Long-term limb salvage and functional outcomes for patients undergoing partial calcanectomy

INTRODUCTION

Partial calcanectomy (PC) can be performed to treat chronic heel ulcers in patients with calcaneal osteomyelitis. Patients undergoing PC often have multiple comorbidities, limited mobility, and face high risk of major limb amputation. This study examined the extent of vascular diagnostic testing and interventions as well as long-term outcomes in patients undergoing PC.

METHODS

A retrospective analysis was performed on patients who underwent PC for non-healing calcaneal ulcer over a ten-year period. Demographics, comorbidities, vascular testing, and procedural data were recorded. Additional subgroup analysis was performed according to presence or absence of peripheral arterial disease (PAD). Primary outcomes were major limb amputation (above or below the knee) and mortality. Secondary outcomes included successful wound healing, time to complete wound healing, re-interventions, and change in ambulatory status.

RESULTS

A total of 157 patients underwent partial calcanectomies on 162 limbs. 78.3% of patients had diabetes mellitus and 47.8% were diagnosed with PAD. Ankle brachial index with pulse volume recording (ABI/PVR) was performed for 46.5% (73/157) of patients, arterial duplex in 44.6% (70/157), and 19.7% (31/157) had a computed tomography angiogram. Lower extremity revascularization was performed in 28.4% of limbs (46/162). Independent ambulatory status was reported in 40.1% prior to PC and decreased to 17.9% by the time of last recorded follow-up (p < .00001). Long-term amputation-free survival was significantly higher in patients without PAD at 7 years (78.4% vs 57.1%, p = .02). Multivariate logistic regression analysis demonstrated that PAD and end-stage renal disease (ESRD) increased the odds of major limb amputation (OR 3.5 and 2.8, respectively), whereas ESRD and adjuvant podiatric procedures were associated with increased mortality (OR 4.8 and 4.8, respectively).

CONCLUSION

Non-invasive vascular testing should be obtained in all patients undergoing PC, in order to stratify risk of amputation and identify candidates for revascularization. Over the long-term, patients undergoing PC face significant risk of prolonged wound healing, decline in ambulatory status, and major limb amputation.

Perioperative complications of minor and major reinterventions for peripheral arterial disease

INTRODUCTION

Patients with peripheral arterial disease (PAD) frequently require reinterventions after lower-extremity revascularization (LER) to maintain perfusion. Current Society for Vascular Surgery guidelines define reinterventions as major or minor based on the magnitude of the procedure. While prior studies have compared primary LER procedures of different magnitudes, similar studies for reinterventions have not been performed. The objective of this study is to compare perioperative outcomes associated with major and minor reinterventions.

METHODS

Patients undergoing LER for PAD at a tertiary care center from 2013 to 2017 were included. A retrospective review of electronic medical records was performed, and reinterventions were categorized as major or minor based on the procedure magnitude. Minor reinterventions included endovascular procedures and open revision with patch angioplasty, while major reinterventions were characterized by open surgical or endovascular LER with catheter-directed thrombolysis (CDT). Perioperative outcomes following LER were captured and compared for major and minor reinterventions. An additional subgroup analysis was performed comparing outcomes associated with major reinterventions stratified into open major surgical reinterventions and CDT.

RESULTS

This study included 713 patients over a mean follow-up of 2.5 years. A total of 291 patients underwent 696 ipsilateral reinterventions (range = 1-12 reinterventions). Most reinterventions were minor (72.1%, N = 502) and 27.9% (N = 194) were major. Patients receiving reinterventions had an average age of 67.2 ± 11.5 and most were white (73.5%) males (60.1%) initially treated for claudication (58.2%) and CLTI (41.8%). There was significantly higher post-operative bleeding (9.8% vs 3.4%, p = .001), arterial thrombosis (3.1% vs 1.0%, p = .047), and acute renal failure (6.2% vs 2.4%, p = .014) after major reinterventions than minor. Additionally, major reinterventions had significantly higher return to the OR (17.0% vs 11.3%, p = .046) and longer hospital stays (7.5 vs 4.3 days, p = <.0001). Overall, major reinterventions were associated with significantly increased perioperative morbidity (37.6% vs 19.7%, p ≤ .001) with no difference in perioperative mortality. In the subgroup analysis, open reinterventions resulted in significantly longer hospital stays (8.6 days vs 5.5 days, p ≤ .001) and more wound infections than CDT (11.0% vs 0%, p = .017). However, there was no other significant difference in morbidity or mortality following treatment with open surgical reinterventions or CDT.

CONCLUSIONS

In this study, major reinterventions after LER were associated with greater perioperative morbidity than minor reinterventions, with no difference in mortality. Major reinterventions performed via open surgery and CDT had similar morbidity and mortality.

Anticoagulation in patients with premature peripheral artery disease undergoing lower extremity revascularization

OBJECTIVES

Premature peripheral artery disease (PAD), defined by lower extremity revascularization (LER) at age ≤ 50 years, is associated with poor major adverse limb events. The early onset of disease is thought to be influenced by genetic factors that regulate homeostasis of the vascular wall and coagulation. The aim of this study is to investigate the effect of anticoagulation as an adjunct to antiplatelet therapy on the outcomes of LER in patients with premature PAD.

METHODS

There were 8,804 patients with premature PAD on pre- and post-operative antiplatelet therapy only and 1,236 patients on pre- and post-operative anticoagulation plus antiplatelet therapy in the Vascular Quality Initiative (VQI) peripheral vascular intervention, infra-, and suprainguinal files. Propensity score matching (2:1) was performed between patients with premature PAD who were on antiplatelet therapy and those on anticoagulation plus antiplatelet therapy. Perioperative and one-year outcomes were analyzed including reintervention, major amputation, and mortality.

RESULTS

Patients on anticoagulation were more likely to have coronary artery disease (48.7% vs 41.2%, P<.001), congestive heart failure (20.2% vs 13.1%, P<.001), and have undergone prior LER (73.9% vs 49.2%, P<.001) compared to patients on antiplatelet therapy only. They were also less likely to be independently ambulatory (74.2% vs 81.8%, P<.001) and be on a statin medication (66.8% vs 74.3%, P<.001) compared to patients on antiplatelet therapy only. Patients on anticoagulation were also less likely to be treated for claudication (38.1% vs 48.6%, P<.001), and less likely to be treated with an endovascular procedure (64.8% vs 73.8%, P<.001). After matching for baseline characteristics, there were 1,256 patients on antiplatelet therapy only and 628 patients on anticoagulation. Patients on anticoagulation were more likely to require a return to the operating room (3.7% vs 1.6%, P<.001) and had higher perioperatively mortality (1.1% vs 0.3%, P=.032), but major amputation was not significantly different (1.8% vs 1.6%, P=.798) compared to patients on antiplatelet therapy alone. At one-year, amputation-free survival was higher in patients on antiplatelets only compared to patients on anticoagulation and antiplatelet medications (87.5% vs 80.9%, log-rank P=.001).

CONCLUSION

Anticoagulation in addition to antiplatelet therapy in patients with premature PAD undergoing lower extremity revascularization is associated with increased reintervention and mortality at one year.

The Utilization of Protamine during Peripheral Vascular Interventions in the VQI

BACKGROUND

Protamine administration was shown to reduce bleeding after carotid surgery but the role of protamine during peripheral vascular interventions (PVIs) remains unknown. This study evaluates the trend and outcomes of protamine use in the Vascular Quality Initiative (VQI). Our hypothesis is that the use of protamine is associated with decreased bleeding after PVI.

METHODS

Patients undergoing elective PVI in the VQI (2016-2020) for peripheral arterial disease were reviewed and the utilization trend for protamine was described. The characteristics of patients undergoing PVI with and without protamine use were compared. After propensity score matching based on the patient's comorbidities, access site, and procedural characteristics, the perioperative outcomes of both groups were compared using multivariable Poisson regression to estimate adjusted rate ratios (aRRs) and 95% confidence intervals (95% CIs).

RESULTS

The total number of patients was 131,618 and patients who received protamine constituted 29.8% of the sample (N = 38,191). After propensity matching, the total number of patients was 94,582, and patients who received protamine constituted 28.8% of the sample (N = 27,275). Protamine use significantly increased during the study period from 5.2 to 22.9%. Before propensity score matching, patients who received protamine were more likely to be white (79% vs. 76.8, P ≤ 0.001), smokers (80.5% vs. 78.5%, P ≤ 0.001), with medical comorbidities including hypertension (88.9% vs. 88.5%, P = 0.074), congestive heart failure (20.5% vs. 19.8%, P = 0.006), and chronic obstructive pulmonary disease (28.2% vs. 26.5%). They were also more likely to be on perioperative medications such as P2Y12 inhibitors (44.3% vs. 45, P = 0.013%) and statin (77.4% vs. 76.5%, P = 0.001) compared to patients who did not receive protamine. After propensity matching, there were no significant differences between the 2 groups. There was a significant decrease in bleeding during procedures where protamine was administered compared to no protamine (2.0% vs. 2.2%) (aRR, 0.89 [95% CI 0.80, 0.98]). Protamine was more likely to be given in procedures complicated by perforation (0.8% vs. 0.5%) (aRR, 1.48 [95% CI 1.24, 1.76]) and less likely to be given during procedures with distal embolization (0.4% vs. 0.7%) (aRR, 0.59 [95% CI 0.49, 0.73]). However, patients receiving protamine had significantly higher cardiac complications (1.4% vs. 1.1%) (aRR, 1.27 [95% CI 1.12, 1.43]). There was no significant difference in mortality between the 2 groups.

CONCLUSIONS

Protamine use is associated with decreased perioperative bleeding but increased cardiac complications. Protamine should be selectively administered to patients at high risk of bleeding during PVI.

Smooth muscle cell-specific MMP-3 deletion reduces osteogenic transformation and medial artery calcification

AIMS

Vascular calcification is highly prevalent in atherosclerosis, diabetes, and chronic kidney disease. It is associated with increased morbidity and mortality in patients with cardiovascular disease. Matrix metalloproteinase 3 (MMP-3), also known as stromelysin-1, is part of the large matrix metalloproteinase family. It can degrade extracellular matrix components of the arterial wall including elastin, which plays a central role in medial calcification. In this study, we sought to determine the role of MMP-3 in medial calcification.

METHODS AND RESULTS

We found that MMP-3 was increased in rodent models of medial calcification as well as in vascular smooth muscle cells (SMCs) cultured in a phosphate calcification medium. It was also highly expressed in calcified tibial arteries from patients with peripheral arterial disease (PAD). Knockdown and inhibition of MMP-3 suppressed phosphate-induced SMC osteogenic transformation and calcification, whereas the addition of a recombinant MMP-3 protein facilitated SMC calcification. In an ex vivo organ culture model and a rodent model of medial calcification induced by vitamin D3, we found that MMP-3 deficiency significantly suppressed medial calcification in the aorta. We further found that medial calcification and osteogenic transformation were significantly reduced in SMC-specific MMP-3-deficient mice, suggesting that MMP-3 in SMCs is an important factor in this process.

CONCLUSION

These findings suggest that MMP-3 expression in vascular SMCs is an important regulator of medial calcification and that targeting MMP-3 could provide a therapeutic strategy to reduce it and address its consequences in patients with PAD.

The development of a novel endovascular grasper for challenging inferior vena cava filter retrieval

OBJECTIVE

Although inferior vena cava (IVC) filters are commonly retrieved using a snare, lateral tilt and fibrosis around struts can complicate the procedure and sometimes require the use of off-label devices. We describe the development of a novel articulating endovascular grasper designed to remove permanent and retrievable IVC filters in any configuration.

METHODS

For in vitro testing, the IVC filters were anchored to the inner wall of a flexible tube in a centered or tilted configuration. A high-contrast backlit camera view simulated the two-dimensional fluoroscopy projection during retrieval. The time from the retrieval device introduction into the camera field to complete filter retrieval was measured in seconds. The control experiment involved temporary IVC filter retrieval with a snare. There were four comparative groups: (1) retrievable filter in centered configuration; (2) retrievable filter in tilted configuration; (3) permanent filter in centered configuration; and (4) permanent filter in tilted configuration. Every experiment was repeated five times, with median retrieval time compared with the control group. For in vivo testing in a porcine model, six tilted infrarenal IVC filters were retrieved with grasper via right jugular approach. Comparison analysis between animal and patient procedures was performed for the following variables: total procedure time, the retrieval time, and fluoroscopy time.

RESULTS

The in vitro experiments showed comparable retrieval times between the experimental groups 1, 2, and 4 and the control. However, grasper removal of a centered permanent filter (group 3) required significantly less time than in the control (29 vs 79 seconds; P = .009). In the animal model, all IVC filters were retrieved using the grasper with no adverse events. The total procedure time (21.2 vs 43.5 minutes; P = .01) and the fluoroscopy time (4.3 vs 10 minutes; P = .044) were significantly shorter in the animal model compared with the patient group. Moreover, in the patient group, 16.7% of retrievals required advanced endovascular techniques, and one IVC filter could not be retrieved (success rate = 91.7%), whereas all the IVC filters were successfully retrieved in the animal model without the use of additional tools.

CONCLUSIONS

The novel endovascular grasper is effective in retrieving different types of IVC filters in different configurations and compared favorably with the snare in the in vitro model. In vivo experiments demonstrated more effective retrieval when compared with matched patient retrievals.

The radiographic relationship of the femoral head, inguinal ligament, and common femoral artery bifurcation for optimal vascular access

Objective

Common femoral artery (CFA) access is commonly used for endovascular interventions. Access site complications contribute to significant morbidity and mortality. This study characterizes the radiographic variability in the relationship of the femoral head, the inguinal ligament, and the CFA bifurcation, to identify the zone of optimal CFA access.

Methods

Human cadaver dissection of the inguinal ligament and CFA bifurcation was performed. The inguinal ligament and CFA bifurcation were marked with radiopaque pins and plain anteroposterior radiographs were obtained. Radiographic measurements of the femoral head length, the distance of the top of the femoral head to the inguinal ligament, and to the CFA bifurcation were obtained. Results were reported as percentage of femoral head covered by the inguinal ligament or the CFA bifurcation relative to the top of the femoral head. A heatmap was derived to determine a safe access zone between the inguinal ligament and CFA bifurcation.

Results

Forty-five groin dissections (male, n = 20; female, n = 25) were performed in 26 cadavers. The mean overlap of the inguinal ligament with the femoral head was 11.2 mm (range, -19.4 to 27.4 mm). There were no age (<85 vs ≥85 years) or sex-related differences. In 82.6% of cadaveric CFA exposures, there was overlap between the inguinal ligament and femoral head (mean, 27.7%; range, -85.7% to 70.1%), with 55.6% having a >25% overlap. In 11.1%, there was an overlap between the lower one-third of the femoral head and the CFA bifurcation. Cumulatively, heatmap analysis depicted a >80% likelihood of avoiding the inguinal ligament and CFA bifurcation below the midpoint of the femoral head.

Conclusions

Significant variability exists in the relationship between the inguinal ligament, CFA bifurcation, and the femoral head, suggesting the lack of a consistently safe access zone. The safest access zone in >80% of patients lies below the radiographic midpoint of the femoral head and the inferior aspect of the femoral head.

An ultrasound-based femoral artery calcification score

Objective

Duplex ultrasound (US) of the lower extremities is commonly used to assess patients with lower extremity atherosclerosis. Arterial calcification can often be visualized in these images; however, efforts to quantify its extent have been limited. We, thus, sought to develop a new scoring system to measure calcification on duplex US studies of the femoral artery and correlate it with standard computed tomography (CT)-based methods. We then made preliminary attempts to correlate US-based femoral artery calcification scores with limb-specific outcomes in patients with peripheral arterial disease.

Methods

Patients who underwent CT evaluation of the lower extremities and arterial duplex US of either lower extremity within 6 months of each examination were included in the study. CT-based calcium scores of the femoral artery were generated using calcium scoring software. To determine the US score, five standard arterial segments (ie, common femoral artery, proximal superficial femoral artery [SFA], mid-SFA, distal SFA, and above the knee popliteal artery) were scored using a scale of 0 to 2 (0, a completely normal vessel segment; 1, a vessel with hyperechoic irregularities of the vessel wall; and 2, clear anechoic shadowing). The available scores were then averaged to yield a single femoral calcium score for each leg. Predictors of femoral calcification scores were then assessed and compared with the CT-based methods. The correlation between the US- and CT-based femoral calcification was assessed, and then the association between the US-based femoral calcification score and limb outcomes was evaluated.

Results

A total of 113 patients met the inclusion criteria and were included in the final analysis. US-based calcification scores were increased in patients with diabetes, renal failure, and the presence of chronic limb threatening ischemia similar to CT-based femoral calcification. The US- and CT-based calcification scores showed a moderate to strong correlation (r = 0.64). An elevated US-based femoral artery calcification score was associated with decreased amputation-free survival.

Conclusions

A novel US-based method shows promise as a simple method for quantifying the extent of femoral artery calcification in patients with peripheral arterial disease. The US-based method correlates with standard CT-based methods. Preliminary studies show that it could be useful for predicating outcomes for patients with peripheral arterial disease.

Arterial dissection during peripheral vascular interventions

OBJECTIVE

Arterial dissection (AD) is a known complication of peripheral vascular interventions (PVIs), but its incidence and significance have not been well-characterized. This study examines AD in the Vascular Quality Initiative database for patients treated for peripheral arterial disease. Our hypothesis is that AD is associated with decreased patency and worse limb outcomes.

METHODS

The Vascular Quality Initiative PVI registry (2016-2021) was reviewed. Patients were divided based on the presence or absence of reported AD during the procedure. Trend of incidence and management of AD was derived. The characteristics and outcomes of patients with and without AD were compared. The primary endpoint was primary patency.

RESULTS

There was a total of 177,790 cases, and 3% had AD. The incidence of AD significantly increased over the study period from 2.4% to 3.6% (P = .007). Endovascular therapy was used to treat AD in 83.7% of cases, 14.5% were treated medically, and only 1.8% required open surgery. Patients with AD were significantly more likely to be female (47.4% vs 39.7%; P < .001). Patient with AD were more likely to have a history of smoking (79.7% vs 77.2%; P < .001), but were significantly less likely to be on dialysis (8.2% vs 9.3%; P < .001) compared with patients without AD. Patients with AD were more likely to have femoropopliteal disease (45.2% vs 38.0%; P < .001) and undergo treatment of more complex disease as denoted by higher mean number of lesions treated (1.95 ± 1.01 vs 1.71 ± 0.89; P < .001), longer occlusion length (8 ± 16 vs 7 ± 15 cm; P < .001), and more severe TransAtlantic Inter-Society Consensus grade (Grade D: 36.2% vs 29.1%; P < .001). The proportion of stenting as a treatment modality was higher in the dissection group (55.4% vs 41.1%; P < .001). After a mean follow-up of 828 days, patients with AD had significantly lower primary patency than patients without AD. Kaplan-Meier curves demonstrated that the AD group had lower primary patency (86.9% vs 91%; P < .001) and reintervention-free survival (79.5 % vs 84.1%; P < .001) at 1 year with difference in amputation-free survival. Cox proportional hazard regression confirmed the independent association of AD with primary patency and reintervention-free survival.

CONCLUSIONS

AD is more common in women and is more likely to occur during treatment of the femoropopliteal segment. AD is associated with decreased primary patency and reintervention-free survival after PVI for peripheral arterial disease.

The Impact of Ejection Fraction on Major Adverse Limb Events after Lower Extremity Revascularization

BACKGROUND

Peripheral arterial disease (PAD) is commonly associated with coronary artery disease, and echocardiography is frequently performed before lower extremity revascularization (LER). However, the incidence of various echocardiographic findings in patients with PAD and their impact on the outcomes of LER has not been well studied. Reduced ejection fraction (EF) ≤ 40% is associated with increased major adverse limb events (MALE) after LER.

METHODS

The electronic medical records of patients undergoing LER in a single center were reviewed. Patients were divided based on the presence or absence of reduced EF. Patient, transthoracic echocardiogram, procedural characteristics, and outcomes were compared between the 2 groups.

RESULTS

A total of 1,114 patients (N = 131, 11.8% with reduced EF) underwent LER between 2013 and 2019. Patients with reduced EF were more likely to be male and have a history of coronary artery disease and heart failure. Furthermore, they were more likely to have diastolic dysfunction with moderate to severe mitral and tricuspid valve regurgitation. Patients with reduced EF were more likely to undergo LER for chronic limb-threatening ischemia, and to be treated with endovascular procedures. Perioperatively, patients with reduced EF were more likely to develop myocardial infarction. Lastly, the 2 groups had no difference in overall MALE or major amputation. However, on Kaplan-Meier curves, MALE-free survival was significantly lower for patients with reduced EF. Regression analysis demonstrated that indication and not EF was associated with MALE and MALE-free survival.

CONCLUSIONS

Reduced EF is associated with decreased MALE-free survival for patients with PAD undergoing LER.

Systematic review of inferior vena cava atresia

OBJECTIVE

Inferior vena cava (IVC) atresia is a rare venous anomaly characterized by absence of the IVC. It has been associated with deep vein thrombosis (DVT) and other congenital anomalies. The aim of the present study is to provide a comprehensive summary of the literature on IVC atresia and discuss the presentation and outcomes of patients with IVC atresia.

METHODS

A systematic review of the English literature up to April 2020 was performed. The presentations and treatments reported were noted and compared between the two sexes. The IVC atresia cases were further stratified into isolated IVC atresia and IVC atresia associated with other congenital anomalies.

RESULTS

A total of 412 abstracts were screened, with 178 reports included. A total of 376 patients were analyzed. Overall, males seem to be more affected than females, with a ratio of almost 2:1 (male, 227 [64.1%]; vs female, 127 [35.8%]). However, females were more likely to have congenital IVC atresia compared with males (46.1% vs 21.3%; P < .001). The mean age at presentation was 27.9 ± 18.0 years (range, 0-77 years), with no differences between the sexes. Most patients with IVC atresia presented with DVT (n = 242 of 376; 64.3%), with the iliac veins most often affected (n = 159 of 242; 65.7%). No difference was found in the reported proportion of patients presenting with DVT between the two sexes. The symptom presentation was similar, with leg pain and swelling the most common in both sexes. The patients were treated either medically with anticoagulation or surgically (open or endovascular). No mortality was reported with isolated IVC atresia in either treatment group. However, the mortality of patients with IVC atresia associated with other congenital anomalies was 11.7%.

CONCLUSIONS

IVC atresia is more common in males but seems to have a predilection for females in the setting of other congenital anomalies. Most patients present with leg pain and swelling related to the development of DVT. Open and endovascular surgical interventions to treat IVC atresia have been reported in 18.3% of patients reviewed, with acceptable mid-term results in terms of patency and symptomatic relief.

Effect of inferior vena cava filter placement position on device complications

BACKGROUND

Indwelling inferior vena cava (IVC) filters can cause complications, including penetration into surrounding structures, migration, and thrombosis of the vena cava. Computational fluid dynamics suggests juxtarenal placement of IVC filters decreases the risk of thrombosis; however, this has not been explored clinically. The present study examines the effect of filter placement position on long-term device complications with an emphasis on IVC thrombosis. We hypothesized that IVC filters placed further caudal to the renal veins were more likely to develop long-term thrombosis.

METHODS

A retrospective review of the medical records of patients receiving IVC filters at a single tertiary center between 2008 and 2016 was performed. Patients missing follow-up or procedural imaging data were excluded. The placement procedure venograms were reviewed, and the distance from the filter apex to the more inferior renal vein was measured using reported IVC filter lengths for calibration. The patients were divided into three groups according to the tip position relative to the more inferior renal vein: at or superior (group A), 1 to 20 mm inferior (group B), and >20 mm inferior (group C). The patient and procedural characteristics and outcomes were compared between the three groups. The primary end points were IVC thrombosis and device-related mortality.

RESULTS

Of 1497 eligible patients, 267 (17.8%) were excluded. The most common placement position was group B (64.0%). The mean age was lowest in group C, followed by groups A and B (age, 59.5 years, 64.6 years, and 62.2 years, respectively; P = .003). No statistically significant differences were found in the distribution of sex or the measured comorbidities. Group C was the most likely to receive jugular access (group C, 71.7%; group A, 48.3%; group B, 62.4%; P < .001) and received more first-generation filters (group C, 58.5%; group A, 46.6%; group B, 52.5%; P = .045). The short-term (<30-day) and long-term (≥30-day) outcomes, including access site hematoma, deep vein thrombosis, and pulmonary embolism, were uncommon, with no differences between the groups. Cases of symptomatic filter penetration, migration, and fracture were rare (one, one, and three cases, respectively). Although a pattern of increasing thrombosis with more inferior placement was found, the difference between groups was not statistically significant (group A, 1.5%; group B, 1.8%; group C, 2.5%; P = .638). No cases of device-related mortality occurred. All-cause mortality after a mean follow-up of 2.6 ± 2.3 years was 41.3% and did not vary significantly between the groups (P = .051). Multivariate logistic regression revealed that placement position did not predict for short- or long-term deep vein thrombosis, pulmonary embolism, IVC thrombosis, or all-cause mortality after adjustment for the baseline patient characteristics.

CONCLUSIONS

IVC filters have low rates of short- and long-term complications, including IVC thrombosis. The placement position did not affect the occurrence of device complications in this study.

Perioperative complications following open or endovascular revascularization for chronic limb-threatening ischemia in the BEST-CLI Trial

OBJECTIVE

Anticipated perioperative morbidity is an important factor for choosing a revascularization method for chronic limb-threatening ischemia (CLTI). Our goal was to assess systemic perioperative complications of patients treated with surgical and endovascular revascularization in the Best Endovascular vs Best Surgical Therapy in Patients with CLTI (BEST-CLI) trial.

METHODS

BEST-CLI was a prospective randomized trial comparing open (OPEN) and endovascular (ENDO) revascularization strategies for patients with CLTI. Two parallel cohorts were studied: Cohort 1 included patients with adequate single-segment great saphenous vein (SSGSV), whereas Cohort 2 included those without SSGSV. Data were queried for major adverse cardiovascular events (MACE-composite myocardial infarction, stroke, death), non-serious (non-SAEs) and serious adverse events (SAEs) (criteria-death/life-threatening/requiring hospitalization or prolongation of hospitalization/significant disability/incapacitation/affecting subject safety in trial) 30 days after the procedure. Per protocol analysis was used (intervention received without crossover), and risk-adjusted analysis was performed.

RESULTS

There were 1367 patients (662 OPEN, 705 ENDO) in Cohort 1 and 379 patients (188 OPEN, 191 ENDO) in Cohort 2. Thirty-day mortality in Cohort 1 was 1.5% (OPEN 1.8%; ENDO 1.3%) and in Cohort 2 was 1.3% (2.7% OPEN; 0% ENDO). MACE in Cohort 1 was 4.7% for OPEN vs 3.13% for ENDO (P = .14), and in Cohort 2, was 4.28% for OPEN and 1.05% for ENDO (P = .15). On risk-adjusted analysis, there was no difference in 30-day MACE for OPEN vs ENDO for Cohort 1 (hazard ratio [HR] 1.5; 95% confidence interval [CI], 0.85-2.64; P = .16) or Cohort 2 (HR, 2.17; 95% CI, 0.48-9.88; P = .31). The incidence of acute renal failure was similar across interventions; in Cohort 1 it was 3.6% for OPEN vs 2.1% for ENDO (HR, 1.6; 95% CI, 0.85-3.12; P = .14), and in Cohort 2, it was 4.2% OPEN vs 1.6% ENDO (HR, 2.86; 95% CI, 0.75-10.8; P = .12). The occurrence of venous thromboembolism was low overall and was similar between groups in Cohort 1 (OPEN 0.9%; ENDO 0.4%) and Cohort 2 (OPEN 0.5%; ENDO 0%). Rates of any non-SAEs in Cohort 1 were 23.4% in OPEN and 17.9% in ENDO (P = .013); in Cohort 2, they were 21.8% for OPEN and 19.9% for ENDO (P = .7). Rates for any SAEs in Cohort 1 were 35.3% for OPEN and 31.6% for ENDO (P = .15); in Cohort 2, they were 25.5% for OPEN and 23.6% for ENDO (P = .72). The most common types of non-SAEs and SAEs were infection, procedural complications, and cardiovascular events.

CONCLUSIONS

In BEST-CLI, patients with CLTI who were deemed suitable candidates for open lower extremity bypass surgery had similar peri-procedural complications following either OPEN or ENDO revascularization: In such patients, concern about risk of peri-procedure complications should not be a deterrent in deciding revascularization strategy. Rather, other factors, including effectiveness in restoring perfusion and patient preference, are more relevant.

Comparison of lower extremity bypass and peripheral vascular intervention for chronic limb-threatening ischemia in the Medicare-linked Vascular Quality Initiative

OBJECTIVE

There is a relative lack of comparative effectiveness research on revascularization for patients with chronic limb-threatening ischemia (CLTI). We examined the association between lower extremity bypass (LEB) vs peripheral vascular intervention (PVI) for CLTI and 30-day and 5-year all-cause mortality and 30-day and 5-year amputation.

METHODS

Patients undergoing LEB and PVI of the below-the-knee popliteal and infrapopliteal arteries between 2014 and 2019 were queried from the Vascular Quality Initiative, and outcomes data were obtained from the Medicare claims-linked Vascular Implant Surveillance and Interventional Outcomes Network database. Propensity scores were calculated on 15 variables using a logistic regression model to control for imbalances between treatment groups. A 1:1 matching method was used. Kaplan-Meier survival curves and hierarchical Cox proportional hazards regression with a random intercept for site and operator nested in site to account for clustered data compared 30-day and 5-year all-cause mortality between groups. Thirty-day and 5-year amputation were subsequently compared using competing risk analysis to account for the competing risk of death.

RESULTS

There was a total of 2075 patients in each group. The overall mean age was 71 ± 11 years, 69% were male, and 76% were white, 18% were black, and 6% were of Hispanic ethnicity. Baseline clinical and demographic characteristics in the matched cohort were balanced between groups. There was no association between all-cause mortality over 30 days and LEB vs PVI (cumulative incidence, 2.3% vs 2.3% by Kaplan Meier; log-rank P-value = .906; hazard ratio [HR], 0.95; 95% confidence interval [CI], 0.62-1.44; P-value = .80). All-cause mortality over 5 years was lower for LEB vs PVI (cumulative incidence, 55.9% vs 60.1% by Kaplan Meier; log-rank P-value < .001; HR, 0.77; 95% CI, 0.70-0.86; P-value < .001). Accounting for competing risk of death, amputation over 30 days was also lower in LEB vs PVI (cumulative incidence function, 1.9% vs 3.0%; Fine and Gray P-value = .025; subHR, 0.63; 95% CI, 0.42-0.95; P-value = .025). There was no association between amputation over 5 years and LEB vs PVI (cumulative incidence function, 22.6% vs 23.4%; Fine and Gray P-value = .184; subHR, 0.91; 95% CI, 0.79-1.05; P-value = .184).

CONCLUSIONS

In the Vascular Quality Initiative-linked Medicare registry, LEB vs PVI for CLTI was associated with a lower risk of 30-day amputation and 5-year all-cause mortality. These results will serve as a foundation to validate recently published randomized controlled trial data, and to broaden the comparative effectiveness evidence base for CLTI.

Carbon dioxide angiography during peripheral vascular interventions is associated with decreased cardiac and renal complications in patients with chronic kidney disease

OBJECTIVE

Patients with chronic kidney disease (CKD) who undergo peripheral vascular interventions (PVI) with iodinated contrast are at higher risk of post-contrast acute kidney injury (PC-AKI). Carbon dioxide (CO2) angiography can reduce iodinated contrast volume usage in this patient population, but its impact on PC-AKI has not been studied. We hypothesize that CO2 angiography is associated with a decrease in PC-AKI in patients with advanced CKD.

METHODS

The Vascular Quality Initiative PVI dataset from 2010 to 2021 was reviewed. Only patients with advanced CKD (estimated glomular filtration rate <45 ml/min/1.73 m2) treated for peripheral arterial disease were included. Propensity matching and multivariate logistic regression based on demographics, comorbidities, CKD stage, and indications were used to compare the outcomes of patients treated with and without CO2.

RESULTS

There were 20,706 PVIs performed in patients with advanced CKD, and only 22% utilized CO2 angiography. Compared with patients treated without CO2, patients who underwent CO2 angiography were younger and less likely to be women or White, and more likely to have poor renal function, diabetes, cardiac comorbidities, and present with tissue loss. Propensity matching yielded well-matched groups with 4472 patients in each group. The procedural details after matching demonstrated 50% reduction in the volume of contrast used (32±33 vs 65±48 mL; P < .01). PVI with CO2 angiography was associated with lower rates of PC-AKI (3.9% vs 4.8%; P = .03) and cardiac complications (2.1% vs 2.9%; P = .03) without a significant difference in technical failure or major/minor amputations. Low contrast volumes (≤50 mL for CKD3, ≤20 mL for CKD4, and ≤9 mL for CKD5) are associated with reduced risk of PC-AKI (hazard ratio, 0.59; P < .01).

CONCLUSIONS

CO2 angiography reduces iodinated contrast volume usage during PVI and is associated with decreased cardiac complications and PC-AKI. CO2 angiography is underutilized and should be considered for patients with advanced CKD who require endovascular therapy.

Effect of Doxycycline on Progression of Arterial Calcification in the Noninvasive Treatment of Abdominal Aortic Aneurysm Clinical Trial (N-TA(3)CT)

BACKGROUND

Doxycycline has been shown to prevent arterial calcification via attenuation of matrix metalloproteinases (MMP) in preclinical models. We assessed the effects of doxycycline on progression of arterial calcification in patients enrolled in the Non-Invasive Treatment of Abdominal Aortic Aneurysm Clinical Trial (N-TA3CT).

METHODS

Two hundred and sixty-one patients were randomized to 100 mg doxycycline twice daily or placebo. Arterial calcification was measured in abdominal vessels on noncontrast computed tomography scans. Patients with baseline computed tomography scan and 1 or more follow-up scans within the 2-year study were included for analysis. For individual arteries, mean change in iliofemoral artery calcification over time was calculated via linear regression. Serum MMP-3 and MMP-9 levels were measured at baseline and 6 months.

RESULTS

Sixty-five patients in the doxycycline and 66 in the placebo arm were included in this analysis. Baseline characteristics between the groups were similar. The unadjusted mean change in iliofemoral calcium score per year trended toward higher values in patients treated with doxycycline compared with placebo (322 ± 399 units/year vs. 217 ± 307 units/year, P = 0.09). After 6 months, changes in serum MMP-3 and MMP-9 levels were not significantly different between study arms.

CONCLUSIONS

In patients with small aortic aneurysm, treatment with doxycycline 100 mg twice daily did not decrease circulating levels of the matrix degrading enzymes MMP-3 and 9 or alter the progression of arterial calcification.

Prevalence and Characteristics of Patients with Median Arcuate Ligament Syndrome in a Cohort Diagnosed with Celiac Artery Compression

BACKGROUND

Median arcuate ligament syndrome (MALS) is a frequent differential diagnosis in patients with postprandial abdominal symptoms, but diagnosis remains challenging. The aim of this study was to identify characteristics of patients who had MALS compared with non-MALS patients among a cohort of patients diagnosed with celiac artery compression (CAC).

STUDY DESIGN

An IRB-approved retrospective chart review (2000 to 2021) of patients at our institution with a discharge diagnosis of CAC was performed. Medical record review for clinical symptoms and findings consistent with MALS was performed.

RESULTS

Two hundred ninety-three patients with a diagnosis of CAC were identified; 59.7% were women, and average age was 63.9 ± 20.2 years. Sixty-nine (23.5%) patients with CAC had MALS. There were no significant differences in sex or race between MALS and non-MALS patients, but MALS patients were younger (55.7 vs 68.1, p < 0.001). There was no significant difference in gastrointestinal comorbidities between the 2 groups. Patients with MALS were less likely to have diabetes (12.5% vs 26.9%), renal disease (4.6% vs 8.2%), hypertension (41.5% vs 70.3%), mesenteric atherosclerotic disease (14% vs 61.9%), and peripheral artery disease (15.0% vs 39.7%).

CONCLUSIONS

We demonstrate a novel observation that MALS patients tend to have fewer atherosclerotic characteristics than non-MALS patients with CAC. Patients in our study with MALS were more likely to be younger, women, and presenting with epigastric pain. MALS patients had a significantly lower incidence of diabetes, hypertension, renal disease, mesenteric artery disease, and peripheral arterial disease compared with the non-MALS group. An important clinically relevant feature of MALS patients may be their lack of atherosclerotic phenotype compared with non- MALS patients with CAC.

Iliac branch endoprosthesis for repair of a common iliac artery aneurysm in Loeys-Dietz syndrome type 3

The commercial availability of the iliac branch endoprosthesis (IBE) has permitted endovascular repair of iliac artery aneurysms with the preservation of pelvic circulation. However, the device instructions for use require certain anatomic criteria that can limit deployment in ≤30% of patients. Moreover, branched endovascular treatment of common iliac artery aneurysms with IBE in patients with connective tissue disorders such as Loeys-Dietz syndrome has not been described. In the present report, we have described our technique of alternative endograft aortoiliac reconstruction to overcome anatomic barriers to IBE placement in a patient with a giant common iliac artery aneurysm in the setting of a rare pathogenic variant in the SMAD3 gene.

The Management of Patients with Popliteal Artery Aneurysms Presenting with Acute Limb Ischemia

INTRODUCTION

Endovascular popliteal artery aneurysm (PAA) repair has acceptable outcomes compared to open repair for elective therapy. Endovascular repair for urgent PAA causing acute limb ischemia (ALI) has not been well studied. This project compares outcomes of urgent endovascular and open repair of PAA with ALI.

METHODS

The Vascular Quality Initiative database for peripheral vascular interventions and infrainguinal bypass were reviewed for PAA with ALI from 2010 to 2021. Only patients entered as having symptoms of ALI in the PVI module and ALI as indication in the infrainguinal bypass module were included. In addition, patients undergoing elective treatment were excluded and the sample analyzed was restricted to patients undergoing urgent and emergent open and endovascular repair. Patient demographics and comorbidities as well as procedural details were compared between the two groups. Perioperative complications up to 30 days were compared as well as long-term outcomes including major amputation and mortality at one year.

RESULTS

Urgent PAA repair for ALI constituted 10.5% (N=571) of all PAA. Most urgent repairs were open (80.6%, n=460) with 19.4% (n=111) endovascular. The proportion of endovascular repair significantly increased from 16.7% in 2010 to 85.7% in 2021. Patients undergoing endovascular repair were older (71.2 ± 12.5 vs 68.0 ± 11.8, p=0.011) than patients undergoing open repair. They were also more likely to have coronary artery disease (32.4% vs 21.7%, p=0.006). Open PAA repair was associated with more bleeding complications (20.8% vs 2.7%, p<0.001), longer post-op length of stay (8.1 ± 9.3 days vs 4.9 ± 5.6 days, p<0.001), and less likelihood of discharge to home (64.9% vs 70.3%, p=0.051). Perioperative major amputation rate was 7.5% with no difference between the two treatment strategies up to one year. However, patients receiving endovascular repair had higher inpatient (1.1% vs 0%, p<0.001), 30-day (6.3% vs 0.4%, p<0.001), and 1-year (16.5% vs 8.4%. P=0.02) mortality. Multivariable regression analysis suggested that endovascular repair was possibly associated with increased 30-day mortality, but not 1-year mortality.

CONCLUSION

Endovascular PAA has exponentially increased from 2010 to 2021. Endovascular repair is associated with decreased complications and hospital length of stay. The increased perioperative mortality seen in this group is likely due to selection bias.

Utility of Hook Sign in the Diagnosis of Median Arcuate Ligament Syndrome

OBJECTIVE

Median arcuate ligament syndrome (MALS) is a clinical syndrome caused by compression of the celiac artery by the median arcuate ligament (MAL) that often manifests with non-specific abdominal pain. Identification of this syndrome is often dependent on imaging of compression and upward bending of the celiac artery by lateral CTA, the so-called "hook sign." The purpose of this study was to assess the relationship of radiologic characteristicss of the celiac artery to clinically relevant MALS.

DESIGN

Single-center retrospective study METHODS: An IRB-approved retrospective chart review from 2000-2021 of 293 patients at a tertiary academic center diagnosed with celiac artery compression (CAC) was performed. Patient demographics and symptoms of 69 patients who were diagnosed with symptomatic MALS were compared to 224 patients without MALS (but with CAC) per electronic medical record review. CTA images were reviewed and the fold angle (FA) was measured. The presence of a hook sign (defined as a visual fold angle < 135 degrees) was recorded as well as stenosis (defined as >50% of luminal narrowing on imaging). Wilcoxon rank sum test and Chi-squared were utilized for comparative analysis. Logistic model was run to relate the presence of MALS with comorbidities and radiographic findings.

RESULTS

Imaging was available in 59 patients (25 males, 34 females) and 157 patients (60 males, 97 females) with and without MALS respectively. Patients with MALS were more likely to have a more severe FA (120.7 ± 33.6 vs. 134.8 ± 27.9, P = 0.002). Males with MALS were also more likely to have a more severe FA compared with males without MALS (111.1 ± 33.7 vs. 130.4 ± 30.4, P = 0.015). In patients with BMI > 25, MALS patients also had narrower FA compared with patients without MALS (112.6 ± 30.5 vs. 131.7 ± 30.3, P = 0.001). The FA was negatively correlated with BMI in patients with CAC . The hook sign and stenosis were associated with diagnosis of MALS (59.3% vs. 28.7%, P < 0.001, and 75.7% vs. 45.2%, P < 0.001, respectively). In logistic regression, pain, stenosis and a narrow FA were statistically significant predictors of the presence of MALS.

CONCLUSIONS

The upward deflection of the celiac artery in patients with MALS is more severe compared with patients without MALS. Consistent with prior literature, this bending of the celiac artery is negatively correlated with BMI in patients with and without MALS. When demographic variables and comorbidities are considered, a narrow FA is a statistically significant predictor of MALS. Regardless of MALS diagnosis, a hook sign was associated with narrower FA. While demographics and imaging findings may inform MALS diagnosis, clinicians should not rely on a visual assessment of a hook sign but should quantitatively measure the anatomic bending angle of the celiac artery to assist with the diagnosis and understand the outcomes.

Incidence and Significance of Deep Venous Reflux in Patients Treated with Saphenous Vein Ablation

BACKGROUND

Venous ablation (VA) of the saphenous vein is the most common procedure performed for venous insufficiency. The incidence of concomitant deep venous reflux (DVR) in patients undergoing VA is unknown. Our hypothesis is that patients undergoing saphenous VA with concomitant DVR exhibit a higher clinical, etiology, anatomy, and pathophysiology (CEAP) stage and less relief after VA compared to patients without DVR.

METHODS

Electronic medical records of patients treated with saphenous VA at a tertiary care center from March 2012 to June 2016 were reviewed. Patients were divided into 2 groups based on presence or absence of DVR on initial ultrasound (US) before saphenous VA. Patient characteristics and outcomes were compared. A telephone survey was conducted to assess long-term symptomatic relief, compliance with compression, and pain medication use. Subgroup analysis of patients with post-thrombotic versus primary DVR was performed.

RESULTS

362 patients underwent 497 ablations, and the incidence of DVR (>1 sec) was 20% (N = 71). Patients with DVR were significantly more likely to be male (46.4% vs. 32.1%, P = 0.021) and of Black race (21.2% vs. 5.5%, P = 0.0001) compared to patients without DVR. Patients with DVR were more likely to have a history of deep vein thrombosis (DVT) (15.1% vs. 7.9%, P = 0.045), but there was no difference in other comorbidities. There was no significant difference in presenting symptoms, CEAP stage, or symptom severity based on numeric rating scale (NRS) (0-10) for pain and swelling. Clinical success of saphenous VA was comparable between the 2 groups, but patients with DVR were more likely to develop endovenous heat-induced thrombosis (EHIT) II-IV (6% vs. 1%, P = 0.002). After a mean follow-up of 26 months, there was still no difference in pain or swelling scores, but patients with DVR were more likely to use compression stockings and used them more frequently. Only 11 of 71 patients with DVR had a history of DVT. Patients with post-thrombotic DVR were significantly older than patients with primary DVR (67.3 vs. 57.2, P = 0.038) and exhibited a trend toward more advanced venous disease (C4-C6: 45.4% vs. 33.3%, P = 0.439).

CONCLUSIONS

In this study, 20% of patients undergoing saphenous VA demonstrated DVR, which was more common in Black men. Presence of DVR is associated with increased risk of EHIT after saphenous VA but does not seem to impact disease severity or clinical relief after ablation. Larger studies are needed to understand outcome differences between post-thrombotic and primary DVR.

Real-world abdominal aorta aneurysm screening patterns among patients with new or worsening of symptomatic peripheral artery disease

BACKGROUND

Patients with peripheral artery disease (PAD) have an increased risk of abdominal aortic aneurysms (AAA), but it remains unclear whether practitioners are screening patients for AAA as part of routine PAD management.

METHODS

The Patient-centered Outcomes Related to Treatment Practices in Peripheral Arterial Disease (PORTRAIT) Registry is an international prospective registry of patients with new or worsening PAD symptoms presenting to 16 specialty centers in the United States, Netherlands, and Australia, from June 2011 to December 2015. Patients were stratified by AAA screening or AAA positivity. An adjusted median odds ratio was calculated for AAA screening rates across sites.

RESULTS

Of the 1275 patients in the study, 871 (68%) were screened for AAA, with 53 (6.1%) having AAA. AAA screening rates did not differ significantly by country (p = 0.36), but there was a large variation across sites for documentation of AAA screening with an adjusted median odds ratio 12.0 (95% CI 4.7-93.1), with AAA screening rates ranging from 7% to 100% across vascular specialty centers.

CONCLUSIONS

Among patients with PAD in a multicenter registry, over two-thirds were screened for AAA, with 6% having documented aneurysms. A large variation was seen across clinical sites, suggesting efforts are needed to increase awareness for guideline implementation and establish new benefit-risk evidence inclusive of high-risk populations such as patients with PAD.

Endovascular fenestration and iliac stenting for acute limb ischemia caused by type B aortic dissection

A 60-year-old man presented with chest pain and acute limb ischemia of the right leg. He was found to have a type B aortic dissection with a flap occluding the origin of the right common iliac artery. The dissection flap was fenestrated endovascularly with the placement of a covered stent in the right common iliac artery. After 10 years, the dissection remains stable with a minimal increase in the aorta size. The stent is patent with no lower extremity symptoms or reintervention. Fenestration and stenting of the obstructing flap can be a durable reperfusion strategy for patients with aortic dissection presenting with acute limb ischemia.

Characteristics and One-year Outcomes of Patients with Rupture of Small Abdominal Aortic Aneurysms

OBJECTIVES

Rupture of abdominal aortic aneurysms (rAAA) is typically associated with large sac diameter, however some patients experience rupture before reaching operative thresholds for elective repair. We aim to investigate the characteristics and outcomes of patients who experience small rAAA.

METHODS

The Vascular Quality Initiative database for open AAA repair and endovascular aneurysm repair (EVAR) from 2003-2020 were reviewed for all rAAA cases. Based on the 2018 Society for Vascular Surgery guidelines on operative size thresholds for elective repair, patients with infrarenal aneurysms <5.0cm in women or <5.5cm in men were categorized as "small rAAA." Patients who met operative thresholds or had a concomitant iliac diameter ≥3.5cm were categorized as "large rAAA.". Patient characteristics and perioperative as well as long-term outcomes were compared via univariate regression. Inverse probability of treatment weighting (IPTW) using propensity scores was employed to examine the relationship between rAAA size and adverse outcomes.

RESULTS

There were 3,962 cases that met inclusion criteria, with 12.2% small rAAA. The mean aneurysm diameter was 42.3mm and 78.5mm in the small and large rAAA groups, respectively. Patients in the small rAAA group were significantly more likely to be younger, African American, have lower BMI, and had significantly higher rates of hypertension. Small rAAA were more likely to be repaired via EVAR (p=0.001). Hypotension was significantly less likely in patients with small rAAA (p<0.001). Rates of perioperative myocardial infarction (p<0.001), total morbidity (p<0.004) and mortality (p<0.001) were significantly higher for large rAAA cases. After propensity matching, there was no significant difference in mortality between the 2 groups, but smaller rAAA was associated with lower rates of MI (OR=0.50[0.31-0.82]). On long-term follow up, no difference in mortality was noted between the two groups.

CONCLUSIONS

Patients presenting with small rAAA represent 12.2% of all rAAA and are more likely to be African American. Small rAAA is associated with similar risk of perioperative and long-term mortality compared to rupture at larger size after risk adjustment.

Medial artery calcification in peripheral artery disease

Medial artery calcification (MAC) is a distinct, highly regulated process that is often identified in small and mid-sized arteries of the lower extremities. It is associated with advanced age, diabetes, and chronic kidney disease. MAC often occurs in conjunction with atherosclerotic occlusive disease in lower extremity arteries, and when seen together or in isolation, long-term limb outcomes are negatively affected. In patients with peripheral artery disease (PAD), the extent of MAC independently correlates with major amputation and mortality rates, and it predicts poor outcomes after endovascular interventions. It is associated with increased arterial stiffness and decreased pedal perfusion. New endovascular methods aimed at treating calcified lower-extremity lesions may improve our ability to treat patients with limb-threatening ischemia. Although recent developments have increased our understanding of the mechanisms contributing to MAC, further investigations are needed to understand the role of medial calcification in PAD, and to develop strategies aimed at improving patient outcomes.

Positron Emission Tomography Imaging of Vessel Wall Matrix Metalloproteinase Activity in Abdominal Aortic Aneurysm

BACKGROUND

Matrix metalloproteinases (MMPs) play a key role in the pathogenesis of abdominal aortic aneurysm (AAA). Imaging aortic MMP activity, especially using positron emission tomography to access high sensitivity, quantitative data, could potentially improve AAA risk stratification. Here, we describe the design, synthesis, characterization, and evaluation in murine AAA and human aortic tissue of a first-in-class MMP-targeted positron emission tomography radioligand, 64Cu-RYM2.

METHODS

The broad spectrum MMP inhibitor, RYM2 was synthetized, and its potency as an MMP inhibitor was evaluated by a competitive inhibition assay. Toxicology studies were performed. Tracer biodistribution was evaluated in a murine model of AAA induced by angiotensin II infusion in Apolipoprotein E-deficient mice. 64Cu-RYM2 binding to normal and aneurysmal human aortic tissues was assessed by autoradiography.

RESULTS

RYM2 functioned as an MMP inhibitor with nanomolar affinities. Toxicology studies showed no adverse reaction in mice. Upon radiolabeling with Cu-64, the resulting tracer was stable in murine and human blood in vitro. Biodistribution and metabolite analysis in mice showed rapid renal clearance and acceptable in vivo stability. In vivo positron emission tomography/computed tomography in a murine model of AAA showed a specific aortic signal, which correlated with ex vivo measured MMP activity and Cd68 gene expression. 64Cu-RYM2 specifically bound to normal and aneurysmal human aortic tissues in correlation with MMP activity.

CONCLUSIONS

64Cu-RYM2 is a first-in-class MMP-targeted positron emission tomography tracer with favorable stability, biodistribution, performance in preclinical AAA, and importantly, specific binding to human tissues. These data set the stage for 64Cu-RYM2-based translational imaging studies of vessel wall MMP activity, and indirectly, inflammation, in AAA.

Placement and retrieval of bilateral iliac vein filters in patients with mega cava

Temporary interruption of the inferior vena cava is the recommended treatment to prevent pulmonary embolism in patients with venous thromboembolism (VTE) and active contraindications for therapeutic anticoagulation. In patients with mega cava (diameter >30 mm), temporary inferior vena cava filters are contraindicated. In the present report, we have described the successful placement and retrieval of bilateral iliac vein filters in two patients with VTE, mega cava, and active contraindications for therapeutic anticoagulation. At the last follow-up, both patients had recovered without recurrent VTE and had had all filters successfully retrieved without complications.

Endovascular revascularization of an occluded persistent sciatic artery for chronic limb-threatening ischemia in a patient with Coronavirus Disease 2019

A persistent sciatic artery (PSA) is a rare embryologic variant that usually presents with aneurysmal degeneration. This report describes a 66-year-old man with severe comorbidities who presented with right forefoot gangrene and severe acute respiratory syndrome coronavirus 2 infection. Imaging revealed a unilateral PSA with a chronic occlusion at the level of the knee joint with no aneurysm. After coronavirus disease 2019 resolution, he underwent CO₂ angiography with successful recanalization of the PSA, followed by transmetatarsal amputation that healed uneventfully. At follow-up after 16 months, he was noted to have asymptomatic thrombosis of his stent and, hence, no intervention was performed.

Aneurysmal degeneration of the hood of a cryopreserved vein allograft two years after thrombosis

Cryopreserved vein allografts are used as alternative conduits for infrainguinal bypass but are prone to aneurysmal degeneration. A 60-year-old man presented with a pulsatile, tender right groin mass 2 years after thrombosis of a cryopreserved vein jump graft emanating from a prosthetic axillary to profunda bypass. Intraoperatively, the aneurysm was consistent with isolated dilatation of the hood of the thrombosed cryopreserved vein graft. This was excised and repaired with bovine pericardial patch angioplasty. The patient recovered with no recurrence for 2 years. Aneurysmal degeneration of the cryopreserved vein allograft can occur even after graft thrombosis.

Abstract 291: Phosphodiesterase 10A Regulates Medial Artery Calcification

Vascular calcification results from deposition of calcium hydroxyapatite crystals in the vessel wall. It is highly prevalent in patients with chronic kidney disease (CKD), diabetes, and peripheral artery disease (PAD). In lower extremity arteries, elevated calcification levels are associated with an increased risk of ischemic events including amputation. The cyclic nucleotides cAMP and cGMP, controlled by distinct cyclic nucleotide phosphodiesterase (PDE) isozymes, play important regulatory roles in a variety of human diseases. Using a qPCR PDE array, we found that PDE10A was the most highly induced isoform in a rodent model of arterial calcification. PDE10A was also markedly increased in calcifying vascular smooth muscle cells (VSMCs) in vitro , calcified arteries from rodents with CKD, and calcified human tibial arteries. Knockdown or inhibition of PDE10A markedly attenuated high phosphate-induced VSMC osteogenic transformation and calcification in both rat and human VSMCs. Importantly, deficiency of PDE10A significantly decreased arterial calcification in both ex vivo aortic ring and in vivo vitamin D 3 medial calcification models. Several labs including our own have previously demonstrated that matrix metallopeptidases (MMPs) are involved in vascular calcification. Using a loss-of-function strategy and bioinformatics analysis, we found that MMP-3 expression was regulated by PDE10A in calcifying VSMCs. Our further mechanistic studies showed that PDE10A could regulate vascular calcification by controlling p38 MAPK signaling and MMP-3 activity through cGMP/PKG signaling. These findings suggest that PDE10A plays a critical role in the development of medial artery calcification, and that targeting it may provide a novel therapeutic strategy to reduce medial calcification in patients with PAD and CKD with the ultimate goal of preventing major limb amputation.

Trends in Utilization and Outcomes of Orbital, Laser, and Excisional Atherectomy for Lower Extremity Revascularization

PURPOSE

The aim of this study is to analyze the utilization pattern of atherectomy modalities and compare their outcomes.

MATERIALS AND METHODS

All patients undergoing atherectomy in the 2010-2016 Vascular Quality Initiative Database were identified. Utilization of orbital, laser, or excisional atherectomy was obtained. Characteristics and outcomes of patients treated for isolated femoropopliteal and isolated tibial disease by different modalities were compared.

RESULTS

Atherectomy use increased from 10.3% to 18.3% of all peripheral interventions (n = 122 938). Orbital atherectomy was most commonly used and increased from 59.4% in 2010 to 63.2% of all atherectomies in 2016, while laser atherectomy decreased from 19.2% to 13.1%. Atherectomy was mostly used for treatment of isolated femoropopliteal disease (51.1%), followed by combined femoropopliteal and tibial disease (25.8%) and isolated tibial disease (11.7%). In isolated femoropopliteal revascularization, excisional atherectomy was associated with higher rate of perforation (1.2%) compared with laser (0.4%) and orbital atherectomy (0.5%). The technical success of orbital atherectomy (96.7%) was lower compared with excisional atherectomy (98.7%). Concomitant stenting was significantly higher with laser atherectomy (43.0%) compared with orbital (27.2%) and excisional (26.1%) atherectomy. Nevertheless, there was no difference in 1-year primary patency, reintervention, major amputation, improvement in ambulatory status, or mortality. Multivariable analysis also demonstrated no difference in 1-year primary patency and major ipsilateral amputation among the modalities. In isolated tibial revascularization, there were no differences in perioperative outcomes among the modalities. Excisional atherectomy was associated with the highest 1-year primary patency (88.1%). After adjusting for confounders, excisional atherectomy remained associated with superior 1-year primary patency compared with orbital atherectomy (odds ratio [OR] = 2.59, 95% confidence interval [CI] = [1.18-5.68]), and excisional atherectomy remained associated with a lower rate of 1-year major ipsilateral amputation compared with laser atherectomy (OR = 0.29, 95% CI = [0.09-0.95]).

CONCLUSION

Atherectomy use has increased, driven primarily by orbital atherectomy. Despite significant variation in perioperative outcomes, there were no differences in 1-year outcomes among the different modalities when used for treating isolated femoropopliteal disease. In isolated tibial disease treatment, excisional atherectomy was associated with higher 1-year primary patency compared with orbital atherectomy and decreased major ipsilateral amputation rates compared with laser atherectomy. These differences warrant further investigation into the comparative effectiveness of atherectomy modalities in various vascular beds.

Salt-Inducible Kinase 3 Promotes Vascular Smooth Muscle Cell Proliferation and Arterial Restenosis by Regulating AKT and PKA-CREB Signaling

Objective

Arterial restenosis is the pathological narrowing of arteries after endovascular procedures, and it is an adverse event that causes patients to experience recurrent occlusive symptoms. Following angioplasty, vascular smooth muscle cells (SMCs) change their phenotype, migrate, and proliferate, resulting in neointima formation, a hallmark of arterial restenosis. SIKs (salt-inducible kinases) are a subfamily of the AMP-activated protein kinase family that play a critical role in metabolic diseases including hepatic lipogenesis and glucose metabolism. Their role in vascular pathological remodeling, however, has not been explored. In this study, we aimed to understand the role and regulation of SIK3 in vascular SMC migration, proliferation, and neointima formation.

Approach and Results

We observed that SIK3 expression was low in contractile aortic SMCs but high in proliferating SMCs. It was also highly induced by growth medium in vitro and in neointimal lesions in vivo. Inactivation of SIKs significantly attenuated vascular SMC proliferation and up-regulated p21CIP1 and p27KIP1. SIK inhibition also suppressed SMC migration and modulated actin polymerization. Importantly, we found that inhibition of SIKs reduced neointima formation and vascular inflammation in a femoral artery wire injury model. In mechanistic studies, we demonstrated that inactivation of SIKs mainly suppressed SMC proliferation by down-regulating AKT (protein kinase B) and PKA (protein kinase A)-CREB (cAMP response element-binding protein) signaling. CRTC3 (CREB-regulated transcriptional coactivator 3) signaling likely contributed to SIK inactivation-mediated antiproliferative effects.

Conclusions

These findings suggest that SIK3 may play a critical role in regulating SMC proliferation, migration, and arterial restenosis. This study provides insights into SIK inhibition as a potential therapeutic strategy for treating restenosis in patients with peripheral arterial disease.

Alternative Endograft Aortoiliac Reconstruction for Iliac Branch Endoprostheses

BACKGROUND

Endovascular treatment of complex common iliac artery (CIA) and internal iliac artery (IIA) aneurysms using iliac branch endoprostheses (IBE) has proven safe and effective. Instructions for use (IFU) require deployment of current IBE technology with the corresponding manufacturer's modular bifurcated aortic endograft. Concomitant aortoiliac occlusive disease, inadequate renal artery-iliac bifurcation length, and unfavorable aortic anatomy preclude on-label IBE deployment. This study aimed to evaluate the technical feasibility and safety of Alternative Endograft Aortoiliac Reconstruction (AEGAR) for branched endovascular treatment of complex iliac artery aneurysms.

METHODS

In 7 consecutive patients with CIA or IIA aneurysms, computed tomography angiography (CTA) and center-line reconstruction revealed aortoiliac anatomy incompatible with the current IBE IFU due to inadequate proximal CIA landing zone (n = 7), inadequate renal artery to iliac bifurcation length (n = 2), compromised aortic anatomy (n = 3), or short infrarenal neck <15 mm (n = 1), either alone or in combination. To overcome these restrictions and facilitate IBE deployment, aortoiliac reconstruction was performed using the Endologix AFX, Endologix Ovation limbs or the Medtronic Endurant II platforms (AEGAR technique). All internal iliac artery reconstructions and external iliac artery extensions were performed using the Gore VBX or Viabahn stent grafts. Technical success was defined as successful delivery of all endograft components without migration or endoleak.

RESULTS

The mean patient age was 69 years (range 52-82 years; 6 male). Four patients had bilateral CIA aneurysms and 3 patients had unilateral CIA aneurysms (mean diameter 4.3cm; range 2.2-7 cm). There were 13 IIA VBX stent grafts used for a total of 9 IIAs treated with IBE (bilateral IBE = 2 patients). The mean fluoroscopy time was 38.8 min (range 21.3-64.3 min) and the mean contrast volume was 168.5 mL (range 122-226 mL). Technical success was achieved in all patients and there were no perioperative complications. Mean hospital-stay was 2.2 days (range 1-3 days). Follow-up ranged from 82-957 days (mean = 487 days). At last follow-up, all patients were alive without cardiovascular morbidity; and CTA revealed stable or decreased aneurysm size, patent endografts, and no evidence of endoleak or migration.

CONCLUSIONS

The AEGAR technique can be used to safely and effectively overcome certain aortoiliac anatomic constraints that preclude use of current IBE technology. We encourage broader use of these alternative endografts in pertinent anatomic configurations.

Recovery of limb perfusion and function after hindlimb ischemia is impaired by arterial calcification

Medial artery calcification results from deposition of calcium hydroxyapatite crystals on elastin layers, and osteogenic changes in vascular smooth muscle cells. It is highly prevalent in patients with chronic kidney disease, diabetes, and peripheral artery disease (PAD), and when identified in lower extremity vessels, it is associated with increased amputation rates. This study aims to evaluate the effects of medial calcification on perfusion and functional recovery after hindlimb ischemia in rats. Medial artery calcification and acute limb ischemia were induced by vitamin D3 (VitD3 ) injection and femoral artery ligation in rats. VitD3 injection robustly induced calcification in the medial layer of femoral arteries in vivo. Laser Doppler perfusion imaging revealed that perfusion decreased and then partially recovered after hindlimb ischemia in vehicle-injected rats. In contrast, VitD3 -injected rats showed markedly impaired recovery of perfusion following limb ischemia. Accordingly, rats with medial calcification showed worse ischemia scores and delayed functional recovery compared with controls. Immunohistochemical and histological staining did not show differences in capillary density or muscle morphology between VitD3 - and vehicle-injected rats at 28 days after femoral artery ligation. The evaluation of cardiac and hemodynamic parameters showed that arterial stiffness was increased while cardiac function was preserved in VitD3 -injected rats. These findings suggest that medial calcification may contribute to impaired perfusion in PAD by altering vascular compliance, however, the specific mechanisms remain poorly understood. Reducing or slowing the progression of arterial calcification in patients with PAD may improve clinical outcomes.

Outcomes of bypass and endovascular interventions for advanced femoropopliteal disease in patients with premature peripheral artery disease

OBJECTIVE

Patients with premature peripheral artery disease (PAD), defined as age ≤50 years at presentation, have had poor outcomes with open and endovascular lower extremity revascularization. It is unclear whether either strategy is associated with better outcomes because comparative studies have been limited to case series in this patient population. The aim of the present study was to compare the outcomes of patients with premature PAD who had undergone bypass or endovascular revascularization for advanced femoropopliteal disease. Our hypothesis was that open bypass would provide superior long-term outcomes compared with endovascular intervention for patients with premature advanced femoropopliteal PAD.

METHODS

All the patients with premature PAD who had undergone isolated femoropopliteal lower extremity revascularization and included in the Vascular Quality Initiative infrainguinal bypass and peripheral vascular intervention files were reviewed from 2003 through 2019. Propensity score matching (1:1) was performed between patients who had undergone femoropopliteal bypass and endovascular interventions for isolated femoropopliteal Trans-Atlantic Classification System C or D lesions. The 1-year outcomes, including reintervention, patency, major amputation, and mortality, were analyzed.

RESULTS

Of the 2538 included patients, 902 had undergone isolated femoropopliteal endovascular intervention and 1636 had undergone femoropopliteal bypass. The endovascular intervention group were more likely to have diabetes (68.9% vs 54.0%; P < .001), coronary artery disease (31.0% vs 23.0%; P < .001), renal failure requiring dialysis (14.2% vs 7.2%; P < .001), and claudication (45.1% vs 36.6%; P < .001) compared with the bypass group. After propensity score matching, 466 patients were in each group with no significant differences in the baseline characteristics. Perioperative morbidity was higher with femoropopliteal bypass compared with endovascular intervention (12.0% vs 7.9%; P = .038); however, the rates of major amputation and mortality were not different. At 1 year, patients who had undergone femoropopliteal bypass were less likely to require reintervention (17.0% vs 25.2%; P = .012). However, no differences were found in major amputation (7.7% vs 7.9%; P = .928) or mortality (5.2% vs 5.2%; P = 1.00). Propensity score matching was also performed between femoropopliteal bypass with the great saphenous vein and isolated femoropopliteal endovascular interventions, and the outcomes were similar.

CONCLUSIONS

For patients with premature PAD and advanced femoropopliteal disease, bypass surgery decreased the reintervention rate at 1 year but was associated with increased perioperative morbidity and hospital length of stay compared with endovascular therapy. No differences were found in major amputation or mortality between the two strategies.

Emergent percutaneous chimney endovascular aortic repair of a secondary aortoenteric fistula in the setting of a solitary kidney

Secondary aortoenteric fistula is a potentially lethal complication after aortic surgery. Traditional treatment consists of open graft excision with extra-anatomic bypass or in situ reconstruction. Patients who present in extremis, however, are generally poor candidates for re-do open aortic surgery. Endovascular repair has emerged as an alternative treatment modality for patients who would otherwise be unable to tolerate an extended operation. We report here a case of urgent endovascular repair of a juxtarenal secondary aortoenteric fistula via endovascular aneurysm repair with a renal artery chimney in a patient with a solitary kidney who presented in hemorrhagic and septic shock.