3D volume-selective turbo spin echo for carotid artery wall imaging with navigator detection of swallowing

PURPOSE: To improve 3D volume-selective turbo spin echo (TSE) carotid artery wall imaging by incorporating navigators to reduce artifacts caused by swallowing. MATERIALS AND METHODS: Images were acquired on a Siemens Magnetom Sonata 1.5T scanner. 3D volume-selective TSE scans of the carotid arteries were acquired in six healthy volunteers. A cross-pair navigator placed on the back of the tongue was used to detect swallowing and movement. Two swallowing patterns were tested: 1) a single swallow approximately halfway through the scan time, at the center of k(z), and 2) repeated swallowing as often as possible throughout the scan period. Images were acquired with and without navigators for comparison. Signal intensity in the lumen was quantified for the quality of blood suppression, and the clarity of the vessel wall in the common carotid was ranked by four independent blinded observers. RESULTS: In general, lower signal intensity was recorded in the lumen, and decreased blurring and ghosting were observed on scans with navigator control. This reduction in lumen signal intensity signifies an improvement in the black-blood imaging technique. The differences likely reflect the improved double inversion/blood suppression efficiency due to cycles being rejected when the heart rate changed at the point of swallowing, or decreased motional blurring/ghosting of tissue when the navigator is used, or a combination of these two effects. A statistical analysis of image quality showed a significant difference between navigated and non-navigated scans as scored by four independent, blinded observers. For both swallowing patterns, the mean score for the navigator images was on average 0.6 greater than that of non-navigator images (on a scoring scale of 0-5, where 0 = no vessel visible, and 5 = good delineation and blood suppression) and P-values for all observers were less than 0.01. Overall, the central swallow scans were scored higher than the repeated swallow scans. One reason for this may be the fact that the heart rate increased on swallowing, and this often lasted for one or two cardiac cycles after the navigator returned to the normal acceptance position. The effect of the increased heart rate after swallowing is likely to have an effect on double inversion blood suppression efficiency. Therefore, the increased amount of heart rate changes with repeated swallowing may have a greater adverse effect, even if the navigator rejects data views during the swallowing motion. CONCLUSION: The clarity of vessel wall delineation and the apparent efficiency of blood suppression are reduced by swallowing during acquisition. Both motion blurring and quality of blood suppression are factors that can be improved with the use of a navigator accept/reject method.     

Sleeve lobectomy (lobectomy and bronchoplasty) for bronchial carcinoma

We present a series of 90 patients who underwent sleeve lobectomy for malignant bronchial tumors at the Brompton Hospital, London, between 1964 and 1974. The operative mortality was low (1%), and technical complications were infrequent. Bronchial stenosis, which occurred in 6% of patients, was due to recurrence of tumor in 4% and cicatrization in 2%. The majority of patients had squamous cell carcinomas of the upper lobe (76/90). In this group, the 5-year survival was 71% when the hilar lymph nodes were clear of tumor at the time of operation and 17% when the hilar lymph nodes were involved. Because these 5-year survival figures suggest that tumor-free survival is not significantly compromised by this conservative approach, we believe that sleeve lobectomy rather than pneumonectomy should be considered the operation of choice for squamous cell carcinomas of the upper lobe orifice involving the main bronchus.     

Direct complications of repeat median sternotomy in adults

Whilst the potential risk to underlying vital structures from redo-sternotomy is well recognized, the actual risk is poorly quantified. Our aim was to determine the incidence of complications directly attributable to redo-sternotomy and to ascertain whether the use of femoro-femoral CPB (FF) prior to redo-sternotomy alters operative morbidity and mortality. Case notes of 185 patients undergoing cardiac surgery necessitating redo-sternotomy between May 1998 and November 2002 were reviewed. Of 121 males and 64 females, the median age was 65.5 years (range 60.1-75 years). Elective FF was performed in 71 (38.3%) of cases and 114 (60%) were performed without the aid of prior femoro-femoral CPB (WFF). Three (1.6%) patients initially planned for WFF were converted to emergency FF due to serious complications. Complications directly attributable to redo-sternotomy occurred in 21 (11.3%) cases; 12 (16.9%) in the FF group and 9 (5.3%) in the WFF group. Overall mortality was 1.6%. In summary, our results suggest that morbidity risk for the operation increases significantly with redo-sternotomy alone. Three deaths in our series from direct complications attributable to redo-sternotomy signify an added risk. Hence the necessity for careful surgical technique and judicious use of elective FF-CPB is emphasized.     

Venovenous extracorporeal membrane oxygenation for respiratory failure in inotrope dependent neonates

It is often stated that venovenous extracorporeal membrane oxygenation (VV ECMO) should not be used in inotrope dependent patients. It is our practice to use VV ECMO in most patients with respiratory failure even though many of these patients are receiving significant doses of inotropes. Our objective was to review the mode of ECMO in relation to precannulation doses of inotropes administered to neonates treated with ECMO for respiratory failure. Forty-three consecutive case notes were reviewed. Data were collected for basic demographic and ECMO parameters. Inotropic doses were converted to a single score for ease of comparison, with one point equivalent to 1 microg/kg/min dopamine. Forty-three neonates were studied; 37(86%) were treated with VV ECMO and 6 (14%) were treated with VA ECMO. Significant pre-ECMO inotropic support (score > 10) was present in 30 (70%) of the 43 cases. Of these patients, 26 were treated via VV ECMO with a survival rate of 84%, while 4 were treated with VA ECMO with a survival of 75%. Inotrope scores fell to nonsignificant levels (< 10) within 24 hours, regardless of ECMO mode. Mean arterial blood pressure remained above precannulation levels in both groups. VV ECMO allows safe treatment of neonatal respiratory failure in the presence of significant inotropic support. We recommend VV ECMO for neonatal respiratory failure in all cases except where double lumen cannulation is impossible or when septic shock is refractory to inotropic support (i.e., mean blood pressure < 35 mm Hg despite inotrope score of > 100).     

The incidence and characteristics of neonatal irreversible lung dysplasia

A 3-year retrospective study of 173 neonates treated with extracorporeal membrane oxygenation in the United Kingdom identified 9 cases of irreversible lung dysplasia, including alveolar capillary dysplasia (n = 5), surfactant protein B deficiency (n = 1), pulmonary hypoplasia (n = 1), pulmonary lymphangiectasis (n = 1), and combined lymphangiectasis and hypoplasia (n = 1).     

Coronary artery anomalies: assessment with free-breathing three-dimensional coronary MR angiography

PURPOSE: To evaluate a simplified protocol by using free-breathing three-dimensional (3D) coronary magnetic resonance (MR) angiography to determine the anatomy of anomalous coronary arteries, in particular the relationship of the vessels to the aortic root. MATERIALS AND METHODS: Twenty-six patients (18 men, eight women; mean age, 50 years; age range, 18-77 years) who had a history of chest pain, palpitations, or syncope and who were suspected of having coronary artery anomalies were examined with free-breathing MR angiography. Multiple 3D volume slabs were acquired at the level of the sinuses of Valsalva by using diaphragmatic navigators for respiratory artifact suppression. The proximal anatomy of the coronary arteries was determined. RESULTS: Six anomalous circumflex arteries originated from the right sinus of Valsalva and passed behind the aortic root. Six right coronary arteries arose from the left sinus of Valsalva and coursed between the aortic root and the right ventricular outflow tract (RVOT). Nine left coronary arteries arose from the right sinus of Valsalva; seven of nine coursed between the aortic root and the RVOT. Five patients had minor anomalies. Overall, in eight patients with anomalous arteries that coursed between the aortic root and the RVOT, conventional coronary angiography could not be used confidently to identify the proximal course. CONCLUSION: Free-breathing 3D coronary MR angiography can be used to identify the proximal anatomy of anomalous coronary arteries.