Selected AMPutation Prevention Symposium 2017 Abstracts

Abstracts

Submitted on Mon, 08/07/2017 - 22:42
Citation
Vascular Disease Management. 2017;14(8):e178-e188.

Abstract 1: Comparison of Particulate Embolization after Femoral Artery Treatment With In.Pact Admiral, Ranger, and Stellarex Paclitaxel-Coated Balloons in Healthy Swine

Renu Virmani, MD, President, CV Path, Gaithersburg, Maryland 

Introduction: Drug-coated balloons (DCBs) have emerged as an effective treatment for patients with symptomatic peripheral arterial disease in the femoropopliteal arteries. They have been shown to be superior to balloon angioplasty (PTA) in large, multicenter randomized trials. After the introduction of the first DCB, the Bard Peripheral Vascular Lutonix .035˝ over-the-wire DCB, there have been several entrants into the DCB market. However, multiple clinical and preclinical studies have illustrated there are differences in performance and safety between the different products. The various DCB technologies differ in their design of excipient coatings and the drug form (crystallinity) of the combinations. These design features can produce differences in effective drug delivery to target tissue while avoiding non-target effect (ie, minimize emboli). In a previously published study, the Lutonix .035˝ and the Medtronic In.Pact Admiral were tested and compared for downstream embolic events. The In.Pact DCB illustrated increased downstream embolic debris and higher paclitaxel levels. The findings of embolic debris from DCB coatings are of potential importance and may be further compounded in patients with claudication and more complex critical limb ischemia (CLI) with limited flow reserve. Information regarding embolic debris may be important in the selection of DCBs for patient care. 

Objectives: Different excipient/drug formulations unique to individual DCBs may influence embolic safety characteristics in distal non-target peripheral vascular territories through embolization of released particulates. A comparator study of three DCBs in commercial use – the In.Pact Admiral, Boston Scientific Ranger, and Spectranetics Stellarex – in healthy swine was therefore performed to assess which balloon produced more downstream emboli and tissue reaction. 

Methods: Three-times overlapping 80 mm DCBs for each device were assessed in 24 femoral arteries of 12 swine with 28-day follow-up for downstream embolic events and debris. In.Pact Admiral was used as a control, as its downstream emboli and effect have been previously studied and published. Histologic analysis of arterial wall and skeletal muscle and coronary band downstream from the external or internal femoral arteries was performed. This analysis was supported by an analytic measurement of paclitaxel levels. The gastrocnemius, gluteal, and gracilis are skeletal muscle territories distal to the external femoral artery and the coronary corium (ie, coronary band) is a highly vascularized structure that gives rise to the outer layers of the hoof wall and resembles the nail bed of a human finger. 

Results: For all DCBs tested, regions of increased proteoglycan were accompanied by the loss of medial smooth muscle cells mainly extending nearly one-third to complete transmural involvement with restricted circumferential extension. Medial fibrin was present for all cohorts. The percentage of sections with downstream vascular changes in arterioles were greatest for In.Pact > Stellarex > Ranger (43%, 36%, and 25%, respectively). Embolic crystalline material was seen for all cohorts and followed a similar trend. Drug analysis in parallel tissues illustrated the highest paclitaxel concentrations in non-target coronary band tissues for Stellarex > In.Pact > Ranger (962.3 ng/g, 911.3 ng/g, and 822.5 ng/g, respectively).

Conclusion: All DCBs tested exhibited downstream effects of paclitaxel drug and/or downstream emboli. The In.Pact control exhibited similar behavior as published from a previous study on downstream emboli. The new DCBs tested, Stellarex and Ranger, exhibited downstream vascular changes and the Stellarex DCB exhibited the highest downstream coronary band paclitaxel concentration at 28 days. The potential downstream embolic effects with certain DCB use may present a concern that may influence the selection of available catheter technologies.

Abstract 2: Distal Bypass for Critical Limb Ischemia: When Endovascular Fails

Cesar Eduardo Jimenez, MD, Chairman Vascular Surgery, Hospital Universitario Clinica San Rafael, Bogotá, Colombia

Introduction: Critical limb ischemia (CLI) of the lower limbs is a very frequent and growing entity worldwide, already considered an epidemic given the increase in diabetes, unhealthy lifestyles, and increased life expectancy of the population. CLI is characterized by the presence of pain at rest and tissue necrosis, manifested by chronic ulcers that do not heal and necrosis of the foot or fingers. These patients have a very ominous prognosis, with a high probability of limb loss and death. Treatments for CLI are based on the general condition of the patient, and the experience and availability of vascular surgeon resources. The diabetic and renal patients who usually present with CLI characteristically have severe infrapopliteal disease and to save the limb, require at least one of the three popliteal vessels below the foot to be able to maintain the viability of the limb and close wounds. Distal or ultra-distal bypass were the first treatments for this entity, with good salvage and permeability indexes, but they have been stopped to the extent that endovascular techniques have been positioned as the first line of treatment in patients with CLI. A 20%-30% infrapopliteal percutaneous angioplasty fails for different reasons; major arterial surgery should continue to be considered an option in the management of patients with CLI. It is a complex and technically demanding procedure for a vascular surgeon, but well performed, is an excellent choice for limb salvage. We present our experience in distal and ultra-distal bypass in patients who were taken to percutaneous angioplasty as the first option for limb salvage but failed. 

Objectives: The main objective of our work is to present our experience in limb salvage with distal surgical procedures and to determine the degree of limb salvage with these techniques. Secondary endpoints were morbidity and mortality associated with distal bypass. 

Methods: We performed a retrospective analysis of patients undergoing popliteal bypass for limb salvage for 2 years (January 2015 to January 2017) at a referral hospital in the city of Bogotá, Colombia for vascular pathologies. Inclusion criteria were patients with critical ischemia secondary to occlusive arterial disease of the popliteal, infrapopliteal, or both, who were taken to percutaneous angioplasty, but were not successful. The variables were age, sex, and type of bypass performed (popliteal-pedis, popliteal to posterior tibial, popliteal to anterior tibialis). The risk factors studied were diabetes mellitus, coronary artery disease, hypertension, chronic obstructive pulmonary disease (COPD), and renal insufficiency on dialysis. Complications related to bypass were analyzed (myocardial infarction, pulmonary embolism, stroke, wound infection, early graft occlusion, bleeding requiring postoperative transfusion, and renal failure), the type of graft used, minor amputations performed at the time of the bridge, amputation at 90 days and 30-day mortality from the procedure. Follow-up was clinically and with duplex at the third postoperative month. In addition, it was evaluated which patients had percutaneous angioplasty associated with the bypass, as an additional measure to optimize flow before the revascularization. Variables data were collected in an Excel database and analyzed retrospectively.

Results: We evaluated 18 patients with critical ischemia who underwent attempted percutaneous salvage angioplasty but failed. Average age was 70 years (range, 52-85 years), with 44% (n = 8) women and 55% (n = 10) men. The associated comorbidities were renal failure on dialysis 11% (n = 2), COPD 50% (n = 9), diabetes mellitus 77% (n=14), hypertension 83% (n = 15), and coronary heart disease 77% (n = 14). Bypasses performed were popliteal to posterior tibial 16% (n = 3), popliteal to anterior tibial 16% (n = 3), popliteal peroneal 30% (n = 6), and femorotibial 5.6% (n = 1). Percutaneous angioplasty associated with vascular reconstruction was performed in a segment proximal to the occlusive lesion in 38% of cases (n = 7). Vascular reconstruction with autologous vein was performed in 83% of cases (n = 15) and polytetrafluoroethylene with vein patch in 16% (n = 3); within this group, minor amputations were performed at the same time of the bypass in 61% of cases (n = 11). Digital amputation was performed in 50% of cases (n = 9) and 11% (n = 2) were transmetatarsal amputations. Within the complications, there was no early occlusion of the graft requiring surgical or endovascular revision, acute myocardial infarction was present in 5.6% of cases (n = 1), no patient had pulmonary embolism or stroke, 16% (n = 3) experienced intraoperative bleeding that required postoperative transfusion of blood, and 5.6 (n = 1) had postoperative renal failure. Major amputation was required at 90 days in 16.7% (n = 3) and 30-day mortality occurred in 5.6% (n = 1). The permeability of the 3-month graft was 83%. 

Conclusions: Open arterial surgery is still a very useful tool in limb salvage, failed angioplasty can occur, and vascular services should have other options to save the limb. Centers that claim to offer limb salvage must have surgeons with surgical and endovascular skills. Distal bypass offers a high limb salvage and low morbidity and mortality in our study.

Abstract 3: Multicenter European Experience in the Use of the Indigo Vacuum-Assisted Thrombectomy Device in Acute Limb Ischemia

Bella Huasen, MD, Preston Royal Hospital, NHS, England, UK; Alexander Massmann, PhD, Universitätsklinikum des Saarlandes, Homburg, Germany; Abdul Rahman Alvi, MD, Queens Hospital, London, UK; Steve D’Souza, MD, Lancashire University Teaching Trust, UK; Theodosios Bisdas, PhD, St. Franziskus Hospital, Muenster, Germany

Introduction: Percutaneous thrombectomy in patients with acute limb ischemia (ALI) is a challenging task. Several devices have been approved for this indication, but their effectiveness remains a matter of debate. The aim of this study is to present the first European experience with a new aspiration thrombectomy catheter.

Objectives: The Indigo device (Penumbra) is a vacuum-assisted thrombectomy catheter that enables continuous thrombus aspiration. The catheter is available in 4 different sizes (3, 5, 6 and 8 Fr). 

Methods: A retrospective case review of all patients treated with the Indigo device between January 2016 and May 2017 in four European centers was conducted. Main inclusion criterion was acute ischemia of the lower limbs (<14 days). No further exclusion criteria were used. Main measure outcome was technical success, defined as restoration of antegrade blood flow without the need for lysis or alternative thrombectomy/revascularization strategies. Secondary outcomes were any in-hospital major adverse events (myocardial infarction, stroke, or death), need for blood transfusion, and in-hospital reintervention. 

Results: Sixty-five cases of ALI were included in this study. In all cases, successful removal of the fresh clot was achieved using either 8, 6, 5 or 3 Fr Indigo aspiration catheters or a combination, without the need for additional tPA lysis. The 3 Fr catheter was able to extend into the arteries of the plantar arch. No perforation, dissection, or neurovascular damage was encountered in any of the cases. Technical success for thrombus removal was 100% for each treated vessel segment. No blood transfusions were necessary. One patient died during in-hospital stay due to heart failure and 1 patient suffered a myocardial infarction. In the post-operative follow-up, reocclusion occurred in 4% in 30 days due to rethromboembolism from secondary causes. 

Conclusions: In our experience, the Indigo device with its various size range was an easy, safe, robust, and trackable thrombectomy to remove acute soft clot causing ALI as far down as the arch of the foot. Bleeding risk was obviated because there was no need for lysis. There was no prolonged hospital stay experienced by patients with various comorbidities.

Abstract 4: One-Month Duplex Ultrasound Evaluation of Vessel Recoil After Tibial Peripheral Vascular Intervention for Critical Limb Ischemia Predicts 12-Month Target Lesion Revascularization

Theresa McGoff, BSN, Clinical Research Nurse, Michael Sumners, DO, Osama Hallak, Fadi Saab, MD, Larry Diaz-Sandoval, MD, J.A. Mustapha, MD; Metro Health – University of Michigan Health, Wyoming, Michigan 

Introduction: Late lumen loss by mechanical and biological recoil is a known mechanism of restenosis and late failure post peripheral endovascular intervention. Its evaluation by non-invasive methods such as duplex ultrasound has not been formally studied. 

Objectives: To determine if vessel recoil at 1 month post endovascular revascularization predicts target lesion revascularization (TLR) within 12 months of baseline procedure. 

Methods: A retrospective review of 238 patients (356 tibial target lesions) from the PRIME registry who underwent tibial peripheral vascular intervention (PVI) for advanced peripheral artery disease (PAD) or critical limb ischemia (CLI) between January 2013 and August of 2016 were identified. Over a 12-month follow-up, 58 lesions were identified that required TLR and were selected for analysis. The index PVI was reviewed and for each lesion the maximal balloon inflation size was recorded as the baseline measurement. Vessel size at each discrete lesion was evaluated by averaging three separate measurements of luminal diameter (proximal, mid, and distal) on duplex ultrasound at 1-month follow-up. A control group that did not require TLR at 1 year of follow-up was otherwise randomly selected from the same 356 target-lesion cohort and the same measurements were recorded. The TLR group included 53 tibial lesions, 50 of which were evaluable by duplex ultrasound (87%). The distribution included 35 in the anterior tibial (66%), 12 in the posterior tibial (23%), and 6 in the peroneal (11%). 

Results: Recoil and vessel diameter were significant predictors of reintervention within 12 months, for every 10% recoil (odds ratio, 12.76; 95% confidence interval, 11.51-14.22; P<.001). By multivariate analysis, only recoil was a significant predictor of reintervention within 12 months. A greater percentage of recoil was noted in distal vessels despite lower average inflation sizes. 

Conclusions: Vessel recoil after tibial PVI evaluated at 1-month duplex ultrasound may predict TLR in advanced PAD and CLI patients over a 12-month follow-up. Multicenter analysis with a larger sample size is warranted to further validate findings.

Abstract 5: Occlusion Perfusion Catheter: A Universal Drug Delivery Device - Next Generation

Rex Teeslink, MD; Inventor/Co-Founder/Scientific Advisor, Advanced Catheter Therapies, Chattanooga, Tennessee

Introduction: Advanced Catheter Therapies (ACT) has designed the Occlusion Perfusion catheter (OPC) to function as a universal agent-delivery system that will accommodate any therapeutic agent, including pharmaceuticals, biologics, and live cells. 

Objectives: To demonstrate the ability of the OPC to deliver an agent circumferentially and longitudinally into the media of the vessel wall, overcoming the limitations of a drug-coated balloon and/or stent. 

Methods: The OPC is a five-lumen catheter designed with proximal and distal occlusion balloons, a center space-occupying balloon, an inflow port, an outflow port, and a guidewire lumen compatible with a standard 0.014˝ wire. It is a 5 Fr catheter compatible with a 6 Fr sheath. A fiberoptic pressure sensor is incorporated into the inflow lumen to monitor treatment chamber pressure. Occlusion balloons define the treatment region. The proximal and distal occlusion balloons are inflated simultaneously to control blood flow and create a treatment chamber. In addition, they serve to prevent systemic distribution of the agent. The fourth and fifth lumens are for inflow and outflow ports located within the established treatment chamber. The trapped blood is removed from the treatment chamber by flushing with saline. The space-occupying balloon can be inflated to minimize the amount of therapeutic agent required when indicated. This balloon never touches the vessel wall. After the blood has been evacuated, the therapeutic agent is delivered. A sensor monitor controls and optimizes pressure within the chamber for penetration into the media of the vessel wall, longitudinally and circumferentially. 

Results: Confocal analysis of the vessel wall demonstrated delivery of fluorescent paclitaxel within media and adventitia, circumferentially and longitudinally. PK analysis demonstrated a straight line of 0.1 µg/mL for 72 hours. According to Axel et al, the effective range of paclitaxel is 0.0085 to 0.85 µg/mL to effect a 90% to 99% inhibition of human arterial smooth muscle cells (SMCs). Seven-day scanning electron microscopy demonstrated that paclitaxel delayed the healing effect. Twenty-eight day histology demonstrated a normal endothelium. Live cell testing demonstrated that the OPC can deliver live cells with minimal mechanical damage at a wide range of pressures. 

Conclusions: Preclinical testing conclusions: The OPC (1) delivers an agent circumferentially and longitudinally into the vessel wall; (2) delivers the effective range of paclitaxel for 90%-99% inhibition of human arterial SMCs, maintaining normal intimal endothelial function by non-coating; (3) delivers multiple agents; (4) supports multiple use in the same patient, above and below the knee; (5) offers controlled pressure within the chamber that negates the requirement for accurate balloon-to-wall measurements; (6) delivers live cells with minimal mechanical damage to the cell membrane; (7) negates blood-agent admixture; and (8) minimizes systemic effect via flushing.

Abstract 6: Implementation of Critical Limb Ischemia Clinic in an Office-Based Vascular Surgery Center

Stephanie Sheridan, Vascular Nurse Practitioner, Christopher LeSar, MD, Nicole Tinney; Vascular Institute of Chattanooga, Chattanooga, Tennessee

Introduction: There are approximately 18 million American citizens suffering with peripheral artery disease (PAD), of which an estimated 2 million have critical limb ischemia (CLI), which is the deadliest form of PAD. Predominantly in the elderly population, individuals with CLI have a high prevalence of multiple chronic comorbidities such as diabetes, hypertension, renal insufficiency, cardiovascular and cerebrovascular disease, and a history of smoking. Costing an estimated $43,000 per patient each year for clinical care alone, CLI is an economic burden. Hospitalization for an infected wound can escalate health-care cost from $19,000 to $42,000, an increase of 121%. If the limb affected is unsalvageable, the cost for amputation (nationwide population) is an estimated $10.6 billion. However, an endovascular revascularization procedure requires the patient to recuperate at home, and 2-year status post procedure, approximately 80% of these patients are walking and 90% live alone. This is in contrast to data for amputation, which shows a 2-year mortality rate of 30%-50%, with 36%-50% requiring another amputation. 

Objectives: Our goal was to implement an office-based CLI clinic aimed at the preservation of limbs and preventing amputation in high-risk populations. After researching established CLI clinics and investigating the plan of care, we created an algorithm for early intervention with the CLI population in our office and surrounding community. Utilizing that algorithm and corresponding program plan, we hope to improve quality of life for the patients we serve with early assessment, diagnosis, and intervention by revascularization, while also creating PAD awareness within the community. 

Methods: Our case study followed a 65-year-old male who presented with ischemic ulceration on the right foot with previous medical history of hypertension, coronary artery disease, dyslipidemia, and a left above-the-knee amputation with a significant history of smoking. He had a palpable femoral pulse but an absent popliteal or tibial pulse. Following angioplasty, the limb was revascularized to promote wound healing and salvage the right lower extremity. 

Results: Our CLI clinic will prevent lengthy hospitalization, improve CLI patient outcomes, and reduce avoidable despair of underdiagnosed and undertreated vascular disease. The office-based vascular practice is a necessity for the advancement of evidence-based practice in the vascular realm. 

Conclusions: The CLI clinic will improve awareness and the approach of PAD. Multiple studies show that aggressive revascularization is an essential component of prevention of amputations; nevertheless, evidence-based research is key to improving the care provided for patients with PAD who develop CLI.

Abstract 7: Patients with Critical Limb Ischemia in the Outpatient Setting

Aleksandra Kolarczyk-Haczyk, MD, Wojciech Trendel, MD, Aleksandra Blachut, MD, Maciej Pruski, Jr., MD, American Heart of Poland, Silesia, Poland; Radoslaw Stefan Kiesz, MD, San Antonio Endovascular and Heart Institute, San Antonio, Texas

Introduction: Critical limb ischemia (CLI) is a significant morbid disease defined as a severe manifestation of peripheral arterial disease (PAD) and occurs in a chronic setting with the presence of claudication symptoms over a long period. 

Objectives: The aim was to compare patients with and without CLI in baseline and long-term observation to indicate which factors should be paid particular attention. 

Methods: This is a retrospective, single-center, outpatient center registry of 96 consecutive patients with PAD, in whom endovascular procedures utilizing stents or angioplasty were performed from January 2015 to September 2016. Patients were divided into two groups: those with CLI (“CLI 1”) (n = 46) and those without (“CLI 0”) (n = 50). We compared baseline characteristics and performed long-term observation analysis. Endpoint was the composite of death, myocardial infarction (MI), stroke, target-vessel reintervention (TVR) and target-lesion reintervention (TLR), and amputation at 30 days, and 3, 6, 9, 12, and 24 months. 

Results: There were no significant differences in basic demographic and clinical characteristics between groups except higher occurrence of diabetes (72% vs 52%; P<.05), end-stage renal disease (30% vs 8%; P<.05), and presence of ulceration (30% vs 2%; P<.05) in the CLI 1 group. There was significant difference in exercising (50% vs 20%; P<.05) in the CLI 0 group. There were no differences between cardio and cerebrovascular events at 30 days from discharge. At long-term observation, there were no significant differences between groups in regard to mortality, MI, and stroke incidence. The risk of TVR (6% vs 41%; P<.05), TLR (6% vs 37%; P<.05), and amputation (0% vs 9%; P<.05) was significantly lower in the CLI 0 group when compared with the CLI 1 group. 

Conclusions: CLI occurs more often in patients with end-stage renal disease, in those on dialysis, and in patients with diabetes. Long-term observation demonstrated patients with CLI have more frequent and repeated endovascular procedures and amputations.

Abstract 8: Mirror Distribution of Lesions in the Lower Extremities in Patients with Critical Limb Ischemia

Aleksandra Kolarczyk-Haczyk, MD, Wojciech Trendel, MD, Aleksandra Blachut, MD, Maciej Pruski, Jr, MD, American Heart of Poland, Silesia, Poland; Radoslaw Stefan Kiesz, MD, San Antonio Endovascular and Heart Institute, San Antonio, Texas

Introduction: Prevalence of critical limb ischemia (CLI) is still increasing. Symptoms for CLI are resting pain with or without small ulcers to gangrene. Doppler ultrasound is the first diagnostic tool used in these patients; however, it is often performed in the symptomatic leg only. In angiography, which is the gold standard of lower-extremity vessel visualization, mirror occurrence of lesions in the arteries can be observed. 

Objectives: The aim of the study was to estimate the distribution of lesions in patients with CLI. 

Methods: This is an outpatient, single-center, retrospective study of 87 consecutive patients with CLI who underwent diagnostic lower-extremity angiography between January 2014 and December 2016. Distribution and mirror occurrence of lesions in the lower-extremity arteries were estimated. 

Results: In the registry, 52% patients were men, and mean age was 74 ± 12 years. Hypertension was present in 95%, hyperlipidemia in 90%, and diabetes in 64%. Sixty-two percent of patients had history of coronary artery disease (25% post myocardial infarction), 56% had prior peripheral arterial disease (PAD), and 18% had history of stroke. Patients were treated with aspirin, thienopyridine-class antiplatelet agents, and statins in 71%, 61%, and 69%, respectively. Fifty-four percent of patients had a history of PAD-related lower-extremity interventions (endovascular intervention, bypass surgery, or amputation in 44%, 20%, and 15%, respectively). Most of the patients (52%) were in Rutherford 4 class. Ulceration occurred in 45%. The mean probability rate of mirror lesion distribution for each vessel was 46%. The vessels with the highest percentage of mirror distribution were superficial femoral artery, anterior tibial artery, and posterior tibial artery (60%, 57%, and 55%, respectively). 

Conclusions: There is a trend for mirror distribution of lesions in CLI patients. Patients should be screened with bilateral Doppler examination, even if only one extremity is symptomatic.

Abstract 9: Revascularization of Failed Venous Bypass Grafts for Lower Extremities Using Image-Guided Atherectomy

Glen Schwartzberg, MD, Baton Rouge Clinic, Baton Rouge, Louisiana

Introduction: Patients suffering from chronically recurring total occlusions typically are candidates for venous bypass surgery; however, up to 40% of lower-extremity vein-grafts develop significant stenosis within 12 months after implantation. Bypass graft failure in patients with limb-threatening ischemia often leads to amputation. Thus, revascularization of compromised vein-grafts is essential for successful limb salvage. Imaging of plaque location and morphology by luminal angiography has its limitations in the smaller vessels used in such grafts and new modalities of imaging, such as coherent optical tomography (OCT), may provide better visualization of target tissues. 

Objectives: This study was performed to assess the utility of an OCT-guided atherectomy device (Pantheris catheter; Avinger, Inc.) in treating severely diseased saphenous vein graft lesions. 

Methods: Patients with venous bypass grafts who presented to the clinic with claudication and foot pain were examined with ultrasound to assess the level of vessel stenosis. Those with evidence of occlusion in the graft were approached to schedule atherectomy followed by balloon angioplasty, with the procedures explained fully. With consent, the procedure was conducted, with the intent to remove sufficient tissue to restore blood flow, as evidenced by inline flow to the foot. Follow-up was conducted in the clinic at regularly scheduled intervals post procedure. 

Results: Ten patients were monitored following OCT-guided atherectomy and balloon angioplasty of vein-graft occlusions. The patients were predominantly male (60%) and had a mean age of 80 years (range, 78-96 years). The source of 9 of the venous grafts was autologous; 1 was cadaveric. The mean length of the graft occlusions was 155 mm, the majority had >75% stenosis, and the time to presentation of symptoms ranged from 2 months to 16 years after the initial vein graft was constructed. Atherectomy with OCT guidance was performed successfully in all patients, with a mean fluoroscopy time of 32 minutes. There were no adverse events during the procedure or recovery. At follow-up visits, all patients had a reduction in the level of graft stenosis, as determined by Duplex imaging, with 67% of patients having <20% stenosis and 33% having 30%-40% stenosis post procedure; 1 patient was lost to follow-up. 

Conclusions: OCT-guided atherectomy is a safe and effective treatment option for restoring blood flow in failed venous bypass grafts.

Abstract 10: Revascularization of a Calcified Total Occlusion in the Superficial Femoral Artery Using Intravascular OCT Guidance and Minimal Contrast

Edward Pavillard, DO, Pottstown Memorial Medical Center, Pottstown, Pennsylvania

Introduction: Imaging to guide atherectomy of peripheral arterial lesions can reduce injury to non-diseased tissue through avoidance, but fluoroscopy requires intravenous administration of a contrast agent, which can result in contrast-induced acute kidney injury in patients with diabetes mellitus. Optical coherence tomography (OCT) uses light energy to capture images of biological tissue without the use of a contrast agent. Thus, OCT imaging has the advantage of reducing exposure to a contrast agent in order to visualize diseased and non-diseased tissue in the artery in compromised patients. 

Objectives: The objective was to assess the use of an alternative imaging modality in guiding and monitoring treatment in a patient with severe claudication in the lower extremity. 

Methods: A 76-year-old female with severe spinal stenosis and diabetes mellitus, with hypertension and a history of multiple interventions for coronary and peripheral artery disease, presented to the clinic complaining of increasing pain and swelling of both feet. Due to her status, revascularization was planned with OCT-guided devices and minimal use of fluoroscopy. 

Results: An outpatient duplex ultrasound indicated a chronic total occlusion (CTO) in the right superficial femoral artery (SFA). With patient consent, revascularization of the CTO was performed using device-centered OCT imaging. An OCT-guided CTO-crossing catheter (Ocelot; Avinger, Inc.) was used to cross the CTO. An OCT-guided atherectomy catheter (Pantheris; Avinger, Inc.) removed tissue sufficient to restore blood flow, followed by balloon angioplasty. No significant residual stenosis was noted in the treated segment of the right SFA. The patient tolerated the procedure with no adverse events and was discharged the next morning. 

Conclusions: The combination of intravascular OCT imaging and minimal fluoroscopy time permits revascularization in high-risk patient populations with minimal adverse events.

Abstract 11: From Vascular Intervention to Amputation: The Multidisciplinary Approach to Limb Salvage – A Case Presentation

Jason M. Mendivil, DPM, Foot and Ankle Physician and Surgeon, Foot and Ankle Partners of El Paso; M. Laiq Raja, MD, El Paso Cardiology Associates, PA; Lorena Henderson, NP, Critical Limb Ischemia Program, The Hospitals of Providence, El Paso, Texas

Introduction: Critical limb ischemia (CLI) affects approximately 10 million people in the United States annually and there has been an increasing demand to facilitate and improve limb salvage approaches and therapies. The prevalence of comorbidities and risk factors, especially in patients with long-standing diabetes mellitus and peripheral vascular disease, increase the risk of major amputation to the affected lower extremity. This in turn leads to a decrease in quality of life, with a documented 40% higher risk of death in patients with diabetes mellitus after an amputation. We present the case of a 57-year-old, non-diabetic male with severe left lower-extremity arterial occlusive disease and discuss the systematic, multidisciplinary approach from vascular intervention to surgical debridement. 

Objectives: The case discussed in this investigation illustrates the importance of a streamlined, multidisciplinary approach to limb salvage and treating CLI. It discusses the vascular intervention and the surgical procedure performed to the patient’s left lower extremity in order to preserve adequate tissue to keep the left foot functional for ambulation. 

Methods: The patient underwent an aortofemoral runoff on January 22, 2017 with subsequent successful recanalization of the chronically occluded left external iliac artery and common femoral artery using angioplasty and stent placement as well as recanalization of the chronically occluded left superficial femoral artery and popliteal artery using antegrade and retrograde access following angioplasty and drug-coated balloon with the Medtronic In.Pact Admiral and three-stent implantation. On April 3, 2017, the patient underwent a third toe amputation, wound debridement, and application of a bilayer wound matrix allograft to facilitate wound healing to his left lower extremity. The patient was subsequently followed up in the wound care clinic with weekly debridements, with a noted closure of all wounds on June 16, 2017, with minimal loss of tissue and minimal amputation to his left lower extremity. 

Results: The patient presented in this study shows the progression of wound healing and limb preservation, initiating with a successful revascularization procedure and timely surgical amputation and wound debridement. It illustrates the use of an advanced biologic allograft to facilitate wound healing. 

Conclusions: The authors in this investigation portray the importance of a multidisciplinary approach to limb ischemia and limb salvage. By streamlining a successful vascular intervention and surgical amputation and debridement, tissue loss can be minimized and lead to a functional limb necessary for ambulation, improving the patient’s quality of life. A systematic team approach and coordination of care are essential to bring all disciplines together for optimal outcomes.

Abstract 12: A New Closure Device: How to Close Large-Bore Sheaths with a Single Device, Leaving Nothing Behind

Rex Teeslink, MD; Inventor/Co-Founder/Medical Director, EnSite Vascular, LLC, Olathe, Kansas

Introduction: EnSite Vascular has designed the SiteSeal large-bore closure device, which simulates external compression, but removes the associated variables, leaving nothing behind. It applies invariant pressure to the vessel wall access site by utilizing internal stainless-steel springs that function as shock absorbers to dampen blood vessel pressure fluctuations. 

Objectives: To develop a closure device that would simulate external compression, but remove the associated variations. In addition, our goal was to develop a device that was not limited by sheath size, while leaving nothing behind. 

Methods: SiteSeal utilizes a number 2 Vicryl suture to make a Z stitch, which holds the SiteSeal device in place, and closes the arteriotomy site in a linear fashion. The Z stitch is placed by entering the soft tissue at the skin insertion site of the sheath. If right handed, the first entrance is 1 cm east of the sheath, passing under the sheath and exiting 1 cm west of the sheath. The second entrance is 1 cm above the skin insertion of the sheath and 1 cm to the east. The needle then crosses up and over the sheath and back down into the soft tissue, exiting 1 cm west of the sheath. The two ends of the Z stitch form a double half knot, which, when closed, creates an “X” over the arteriotomy site. Bioseal powder is placed around the sheath and half knot. The device is cocked by turning the cross bar horizontally and applying pressure, which loads the springs. It is then centered over the sheath at the arteriotomy site with the incline plane facing north. The dilator is removed from the sheath. The two suture ends are pulled tight against the sheath as pressure is applied to the device, closing the Z stitch into an “X” over the arteriotomy site, and the sheath is removed. The suture ends are pulled up through the designed slots and tied into the notched slot of the cross bar. The loaded springs are released by turning the cross bar back to a vertical position. Once the device is activated, the pressure created by the Z stitch continues to elevate the artery and folds in the soft tissues surrounding the arteriotomy site, closing the site in a linear fashion. The roof is placed and Tegaderm is applied for stabilization. 

Results: Forty-five endovascular aortic repairs (EVARs) and 23 Impella procedures have been performed using SiteSeal without any hematoma formation at discharge or at 24-hour, 7-day, and 30-day follow-up. 

Conclusions: SiteSeal does have the ability to close large-bore sheaths with a single device, leaving nothing behind. Associated advantages include: (1) not limited by sheath size, including EVAR, thoracic EVAR, and transcatheter aortic valve replacement; (2) no patient limitations, ie, size, anticoagulation, calcification, etc; (3) simple and rapid deployment; (4) allows immediate re-access; (5) minimizes patient discomfort, allowing immediate head elevation to 30° with no restriction to leg movement; (6) early ambulation; and (7) nothing is left behind – the potential of minimal risk of vessel wall injury, infection, or embolization.

Abstract 13: The Use of Hexagen Anti-Microbial Gel as an Ancillary Treatment of Necrotizing Fasciitis

Erin Koprince, DPM, Thomas Bernik, MD, Alexander Perez, DPM, Jack Yuan, DPM; Englewood Hospital and Medical Center, Englewood, New Jersey

Introduction: Necrotizing fasciitis (NF) is a rare and complicated disease, with a mortality rate between 25%-35%. Typically, an inciting trauma causes a breach in the epidermis and dermis, allowing the infecting agent to invade the soft tissue. The bacteria then aggressively attacks the adipose, fascial, and muscular layers, resulting in liquefaction of deep soft tissue layers within hours of the initial exposure. The gold-standard treatment includes emergent fasciectomy, serial debridements, broad-spectrum antibiotics, local wound care, and eventually skin grafting. In this case study, we examine the use of a novel antimicrobial formula in the treatment of the disease and give recommendations for the future. 

Objectives: To show Hexagen antimicrobial gel is an effective ancillary treatment of NF that is unresponsive to traditional therapy methods of debridement and broad-spectrum intravenous antibiotics. 

Methods: Day 1: Debridement and fasciectomy performed with subsequent white blood cell count (WBC) increase. Day 3: Second operating room (OR) debridement performed with subsequent WBC increase. Day 7: Third OR debridement with Hexagen antimicrobial gel applied to the wound base for first time, adaptic and KCI wound vac. WBC subsequently decreased for the first time during admission. After 2 days, the KCI wound vac therapy was discontinued and daily dressings of Hexagen, adaptic, and dry sterile dressings (DSDs) commenced with continued WBC decrease. Day 19: Return to OR for skin graft harvested from contralateral thigh. Hexagen applied to graft and graft stapled in place. Dressed with DSD. Daily dressing changes with Hexagen, adaptic, and DSD. Day 24: Discharged with daily Hexagen dressings. Six-week follow-up: Wound closure achieved. 

Results: The patient in this study presented with an elevated WBC count, which remained elevated throughout the period of multiple debridements until application of Hexagen antimicrobial gel. WBCs markedly decreased following the application of Hexagen. After use of this ancillary treatment infection abated, the limb was salvaged, and the patient achieved wound closure and returned to work by 6 weeks post op, thus providing support for the use of Hexagen antimicrobial therapy in NF infections as ancillary treatment for limb salvage. 

Conclusions: Our results suggest the use of Hexagen antimicrobial therapy as ancillary therapy on NF yields better outcomes than traditional treatment methods alone.

Abstract 14: Promising Therapeutic effect of Extracellular Microvesicles in Wound Healing Area

Sami G. Alsabri1, Walid O. Mari, MD1, Chien S Poon2, Ulas Sunar, PhD2, Debra A Mayes, PhD3; Richard Simman, MD1 
1Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University, Fairborn, Ohio; 2Organization Department of Biomedical, Industrial and Human Factors Engineering, Wright State University; and 3Organization Department of NeuroScience Cell Bio Physio-COSM, Boonshoft School of Medicine, Wright State University, Dayton, Ohio

Introduction: Extracellular microvesicles (EMVs) are a way of cellular communication in both of pathological and normal conditions. EMVs also play a significant regenerative role in many damaged tissues. On other hand, epidermal keratinocytes clinically play a vital role in wound re-epithelialization and closure of wounds. 

Objectives: We investigated whether EMVs enhanced cell migration and accelerated wound-healing processes. 

Methods: Spontaneously immortalized skin keratinocyte cells were stressed for 48 hours in serum-free media to enhance the release of EMVs. The EMVs were isolated and collected by ultra-centrifugation process. Wound scratch assay was used to evaluate the cell migration rate and the wound healing percentage after adding EMVs to epidermal keratinocytes culture. 

Results: At 72 hours, the wound area in the EMV-treated group demonstrated a substantial decrease in lesion area and a singular ability to repair the lesion area as compared with the control group (P<.001). The percentage of wound healing was about three times higher in the EMV-treated group (61.82 ± 2.87%) vs the control group (23.13 ± 6.12%; P<.001). Furthermore, the migration rate in the presence of EMVs (0.0069 ± 0.0007 mm2/hr) was enhanced as compared with the control group (0.0026 ± 0.0008 mm2/hr). 

Conclusions: EMVs may have a promising therapeutic effect in wound healing by promoting and enhancing cell migration, which results in accelerated wound closure.

Abstract 15: Comparative Efficacy of Autologous Platelet-Rich Plasma Versus Bone Marrow Aspirate Injection in Unreconstructable Critical limb Ischemia: A Preliminary Report

Vladimir Cojocari, MD1, Vasile Culiuc, PhD2, Dumitru Casian, PhD2, Evghenii Gutu, PhD1; Departments of 1General Surgery and 2Vascular Surgery, Organization State University of Medicine and Pharmacy, Chisinau, Republic of Moldova

Introduction: Bone marrow aspirate (BMA) and platelet-rich plasma injections have been suggested to induce neovascularization and increase leg perfusion, due to an autologous reservoir of various growth factors, allowing a reduction in amputation rate for unreconstructable critical limb ischemia (CLI) patients with diabetes-associated and non-diabetic peripheral artery disease. 

Objectives: A comparison of clinical results of autologous platelet-rich plasma, non-manipulated and minimally manipulated BMA injection efficacy in the treatment of unreconstructable CLI. 

Methods: A single-center, 7-year, retrospective, observational study accrued 33 non-reconstructable CLI cases. Patients were 42% (n = 14) Fontaine stage III and 58% Fontaine stage IV (n = 19), with 39.4% diabetic patients (n = 13). A total of 53 implantation procedures were performed via intramuscular paratibial/foot administration of platelet-rich plasma (PRP) or native, settled, or centrifuged BMA. Thirteen patients (39.4%) received >2 treatments, with a mean 2.54 reinterventions per patient. The mean volume of injected material was 73.4 ± 13.6 mL (PRP) and 66.5 ± 19.3 mL (BMA) per treatment session. Patients were followed for 33 ± 19.13 months. The assessment of clinical results was performed by evaluation of CLI Fontaine stage change, ankle-brachial index, decrease of pain, and ulcer healing. 

Results: CLI stage downgrading was obtained for 13 cases (39.4%), 2 (15.4%) of the BMA group and 11 (55%) of the PRP group. Major amputation during follow-up was performed in 4 patients (12.1%). The study found PRP injections were more frequently associated with a positive clinical outcome compared with BMA (P=.04). Our data failed to prove any association between the BMA mode of preparation and the clinical results of the treatment (P=.43). 

Conclusions: PRP injections are a simple, safe, cost-efficient, curative method to offer a chance for limb salvage in CLI patients with no opportunity for revascularization, although further studies are needed for confirmation of the results.

Abstract 16: Silver Alginates for Treatment of Chronic Wounds: Bactericidal Effect and In Vitro Tissue Compatibility

Claudia Eder, PhD1, Martina Stangl2, Peter Landowski3, Sabrina Schildboeck1, Michael Ogon1, Peter Metzger3; 1Orthopaedic Hospital Vienna Speising, 2University of Applied Sciences; and 3Krankenhaus Göttlicher Heiland, Vienna, Austria

Introduction: Due to the increase of antibiotic-resistant bacteria strains, silver alginates are increasingly applied for treatment of chronic wounds. The bactericidal effect of silver ions is well demonstrated, but Cochrane reports on their clinical efficacy remain contradictory. As the high conformability allows a close contact with the underlying tissue of the wound bed, silver ions released from the dressing may be absorbed by surrounding fibroblasts and might influence wound healing. 

Objectives: The aim of the presented study was to investigate the antimicrobial effect of silver ions on patient-derived wound swabs as well as their biological effect on proliferation, viability, and collagen synthesis of fibroblast cell cultures in vitro

Methods: A commercially available silver alginate paste (Calgitrol; Blink Health) was used for the experiments. The paste was either directly applied onto agar plates or used for the generation of conditioned medium. The bottom of a 24-well cell culture plate was aseptically covered with Calgitrol and overlaid with 1 mL of Dulbeccos Modified Eagles medium (DMEM) supplemented with 10% fetal calf serum and 2 mM L-Glutamine (cell culture experiments) resp. 1 mL Lysogeny Broth (bacterial cultures) per well. The plate was incubated at 37 °C, 5% CO2, and 90% humidity for 48 hours, followed by medium harvest, centrifugation, and filtration. Unconditioned media were used for the control groups. Antimicrobial efficacy was evaluated on Staph. aureus, Staph. epidermidis, and P. aeruginosa by measuring optical density of the culture medium at 600 nm and evaluating the number of colony forming units. The NIH 3T3 fibroblast cell line was used for assessment of biological effects. Growth curves were applied to study the effect on cell proliferation. Cell viability was analyzed via Trypan Blue dye exclusion test. A non-radioactive proliferation assay (EZ4U) was applied to study cytotoxic effects. The influence on wound healing was observed via two-dimensional scratch test. All experiments were performed in triplicate and data were analyzed using a Student’s t-test at a .05 level of significance. 

Results: Calgitrol completely suppressed bacterial proliferation in all strains tested, but demonstrated a detrimental effect on cell proliferation and viability. Twenty-four hours after addition of Calgitrol-conditioned medium, cell counts had significantly decreased and no viable cells were detected via Trypan Blue dye exclusion test. No cell proliferation was observed via EZ4U. Collagen concentration decreased from 110 ± 14 μg/mL to 56 ± 4.5 μg/mL (P<.015). While in vitro wound scratches were closed after 48 hours in the control group, no healing tendency was observed after Calgitrol application. 

Conclusions: The activation of fibroblasts and their immigration into the wound gap is a crucial step in wound healing. Silver alginate demonstrated an excellent bactericidal effect, but strongly suppressed fibroblast proliferation, migration, and collagen synthesis in vitro. Similar results are reported for keratinocytes and mesenchymal stem cells by other authors. Despite their excellent bactericidal properties, silver alginates should therefore not be uncritically used in the treatment of chronic wounds.

Abstract 17: Analysis of Radiation, Contrast, and Heparin Exposure for Clinical Trial Patients vs Non-Clinical Trial Patients

Theresa McGoff, BSN, Amanda Ruddy, BSN, Kirsten VandenBerg, RN, Judy Van Dam, BSN, Kimberly McPike, BSN, Cindy Karl, BSN, Gwennan Engen, BSN, Sara Finton, BSN, Carmen Heaney, BSN, J.A. Mustapha, MD; Metro Health – University of Michigan Health, Wyoming, Michigan

Introduction: Standardly, patients receiving treatment for peripheral artery disease (PAD) and critical limb ischemia (CLI) undergo diagnostic and/or interventional procedures exposing them to increased levels of radiation, contrast dye, and heparin. If a patient enrolls in a clinical trial, very specific parameters for imaging and clotting time are dictated by the protocol. To date, no specific research has been done to compare the exposure experienced during a standard endovascular intervention compared with a patient enrolled in a research endovascular intervention. 

Objectives: To determine if exposure to radiation, contrast, and heparin is increased for patients enrolled in a clinical trial vs patients treated per routine endovascular intervention for advanced PAD and CLI. 
Methods: A single-center, retrospective review of peripheral endovascular procedures from the PRIME registry yielded 666 non-research interventions and 137 research interventions from January 2013 to March 2016. The two groups were analyzed for procedure time, radiation exposure (fluoroscopy time and dose), contrast dye exposure, total heparin dose, and peak activated clotting time (ACT). 

Results: Non-research, routine endovascular procedures were found on average to have a significantly longer average procedure time (P<.001), higher average fluoroscopy time (P=.008), and higher median fluoroscopy dose (P<.001) vs the research procedures. Research procedures showed an increased average contrast dose over non-research procedures (P=.003). Total heparin dose and ACT were not found to be significantly different between the two groups. 

Conclusions: Despite protocols dictating the angiographic images needed for research protocols, research patients were not found to be at higher risk for radiation exposure and heparin dosing. However, the research patients were found to receive a larger average dose of contrast compared with patients not enrolled in clinical trial.

Abstract 18: Chronic Limb Ischemia in a Coronary Artery Bypass Graft Patient With Vein Harvest Site Infection: A Limb Salvage Case Study Utilizing Advanced Wound Therapies

Constantina Demou, DPM, Fernando Cruz, DPM; Medical Director, Mercy Wound Center, Specialty Wound Care, Mercy Regional Medical Center, Lorain, Ohio

Introduction: Harvesting of the long saphenous vein for coronary artery bypass surgery is the most common procedure performed on patients with ischemic heart disease. The incidence of long saphenous vein harvest site infection is reported to be between 1% and 24% in the literature. Co-morbidities including diabetes mellitus, peripheral vascular disease, obesity, smoking, and renal failure are factors that can contribute to wound complications following a vein harvest procedure. Although a rare occurrence, limb threat always remains a possibility. This case study reveals such a limb threat complication requiring advanced wound therapies for successful limb salvage. 

Objectives: To attempt limb salvage utilizing advanced wound care therapies including instillation negative pressure wound therapy (NPWT) and cryopreserved human skin allograft. 

Methods: We present the case of a 65-year-old female who sought care for a 3-month-old non-healing infected lower-extremity vein harvest site following coronary artery bypass graft surgery. Past medical history included type 2 diabetes mellitus with insulin dependence, diabetic neuropathy, coronary artery disease, peripheral vascular disease, obesity, and hypertension. On initial exam, the incision was grossly infected and gangrenous. After sharp surgical debridement in the operating room, and then an angioplasty with stenting of the popliteal artery, the patient received instillation NPWT and intravenous antibiotic therapy for a total of 4 weeks in a long-term acute care setting. Once a healthy granular bed was achieved, the patient returned to the operating room for application of a cryopreserved human skin allograft. A one-time application of cryopreserved human skin allograft was placed over muscle and fascia within the entire bed of the wound. The graft was stapled then bolstered with standard NPWT. 

Results: Despite 6-month healing rate and two additional hospital stays for treatment of Clostridium difficile and pneumonia, the patient did achieve wound closure and ultimately limb salvage with both standard and installation NPWT and one application of cryopreserved human skin allograft. These advance wound therapy treatments prove to be beneficial in complex limb salvage cases. 

Conclusions: This case demonstrates two important factors: (1) Patients undergoing coronary artery bypass graft surgery should undergo a thorough lower-extremity vascular assessment prior to the vein harvest procedure; and (2) The utilization of multiple advanced wound care therapies in conjunction with a multidisciplinary team approach leads to an increased possibility of successful limb salvage and decreased overall mortality.

Abstract 19: New Technology in Access Needles

Rex Teeslink, MD; Medical Director, Interventional Radiology, InjectiMed, Inc., Minden, Nevada

Introduction: InjectiMed has developed a unique safety needle for arterial and venous access. 

Objectives: The American Nurses Association (ANA) created ten golden rules of safety that they recommended as guidelines to follow in the design of a safety needle. InjectiMed has designed and developed the “SafetyNet,” an endovascular guidewire introducer needle that encompasses all ten of the golden rules. 

Methods: The SafetyNet access needle allows the clinician to access the patient with no change in technique, and when the guidewire is positioned at the target site, safely deploy the needle with a single hand, leaving the dominant hand free to stabilize the guidewire and control bleeding. The housing is designed for high visibility with its bright coloration. The grip at the housing/hub interface gives the clinician improved control for penetrating through scar tissue and achieving a one-wall stick. There are two bevel-up indicators – a notch on the hub, and three raised chevrons on top of the Hi-Viz housing to determine the bevel orientation without taking your eyes off the monitor. There is an echogenic tip located at the distal end of the bevel extending all the way to the end of the needle. Release tabs, when squeezed, deploy a “safety guard,” which features a movable trap biased against the needle, slides on the needle, and stops at a slight bulge at the distal end of the needle, capturing the tip. A blood containment chamber slides alongside the needle and is positioned between the rear of the safety guard and the movable trap that closes over the distal end of the chamber, protecting the needle tip as well as containing any residual blood remaining within the needle. 

Results: Multiple sites have evaluated the SafetyNet needle. The evaluations indicate 100% agreement on the uniqueness and safety functionality of the needle. 

Conclusions: Features and benefits: (1) Allows access with no change in technique; (2) Designed to be activated with a single hand; (3) Manipulate guidewire and control bleeding with free hand; (4) Brightly colored housing, allowing high visibility; (5) Grip at the housing/hub interface gives improved control; (6) Two bevel-up indicators (notch on the hub and three raised chevrons on top of the Hi-Viz housing); (7) Echogenic tip located at the distal end of the needle; and (8) Patented dual-feature safety guard designed to instantly shield sharp needle tip, contain blood in needle tip, and protect caregivers from cross contamination.

Abstract 20: Peroneal Longus Overdrive: Consideration for Recalcitrant 1st MPJ Wounds

Zachary Flynn, DPM, Lawrence DiDomenico, DPM; Organization Ankle & Foot Care Centers, Youngstown, Ohio

Introduction: Sub-1st metatarsophalangeal joint (MPJ) ulcerations are one of the most common anatomical locations a diabetic patient will have a wound. If mistreated or mismanaged, it can lead to amputation of the 1st ray, which greatly increases the risk for further amputation and limb loss. In some patients, peroneal overdrive is a subtle contributing cause of deformity and ulcerations of the foot. It is in these patients that one could see pressure loads underneath the 1st metatarsal head that are abnormal. In the diabetic population, glycosolation of tendinous structures can result in this pathology, which if not addressed appropriately can lead to a recalcitrant ulceration. 

Objectives: We present a small case series of patients who possess peroneal overdrive. These patients underwent standard wound-care protocol, surgical intervention, and closures of their wounds permanently after a minimum of 3 months follow-up. 

Methods: All patients treated within our practice with sub-1st MPJ ulcerations are evaluated for peroneal overdrive. Once the diagnosis is made, all patients enter a standard wound-care protocol consisting of offloading pneumatic walker, collagen-based wound dressing, and weekly debridement. Non-invasive vascular studies and magnetic resonance imaging are ordered on a case-by-case basis. Once wound healing is achieved, surgical correction of the deformity is performed to prevent the wound from recurring. A peroneal longus to brevis transfer is performed in an outpatient setting. A gastrocnemius recession will also be performed as clinically warranted. 

Results: All patients within the case series healed within 6-12 weeks with the standard wound-care protocol. All patients underwent a peroneal longus to brevis transfer once wound healing was achieved. At a minimum of 3-month follow-up, all wounds remained healed. As this case series shows, careful examination of all feet with wounds can increase successful wound healing and limb salvage rates. 

Conclusions: As this small case series shows, recalcitrant ulcerations of the 1st MPJ can have significant consequences for limb salvage if not appropriately treated or addressed. Proper biomechanical assessment of all patients with ulcerations is necessary to assure wounds will remain healed without risk of further amputation or limb loss.

Abstract 21: Adjunctive Therapies For Wound Healing in the Patient with Critical Limb Ischemia: Use of an Advanced Acellular Dermal Allograft as a First Line Treatment to Facilitate Wound Closure

Jason M. Mendivil, DPM; Foot and Ankle Physician and Surgeon, El Paso, Texas

Introduction: The prevalence of comorbidities and risk factors, especially in patients with longstanding diabetes mellitus and peripheral vascular disease, increases the risk of major amputation to the affected lower extremity and poses a challenge for wound healing. This often leads to a decrease in quality of life, with a documented 40% higher risk of death in patients with diabetes mellitus after an amputation. After a successful revascularization procedure by the interventionist, the podiatric surgeon and wound-care specialist is challenged to prevent amputation and infection, especially as it pertains to wounds of the lower extremity. The study follows 5 patients (2 with diabetes mellitus) with chronic, ischemic, lower-extremity ulcerations and the indication for use of an advanced acellular dermal allograft to facilitate granulation tissue formation. 

Objectives: The cases discussed in this investigation illustrate the importance of implementing an advanced wound-care modality and indications for use, in the setting of both diabetes mellitus and critical limb ischemia. It discusses the process of extensive wound debridement and application of an acellular dermal allograft in order to preserve tissue viability, facilitate wound closure, and decrease the probability of an amputation. 

Methods: The 5 patients underwent a wound debridement in the operating room setting after sustaining a successful revascularization procedure by an interventional cardiologist. An advanced acellular dermal allograft was secured to the wounds by staples and sutures, followed by a bolster-type dressing in order to facilitate intimate contact with the wound base. Due to an associated depth of the wounds, 3 patients also had a negative pressure wound therapy device applied over the allograft to facilitate graft uptake and moisture management. The wound healing progress was observed and documented. 

Results: The patients presented in this study show the progression of wound healing and limb preservation, initiating with a successful revascularization procedure and timely wound debridement. It illustrates the use of an advanced biologic allograft to facilitate wound healing as a first-line treatment modality. 

Conclusions: This investigation emphasizes the importance of implementing an advanced acellular dermal allograft to facilitate wound closure and decrease wound healing times, an approach to chronic wounds in the setting of limb ischemia and limb salvage. By utilizing an advanced biologic allograft, tissue loss can be minimized.