Impact of respiratory syncytial virus infection on surgery for congenital heart disease: postoperative course and outcome

OBJECTIVES

a) To describe the postoperative course and outcome of cardiac surgery in children with recent respiratory syncytial virus (RSV) infection; and b) to evaluate whether timing of surgery has any impact on the outcome.

DESIGN

Retrospective case series.

SETTING

Intensive care unit and medical and surgical wards of a teaching pediatric hospital.

PATIENTS

Twenty-five children (aged 25 days to 3.5 yrs; median, 4 months) with congenital heart disease who had cardiac surgery within 6 months after RSV infection.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We reviewed the clinical course and outcome of all patients. The cardiac diagnoses included ventricular septal defect (n = 11), tetralogy of Fallot (n = 3), atrioventricular canal (n = 3), and others (n = 8). Thirteen patients had surgery during the same admission as RSV infection (group I), and 12 patients had surgery electively after being discharged to home after RSV infection (group II). Two patients in group I died; both of these patients had undergone total repair of tetralogy of Fallot within 2 wks after admission for RSV infection. Postoperative complications in group I patients included pulmonary hypertension (n = 5), adult respiratory distress syndrome (n = 1), tracheal stenosis (n = 1), left ventricular dysfunction (n = 1), pericardial effusion (n = 1), secondary bacterial or fungal infection (n = 7), and deep venous thrombosis (n = 1). Of all group I patients, the ones who were operated on early appeared to be at higher risk for complications, especially for postoperative pulmonary hypertension. No patient in group II died, and only two patients had minor complications (one had reactive airway disease, and the other had a transient superior vena cava syndrome after a bidirectional Glenn operation).

CONCLUSIONS

Cardiac surgery performed during the symptomatic period of RSV infection is associated with a high risk of postoperative complications, especially postoperative pulmonary hypertension. These complications appeared to be more frequent and of greater severity in patients who had earlier surgery compared with those who had later surgery. More studies are needed regarding the proper timing of cardiac surgery in patients with congenital heart disease and RSV infection.

Automated calculation of the centerline of the human colon on CT images

RATIONALE AND OBJECTIVES

This article presents an evaluation of an automated technique for determining the colon centerline with computed tomographic (CT) data sets.

MATERIALS AND METHODS

The technique proceeds as follows. After indication of a voxel in the rectum, voxels corresponding to air were segmented. Points along the colon centerline were estimated on the basis of centers of mass of grown voxels. A second segmentation and centerline calculation was initiated at the cecum. These two centerlines were then averaged. The resulting average was refined by using lumen data obtained perpendicular to the average centerline. The accuracy of the technique was investigated with simulation phantoms. The technique was also evaluated for 40 clinical colon cases. Calculated centerline points were compared with those indicated by radiologists for a randomly selected clinical case.

RESULTS

In the simulation studies, the calculated centerline points were, on average, within 2.5 mm of the true centerlines but differed by up to 4 mm in regions of deep folds or sharp turns. In the clinical colon study, 40% of the centerlines were computed with a single seed point and 25% with two seed points. Average centerlines were computed in 1 minute. The root mean square difference between the computed centerline points and those indicated by the radiologists was 4-5 mm (comparable to interobserver variations).

CONCLUSION

Accurate centerlines can be determined from colon CT data with this automated technique.

CT colonography with three-dimensional problem solving for detection of colonic polyps

OBJECTIVE

We performed CT colonography in patients referred for conventional colonoscopy, interpreted the axial images, and used commercially available software to reconstruct endoluminal perspective views to differentiate polyps from folds.

SUBJECTS AND METHODS

We prospectively examined 44 patients (27 men and 17 women; mean age, 58 years old) with CT colonography by interpreting the axial images and using three-dimensional rendering for problem solving only. The CT scans were interpreted by two radiologists who were unaware of patients' histories as revealed by colonoscopic findings. The findings on colonography were compared with those of conventional colonoscopy to determine sensitivity, specificity, time spent on interpretation, and confidence of interpretation.

RESULTS

Colonoscopy showed normal findings in 28 patients and 22 polyps in the remaining 16 patients. Six polyps were 8 mm or larger, three were 5-7 mm, and 13 were 5 mm or smaller. The findings of the two observers revealed an overall sensitivity of 50% and 38%, respectively, and a specificity of 93% and 86%, respectively. Sensitivity for polyps larger than 8 mm was 83% and specificity was 100% for both observers. The average amount of time spent on interpretation was 28 min 30 sec (range, 14-65 min). Both observers used the endoluminal view for differentiating folds from polyps in 23 (52%) of 44 patients, which had only minimal impact on interpretation time.

CONCLUSION

CT colonography can be performed and the images interpreted using currently available hardware and software by initially using the axial images to search for polyps of significant size. Endoluminal views should be used only when necessary to help distinguish normal folds from fixed raised lesions that are suggestive of polyps.

Transcatheter closure of secundum atrial septal defect in a patient with dextrocardia using the amplatzer septal occluder

Transcatheter closure of secundum atrial septal defects (ASD) in patients with levocardia is performed routinely using various investigational devices. A 6-yr-old child with dextrocardia, situs inversus, and secundum ASD measuring 13 mm by TEE underwent successful transcatheter closure using a 15 mm Amplatzer Septal Occluder with complete closure of the defect.