Contemporary outcomes for ruptured abdominal aortic aneurysms using endovascular balloon control for hypotension.

OBJECTIVE: Ruptured abdominal aortic aneurysm (rAAA) continues to portend significant mortality, despite ruptured endovascular aneurysm repair (rEVAR), enhanced perioperative care, and endovascular balloon control (EBC) for hypotension. We review our academic institution's experience using a protocol of EBC for all hypotensive patients, irrespective of type of repair. METHODS: A retrospective review was conducted of 66 cases of rAAA treated at a single academic institution from 2007 to 2016 using EBC for hypotensive patients. Demographics, comorbidities, intraoperative parameters, and clinical outcomes were recorded. Patients were studied with respect to hemodynamic status, rEVAR, or ruptured open aortic repair in the setting of EBC for hypotension. RESULTS: rEVAR was performed in 43 patients (65%) and ruptured open aortic repair in 23 patients (35%). rAAA was treated in 51 men (77%). Mean rAAA size was 7.6 mm, and mean age of the patients was 73 years. Perioperative survival was 82%. Overall survival at 30 days, 1 year, and 5 years was 71%, 65%, and 52%. Blood transfusion and severe hypotension were significant predictors of mortality at 30 days on multivariable analysis (odds ratio of 1.2 [P = .08] and 39 [P = .03], respectively). Severe hypotension was defined as a mean arterial blood pressure <65 mm Hg and vasopressor use and was present in 59% of the cohort. Normotension was defined as an absence of these conditions and was present in 12%, with 29% of patients exhibiting moderate hypotension. There was no difference in 30-day survival between normotensive and moderately hypotensive patients. The 30-day survival for severely hypotensive patients was 61% vs 85% for moderately hypotensive patients (P = .003), with a significant difference between groups that persisted at 1 year (85% vs 51%; P = .008) and 5 years (66% vs 51%; P = .017). CONCLUSIONS: Good midterm outcomes for moderately hypotensive and normotensive patients can be obtained using an EBC protocol for hypotension with a regionalized transport system directly to the operating room. Severely hemodynamically unstable rAAA patients still pose a significant challenge despite mitigation of hypotension by EBC, suggesting that survival may be compromised by factors other than hypotension alone. We still advocate for the use of EBC for all hypotensive patients as part of a defined rAAA protocol before definitive repair.

Intersocietal Accreditation Commission Accreditation Status of Outpatient Cerebrovascular Testing Facilities Among Medicare Beneficiaries: The VALUE Study.

OBJECTIVES: Accreditation of cerebrovascular ultrasound laboratories by the Intersocietal Accreditation Commission (IAC) and equivalent organizations is supported by the Joint Commission certification of stroke centers. Limited information exists on the accreditation status and geographic distribution of cerebrovascular testing facilities in the United States. Our study objectives were to identify the proportion of IAC-accredited outpatient cerebrovascular testing facilities used by Medicare beneficiaries, describe their geographic distribution, and identify variations in cerebrovascular testing procedure types and volumes by accreditation status. METHODS: As part of the VALUE (Vascular Accreditation, Location, and Utilization Evaluation) Study, we examined the proportion of IAC-accredited facilities that conducted cerebrovascular testing in a 5% Centers for Medicare and Medicaid Services random Outpatient Limited Data Set in 2011 and investigated their geographic distribution using geocoding. RESULTS: Among 7327 outpatient facilities billing Medicare for cerebrovascular testing, only 22% (1640) were IAC accredited. The proportion of IAC-accredited cerebrovascular testing facilities varied by region (χ(2)[3] = 177.1; P < .0001), with 29%, 15%, 13%, and 10% located in the Northeast, South, Midwest, and West, respectively. However, of the total number of cerebrovascular outpatient procedures conducted in 2011 (38,555), 40% (15,410) were conducted in IAC-accredited facilities. Most cerebrovascular testing procedures were carotid duplex, with 40% of them conducted in IAC-accredited facilities. CONCLUSIONS: The proportion of facilities conducting outpatient cerebrovascular testing accredited by the IAC is low and varies by region. The growing number of certified stroke centers should be accompanied by more accredited outpatient vascular testing facilities, which could potentially improve the quality of stroke care.

Accreditation status and geographic location of outpatient vascular testing facilities among Medicare beneficiaries: the VALUE (Vascular Accreditation, Location & Utilization Evaluation) study.

OBJECTIVE: There is limited information on the accreditation status and geographic distribution of vascular testing facilities in the US. The Centers for Medicare & Medicaid Services (CMS) provide reimbursement to facilities regardless of accreditation status. The aims were to: (1) identify the proportion of Intersocietal Accreditation Commission (IAC) accredited vascular testing facilities in a 5% random national sample of Medicare beneficiaries receiving outpatient vascular testing services; (2) describe the geographic distribution of these facilities. METHODS: The VALUE (Vascular Accreditation, Location & Utilization Evaluation) Study examines the proportion of IAC accredited facilities providing vascular testing procedures nationally, and the geographic distribution and utilization of these facilities. The data set containing all facilities that billed Medicare for outpatient vascular testing services in 2011 (5% CMS Outpatient Limited Data Set (LDS) file) was examined, and locations of outpatient vascular testing facilities were obtained from the 2011 CMS/Medicare Provider of Services (POS) file. RESULTS: Of 13,462 total vascular testing facilities billing Medicare for vascular testing procedures in a 5% random Outpatient LDS for the US in 2011, 13% (n=1730) of facilities were IAC accredited. The percentage of IAC accredited vascular testing facilities in the LDS file varied significantly by US region, p<0.0001: 26%, 12%, 11%, and 7% for the Northeast, South, Midwest, and Western regions, respectively. CONCLUSIONS: Findings suggest that the proportion of outpatient vascular testing facilities that are IAC accredited is low and varies by region. Increasing the number of accredited vascular testing facilities to improve test quality is a hypothesis that should be tested in future research.

Outcomes of reinterventions after subintimal angioplasty.

OBJECTIVE: With increased use of subintimal angioplasty (SIA), the role of reintervention after recurrence is currently unknown. To more clearly define the technical feasibility, patency, and clinical outcomes of reinterventions after SIA, we reviewed our cumulative experience. METHODS: A retrospective review of patient information (including demographics, indications, procedures, noninvasive arterial studies, and postprocedural events) was performed on those patients undergoing reintervention after a primary subintimal angioplasty in the infrainguinal vessels. Continuous and noncontinuous data were compared using the Student t-test and the z test, respectively. Patency was calculated by Kaplan-Meier analysis. Survival curves were compared using log-rank and Wilcoxon testing for univariate analysis and Cox hazard-regression analysis for multivariate analysis. RESULTS: From December 2002, through July 2006, 495 SIAs were performed for infrainguinal disease in 482 patients. Of this cohort, 121 patients (25%) required 188 consecutive reinterventions. Each patient underwent an average of 1.5 +/- 0.8 (range, 1-7) reinterventions during this study. We analyzed only the outcomes of 124 consecutive, first reinterventions. Mean interval time between primary SIA and the first reintervention was 7.8 +/- 6.8 months (range, 1 day-31 months). Indications for reintervention were clinical only (recurrence of symptoms or worsening exam), diagnostics only (recurrence based on peripheral vascular lab studies), or both in 18%, 25%, and 52% of patients, respectively. Technical success was achieved in 94% (n = 117) of the procedures. Repeat SIA technique was utilized in 68% (n = 84) of reinterventions and other endovascular therapies (32%; n = 40), of which the majority were transluminal angioplasty, for the remaining reinterventions. Mean follow-up was 8.6 months (range, 0-34 months). The patency rate at 1 year for the first reintervention was 33%. One-year patency rates for reinterventions performed within 3 months of the primary SIA were worse than those performed after 3 months (22% vs 34%; P = .04). In addition, patients treated for claudication had better 1-year patency than those treated for critical limb ischemia (37% vs 27%; P = .03). Other demographic or procedural variables did not significantly affect patency. In patients with critical limb ischemia (CLI), limb salvage rate at 1 year was 71%. CONCLUSION: Endovascular reintervention after SIA is a safe and technically feasible procedure for recurrences and offers good limb salvage rate. Early reinterventions performed within 3 months of the original SIA portend a worse outcome. In addition, reinterventions are less durable in patients with CLI compared with claudication. Finally, by identifying a recurrent stenosis instead of an occlusion, close surveillance may contribute to improved overall outcome.

Current literature for evidence-based infrainguinal endovascular treatment.

With the proliferation of devices and techniques for lower extremity endovascular revascularization, treatment decisions become increasingly difficult as only limited experience with these new technologies is available for review. This monograph attempts to define the current state of the literature available to guide endovascular treatment of superficial artery disease, and to provide a baseline for future studies.

Selective stenting in subintimal angioplasty: analysis of primary stent outcomes.

OBJECTIVE: Subintimal angioplasty (SIA) is being increasingly utilized to treat chronic arterial occlusions. The role of stents in SIA is currently unknown. We performed a retrospective review of selective stent use in SIA to assess outcomes and factors affecting these results. METHODS: A retrospective review of patient information--including demographics, indications, procedures, noninvasive studies, and post-procedural events--was performed on our database for patients undergoing SIA in the superficial femoral and popliteal arteries. Outcomes were calculated only on technically successful SIAs using Kaplan-Meier survival analysis. Continuous and non-continuous data were compared using the Student t test and the z test, respectively. Survival curves were compared using log-rank testing for univariate analysis and Cox hazard-regression analysis for multivariate analysis. RESULTS: Three-hundred-sixty-eight patients (382 limbs) underwent femoral and/or popliteal SIA for critical limb ischemia or disabling claudication from December 1, 2002 through July 31, 2006. Eighty-four limbs (22%) had a stent placed, while 298 (78%) did not receive a stent. Mean follow-up was 11.7 months (range, 0-45 months). One-year primary and secondary patency for stent vs no-stent group was 50% vs 45% (P = .73) and 70% vs 78% (P = .47), respectively. One-year limb salvage rate for the stent vs no-stent group was 85% vs 90% (P = .61). At 2 years, patients receiving a stent are more likely to undergo open bypass than those without a stent (P = .06). Eighty-three patients underwent 84 SIA with stent placement. The mean number of stents for each case was 1.4 +/- 0.7. Univariate analysis revealed that previous ipsilateral bypass surgery significantly decreased 1-year patency: 35% vs 56% (P = .05). SIA performed for disabling claudication had a trend toward improved 1-year patency 58% vs 39% for critical limb ischemia (P = .09). A stent diameter > or =7 mm displayed a trend toward better patency 53% vs 37% for diameter < or =6 mm (P = .08). None of these factors proved significant with multivariate analysis. CONCLUSION: Selective stents placed for suboptimal results after subintimal angioplasty produce similar patency rates to primary SIA without stents. Patients receiving stents with prior lower extremity bypass surgery will have worse outcomes than those without. Use of a stent diameter < or =6 mm and indication of critical limb ischemia will likely produce worse results. It appears that other stent variables (location, number, length, and overlap) do not alter patency. Finally, selective stent use after SIA provides excellent limb salvage.

Subintimal angioplasty: Our experience in the treatment of 506 infrainguinal arterial occlusions.

OBJECTIVE: The treatment of patients with chronic arterial occlusions involving the superficial femoral artery has changed significantly with the incorporation of subintimal angioplasty (SIA) into vascular surgery practice. To more clearly define technical feasibility, patency, and clinical outcomes of SIA, we reviewed our cumulative experience. METHODS: A retrospective review of all patients who underwent SIA of arterial occlusions originating in the superficial femoral artery was performed. Patient history, demographics, procedural details, and follow-up information were collected and analyzed. Patency, limb salvage, sustained improvement in claudication, freedom from surgical bypass, and survival were determined by Kaplan-Meier analysis. RESULTS: From December, 2002, through July, 2006, 506 infrainguinal SIA procedures were performed in 472 patients with chronic arterial occlusion involving the superficial femoral artery. The mean age of patients treated was 69.4 +/- 11.9 years and the indication for intervention was critical limb ischemia in 63% of limbs (n = 317) and disabling claudication in 37% (n = 189). Forty-seven percent of limbs (n = 237) had isolated SFA occlusions, 40% (n = 205) had femoropopliteal occlusions, and 13% of limbs had occlusions beginning in the SFA and extending into the tibial arteries (n = 64). Technical success was achieved in 87% of procedures. Following successful SIA, the mean ankle-brachial index increased by 54%, from 0.50 +/- 0.16 to 0.77 +/- 0.23 (P < .0001). Median follow-up was 12.4 months (0-48 months) and 30-day mortality was 0.8%. Primary patency at 12 and 36 months was 45% (SE 3.0%) and 25% (SE 3.6%) respectively. Secondary patency was 76% (SE 2.6%) and 50% (SE 4.8%) at 12 and 36 months. Factors associated with reduced primary patency included femorotibial occlusions (HR 1.57, CI 1.05-2.36) and the presence of critical limb ischemia (HR 1.39, CI 1.02-1.89). Limb salvage in patients with critical limb ischemia was 75% (SE 5.9%) at 36 months. Freedom from surgical bypass in patients with either critical limb ischemia or disabling claudication was 77% (SE 4.1%) at 36 months. CONCLUSION: SIA is an effective percutaneous technique for the revascularization of patients with lower extremity chronic arterial occlusions involving the superficial femoral artery. The procedure is successfully performed in all segments of the lower extremity with minimal morbidity or mortality. Rates of limb salvage and improvement in claudication are similar to those achieved by open surgical bypass, while modest reductions in limb salvage and primary patency are experienced in limbs with femorotibial occlusions.

Aneurysm regression after endovascular aneurysm repair: what should we expect?

This study reviewed a large national core laboratory database for the Ancure (Guidant, Menlo Park, California) phase I and II trial of overall aneurysm sac regression after endovascular aneurysm repair. Data were reviewed for aneurysm size and endoleak in follow-up. Endoleak was recorded as well as maximum major and minor axis aortic diameters. Included were patients with baseline assessment within 3 months of implantation and at least 24 months of follow-up, and 444 were available for review. The mean baseline aortic diameter was 56.6 mm; mean follow-up was 48.7 months. Of these patients, 129 (29.5%) had aneurysm regression to less than 40 mm, 42 (9.5%) regressed to less than 35 mm, and 12 (2.7%) had complete aneurysm sac obliteration. Multivariate analysis demonstrated that baseline aneurysm size was the only predictor of aneurysm size regression. Significant sac regression is common after Ancure aneurysm repair and appears to be related primarily to initial aneurysm size.

The natural history of autologous fistulas as first-time dialysis access in the KDOQI era.

BACKGROUND: Patients on hemodialysis depend on durable, easily maintained vascular access. The autologous arteriovenous fistula (AVF) has been the gold standard since the introduction of the Brecia-Cimino fistula in 1966 and is echoed in the current Kidney Disease Outcomes and Quality Initiative (KDOQI) guidelines. The purpose of this study is to determine the natural history of AVF in patients requiring first-time permanent access in a large academic vascular surgery practice. METHODS: We performed a retrospective review of patients undergoing new access creation from January 1, 2005 to June 30, 2005. The study group consisted of patients with no prior permanent access that underwent AVF creation. Categorical data was compared using chi2 analysis, nominal data was compared using Student t-test, and patency was determined by Kaplan-Meier curves. RESULTS: During the 6-month period, there were 80 first time AVF creations. The majority of patients were male (69%), African American (55%), and a history of diabetes (55%) and hypertension (96%). Seventy-five percent of patients were already undergoing hemodialysis via catheter access. Seventy-six percent of patients underwent preoperative vein mapping with a mean vein diameter of 3.1 mm. Twenty-six radiocephalic AVF (RCAVF) and 54 brachiocephalic AVF (BCAVF) were created with a mean follow-up of 278 days. At the end of follow-up, 38 (48%) AVF were being used for hemodialysis and only nine (11%) matured without the need for additional intervention. Mean time for AVF maturation was 146 days. Thirty AVF (37%) were abandoned, 16 (20%) of which were primary failures. Mean time to abandonment was 162 days. Twelve (15%) AVF remained patent but were never cannulated. The intervention rate was 1.33 interventions/patient/year and 75% of interventions were percutaneous. Kaplan-Meier analysis determined primary, primary-assisted, and secondary patency was 36% +/- 8.3, 55% +/- 6.5, and 55% +/- 6.5 at 1 year, respectively. Cumulative functional patency was 63% at 1 year. CONCLUSIONS: In patients receiving a first time permanent access, we found that the majority were AVF and they resulted in low primary patency rates at 1 year and long maturation times. KDOQI encourages AVF creation in order to increase AVF use for dialysis, but the strategy of simply increasing the number being created may not lead to the desired result and potentially lead to an increase in catheter dependence.

Treatment of symptomatic lower extremity acute deep venous thrombosis: role of mechanical thrombectomy.

Systemic anticoagulation with heparin or its unfractionated derivatives followed by warfarin therapy has been the mainstay of treatment in patients with lower extremity deep venous thrombosis (DVT). Although heparin is an effective treatment modality in preventing thrombus propagation, it provides minimal therapeutic effect in dissolving preexisting venous thrombus. The clinical consequence of DVT, owing in part to loss of venous endothelial and valvular function, is postphlebitic syndrome or chronic venous insufficiency. Current advances in endovascular therapy have resulted in various endovascular thrombectomy systems that can effectively remove a large venous thrombus burden, which may represent a potential advantage of preserving venous valvular function and thereby reduce the likelihood of postphlebitic syndrome. In this article, we review a variety of surgical and interventional methods in venous thrombus removal. Current treatment modalities using mechanical thrombectomy devices and pharmacomechancial thrombectomy strategy are also discussed.

Subintimal angioplasty for the treatment of claudication and critical limb ischemia: 3-year results.

OBJECTIVE: Subintimal angioplasty (SIA) is an increasingly used method of lower extremity revascularization for patients with chronic arterial occlusions. To assess the technical feasibility, safety, and 3-year outcomes of patients treated with SIA, we performed a retrospective review of our early experience. METHODS: Patient information-including demographics, indications, procedures, noninvasive arterial studies, and postprocedural events-was recorded in a database. Outcomes were determined on an intention-to-treat basis, as well as by technical success, by using Kaplan-Meier survival analysis. Continuous data were compared by using the Student t test, and survival curves were compared by log-rank testing. RESULTS: From December 2002 through December 2003, 104 patients (105 limbs) underwent SIA of 159 occlusive lesions involving the iliac (n = 10), superficial femoral (n = 85), popliteal (n = 48), or tibial (n = 16) arteries. Sixty-six (62.9%) patients were treated for critical limb ischemia, and 39 patients (37.1%) were treated for disabling claudication. Technical success was achieved in 91 procedures (86.7%) and resulted in a mean increase in ankle-brachial index of 0.36 +/- 0.16. The mean follow-up was 23.4 months (range, 0-46 months). During this period, 18 patients (17.0%) died, and 15 amputations (14.3%) were performed, 6 of which were performed for patients on whom SIA had been unsuccessful. In patients undergoing successful SIA, the primary patency was 55%, 43%, and 35% at 12, 24, and 36 months, respectively. Twenty-one patients underwent a total of 23 percutaneous procedures to maintain or restore patency of the SIA during the study period. This resulted in secondary patency rates of 71%, 63%, and 51% at 12, 24, and 36 months, respectively. Multivariate analysis revealed critical limb ischemia to be the only predictor of reduced primary patency. Fifteen patients with inoperable critical limb ischemia underwent successful SIA. Limb salvage in this group was 54% and 43% at 12 and 36 months, respectively. Limb salvage in operative candidates was 100% and 88% at the same intervals. In patients with disabling claudication, 94% experienced improvement in symptoms 3 months after the procedure, and 68% of patients reported sustained improvement at 36 months. In all operative candidates successfully treated with SIA, freedom from surgical bypass was 83% and 73% at 12 and 36 months, respectively. CONCLUSIONS: SIA for the treatment of lower extremity chronic arterial occlusions is technically feasible, results in minimal morbidity, and provides satisfactory revascularization without surgical bypass. Secondary patency is comparable to that of autologous vein bypass and is achieved with a low rate of reintervention. When used as first-line therapy, SIA provides most patients with limb salvage and freedom from surgical bypass at 3 years.

Commentary: quality improvement in symptoms, functioning, and quality of life after peripheral endovascular revascularization. Safley DM, House JA, Laster SB, Daniel WC, Spertus JA, Marso SP. Circulation. 2007;115:550-552.

available at http://circ.ahajournals.org/cgi/ content/abstract/115/5/569.

Utility of basilic vein transposition for dialysis access.

Autologous arteriovenous access is the key to long-term success with hemodialysis and is strongly supported by the National Kidney Foundation's Dialysis Outcomes Quality Initiative guidelines. Basilic vein transposition (BVT) fulfills the need for a durable conduit with high patency and maturation rates. This retrospective review examines a single group's experience with this procedure. All patients undergoing BVT for hemodialysis with available follow-up data were reviewed. Telephone interviews were used to supplement clinical data where needed. Functional assisted patency was used as the end point for this procedure, and if the access was never used for dialysis, then the patency was considered zero. Secondary interventions performed while the access remained patent and in use were not considered detrimental to the patency reported. One hundred seventy BVTs in 162 patients were performed between November 1992 and October 2001. There were 87 women (53.7%) and 112 black patients (69.1%); hypertension was present in 138 patients (85.2%) and diabetes in 89 patients (54.9%). Each year, an increasing incidence of BVT was performed in our dialysis population. The BVT was performed as the first access in that extremity in 73 of the procedures (42.9%). Functional patency (primary assisted) was achieved in 40.0% at 2 years and 15.2% at 5 years. The mean assisted patency was 14.6 months. To maintain BVT patency, 40 percutaneous secondary interventions (69.0%) and 18 surgical revisions (31.0%) occurred in 32 patients (19.0%). Ligation for swelling was necessary in 4 patients (2.5%), and steal syndrome occurred in 3 patients (1.9%). BVT is a useful autologous procedure for hemodialysis and the preferred access alternative in patients without an adequate cephalic vein. Although patencies remain poor relative to other conventional arterial vascular procedures, BVT is our most durable hemodialysis access procedure and is often the only available autologous conduit for hemodialysis.

Are we undertreating carotid stenoses diagnosed by ultrasound alone?

Clinical management of carotid disease is primarily based on results of national trials (ACAS and NASCET) that used the distal internal carotid artery diameter as a reference. However, commonly accepted ultrasound (US) criteria for carotid stenosis were derived from the correlation of velocity measurements with angiographic bulb diameter reductions (BDR). This study was undertaken to compare the degree of carotid stenosis determined by conventional velocity criteria to the degree of stenosis measured by B-mode (gray scale) diameter at both the carotid bulb and at the distal internal carotid artery, and, second, to evaluate US imaging to derive distal diameter reductions (DDR) noninvasively. During a 3-month period patients referred for carotid US were prospectively analyzed for standard velocity criteria and plaque morphology. Minimum carotid diameter was measured by longitudinal and transverse B-mode measurements and compared to carotid bulb diameter and internal carotid diameter distal to all disease. B-mode diameter reductions were compared to the degree of stenosis determined by velocity criteria and to patient symptoms and the decision for carotid endarterectomy. In total, 131 carotid arteries in 74 patients were evaluated. Based on the University of Washington velocity criteria, lesions were classified as grade I (n = 61, 46%), IIA (n = 58, 44%), IIB (n = 7, 5%), or III (n = 5, 4%). BDR measured by B-mode predicted the grade of disease based on velocity criteria (p < 0.001) with an overall accuracy of 95%. With use of the B-mode for DDR (NASCET style), 18 patients exceeded the 60% threshold for surgical intervention. Of these, only 3 patients were symptomatic and were operated on. An additional 3 operated-on patients had an asymptomatic grade III stenosis, our usual threshold for intervention. Twelve additional patients were appropriate for surgical intervention by B-mode but were not treated based on conventional velocity criteria alone. Bulb diameter reduction by B-mode imaging correlates strongly with diameter reduction determined by velocity criteria, and independently predicts the grade of carotid disease. With this in mind, the accuracy of B-mode imaging may be extended to the measurement of carotid stenosis based on DDR. By B-mode criteria, many patients appropriate for intervention were not offered treatment based on conventional velocity criteria. Modern B-mode imaging provides a noninvasive method to obtain 'arteriographic equivalent'' measurements and should be added as a routine to carotid ultrasound interrogation.

Is three-dimensional computed tomography reconstruction justified before endovascular aortic aneurysm repair?

OBJECTIVES: The endovascular management of abdominal aortic aneurysm (AAA) relies on accurate preoperative imaging for proper patient selection and operative planning. Three-dimensional (3-D) computed tomography (CT) with reformatted images perpendicular to blood flow has gained popularity as a method of AAA assessment and image-based planning before endovascular aneurysm repair (EVAR). The current study was undertaken to determine the interobserver agreement of AAA measurements obtained with axial CT and reformatted 3-D CT and to compare the consistency of the 2 methods in selecting patients for EVAR. METHODS: Eight observers assessed the axial CT and reformatted 3-D CT scans for 5 patients with AAAs to determine whether the patients were candidates for EVAR. 3-D CT with multiplanar reformatted images was performed by Medical Media Systems (MMS). Each observer measured the length and diameter of the proximal neck, maximal AAA, aortic bifurcation, common iliac diameter, and aortic angulation. The proximal neck and common iliac arteries were also assessed for thrombus, calcification, and tortuosity. Agreement of the measurements on axial CT scans was compared with those on MMS CT scans by calculating the kappa statistic. Complete agreement was defined as kappa = 1.0. The limits of agreement between observers were also calculated. RESULTS: The cumulative interobserver agreement of MMS CT scans (kappa =.81) was greater than for axial CT scans (kappa =.59). The kappa value for each of the diameter measurements was greater with the MMS CT scans. In 79% of cases the observers' measurements were less than 2 mm from the mean with MMS CT, compared with 59% for axial CT. The kappa value for deciding whether a patient was an endograft candidate on the basis of aortic neck was greater with the MMS CT (0.92 vs 0.63). The limits of agreement between observers were also better with the MMS CT. CONCLUSIONS: The interobserver agreement in planning EVAR is significantly better with MMS CT compared with traditional axial CT. The routine use of MMS CT appears justified before EVAR to improve the accuracy and consistency of patient selection.

Percutaneous treatment of symptomatic central venous stenosis [corrected].

OBJECTIVES: The increased use of central venous access primarily for hemodialysis has led to a significant increase in clinically relevant central venous occlusive disease (CVOD). The magnitude of and the optimal therapy for CVOD are not clearly established. The purpose of this study is to define the problem of CVOD and determine the success of percutaneous therapy for relieving symptoms and maintaining central venous patency. METHODS: Patients presenting with disabling upper-extremity edema suggestive of central venous stenosis or occlusion during a 3-year period were evaluated by venography of the upper extremity and central veins. Percutaneous venous angioplasty (PTA) and/or stent placement was performed as clinically indicated. The success of therapy was assessed, and the patients were observed to determine the incidence of recurrence and additional procedures. Recurrent lesions underwent similar evaluation and treatment. RESULTS: A total of 32 sides were treated in 29 patients with a mean of 1.9 interventions per side treated. Hemodialysis-related lesions were the underlying cause in 87% with the remaining 13% related to previous central venous catheterization. The lesions involved the axillary, subclavian, and innominate veins with complete venous occlusion in six (19%) cases. Percutaneous angioplasty was followed by stent placement in six (19%) cases. The procedure was a technical success and was performed without complications in all cases (100%). Mean follow-up was 16.5 months (range, 4-36 months). On average, patient symptoms were controlled for 6.5 months after the initial intervention. Recurrent edema led to additional PTA in 20 (63%) cases. Fifty percent (n = 14) of patients with an arteriovenous fistula (AVF) experienced recurrent symptoms after initial and/or repeat PTA and required AVF ligation. Complete resolution after the initial PTA was predictive of long-term success. CONCLUSIONS: Central venous occlusive disease has emerged as a significant clinical problem. Percutaneous venous angioplasty can provide temporary symptomatic relief; however, multiple procedures are often required and long-term relief is rarely achieved.

Comparison of abdominal aortic aneurysm diameter measurements obtained with ultrasound and computed tomography: Is there a difference?

OBJECTIVES: Accurate diameter measurements of abdominal aortic aneurysm (AAA) with both computed tomography (CT) and ultrasound (US) are essential for screening, planning surgical intervention, and follow-up after endovascular repair. Often there is a discrepancy between measurements obtained with CT and US, and neither limit of agreement (LOA) nor correlation between the two imaging methods has been clearly established. The purpose of this study was to assess the paired differences in AAA diameter measurements obtained with CT and US in a large national endograft trial. METHODS: CT and US measurements were obtained from an independent core laboratory established to assess imaging data in a national endograft trial (Ancure; Guidant, Menlo Park, Calif). The study included only baseline examinations in which both CT and US measurements were available. Axial CT images and transverse US images were assessed for maximal AAA diameter and recorded as CT(max) and US(max), respectively. Correlations and LOA were performed between all image diameters, and differences in their means were assessed with paired t test. RESULTS: A total of 334 concurrent measurements were available at baseline after endovascular repair. CT(max) was greater than US(max) in 95% (n = 312), and mean CT(max) (5.69 +/- 0.89 cm) was significantly larger (P <.001) than mean US(max) (4.74 +/- 0.91 cm). The correlation coefficient between CT(max) and US(max) was 0.705, but the difference between the two was less than 1.0 cm in only 51%. There was less discrepancy between CT(max) and US(max) for small AAA (0.7 cm, 15.3%) compared with medium (0.9 cm, 17.9%) and large (1.46 cm, 20.3%) AAA; however, the difference was not statistically significant. LOA between CT(max) and US(max) (-0.45-2.36 cm) exceeded the limits of clinical acceptability (-0.5-0.5 cm). Poor LOA was also found in each subgroup based on AAA size. CONCLUSIONS: Maximal AAA diameter measured with CT is significantly and consistently larger than maximal AAA diameter measured with US. The clinical significance of this difference and its cause remains a subject for further investigation.

The utility of color duplex ultrasonography in the diagnosis of temporal arteritis.

PURPOSE: Temporal arteritis (TA) is frequently diagnosed with nonspecific clinical characteristics, followed by a temporal artery biopsy to confirm the presence of vasculitis. Consequently, numerous screening surgical biopsies are performed with a high negative-biopsy rate. A prospective study was performed evaluating color duplex ultrasound scan (CDU) as the preferred method for the diagnosis of vasculitis in the evaluation of suspected TA. METHODS: Thirty-two patients with suspected TA on the basis of clinical criteria were evaluated with CDU before a temporal artery biopsy. The presence of a hypoechoic "halo," suggesting edema of the inflamed vessel, and inflammatory stenoses were noted. Histologic examinations of standard temporal artery biopsies then were performed, and the results were compared with the CDU findings. In addition, a metaanalysis was performed to identify articles related to the use of ultrasound scan in the detection of TA. RESULTS: All patients completed a bilateral CDU examination of the temporal arteries, and in 75% of patients biopsied, no evidence of vasculitis was found at histologic examination. When CDU examined for halo alone as the determinant for disease, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), compared with histologic confirmation of TA, were 85.7%, 92.0%, 75.0%, and 95.8%, respectively. With the criteria for a halo sign present, an inflammatory stenosis present, or both present on CDU, the sensitivity, specificity, positive predictive value, and NPV were 100%, 80.0%, 58.3%, and 100%, respectively. CONCLUSION: CDU is a superior noninvasive method of determining the presence of vasculitis when compared with routine surgical biopsy. Examination of the temporal artery with CDU can effectively predict which patient will need surgical biopsy. The utility of CDU in the diagnosis of TA is maintained by a high sensitivity in detecting patients with the disease and also by a high NPV that can eliminate patients who would not benefit from biopsy.