Diaphragmatic Hernia

Most ADH cases follow episodes of trauma, either blunt or penetrating to the thorax or abdomen. A clear history of trauma should prompt appropriate imaging to determine the extent of the injury, which may then demonstrate the presence of ADH. For other causes of ADH, it is crucial to consider the patient's previous surgical history as this may provide a cause of the ADH. Patients can present with ADH in a variety of ways. AHD may produce respiratory, abdominal and in some cases cardiac symptoms.[20] The effect from the abdominal contents putting pressure on the thorax can result in shortness of breath and chest pain. Abdominal symptoms may also be present, including recurrent abdominal pain, postprandial fullness, vomiting, and obstructive gastrointestinal symptoms.[18] In some spontaneous cases, the DH may remain asymptomatic, only revealed upon imaging studies. Examination of the patient may reveal the absence of breath sounds over the lower chest area, with bowel sounds being audible.[21]

Imaging is vital for diagnosis of acquired diaphragmatic hernia. A variety of different imaging modalities are used to diagnose or aid diagnosis of a diaphragmatic hernia including chest radiographs, ultrasonography, and magnetic resonance imaging, with computed tomography (CT) being the modality of choice.[21]

Treatment of acquired diaphragmatic hernia in the acute setting requires appropriate resuscitation of the patient.[2] Management following this is surgical. Typically, the procedure will use an open abdominal approach, and the repair accomplished by primary closure.[14] In cases where primary closure with non-absorbable sutures is not possible because of the size of the defect then mesh repair may be an alternative.[18] If the diagnosis is delayed, then a thoracic approach is generally preferred to reduce viscera-pleural adhesions and intra-thoracic visceral perforation.[18] It may be appropriate in some delayed cases to use a combined thoracic-abdominal approach. A laparoscopic approach may be feasible and could be an option for repair-dependent upon experience.[14]

There is a broad range of differential diagnosis for ADH considering the variation in presentation and the variety of symptoms associated with it. Before imaging, a diaphragmatic hernia is unlikely to be high up the differential list for causation of the patient symptoms, except perhaps in cases associated with trauma. After imaging, an alternative diagnosis that should merit consideration is metastasis, particularly with small defects.[20] Congenital causes of a diaphragmatic hernia should always be a consideration particularly when trauma has not occurred previous to the presentation.[22]

If the clinician misses the diagnosis of acquired diaphragmatic hernia then there is a substantial risk of death; this can be due to lung compression with respiratory failure, vascular compromise with gastric or intestinal infarction, or perforation.[23] There is a documented variable risk in surgical mortality for diaphragmatic repair depending on concomitant injuries between 5 to 50%.[2] Generally, the outcomes following correction are good, with recurrence levels being low.[2]

Many potential complications can result from an acquired diaphragmatic hernia. Complications reported include diaphragmatic rupture, acute obstructive symptoms, respiratory failure incarceration, strangulation, and cardiac tamponade.[23][24]

Most cases of acquired diaphragmatic hernia occur in emergencies following trauma; in these situations, surgery is life-saving. If possible, consent for surgery should be obtained with an explanation of the potential complications from surgery. These should be balanced with the complications including death if the surgery is not carried out.

Acquired diaphragmatic hernia is a serious condition which requires urgent surgery in the majority of cases. Imaging is vital for diagnosis however may be difficult to interpret particularly with additional damage from trauma, discussion between radiologist and surgeons is essential to enhance decisions in treatment. There is no consistent and recommended approach to surgery, with a variety of different methods and options being available. Typically, the repair will be carried out by general surgeons. However, if there is a delay in diagnosis, a thoracic approach may be required, and communication with the cardiothoracic surgeons can be crucial. Acquired diaphragmatic hernia is rare, so information regarding treatment meaning case studies may be vital in aiding with complicated cases in determining surgical approach (level 5).