Diaphragm injury
Executive Summary
Diaphragmatic injuries present significant diagnostic challenges due to their often asymptomatic nature and subtle radiological presentation. Failure to recognize these injuries in the acute phase frequently leads to diaphragmatic herniation, particularly on the left side. Current surgical standards dictate that any asymptomatic penetrating injury to the left thoracoabdominal region—defined as the area between the nipple line superiorly and the costal margin inferiorly—must be evaluated, typically via laparoscopy, to rule out injury.
Surgical repair can be achieved through laparoscopic or open (laparotomy) approaches. Key technical requirements include the use of non-absorbable sutures, tension-free anastomosis, and, in cases of complex injuries or avulsions, securing the diaphragm to the chest wall. Critical postoperative care requires the placement of a thoracotomy tube to ensure drainage and manage potential pleural contamination.
Surgical Anatomy of the Diaphragm
The diaphragm is a complex muscular and aponeurotic structure that serves as the primary boundary between the thoracic and abdominal cavities.
Composition: It consists of a peripheral muscular segment and a central aponeurotic segment.
Attachments: The structure attaches to the lower sternum, the lower six ribs, and the lumbar spine.
Physiological Movement: During expiration, the diaphragm reaches the level of the nipples. Its central tendon is fused to the base of the pericardium.
Major Openings:
Aortic Foramen: Passage for the aorta, azygos vein, and thoracic duct.
Esophageal Foramen: Passage for the esophagus and vagus nerves.
Vena Cava Foramen: Contains the inferior vena cava.
Vascular and Nerve Supply:
Arterial: Phrenic arteries branching directly from the aorta at the hiatus.
Venous: Drainage directly into the inferior vena cava.
Innervation: The phrenic nerve, originating from the C3–C5 nerve roots. It courses over the anterior scalene muscle, through the mediastinum along the pericardium, and terminates in the diaphragm.
General Principles of Diagnosis and Evaluation
Diagnosis is often delayed because isolated, uncomplicated injuries may not present with clear symptoms.
Risk of Herniation: Untreated injuries inevitably result in diaphragmatic hernia. While the left side is more commonly affected, both sides are at risk.
Screening Requirements: Any asymptomatic penetrating injury to the left thoracoabdominal area (between the nipple superiorly and the costal margin inferiorly) requires laparoscopic evaluation to rule out injury.
Surgical Access: Isolated injuries can be managed through laparoscopy or laparotomy.
Laparoscopic Repair Protocols
Laparoscopy is a primary tool for both the diagnosis and repair of diaphragmatic injuries.
Positioning and Access
Patient Position: Initially supine. After trocar insertion, the patient should be moved into reverse Trendelenburg and right decubitus to improve visualization of the left diaphragm.
Incisions: Trocar placement follows triangulation principles. A standard supra-umbilical trocar is used for the camera. Once an injury is localized, additional ports are added to maximize access.
Repair Technique
Sutures: Lacerations are repaired with interrupted non-absorbable sutures.
Alternatives: Laparoscopic hernia staples may be utilized.
Visualization: It is critical to grasp the diaphragm and pull it toward the camera to ensure a "good suture bite" during figure-of-eight suturing.
Open Repair Protocols
Open repair (laparotomy) is indicated for complex injuries or when a complete investigation of the abdomen is necessary.
Positioning and Exposure
Position: Supine with both arms abducted.
Incision: A standard midline laparotomy. A thoracic approach may be considered for chronic injuries.
Retraction: Superior cephalad retraction of the costal margins is essential. Use of a fixed retractor (e.g., Bookwalter retractor) is strongly recommended.
Edge Management: Allis clamps are used to grasp wound edges and pull them anteriorly to facilitate suturing, especially for posterior injuries which are difficult to access.
Hernia Management
If a hernia is present, contents must be reduced using gentle traction. If the defect is too small for reduction, it should be enlarged. All incarcerated contents must be inspected for ischemic necrosis.
Technical Repair Specifications
The method of repair depends on the nature and size of the injury:
Tissue Reinforcement
Tissue flaps may be used to reinforce esophageal repairs associated with diaphragmatic injury, particularly to prevent tracheoesophageal or arterioesophageal fistulas. Options include:
Pleural flaps.
Intercostal muscle flaps.
Pericardial fat-pad flaps.
Critical Tips and Clinical Pitfalls
Procedural Risks
Tension Pneumothorax: Abdominal insufflation during laparoscopy carries a risk of tension pneumothorax if a diaphragmatic defect exists. Surgeons must monitor hemodynamics and oxygenation closely. If signs develop, insufflation must be released and a chest drain inserted.
Loss of Pressure: Laparoscopic repair can be difficult if pressure is lost through the defect. Grasping the edges with forceps and partially twisting them can occlude the defect to allow repair.
Myocardial Injury: When repairing injuries near the pericardium, sutures must be placed under direct visualization to avoid injuring the myocardium.
Infection and Drainage
Pleural Contamination: If peritoneal content contamination is present, there is a high risk of empyema. The pleural cavity must be washed out through the diaphragmatic defect.
Drainage: Routine wide drainage of esophageal repairs is critical. For all diaphragmatic repairs, a thoracotomy tube must be placed for postoperative drainage.
Esophageal Considerations
Delayed recognition of associated esophageal injuries is linked to high rates of infection and death. While cervical esophageal leaks are rarely life-threatening, thoracic esophageal leaks can cause severe mediastinitis and are often fatal. All esophageal repairs must be tension-free and well-perfused.
