wall excision using micro-scissors may be time-consuming and result in irregular edges, which may weaken the vessel wall and cause flow disturbances. We used a biopsy punch for end-to-side anastomosis, and obtained satisfactory results.Methods: Between September 2015 and August 2017, 27 end-to-side anastomoses using punch biopsies were performed. Two vessel clamps were applied to the recipient vessel proximal and distal to the point planned for the side anastomosis. The flap side vessel size was measured, and an appropriately sized punch was selected. The clamped recipient vessel was supported by a wooden tongue depressor and the punch was applied to the vessel wall. An end-to-side anastomosis was performed in the usual manner, and immediate patency was tested with a refill test.Results: The vessel patency rate was 96 percent. The mean arteriotomy or venotomy time was 65 s and entire anastomosis procedure time was 1065 s. Both the vessel preparation and the micro-anastomosis procedure times were shorter than those of the conventional procedure group with statistical significance. (p < .05) There was only one case of venous failure by deep vein thrombosis - and it was resolved with thrombectomy and re-anastomosis.Conclusion: Use of a biopsy punch in end-to-side anastomosis can offer a uniform circular edge and reduce operating time.

Importance of Vascularity and Selecting the Recipient Vessels of Lower Extremity Reconstruction

BACKGROUND

 Successful lower extremity reconstruction using free flaps begins by identifying a good recipient vessel and understanding the surrounding environment of the defect.

METHODS

 One should consider multiple factors when selecting the recipient vessel such as the status of the axial arteries, trying to preserve flow as much as possible, extent and severity of the defect, and ultimately what type of anastomosis will be ideal.

RESULTS

 Multiple factors of importance are reviewed and show the relevance in decision making and provide an algorithm.

CONCLUSION

 In addition to the multiple factors to be considered, the ultimate decision should be made on the table during surgery when the actual artery or vein is exposed and shows signs of good pulsation and flow.

Selecting a free flap for soft tissue coverage in lower extremity reconstruction

BACKGROUND

Goals of lower extremity microvascular reconstruction (LEMR) include the restoration of function, prevention of infection, and optimal cosmesis. Indications for LEMR include large defects that are not amenable to pedicled options, a large zone of injury, and large complex defects. The novice microsurgeon should first master a handful of free flaps to develop an armamentarium of options for addressing such defects. The scope of this review is to provide free flap options for LEMR in any of the thirds of the lower leg. After reading this article, the reader will understand variations, advantages, disadvantages, indications, and tips for raising each of these flaps.

METHODS

Six most commonly used free flaps for LEMR are described in this paper, including the anterolateral thigh flap (ALT) and its variations, the radial forearm flap (RFFF), the lateral arm flap (LAF), the gracilis muscle flap, the rectus abdominis flap (RAF) and the latissimus dorsi flap and its variations. Indications, advantages, disadvantages and technique tips are discussed for each flap. Moreover, selection of the recipient vessels, preoperative management along with an algorithm are also provided.

CONCLUSIONS

The ALT flap is a workhorse in covering defects of the leg, foot, and ankle. It's the flap of choice at our institution, especially given the number of traumatic wounds seen as a result of motor vehicles, all-terrain vehicles (ATV), lawnmowers, and gunshot wounds (GSW). At times, the lower extremity zone of injury requires a distant donor site. The RAF can also provide coverage for large soft tissue defects but donor-site morbidity remains its main drawback. The LAF and RFFF provide two pliable options, one that provides pliable soft tissue with minimal donor site morbidity and another that provides a long pedicle. The free gracilis flap is an excellent choice for crossing the ankle joint. Lastly, the free latissimus dorsi is indicated for large defects of the lower extremity independently of the location.

A retrospective analysis of latissimus dorsi-serratus anterior chimeric flap reconstruction in 47 patients with extensive lower extremity trauma

Background:

Many flaps have been described for reconstruction of lower extremity defects, including, Latissimus Dorsi, Rectus abdominis, Anterolateral thigh perforator flaps, each having advantages and disadvantages. The defect location, size and specific geometric pattern of defect influences the type of flap that can be used. In this case series, we describe the specific situations where the use of chimeric latissimus dorsi–serratus anterior (LD + SA) free flaps are of advantage in providing complete wound cover.

Materials and Methods:

Case records of all patients who underwent LD + SA free flap transfer for lower extremity trauma at Amandeep Hospital, from Feb 2006 to Feb 2017 were reviewed. Patients were categorised based on the anatomical location and size of defect. The method of usage of the chimeric segments, recipient vessels and type of anastomosis were noted. Flap complications, if any were reviewed.

Result:

47 patients with lower limb defects were included in the study. All cases were post traumatic in nature. Defect size ranged from 180 sq cm to 1050 sq cm. Average defect size was 487.70 sq cm. All patients underwent soft tissue reconstruction with LD + SA flap. Complete wound cover was obtained.

Conclusion:

Latissimus dorsi + Serratus anterior free tissue transfer is an effective, reliable method of providing cover to extensive lower limb traumatic defects with minimal donor site morbidity, with added freedom of inset and flap positioning. Specific use is seen in patients with broad proximal defect, long defect in the leg, defects involving adjacent anatomical areas and in large defect with dead space.

Review of Cross-Leg Flaps in Reconstruction of Posttraumatic Lower Extremity Wounds in a Microsurgical Unit

Since the advent of microsurgery, and expanding expertise in the field, extensive traumatic wounds of leg have been managed successfully with free tissue transfer. Various patient-related factors may preclude the use of free flaps even in units with available expertise and infrastructure. It is in such situations that the "cross-leg flap" comes into play. In these cases, instead of attempting complicated anastomotic techniques or anastomosis in the zone of trauma, it is better to perform the simpler and more reliable cross-leg flap. In this study, we try to show the utility of a cross-leg flap based on a retrospective study of 198 patients who underwent cross-leg flap in our institute over a period of 15 years extending from November 2003 to March 2018.

MATERIALS AND METHODS

Case sheets of all patients who underwent cross-leg flap from November 2003 to March 2018 were reviewed. The location of defect in the leg, the indication for cross-leg flap, the pattern of cross-leg flap, and perioperative complications were noted.

RESULTS

A total of 198 patients underwent cross-leg flap for traumatic soft tissue injury of leg during this period. The most common reason for performing cross-leg flap was poor pulsatility of the recipient artery as seen intraoperatively, followed by the economics of the procedure wherein the initial cost of free flap was found significantly higher compared with cross-leg flap. All flaps survived with partial necrosis occurring in 23 patients. All flaps settled well by 2 years' time. Bony union/fracture healing evaluation was not a part of this study.

CONCLUSION

Cross-leg flap is still a useful tool for leg wound coverage even in microsurgical unit in situations precluding free flap coverage.

Medial approach to the peroneal vessels as recipients for free flap reconstruction of the leg

The anatomic variation in the branching pattern of the popliteal vessel has been well-established. Little has been written in the literature regarding recipient vessel selection for microvascular reconstruction in the lower extremity as it pertains to aberrant vascular anatomy. We present the case of a 57-year-old male patient who sustained a closed right lower extremity pilon fracture in a motor vehicle accident. The patient was initially treated with external fixation, which was followed by definitive open reduction and internal fixation 3 weeks later. Over the next 2 weeks, the patient developed skin ischemia of the anterior ankle. A free-tissue transfer was planned. A digital subtraction angiogram revealed absence of the posterior tibial (PT) vessels and an aberrant course of the peroneal (PR) artery. In the operating room, the medial distal leg was explored for the PT vessels, which were severely hypoplastic. Given the close proximity of the PR vessels, the dissection was extended proximally to assess these vessels for microvascular anastomosis. They were found to be suitable. A parascapular flap was harvested and transferred to the right leg wound without any significant stretch on the vessels for soft tissue coverage. The flap demonstrated excellent inflow and outflow, and the leg and foot remained well perfused. The patient's postoperative course was uncomplicated. The technique of exposing the peroneal vessels for microvascular anastomosis via a medial approach is described. This technique is an excellent option to have available when aberrant anatomy precludes the use more commonly utilized vessels.

[Free flaps use in chronic wounds: Retrospective study about 91 cases]

INTRODUCTION

Chronic wounds represent a major health challenge with no current standardized surgical treatment. The use of free flaps is little discussed in the literature, with a supposed propensity to failure given unfavorable local conditions and land often debility. We present here the analysis of our monocentric experience of the use of free flaps in the curative treatment of chronic wounds.

PATIENTS ET METHODS

We performed a retrospective monocentric study over 18 years of all free flaps used for the treatment of a chronic wound between January 2001 and September 2016. Several criteria were evaluated on patients, wounds, free flaps used and immediate to late outcomes.

RESULTS

Ninety-one patients were included (sex ratio M/F: 3.55) with an average age of 41.6±16 years. Wounds were localized to the leg in 92.3% of cases and 58% of patients had initial osteomyelitis. The flaps used were predominantly muscle flaps (61.6%). The flaps survival rate was 92.3%. With a mean follow-up of 50 months, the reconstructive failure rate was 20.9%. The presence of a chronic osteomyelitis is the only statistically significant factor of reconstruction failure (P=0.0169) with a risk of failure multiplied by 5.

CONCLUSION

Our study demonstrates that the reliability of free flaps in the treatment of chronic wounds is comparable, regardless of the time since the initial cutaneous lesion, to that existing in the treatment of acute wounds or in the reconstruction after oncological excision. The presence of a chronic osteomyelitis, however, represents a major risk of reconstruction failure by increasing 5 times the risk of failure. Recent changes in the integumentary reconstruction paradigm of the lower limb will undoubtedly allow in the next few years to establish more rationally the place of muscle free flaps in the therapeutic armamentarium of chronic wounds.

Patient Height, Weight, BMI and Age as Predictors of Gracilis Muscle Free-Flap Mass in Lower Extremity Reconstruction

BACKGROUND

Gracilis muscle flap is commonly used for the reconstruction of defects of the lower extremities. Preoperative evaluation of gracilis muscle dimension is a key aspect in surgical planning. This study aimed to determine whether patient height, weight, body mass index (BMI) and age are reliable proxy measurements of the mass of gracilis muscle flap.

PATIENTS AND METHODS

Twenty-two patients treated for lower extremity reconstruction with free gracilis flap between December 2010 and December 2014 were considered. The relationships between the mass of gracilis muscle and patient height, weight, BMI and age were assessed with Pearson's product moment correlation coefficient. Defect size, mass of gracilis muscle resected and surgical outcomes were also evaluated.

RESULTS

There was a moderate correlation between the mass of the gracilis muscle and patient height (r=0.4), weight (r=0.4), and BMI (r=0.3), and moderate inverse correlation with age (r=-0.04). Lower extremities defects ranged in size from 3×4 cm (12 cm²) to 26×11 cm (286 cm²) with a mean of 81.6 cm² All defects were reconstructed with the gracilis muscle, which required a resection ranging between 3 g and 105 g (mean=37.4 g) to adapt the flap to the recipient site. Complete flap loss was observed in one case.

CONCLUSION

In our series, the mass of the gracilis muscle flap was predictable in relation to height, weight, BMI, and age, which can be considered reliable proxy measurements. This will contribute to adequate flap selection for microsurgical reconstruction of lower extremity defects.

Validity of the use of a subfascial vessel as the recipient vessel in a second free flap transfer: A retrospective clinical review

Performing a greater number of free flap procedures inevitably results in an increase in the number of cases that experience free flap failure. In cases that require a second free flap after the failure of the first, recipient vessel selection becomes difficult. Furthermore, recipient vessel selection can be complicated if the vessel is deep in the recipient site, or if there is an increased risk of vessel damage during the dissection. Thus, we present our experience where a subfascial vessel beneath the deep fascia was used as a recipient vessel for a second free flap in lower extremity reconstruction due to total or partial first flap failure.Between January 2010 and April 2015, 5 patients underwent second free flap reconstruction using a subfascial vessel as the recipient vessel. The flaps were anastomosed in a perforator-to-perforator manner, using the supermicrosurgery technique. We measured the sizes of the flaps, which varied from 5 × 3 to 15 × 8 cm, and the recipient subfascial vessel diameters.The mean time for the dissection of the recipient perforator was 45 minutes. All the flaps exhibited full survival, although a partial loss of the skin graft at the flap donor site was observed in 1 patient; this defect healed with conservative management.We recommend using a subfascial vessel as the recipient vessel for both first and second free flaps, especially if access to the major vessel is risky or challenging.

Double free-flap for a bimalleolar defect of lower leg and ankle

Double free-flaps are necessary when tissue cover cannot be sufficed with a single flap. The other factors to be considered when using two free flaps for resurfacing of distal limb defects are the availability of more than one recipient vessel, the risk of distal limb ischaemia and the donor site morbidity of double flap harvest. If these factors are adequately addressed, double free-flaps can be safely executed for resurfacing distal limb defects with minimal morbidity. We report the simultaneous harvest and transfer of the anterolateral and anteromedial thigh flaps inset and vascularised as double free-flaps to resurface a large bimalleolar defect in a 14-year-old boy with no additional morbidity as compared to that of a single free tissue transfer.

Lateral Approach to the Popliteal Artery for Free Tissue Transfer to the Lower Extremity

Free tissue transfer to the proximal leg and knee requires appropriate recipient vessel selection. The popliteal vessels have historically been unpopular choices, due to their remote location often necessitating vein grafts, and need for prone positioning. In this report, we describe a lateral approach to the above-knee popliteal vessels, which was utilized for 2 cases of free tissue transfer to the lower extremity. Neither prone positioning nor vein grafts were needed. The lateral approach to the above-knee popliteal vessels and their branches is a viable option for the otherwise recipient vessel-depleted lower extremity.

The lower medial thigh perforator (LMTP) flap for lower extremity reconstruction: Preliminary results

BACKGROUND

The lower medial thigh perforator (LMTP) flap is an alternative source for lower extremity reconstruction. In this article, we report the preliminary results of reconstruction of the lower extremity with a series of patients by the lower medial thigh perforator flap.

PATIENTS AND METHODS

From January 2015 until August 2015, we performed six cases of lower extremity reconstruction with the LMTP flap. The defect locations included the distal leg (1 case) and the proximal leg (2 cases), the left foot (2 cases), and the right foot (1 case). The perforators of the flap design were detected at the distal third of the line, which was drawn from the midpoint of inguinal ligament to medial upper border of patella. The dorsalis pedis artery (2 cases), anterior tibia artery (2 cases), posterior tibial artery (2 cases) were dissected as recipient vessels.

RESULTS

The average size of flap was 10.5 × 5 cm (range 10-15 cm and 4-6.5 cm), and the average pedicle length was 7.6 cm (range 5-9.5 cm). 83% of the perforators (5 of 6) were musculocutaneous type, and 17% (1 of 6) were septocutaneous type. The flap survival rate was 100%; the venous congestion was observed in one flap and was successfully salvaged by performing revised venous anastomosis. The donor sites were all closed primarily with minimal morbidity. Follow-up observations were conducted for 2-6 months, and all patients had good functional recovery with satisfactory cosmetic results.

CONCLUSION

The lower medial thigh perforator flap has some advantage in lower extremity reconstruction, including adequate length and vessel diameter of pedicle for microvascular anastomosis to the lower extremities recipient vessels. The LMTP flap indicates a low donor-site morbidity and it could be a safe, reliable, and aesthetically appealing new option for lower extremity reconstruction. © 2016 Wiley Periodicals, Inc. Microsurgery 36:474-479, 2016.

What is the role of bosentan in healing of femur fractures in a rat model?

The purpose of this study was to examine the effects bosentan (which is a strong vasoconstrictor) on bone fracture pathophysiology, and investigate the roles of the nonselective endothelin 1 receptor blocker bosentan on the bone fractures formed in rats through radiographic, histopathologic, and immunohistochemical methods. The rats were divided into three groups (six rats in each group): a femoral fracture control group, a femoral fracture plus bosentan at 50 mg/kg group, and a femoral fracture plus bosentan at 100 mg/kg group. The femoral fracture model was established by transversely cutting the femur at the midsection. After manual reduction, the fractured femur was fixed with intramedullary Kirschner wires. The radiographic healing scores of the bosentan 100 and 50 mg/kg groups were significantly better that those of the fracture control group. The fracture callus percent of new bone in the bosentan 100 mg/kg group was significantly greater than that in the control group. Also, semiquantitative analysis showed higher positive vascular endothelial growth factor and osteocalcin staining and lower positive endothelin receptor type A staining in the treatment groups than in the control group. Bosentan treatment also decreased tissue endothelin 1 expression relative to that in the fracture control group. As a result of our study, the protective effect of bosentan was shown in experimental femoral fracture healing in rats by radiographic, histopathologic, and molecular analyses.

Vascular considerations in foot and ankle free tissue transfer: Analysis of 231 free flaps

OBJECTIVE

Successful foot and ankle soft tissue reconstruction is dependent on a clear understanding of the vascular supply to the foot. The aim of this study was to identify risk factors for reconstructive failure following foot and ankle free tissue transfer.

METHODS

The authors retrospectively reviewed their 17-year institutional experience with 231 foot and ankle free flaps performed in 225 patients to determine predictors of postoperative foot ischemia and flap failure. Postoperative foot ischemia was defined as ischemia resulting in tissue necrosis, separate from the reconstruction site.

RESULTS

Six (3%) patients developed postoperative foot ischemia, and 28 (12%) patients experienced flap failure. Chronic ulceration (P = 0.02) and an elevated preoperative platelet count (P = 0.04) were independent predictors of foot ischemia. The presence of diabetes was predictive of flap failure (P = 0.05). Flap failure rates were higher in the setting of an abnormal preoperative angiogram (P = 0.04), although the type and number of occluded arteries did not influence outcome. Foot ischemia was more frequent following surgical revascularization in conjunction with free tissue transfer and the use of the distal arterial bypass graft for flap anastomosis (P < 0.01). Overall, no differences were observed in foot ischemia (P = 0.17) and flap failure (P = 0.75) rates when the flap anastomosis was performed to the diseased artery noted on angiography, compared with an unobstructed native tibial artery.

CONCLUSIONS

Foot and ankle free tissue transfer may be performed with a low incidence of foot ischemia. Patients with diabetes, chronic ulceration, and an elevated preoperative platelet count are at higher risk for reconstructive failure. © 2015 Wiley Periodicals, Inc. Microsurgery 36:276-283, 2016.

Unfavourable results in free tissue transfer

With recent advances in the instrumentation and with increased expertise the results of microvascular surgery are getting better. Complications though, cannot be completely avoided. This paper gives a brief introduction to the possible complications at various stages of free tissue transfer. With careful planning and execution and vigilant postoperative care the overall success rate can be improved.

Limb salvage surgery

The threat of lower limb loss is seen commonly in severe crush injury, cancer ablation, diabetes, peripheral vascular disease and neuropathy. The primary goal of limb salvage is to restore and maintain stability and ambulation. Reconstructive strategies differ in each condition such as: Meticulous debridement and early coverage in trauma, replacing lost functional units in cancer ablation, improving vascularity in ischaemic leg and providing stable walking surface for trophic ulcer. The decision to salvage the critically injured limb is multifactorial and should be individualised along with laid down definitive indications. Early cover remains the standard of care, delayed wound coverage not necessarily affect the final outcome. Limb salvage is more cost-effective than amputations in a long run. Limb salvage is the choice of procedure over amputation in 95% of limb sarcoma without affecting the survival. Compound flaps with different tissue components, skeletal reconstruction; tendon transfer/reconstruction helps to restore function. Adjuvant radiation alters tissue characters and calls for modification in reconstructive plan. Neuropathic ulcers are wide and deep often complicated by osteomyelitis. Free flap reconstruction aids in faster healing and provides superior surface for offloading. Diabetic wounds are primarily due to neuropathy and leads to six-fold increase in ulcerations. Control of infections, aggressive debridement and vascular cover are the mainstay of management. Endovascular procedures are gaining importance and have reduced extent of surgery and increased amputation free survival period. Though the standard approach remains utilising best option in the reconstruction ladder, the recent trend shows running down the ladder of reconstruction with newer reliable local flaps and negative wound pressure therapy.

Recipient vessels in the free flap reconstruction around the knee

Microsurgical free tissue transfer is playing a critical role in reconstruction of the soft tissue around the knee to salvage the limb, especially when the defects exist with a wide zone of injury or with a poor soft tissue condition, where local flaps are unavailable. For a successful free flap transfer, proper selection of a recipient vessel is essential and challenging. The survival and other outcomes of the transferred flaps were closely related to which recipient vessel was used and the location of anastomosis. In this article, we review most of the clinical reports about using free flaps to reconstruct the soft tissue around the knee, excluding the cases of postamputation, and discuss about the recipient vessels that can be used.

VEGF and bone cell signalling: an essential vessel for communication?

Vascular endothelial growth factor (VEGF) is an endothelial cell survival factor and is required for effective coupling of angiogenesis and osteogenesis. Although central to bone homeostasis, repair and the pathobiology that affect these processes, the precise mechanisms coupling endothelial cell function within bone formation and remodelling remain unclarified. This review will (i) focus on the potential directionality of VEGF signalling in adult bone by identifying the predominant source of VEGF within the bone microenvironment, (ii) will summarize current VEGF receptor expression studies by bone cells and (iii) will provide evidence for a role for VEGF signalling during postnatal repair and osteoporosis. A means of understanding the directionality of VEGF signalling in adult bone would allow us to most effectively target angiogenic pathways in diseases characterized by changes in bone remodelling rates and enhance bone repair when compromised.

Vascular development during distraction osteogenesis proceeds by sequential intramuscular arteriogenesis followed by intraosteal angiogenesis

Vascular formation is intimately associated with bone formation during distraction osteogenesis (DO). While prior studies on this association have focused on vascular formation locally within the regenerate, we hypothesized that this vascular formation, as well as the resulting osteogenesis, relies heavily on the response of the vascular network in surrounding muscular compartments. To test this hypothesis, the spatiotemporal sequence of vascular formation was assessed in both muscular and osseous compartments in a murine model of DO and was compared to the progression of osteogenesis. Micro-computed tomography (μCT) scans were performed sequentially, before and after demineralization, on specimens containing contrast-enhanced vascular casts. Image registration and subtraction procedures were developed to examine the co-related, spatiotemporal patterns of vascular and osseous tissue formation. Immunohistochemistry was used to assess the contributory roles of arteriogenesis (formation of large vessels) and angiogenesis (formation of small vessels) to overall vessel formation. Mean vessel thickness showed an increasing trend during the period of active distraction (p=0.068), whereas vessel volume showed maximal increases during the consolidation period (p=0.009). The volume of mineralized tissue in the regenerate increased over time (p<0.039), was correlated with vessel volume (r=0.59; p=0.025), and occurred primarily during consolidation. Immunohistological data suggested that: 1) the period of active distraction was characterized primarily by arteriogenesis in the surrounding muscle; 2) during consolidation, angiogenesis predominated in the intraosteal region; and 3) vessel formation proceeded from the surrounding muscle into the regenerate. These data show that formation of vascular tissue occurs in both muscular and osseous compartments during DO and that periods of intense osteogenesis are concurrent with those of angiogenesis. The results further suggest the presence of morphogenetic factors that coordinate the development of vascular tissues from the intramuscular compartment into the regions of osseous regeneration.

The medial sural artery as recipient vessel and the impact on the medial gastrocnemius

Microsurgical free tissue transfer is a valuable technique for the reconstruction of soft-tissue defects around the knee, and the medial sural artery (MSA) is an ideal recipient vessel for anastomosis. Previously, the vessel has been described as the dominant supply to the medial gastrocnemius, but no research has addressed the subsequent effect to the muscle after interruption of MSA. The volume of the postoperative medial gastrocnemius of 4 patients treated with free flap reconstruction using MSA as recipient, was assessed clinically and using magnetic resonance imaging, with muscle function assessed using a patient questionnaire, and measurement of ankle torque with concurrent electromyography. Magnetic resonance imaging volume assessment revealed the postoperative medial head of gastrocnemius proportional to its synergist of separate blood supply, the lateral gastrocnemius and functional assessment suggest little difference between limbs such that the MSA should be used with confidence as recipient vessel for free flap reconstruction of soft-tissue defects around the knee.

Blast-induced lower extremity fractures with arterial injury: prevalence and risk factors for amputation after initial limb-preserving treatment

OBJECTIVES

The purpose of this study is to determine the rate of late (secondary) amputation and to identify risk factors for amputation in injuries that were initially treated with limb preservation on the battlefield.

METHODS

A retrospective review at our institution identified 24 consecutive patients with 26 blast-induced open fractures distal to the joint that had associated arterial injuries. All injuries were initially cared for on the battlefield and during the evacuation chain of care with limb preservation protocols. All definitive orthopaedic care was provided by a single fellowship-trained orthopaedic trauma surgeon at a tertiary care stateside facility. Injury factors were analyzed based on radiographic and chart review to determine associations with amputation.

RESULTS

Twenty of 26 injured limbs received an amputation for a total amputation rate of 76.9% (95% confidence interval, 57.9-88.9%). Fourteen limbs received early amputation before limb salvage attempts. Six of the 12 limbs that received limb salvage underwent late amputation.

CONCLUSIONS

The rate of amputation in severe blast-induced extremity fractures combined with an arterial injury initially treated with limb preservation on the battlefield and before transfer to the definitive military treatment facility is extremely high. Blast-injured lower limbs with a combined severe bony and soft tissue injury should be carefully assessed when arterial injury is present because they may require early amputation during initial surgical care on the battlefield.

Zone of injury: a critical review of the literature

The response of tissue to trauma is difficult to define. The zone of injury is an area surrounding a wound that, though traumatized, may not appear nonviable at initial debridement. Because of this, a policy of repeated debridements has been followed to monitor tissues for viability before final tissue coverage. Appreciation of the zone of injury has led to a controversy in the literature about how to define and approach the management of traumatic injuries requiring free-tissue coverage. This review examines the current literature with regard to the definition of the zone of injury, and seeks to establish a consensus statement about the application of free flaps to traumatized wounds. We have investigated the literature supporting the use of free flaps relying on proximally or distally based recipient vessels. Critical appraisal of this literature includes study design, determination of the power of the study, subject classification, inclusion and exclusion criteria, follow-up, and outcomes (free flap success). There has been little attempt in the literature to fully and objectively define the zone of injury. All studies to date have been observational alone. Although it would be impossible to rid a definition of the zone of injury of subjectivity entirely, a more objective, reproducible definition is vitally needed. Without a clear definition of what the zone of injury is, there can only be anecdotal, technique reports of the placement of free flap anastomoses. In this time of rising costs and lower reimbursements, this is one area that could provide vital information to improve care for patients, lessen costs, and further medical knowledge.

Selection of the recipient vein in microvascular flap reconstruction of the lower extremity: analysis of 362 free-tissue transfers

Venous insufficiency is the most common cause of re-exploration in free-tissue transfers to the lower extremity. There is currently no consensus regarding the best approach to recipient vein selection. This study was designed to evaluate whether the type of venous system or the number of recipient veins would impact flap outcomes after microsurgical lower-extremity reconstruction. A retrospective study was conducted in 362 free-tissue transfers for lower-extremity reconstruction between 2003 and 2008. Flap outcomes were evaluated according to the selection of recipient vein system and number of veins. The deep venous system (80.4%) was more frequently selected than the superficial venous system (12.1%) or the combination of both systems (7.5%). In addition, one vein (65.5%) was more commonly used for anastomosis than two veins (34.5%). A total of 26 flaps (7.2%) presented with postoperative venous insufficiency. Male patients, composite defects including bones and the use of bone flaps presented higher rates of venous insufficiency with statistical significance. However, no significant differences were found among the different groups related to the age of patients, co-morbidities, aetiology, location of the defects or timing of reconstruction after trauma. The superficial venous system group was associated with a higher rate of venous insufficiency and partial flap loss compared with the deep venous system group (p = 0.036 and 0.018, respectively). One-vein-anastomosis flaps were associated with statistically significant fewer complete flap failure in comparison with two-vein-anastomosis flaps (p = 0.014). In conclusion, the assessment of recipient vein parameters by surgeon's experience is the best predictor of flap outcome in lower-extremity reconstruction. In our cohort of patients, the deep venous system was more reliable than the superficial venous system, but the use of more than one vein for anastomosis did not correlate with better flap outcomes.

Multiple spurting test in microsurgical reconstruction of the lower extremities

Appropriate recipient artery is essential for the success of free flap reconstruction, however the selection could be difficult in a traumatized lower extremity. To detect unnoticed damage of the recipient artery, vascular integrity should be verified. For that purpose, we propose a simple and effective evaluation method, called Multiple Spurting Test (MST) this test esteems the dynamic status of the recipient arteries by measuring the length of arterial spurting. All the microsurgeons usually do something like MST: but it is not a standardized test yet.This study analyzed if this test could be a practical method in searching a safe recipient artery during microsurgical reconstruction of lower extremity. MST was employed in 163 flaps, all for lower extremity reconstruction. Fifteen flaps were re-explored in this series. Six of them had arterial problems, three in Anterior Tibial Artery (ATA), two in Posterior Tibial Artery (PTA) and one in Sural Artery (SA). The overall series' re-exploration rate, due to different complications, was 7% when ATA has been the recipient vessel, 7.6% with PTA and 30.7% with SA. Both ATA and PTA found equally reliable after examination with MST. We do believe that MST can effectively decrease the incidence of arterial complications and flap failure. Using this method, it is easier to choose a safe recipient artery for revascularization.

Lower extremity arterial injury patterns and reconstructive outcomes in patients with severe lower extremity trauma: a 26-year review

BACKGROUND

Management of severe traumatic lower extremity injuries remains a considerable challenge. Free tissue transfer is now a standard part of reconstruction for Gustilo IIIB and IIIC injuries. There is limited information on arterial injury patterns in this population. We undertook a review of our experience to gain insight on vascular injury patterns and surgical outcomes.

STUDY DESIGN

A 26-year retrospective analysis was performed of all lower extremity Gustilo IIIB and IIIC injuries requiring microvascular reconstruction at New York University Medical Center. Patient demographics, Gustilo classification, angiographic findings (conventional/computed tomographic angiography/magnetic resonance angiography), recipient vessels, elapsed time from injury, flap choices, and outcomes were examined.

RESULTS

Two hundred twenty-two free flaps on 191 patients were performed from September 1982 until March 2008. There were 151 males and 40 females ranging in age from 4 to 83 years (median age 33 years). Patients sustained either Gustilo IIIB (170 patients) or IIIC (21 patients) open fractures. One hundred fifty-four patients had angiograms (78.2% IIIB, 100% IIIC). Sixty-six (42.9%) had normal 3-vessel runoff and 88 (57.1%) were abnormal. Sixty-one patients (31.9%) had anterior tibial injuries, 17 patients (8.9%) had posterior tibial injuries, and 30 (15.7%) had peroneal injuries. Sixty-three complications occurred (11 early thrombosis, 33 requiring secondary procedures, and 10 requiring amputation).

CONCLUSIONS

Angiography of severe lower extremity injuries requiring free flap reconstruction usually revealed arterial injury and is generally indicated. In our experience, the anterior tibial artery is most commonly injured and the posterior tibial artery is most likely to be spared and used as a recipient.

MOC-PS(SM) CME article: lower extremity reconstruction

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand the evaluation of a patient with a lower extremity wound. 2. Determine when an attempt at wound salvage is likely to be successful. 3. Select an appropriate technique for wound management. 4. Anticipate and identify wound complications.

SUMMARY

Successful management of a patient's wound at or distal to the knee includes accurate site assessment, meticulous debridement, planning, and execution of a reasonable operative procedure. Outlining a reconstructive plan requires consideration of alternatives from basic to most complex, then selection of the simplest technique likely to achieve wound closure with minimal donor-site morbidity. Healing by secondary intention, with or without vacuum-assisted closure, demands few surgical resources. A skin graft may close a well-vascularized wound. A local skin, fasciocutaneus, or muscle flap can provide vascularized tissue to an otherwise ischemic area. A plastic surgeon may use free tissue transfer in the more difficult anatomic regions, particularly for defects of the distal one-third of the lower leg. Other issues demand consideration when treating a patient with a lower extremity wound. Anesthetic options range from none in the case of secondary intention healing, through prolonged general anesthesia in the circumstance of free tissue transfer. Early recognition of a complication makes successful treatment of that problem more rapid and more likely to be successful. Accurate CPT coding ensures appropriate reimbursement for the reconstructive surgeon and fairness to the payer. Finally, some wounds are so extensive and patients so ill from related or unrelated pathologic processes that attempts at reconstruction are ill advised. These patients are better served by early amputation and prompt rehabilitation.