The two most common causes of diaphragmatic elevation are congenital eventration of the diaphragm and phrenic nerve palsy9,10 (see Chap. 129). Phrenic nerve paralysis can occur as a consequence of a viral palsy, iatrogenic injury during thoracic surgery, or fracture of an anterior first rib or clavicle.
Plication for Phrenic Nerve Palsy
The easiest technique of plication is to place imbricating stitches within the central tendon of the diaphragm.11,12 These stitches can be readily placed both thoracoscopically and through a minithoracotomy.13 If the sutures extend far enough from the edge of the diaphragmatic tendon, they can produce substantial caudal displacement of the tendon toward the abdominal cavity, permitting expansion of the ipsilateral lower lobe as well as balancing the mediastinum14 (Fig. 128-14). The drawback of this technique, however, is that while the majority of the pleats will fold the noncompliant central tendon, the compliant muscular remnant can be expected to stretch with time. It has been our experience that the central tendon pleating technique is associated with reelevation of the diaphragm to the level of the hilum within several years. Long-term follow-up of this technique has included reports of recurrent diaphragmatic elevation requiring additional intervention in as many as 19% of treated patients.15 Furthermore, the phrenic vessels and branches of the nerve travel near the insertion of the muscle into the edge of the tendon and cannot be visualized from the thoracic surface of the diaphragm. Yet, to displace the central tendon adequately, these stitches need to extend into the muscle area, which places the branches of the nerve at risk of injury.
Central tendon plication technique.
The top (thoracic) view of the diaphragm seen in Fig. 128-10 illustrates the radial spokes of the muscle fibers from their origin along the costal margin toward the central tendon. The phrenic nerve can be seen along the mediastinal pleura, but then it pierces the diaphragmatic muscle close to the inferior vena cava on the right and the tip of the acute angle of the heart on the left. The phrenic vessels and phrenic nerve cannot be visualized from the thoracic surface of the diaphragm beyond these areas.
Dr. David State described a subcostal radial plication technique for congenital eventration of the diaphragm in 1949.16 The original description of this technique included a generous incision across the right upper quadrant of the abdomen and placement of radial sutures along the muscular portion of the diaphragm to pull it toward the lateral chest wall. A transthoracic radial plication also has been described.14,17
Dr. John Foker at the University of Minnesota has used a transthoracic radial plication technique since 1976 to treat 35 children with elevation of the diaphragm.18 The repairs were performed with interrupted horizontal mattress pledgeted sutures imbricating the muscular portion of the diaphragm in a radial manner toward the chest wall via a posterolateral thoracotomy (Fig. 128-15). The plication sutures extend in an unbroken band from the xiphoid area to the vertebral body. No sutures are placed along the mediastinal pleura. The goal is to produce a taut diaphragm that appears as a straight, angled line from mediastinum to chest wall on an anteroposterior roentgenogram of the chest. I believe that this produces a plication that best mimics the contraction of the fan-shaped muscle while minimizing injury to the branches of the nerve or vessels.
Radial plication technique.
In this series, 31 of the 36 operations (86%) led to extubation within 3 days, even though 15 patients had been ventilator-dependent before plication.18 There were no deaths within 30 days and no morbidity directly attributed to the plication. Only one patient (3%) suffered a recurrence requiring repeat plication. Twenty-six of these patients survived long term (median 12 years at time of analysis), and eighteen of these patients were reevaluated with diaphragmatic ultrasound in 1996. Some degree of function had returned to 14 (78%) of the diaphragms.
I have extended this technique to a thoracoscopic approach in adults with elevated hemidiaphragms with some success. Currently, I use a three-port technique with an anterior and posterior port at the sixth and eighth intercostal spaces, respectively. The third port is subcostal and is used to pass an O-ring clamp through the abdominal cavity to grasp the undersurface of the central tendon of the diaphragm. This permits vigorous caudal displacement of the muscle to visualize the muscular imbrications for plication. The posterior thoracic port then is used to plicate the anterior and lateral borders of the muscle, while the anterior thoracic port is used to plicate the lateral and posterior borders.