Slide Tracheobronchoplasty for Right Mainstem Bronchial Agenesis
This is the first
report of a successful slide tracheobronchoplasty for right mainstem bronchial
agenesis in the literature.
Patient is a 2.4kg ex-36 week male (with a corrected-gestational age of 39.6 weeks at time of surgery) with an antenatal diagnosis of congenital high airway obstruction syndrome (CHAOS).
Patient was born via cesarean section at 36-week GA and 1.94kg. Patient was immediately intubated following birth due to hypoxia and absent breath sounds on the right side. Transthoracic echocardiogram demonstrated a structurally normal heart and function with suprasystemic right ventricular pressure. Chest Xray demonstrated a completely opacified right chest. Patient was managed medically and stabilized. Following stabilization, the patient underwent a bronchoscopy that confirmed the diagnosis of right mainstem bronchial agenesis at the level of the carina, terminating in a highly-vascularized membranous plate. The left mainstem bronchus and distal airway appeared to be normal. Prior to surgery, the patient underwent a chest MRI that confirmed that left lung distal airway and vasculature appeared to be normal. The right lung demonstrated normal distal bronchial pattern, reassuring volume of right lung parenchyma, and normal appearing pulmonary veins.
It was also noted on the MRI that the heart was severely displaced into the right hemithorax and the left lung had herniated past midline into the right chest. Due to the patients predicted clinical course and inevitable deterioration (increasing right ventricular pressure and increasing left pulmonary artery gradient), decision was made to take the patient to the operating room for a right-sided slide tracheobronchoplasty on Extracorporeal Membrane Oxygenation (ECMO).
Preoperative plan was to cannulate the right neck for ECMO and proceed with repair through a median sternotomy as not to be encumbered by the cannulae. This strategy was employed due to the field already being quite small and due to the rightward shift of all of the mediastinal contents. Upon exploration of the right neck, the right internal jugular vein and right carotid artery were exceptionally small and thought to be inadequate to support venoarterial ECMO cannulation.
A median sternotomy was then carried out and the right lobe of the thymus was removed. The left lung was overinflated and crossed over the midline. Pericardium was opened along the right lateral edge within 1-2cm of the phrenic nerve. Opening the pericardium in such a way made it easier to completely reduce the left lung into the left chest and also helped lift the heart closer to the midline. The ascending aorta, main pulmonary artery, and right pulmonary artery were circumferentially mobilized. Following heparinization, an 8Fr. cannula was placed into the ascending aorta (near the base of the innominate artery) as the arterial limb of the ECMO circuit. The right atrial appendage was amputated and a 10Fr. right-angle cannula was placed as the venous limb of the ECMO circuit. Venoarterial ECMO was initiated.
To enhance visualization of the right-sided atretic mainstem bronchus, the aorta was retracted to the left and the right pulmonary artery was retracted inferiorly. The approximately 5mm atretic segment was identified off of the carina. This segment was transected distally first, exposing a large amount of mucus was that cleared with a 6Fr. suction catheter. Once completed, corresponding V-shaped wedges on the trachea at the level of the carina and along the distal right-sided bronchus were excised. The trachea, left mainstem bronchus, and distal right-sided bronchus were extensively dissected and mobilized. The distal right-sided bronchus was then anastomosed to the trachea in a posterior-anterior fashion with a double-armed 6-0 polydioxanone suture.
Following tracheal repair and hemostasis, the suture line was leak-tested by submerging the repaired area in warm saline and Valsalva breaths at pressures of 10, 20, and 30cm H20. Evicel surgical adhesive was applied along the suture line following successful leak-test. Ventilation was initiated with aggressive suctioning. Both the right and left lungs aerated and appeared healthy.
Patient was successfully weaned and separated from venoarterial ECMO support without difficulty and requiring no inotropic support. Sternum was closed in normal fashion following hemostasis. Post-operative CXR demonstrated a well-aerated right and left lung. Patient was extubated on post-operative day five. Follow-up bronchoscopy demonstrated a well-healed and widely patent anastomotic site. Shortly thereafter, the patient was discharged home on no respiratory support.