[Show abstract][Hide abstract] ABSTRACT: The comparative effectiveness of the two treatment options (surgical clipping and endovascular coiling) for ruptured cerebral aneurysms has not been studied in real-world practice in the USA. We investigated the association between the treatment method for ruptured cerebral aneurysms and outcomes.
We performed a retrospective cohort study of elderly patients who underwent treatment for ruptured cerebral aneurysms from 2007 to 2012 using a 100% sample of Medicare fee-for-service claims data. An instrumental variable analysis was used to control for unmeasured confounding and to create pseudo-randomization on the treatment method. In sensitivity analysis, controlling only for measured confounding, we used propensity score conditioning and inverse probability weighting with mixed effects to account for clustering at the Hospital Referral Region (HRR) level.
During the study period 3210 patients underwent treatment for ruptured cerebral aneurysms and met the inclusion criteria. Of these, 1206 (37.6%) had surgical clipping and 2004 (62.4%) had endovascular coiling. Instrumental variable analysis demonstrated no difference between coiling and clipping in 1-year postoperative mortality (OR 1.04; 95% CI 0.70 to 1.54), likelihood of discharge to rehabilitation (OR 1.07; 95% CI 0.72 to 1.58), or 30-day readmission rate (OR 1.44; 95% CI 0.70 to 1.87). However, clipping was associated with 2.7 days longer length of stay (LOS) (95% CI 0.45 to 4.99). The same associations were present in propensity score adjusted and inverse probability weighted models.
In a cohort of Medicare patients, we did not demonstrate a difference in mortality, rate of discharge to rehabilitation, and readmissions between clipping and coiling of ruptured cerebral aneurysms. Clipping was associated with a slightly longer LOS.
Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Journal of Neurointerventional Surgery 08/2015; DOI:10.1136/neurintsurg-2015-011890 · 2.77 Impact Factor
Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 07/2015; 62(3). DOI:10.1016/j.jvs.2015.05.033 · 3.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The evaluation of patients with venous ulceration primarily includes noninvasive methods to elucidate the distribution and extent of pathology. Duplex ultrasound is the first line of investigation as it provides assessment of both reflux and obstruction conditions. In patients with iliofemoral pathology axial imaging with computed tomography (CT scan) or magnetic resonance imaging (MRI) should be performed. If the treatment of iliofemoral vein obstruction is warranted then invasive assessment using venography and/or intravascular ultrasound should be used to guide the interventional procedure. Venous valve reflux can be identified and accurately characterized by duplex ultrasound, whereas the ultrasound assessment of functional abnormality associated with obstruction is less reliable. In patients with ulceration, the evaluation for and treatment of proximal venous obstruction has resulted in improved ulcer healing.
Seminars in Vascular Surgery 06/2015; 28(1). DOI:10.1053/j.semvascsurg.2015.06.002 · 1.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The treatment of saphenous vein reflux has evolved over the years with the development of thermal ablation techniques. This study was designed to analyze the complications of endovenous ablation (EVA) using data from an open, voluntary national database.
We analyzed 349 adverse events of endovenous laser (EVLT) and radiofrequency ablation (RFA) reported in the Manufacturer and User Facility Device Experience (MAUDE) database from January 2000 to June 2012. Outcomes of interest were pulmonary embolism (PE), deep vein thrombosis (DVT), death, and device failures (i.e. broken laser tip, broken sheath).
Two hundred and three (58%) reports were patient-related injuries and the other 146 (42%) device-related failures. More complications were related to RFA compared to EVLT (216 vs. 133 procedures). Thirty (8%) non-fatal PEs and 123 (35%) DVTs were described. There were 7 (2%) peri-procedural deaths, all from PE. Of the 135 device failure reports, 41(30%) required surgical intervention. Despite an increasing number of procedures, reported events peaked around 2008 and stabilized since then. Over the past 5 years, the incidence of adverse events reported for EVLT and RFA were 1 and 2 per 10,000 procedures. The complication ratio over the years was <1:2,500 for DVT, <1:10,000 for PE, <1:50,000 for death.
EVA has gained high acceptance worldwide but the risks tend to be overlooked. Despite a very low complication rate, mortality has been reported. The complications found in MAUDE represent only a fraction as the majority of the practitioners are not aware of this database. Further investigation by a large national registry is warranted to better define the real magnitude of EVA complications.
International angiology: a journal of the International Union of Angiology 02/2015; · 0.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective Perforator vein aneurysms (PVAs) of the lower extremity have not been defined or reported. This study reports the clinical presentation of patients, the PVA characteristics, and the clinical outcome of their management. Methods Patients with signs and symptoms of chronic venous disease who had a PVA were included. Diagnosis of a PVA was made with duplex ultrasound. Normal perforator veins have a diameter of <3 mm. A PVA was defined as a diameter dilation of >9 mm, and it was always found below the deep fascia. The topography and morphology of the aneurysms were described in detail. All PVAs were treated with subfascial ligation with or without aneurysm excision. All patients were followed up for a minimum of 3 months with clinical examination and duplex ultrasound, and complications were noted. Results There were 21 aneurysms identified in 19 patients. Fourteen (73.7%) patients were female. The mean age at diagnosis was 49 years with a standard deviation of 9. Aneurysm size ranged from 9.8 to 22.2 mm, with a mean diameter of 15.7 mm and a standard deviation of 3.8. Seventeen aneurysms were fusiform, one was saccular, and one was multilobar. The perforators of the great saphenous vein distribution were most frequently involved, whereas only one involved deep vein disease. Few patients had symptoms, such as pressure and pain directly over the affected perforator. There was no association between the location and size of the PVA and the severity of chronic venous disease. Fourteen patients were treated surgically; five patients preferred conservative treatment with elastic compression stockings. Fourteen patients (73.7%) had ligation with (n = 9) or without (n = 5) excision of the aneurysm. All underwent concomitant phlebectomies, and eight of them also had ultrasound-guided foam sclerotherapy. Endovenous thermal ablation of saphenous veins was performed in seven patients, whereas two had ligation and stripping. There were four minor postoperative complications in four patients, all of which resolved within 6 weeks. The median follow-up was 21 months, ranging from 3 to 52 months. There were no recurrences of a PVA. Five patients preferred conservative treatment. The diameter changed from 0 to 13 mm during the follow-up, and the patients' symptoms remained the same or had mild worsening. Conclusions PVAs are rare without causing significant symptoms locally. Diagnosis is made with duplex ultrasound because the affected vein is located below the deep fascia. As only one case in our series of 19 involved the deep veins, we believe that PVAs originate from superficial veins. The condition is relatively benign, and the treatment outcomes are very good with limited complications experienced. However, selective treatment of PVAs may not be needed for most of them as treatment of the superficial veins connecting with the PVA may be sufficient.
[Show abstract][Hide abstract] ABSTRACT: Background:
This study was presented at Scientific Session 3 at the 2015 American Venous Forum, Palm Springs, California, February 2015Proper assessment of venous thromboembolism (VTE) risk level in hospitalized patients is vital to providing adequate prophylaxis. Clinical decision support (CDS) tools with electronic medical record (EMR) have been used by institutions to improve assessment and prophylaxis. As such, this study was conducted after implementing such a system to compare admitting service (AS) assessment of VTE risk level to the VTE consult service (CS) assessment. In addition, compliance of ordered prophylaxis based on AS assessment was evaluated.
At a tertiary care center, we performed a review of randomly selected patients assessed within 18 h of admission for VTE risk over a five-month period. A total of 104 patients were evaluated, four of which were excluded because of VTE presence on admission. Patients were assessed for VTE risk independently, first by the AS, followed by the VTE CS. Prophylaxis orders were then reviewed based on AS assessment compliance to CDS recommendations for prophylaxis based on ACCP guidelines.
All 100 patients underwent VTE risk assessment within 18 h from admission. The mean age was 63 years. Comparing AS to CS assessment, 13 patients had incorrect assessments (p < .001). Of these, six patients were under-assessed (p = .029), and seven patients were over-assessed (p = .014). Based on AS assessment there were eight patients who had incorrect prophylaxis ordered. Unnecessary exposure to complications due to inappropriate prophylaxis occurred in five patients.
Despite the use of EMR CDS tools, there continues to be a significant number of patients that are being under-assessed and under-prophylaxed for VTE resulting in exposing patients to potential harm. Quality programs need to be instituted to further improve VTE assessment and prophylaxis.
[Show abstract][Hide abstract] ABSTRACT: A mathematical approach of blood flow within an abdominal aortic aneurysm (AAA) with intraluminal thrombus (ILT) is presented. The macroscale formation of ILT is modeled as a growing porous medium with variable porosity and permeability according to values proposed in the literature. The model outlines the effect of a porous ILT on blood flow in AAAs. The numerical solution is obtained by employing a structured computational mesh of an idealized fusiform AAA geometry and applying the Galerkin weighted residual method in generalized curvilinear coordinates. Results on velocity and pressure fields of independent cases with and without ILT are presented and discussed. The vortices that develop within the aneurysmal cavity are studied and visualized as ILT becomes more condensed. From a mechanistic point of view, the reduction of bulge pressure, as ILT is thickening, supports the observation that ILT could protect the AAA from a possible rupture. The model also predicts a relocation of the maximum pressure region toward the zone proximal to the neck of the aneurysm. However, other mechanisms, such as the gradual wall weakening that usually accompany AAA and ILT formation, which are not included in this study, may offset this effect.
Computer Methods in Biomechanics and Biomedical Engineering 01/2015; DOI:10.1080/10255842.2014.989389 · 1.77 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cost containment is the cornerstone of the Affordable Care Act. Although studies have compared the cost of cerebral aneurysm clipping (CAC) and coiling, they have not focused on identification of drivers of cost after CAC, or prediction of its magnitude. The objective of the present study was to develop and validate a predictive model of hospitalization cost after CAC.
We performed a retrospective study involving CAC patients who were registered in the Nationwide Inpatient Sample (NIS) database from 2005 to 2010. The two cohorts of ruptured and unruptured aneurysms underwent 1:1 randomization to create derivation and validation subsamples. Regression techniques were used for the creation of a parsimonious predictive model.
Of the 7798 patients undergoing CAC, 4505 (58%) presented with unruptured and 3293 (42%) with ruptured aneurysms. Median hospitalization cost was US$24 398 (IQR $17 079 to $38 249) and $73 694 (IQR $46 270 to $115 128) for the two cohorts, respectively. Common drivers of cost identified in the multivariate analyses included the following: length of stay, number of admission diagnoses and procedures, hospital size and region, and patient income. The models were validated in independent cohorts and demonstrated final R(2) values very similar to the initial models. The predicted and observed values in the validation cohort demonstrated good correlation.
This national study identified significant drivers of hospitalization cost after CAC. The presented model can be utilized as an adjunct in the cost containment debate and the creation of data driven policies.
Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Journal of Neurointerventional Surgery 01/2015; DOI:10.1136/neurintsurg-2014-011575 · 2.77 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Rupture of abdominal aortic aneurysm (AAA) is associated with high mortality rates. Risk of rupture is multi-factorial involving AAA geometric configuration, vessel tortuosity, and the presence of intraluminal pathology. Fluid structure interaction (FSI) simulations were conducted in patient based computed tomography scans reconstructed geometries in order to monitor aneurysmal disease progression from normal aortas to non-ruptured and contained ruptured AAA (rAAA), and the AAA risk of rupture was assessed. Three groups of 8 subjects each were studied: 8 normal and 16 pathological (8 non-ruptured and 8 rAAA). The AAA anatomical structures segmented included the blood lumen, intraluminal thrombus (ILT), vessel wall, and embedded calcifications. The vessel wall was described with anisotropic material model that was matched to experimental measurements of AAA tissue specimens. A statistical model for estimating the local wall strength distribution was employed to generate a map of a rupture potential index (RPI), representing the ratio between the local stress and local strength distribution. The FSI simulations followed a clear trend of increasing wall stresses from normal to pathological cases. The maximal stresses were observed in the areas where the ILT was not present, indicating a potential protective effect of the ILT. Statistically significant differences were observed between the peak systolic stress and the peak stress at the mean arterial pressure between the three groups. For the ruptured aneurysms, where the geometry of intact aneurysm was reconstructed, results of the FSI simulations clearly depicted maximum wall stress at the a priori known location of rupture. The RPI mapping indicated several distinct regions of high RPI coinciding with the actual location of rupture. The FSI methodology demonstrates that the aneurysmal disease can be described by numerical simulations, as indicated by a clear trend of increasing aortic wall stresses in the studied groups, (normal aortas, AAAs and rAAAs). Ultimately, the results demonstrate that FSI wall stress mapping and RPI can be used as a tool for predicting the potential rupture of an AAA by predicting the actual rupture location, complementing current clinical practice by offering a predictive diagnostic tool for deciding whether to intervene surgically or spare the patient from an unnecessary risky operation.
[Show abstract][Hide abstract] ABSTRACT: Purpose:
To investigate the variability in head computed tomographic (CT) scanning in patients with hemorrhagic stroke in U.S. hospitals, its association with mortality, and the number of different physicians consulted.
Materials and methods:
The study was approved by the Committee for the Protection of Human Subjects at Dartmouth College. A retrospective analysis of the Medicare fee-for-service claims data was performed for elderly patients admitted for hemorrhagic stroke in 2008-2009, with 1-year follow-up through 2010. Risk-adjusted primary outcome measures were mean number of head CT scans performed and high-intensity use of head CT (six or more head CT scans performed in the year after admission). We examined the association of high-intensity use of head CT with the number of different physicians consulted and mortality.
A total of 53 272 patients (mean age, 79.6 years; 31 377 women [58.9%]) with hemorrhagic stroke were identified in the study period. The mean number of head CT scans conducted in the year after admission for stroke was 3.4; 8737 patients (16.4%) underwent six or more scans. Among the hospitals with the highest case volume (more than 50 patients with hemorrhagic stroke), risk-adjusted rates ranged from 8.0% to 48.1%. The correlation coefficient between number of physicians consulted and rates of high-intensity use of head CT was 0.522 (P < .01) for all hospitals and 0.50 (P < .01) for the highest-volume hospitals. No improvement in 1-year mortality was found for patients undergoing six or more head CT scans (odds ratio, 0.84; 95% confidence interval: 0.69, 1.02).
High rates of head CT use for patients with hemorrhagic stroke are frequently observed, without an association with decreased mortality. A higher number of physicians consulted was associated with high-intensity use of head CT.
[Show abstract][Hide abstract] ABSTRACT: Objective:
To evaluate the results of radiofrequency ablation (RFA) of the great saphenous vein (GSV) using one versus two 20 s energy cycle treatment in the proximal 7 cm segment of the GSV.
All patients who underwent RFA of the GSV from 1 May 2013 to 30 September 2013 in eight of our vein centers were included. Duplex ultrasound scans (DUSs) were performed prior to treatment on all patients and 2-3 days, and 1 month after procedure. Demographic data, GSV diameters, and other relevant data were recorded. Clinical, Etiologic, Anatomic, Pathologic (CEAP) classification and Venous Clinical Severity Scores (VCSSs) were determined prior to ablation and one month later. Patients who developed endovenous heat induced thrombosis (EHIT) were followed till resolution.
A total of 205 patients had one cycle treatment (group A) and 204 had two cycle treatment (group B). The two groups were comparable in their demography, CEAP classification, and VCSS scores. The rate of failure of ablation and incidence of EHIT were also not significantly different. The incidence of complications was low, <5% in both groups and all were minor.
Two cycle treatment of the proximal GSV for vein ablation does not improve the success rate of vein closure in the short term, compared to one cycle treatment. It also does not increase the risks of DVT, EHIT, major bleeding, and other complications. However, we do not know at what diameter two cycles may be superior to one cycle.
[Show abstract][Hide abstract] ABSTRACT: Aim:
There is wide regional variability in the volume of procedures performed for similar surgical patients throughout the United States. We investigated the association of the intensity of neurosurgical care with the diffusion of the novel technology of cerebral aneurysm coiling.
We performed a retrospective cohort study involving patients who underwent any neurosurgical procedure from 2005-2010 and were registered in the National Inpatient Sample (NIS) database. A sub-cohort of patients undergoing aneurysm clipping or coiling was also created. Regression techniques were used to investigate the association of the average risk-adjusted intensity of neurosurgical care with the average rate of coiling.
There were significant disparities in the rate of coiling among several states (ANOVA, P<0.0001). It ranged from 0.24 in Maryland, where clipping was very predominant, to 0.82 in Minnesota, where coiling was the main treatment modality used. In multivariate analysis, higher coiling rate was associated with increased age, higher income, rural hospital location, and small institution size. The Midwest was association with higher rate in comparison to the Northeast, whereas the West and the South had even lower rates. Increasing rate of coiling was associated with increasing intensity of neurosurgical care. There was a positive correlation of the average risk-adjusted intensity of neurosurgical care with the average rate of coiling per state (Pearson's ρ=0.43, P<0.001).
We observed significant disparities in the rate of coiling in the United States. Increased intensity of neurosurgical care was positively associated with the integration of coiling in treatment of cerebral aneurysms.
International angiology: a journal of the International Union of Angiology 10/2014; 33(5):446-54. · 0.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Fibromuscular dysplasia (FMD) is a nonatherosclerotic, noninflammatory vascular disease that most commonly affects the renal and extracranial carotid arteries. We present 3 cases of renal infarction complicating renal artery FMD in 42-, 43-, and 46-year-old females and provide a comprehensive review of the literature on this topic. In our patients, oral anticoagulation therapy was used to treat all cases of infarction, and percutaneous angioplasty was used nonemergently in one case to treat refractory hypertension. All patients remained stable at 1-year follow-up. This is consistent with outcomes in previously published reports where conservative medical management was comparable to surgical and interventional therapies. Demographic differences may also exist in patients with renal infarction and FMD. A higher prevalence of males and a younger age at presentation have been found in these patients when compared to the general population with FMD.
Vascular and Endovascular Surgery 09/2014; 48(7-8). DOI:10.1177/1538574414551206 · 0.66 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
Information on ovarian vein thrombosis (OVT) is limited to some retrospective studies. The purpose of this prospective study was to evaluate the natural history and treatment outcomes of OVT.
Patients with documented symptomatic OVT who were treated with anticoagulation and had at least 3 months of follow-up were included. Outcomes of interest were recanalization rates, pain resolution, pelvic congestion syndrome, recurrent deep venous thrombosis (DVT), and mortality. All patients underwent clinical examination and duplex ultrasound; computed tomography venography was selectively performed.
There were 23 women with a mean age of 44 years (range, 23-68 years). Fifteen (65%) right, 5 (22%) left, and 3 (23%) bilateral OVTs were detected. The median follow-up was 27 months (range, 3 months-7 years). The most common presentation was abdominal pain in nine patients (39%), followed by flank pain in six (26%). Two patients (9%) presented with dyspnea due to pulmonary embolism. The most prevalent condition was the puerperium (n = 9; 39%). Complete recanalization occurred in 16 veins (61%), partial recanalization in four veins (15%), and occlusion in six veins (24%) while patients were receiving anticoagulation. Four patients (17%) had lower extremity DVT during follow-up after the interruption of anticoagulation. Three patients (13%) developed pelvic congestion syndrome. All four deaths (17%) were due to cancer-related complications.
Symptomatic OVT is rare. Patients fare well with anticoagulation; complete recanalization occurs in about two thirds of the patients. Recurrent DVT is found in lower extremity veins after the interruption of anticoagulation in 17% of patients; mortality was seen only in cancer patients.
[Show abstract][Hide abstract] ABSTRACT: Aim:
Chronic venous disease (CVD) is the result of venous reflux, obstruction or a combination of both. So far, attempts to correlate venous hemodynamic measurements with symptoms and signs of CVD have produced poor to moderate results, probably because of lack of methods to quantitate obstruction and combine measurements of reflux and obstruction. Our hypothesis is that the combination of quantitative measurements of (a) overall reflux (superficial and deep) and (b) overall outflow resistance i.e. including the collateral circulation would provide a hemodynamic index that should be related to the severity of the disease.
Twenty-five limbs with chronic venous disease and 1 limb from a healthy volunteer (VCSS 0-13) were studied. The clinical CEAP classification was C0 in one limb, C1 in 2 limbs, C2 in 10 limbs, C3 in 3 limbs, C4 in 1 limb, C5 in 6 limbs and C6 in 3 limbs. Air-plethysmography was used to measure reflux (VFI in mL/s) when the subject changed position from horizontal to standing. Subsequently, with the subject horizontal and the foot elevated 15 cm, simultaneous recordings of pressure and volume were made on release of a proximal thigh cuff inflated to 70 mmHg. Pressure change was recorded with a needle in the foot and volume change with air-plethysmography. Flow (Q in mL/min) was calculated at intervals of 0.1 seconds from tangents on the volume outflow curve. Outflow resistance (R) was calculated at 0.1 second intervals by dividing pressure by the corresponding flow (R=P/Q). R increased markedly at pressures lower than 25 mmHg due to decrease in vein cross-sectional area, so resistance at 25 mmHg (R25) was used in this study.
In a multivariable linear regression analysis with VCSS as the dependent variable, both VFI and R25 were independent predictors (P<0.001). Using the constant (0.595) and regression coefficients, the regression equation provided a Hemodynamic Index (HI) or estimated VCSS=0.595 + (VFI x 0.41) + (R25 x 98). Thus, HI could be calculated for every patient by substituting VFI and R25 in the equation. HI or calculated VCSS was linearly related to the observed VCSS (r=0.86).
The results indicate that the combination of quantitative measurements of reflux and outflow resistance provide a hemodynamic index which is linearly related to the VCSS. These findings need to be confirmed in larger series.
International angiology: a journal of the International Union of Angiology 05/2014; 33(3). · 0.83 Impact Factor