The two principles of repairing acute diaphragmatic hernias are complete reduction of the herniated organs back into the abdominal cavity and watertight closure of the defect to prevent recurrence. Given the high rate of associated abdominal injuries (generally 1.6 intra-abdominal injuries per patient on average), repair of the acutely injured diaphragm is best performed via an exploratory laparotomy.28,38,39 The right hemidiaphragm is best inspected after transection of the falciform ligament and downward traction of the liver. The left hemidiaphragm can be inspected by applying gentle downward retraction of the spleen and greater curvature of the stomach. The central tendon of the diaphragm should also be examined, along with the esophageal hiatus. Reduction of the intra-abdominal contents is generally not difficult in the period immediately following injury. If the herniated contents are difficult to reduce, the phrenotomy can be partially extended to facilitate reduction, with care taken to avoid injury to the phrenic nerve.
It may be necessary to carefully debride the edges of a laceration if devitalized tissue is found, as with a high-velocity missile or close-range shotgun wound. The edges of the diaphragmatic laceration should then be grasped with Allis clamps, and the laceration spread apart to inspect the ipsilateral pleural cavity. This allows for evaluation of ongoing hemorrhage from within the thoracic cavity, as well as the determination of the degree of contamination between the abdominal and thoracic cavities. Small diaphragmatic disruptions, commonly seen after penetrating trauma, can generally be repaired using interrupted nonabsorbable sutures. Larger defects, more likely associated with blunt trauma, may be repaired in a number of different ways, including interrupted figure of eight or horizontal mattress sutures, a running hemostatic suture line, or a double layer repair, using a combination of the two methods (Fig. 28-8). Generally, a no. 0- or 1-monofilament or braided nonabsorbable suture is used. The authors prefer a no. 1-nonabsorbable monofilament placed in an interrupted fashion for the repair of traumatic diaphragmatic defects. In patients in whom a laceration through the central tendon exposes the inferior aspect of the heart, meticulous attention is given to the placement of the sutures to prevent inadvertent puncture or laceration of the myocardium. At the completion of the repair, the integrity of the suture line may be tested by increasing intrathoracic pressure with the administration of large tidal volumes and assessment of diaphragmatic motion. This maneuver is repeated with the field flooded with sterile saline to determine if there is escape of air through the suture line.
Technique for two-layer repair of diaphragmatic defect. (Reproduced with permission from Juan A. Asensio, MD, FACS, FCCM and Demetrios Demetriades, MD, PhD, FACS.)
In cases where there is concomitant injury to a hollow viscus in the abdomen, contamination of the chest will have occurred due to the pressure gradient between the positive pressure in the abdomen and the negative pressure in the thoracic cavity. In this event, careful irrigation of the thoracic cavity through the diaphragmatic disruption is necessary prior to diaphragmatic repair, as empyema is three times more prevalent when there is an associated injury to the bowel.28,40 Zellweger et al41 studied the management of patients with penetrating thoracoabdominal wounds that injured the diaphragm and gastrointestinal tract and/or liver. He demonstrated that a transdiaphragmatic washout of the pleural cavity was an effective strategy to decrease thoracic contamination.41
Laparoscopic repair of diaphragmatic injuries is feasible. A diaphragmatic injury diagnosed by laparoscopy in the absence of other injuries mandating laparotomy or thoracotomy can be repaired with this approach.36 Laparoscopic repairs of diaphragmatic injuries can be performed with sutures or staples.14,15 The decision to proceed laparoscopically should be solely dependent on the skill of the operating surgeon. For laparoscopic explorations to rule out a left-sided diaphragmatic injury where diaphragmatic repair is contemplated, also, port placement is important. The initial port should be at the level of the umbilicus or just above depending on the patient’s body habitus. A sub-xiphoid port is placed for retraction of the liver, and a port is placed laterally on the left side just below the costal margin. This port is utilized to maintain traction on the stomach or other cranially herniated abdominal organs. The umbilical port is utilized for the 30° laparoscopic camera. Two additional ports in the bilateral mid-clavicular lines are used as working ports. These two ports are also placed in a subcostal location. After placing the patient in steep reverse Trendelenburg position and careful reduction of the abdominal contents back into the abdomen, the defect is repaired. Techniques of repair are identical to the open methods. For right-sided injuries, port placement is similar, moving the left lateral subcostal port to the right. The right lobe of the liver is retracted medially or caudally. The falciform ligament and the right triangular ligament may require division for adequate retraction and exposure of the injury.
At times, a thoracotomy is required for the management of a massive hemothorax, defined as greater that 1500 cc of blood on insertion of a chest tube or in the first 15–30 minutes or more than 200 cc of blood per hour for the first 4 hours after trauma.42 A laceration of the right hemidiaphragm with an associated laceration of the liver may present as a massive hemothorax, with the diagnosis made at the time of thoracotomy. In this scenario, the diaphragm may be repaired through the chest, but a formal laparotomy will be necessary for the operative management of the hepatic injury and to rule out other associated intra-abdominal injuries.
For thoracoscopic management of a known diaphragmatic injury, the patient is placed in the lateral decubitus position with the arm abducted to allow maximal superior displacement of the scapula. The initial 2 cm incision should be placed just below the tip of the scapula. Two further incisions are then placed to complete a triangle based on the patient’s intrathoracic anatomy. The principles of visceral reduction and the technique of repair remain similar to those used in open surgery.
Disruption of the diaphragm following high energy crushing injuries or major deceleration can result in avulsion of the diaphragm from its attachments to the chest wall. Repair of this injury may require an ipsilateral thoracotomy, which allows horizontal mattress sutures to be placed around the ribs and secures the diaphragm into its normal anatomic position. In the presence of a flail segment of the ipsilateral chest wall, formal fixation of the ribs may be required to facilitate this complex repair of the diaphragm.23 Prosthetic material for diaphragmatic reconstruction in the acute setting is rarely indicated, as tissue retraction and loss has not occurred and concomitant gastrointestinal injuries may lead to an increased rate of postoperative infection.
Massive diaphragmatic destruction such as that caused by thoracoabdominal shotgun injuries merits special mention. Bender and Lucas43 described the immediate reconstruction of the chest wall following this type of injury by first detaching the affected hemidiaphragm anteriorly, laterally, and posteriorly. The diaphragm was then translocated to a position above the full-thickness chest wall defect, which converted the defect functionally into an abdominal wall defect. This is performed by suturing the ribs at a higher intercostal space, while the abdominal wall defect was managed with local wound care in anticipation of reconstruction with either split-thickness skin grafts or myocutaneous flaps at a later date.43