[Breathing disorders during sleep: current developments].

OBJECTIVE: Young children with congenital cardiac defect and airway obstruction leading to ventilator dependency present a significant clinical challenge with uncertain outcome. DESIGN: Retrospective review of our experience with self-expanding metal stents in these young children between 1996-2000. RESULTS: Airway stenting has been undertaken in five such children (four boys, one girl) at our institution. Their mean age was 7.4 months (range 2-14 months), and four of the five had undergone congenital cardiac surgery and could not be weaned from the ventilator following surgery. These five children were ventilator dependent for a mean of 112 days (range 40-210 days, median 71). A total of ten self-expanding metal stents were inserted (4-11 mm in diameter and 15-33 mm in length). The sites stented included the trachea (two stents), the left main bronchus (three stents) and the bronchus intermedius (five stents). Four of these five children were successfully weaned from the ventilator and extubated after a mean time interval of 6 days (range 2-11 days, median 5.5) after stenting. One child failed to wean from the ventilator, required tracheostomy and is ventilator dependent after 8 months. There was one death 2 months after extubation but unrelated to the airway. Three children remain well and asymptomatic 24, 36 and 54 months after stenting. CONCLUSIONS: Airway stenting in such young children is an infrequent procedure often undertaken in dire circumstances. We have found it valuable in enabling ventilator-dependent children to be extubated with encouraging early results. Their long-term outlook remains uncertain and is dependent on the underlying cardiac status.

Airway Obstruction↗

PubMed2002

Combined MR proton lung perfusion/angiography and helium ventilation: potential for detecting pulmonary emboli and ventilation defects.

Three-dimensional (3D) perfusion imaging allows the assessment of pulmonary blood flow in parenchyma and main pulmonary arteries simultaneously. MRI using laser-polarized (3)He gas clearly shows the ventilation distribution with high signal-to-noise ratio (SNR). In this report, the feasibility of combined lung MR angiography, perfusion, and ventilation imaging is demonstrated in a porcine model. Ultrafast gradient-echo sequences have been used for 3D perfusion and angiographic imaging, in conjunction with the use of contrast agent injections. 2D multiple-section (3)He imaging was performed subsequently by inhalation of 450 ml of hyperpolarized (3)He gas. The MR techniques were examined in a series of porcine models with externally delivered pulmonary emboli and/or airway occlusions. With emboli, perfusion deficits without ventilation defects were observed; airway occlusion resulted in matched deficits in perfusion and ventilation. High-resolution MR angiography can unambiguously reveal the location and size of the blood emboli. The combination of the three imaging methods may provide complementary information on abnormal lung anatomy and function.

Airway Obstruction↗