Symptomatic hepatothorax presenting 25 years after penetrating thoracoabdominal injury

Abstract

Hepatic herniation through the diaphragm is a rare finding. It generally occurs due to a congenital diaphragmatic abnormality or blunt trauma resulting in a diaphragmatic defect. Making the diagnosis is difficult, as there are few definitive clinical signs and chest radiograph (CXR) findings may be non-specific. To our knowledge, only a single case report exists of penetrating right diaphragm injury leading to hepatic herniation.

A 42-year-old man presented to the emergency department of a regional hospital with hyperglycaemia and exertional dyspnoea. He was diagnosed with diabetes mellitus type 2. He gave a history of smoking for 15 pack-years, was negative for retroviral disease and had no history of pulmonary tuberculosis. He had no significant surgical history but reported being stabbed with a knife in 1995. The point of entry was below the level of the nipple in the right anterior axillary line. At the time, he was treated with an intercostal drain and discharged home.

CXR showed a right-sided chest mass. We considered a differential diagnosis of pulmonary consolidation, diaphragm eventration or hepatothorax. Computerized tomography of the chest and abdomen demonstrated apparent intrathoracic extension of the right liver lobe and partial attenuation of the superior vena cava and right atrium due to a mass effect. The upper border of the liver abutted the aortic arch. Surgical treatment options were discussed. The patient declined surgery and will be followed up as an outpatient.

Introduction

Hepatic herniation through the diaphragm is a rare finding.¹ It generally occurs due to a congenital diaphragmatic abnormality or blunt trauma resulting in a diaphragmatic defect.¹ Making the diagnosis is difficult, as there are few definitive clinical signs and chest radiograph (CXR) findings may be non-specific.² To our knowledge, only a single case report exists of penetrating right diaphragm injury leading to hepatic herniation.³

Case history

A 42-year-old man presented to the emergency department of a regional hospital with hyperglycaemia and exertional dyspnoea. He was diagnosed with diabetes mellitus type 2. He gave a history of smoking for 15 pack-years, was negative for retroviral disease and had no history of pulmonary tuberculosis. He had no significant surgical history, but he reported being stabbed with a knife in 1995. The point of entry was below the level of the nipple in the right anterior axillary line. At the time, he was treated with an intercostal drain and discharged home. He had had no respiratory symptoms until the presenting episode.

The patient was alert and awake, but tachycardic (103 beats/minute), tachypnoeic (18 breaths/minute) and normotensive. His oxygen saturation was 98% on room air. There was decreased air entry on the right chest compared with the left. Anteriorly on the right, there was no air entry, but posteriorly some breath sounds could be heard. There were no added sounds. The abdomen was soft and not tender, with normal bowel sounds. The liver was normal to percussion and not palpable below the costal margin.

CXR (Figures 1 and 2) showed a right-sided chest mass. We considered a differential diagnosis of pulmonary consolidation, diaphragm eventration or hepatothorax. Computed tomography (CT) of the chest and abdomen (Figures 3–5) demonstrated apparent intrathoracic extension of the right liver lobe and partial attenuation of the superior vena cava and right atrium due to a mass effect. The upper border of the liver abutted the aortic arch. We discussed surgical treatment options, but as the patient was asymptomatic after optimization of his hyperglycaemia, he declined surgery and will be followed up regularly as an outpatient.

Figure 1.

Erect chest x-ray

Figure 2.

Lateral chest x-ray

Figure 3.

Computed tomography axial view

Figure 5.

Computed tomography axial view

Figure 4.

Computed tomography axial view

Discussion

Traumatic diaphragmatic defects occur in approximately 0.4% of patients after blunt or penetrating thoracoabdominal trauma.⁴ The left side is more frequently affected (80%), most likely due to a combination of the protective effect of the liver on the right and inherent weakness of the left posterolateral hemidiaphragm.^3,4 Mechanisms such as vehicular crashes or falls from a height cause forceful blunt compression with a rise in intra-abdominal pressure, leading to a blow-out rupture of the diaphragm. Penetrating diaphragmatic injuries most commonly occur due to stabs, gunshots or impalements.^3,4

The pathophysiology of evolving diaphragmatic injuries can be divided into the acute, latent and obstructive phases. During the acute phase, the patient is typically symptomatic due to the primary injury. In the latent phase, gradual and relatively asymptomatic herniation may occur over an extended period of time. Several years after the initial injury, in the obstructive phase, the patient may present with symptoms of visceral ischaemia or intestinal obstruction.^3,4

Right-sided diaphragmatic injury is unusual. It is more likely to occur after blunt trauma, and subsequent visceral herniation is reported to occur in up to 20% of cases.³ Hepatic herniation is a rare complication of right-sided diaphragmatic rupture; we identified only one case, where, secondary to a bull attack, impalement of the right chest and blunt thoracoabdominal trauma led to a diaphragmatic rupture and hepatothorax.³ To our knowledge, no case of a pure penetrating injury of the right diaphragm leading to hepatic herniation has been described.

In blunt trauma, the extent of hepatic herniation is related directly to the size of the diaphragmatic defect.⁵ Unrepaired diaphragmatic injuries increase in size over time, increasing the risk of visceral herniation.⁴ Patients may present with abdominal or chest pain, respiratory distress, cardiac arrhythmias and hypotension. As the herniation progresses, pulmonary collapse, mediastinal compression and subsequent acute haemodynamic instability may develop.⁵

CXR is the first-line radiological investigation for patients with suspected diaphragm rupture. It has an overall sensitivity and specificity of 25–70%.⁴ In the absence of viscerothorax, non-specific signs of diaphragmatic rupture include an elevated hemidiaphragm, an irregular outline, compression atelectasis and mediastinal shift. CT scan is the investigation of choice, with a specificity of nearly 83% and a sensitivity of 50% for right-sided rupture.⁴ Magnetic resonance imaging is of limited use in the acute setting but may play a role in latent traumatic diaphragmatic hernias.⁵

Surgical repair of hepatic herniation may be via thoracotomy, laparotomy or a combined approach. The technique should be individualized, depending on the surgeon’s preference.⁴ For right-sided diaphragmatic rupture, thoracotomy is generally recommended due to the technical challenges associated with transabdominal right hemidiaphragm repair.⁴ This approach also allows for separation of adhesions between the associated viscera, lung and chest wall. If required, decortication may also be performed.^4,5 The diaphragmatic defect may be enlarged to allow reduction of the viscera. Once the visceral hernia is reduced, defects of up to 6cm may be repaired with interrupted sutures using non-absorbable or absorbable suture material. Interrupted figure-of-eight or horizontal mattress sutures are recommended for larger defects.⁴ For large defects, a mesh repair may be required to minimize tension on the wound.^4,5