Use of Endoscopic Vein Harvest Yields Improved Outcomes in Popliteal Artery Aneurysm Repair.

BACKGROUND: There is growing literature showing that endoscopic vein harvest (EVH) is safe, with excellent patency rates and decreased wound complications when treating infrainguinal occlusive disease. Our institution has performed EVH since 2003 with a dedicated team of providers specializing in endoscopic vein harvest. The purpose of this study was to evaluate major outcomes of EVH as an adjunct to standard, open operative repair of popliteal artery aneurysms. METHODS: We performed a 12-year retrospective single-institution chart review from January 2005 to December 2017, identifying all patients undergoing popliteal artery aneurysm repair with EVH. Primary outcomes were procedural technical success, operative time, wound complication, major morbidity, and freedom from amputation. RESULTS: A total 37 limbs (in 31 patients) received EVH popliteal artery aneurysm repair at an average age of 65.2 ± 10 years; 65% of the patients presented without symptoms or with claudication and 35% with rest pain or tissue loss. Coexisting aneurysm was present in 68% of patients: 49% had contralateral popliteal artery aneurysms and 19% had concurrent aortic aneurysms. Of 37 limbs, 33 (89%) were treated through a medial approach with aneurysm ligation, and 4 patients (11%) were treated through a posterior approach. The average vein size was 4.4 ± 1.1 mm, with 86% harvested by the ipsilateral great saphenous vein. Average operative time was 3.89 ± 0.82 hr, with a median hospitalization of 2 days and a median of 1 day of intravenous narcotics use. Only 2 patients (5.4%) had Szilagyi class-2 surgical site infections remedied with debridement and antibiotics. Kaplan-Meier data showed a 5-year primary patency of 82.3% and primary-assisted patency of 88.2%. Additionally, 30-day primary patency was 89.2% and primary-assisted patency of 97.3%. CONCLUSIONS: EVH for popliteal aneurysmal disease provides a safe and efficacious means of popliteal artery aneurysm repair with shorter hospitalization, lower wound complication rates, and excellent long-term patency compared to standard open technique.

Outcomes of Dexmedetomidine with Local Regional Anesthesia in Carotid Endarterectomy.

BACKGROUND: Adequate sedation to complement regional techniques in carotid endarterectomy (CEA) can be challenging. Dexmedetomidine has both analgesic and amnesic properties and is reported to be a safe and acceptable alternative to conventional general endotracheal anesthesia (GETA). Outcomes observing dexmedetomidine in conjunction with regional anesthesia in CEA are not well described or known. OBJECTIVE: Compare the immediate (during hospitalization) and short-term (within 30 days of hospitalization) postoperative outcomes in patients who underwent CEA using GETA versus local regional anesthesia (LRA) alone versus dexmedetomidine with LRA at a single institution to determine whether dexmedetomidine is a safe adjunct and if there are anesthesia advantages over LRA alone. METHODS: A retrospective cohort study from January 2015 to December 2019 at Saint Joseph Mercy Ann Arbor. Patients were stratified into three groups based on anesthesia type: GETA, LRA, and dexmedetomidine (D) + LRA. Primary outcomes included stroke, myocardial infarction (MI), and death. Patient demographics were characterized and adjusted using propensity score weighting. RESULTS: Three hundred seventy nine patients met inclusion criteria; 182 patients in the GETA group, 66 in the D + LRA, and 131 in LRA. There were no significant differences across anesthesia groups in primary outcomes of stroke, MI, and death during the admission. The GETA group had significantly longer length of stay (LOS) compared to the D + LRA group (LOS = 1.51 days versus 0.85 days; P = 0.011) and the LRA group (LOS = 1.08 days; P = 0.003). However, there was no significant difference in hospital LOS between the D + LRA group and LRA only groups (P = 0.952). There was no significant difference between stroke (LRA 0.87%, GETA 0.85%, and LRA + Dex 3.52%), MI (LRA 0%, GETA 0.49%, LRA + Dex 0%), or death (LRA 5.24%, GETA 1.16%, LRA + Dex 0%), within 30 days between all three of the anesthesia groups. There was no significant difference in postoperative pain scores when comparing the GETA group (mean 1.3, standard deviation [SD] 2.5) to LRA (mean 1.2, SD 2.1) and between LRA and D + LRA (mean 0.9, SD 2.1). Procedure time (time of skin incision to closure) and total room time were comparable among all three anesthesia groups (LRA 2.2 hr, SD 2.2; GETA 2.1 hr, SD 0.5; LRA + Dex 2.1 hr, SD 0.5). CONCLUSIONS: The use of dexmedetomidine in addition to LRA is a safe and acceptable alternative to conventional GETA or LRA alone in CEA with shorter length of hospital stay when compared with GETA, improved patient tolerance based on physician observation, and similar rates of immediate and short-term complications and postoperative pain scores.

Successful paraclavicular surgical decompression for recurrent venous thoracic outlet syndrome following transaxillary first rib resection in an elite athlete.

OBJECTIVES: Recurrent effort thrombosis after prior surgical intervention for venous thoracic outlet syndrome (TOS) is an uncommon problem, and there are multiple alternative surgical approaches in the management of recurrent venous TOS. METHODS: We present a case of a 23 year-old female professional athlete who presented with arm swelling, pain, and recurrent effort thrombosis after prior transaxillary rib resection. Imaging at our institution revealed subclavian vein thrombosis, confirmed with dynamic venography, as well as a remnant first rib. RESULTS: Thrombolysis of the subclavian vein and balloon angioplasty was followed by paraclavicular thoracic outlet decompression with complete first rib resection. Success was confirmed with intraoperative dynamic venography demonstrating a patent subclavian vein and resulted in complete elimination of symptoms. CONCLUSION: Additional surgical decompression with complete medial first rib resection of remnant rib, which was potentially causing compression of the subclavian vein, may be necessary to prevent recurrent venous compression and thrombosis for venous TOS.

Ten-year experience of infrainguinal bypass with endoscopic vein harvest.

OBJECTIVES: There is conflicting data comparing minimally invasive vein harvest (MIVH) using endoscopic technique and open vein harvest (OVH) in terms of bypass patency, wound infection incidence, and patient morbidity. Our institution has performed MIVH since 2003 for peripheral bypass procedures with a consistent team of specialized endoscopic vein harvesters. This study reviewed the major outcomes of MIVH infrainguinal bypass at our institution given a predominant cohort of critical limb ischemia. METHODS: We performed a 10-year, retrospective, single-institution review from January 2005 to December 2014, identifying all patients undergoing MIVH for obstructive infrainguinal disease. Primary outcomes were primary patency, operative time, intraoperative complications, surgical site infection (SSI), and freedom from amputation. RESULTS: A total of 289 patients (70% male) underwent MIVH infrainguinal bypass at an average age of 68 ± 12 years old, an obesity prevalence of 28%, and with critical limb ischemia in 81% of the patient cohort (20% rest pain, 61% tissue loss/gangrene). Ninety-four percent of patients had no intraoperative complications, 2.5% had adverse cardiac or technical complications, and 4.2% of patients required transfusion. Average operative time was 4.2 h. Femoral-popliteal TASC classification C and D constituted 80% of our patient cohort. At the last follow-up, toe pressures had increased from 30 ± 30 to 62 ± 40 mmHg (p < 0.0001). Primary bypass patency in the first 30 days was 95%. SSI incidence requiring surgical treatment was only 6%. Our median length of stay was 4.0 days, with median intravenous narcotic use of 1 day. In addition, 77% of patients returned to their baseline mobility at first follow-up (median 19 days), and 83% of patients had freedom from amputation at last follow-up (median 820 days). CONCLUSIONS: In a center with experience in MIVH and a consistent group of experienced endoscopic vein harvesters, MIVH bypass has excellent patency, low surgical site infection, short length of stay, and prompt return to baseline mobility.

Efficacy and utilization of intravascular ultrasound in office-based lower extremity endovascular interventions for peripheral arterial disease.

OBJECTIVES: Intravascular ultrasound (IVUS) is a uniquely objective but underutilized imaging modality in the interventional treatment of peripheral arterial disease treatment. IVUS has been shown to improve device size selection and diagnose occult pathology difficult to see with routine angiography. We hypothesize that the use of IVUS in lower extremity endovascular intervention improves accuracy in stent and balloon size selection and minimizes contrast use. METHODS: This is a retrospective case series performed at a single-institution outpatient center by two vascular surgeons from July 2016 through July 2017. We identified 94 total IVUS-assisted procedures. We collected data regarding demographics, balloon and stent size, IVUS-determined vessel diameter, pre-procedure and post-procedure ABI values, and contrast used during the procedure. An independent core laboratory was further utilized to characterize all IVUS and angiographic size vessel measurements. RESULTS: For the 94 lower extremity IVUS-assisted interventions, the average patient age was 70±9 years old, with an average contrast use of 37.1 mL of Omnipaque 300. There was substantial improvement in pre- and post-procedure ABI (0.7±0.23 to 0.94±0.21). On analysis of average intraluminal IVUS vessel diameter to balloon angioplasty used, we had a correlation in size of 0.96±0.16 in our series. Additionally, in eight instances IVUS allowed for identification of a flow-limiting dissection with subsequent stenting. CONCLUSIONS: Routine use of IVUS offers a powerful diagnostic paradigm that has the potential to significantly decrease contrast use and to improve objectivity in choosing appropriate vascular tools to maximize intra-procedural efficacy. The discovery of adverse findings not initially noticed on angiography further reinforces the value of IVUS utilization.

Rapid, midline retroperitoneal exposure for four-level anterior lumbar interbody fusion-technical case atlas.

We describe a novel, rapid midline retroperitoneal operative technique in a patient, with multi-level degenerative scoliosis, who underwent an extensive L2-S1 anterior lumbar interbody fusion in addition to posterior instrumentation. Uniquely, our approach enables an essentially midline approach to the rectus muscle and uses the diminution of the transversalis fascia-to-peritoneum transition in the pelvis to provide expedited exposure-making it particularly helpful for ALIF exposure, retraction and intraoperative radiography. We minimize morbidity around the rectus sheath by dissecting only the medial rectus muscle and then gently, bluntly mobilizing the retroperitoneum from the deep pelvis cranially.

Hybrid-based iliofemoral endarterectomy for severe and complete iliofemoral occlusive disease.

OBJECTIVE: Primary endovascular approaches are now the dominant modality for the treatment of iliac occlusive disease. However, stenting of the external iliac artery is plagued with high in-stent restenosis rates. This hybrid approach with fluoroscopic, retrograde iliofemoral endarterectomy combined with stenting was previously demonstrated to be both a safe and effective alternative to bypass and primary stenting alone for TransAtlantic Inter-Society Consensus (TASC) II C and D lesions. In this study, early outcomes and hemodynamic improvements of this hybrid approach are evaluated with an expanded patient population. METHODS: This was a single-institution, retrospective review of all hybrid-based retrograde iliofemoral endarterectomies from the common femoral artery extending to the proximal external iliac artery from January 1, 2010, to November 15, 2017. Data were collected from the electronic medical record and analyzed using standard quantitative statistical techniques. All preprocedure and postprocedure imaging was independently reviewed by two vascular surgeons. Variables included patient demographics, degree of ischemia, and stent characteristics. The primary outcomes were mortality and freedom from amputation, with secondary outcomes including changes in the ankle-brachial index and toe pressure. RESULTS: The procedure was performed on 63 limbs in 51 total patients. In 33 limbs, the indication was critical limb ischemia (tissue loss/gangrene = 17, rest pain = 16) and 30 for lifestyle-limiting claudication. The cohort consisted of 84% TASC D and 16% TASC C. External iliac stenting was required in 68% (modal diameter, 10 mm) and ipsilateral common iliac stenting was completed in 75% (modal diameter, 9 mm). The ankle-brachial index significantly improved from 0.42 ± 0.25 to 0.73 ± 0.27 (P < .001) as did toe pressure from 29 ± 27 mm Hg to 59 ± 34 mm Hg (P < .001). Thirteen limbs ultimately required an infrainguinal procedure. One patient experienced an intraoperative iliac perforation that resolved with stenting. One death occurred within 90 days. Ninety-five percent of patients remained free from amputation. CONCLUSIONS: Extensive hybrid-based, retrograde iliofemoral endarterectomy with stenting is a safe and efficacious approach to severe iliac arterial occlusive disease, with excellent early outcomes. This series promulgates the hypothesis that extensive endarterectomy with selective iliac stenting yields superior results to external iliac stenting alone. Given the superb hemodynamic improvements in a larger patient population, this hybrid-based, extensive iliofemoral endarterectomy should be recommended as a minimally invasive, first-line treatment for severe iliac occlusive disease.

Hybrid MPI-MRI System for Dual-Modal In Situ Cardiovascular Assessments of Real-Time 3D Blood Flow Quantification-A Pre-Clinical In Vivo Feasibility Investigation.

Non-invasive quantification of functional parameters of the cardiovascular system, in particular the heart, remains very challenging with current imaging techniques. This aspect is mainly due to the fact, that the spatio-temporal resolution of current imaging methods, such as Magnetic Resonance Imaging (MRI) or Positron Emission Tomography (PET), does not offer the desired data repetition rates in the context of real-time data acquisition and thus, can cause artifacts and misinterpretations in accelerated data acquisition approaches. We present a fast non-invasive and quantitative dual-modal in situ cardiovascular assessment using a hybrid imaging system which combines the new imaging modality Magnetic Particle Imaging (MPI) and MRI. This pre-clinical hybrid imaging system provides either a 0.5 T homogeneous B0 field for MRI or a 2.2 T/m gradient field featuring a Field-Free-Point for MPI. A comprehensive coil system allows in both imaging modes for spatial encoding, signal excitation and reception. In this work, 3-dimensional anatomical information acquired with MRI is combined with in situ sequentially acquired time-resolved 3D (i.e. 3D + t) MPI bolus tracking of superparamagnetic iron oxide nanoparticles. MPI data were acquired during a 21 [Formula: see text] (40 µ mol(Fe)/kgBW) bolus tail vein injection under free-breathing with an ungated and non-triggered MPI scan with a repetition rate of 46 volumes per seconds. We successfully determined quantitative hemodynamics as 3D + t velocity vector estimations of a beating rat's heart by analyzing 3 seconds of 3D + t MPI image data. The used hybrid system allows for MR-based MPI Field-of-View planning and cardiac cross-sectional anatomy analysis, precise co-registration of dual-modal datasets, as well as for MPI-based hemodynamic functional analysis using an optical flow technique. We present the first in-vivo results of a new methodology, allowing for fast, non-invasive, quantitative and in situ hybrid cardiovascular assessment, showing its potential for future clinical applications.

Characterization of a preclinical PET insert in a 7 tesla MRI scanner: beyond NEMA testing.

This study evaluates the performance of the Bruker positron emission tomograph (PET) insert combined with a BioSpec 70/30 USR magnetic resonance imaging (MRI) scanner using the manufacturer acceptance protocol and the NEMA NU 4-2008 for small animal PET. The PET insert is made of 3 rings of 8 monolithic LYSO crystals (50 × 50 × 10 mm3) coupled to silicon photomultipliers (SiPM) arrays, conferring an axial and transaxial FOV of 15 cm and 8 cm. The MRI performance was evaluated with and without the insert for the following radiofrequency noise, magnetic field homogeneity and image quality. For the PET performance, we extended the NEMA protocol featuring system sensitivity, count rates, spatial resolution and image quality to homogeneity and accuracy for quantification using several MRI sequences (RARE, FLASH, EPI and UTE). The PET insert does not show any adverse effect on the MRI performances. The MR field homogeneity is well preserved (Diameter Spherical Volume, for 20 mm of 1.98 ± 4.78 without and -0.96 ± 5.16 Hz with the PET insert). The PET insert has no major effect on the radiofrequency field. The signal-to-noise ratio measurements also do not show major differences. Image ghosting is well within the manufacturer specifications (<2.5%) and no RF noise is visible. Maximum sensitivity of the PET insert is 11.0% at the center of the FOV even with simultaneous acquisition of EPI and RARE. PET MLEM resolution is 0.87 mm (FWHM) at 5 mm off-center of the FOV and 0.97 mm at 25 mm radial offset. The peaks for true/noise equivalent count rates are 410/240 and 628/486 kcps for the rat and mouse phantoms, and are reached at 30.34/22.85 and 27.94/22.58 MBq. PET image quality is minimally altered by the different MRI sequences. The Bruker PET insert shows no adverse effect on the MRI performance and demonstrated a high sensitivity, sub-millimeter resolution and good image quality even during simultaneous MRI acquisition.

Low-Dose Imaging in a New Preclinical Total-Body PET/CT Scanner.

Ionizing radiation constitutes a health risk to imaging scientists and study animals. Both PET and CT produce ionizing radiation. CT doses in pre-clinical in vivo imaging typically range from 50 to 1,000 mGy and biological effects in mice at this dose range have been previously described. [18F]FDG body doses in mice have been estimated to be in the range of 100 mGy for [18F]FDG. Yearly, the average whole body doses due to handling of activity by PET technologists are reported to be 3-8 mSv. A preclinical PET/CT system is presented with design features which make it suitable for small animal low-dose imaging. The CT subsystem uses a X-source power that is optimized for small animal imaging. The system design incorporates a spatial beam shaper coupled with a highly sensitive flat-panel detector and very fast acquisition (<10 s) which allows for whole body scans with doses as low as 3 mGy. The mouse total-body PET subsystem uses a detector architecture based on continuous crystals, coupled to SiPM arrays and a readout based in rows and columns. The PET field of view is 150 mm axial and 80 mm transaxial. The high solid-angle coverage of the sample and the use of continuous crystals achieve a sensitivity of 9% (NEMA) that can be leveraged for use of low tracer doses and/or performing rapid scans. The low-dose imaging capabilities of the total-body PET subsystem were tested with NEMA phantoms, in tumor models, a mouse bone metabolism scan and a rat heart dynamic scan. The CT imaging capabilities were tested in mice and in a low contrast phantom. The PET low-dose phantom and animal experiments provide evidence that image quality suitable for preclinical PET studies is achieved. Furthermore, CT image contrast using low dose scan settings was suitable as a reference for PET scans. Total-body mouse PET/CT studies could be completed with total doses of <10 mGy.

Hybrid external iliac selective endarterectomy surgical technique and outcomes.

OBJECTIVE: Long or multisegmental external iliac-to-femoral arterial lesions treated by angioplasty and stenting have achieved disappointing results. Conventional, open approaches are often complicated by significant morbidity, and endovascular stenting alone typically requires additional outflow procedures. We hypothesized that a hybrid approach, combining endovascular techniques with remote selective external iliac endarterectomy, produces superior outcomes in terms of patency compared with stenting alone, with minimal associated morbidity. METHODS: We performed a retrospective review of all patients having undergone hybrid-based retrograde iliofemoral endarterectomy from 2010 to 2014 at St. Joseph Mercy in Ann Arbor, Michigan. Patient demographics, presenting complaints, operative details, and complications were analyzed. Postoperative patency was assessed by comparison of ankle-brachial index values and qualitative patient improvement. Data were analyzed by way of paired Student t-test with significance defined as P < .05. RESULTS: A total of 40 limbs were intervened upon on 33 patients. In 20 limbs, the procedure was performed for critical limb ischemia (rest pain, n = 9; tissue loss/gangrene, n = 11). By TransAtlantic Inter-Society Consensus II criteria, 83% of iliac lesions were class D. A more even distribution was noted in TransAtlantic Inter-Society Consensus II classification for femoral and popliteal disease. Seventeen percent of patients had one-vessel infrageniculate runoff. In 21 limbs (54%), external iliac artery (EIA) stenting was performed at the time of procedure, 18 (46%) had common iliac artery (CIA) stenting, and 7 (18%) had a bridging stent from the CIA to EIA. The modal EIA stent diameter was 10 mm (range, 8-10 mm), modal CIA stent diameter 8 mm (range, 7-9 mm). The preintervention ankle-brachial index was 0.45 ± 0.24 (n = 33 limbs) and significantly improved to 0.75 ± 0.27 (n = 29 limbs; P < .001). In addition, preintervention toe pressure of 34 ± 28 (n = 28 limbs) improved to 58 ± 26 (n = 23 limbs; P < .001). No intraoperative complications occurred, which necessitated abdominal or retroperitoneal exposure. Average follow-up after the intervention was 13 ± 14.6 months. One limb (3%) required an additional outflow bypass. The incidence of ipsilateral hypogastric occlusion increased from 35% to 55% postoperatively; however, no patients reported pelvic or buttock ischemia. One patient who had the procedure done bilaterally presented 655 days after the procedure with bilateral iliac artery thrombosis and underwent aortobifemoral bypass. No other patient needed subsequent primary assisted patency or additional infrainguinal revascularization. CONCLUSIONS: Hybrid-based external iliac and femoral endarterectomy provides a minimally invasive approach to EIA occlusive disease comparable with aortofemoral bypass. Dramatic inflow improvement was observed in our series, and the need for additional outflow revascularization was minimal. The procedure was deemed technically feasible and safe, with a low number of adverse sequela and excellent primary patency achieved more than 1 year after the intervention.

Magnetic Particle Imaging: A Resovist Based Marking Technology for Guide Wires and Catheters for Vascular Interventions.

Magnetic particle imaging (MPI) is able to provide high temporal and good spatial resolution, high signal to noise ratio and sensitivity. Furthermore, it is a truly quantitative method as its signal strength is proportional to the concentration of its tracer, superparamagnetic iron oxide nanoparticles (SPIOs), over a wide range practically relevant concentrations. Thus, MPI is proposed as a promising future method for guidance of vascular interventions. To implement this, devices such as guide wires and catheters have to be discernible in MPI, which can be achieved by coating already commercially available devices with SPIOs. In this proof of principle study the feasibility of that approach is demonstrated. First, a Ferucarbotran-based SPIO-varnish was developed by embedding Ferucarbotran into an organic based solvent. Subsequently, the biocompatible varnish was applied to a commercially available guidewire and diagnostic catheter for vascular interventional purposes. In an interventional setting using a vessel phantom, the coating proved to be mechanically and chemically stable and thin enough to ensure normal handling as with uncoated devices. The devices were visualized in 3D on a preclinical MPI demonstrator using a system function based image reconstruction process. The system function was acquired with a probe of the dried varnish prior to the measurements. The devices were visualized with a very high temporal resolution and a simple catheter/guide wire maneuver was demonstrated.

System Characterization of a Highly Integrated Preclinical Hybrid MPI-MRI Scanner.

Magnetic particle imaging (MPI) is a novel tracer-based in vivo imaging modality allowing quantitative measurements of the spatial distributions of superparamagnetic iron oxide (SPIO) nanoparticles in three dimensions (3D) and in real time using electromagnetic fields. However, MPI lacks the detection of morphological information which makes it difficult to unambiguously assign spatial SPIO distributions to actual organ structures. To compensate for this, a preclinical highly integrated hybrid system combining MPI and Magnetic Resonance Imaging (MRI) has been designed and gets characterized in this work. This hybrid MPI-MRI system offers a high grade of integration with respect to its hard- and software and enables sequential measurements of MPI and MRI within one seamless study and without the need for object repositioning. Therefore, time-resolved measurements of SPIO distributions acquired with MPI as well as morphological and functional information acquired with MRI can be combined with high spatial co-registration accuracy. With this initial phantom study, the feasibility of a highly integrated MPI-MRI hybrid systems has been proven successfully. This will enable dual-modal in vivo preclinical investigations of mice and rats with high confidence of success, offering the unique feature of precise MPI FOV planning on the basis of MRI data and vice versa.

On the formulation of the image reconstruction problem in magnetic particle imaging.

In magnetic particle imaging (MPI), the spatial distribution of magnetic nanoparticles is determined by applying various static and dynamic magnetic fields. Due to the complex physical behavior of the nanoparticles, it is challenging to determine the MPI system matrix in practice. Since the first publication on MPI in 2005, different methods that rely on measurements or simulations for the determination of the MPI system matrix have been proposed. Some methods restrict the simulation to an idealized model to speed up data reconstruction by exploiting the structure of an idealized MPI system matrix. Recently, a method that processes the measurement data in x-space rather than frequency space has been proposed. In this work, we compare the different approaches for image reconstruction in MPI and show that the x-space and the frequency space reconstruction techniques are equivalent.

Outcomes of carotid endarterectomy under general and regional anesthesia from the American College of Surgeons' National Surgical Quality Improvement Program.

OBJECTIVE: Despite multiple studies over more than 3 decades, there still is no consensus about the influence of anesthesia type on postoperative outcomes following carotid endarterectomy (CEA). The objective of this study was to investigate whether anesthesia type, either general anesthesia (GA) or regional anesthesia (RA), independently contributes to the risk of postoperative cardiovascular complications or death using the American College of Surgeons' National Surgical Quality Improvement Program (ACS NSQIP) database. METHODS: Retrospective analysis of elective cases of CEA from 2005 through 2009 was performed. A propensity score model using 45 covariates, including demographic factors, comorbidities, stroke history, measures of general health, and laboratory values, was used to adjust for bias and to determine the independent influence of anesthesia type on postoperative stroke, myocardial infarction (MI), and death. RESULTS: Of 26,070 cases listed in the ACS NSQIP database, GA and RA were used in 22,054 (84.6%) and 4016 (15.4%) cases, respectively. Postoperative stroke, MI, and death occurred in 360 (1.63%), 133 (0.6%), and 154 (0.70%) patients of the GA group, respectively, and in 58 (1.44%), 11 (0.27%), and 27 (0.67%) patients of the RA group, respectively. Stratification by propensity score quintile and adjustment for covariates demonstrated GA to be a significant risk factor for postoperative MI with an adjusted odds ratio (OR) and confidence interval (CI) of 2.18 (95% CI, 1.17-4.04), P = .01 in the entire study population. The OR for MI was 5.41 (95% CI, 1.32-22.16; P = .019) in the subgroup of patients with preoperative neurologic symptoms, and 1.44 (95% CI, 0.71-2.90; P = .31) in the subgroup of patients without preoperative neurologic symptoms. CONCLUSIONS: This analysis of a large, prospectively collected and validated multicenter database indicates that GA for CEA is an independent risk factor for postoperative MI, particularly in patients with preoperative neurologic symptoms.

Strategies to distinguish benign paroxysmal positional vertigo from rotational vertebrobasilar ischemia.

Vertigo provoked by head rotation is a classic symptom of rotational vertebrobasilar ischemia (RVBI). Inner ear disease can cause positional vertigo and mimic RVBI. We review the case of a patient with vertigo consistently triggered by leftward head rotation when supine. Computed tomography angiogram and dynamic arteriogram failed to show compression of the vertebral arteries with head rotation. Further evaluation revealed benign paroxysmal positional vertigo (BPPV) as the underlying etiology. Treatment of her BPPV led to complete resolution of her symptoms. A succinct overview of this common otologic disorder is provided, and strategies to help distinguish it from RVBI are discussed.

Endovascular repair of a penetrating thoracic aortic ulcer by way of the carotid artery.

INTRODUCTION: Endovascular repair of thoracic aortic lesions offers an attractive alternative to traditional open repair. Access to the thoracic aorta can occasionally be challenging because of large device size and vessel tortuosity. Traditional access by way of the femoroiliac vessels might not be possible in the setting of synchronous iliac occlusive disease. MATERIALS AND METHODS: A 63-year-old woman presented with a 7.1-cm symptomatic, penetrating ulcer of the descending thoracic aorta. The patient's severe pulmonary disease prohibited an open repair. A Talent endoprosthesis was placed under compassionate use with approval of the institutional review board. The graft was placed by way of the left common carotid artery because of severe iliac occlusive disease. RESULTS: The thoracic endograft was successfully placed with exclusion of the pseudoaneurysm. The patient's chest pain resolved immediately. She developed mild left-sided weakness from a postoperative right anterior cerebral artery stroke that quickly resolved. The patient was discharged on postoperative day 5. No aortic endoleak was noted on follow-up computerized tomography scan at 1 month. CONCLUSIONS: Endovascular repair should be considered in patients with thoracic aortic aneurysms, particularly those with severe medical comorbidities. Placement by way of the common carotid artery is technically feasible in the setting of synchronous aortoiliac disease.

1H detected (13)C echo planar imaging.

Cyclic J cross polarisation (CYCLCROP) is a sensitive method for the noninvasive monitoring of (13)C distributions and fluxes. The PRAWN rotating frame Hartmann-Hahn mixing sequence ameliorates problems associated with sensitivity to Hartmann-Hahn mismatch and reduces RF power deposition. The combination of CYCLCROP with echo planar imaging (EPI) for spatial encoding of the proton detected carbon signal allows efficient use of the available signal to be made, permitting a significant improvement in the temporal resolution of any study. We report here on some initial experiments to demonstrate the feasibility of echo planar proton detected (13)C imaging using CYCLCROP based upon the PRAWN module, including the application of the technique to the measurement of transport and accumulation of (13)C-labelled sucrose in a castor bean seedling. Two methods that can be used to eliminate the effect of the J-splitting in the EP images are presented. In addition, a fast, image-based B(1) field-mapping method which may be used to quantitatively map the low frequency RF field in a dual resonant ((13)C/(1)H) probe is presented. The technique utilises the above described imaging method, permitting fully quantitative, 64x64 axial field maps to be generated in about a minute.