A new management for limb graft occlusion after endovascular aneurysm repair adding a vollmar ring stripper: the unclogging technique.

BACKGROUND: Lower extremity ischemia for limb thrombosis is a well-known adverse event after endovascular abdominal aortic aneurysm repair (EVAR), ranging from 2.6-7.4%. We report our experience in the management of graft limb occlusion that occurred in patients who underwent EVAR in our institution. In cases in which balloon catheter thrombectomy is not useful or is risky, it is important to take into consideration the use of a Vollmar ring stripper (Aesculap, San Jose, CA) to avoid dislodging or disrupting the sealing zones. This technique has taken from thromboendarterectomy the principle of detaching plaque from adventitia and transformed it in a less traumatic way for dissecting thromboses from endografts. METHODS: Between September 1999 and December 2011, 608 patients underwent EVAR in our institution. In cases of severe claudication or critical ischemia, we tried to remove the thrombus using mild Fogarty balloon traction; in cases of progressive and old stratification, we added the Vollmar ring stripper. After recanalization, if there was a stenosis, an angioplasty was performed and in most patients an adequately size Cheatham platinum stent was positioned. If the endovascular approach failed, bypass procedures were considered. RESULTS: In 608 patients over a mean follow-up time of 72 months, there were 23 cases of limb thrombosis. Fifteen of the 23 limb occlusions were identified within 6 months after aneurysm repair. The mean time to occlusion was 8.2 ± 4.3 months (range: 20 days-25 months). Presenting symptoms were mild to moderate claudication (Rutherford classification I) in 3 patients (13%), medium severe claudication (Rutherford classification IIA) in 18 patients (78.3%), and paresthesia and rest pain (Rutherford classification IIB) in 2 patients (8.7%; 1 of those patients had a loss of motor function). Four (17.4%) were stable during follow-up, and in 1 of these cases we tried thrombolysis without thrombosis resolution. In 13 (56.5%) cases, we performed balloon catheter thrombectomy with a LeMaitre over the wire embolectomy catheter (LeMaitre Vascular, Burlington, MA). In 8 of 13 (61.5%) patients with certain thrombosis characteristics, we decided to add to the balloon catheter a Vollmar ring stripper for mechanical catheter thrombectomy. In all 13 thrombectomy cases, blood flow was restored through the limb with the endograft itself. There were no episodes of graft dislocation, disruption of the sealing zones, or recurrences. In 5 (21.7%) cases, a femorofemoral crossover was performed, and in 1 (4.3%) case, an axillofemoral bypass was performed. During the follow-up period, 2 of the 5 femorofemoral crossovers closed after 6 and 8 months, respectively. CONCLUSIONS: This unclogging technique, alone or associated with Vollmar ring stripper, proves to be simple, safe, and effective in the treatment of graft limb occlusion. Additional research will help confirm the role of Vollmar ring stripper.

Funnel technique for EVAR: "a way out" for abdominal aortic aneurysms with ectatic proximal necks.

BACKGROUND: To describe an endovascular technique for proximal stent-graft fixation in patients with an abdominal aortic aneurysm and an ectatic aortic neck. METHODS: We describe a method in which using currently available devices in a hybrid assembly offers another option for circumventing the limitations of problematic proximal fixation. CONCLUSIONS: Through four examples, we illustrate the feasibility of placing a straight endograft as proximal extension of a bifurcated or aorto-uni-iliac graft in patients with a dilated proximal aortic neck. It appears secure and effective, with no type I endoleak or migration over a midterm follow-up.

Aneurysm sac "thrombization" and stabilization in EVAR: a technique to reduce the risk of type II endoleak.

PURPOSE: To evaluate the reduction in type II endoleak risk after introducing a new prevention method, "thrombization" or clotting of the aneurysm sac, during endovascular aneurysm repair (EVAR) versus the standard EVAR technique. METHODS: From September 1999 to December 2008, 469 consecutive patients underwent EVAR for AAA at our institution. In 2003, the injection of fibrin glue with or without microcoils into the aneurysm sac was added to the EVAR treatment plan ("thrombization" technique). Patients who did not meet the inclusion criterion (at least 1-year follow-up imaging) were censored at the end of 2007, leaving 404 patients eligible for the study: 224 patients (210 men; mean age 71.9+/-8.5 years, range 25-88) undergoing EVAR alone from September 1999 to May 2003 (group 1) compared to 180 patients (161 men; mean age 72.6+/-8 years, range 46-89) who underwent EVAR + thrombization from June 2003 to December 2006 (group 2). RESULTS: The 2 treatment groups were similar with regard to aneurysm morphology. No allergic or anaphylactic reactions were encountered related to the fibrin glue. Over median follow-up times of 72 months in group 1 and 26 months in group 2, there were 34 (15.2%) endoleaks in group 1 versus 4 (2.2%) in group 2 (p<0.0001). The incidence of type II endoleak was 0.25/100 person-months for group 1 versus 0.07/100 person-months for group 2. The preventive sac thrombization technique was significantly associated with a reduced risk of type II endoleak (HR 0.13, 95% CI 0.05 to 0.36; p<0.0001) regardless of the type of stent-graft fixation (infrarenal versus suprarenal). CONCLUSION: The preventive method of intrasac "thrombization" using fibrin glue injection with or without the insertion of coils proves to be a simple, low cost, safe, and effective technique to significantly reduce the risk of type II endoleaks irrespective of the endograft used.

The role of antiphospholipid antibodies toward the protein C/protein S system in venous thromboembolic disease.

The association between venous thromboembolism (VTE) and antibodies anti-Protein C (PC)/Protein S (PS) is still uncertain. We performed a case-control study to determine the risk of VTE related to the presence of these auto-antibodies considered independently of the presence of lupus anticoagulant (LAC) or anti-cardiolipin antibodies (ACA). One hundred thirty-five patients with idiopathic VTE and 164 healthy subjects were enrolled. Anti-PC and anti-PS antibodies (both IgG and IgM) were assessed using commercially available ELISA kits. Among cases there was a higher prevalence of elevated anti-PC IgM antibodies than in controls (OR 2.44, 95%CI 1.00-5.94). The presence of anti-PC IgG and anti-PS IgG and IgM antibodies was also higher in cases than in controls, but the difference was not statistically significant. Only five patients had both anti-PC or anti-PS antibodies and LAC or ACA. We performed a stepwise multivariate logistic regression analysis showing that anti-PC IgM>958 percentile was a significant predictor of VTE after adjustment for LAC or ACA (OR 2.52, 95%CI 1.01-6.24)). Larger prospective studies are needed to confirm this finding.

Low-molecular-weight heparin versus compression stockings for thromboprophylaxis after knee arthroscopy: a randomized trial.

BACKGROUND: Knee arthroscopy, the most common orthopedic operation worldwide, carries a definite risk for deep venous thrombosis; however, postsurgical thromboprophylaxis is not routinely recommended. OBJECTIVE: To evaluate whether low-molecular-weight heparin (LMWH) better prevents deep venous thrombosis and does not cause more complications than graduated compression stockings in adults having knee arthroscopy. DESIGN: Assessor-blind, randomized, controlled trial. SETTING: The Department of Knee Surgery, Abano Terme Clinic, Abano Terme (knee surgery, random assignment, and bleeding event survey), and the Unit of Angiology, University Hospital of Padua, Padua (efficacy outcomes evaluation, follow-up, data management, and analysis), Italy. PATIENTS: 1761 consecutive patients undergoing knee arthroscopy between March 2002 and January 2006. INTERVENTION: Patients were randomly assigned to wear full-length graduated compression stocking for 7 days (660 patients) or to receive a once-daily subcutaneous injection of LMWH (nadroparin, 3800 anti-Xa IU) for 7 days (657 patients) or 14 days (444 patients). The data and safety monitoring board prematurely stopped the 14-day heparin group after the second interim analysis. MEASUREMENTS: Combined incidence of asymptomatic proximal deep venous thrombosis, symptomatic venous thromboembolism, and all-cause mortality (primary efficacy end point) and combined incidence of major and clinically relevant bleeding events (primary safety end point). All patients had bilateral whole-leg ultrasonography at the end of the allocated prophylactic regimen or earlier if indicated. All patients with normal findings were followed for 3 months, and none was lost to follow-up. RESULTS: The 3-month cumulative incidence of asymptomatic proximal deep venous thrombosis, symptomatic venous thromboembolism, and all-cause mortality was 3.2% (21 of 660 patients) in the stockings group, 0.9% (6 of 657 patients) in the 7-day LMWH group (absolute difference, 2.3 percentage points [95% CI, 0.7 to 4.0 percentage points]; P = 0.005), and 0.9% (4 of 444 patients) in the prematurely stopped 14-day LMWH group. The cumulative incidence of major or clinically relevant bleeding events was 0.3% (2 of 660 patients) in the stockings group, 0.9% (6 of 657 patients) in the 7-day LMWH group (absolute difference, -0.6 percentage point [CI, -1.5 to 0.2 percentage points]), and 0.5% (2 of 444 patients) in the 14-day LMWH group. LIMITATIONS: The study was not double-blind or double-dummy. Almost half of the events making up the composite outcome measure were distal deep venous thromboses. Stockings were used instead of placebo because of local prophylaxis policies. CONCLUSION: In patients undergoing knee arthroscopy, prophylactic LMWH for 1 week reduced a composite end point of asymptomatic proximal deep venous thrombosis, symptomatic venous thromboembolism, and all-cause mortality more than did graduated compression stockings.

The incidence of venous thromboembolism in thrombophilic children: a prospective cohort study.

Antithrombin and protein C and S defects, factor V Leiden mutation, and G20210A prothrombin gene mutation are well-recognized risk factors for venous thromboembolism (VTE) in adults, especially during circumstantial situations such as trauma, immobilization, surgery, or oral contraceptive treatment. The relevance of these defects in predisposing children to VTE is still undefined. In a prospective cohort study we assessed the incidence of spontaneous and risk period-related VTE in asymptomatic children (aged 1-14 years), who were family members of a proband with an objectively diagnosed venous thromboembolic event and a documented single thrombophilic abnormality. We enrolled 143 children from 63 families. Of them, 81 (56.6%) were carriers of an inherited defect, whereas the remaining 62 were free from known genetic or acquired causes of thrombophilia. The mean observation period was 5 years (range, 1-8 years) in each group. Thirty-one risk periods occurred in the carriers group and 20 in noncarriers. Neither spontaneous nor risk period-related VTE occurred in either group during 395 and 296 observation years, respectively. However, circumstances where most of the pediatric thromboses occur (insertion of central venous lines, cancer, and cardiovascular surgery) were not encountered. In conclusion, the thrombotic risk in otherwise healthy children with a single identified thrombophilic defect appears to be very low. Common triggering conditions for VTE in thrombophilic adults do not seem to increase the thrombotic risk in children carrying the same inherited defect. Accordingly, screening for thrombophilia in otherwise healthy children younger than 15 years who belong to families with inherited defects predisposing to thrombosis seems unjustified.