Michael A. Winkler

Abdominal compartment syndrome associated with endovascular and open repair of ruptured abdominal aortic aneurysms

BACKGROUND Abdominal compartment syndrome (ACS) is a known complication of ruptured abdominal aortic aneurysm (rAAA) repair and can occur with either endovascular (EVAR) or open repair. We hypothesize that the underlying mechanism for the development of ACS may differ for patients treated with EVAR or open operation. METHODS All patients who presented with rAAA at a tertiary care medical center between January 2005 and December 2010 were included in the study. Demographic factors, type of repair (open vs EVAR), development of ACS, intraoperative and postoperative fluid requirements, estimated blood loss, length of stay, and morbidity and mortality were recorded. Student t-test and Fisher exact test were performed. A P value < .05 was considered significant. RESULTS Seventy-three patients, 62 men and 11 women with an average age of 70.5 years, were treated for rAAA. Forty-four (60%) underwent open repair; 29 (40%) had EVAR. Overall mortality was 42% (31 of 73), with mortality being 31% (9 of 29) in EVAR and 48% (21 of 44) in open repair. ACS developed in 21 patients (29%), more frequently in open repair than in EVAR (15 of 44 [34%] vs 6 of 29 [21%]; P = NS). Mortality was higher in patients who developed ACS compared with those without ACS (13 of 21 [62%] vs 17 of 52 [33%]; P = .022). This finding was especially pronounced in the EVAR group, in which mortality in patients with ACS was 83% (5 of 6) compared with 17% (4 of 23) without ACS (P = .005). Intraoperative fluid requirements were significantly higher in EVAR patients who developed ACS compared with those without ACS, including packed red blood cells (5600 mL vs 1100 mL; P < .0001), total blood products (9300 mL vs 1500 mL; P < .001), crystalloid (11,200 mL vs 4500 mL; P < .001), and estimated blood loss (5000 mL vs 660 mL; P = .006). In patients treated with open repair, there were no significant differences in intraoperative fluid requirements between those who developed ACS and those without ACS. However, patients who developed ACS after open repair required significantly more crystalloid on the first and second postoperative days (first postoperative day, 8300 mL vs 5600 mL [P = .01]; second postoperative day, 6500 mL vs 3800 mL [P = .004]). CONCLUSIONS This study demonstrates that the development of ACS after repair of rAAA is associated with increased mortality, especially in EVAR-treated patients. The higher intraoperative blood and blood product requirements associated with ACS in EVAR patients suggest that one potential cause of early ACS is continued hemorrhage from lumbar and inferior mesenteric vessels through the ruptured aneurysm sac. Hence, open ligation of such vessels should be considered in patients developing early ACS after EVAR for rAAA.

Training, competency, and certification in cardiac CT: A summary statement from the Society of Cardiovascular Computed Tomography

Training and competency criteria in cardiac CT were developed to guide practitioners in the process of achieving and maintaining skills in performing and interpreting cardiac CT studies. Appropriate training and eventual certification in cardiac CT angiography may be obtained by adhering to the recommendations for competency as set forth by either the American College of Cardiology Foundation (ACCF) or the American College of Radiology (ACR). Competency under either pathway requires both knowledge and experience-based components, with benchmarks set for level of experience on the basis of the extent of training experience. Although these recommended parameters are substantial, meeting these training criteria does not guarantee competence or expertise, which is the responsibility of the individual practitioner and may require further training and experience. Separate from satisfying initial training for the achievement of competency, certification in cardiac CT may be achieved through formal certification under the Certification Board of Cardiovascular Computed Tomography. Eligibility for certification generally follows the ACCF/American Heart Association Level 2 or ACR competency pathways. The ACR also conducts a certificate program related to advanced proficiency in cardiac CT. This official document of the Society of Cardiovascular Computed Tomography summarizes the present criteria for competency and certification in the field of cardiac CT.

Congenital bicuspid aortic valve first presenting as an aortic aneurysm.

PRESENTATION When evaluating patients with bicuspid aortic valves, it is important not to overlook the potential non-valvular pathology often associated with this common condition, which can have devastating consequences if not recognized early. Bicuspid aortic valves are the most common congenital heart defects occurring in the US population, and their associated aortic pathology is not mutually exclusive. A constant awareness of the aortopathy associated with bicuspid aortic valves should exist, because the aortic involvement can progress out of proportion to the underlying aortic valvular disease and even require surgical intervention without repair to the aortic valve itself being required. The pathophysiology involved with aortic enlargement in patients with bicuspid aortic valve has been debated intensely, with embryologic error and hemodynamic flow disturbance in some combination thought to be the likely culprits. Recognition of the key elements in this bicuspid aortic valve aortopathy syndrome of having a hemodynamically normal bicuspid aortic valve and an enlarged ascending aorta should lead to a more careful evaluation of the aorta irrespective of bicuspid aortic valve stenosis or regurgitation severity. To illustrate these points, we present the case of an asymptomatic 42-year-old white man with no significant medical history who received a transthoracic echocardiogram by an outside hospital provider for a murmur. He was then referred to cardiology with a new diagnosis of a bicuspid aortic valve and suspected ascending aortic aneurysm. A cardiac computed tomography scan was performed to better assess the size of this aneurysm and to confirm the absence of an associated coarctation. The ascending aortic aneurysm was 4.2 4.3 cm in maximal dimension. There was no aortic coarctation.

Identification of Coronary Artery Calcification and Diagnosis of Coronary Artery Disease by Abdominal CT : A Resident Education Continuous Quality Improvement Project

RATIONALE AND OBJECTIVES Coronary artery calcium (CAC) scoring is an excellent imaging tool for subclinical atherosclerosis detection and risk stratification. We hypothesize that although CAC has been underreported in the past on computed tomography (CT) scans of the abdomen, specialized resident educational intervention can improve on this underreporting. MATERIALS AND METHODS Beginning July 2009, a dedicated radiology resident cardiac imaging rotation and curriculum was initiated. A retrospective review of the first 500 abdominal CT reports from January 2009, 2011, and 2013 was performed including studies originally interpreted by a resident and primary attending physician interpretations. Each scan was reevaluated for presence or absence of CAC and coronary artery disease (CAD) by a cardiovascular CT expert reader. These data were then correlated to determine if the presence of CAC had been properly reported initially. The results of the three time periods were compared to assess for improved rates of CAC and CAD reporting after initiation of a resident cardiac imaging curriculum. RESULTS Statistically significant improvements in the reporting of CAC and CAD on CT scans of the abdomen occurred after the initiation of formal resident cardiac imaging training which included two rotations (4 weeks each) of dedicated cardiac CT and cardiac magnetic resonance imaging interpretation during the residents second, third, or fourth radiology training years. The improvement was persistent and increased over time, improving from 1% to 72% after 2 years and to 90% after 4 years. CONCLUSIONS This single-center retrospective analysis shows association between implementation of formal cardiac imaging training into radiology resident education and improved CAC detection and CAD reporting on abdominal CT scans.

Synthetic ECG-Gated Cardiac Computed Tomography for In Vivo Imaging of the Temporary Total Artificial Heart

To date, there have been >1000 implantations of temporary total artificial hearts (TAH-t). As expected, complications related to the use of the TAH-t can occur.1 A noninvasive imaging modality that would be capable of diagnosing mechanical failure, surgical complications, and thromboembolic phenomena related to the TAH-t is desirable. Echocardiography is not suitable to evaluate a TAH-t because ultrasound cannot penetrate air and the polyurethane components in the TAH-t assembly. Cardiac magnetic resonance imaging is likewise unsuitable because of the susceptibility to artifacts that the titanium valve components in the TAH-t would create. Conventional computed tomography (CT) is limited by motion artifact.2 Cardiac CT (CCT) can produce motion-artifact–free images of the heart. If performed with retrospective gating, CCT can also be used to acquire time-resolved images. However, CCT requires simultaneous recording of the patient’s ECG, and patients who have a TAH-t do not generate an ECG. Consequently, a variation in technique is necessary to image patients with TAH-t with this modality. Detailed below …

Prostate brachytherapy seed migration to the heart seen on cardiovascular computed tomographic angiography

Brachytherapy consists of placing radioactive sources into or adjacent to tumors, to deliver conformal radiation treatment. The technique is used for treatment of primary malignancies and for salvage in recurrent disease. Permanent prostate brachytherapy seeds are small metal implants containing radioactive sources of I-125, Pd-103, or Cs-131 encased in a titanium shell. They can embolize through the venous system to the lungs or heart and subsequently be detected by cardiovascular computed tomography. Cardiovascular imagers should be aware of the appearance of migrated seeds, as their presence in the chest is generally benign, so that unnecessary worry and testing are avoided. We report a case of a patient who underwent brachytherapy for prostate cancer and developed a therapeutic seeds embolus to the right ventricle.

The use of intraosseous needles for injection of contrast media for computed tomographic angiography of the thoracic aorta

Background The objective of this study is to evaluate the safety and quality of computed tomographic angiography of the thoracic aorta (CTA-TA) exams performed using intraosseous needle intravenous access (ION-IVA) for contrast media injection (CMI). Methods All CTA-TA exams at the study institution performed between 1/1/2013 and 8/14/2015 were reviewed retrospectively to identify those exams which had been performed using ION-IVA (ION-exams). ION-exams were then analyzed to determine aortic attenuation and contrast-to-noise ratio (CNR). Linear regression was used to determine how injection rate and other variables affected image quality for ION-exams. Patient electronic medical records were reviewed to identify any adverse events related to CTA-TA or ION-IVA. Results 17 (~0.2%) of 7401 exams were ION-exams. ION-exam CMI rates varied between 2.5 and 4 ml/s. Mean attenuation was 312 HU (SD 88 HU) and mean CNR was 25 (SD 9.9). A strong positive linear association between attenuation and injection rate was found. No immediate or delayed complications related to the ION-exams, or intraosseous needle use in general, occurred. Conclusion For CTA-TA, ION-IVA appears to be a safe and effective route for CMI at rates up to 4 ml/s.

Bleeding Stomal Varices in Portal Hypertension

We report a case of a 50-year-old man with a history of liver cirrhosis and colon cancer post end colostomy presenting to the emergency department with stomal bleeding and passage of clots into the colostomy bag. The patient was treated with transjugular intrahepatic portosystemic shunt (TIPS) and concomitant embolization of the stomal varices via the TIPS shunt using N-butyl cyanoacrylate mixed with ethiodol. Although stomal variceal bleeding is uncommon, this entity can have up to 40% mortality upon initial presentation, given the challenges in diagnosis and management. Currently, there are no established standard treatments for stomal variceal bleeding. In addition, to the best of our knowledge, there are no cases in the current literature in which treatment of this entity is performed with a combination of TIPS shunt placement and N-butyl cyanoacrylate variceal embolization.

Early TIPS failure in association with left mesenterico-gonadal spontaneous portosystemic venous shunt; a case report

Transjugular intrahepatic portosystemic shunt (TIPS) periprocedural thrombosis rates have fallen significantly since the introduction of polytetrafluoroethylene-covered stent grafts. We present a case of a cirrhotic patient with portal hypertension presenting with early TIPS thrombosis in association with an underlying competing spontaneous left mesenterico-gonadal venous shunt, an uncommon variant of spontaneous portal systemic shunt (SPSS). The patient presented with bleeding distal duodenal varices refractory to endovascular therapy, and although a successful TIPS procedure was performed for this indication, early thrombosis was determined by follow-up abdominopelvic computed tomographic angiography (CTA) scan. Despite undergoing a standard TIPS revision procedure, blood flow through the TIPS remained hepatofugal. During a TIPS revision, portal vein angiography revealed competing large inferior mesenteric vein (IMV) varices shunting into the left renal vein via the left gonadal vein. The initial abdominal CTA was later reviewed by a non-invasive cardiovascular radiologist, and the presence of the competing left mesenterico-gonadal shunt was retrospectively identified. Radiologists interpreting CTA exams should be aware of SPSS generally and mesenterico-gonadal shunts specifically. Pre-procedural knowledge of underlying SPSS can affect post procedural outcomes and should be emphasized in the final CTA report.

Intraarticular extravasation, an unusual complication of computed tomographic angiography performed with intraosseous needle intravenous access

Off label use of intraosseous needles (IONs) for contrast media (CM) injection during computed tomographic angiography (CTA) has been reported in small case series and isolated case reports. Presently, complications specific to this novel indication are essentially unknown. In this communication, we report an extravasation of CM from the intramedullary space of the humerus into the glenohumeral joint space during an ION injection of CM during a CTA of the head, neck, and chest. Although clinically insignificant in this case, a more severe intraarticular extravasation could have had both short or long term adverse sequelae. Practitioners of CTA should be aware of this potential complication.