Misty D. Humphries

Outcomes of covered versus bare-metal balloon-expandable stents for aortoiliac occlusive disease.

OBJECTIVE Randomized trials and retrospective data suggest that covered balloon-expandable (CBE) stents have better short-term patency compared with balloon-expandable bare-metal stents (BMSs) in the treatment of iliac artery disease. This study evaluated midterm outcomes of BMSs vs CBE stents placed in the common iliac artery (CIA) for aortoiliac occlusive disease. METHODS All endovascular interventions for symptomatic peripheral arterial occlusive disease performed at a single institution from 2006 to 2012 were reviewed. Patients undergoing stent placement in the CIA segment were included in the analysis. Demographic data, TransAtlantic Inter-Society Consensus (TASC) classification, stent type, patency, and limb reinterventions were compared. RESULTS For treatment of de novo distal aorta or CIA stenosis, 254 procedures were performed in 162 patients. BMSs were used in 190 arteries; CBE stents were used in 64 arteries. There was no difference in age, gender, or TASC classification between the two groups. Mean follow-up was 22 ± 16 months. Primary patency, assisted patency, and secondary patency were significantly better in the BMS group. CIAs treated with covered stents were more likely at 1 year or longer to require repeated intervention (hazard ratio, 2.5; 95% confidence interval, 1.2-5.3; P = .009). TASC classification did not predict need for reintervention in either group. Multivariate analysis revealed dual antiplatelet therapy to be the only other factor to affect patency during long-term follow-up. CONCLUSIONS In this study, BMSs had significantly better patency compared with CBE stents for treatment of aortoiliac occlusive disease. A randomized trial comparing patency as well as restenosis rates with long-term follow-up is needed to determine if there is any benefit from use of covered stents in the aortoiliac segment.

The contemporary management of renal artery aneurysms

BACKGROUND Renal artery aneurysms (RAAs) are rare, with little known about their natural history and growth rate or their optimal management. The specific objectives of this study were to (1) define the clinical features of RAAs, including the precise growth rate and risk of rupture, (2) examine the current management and outcomes of RAA treatment using existing guidelines, and (3) examine the appropriateness of current criteria for repair of asymptomatic RAAs. METHODS A standardized, multi-institutional approach was used to evaluate patients with RAAs at institutions from all regions of the United States. Patient demographics, aneurysm characteristics, aneurysm imaging, conservative and operative management, postoperative complications, and follow-up data were collected. RESULTS A total of 865 RAAs in 760 patients were identified at 16 institutions. Of these, 75% were asymptomatic; symptomatic patients had difficult-to-control hypertension (10%), flank pain (6%), hematuria (4%), and abdominal pain (2%). The RAAs had a mean maximum diameter of 1.5 ± 0.1 cm. Most were unilateral (96%), on the right side (61%), saccular (87%), and calcified (56%). Elective repair was performed in 213 patients with 241 RAAs, usually for symptoms or size >2 cm; the remaining 547 patients with 624 RAAs were observed. Major operative complications occurred in 10%, including multisystem organ failure, myocardial infarction, and renal failure requiring dialysis. RAA repair for difficult-to-control hypertension cured 32% of patients and improved it in 26%. Three patients had ruptured RAA; all were transferred from other hospitals and underwent emergency repair, with no deaths. Conservatively treated patients were monitored for a mean of 49 months, with no acute complications. Aneurysm growth rate was 0.086 cm/y, with no difference between calcified and noncalcified aneurysms. CONCLUSIONS This large, contemporary, multi-institutional study demonstrated that asymptomatic RAAs rarely rupture (even when >2 cm), growth rate is 0.086 ± 0.08 cm/y, and calcification does not protect against enlargement. RAA open repair is associated with significant minor morbidity, but rarely a major morbidity or mortality. Aneurysm repair cured or improved hypertension in >50% of patients whose RAA was identified during the workup for difficult-to-control hypertension.

Early duplex scanning after infrainguinal endovascular therapy

OBJECTIVES Duplex ultrasound scanning (DUS) has benefit for intraoperative and subsequent evaluation of surgical bypasses in the lower extremities. The utility of DUS after endovascular revascularizations is not established. This study was performed to evaluate whether DUS findings after infrainguinal endovascular interventions for critical limb ischemia (CLI) were predictive of need for reintervention or amputation. METHODS To identify the study cohort, peripheral interventions for CLI (Rutherford grades 4, 5, 6) over a 24-month period (2006-2007) were reviewed. DUS findings were considered indicative of hemodynamic stenosis if the peak systolic velocity (PSV) was ≥ 180 cm/s or the PSV velocity ratio was ≥ 2.0. Demographic, clinical, procedural, and outcomes were examined. SVS and TASC II classifications and reporting standards were used. Arteriograms were reviewed and treated segments were categorized as patent (<30% residual stenosis) or abnormal (≥ 30% residual stenosis). RESULTS There were 122 infrainguinal interventions for CLI in 113 patients (53% male; mean age 71 years). Risk factors included diabetes: 61%; renal failure: 20%; and smoking (within 1 year): 40%. DUS was performed within 30 days of the index procedure in 90 cases. Fifty patients had an abnormal early duplex and 40 patients had a normal duplex. In patients with a normal duplex ultrasound the amputation rate was 5% vs 20% in the group with an abnormal duplex (P = .04). Primary patency was 56% in the normal duplex group and 46% in the abnormal duplex group (P = .18). Early duplex ultrasound was able to identify a residual stenosis not seen on completion angiography in 56% of cases. CONCLUSIONS Duplex scanning detects residual stenosis missed with conventional angiography after infrainguinal interventions. An abnormal DUS in the first 30 days after an intervention is associated with an increased risk of amputation. This suggests a possible role for intraprocedural DUS, as well as routine postprocedure DUS, close clinical follow-up, and consideration of reintervention for residual abnormalities in patients treated for CLI.

Amputation Risk in Patients with Diabetes Mellitus and Peripheral Artery Disease Using Statewide Data.

BACKGROUND Conflicting data exist regarding changes in amputation rates in patients with ulcers because of diabetes mellitus (DM) and peripheral artery disease (PAD). This study focuses on how population-based amputation rates are changing in the current treatment era. METHODS Using the California Office of Statewide Health Planning and Development Patient Discharge database, all patients who underwent major nontraumatic lower extremity (LE) amputation in 2005 through 2011 were identified. Age-adjusted population-based amputation risk was determined by year. Gender and age trends in amputation risk were estimated separately for diabetes-related amputations and PAD-related amputations, treating all California residents as the population at risk. RESULTS From 2005 to 2011, 32,025 qualifying amputations were performed in California. Of these, 11,896 were DM-associated (n = 1,095), PAD-associated (n = 4,335), or associated with both conditions (n = 6,466). PAD-associated amputation rates and combined PAD/DM-associated amputation rates have changed little since 2009 after decreasing substantially over the prior 5 years, but DM-associated amputation rates have continuously increased since 2005. California residents older than the age of 80 years had the most dramatic decrease in PAD-associated amputation rates from 2005 to 2011 (i.e., from 317 to 175 per million Californians). Men with PAD/DM had amputation rate 1.5 times higher than those of patients with PAD alone and 5 times higher than rates of DM patients. In women the difference between patient with PAD and PAD/DM was not seen; however, these rates were 2.5 times higher than patients with DM alone. CONCLUSIONS Preventable amputations associated with high-risk diseases are no longer decreasing despite continuing advances in care and education. Octogenarians with PAD represent the highest risk group for amputation, but DM-associated amputations have increased since 2005. Further research to understand treatment pathways for patient with LE wounds may shed light on pathways for amputation prevention in the future.

Therapeutic Anticoagulation for Isolated Calf Deep Vein Thrombosis

IMPORTANCE Deep vein thrombosis (DVT) isolated to the calf veins (distal to the popliteal vein) is frequently detected with duplex ultrasonography and may result in proximal thrombosis or pulmonary embolism (PE). OBJECTIVE To evaluate whether therapeutic anticoagulation is associated with a decreased risk for proximal DVT or PE after diagnosis of an isolated calf DVT. DESIGN, SETTING, AND PARTICIPANTS All adult patients with ultrasonographic detection of an isolated calf DVT from January 1, 2010, to December 31, 2013, at the Vascular Laboratory of the University of California, Davis, Medical Center were included. Patients already receiving therapeutic anticoagulation and those with a chronic calf DVT, a contraindication to anticoagulation, prior venous thromboembolism within 180 days, or diagnosis of a PE suspected at the time of calf DVT diagnosis were excluded. Data were analyzed from August 18, 2015, to February 14, 2016. EXPOSURES Intention to administer therapeutic anticoagulation. MAIN OUTCOMES AND MEASURES Proximal DVT or PE within 180 days of the diagnosis of the isolated calf DVT. RESULTS From 14 056 lower-extremity venous duplex studies, we identified 697 patients with an isolated calf DVT and excluded 313 of these. The remaining 384 patients were available for analysis (222 men [57.8%]; 162 women [42.2%]; mean [SD] age, 60 [16] years). The calf DVT involved an axial vein (anterior tibial, posterior tibial, or peroneal) in 243 patients (63.2%) and a muscular branch (soleus or gastrocnemius) in 215 (56.0%). Physicians attempted to administer therapeutic anticoagulation in 243 patients (63.3%), leaving 141 control participants. Proximal DVT occurred in 7 controls (5.0%) and 4 anticoagulation recipients (1.6%); PE, in 6 controls (4.3%) and 4 anticoagulation recipients (1.6%). Therapeutic anticoagulation was associated with a decreased risk for proximal DVT or PE at 180 days (odds ratio [OR], 0.34; 95% CI, 0.14-0.83) but an increased risk for bleeding (OR, 4.35; 95% CI, 1.27-14.9), findings that persisted after adjustment for confounding factors (ORs, 0.33 [95% CI, 0.12-0.87] and 4.87 [95% CI, 1.37-17.3], respectively) and sensitivity analyses. CONCLUSIONS AND RELEVANCE Rates of proximal DVT or PE are low after isolated calf DVT. Therapeutic anticoagulation is associated with a reduction of these outcomes but an increase in bleeding.

The current management of isolated degenerative femoral artery aneurysms is too aggressive for their natural history

BACKGROUND Previous studies have combined anastomotic, catheter-induced, and atherosclerotic isolated femoral artery aneurysms (FAAs) to achieve adequate numbers for analysis and have recommended repair of asymptomatic FAAs with diameters ≥2.5 cm and all symptomatic FAAs. This study evaluated the contemporary management of isolated FAAs. METHODS Patients with FAAs were evaluated using a standardized, prospectively maintained database by a research consortium. RESULTS From 2002 to 2012, 236 FAAs were identified in 182 patients (mean age, 72 years; male-to-female ratio, 16:1) at eight institutions. The mean nonoperative mean diameter was 2.8 ± 0.7 cm, and the operative diameter was 3.3 ± 1.5 cm. FAA location was the common femoral artery in 191, superficial femoral artery (SFA) in 34, and profunda femoris artery in 11. Synchronous aneurysms (mean, 1.7 per patient) occurred in the aorta (n = 113), in the iliac (n = 109), popliteal (n = 86), and hypogastric (n = 56) arteries, and in the contralateral common femoral artery (n = 34), SFA (n = 9), and profunda femoris artery (n = 2). Of the aneurysms repaired, 66% were asymptomatic; other indications for repair were claudication (18%), local pain (8%), nerve compression (3%), rupture (2%), acute thrombosis (1%), and rest pain (0.5%). Acute aneurysm-related complications (rupture, thrombosis, embolus) were associated (P < .05) with FAA diameter >4 cm and intraluminal thrombus, but not location. Mean diameter of asymptomatic aneurysms that developed acute complications was 5.7 ± 1.3 cm for rupture, 4 ± 1.1 cm for thrombosis, and 3.5 cm for embolus. Repair was by interposition or bypass graft in 177 FAAs and by endovascular repair in three SFA aneurysms. Two perioperative deaths, of myocardial infarction and multisystem organ failure, occurred at 30 days. Operative complications included wound infection (6%), seroma (3%), and bleeding (2%). No amputations occurred through 5 years in the operative or nonoperative groups. Survival in operated-on patients was 99% (n = 138) at 3 months, 92% at 1 year, and 81% (n = 20) at 5 years. CONCLUSIONS This largest study of isolated FAAs demonstrates that (1) acute complications did not occur in FAAs ≤3.5 cm, repair criteria of asymptomatic FAAs should be changed to >3.5 cm, and chronic intraluminal thrombus should reduce the threshold for repair, and that (2) current indications for symptomatic FAA repair result in low morbidity and should remain unchanged.

Asymptomatic Bilateral External Iliac Vein Aneurysms in a Young Athlete: Case Report and Literature Review:

Iliac vein aneurysms are an exceedingly uncommon problem faced by vascular specialists. We report a case of a healthy 32 year old woman who had large asymptomatic bilateral external iliac vein aneurysms found incidentally on CT scan. They may present with thromboembolism, spontaneous rupture, or they may be asymptomatic. In evaluating these aneurysms, it is important to obtain volumetric imaging data that can be rendered in 3-dimensions and reconstructed in multiple planes. With our patient, it was the multiplanar reconstructions that best demonstrated the fusiform morphology of the aneurysms. Treatment for asymptomatic external iliac veins is controversial.

Gender and Outcomes of Carotid Artery Interventions

The benefits of carotid artery revascularization in women have been debated since the publication of large randomized clinical trials comparing carotid endarterectomy (CEA) to medical therapy. Institutional series have historically had an underrepresentation of women and/or have lacked power for adequate analysis. Recent evidence from large databases reveals possible gender-based differences in outcomes of carotid artery stenting versus CEA. In this review, we evaluated clinical articles from 1991 to 2012, using Pubmed and Web of Science, which addressed gender and outcomes of carotid artery revascularization procedures. Our goal was to determine whether gender is associated with adverse outcomes following carotid artery interventions in patients with carotid artery disease.

Multidisciplinary Management of Blunt Renal Artery Injury with Endovascular Therapy in the Setting of Polytrauma: A Case Report and Review of the Literature

BACKGROUND Injury to the renal artery is a rare but serious concern in patients suffering blunt trauma. Complications of renovascular injury include prolonged hospitalization, kidney loss, and death. There remains considerable controversy regarding the optimal treatment of blunt renal artery injury. METHODS We describe the management of a 39-year-old woman following blunt polytrauma who underwent a multidisciplinary collaborative procedure with open splenectomy and endovascular repair of an occluded renal artery. A literature review of the past 25 years follows including all publications describing endovascular treatment for blunt renal artery injury. RESULTS The literature search identified 27 patients with blunt renal artery injury treated by endovascular means. All patients were treated with angioplasty and stenting; none were treated with angioplasty alone. One patient (4%) required nephrectomy for hypertension and 89% of patients were reported to be in good condition at their last contact with the healthcare system. CONCLUSIONS The optimal treatment of blunt injury to the renal artery is unknown, but endovascular therapy is a feasible and reasonable choice. Further study is warranted to delineate the appropriate role for endovascular treatment as a component of a multidisciplinary approach to the care of trauma patients with blunt renal artery injury.

Technical and Early Outcomes Using Ultrasound-Guided Reentry for Chronic Total Occlusions

BACKGROUND Subintimal angioplasty is a common treatment for chronic total occlusions (CTOs) in the iliac and infrainguinal arteries. Although technical success has been described using intravascular ultrasound-guided reentry devices (IVUS-RED), outcomes are still not well defined. This report describes the technical aspects and longitudinal follow-up after intravascular ultrasound-guided reentry of iliac and infrainguinal CTOs. METHODS A retrospective review was performed of 20 patients with lower extremity CTO treated with IVUS-RED from 2011 to 2013. A matched cohort of patients who underwent lower extremity interventions without the use of IVUS-RED was also identified. Procedural success, patency estimates, ankle-brachial indices (ABIs), complications, and limb salvage were analyzed. RESULTS Twenty patients (mean age, 69 ± 13 years), including 11 men and 9 women, underwent attempted IVUS-RED-guided recanalization. Median follow-up was 4.3 months (range, 0.4-24). Eleven patients presented with critical limb ischemia (CLI), and 9 presented with claudication. Technical success was achieved in 18 (90%) patients. Ten common iliac arteries, 3 external iliac arteries, and 5 superficial femoral arteries (SFA) were treated. No intraoperative complications resulted from device use. After procedure, ABIs significantly increased (0.5-0.9; P < 0.01) in the 13 patients with follow-up. Primary patency for the entire cohort was 62% at 12 months. No patient treated for claudication required reintervention, whereas 3 (27%) of those treated for CLI required repeat interventions. During follow-up, 2 patients died unrelated to the procedure, 1 patient required an amputation, and 1 patient eventually required open revascularization. When the IVUS-RED group was compared with a cohort matched on Trans-Atlantic Inter-Society Consensus and age, no difference was found in runoff scores and patency between the 2 groups during follow-up (P > 0.05). CONCLUSIONS Recanalization of CTO using IVUS-RED is safe and effective. Use of IVUS-RED does not adversely impact outcomes in conjunction with other endovascular techniques. Early follow-up demonstrates acceptable patency, especially in patients with claudication, and freedom from reintervention.