Predicting Factors Associated with Postoperative Hypotension following Carotid Artery Stenting.

BACKGROUND: Prolonged hemodynamic instability after carotid artery stenting (CAS) has been associated with increased incidence of stroke and other major adverse events. The objective of this study is to determine the factors associated with hypotension following CAS. In particular, this study evaluates whether involvement of the carotid bifurcation/bulb and degree of calcification can predict postoperative hypotension. METHODS: A retrospective review of 90 CASs performed in 88 patients at a single tertiary center was completed. In patients with proximal internal carotid stenosis involving the carotid bifurcation, the extent of bifurcation/bulb calcification on preoperative computed tomography angiography was assessed using a scoring system. Calcium scores were assigned based on the percent of circumferential calcification of carotid bifurcation as follows: grade 1, <10%; grade 2, 10-50%; grade 3, 50-90%; and grade 4, >90%. Perioperative factors associated with prolonged postoperative hypotension requiring vasopressor infusion were analyzed. RESULTS: Overall, postoperative hypotension requiring vasopressors occurred in 26 (28.9%) of CAS. There were no differences in baseline demographics, comorbidities, or CAS indication between patients who required postoperative vasopressors for hypotension and those who did not. The majority of patients (64.4%) were on 2 or more antihypertensive medications preoperatively. Stenosis involved carotid bifurcation in 64 (71.1%) cases. Of these, 27 (42.2%) were grade 1, 19 (29.7%) were grade 2, 10 (15.6%) were grade 3, and 8 (12.5%) were grade 4 based on our calcium scoring system. On risk-adjusted analysis, carotid bifurcation/bulb involvement (adjusted odds ratio [aOR] 4.5, 95% confidence interval [CI] 1.1-18.5) and preoperative regimen of 2 or more antihypertensives (aOR 4.2, 95% CI 1.1-16.0) were independent predictors of hypotension requiring vasopressors following CAS. Among patients with carotid bifurcation involvement, severity of calcium score was not a significant predictor of postoperative hypotension. CONCLUSIONS: CAS for carotid stenosis involving the carotid bifurcation/bulb is associated with a higher risk for postoperative hypotension requiring vasopressors. Patients with preoperative hypertension requiring 2 or more antihypertensive medications are also at increased risk. However, severity of carotid bifurcation calcification is not a significant predictor of need for postoperative vasopressors.

Determinants of outcome after endovascular therapy for critical limb ischemia with tissue loss.

BACKGROUND: In this study we examine outcomes of endovascular therapy for critical limb ischemia with tissue loss and identify risk factors for failure of endovascular therapy across a panel of outcome metrics. METHODS: A retrospective review (2006-2010) of patients undergoing endovascular therapy for critical limb ischemia with tissue loss provided data for multivariate models of overall survival, amputation-free survival, limb salvage (LS), and wound healing. RESULTS: One hundred six patients underwent endovascular therapy for Rutherford class 5 (88%) or class 6 (12%) ischemia with ulceration and/or gangrene of the heel (15%), forefoot (16%), toe(s) (43%), calf/ankle (11%), or multiple locations (15%). Sustained limb salvage at 1 year was 87%. One-year overall survival and amputation-free survival were 65% and 49%, respectively. Multivariate regression models identified independent risk factors for reduced primary patency: Rutherford 6 ischemia (P = 0.008; HR 4.7 [95% confidence interval 1.5-14.8]) and infrapopliteal intervention (P = 0.03; HR 2.58 [95% CI 1.08-6.14]). Rutherford class 6 ischemia was independently associated with reduced assisted patency (P = 0.004; HR 5.39 [95% CI 1.74-16.73]). Wound healing was adversely affected by diabetes (P = 0.02; HR 7.0 [95% CI 1.4-36.2]), continued smoking (P = 0.04; HR 5.3 [95% CI 1.1-26.3]), and patency loss (P = 0.04; HR 4.8 [95% CI 1.1-22.30]). Rutherford class 6 ischemia was independently associated with reduced limb salvage (P < 0.0001; HR 35.1 [95% CI 5.4-231.2]) and amputation-free survival (P = 0.007; HR 3.61 [95% CI 1.4-9.18]), in addition to COPD (P = 0.01; 3.58 [95% 1.28-9.55]). Independent predictors of poor overall survival included end-stage renal disease (P = 0.03; HR 2.99 [95% CI 1.1-8.05]), history of angina (P = 0.02; HR 5.08 [95% CI 1.28-20.29]), and COPD (P = 0.001; HR 3.77 [95% CI 1.76-8.34]). CONCLUSIONS: Both increasing severity of tissue loss as well as the presence of severe medical comorbidities are associated with poorer outcomes of endovascular therapy in these patients. Although sustained limb salvage in patients with tissue loss may be achieved with endovascular therapy, this is due to poor overall survival and a competing mortality hazard.

The Comprehensive Risk Assessment for Bypass (CRAB) facilitates efficient perioperative risk assessment for patients with critical limb ischemia.

OBJECTIVE: Specific perioperative risk assessment models have been developed for bariatric, pancreatic, and colorectal surgery. A similar instrument, specific for patients with critical limb ischemia (CLI), could improve patient-centered clinical decision making. We describe a novel tool to predict 30-day major morbidity and mortality (M&M) after bypass surgery for CLI. METHODS: Data for 4985 individuals from the 2007 to 2009 National Surgical Quality Improvement Program were used to develop and internally validate the model. Outcome measures included mortality, major morbidity, and a composite end point (M&M). M&M included mortality and the most severe postoperative morbidities that were highly associated with death (eg, sepsis and major cardiopulmonary complications). More than 30 preoperative factors were tested for association with 30-day mortality, major morbidity, and M&M. Significant predictors in multivariate models were assigned integer values (points), which were added to calculate a patient's Comprehensive Risk Assessment For Bypass (CRAB) score. Performance was assessed (C-index) across all outcome measures and compared with other general tools (American Society of Anesthesiologists class, Surgical Risk Scale) and existing CLI-specific survival prediction models (Finnvasc score, Edifoligide for the Prevention of Infrainguinal Vein Graft Failure [PREVENT III] score) on a distinct validation sample (n = 1620). RESULTS: In the derivation data set (n = 3275), the 30-day mortality rate was 2.9%. The rate of any major morbidity was 19.1%. The composite end point M&M occurred in 10.1%. Significant predictors of M&M by multivariate analysis included age >75 years, prior amputation or revascularization, tissue loss, dialysis dependence, severe cardiac disease, emergency operation, and functional dependence. Applied to a distinct validation sample of 1620 patients, higher CRAB scores were significantly associated with higher rates of mortality, all major morbidities, and M&M (P < .0001). Comparison with other models by assessment of area under the receiver-operating characteristic curve revealed the CRAB was a more accurate predictor of mortality, all major morbidity, and M&M. CONCLUSIONS: The CRAB is a CLI-specific, risk assessment instrument derived from multi-institutional American College of Surgeons-National Surgical Quality Improvement Program surgical outcomes data that out-performs existing prognostic risk indices in the prediction of clinically significant adverse events after bypass surgery. Use of the CRAB as a risk assessment tool provides an evidence basis for patient-centered clinical decision making and may have a role in identifying patients at higher risk for surgical revascularization in whom an endovascular approach is preferable.

Risk factors for early failure after peripheral endovascular intervention: application of a reliability engineering approach.

BACKGROUND: We apply an innovative and novel analytic approach, based on reliability engineering (RE) principles frequently used to characterize the behavior of manufactured products, to examine outcomes after peripheral endovascular intervention. We hypothesized that this would allow for improved prediction of outcome after peripheral endovascular intervention, specifically with regard to identification of risk factors for early failure. METHODS: Patients undergoing infrainguinal endovascular intervention for chronic lower-extremity ischemia from 2005 to 2010 were identified in a prospectively maintained database. The primary outcome of failure was defined as patency loss detected by duplex ultrasonography, with or without clinical failure. Analysis included univariate and multivariate Cox regression models, as well as RE-based analysis including product life-cycle models and Weibull failure plots. Early failures were distinguished using the RE principle of "basic rating life," and multivariate models identified independent risk factors for early failure. RESULTS: From 2005 to 2010, 434 primary endovascular peripheral interventions were performed for claudication (51.8%), rest pain (16.8%), or tissue loss (31.3%). Fifty-five percent of patients were aged ≥75 years; 57% were men. Failure was noted after 159 (36.6%) interventions during a mean follow-up of 18 months (range, 0-71 months). Using multivariate (Cox) regression analysis, rest pain and tissue loss were independent predictors of patency loss, with hazard ratios of 2.5 (95% confidence interval, 1.6-4.1; P < 0.001) and 3.2 (95% confidence interval, 2.0-5.2, P < 0.001), respectively. The distribution of failure times for both claudication and critical limb ischemia fit distinct Weibull plots, with different characteristics: interventions for claudication demonstrated an increasing failure rate (ß = 1.22, θ = 13.46, mean time to failure = 12.603 months, index of fit = 0.99037, R(2) = 0.98084), whereas interventions for critical limb ischemia demonstrated a decreasing failure rate, suggesting the predominance of early failures (ß = 0.7395, θ = 6.8, mean time to failure = 8.2, index of fit = 0.99391, R(2) = 0.98786). By 3.1 months, 10% of interventions failed. This point (90% reliability) was identified as the basic rating life. Using multivariate analysis of failure data, independent predictors of early failure (before 3.1 months) included tissue loss, long lesion length, chronic total occlusions, heart failure, and end-stage renal disease. CONCLUSIONS: Application of a RE framework to the assessment of clinical outcomes after peripheral interventions is feasible, and potentially more informative than traditional techniques. Conceptualization of interventions as "products" permits application of product life-cycle models that allow for empiric definition of "early failure" may facilitate comparative effectiveness analysis and enable the development of individualized surveillance programs after endovascular interventions.

Adventitial cystic disease of the femoral vein in a 5-year-old boy mimicking deep venous thrombosis.

Adventitial cystic disease of the vein is a rare vascular anomaly with 32 reported cases. A 5-year-old boy initially presented with painless leg swelling. He was misdiagnosed with deep vein thrombosis and treated with 3 months of warfarin. When swelling failed to improve, a magnetic resonance venogram showed a mural cystic lesion of the left common femoral vein. In the operating room, the cyst was excised, relieving the obstructive effect and restoring flow. The swelling resolved within days. This is the first reported case of adventitial cystic disease of the vein occurring in a pediatric patient.

Midterm outcomes after treatment of type II endoleaks associated with aneurysm sac expansion.

PURPOSE: To examine the outcomes following interventions for type II endoleaks in patients with aneurysm sac expansion after endovascular aneurysm repair (EVAR). METHODS: A retrospective review was conducted of all patients who underwent treatment for type II endoleak from July 2001 to September 2010 in a single center. In this time period, 29 (4.7%) patients (22 men; mean age 78.6 years, range 54-87) were identified as having a type II endoleak and enlargement of the aneurysm sac, meeting the criterion for treatment. All patients had at least one attempted percutaneous intervention. Patients were followed both clinically and radiographically, with computed tomographic angiography every 3 to 12 months, over a follow-up period that ranged from 1 to 10 years (mean 3.5). RESULTS: Forty-eight interventions were performed on the 29 patients. Of these, 15 (56%) patients underwent multiple (2-4) procedures. Of the 11 endoleaks with an isolated inferior mesenteric artery identified as the source, initial success for transarterial embolization at 2 years was 72%, with 2 of the failures having successful secondary interventions. For the 18 endoleaks with a lumbar source, the success of the initial intervention was 17% at 2 years; repeated embolization attempts produced a 40% secondary success rate. Seven (24%) patients had continued endoleak despite multiple treatment attempts; 3 ultimately required elective aortic graft explantation. There were no ruptures or deaths during the study period. In a comparison of type II endoleak patients who had stable aneurysm sacs and those who had persistent sac expansion, the only significant differences in preoperative anatomical characteristics were a lower prevalence of mural thrombus (p = 0.036) and longer right iliac arteries (p = 0.012) in the group with sac expansion. Independent predictors of type II endoleak were mural thrombus (p<0.001), patent lumbar arteries (p = 0.004), aneurysm length (p = 0.011), and iliac artery length (p = 0.004). CONCLUSION: This study demonstrates that most patients require multiple reinterventions to treat type II endoleaks; specifically, lumbar artery embolization carries a low midterm success rate.

An interdisciplinary approach to the prevention and treatment of groin wound complications after lower extremity revascularization.

BACKGROUND: If not effectively treated, groin wound infections following lower extremity revascularization (LER) may result in graft or limb loss. METHODS: A retrospective review was performed of all patients who underwent muscle flap transposition by a single surgeon after LER between 2006 and 2010. RESULTS: Twenty-nine muscle transposition flaps were performed in 24 patients (21 sartorius, 6 rectus femoris, and 2 gracilis). Nineteen were for treatment of groin wound infections, two for treatment of lymphocele, one for coverage of exposed graft in the setting of pyoderma gangrenosum, and seven for infection prophylaxis. Two graft losses followed flap placement. The limb loss rate was 4%. When performed for therapeutic purposes, graft salvage rates were 100% for autogenous and 92% for synthetic grafts. CONCLUSIONS: Muscle transposition flaps are an effective means of graft salvage in the setting of groin wound complications following LER and should be considered for infection prophylaxis in high-risk patients.

The use of gadolinium for arterial interventions.

BACKGROUND: Gadolinium (Gd) has been traditionally used as a non-nephrotoxic alternative to iodinated contrast for digital subtraction angiography (DSA) in patients with chronic renal insufficiency. However, its use has been questioned on the basis of reports of nephrotoxicity and its recent association with nephrogenic systemic fibrosis (NSF), a potentially lethal complication. Recently available data are conflicting with respect to the true safety profile of intra-arterial Gd. The purpose of this study was to examine the risk of contrast nephropathy and NSF after Gd exposure in a large population of azotemic patients undergoing DSA. METHODS: A comprehensive database encompassing data on all patients who underwent DSA between June 2003 and December 2007 at the New York Presbyterian Hospital was retrospectively reviewed. Patients receiving Gd either alone or in combination with iodinated contrast during DSA were identified and further analyzed. Acute renal failure (ARF) was defined as an elevation in serum creatinine (Cr) by >0.5 mg/dL within 48 hours of exposure. Clinical follow-up was conducted through chart reviewing as well as telephonic interviews with patients and their primary care physicians. RESULTS: A total of 153 patients underwent 179 exposures to Gd either alone (33%) or in combination (67%) with iodinated contrast. Mean follow-up duration was 27.1 months. The mean Cr level was 1.94 ± 0.78 mg/dL and 1.96 ± 1.1 mg/dL before and after DSA, respectively. There were 20 (11.2%) instances of ARF. The mean Cr level before DSA was higher in patients who developed ARF versus those in the non-ARF group (2.7 ± 1.1 mg/dL vs. 1.9 ± 0.7 mg/dL, p = 0.004). In the ARF group, 12 patients had a return to baseline renal function, four experienced irreversible renal deterioration, and four needed dialysis (4.5% incidence of irreversible renal failure). There were 19 deaths at the time of this study (12.4%). The highest risk for the development of ARF after Gd exposure occurred in patients with Cr levels of >3.0 mg/dL before DSA and in those receiving >0.4 mmol/kg of Gd. For patients who received iodinated contrast in combination with Gd, there was a trend toward a higher risk for developing ARF as compared with those receiving only Gd. Finally, there were no instances of NSF identified in any of the patients who received intra-arterial Gd. CONCLUSIONS: Although Gd has the potential to cause kidney injury similar to iodinated contrast, the risk of irreversible renal failure and the requirement for dialysis is low. Life- or limb-threatening interventions should not be avoided in this patient cohort because of preexisting elevations in Cr. These data should help guide the use of Gd in patients with chronic renal insufficiency.

Effectiveness and Safety of Biodegradable Calcium Sulfate Antibiotic Beads as Adjuvant Therapy in Vascular Graft Infections.

This is a retrospective cohort study evaluating the safety and effectiveness of biodegradable calcium sulfate antibiotic beads in vascular graft infections compared with standard of care. No differences in acute kidney injury or hypercalcemia were observed between the cohorts. Recurrence of infection did not occur in the 13-patient bead cohort compared with 14 patients who had recurrence in the 45-patient nonbead cohort with a number needed to treat of 4.0.

Endovascular aneurysm repair in nonagenarians is safe and effective.

OBJECTIVES: Advanced age is a significant risk factor that has traditionally steered patients away from open aneurysm repair and toward expectant management. Today, however, the reduced morbidity and mortality of aortic stent grafting has created a new opportunity for aneurysm repair in patients previously considered too high a risk for open surgery. Here we report our experience with endovascular aneurysm repair (EVAR) in nonagenarians. METHODS: Retrospective chart review identified all patients>90-years-old undergoing EVAR over a 9-year period at our institution. Collected data included preoperative comorbidities, perioperative complications, endoleaks, reinterventions, and long-term survival. RESULTS: 24 patients underwent EVAR. The mean age was 91.5 years (range 90-94) among 15 (63%) males and 9 (37%) females. Mean abdominal aortic aneurysm diameter was 6.3±1.1 cm. Eight patients (33%) were symptomatic (pain or tenderness). There were no ruptures. Fourteen patients (58%) had general anesthesia while 10 (42%) had local or regional anesthesia. Mean postoperative length of stay was 3.2±2.4 days (2.8±1.9 days for asymptomatic vs 4.1±3.2 days for symptomatic, P=.29). There was one perioperative mortality (4.2%). There were two local groin seromas (8.3%) and six systemic complications (25%). One patient required reintervention for endoleak (4.2%). There were no aneurysm related deaths beyond the 30-day postoperative period. Mean survival beyond 30 days was 29.7±18.0 months for patients expiring during follow-up. Cumulative estimated 12, 24, and 36-month survival rates were 83%, 64%, and 50%, respectively. Linear regression analysis demonstrated an inverse relationship between the number of preoperative comorbidities and postoperative survival in our cohort (R2=0.701), with significantly decreased survival noted for patients presenting with >5 comorbidities. Those still alive in follow-up have a mean survival of 36.1±16.0 months. CONCLUSION: This is the largest reported EVAR series in nonagenarians. Despite their advanced age, these patients benefit from EVAR with low morbidity, low mortality, and mean survival exceeding 2.4 years. Survival appears best in those patients with ≤5 comorbidities. With or without symptoms, patients over the age of 90 should be considered for EVAR.

Ruptured persistent sciatic artery aneurysm managed by endovascular embolization.

Persistent sciatic artery (PSA) is a rare vascular anomaly present in 0.025% to 0.05% of the population. They are particularly prone to aneurysmal degeneration, potentially leading to distal ischemia, sciatic neuropathy, or rarely rupture. Here, we describe a case of a ruptured PSA aneurysm managed by endovascular embolization. A 70-year-old man initially presented with acute left lower extremity ischemia. He was found to have a popliteal embolus originating from a complete persistent sciatic artery aneurysm. He underwent thrombolysis followed by a femoropopliteal bypass and ligation of the proximal popliteal artery to exclude the PSA. Four weeks later he re-presented with severe pain, a pulsatile buttock mass, and anemia in the setting of hemodynamic instability. A ruptured PSA aneurysm was confirmed by computed tomography angiography (CTA). This was managed emergently by endovascular exclusion of the inflow and outflow vessels using Amplatzer vascular plugs. His postoperative course was complicated by both a foot drop, likely secondary to sciatic nerve ischemia, and a buttock abscess. To our knowledge, this is the first report detailing the endovascular management of a ruptured PSA aneurysm. The etiology, management, and complications associated with the treatment of this rare vascular entity are discussed.

Flow loading induces macrophage antioxidative gene expression in experimental aneurysms.

OBJECTIVE: Reactive oxygen species may act as proinflammatory mediators in abdominal aortic aneurysm (AAA) disease. Flow loading increases antioxidative enzyme expression and limits reactive oxygen species production in vascular smooth muscle cells in vitro, limits experimental AAA enlargement in rodent models, and is indirectly associated with reduced clinical AAA risk. We attempted to determine the mechanism or mechanisms by which flow loading limits AAA enlargement. METHODS AND RESULTS: Rodent AAAs were flow loaded via femoral arteriovenous fistula creation. Aortic wall shear stress and relative wall strain were significantly higher in flow-loaded rodents. Flow loading reduced AAA diameter by 26% despite evidence of flow-mediated aortic enlargement proximal to the aneurysmal segment. Messenger RNA from AAA tissue was harvested for cDNA labeling and hybridization to a 384-clone DNA microarray. Twenty-nine genes were differentially expressed (relative intensity/relative intensity of control ratio >1.5 and <0.67) in flow-loaded compared with normal flow AAA tissue, including heme oxygenase 1 (HO-1). Increased HO-1 expression was confirmed via reverse transcriptase-polymerase chain reaction. Immunohistochemistry localized HO-1 expression to infiltrative macrophages. alpha-Tocopherol was found to be as effective as flow loading in limiting AAA enlargement. Flow loading and alpha-tocopherol therapy reduced AAA reactive oxygen species production. CONCLUSIONS: Flow loading may attenuate AAA enlargement via wall shear or strain-related reductions in oxidative stress.

Use of an Anastomotic Coupling Device for the Creation of Spliced Autogenous Grafts in Lower Extremity Revascularization.

INTRODUCTION: Despite a recent rise in popularity of endovascular techniques, open bypass surgery is still required for treating many lower extremity vascular lesions. Greater saphenous vein (GSV) of adequate length and caliber for successful infrainguinal lower extremity bypass is unavailable in 15% to 45% of patients. To overcome limitations imposed by absent vein due to prior use, short vessel length, or sclerotic segments, both alternate (ie, basilic and cephalic) and GSV conduits may be "spliced" together in series via venovenostomy. Although vascular surgeons typically perform a hand-sewn venovenostomy, device-based venous coupling has been performed by plastic surgeons for many years. We therefore sought to review our experience with venous coupling for segmental lower extremity bypass graft assembly. METHODS: A retrospective review was performed in all patients who underwent lower extremity revascularization using autogenous vein grafts spliced together with the Synovis (Birmingham, Alabama) anastomotic coupler at a single institution over a 5-year period. RESULTS: The anastomotic coupler device was used on 5 patients for 7 venovenostomies. The mean age of patients was 66 years, and the mean follow-up period was 751 days. Two patients were lost to follow-up, while 2 other patients died of causes unrelated to their lower extremity bypass. The average time to perform venovenostomy was 3 minutes. Three patients developed stenosis of their composite graft at a site other than the venovenostomy, who were successfully treated with either angioplasty or bypass revision. One-year primary and primary-assisted patency rates were 50% and 75%, respectively. CONCLUSIONS: Given the known benefits of the anastomotic coupling device when used for venous anastomoses in microsurgical reconstruction, transition of this device to the vascular surgery realm represents a logical progression. Although small, our series demonstrates that the anastomotic coupler can successfully be used for the formation of spliced autogenous grafts for lower extremity revascularization in the absence of adequate GSV.

Intraoperative ultrasonography improves identification of recurrent thyroid cancer.

BACKGROUND: Surgical resection is the only curative treatment option for locoregional recurrence of well-differentiated thyroid cancer that does not trap radioiodine. We hypothesized that intraoperative ultrasonography would aid in the localization of recurrent thyroid cancer and would enhance the ability to perform a complete resection. METHODS: Between June 2000 and October 2001, 13 patients with recurrent, scan-negative, papillary thyroid cancer were explored by using intraoperative ultrasonography. RESULTS: All patients had identification and resection of recurrent papillary thyroid cancer. Eleven patients had a complete resection, and 2 patients had incomplete resection as a result of local invasion. Ultrasound was required for identification of tumor in 7 patients and included all patients with a history of external beam radiotherapy. In 6 of these 7 patients, the tumor was paratracheal or invasive into the trachea or thyroid cartilage. In 11 patients with detectable serum thyroglobulin preoperatively, the level demonstrated a decline in 10 patients and became undetectable in 7 patients. CONCLUSIONS: Intraoperative ultrasonography is a useful method to identify nonpalpable, locoregional recurrences of thyroid cancer. Ultrasound was particularly helpful in patients who had previous external beam radiotherapy and in the identification of tumor nodules of 20 mm or less that were invasive or adherent to the airway.

Needle track seeding of papillary thyroid carcinoma from fine needle aspiration biopsy. A case report.

BACKGROUND: Dissemination of tumor cells from needle biopsy has been observed in a wide range of tumor types. Fine needle aspiration (FNA) biopsy has become accepted as the first-line test in the evaluation of thyroid nodules. Local recurrence of thyroid cancer from needle track seeding is an extremely rare complication of thyroid FNA. CASE: A 59-year-old woman developed local recurrence of papillary thyroid carcinoma three years after FNA of the primary cancer. Local metastases developed in the skin and sternocleidomastoid muscle. The location of the recurrent cancer and the linear relationship of the metastases indicated that local recurrence was due to needle track seeding at the time of FNA. CONCLUSION: Needle track seeding has been recognized as a possible, albeit rare, complication of FNA of thyroid cancer. Although proper FNA technique can reduce the potential for needle track seeding, its occurrence is an unavoidable complication of FNA evaluation of thyroid malignancies.

Clinical, demographic, and medicolegal factors associated with geographic variation in inferior vena cava filter utilization: an interstate analysis.

OBJECTIVES: Geographic variability exists in the use of IVC filters (IVCF). We hypothesized that variation in IVCF use is incompletely explained by variation in the prevalence of deep-vein thrombosis (DVT) and pulmonary embolism (PE) and may result from different practice patterns regarding prophylactic IVCF use. We characterize geographic variation in IVCF use at the state level and evaluate its association with clinical factors, patient demographics, and the medicolegal environment. METHODS: Healthcare Cost and Utilization Project State Inpatient Database records were accessed to identify 230,445 IVCFs placed from 2006 to 2008 in 33 states. Similar queries were performed for DVT and PE. Additional state data were obtained from public sources. Analyses included descriptive statistics, Spearman Correlation (SC), Wilcoxon rank-sum test, and characterization of variability. RESULTS: Overall, IVCF use correlated with the prevalence of DVT (SC = 0.89, P < .01). States on the East coast have significantly greater rates of IVCF use per 100K (mean ± SD = 41.2 ± 16.7 vs 27.8 ± 11.1, P < .05) and greater rates of IVCF per DVT (20.2 ± 4.5% vs 15.2 ± 2.9%; P < .005), despite similar rates of DVT per 100K (198.1 ± 51.2 vs 177.7 ± 46.7, P = NS) compared with all other states. Overall, states with the greatest rate of IVCF per DVT were (in descending order): Rhode Island, New Jersey, Florida, New York, and West Virginia. Rates of detected PE per 100K in these states were not significantly different from all other states (95.6 ± 16.6 vs 90.4 ± 16.1, P = NS). In these states, a greater percentage of IVCF recipients were older than 85 (15.3% vs 11.8%; P < .01); fewer were pediatric (0.3% vs 0.7%; P < .05) or aged 45 to 64 (26.1% vs 32.4%; P < .001). There were no differences in patient sex, race, insurance type, hospital size, or teaching status. States with high rates of IVCF per DVT were noted to have significantly greater rates of paid malpractice claims per 100K (4.9 ± 2.51 vs 1.1 ± 0.8; P = .001), and annual general surgeon liability insurance premiums ($78,630 ± 34,822 vs $43,989 ± 17,794; P < .05). CONCLUSION: Variation in IVCF use is incompletely explained by clinical factors. High rates of IVCF per DVT in some states may represent increased use of prophylactic IVCF in states with litigious medicolegal environments.

Long-term thrombotic recurrence after nonoperative management of Paget-Schroetter syndrome.

BACKGROUND: The purpose of this study was to determine the clinical predictors associated with long-term thrombotic recurrences necessitating surgical intervention after initial success with nonoperative management of patients with primary subclavian vein thrombosis. METHODS: Sixty-four patients treated for Paget-Schroetter syndrome from 1996 to 2005 at our institution were reviewed. The standardized protocol for treatment includes catheter-directed thrombolysis, a short period of anticoagulation, and selective surgical decompression for patients with persistent symptoms. First-rib resection was performed in 29 patients (45%) within the first 3 months, with a success rate of 93%. The remaining 35 patients (55%) were treated nonoperatively and constitute this study's population. RESULTS: Of the 35 patients with successful nonoperative management, 8 (23%) developed recurrent thrombotic events of the same extremity at a mean follow-up time of 13 months after thrombolysis (range, 6-33 months). These eight patients subsequently underwent first-rib resection with a 100% success rate without further sequelae at a mean follow-up time of 51 months (range, 2-103 months). The other 27 patients remained symptom free at a mean follow-up interval of 55 months (range, 10-110 months). Bivariate analyses determined that the use of a stent during the initial thrombolysis was associated with thrombotic recurrence (P = .05). The recurrence group was also significantly younger than the asymptomatic group (22 vs 36 years; P = .01). Sex, being a competitive athlete, a history of trauma, whether the dominant arm was affected, time of delay to lysis, initial clot burden, response to original lysis, use of adjunctive balloons or mechanical thrombectomy devices, residual stenosis on venography, length of time on warfarin, and patency of the vein on follow-up duplex examination were all characteristics not associated with long-term recurrence after nonoperative management. CONCLUSIONS: Conservative nonoperative management of primary subclavian vein thrombosis can be successfully used with acceptable long-term results. A younger age (<28 years old) and the use of a stent during initial thrombolysis are factors associated with long-term recurrent thrombosis. Younger patients should be offered early surgical decompression, and the use of stents without thoracic outlet decompression is not indicated.

Simulation improves resident performance in catheter-based intervention: results of a randomized, controlled study.

OBJECTIVES: Surgical simulation has been shown to enhance the training of general surgery residents. Since catheter-based techniques have become an important part of the vascular surgeon's armamentarium, we explored whether simulation might impact the acquisition of catheter skills by surgical residents. METHODS: Twenty general surgery residents received didactic training in the techniques of catheter intervention. Residents were then randomized with 10 receiving additional training with the Procedicus, computer-based, haptic simulator. All 20 residents then participated in 2 consecutive mentored catheter-based interventions for lower extremity occlusive disease in an OR/angiography suite. Resident performance was graded by attending surgeons blinded to the resident's training status, using 18 procedural steps as well as a global rating scale. RESULTS: There were no differences between the 2 resident groups with regard to demographics or scores on a visuospatial test administered at study outset. Overall, residents exposed to simulation scored higher than controls during the first angio/OR intervention: procedural steps (simulation/control) (50 +/- 6 vs. 33 +/- 9, P = 0.0015); global rating scale (30 +/- 7 vs. 19 +/- 5, P = 0.0052). The advantage provided by simulator training persisted with the second intervention (53 +/- 6 vs. 36 +/- 7, P = 0.0006); global rating scale (33 +/- 6 vs. 21 +/- 6, P = 0.0015). Moreover, simulation training, particularly for the second intervention, led to enhancement in almost all of the individual measures of performance. CONCLUSION: Simulation is a valid tool for instructing surgical residents and fellows in basic endovascular techniques and should be incorporated into surgical training programs. Moreover, simulators may also benefit the large number of vascular surgeons who seek retraining in catheter-based intervention.