Because anti-AChR antibodies are highly specific for MG and are pathogenic, dsRNA-signaling activation could contribute to the etiology of MG.

Eighty-two consecutive patients with interrupted aortic arch were referred to our institution between 1985 and 1995. Three died before any attempt at operation and 79 underwent surgical repair. Median age at operation was 9 days (range 1 day to 6 years) and median weight was 3.0 kg (range 1.8 to 20 kg). All but one were in severe congestive heart failure and 31.5% had oliguria or anuria. Preoperative pH varied between 6.8 and 7.4 (median 7.3). Sixty-nine received prostaglandin E1 infusion and 54 received mechanical ventilation. Aggressive preoperative ressucitation was necessary in 43 cases. Preoperative transfontanellar echography (performed routinely) since 1987 revealed intracerebral bleeding in six patients. Type A interrupted aortic arch was present in 37 cases, 41 patients had type B, and one had type C. Interrupted aortic arch was associated with single ventricular septal defect in 35 cases, 24 patients had associated complex heart defects, and 30 had significant subaortic stenosis (six had both subaortic stenosis and complex association). Aortopulmonary window was found in four patients, truncus arteriosus was found in eight, and transposition of the great arteries was found in five, double-outlet right ventricle was found in one, single ventricle was found in three, multiple ventricular septal defects were found in two and superior-inferior ventricles were found in one. Sixty-four patients underwent single-stage repair and 15 underwent multistage repair. Aortic arch repair consisted of direct anastomosis in 59 cases, patch augmentation in eight, and conduit interposition in 12. Ten patients underwent associated pulmonary artery banding and 19 underwent concomitant repair of complex associated lesions. The subaortic stenosis was addressed by four surgical techniques: myotomy or myectomy in five patients; creation of a double-outlet left ventricle, aortopulmonary anastomosis, and conduit insertion between the right ventricle and pulmonary artery bifurcation in four; no direct attempt to relieve the subaortic stenosis in six; and left-sided ventricular septal defect patch in 15. Mean duration of deep hypothermic circulatory arrest, crossclamp time, and cardiopulmonary bypass time were 38.8 +/- 15.6 min, 60.5 +/- 24.7 min, and 143 +/- 40.1 min, respectively. Postoperative mortality rate was 18.9% (70% confidence limits 14% to 24.6%), and overall mortality rate was 31% (70% confidence limits 20.9% to 42.2%). The results have improved with time, with an overall operative mortality rate of 12% since 1990. Univariate statistical analysis revealed that early survival was influenced by preoperative renal function, detection of cerebral bleeding by transfontanellar echography, the number of cardioplegic injections, and the date of operation. Multivariate analysis revealed that preoperative renal function and the number of cardioplegic injections were independent risk factors for early mortality. Echocardiographic measurements of the left heart-aorta complex with preoperative Z values as low as-4 demonstrated rapid ...

No abstract

Three groups of unusual forms of tracheobronchial compression caused by vascular anomalies are presented. Three patients had an encircling right aortic arch with a left-sided descending aorta and ligamentum arteriosum (group 1), two patients had airway compression caused by a pincer effect between a malposed and enlarged ascending aorta and the descending aorta (group 2), and three patients had airway compression after an arterial switch operation for transposition of the great arteries (group 3). Symptoms developed in all patients before the age of 4 months, and six of them had multiple failed attempts at extubation before the surgical intervention directed at relieving the airway compression. Fiberoptic endoscopy was used in all patients as a first-line diagnostic tool and was 100% accurate in establishing the diagnosis. The operations performed were aortic uncrossing in group 1, dissection and aortopexy of the right or left main bronchus in group 2, and dissection of the left main bronchus and lysis of adhesions in group 3. In group 1 there was one early death, resulting from aspiration, and one late death 4 years later, resulting from an unrelated cause. In this group, bronchomalacia was noted after the operation and resolved gradually in the year after the intervention. In group 2, one patient died of an aortobronchial fistula after placement of a bronchial stent. Group 3 patients had good postoperative results. Two of them are completely symptom-free and one has residual bronchomalacia and may need placement of a bronchial stent.

The aortic arch repair associated with pulmonary autograft patch augmentation resulted in superior midterm outcomes and therefore constitutes a reliable alternative to the direct anastomosis technique. It allowed complete relief of anatomic afterload and diminished the anastomotic tension, thus reducing the risk of restenosis and tracheobronchial compression. We observed a significantly higher rate of recurrence after patch aortoplasty with other materials.