Faculty Bibliography

The purpose of this article is to describe arterial and venous thromboembolism in the abdomen, pelvis, and lower extremities. Eight-two COVID patients with abdominal ultrasound or CT were retrospectively compared with non-COVID patients for thromboembolism and solid-organ infarction. Nine (11%) COVID-19 patients had thromboembolic findings with medium to large-sized arterial thrombi in 5/82. One non-COVID patient had known portal vein thrombus on CT. Thromboembolic findings occurred more frequently in patients with than without COVID-19 (p=0.02).

Intimomedial mucoid degeneration, a rare vascular disorder characterized by mucinous deposition in the intima and media layers, causes aneurysmal degeneration of the vessel wall in young patients. Because of the potential for involvement of multiple vessels, these patients may require full body imaging and long-term follow-up. We describe three patients with intimomedial mucoid degeneration and variable clinical presentations. One patient presented emergently with a spontaneously ruptured nonaneurysmal subclavian artery; one patient presented with a known posterior tibial artery aneurysm and new onset of focal pain and paresthesias over the aneurysm; and one patient presented with a self-discovered dorsalis pedis artery aneurysm.

STUDY DESIGN/METHODS:Clinical case series. OBJECTIVE:To show the efficacy of prophylactic inferior vena cava (IVC) filters in preventing venous thromboembolic event (VTE) in high-risk patients undergoing major spinal surgery. SUMMARY OF BACKGROUND DATA/BACKGROUND:Patients undergoing major spinal surgery are at increased risk for VTEs. Recent studies have shown IVC filters are effective in preventing clinically significant pulmonary embolism (PE), but have not documented the frequency of all emboli prevented. METHODS:Patients undergoing major spinal surgery from 2006 to 2009, having IVC filters placed for VTE prophylaxis, were reviewed. Patients with 2 or more risk factors for VTE were included and their perioperative courses were reviewed for PE and device-related complications. Cavograms obtained at the time of attempted filter retrieval identified intercepted emboli. The rates of intercepted emboli and clinical PEs were compared with those of similar populations undergoing similar procedures. RESULTS:Approximately 17% of patients had entrapped thrombus present at attempted filter retrieval. An additional 17% of filters were unable to be retrieved due to change in position within the IVC. No patients experienced symptomatic PE. One patient developed a deep vein thrombus requiring pharmacologic treatment and another patient developed superficial phlebitis. There were no complications related to IVC filter use. CONCLUSIONS:These findings show that the decreased rate of PE observed in this and other series is likely because of the use of IVC filters, rather than sampling bias inherent when studying a relatively rare problem. The safety of IVC filters in this population is also confirmed. The observed rate of clinical PE is consistent with other published series. Emboli intercepted by filters may more accurately estimate clinically significant emboli prevented. Therefore, cavograms may prove to be a valuable method of assessing the efficacy of these devices in future studies.

BACKGROUND:This study evaluated patients undergoing femoropopliteal bypasses using endoscopically harvested vein to treat Trans-Atlantic Inter-Society Consensus (TASC) stage D lesions. Primary patency and primary assisted patency were evaluated, as were perioperative morbidity and mortality and hospital length of stay (LOS). Results for this minimally invasive alternative to femoropopliteal bypass with conventional open vein harvesting were analyzed. METHODS:A retrospective analysis was performed on patients who underwent femoral-popliteal bypass with endoscopic saphenous vein harvest and angiographic TASC D anatomy. Postoperative duplex exams were evaluated, and the study end points of graft thrombosis or the development of a high-grade stenosis prompting reintervention were sought. Patient demographics, morbidity, mortality, and hospital LOS were analyzed. RESULTS:Twenty-seven patients meeting our inclusion criteria underwent surgery between June 2002 and June 2007. Indications for surgery in these patients were claudication (n=10), gangrene or ulceration (n=9), and ischemic rest pain (n=8). Fifty-two percent of the patients were male, 50% had cardiac disease, 65% had hypertension, 54% were diabetic, and 65% had a significant smoking history. Median LOS was 2.5 days in claudicants, 3.0 days in patients with rest pain, and 7.0 days in patients with gangrene or ulceration (p<0.05). Kaplan-Meier primary patency and primary assisted patency rates were 73.2% and 80.8% at 1 year, respectively; and these rates were maintained for 70 months. The only perioperative complication was a superficial wound infection, and two patients died during follow-up from causes unrelated to the surgery. CONCLUSION/CONCLUSIONS:Femoropopliteal bypass using endoscopic vein harvest is a durable reconstructive vascular procedure which can be performed with minimal postoperative morbidity, short LOS, and satisfactory long-term patency.

Mesenteric ischemia (MI) is caused by compromised blood flow to the arteries supplying the small and large intestine. Acute occlusive mesenteric ischemia (AMI) presents with the abrupt onset of severe abdominal pain, which if not diagnosed and treated immediately can cause bowel necrosis and prove fatal. Chronic occlusive mesenteric ischemia (CMI) is usually a longstanding process characterized by postprandial abdominal pain, progressive food intolerance, and weight loss. If untreated, CMI can lead to progressive disability and failure to thrive. This review article highlights the clinical and radiologic diagnosis of acute mesenteric ischemia and CMI and compares their treatment with surgical revascularization and the less invasive alternative of mesenteric artery angioplasty and stenting.

Popliteal artery aneurysms account for 85% of all peripheral aneurysms and are frequently associated with abdominal aortic aneurysms. Up to 75% of all popliteal artery aneurysms are discovered in symptomatic patients who present with arterial insufficiency, leg swelling, or pain. Popliteal artery aneurysms can be diagnosed with duplex ultrasonography. Aneurysm repair should be considered for all symptomatic patients with rest pain or limb-threatening symptoms. Asymptomatic aneurysms larger than 2 cm should also be treated to prevent the development of limb-threatening ischemia and assure better surgical bypass graft patency and longer freedom from amputation. Conventional aneurysm repair consists of either opening the aneurysm sac and interposing a bypass graft or aneurysm ligation combined with bypass grafting. If the aneurysm sac is left intact, side branch perfusion may persist and the aneurysm may continue to enlarge and can rupture. Endovascular popliteal aneurysm repair has not demonstrated clinical equipoise to standard surgery but may be advantageous in select high-risk patients.

OBJECTIVE: The clinical significance of type II endoleaks is not well understood. Some evidence, however, indicates that some type II endoleaks might result in aneurysm enlargement and rupture. To identify factors that might contribute to aneurysm expansion, we analyzed the influence of several variables on aneurysm growth in patients with persistent type II endoleaks after endovascular aortic aneurysm repair (EVAR). METHODS: In a series of 348 EVARs performed during a 10-year period, 32 patients (9.2%) developed type II endoleaks that persisted for more than 6 months. Variables analyzed included those defined by the reporting standards for EVAR (SVS/AAVS) as well as other endoleak characteristics. Univariate, receiver operating characteristic curve, and Cox regression analyses were used to determine the association between variables and aneurysm enlargement. RESULTS: The median follow-up period was 26.5 months (range, 6-88 months). Thirteen patients (41%) had aneurysm enlargement by 5 mm or more (median increase in diameter, 10 mm), whereas 19 (59%) had stable or shrinking aneurysm diameter. Univariate and Cox regression analyses identified the maximum diameter of the endoleak cavity, ie, the size of the nidus as defined on contrast computed tomography scan, as a significant predictor for aneurysm enlargement (relative risk, 1.12; 95% confidence interval, 1.04-1.19; P =.001). The median size of the nidus was 23 mm (range, 13-40 mm) in patients with aneurysm enlargement and 8 mm (range, 5-25 mm) in those without expansion (Mann-Whitney U test, P <.001). Moreover, receiver operating characteristic curve and Cox regression analyses showed that a maximum nidus diameter greater than 15 mm was particularly associated with an increased risk of aneurysm enlargement (relative risk, 11.1; 95% confidence interval, 1.4-85.8; P =.02). Other risk factors including gender, smoking history, hypertension, need of anticoagulation, aneurysm diameter, type of endograft used, and number or type of collateral vessels were not significant predictors of aneurysm enlargement. CONCLUSIONS: In patients with persistent type II endoleaks after EVAR, the maximum diameter of the endoleak cavity or nidus is an important predictor of aneurysm growth and might indicate the need for more aggressive surveillance as well as earlier treatment

PURPOSE: To evaluate the fate of collateral vessels adjacent to and within the target lesion following subintimal angioplasty (SIA). METHODS: Pre and postprocedural angiograms were reviewed for 29 patients undergoing SIA of the lower extremity arteries over a 3-year period. The number of patent collateral vessels </=5 cm proximal to the occlusion (proximal segment) and </=5 cm distal to the occlusion (distal segment) were recorded pre and postprocedurally and compared. In addition, the number of collateral vessels that were re-opened within the recanalized segment following SIA was counted. RESULTS: The mean number of patent collaterals in the proximal segment was 1.9 (range 0-4) preprocedurally and 1.4 (range 0-4) postprocedurally (p<0.002). The mean number of patent collaterals in the distal segment was 1.9 (range 0-4) pre-procedurally and 1.0 (range 0-4) postprocedurally (p<0.0001). Previously absent collaterals within the recanalized segment were observed in 4 (14%) of 29 patients post-SIA. The mean number of collateral vessels within all 3 segments (proximal, treated, and distal) was 3.9 collaterals preprocedurally and 2.9 collaterals postprocedurally. CONCLUSIONS: Some collateral vessels are sacrificed during SIA, but the majority are preserved. In addition, SIA has the potential to open new collaterals within the occluded segment. These collaterals may play an important role should restenosis develop within the target segment