Faculty Bibliography

Background: Patients who present acutely with a femoral vein deep venous thrombosis (DVT) diagnosed by ultrasound are often treated with anticoagulation and instructed to follow up electively. This study sought to assess whether obtaining central imaging in this cohort of patients results in an increased diagnosis of iliocaval DVT and consequently an increased consideration for interventional treatments to effect thrombus removal. Methods: This study was a retrospective review of a prospectively maintained RedCap database from November 2014 through August 2016, which is coordinated by the Venous Thromboembolic Center at our institution. Consecutive patients who were diagnosed by ultrasound with a femoral vein DVT were evaluated. The patients who underwent confirmatory central venous imaging (computed tomography venography, magnetic resonance venography; group A) were compared with the patients who did not undergo central venous imaging (group B). Demographic variables were collected. The outcomes evaluated were (1) the presence of iliocaval DVT, (2) candidacy for lytic-based therapies, (3) performance of lytic-based therapy, and (4) performance of any invasive treatment (lytic therapy, mechanical thrombectomy, inferior vena cava filter placement, or venous stenting). Additional outcomes included technical success of invasive treatment and complications associated with invasive treatment. Results:A total of 63 patients were identified who presented with a diagnosis of femoral vein DVT. Group A comprised 20 of 63 (31%) patients. Group B comprised the remainder, 43 of 63 (69%). The baseline demographics did not differ significantly, except for gender (Table). The number of patients who were diagnosed with an iliocaval DVT differed significantly (group A, nine [45%]; group B, nine [20%]; P <.0001). The number of patients who underwent lytic therapy differed significantly (group A, eight [40%] - seven at the index admission and one at 1 month; group B, 0 [0%]; P <.0001). The number of patients without relative contraindications to lytic therapy did not differ significantly (group A, 13 [65%]; group B, 34 [79%]; P =.35). The number of patients who underwent any invasive treatment differed significantly between the two cohorts (group A, 12/20 [60%]; group B, 4/43 [9%]; P =.0001). The majority of interventions were technically successful in both groups (group A, 11/12 [91.7%]; group B, 4/4 [100%]; P = 1.00). Conclusions: This study suggests that a significant percentage of patients diagnosed by ultrasound with femoral vein DVTs have a concomitant iliocaval DVT. The data suggest that in patients with a femoral vein DVT, central venous imaging may be indicated to identify potentially treatable iliocaval thrombosis. Long-term data will be required to see if this results in a decrease in post-thrombotic syndrome on a population basis. (table present)

OBJECTIVE: Peripheral arterial disease (PAD) disproportionally affects racial groups in the United States. Few studies have analyzed the rates of PAD in the American Indian (AI)/ Alaskan Native (AN) population. In this paper we compare the prevalence of PAD in the AI/AN as compared to white and non-white Americans. METHODS: The study data were provided by Life Line Screening (Independence, Ohio). The cohort consists of self-referred individuals who paid for vascular screening tests. Mild to moderate and severe PAD were defined as having an ankle brachial index (ABI) in at least one extremity of < .9 and <.5 respectively. Univariate and multivariate analysis were performed to compare the rates of PAD between AI/AN, Caucasians, and non-whites. RESULTS: The original sample for which this study was obtained included 3,444,272 people. Of this group there was a predominance of females 64.5% (2,221,555) compared to 35.5% (1,222,716) males. The Native American/ Alaskan Native population was 2.8% of the sample (96,440). In our univariate analysis AI/AN had the highest rates of mild-moderate and severe PAD when compared to whites (OR 1.78 and 2.14 respectively) and non-whites (OR 1.52 and 1.82 respectively). We then controlled for atherosclerotic risk factors in our multivariate analysis and the AI/NA cohort had persistently higher rates of both moderate and severe PAD compared to whites (OR 1.32 and 1.40) but not compared to non-whites (OR .95 and .92). CONCLUSIONS: Here we present the largest epidemiology study of PAD in AI/NA to date. AI/NA people have disproportionately high rates of both mild-to moderate and severe PAD when compared to whites and non-white Americans. After controlling for atherosclerotic risk factors the rates of PAD remain high for AI/NA when compared to whites but not when compared to non-whites. While it is possible that a combination of diet and lifestyle choices are responsible for the high rates of PAD in this population, genetic factors may be involved as well, and deserve further investigation. Optimal medical management may help to prevent the complications of PAD in this patient population.

We report the case of delayed reconstruction of an iatrogenically transected inferior vena cava (IVC). A 47-year-old male underwent a laparoscopic right nephrectomy complicated by an unrecognized IVC transection. Postoperatively, he developed severe lower extremity edema, abdominal distension, and discomfort, prompting further investigation. A computed tomography scan showed a staple line extending across the IVC with thrombus extending distally to the level of the left renal vein. Repair of the suprarenal portion of the IVC was undertaken using a cryopreserved femoral vein allograft. The patient demonstrated clinical improvement with follow-up imaging demonstrating graft patency at 15 months.

OBJECTIVE: The treatment of venous insufficiency using endovenous laser ablation or radiofrequency ablation may result in endothermal heat-induced thrombosis (EHIT), a form of deep venous thrombosis. This study sought to assess whether increasing the ablation distance peripheral to the deep venous junction would result in a reduction in the incidence of EHIT II. METHODS: This study was a retrospective review of a prospectively maintained database from April 2007 to December 2011. Consecutive patients undergoing great saphenous vein (GSV) or small saphenous vein (SSV) ablation were evaluated. Previous to February 2011, all venous ablations were performed 2 cm peripheral to the saphenofemoral or saphenopopliteal junction (group I). Subsequent to February 2011, ablations were performed greater than or equal to 2.5 cm peripheral to the respective deep system junction (group II). The primary outcome was the development of EHIT II or greater (ie, thrombus protruding into the deep venous system but comprising less than 50% of the deep vein lumen). Secondary outcomes included procedure-site complications such as thrombophlebitis and hematomas. chi2 tests were performed for all discrete variables, and unpaired Student's t-tests were performed for all continuous variables. P < .05 was considered statistically significant. RESULTS: A total of 4223 procedures were performed among group I (n = 3239) and group II (n = 984). Patient demographics were similar between the two groups; however, the CEAP classification was higher by a small margin in group II, and the result was significant (group I: 2.6% +/- 0.9% vs group II: 2.8% +/- 1.0%; P = .006). The incidence of EHIT II was 76 in group I and 13 in group II. This represented a trend toward diminished frequency in group II as compared with group I (group I: 2.3% vs group II: 1.3%; P = .066). There were no reported cases of EHIT III or IV in this patient cohort. Patients who developed an EHIT II in group I were treated using anticoagulation 54% of the time, and patients who developed an EHIT II in group II were treated using anticoagulation 100% of the time. CONCLUSIONS: This study suggests that changing the treatment distance from 2 cm to greater than or equal to 2.5 cm peripheral to the deep venous junction may result in a diminished incidence of EHIT II. Ongoing evaluation is required to validate these results and to affirm the long-term durability of this technique.

BACKGROUND: Endoleak and sac growth remain unpredictable occurrences after EVAR, necessitating regular surveillance imaging, including CT angiography. This study was designed to identify preoperative CT variables that predict AAA remodeling and sac behavior post-EVAR. METHODS: Pre- and postoperative CT scans from 136 abdominal aortic aneurysms treated with EVAR were analyzed using M2S (West Lebanon, NH) software for size measurements. Preoperative total sac volume and proportion of thrombus and calcium in the sac were assessed. Sac change was defined as a 3-mm difference in diameter and a 10-mm(3) difference in volume when compared with preoperative measurements. Univariate analysis was performed for age, gender, AAA size, relative thrombus/calcium volume, device type, presence of endoleak, and the effects on sac size. RESULTS: Gender, device type, age, AAA size, and percent calcium were not predictive of sac change post-EVAR. Increased proportion of thrombus on pre-EVAR resulted in a greater likelihood of sac shrinkage (P = 0.002). Patients with aneurysms that grew on postoperative CT scan had less sac thrombus on pre-EVAR (mean 27.5%) than patients without evidence of endoleak (mean 41.9%, P < 0.0001). Only 2 of 30 patients with >50% pre-EVAR thrombus developed endoleak. A >50% thrombus burden resulted in endoleak in significantly fewer patients (6.7%) compared with those who had <50% thrombus (43.1%). CONCLUSIONS: The proportion of thrombus on preoperative CT may predict sac behavior after EVAR and development of an endoleak. Greater than 50% thrombus appears to predict absence of endoleak after EVAR. Aneurysms with large thrombus burden are less likely to grow and may require less vigilant postoperative surveillance than comparable AAA with relatively little thrombus.

OBJECTIVE: Certain races are known to be at increased risk for stroke, and the prevalence of carotid artery stenosis (CAS) is thought to vary by race. The goal of this report was to study the prevalence of CAS in different races by analyzing a population of subjects who underwent vascular screening examinations. METHODS: The study data were provided by Life Line Screening. The cohort consists of self-referred individuals who paid for vascular screening tests. Subjects <40 and >100 years of age and those who reported a prior stroke or carotid artery intervention were excluded. Of the remaining 3,291,382 subjects, 3.7% did not self-identify a race. CAS was defined as stenosis in either internal carotid artery >/=50% by duplex ultrasound velocity criteria. RESULTS: The 3,291,382 subjects available for analysis consisted of Caucasian (2,845,936 [90%]), African American (97,502 [3.1%]), Hispanic (75,240 [2.4%]), Asian (60,982 [1.9%]), and Native American (87,757 [2.8%]) individuals. The prevalence of CAS was 3.4% in females and 4.2% in males (P