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

Refining a Multidisciplinary "Vasculoplastic" Approach to Limb Salvage: An Institutional Review Examining 300 Lower Extremity Free Flaps

BACKGROUND

The use of free tissue transfer (FTT) is effective for treatment of chronic nonhealing lower extremity (LE) wounds, requiring collaboration across plastic, vascular, podiatric, orthopedic, and infectious disease disciplines for comprehensive treatment plans to optimize limb salvage. The authors describe their vasculopathic approach with 300 LE FTTs, comparing outcomes between the first 200 LE FTTs and the most recent 100 procedures performed.

METHODS

A single-institution, retrospective review of 300 LE FTTs from July of 2011 to January of 2023 was performed. Patients were compared between the first 200 (group 1; July of 2011 through February of 2020) and last 100 flaps (group 2; February of 2020 through January of 2023) performed. Patient characteristics, preoperative management, intraoperative details, and outcomes were collected.

RESULTS

Group 2 patients had significantly higher rates of diabetes (67.0% versus 48.5%; P = 0.002), peripheral vascular disease (56.0% versus 24.5%; P < 0.001), history of venous thromboembolism (13.0% versus 6.0%; P = 0.039), venous reflux (81.9% versus 67.8%; P = 0.028), and preoperative venous thromboses on venous testing (25.5% versus 10.5%; P = 0.003) compared with group 1. Group 2 patients underwent more pre-FTT endovascular interventions (23.0% versus 16.5%; P = 0.039) and vascular bypasses (4.0% versus 0.0%; P = 0.012). Immediate flap success and amputation rates were similar between the groups, but group 2 had higher rates of partial flap necrosis (7% versus 3%; P = 0.012).

CONCLUSION

The adoption of a vasculoplastic approach allows LE FTT to remain successful and achieve long-term limb salvage despite a highly comorbid population.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Functional Lower Limb Salvage

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Explain the basic concept of functional limb salvage. 2. Understand the complexity of salvaging the limb when consulting the patient, especially regarding how to obtain the best possible functional outcome, whether it be from limb salvage or amputation. 3. Implement orthoplastic thinking to salvage the limb. 4. Understand the latest innovations for limb salvage.

SUMMARY

The goal of limb salvage is to have the patient achieve the best possible function that allows daily activities (eg, walking and running) and the ability to perform tasks that require strength and dexterity. This is a complex process requiring the work of a multidisciplinary team practicing the principles of good wound care, orthoplastic thinking, and strategizing on future function. Understanding the new advances in this field of rapid change and growth will help reconstructive surgeons to make better decisions and incorporate them into daily practice, allowing for the best possible outcome.

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.

Ultrasound in Microsurgery: Current Applications and New Frontiers

Ultrasound has revolutionized reconstructive microsurgery, offering real-time imaging and enhanced precision allowing for preoperative flap planning, recipient vessel identification and selection, postoperative flap monitoring, and lymphatic surgery. This narrative review of the literature provides an updated evidence-based overlook on the current applications and emerging frontiers of ultrasound in microsurgery, focusing on free tissue transfer and lymphatic surgery. Color duplex ultrasound (CDU) plays a pivotal role in preoperative flap planning and design, providing real-time imaging that enables detailed perforator mapping, perforator suitability assessment, blood flow velocity measurement, and, ultimately, flap design optimization. Ultrasound also aids in recipient vessel selection by providing assessment of caliber, patency, location, and flow velocity of recipient vessels. Postoperatively, ultrasound enables real-time monitoring of flap perfusion, providing early detection of potential flap compromise and improved flap survival rates. In lymphatic surgery, ultra-high frequency ultrasound (UHFUS) offers precise mapping and evaluation of lymphatic vessels, improving efficacy and efficiency by targeting larger dilated vessels. Integrating ultrasound into reconstructive microsurgery represents a significant advancement in the utilization of imaging in the field. With growing accessibility of devices, improved training, and technological advancements, using ultrasound as a key imaging tool offers substantial potential for the evolution of reconstructive microsurgery.

Technical Variables in Lower Extremity Free Flap Reconstruction

BACKGROUND

 Lower extremity free flap failure rates are higher than in other areas of the body. While prior studies assessed the effect of intraoperative technical variables, these generally investigated individual variables and did not examine relationships between the many individual technical decisions made during free tissue reconstruction. Our purpose was to investigate the effect of variation in intraoperative microsurgical techniques on flap outcomes in a diverse cohort of patients requiring lower extremity free flap coverage.

METHODS

 Consecutive patients undergoing free flap reconstruction of the lower extremity at two level 1 trauma centers from January 2002 to January 2020 were identified using Current Procedural Terminology codes, followed by a review of medical records. Information regarding demographics and comorbidities, indications, intraoperative technical details, and complications was collected. Outcomes of interest included an unplanned return to the operating room, arterial thrombosis, venous thrombosis, partial flap failure, and total flap failure. Bivariate analysis was performed.

RESULTS

 In total, 410 patients underwent 420 free tissue transfers. The median follow-up time was 17 months (interquartile ranges: 8.0-37). Total flap failure occurred in 4.9% (n = 20), partial flap failure in 5.9% (n = 24), and unplanned reoperation in 9.0% (n = 37), with arterial thrombosis in 3.2% (n = 13) and venous thrombosis in 5.4% (n = 22). Overall complications were significantly associated with recipient artery choice, with arteries other than PT and AT/DP having a higher rate (p = 0.033), and with arterial revisions (p = 0.010). Total flap failure was also associated with revision of the arterial anastomosis (p = 0.035), and partial flap failure was associated with recipient artery choice (p = 0.032).

CONCLUSION

 Many interoperative options and techniques are available when performing microvascular lower extremity reconstruction that leads to equally high success rates. However, the use of arterial inflow outside of the posterior tibial and anterior tibial arteries leads to a higher overall complication rate and partial flap failure rate. Intraoperative revision of the arterial anastomosis portends poorly for ultimate flap survival.

The use of double free flaps with intra-flap anastomosis for complex defects reconstruction

BACKGROUND

Over the years, the improvements in microsurgical field allowed the reconstruction of increasingly larger and more complex defects. In this context, we conceived linking more flaps with a single vascular supply. The double free flaps with intra-flap anastomosis offer a better match with recipient site requirements, still having a minimal donor and recipient site morbidity. In the present paper, we describe our experience with this procedure, focusing on its features and providing a collection of cases in different areas and clinical settings.

PATIENTS AND METHODS

Consecutive single-center case series with 16 patients who received defect reconstruction using double free flaps with intra-flap anastomosis between February 2019 and August 2021. The median age was 58 years old (range 39-77). Nine patients were men and seven were women. The defects were located throughout the body, including breast, head and neck, lower and upper limbs. In 12 cases, the cause of the defect was surgical removal of a tumor, while in four cases the cause was trauma. The main indication for this procedure was related to the need of covering a large defect, either in terms of volume or surface, resorting to only one vascular axis.

RESULTS

A total of 32 flaps were harvested, including 10 different techniques. The flaps size ranged from 6 × 3 cm to 24 × 8 cm. Eleven patients completely healed without any complications. No flaps were lost. Three patients developed a minor wound dehiscence and one a wound infection treated conservatively with antibiotic therapy. One patient experienced both of these complications. The median follow up was 12 months and ranged between 6 and 24 months. At the final clinical evaluation, the reconstructive result was stable in all cases and all the patients had a complete resumption of their daily activities.

CONCLUSIONS

Double free flaps reconstruction with intra-flap anastomosis represents a valid and reliable option for the coverage of complex defects in case of depleted recipient sites. This procedure allows us to transfer high amounts of tissue resorting to a single vascular axis. However, it represents a technical challenge and a highly experienced microsurgical team is required.

Equivalence in Color-coded Duplex Sonography Parameters before Complex Microsurgery

Background

Color-coded duplex sonography (CCDS) is a widely proposed noninvasive diagnostic tool in microsurgery. CCDS has been applied to lower extremity salvage cases to define appropriate blood flow velocity criteria for achieving arterial success in diabetic foot and complex microsurgery cases. This study aimed to compare the success ratio of free flaps when using CCDS versus cases where CCDS was not used.

Methods

We included complex microsurgery cases from 2019 to 2021. These cases were subsequently categorized into two groups: group A consisted of cases where CCDS parameters were applied, whereas group B comprised cases where CCDS was not performed at all.

Results

The study encompassed 14 cases (11 men and three women). The age range varied from 23 to 62 years, with an average age of 42. Using CCDS analysis and planning demonstrated improved outcomes in comparison with cases where CCDS was not performed, albeit without statistical significance (P = 0.064).

Conclusions

The application of CCDS proves to be beneficial in the realm of microsurgery. Although not achieving statistical significance, our data imply that CCDS utilization holds promise for enhancing microsurgical procedures.

Free Tissue Transfer to the Knee for a Complex Wound Coverage When Good Recipient Vessels Are Not Available

Free tissue transfer to the knee can be difficult due to limited options for reliable recipient vessels and vein grafts or arteriovenous loops may also be associated with an increased risk of flap failure. In this study, the authors describe our experience with creating proper recipient vessels for free flap reconstructions around the knee using the descending branch (DB) of the lateral circumflex femoral vessels (LCFV) or anterior tibial vessels (ATV). Three patients underwent free flap reconstruction of knee wounds secondary to trauma, prosthesis infection, and radiation therapy. The anterolateral thigh, rectus abdominis, and latissimus dorsi flaps were used to close the wounds, respectively. Dissection of the DB of LCFV was carried between the rectus femoris and vastus lateralis, and between the peroneus longus and brevis for the ATV. These recipient's vessels were created and placed in a more desirable location adjacent to the defect for microvascular anastomoses. The DB of LCFV and ATV were dissected successfully and both arterial and venous micro-anastomose were performed in an end-to-end manner with the recipient's vessels. All patients had successful free tissue reconstructions with uneventful postoperative courses. The flaps remained viable and reliable soft tissue coverage with acceptable contour had been accomplished during follow-up. Either DB of LCFV or ATV can serve as adequate recipient vessels after being placed adjacently to soft tissue defects for a straightforward free tissue transfer to the knee. The creation of such recipient vessels avoids vein grafts or arteriovenous loops and allows for a reliable free flap reconstruction of the knee.

Study to the Effect of Involutional Blepharoptosis Surgery Using Objective and Subjective Parameters

Background  We investigate the effect of involutional blepharoptosis (IB) surgery based on dry eye symptoms by analysis using objective and subjective measures.

Methods  We recorded various parameters from patients that underwent levator advancement surgery for IB, totaling 125 eyes (total 65 patients, 5 unilateral, 60 bilateral). Subjective assessment comprised a questionnaire on dry eye-related quality of life score (DEQS), a summary score calculated from DEQS, and six-grade evaluation, the patient's own measure of eye comfort. Objective assessment comprised marginal-reflex distance-1 (MRD-1), measurement of tear film breakup time, and superficial keratopathy (SPK) existence by slit lamp microscope.

Results  Subjective assessments showed that IB patients had improvement of dry eye symptoms and eye comfort when surgery increased MRD-1. On the other hand, objective assessments showed that the presence of SPK is suspected when the postoperative MRD-1 level is 3 mm or higher.

Conclusion  IB surgery must not only increase MRD-1 value, but also to perform maintenance of the appropriate ocular surface condition. From our parameters, we suggest postoperative MRD-1 value should be maintained at < 3 mm to safe and effective of IB surgery.

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.