Linda M. de Heer

Pulsatile Distention of the Nondiseased and Stenotic Aortic Valve Annulus: Analysis With Electrocardiogram-Gated Computed Tomography

BACKGROUND Knowledge of the dynamic changes of the aortic valve (AV) annulus may aid in the sizing and design of transcatheter valve prostheses. We assessed AV annulus distention in patients without AV disease and with severe AV stenosis (AS) using computed tomography (CT). METHODS Electrocardiogram-gated multislice CT scans of 15 patients without AV disease (age 53±12 years) and 20 patients with severe AS (age 81±6 years) were analyzed. Images in plane with the AV annulus were reconstructed for every 10% to 12.5% of the cardiac cycle. With the use of dedicated software the annulus was segmented. In all phases of the cardiac cycle the area was measured, as were the maximum radius (Rmax) and minimum radius (Rmin) of an ellipse fitted around the segmented lumen. The asymmetry ratio was defined as Rmax/Rmin. Direct comparison of both groups was not possible because age and scan protocols were confounding factors. RESULTS The mean change of the area, Rmax, and Rmin was 122±33 mm2, 1.8±0.7 mm, and 2.4±0.5 mm in the patients with nondiseased annulus and 98±52 mm2, 1.4±0.7 mm, and 1.9±0.8 mm in those with AS. The mean asymmetry ratio was 1.3±0.1, indicating an elliptic annulus. Both the asymmetry ratio and the area changed significantly over the cardiac cycle (p<0.001). CONCLUSIONS With the use of CT and postprocessing software, significant area and radius changes during the cardiac cycle were demonstrated in both the nondiseased annulus and the stenotic annulus. This finding may help selection of the optimal size in patients undergoing AV implantation and also aid in prosthesis design.

Effect of computed tomography before cardiac surgery on surgical strategy, mortality and stroke

AIM To investigate whether preoperative chest computed tomography (CT) decreases postoperative mortality and stroke rate in cardiac surgery by detection of calcifications and visualization of postoperative anatomy in redo cardiac surgery which can be used to optimize the surgical approach. METHODS The PubMed, EMBASE and Cochrane databases were searched and articles concerning preoperative CT in cardiac surgery were included. Articles not reporting mortality, stroke rate or change in surgical approach were excluded. Studies concerning primary cardiac surgery as well as articles concerning redo cardiac surgery were both included. RESULTS Eighteen studies were included (n=4057 patients) in which 2584 patients received a preoperative CT. Seven articles (n=1754 patients) concerned primary surgery and eleven articles (n=2303 patients) concerned redo cardiac surgery. None of the studies was randomized but 8 studies provided a comparison to a control group. Stroke rate decreased with 77-96% (primary surgery) and 18-100% (redo surgery) in patients receiving a preoperative CT. Mortality decreased up to 66% in studies investigating primary surgery while the effect on mortality in redo surgery varied widely. Change in surgical approach based on CT-findings consisted of choosing a different cannulation site, opting for off-pump surgery and cancellation of surgery. CONCLUSIONS Current evidence suggests that preoperative CT imaging may lead to decreased stroke and mortality rate in patients undergoing primary cardiac surgery by optimizing surgical approach. In patients undergoing redo cardiac surgery stroke rate is also decreased but the effect on mortality is unclear. However, evidence is weak and included studies were of moderate quality.

Giant left atrial appendage: a rare anomaly.

A giant left atrial appendage is a rare congenital anomaly that has been reported on only a few occasions. We report two symptomatic patients with atrial fibrillation combined with a cerebellar infarct in one and dyspnea in the other. Both patients were treated surgically with resection of the giant left atrial appendage and radiofrequency pulmonary vein isolation. Recognition of this uncommon pathology can lead to timely surgical intervention.

Multimodality imaging throughout transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is a novel, less-invasive technique used to treat selected patients with severe aortic valve stenosis with a high surgical risk. Noninvasive imaging before, during and after the procedure is of the utmost importance in this minimally invasive procedure. Screening of the patient and sizing of the aortic root by echocardiography and multislice computed tomography is of great importance to ensure success of the TAVI procedure. Echocardiography and fluoroscopy are essential during the procedure. During follow-up of the patients, echocardiography is important to evaluate the prosthesis function, durability and integrity. Additionally, multislice computed tomography and MRI might be helpful in the follow-up of selected cases. This article outlines the evolving role of multimodality imaging throughout TAVI in patients with severe aortic valve stenosis. It describes, in a stepwise approach, how multimodality imaging by echocardiography, angiography, multislice computed tomography and MRI enhances the TAVI procedure.

Computed Tomography Detects Tissue Formation in a Stented Engineered Heart Valve

Tissue-engineered heart valves (TEHV) are being explored as an alternative to conventional heart valve prostheses. Using the classic tissue engineering paradigm, a stented tri-leaflet valve is fabricated. Subsequently, the construct is implanted into the pulmonary position in a sheep. Follow-up by means of computed tomography, magnetic resonance imaging, and echocardiography was used to assess tissue formation. After 4 weeks, the scaffold of the TEHV has degraded and new tissue is formed. However, small areas without tissue formation were present at macroscopic inspection. This phenomenon was only visible on computed tomographic images. Therefore, computed tomography appears a promising technique for in vivo follow-up of tissue formation in tissue-engineered heart valves.

Frequency of abnormal findings on routine chest radiography before cardiac surgery

Objective: Preoperative chest radiograph screening is widely used before cardiac surgery. The objective of this study was to investigate the frequency of abnormal findings on a routine chest radiograph before cardiac surgery. Methods: In this retrospective cohort study, 1136 patients were included. Patients were scheduled for cardiac surgery and underwent a preoperative chest radiograph. The primary outcome was the frequency of abnormalities on the chest radiograph. Secondary outcome was the effect of those abnormalities on surgery. Results: One half of the patients (570/1136; 50%) had 1 or more abnormalities on the chest radiograph. Most frequent abnormalities were cardiomegaly, aortic elongation, signs of chronic obstructive pulmonary disease, vertebral fractures or height loss, possible pulmonary or mediastinal mass, pleural effusion, and atelectasis. In 2 patients (2/1136; 0.2%), the chest radiograph led to postponement of surgery, whereas in none of the patients the surgery was cancelled. In 1 patient (1/1136; 0.1%) the surgical approach was altered and in 15 patients (15/1136; 1.3%) further analysis was performed without having an impact on the planned surgical approach. Conclusions: Although abnormalities are frequently found on preoperative chest radiographs before cardiac surgery, change in clinical management with regard to planned surgery or surgical approach occurs infrequently.

Successful treatment of bronchial stenosis after lung transplantation

Treatment of stenotic anastomosis after lung transplantation can be challenging. In this case report, we present a case in which 3D computed tomography reconstructions guided the clinical decision towards operative bronchoplasty after which our patient was treated successfully.