Missed diaphragmatic injuries can result in major morbidity and/or mortality. Penetrating thoracoabdominal injuries carry a high risk of diaphragmatic injuries but can also pose a diagnostic dilemma due to their small size and the frequent lack of an associated hernia. Penetrating injury to the abdomen or chest from the 4^th through the 12^th thoracic dermatomes anteriorly and the 3^rd lumber region posteriorly. Probability of diaphragmatic injury was higher among patients with penetrating injury to the 8th intercostal space. Thus, surgeons should consider the bullet to have potentially caused a diaphragmatic injury. This role makes it easy to predict diaphragmatic injury in suspected cases [1] .

Diaphragmatic injuries can result in significant ventilatory compromise. Diagnosis may not be obvious [2] . It is made preoperatively in only 40% - 50% of left-sided and 0% - 10% of right-sided blunt diaphragmatic ruptures [3] . In 10% - 50% of patients, diagnosis is not made in the first 24 hours. In only approximately 3% of cases, the injury is bilateral [4] . Early deaths usually result from associated injuries rather than the diaphragmatic tears. Mortality ranges from 5% to 30% [5] .

If one gets shot in the diaphragm, and if the diaphragm is injured, it is an indication that more severe injuries to organs may have occurred. Thus, the mortality after a diagnosis of diaphragmatic rupture is 17%, with most deaths due to associated lesions. In our presented case, the diaphragm suffered two lacerations with minimal lung basal lesion [6] .

Chest X-ray remains an important tool in early diagnosis but primarily relies on the presence of a hernia or a discontinuity of the diaphragm, which is not typically seen with penetrating injuries. Computed tomography has a higher sensitivity and specificity and improves preoperative diagnosis. Organ herniation was observed significantly more often in blunt trauma than in penetrating trauma [7] .

The surgical procedure involved a reduction of herniated viscera and a suture of the diaphragm by non-absorbable suture materials in 85% [8] .

Thoracoscopy and/or laparoscopy provide the most definitive morphological assessment of the diaphragm [9] . One prospective study, in which patients suffering penetrating trauma to the left lower chest underwent routine laparoscopy, found that 24% had sustained occult diaphragmatic injuries [10] . These techniques can also identify other injuries to viscera which might otherwise not be apparent in radiological imaging [11] .

Definitive treatment of diaphragmatic injury requires surgical repair, the approach (trans-abdominal or trans-thoracic) being determined by co-existing injuries. The trans-abdominal approach is otherwise preferred in the acute setting [12] . In patients undergoing laparotomy for other injuries, the hemidiaphragms should be visualized to identify any tears [13] .

According to McDonald, et al., 2018, guidelines: In left-sided thoracoabdominal stab wound patients who are hemodynamically stable and without peritonitis, should laparoscopy be performed to decrease the incidence of missed diaphragmatic injury [13] .

We present a case of a male adult patient, 23 years old. He came from Aswan to Ismailia 2 weeks after a bullet injury to his left side of chest The inlet of the bullet was through the left nipple, and the exit was just below the angle of his left scapula. We expected severe pulmonary and/or gastric injuries. Diagnosis of diaphragmatic tears without the presence of herniated viscera remains difficult and a high index of suspicion must be maintained. Chest CT showed two interruptions in the left diaphragmatic copula with omental herniations through both. This was confirmed with chest CT and barium swallow contrast ( Figure 1 , Figure 2 ). Physical examination showed mild upper abdominal tenderness. The abdominal ultrasound examination did not show any evidence of intra-abdominal visceral injury. CT of chest with oral contrast showed the lateral hole with herniated omental fat. This smaller antero-lateral diaphragmatic tear is nearer to the exit of the bullet ( Figure 1 ), the medial larger tear with herniated omental fat lies postero-medial and is radially directed diaphragmatic tear ( Figure 2 ).

Once diagnosed, the only treatment for a diaphragmatic tear was a decision of surgery. As our patient was hemodynamically stable and according to the guidelines, we got an informed consent to proceed with thoracoscopy. It was done using a thin tube with a tiny video camera at the end (thoracoscope). It’s a type of minimally invasive surgery. We made three cuts, each one was smaller than half an inch over the seventh, sixth and fourth ribs., put a thoracoscope into the pleural space and put other tools into the other incisions.

Thoracoscopic exploration, single lung ventilation and CO₂ insufflation were performed. The latter facilitated reduction of herniated omental fat and closure of the smaller defect followed by reduction and closure of the larger medial one. There were adhesions between omental fat and edges of the holes as well as the base of the lung ( Figure 3 , Figure 4 ). Adhesions were released with blunt dissection. We found a small posterior basal lung burn with a small blood clot covering that area. The defects were repaired in two layers with non-absorbable suture materials. Inserted chest tube and closed chest wall in layers. One day after thoracoscopy, plain x-ray of chest showed gas under the diaphragm ( Figure 5 ). During thoracoscopy, we insufflated CO₂ gas that facilitated reduction of the herniated omentum, some gas escaped under the diaphragm.

Young age and good preparation enhanced early recovery, and the patient was discharged on the 4^th postoperative day. One month later, it did not show any complications.

Penetrating stab wounds are particularly dangerous as small defects in the diaphragm contribute to missed diagnosis and increased risk of gastric or intestinal strangulation. Signs to look for include absence or displacement of fundic gas, elevation of the hemidiaphragm, blunting of the diaphragmatic angle and hemopneumothorax.

Injuries to the diaphragm occur in 3% to 5% of patients who sustain penetrating chest trauma and are associated with an increased risk of major morbidity and mortality. Diaphragmatic injuries can be difficult to diagnose and, when missed, can result in a chronic diaphragmatic hernia, with the potential for incarceration, strangulation, and death. Video-assisted thoracoscopic surgery (VATS) has been shown to improve the sensitivity, specificity, and accuracy of identifying such lesions. The diagnosis in our case was missed at the primary care unit. CT-Chet proved the presence of not only one but also another larger radially directed tear.

This unique case presentation describes the first case of a penetrating bullet that only causes two diaphragmatic tears with omental herniation. Knowledge of the mechanisms that produce diaphragmatic rupture combined with information regarding the victim’s seat position and direction of the impacting force should lead to a high index of clinical suspicion for this lesion after blunt trauma. Due to the pressure differential between abdomen and thorax, the natural history of these injuries is one of enlargement and herniation. A sudden increase in the pressure gradient between the plural and peritoneal cavities that occur with high-speed blunt or penetrating trauma will lead to disruptions of the diaphragm and diaphragmatic tears [14] .

In this unique case presentation, we found a lateral small tear in line with the inlet and exit of the bullet and adjacent to the minor lung lesion, this diaphragmatic laceration can be explained by direct bullet injury. The second larger medial radially directed-diaphragmatic tear can be due to indirect trauma caused by the markedly increased intrathoracic pressure with closed epiglottis; this pressure was immediately created on penetration of skin and induced by intense pain or fear. His cousin was shotting him under his vision, face to face. This increasing intrathoracic pressure is going to be relieved by either bronchial or diaphragmatic rupture (a form of severe barotrauma). The diaphragm ruptured due to indirect trauma producing that large medial radially directed laceration followed by direct diaphragmatic injury in the path of the bullet. Diaphragmatic injury is a recognized consequence of high velocity blunt or penetrating trauma to the abdomen and/or chest [15] .

The traumatic diaphragmatic hernia was missed but shortly detected in our Center. Diagnosis of diaphragmatic rupture following thoracic penetrating trauma is very challenging in asymptomatic patients with stable vital signs. Diaphragmatic injury is easily missed as it is uncommonly encountered and may not cause respiratory or gastrointestinal symptoms in the acute phase. Diaphragmatic injury has an associated mortality as high as 25% and failure to intervene can lead to delayed complications, e.g. bowel obstruction, perforation, and intra-thoracic sepsis [16] .

Assessment with sonography is significant.: Sensitivity 50%, specificity 100%, positive and negative predictive values: 9.1% (95% CI: 1.5 - 30.6), Infinity, and 0.1 (95% CI: 0.02 - 0.37), respectively. The overall accuracy of assessment with sonography in this regard was 75.0% (95% CI: 42.3 - 100.0). It was not conclusive in our case. It cannot be the definitive alternative to diagnostic laparoscopy or thoracoscopy to detect diaphragm rupture.

CT-chest is more accurate in diagnosis of diaphragmatic injuries. Various studies have revealed CT-chest to have a variable sensitivity and specificity of 61% - 87% and 72% - 100%, respectively, for the diagnosis of diaphragmatic rupture. The dangling diaphragm sign denotes that a part of the diaphragm appears folded, thickened, and hanging.

The most definitive diagnostic approach can be thoracoscopy or laparoscopy as proved by several studies. There are reported different approaches for surgical treatment: abdominal or thoracic, traditional incision or minimally invasive approaches. Repair was done using absorbable or nonabsorbable suture material, interrupted or continuous and in one or two layers. The most important fact is that any tear should be closed whatever its size.

Postoperative Follow up for 4 weeks is significant to exclude development of any complications. Clinical and radiological examinations are indicated during follow up. Other authors reported the morbidity rate was 10 % and mortality rate 5%. The presented case had no morbidity, and the patient is having a good eventless life.

The importance of early diagnosis of diaphragmatic tears in reducing mortality, morbidity and hospital stay is significant. A high index of suspicion, careful clinical examination, and serial chest radiographs remain the best way of making the diagnosis. Thoracoscopy is a good approach for diagnosis and treatment.

A penetrating bullet can produce diaphragmatic lacerations both directly and indirectly.

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available and can be submitted to any reasonable request.

Ahmed Hamdy initiated the report which was drafted by Hamdy D. Elayouty. All authors made important critical revisions. All authors approved the final manuscript.