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Paralysis or eventration of the diaphragm is a relatively uncommon problem in infants and children, but one that can cause significant respiratory distress. Eventration may be congenital in origin, or it may result from iatrogenic injury, either from birth trauma or from injury to the phrenic nerves during cardiac surgery. When there is significant compromise to pulmonary function, diaphragmatic plication should be considered to allow better expansion of the affected lower lobe. Both laparoscopic and thoracoscopic plication are minimally invasive approaches for dealing with this problem and significantly decrease the morbidity compared with an open approach. Initially we preferred a laparoscopic approach because the abdomen affords increased workspace. However, with greater experience, we have adopted a thoracoscopic approach unless there are significant contraindications to entering the ipsilateral chest, such as severe respiratory compromise.
Indications for Workup and Operation
The indication for operative correction is an elevated hemidiaphragm with evidence of lung compression or atelectasis, which may be segmental or lobar. The elevated diaphragm is usually associated with some degree of respiratory compromise, which can be quite severe in some patients. The goals of intervention range from an attempt to improve pulmonary function enough to allow a patient to be weaned from a ventilator to improving function enough to relieve dyspnea on exertion or an oxygen requirement. The advent of minimally invasive surgery has allowed a more liberal use of this operation.
The workup includes a routine chest radiograph that shows an elevated hemidiaphragm and mediastinal shift, as well as pulmonary function testing (in older patients) that shows a restrictive pattern. Confirmation of a paralyzed diaphragm can be obtained with ultrasound or fluoroscopy, with demonstration of paradoxical motion of the diaphragm. In some cases, it can be difficult to differentiate an eventration from a diaphragmatic hernia with a thick sac. However, these are probably variations of the same developmental defect, and they are often treated similarly.
An infant is placed supine near the foot of the bed ( Fig. 24-1 ). Larger patients are placed in stirrups so that the surgeon can stand between the legs, which allows good access to the upper abdomen and diaphragm. An orogastric tube is inserted to decompress the stomach, and the bladder is manually emptied.
The abdomen is insufflated through a 4- or 5-mm cannula inserted through an infraumbilical ring incision. In general, a pressure of 8 to 10 mm Hg is used to minimize the tenting of the diaphragm by the CO 2 . The upper abdomen and diaphragm are then evaluated, and the diagnosis of eventration is confirmed. If a diaphragmatic hernia is present, a laparoscopic repair can be performed, with or without resection of the sac. Generally, two additional ports (3 or 5 mm) are needed and are situated in the right and left epigastrium, slightly above the umbilical port ( Fig. 24-2 ). If the eventration is on the patient’s right, the left port should be slightly higher, and vice versa. Occasionally, if the eventration is on the right, a fourth port or stab incision is necessary in a subcostal position to place an instrument to depress the dome of the liver.