Survival of multiple nail gun injuries to the head, lung, and heart: A case report


 Background:

Most nail gun injuries occur at the extremities due to working accidents. Injuries to the brain or thorax are relatively rare, and cases with both injuries are even rarer. Initial evaluation, resuscitation and surgical planning can be challenging.
Case presentation:

Here, we present a case with nail gun injuries to the brain, lung, and heart by suicide attempt. The patient presented to the emergency department under shock. After resuscitation and surgical intervention, he was discharged without significant morbidity.
Conclusions:

Multiple nail gun injuries, especially those to vital organs such as the brain, lung, and heart, can be challenging to emergency physicians and surgeons. Imaging tools, treatment strategies, and possible complications are discussed in this article to provide optimized outcomes in such situations.

right temporal area (Fig. 1A), and three on the left chest (Fig. 1B), about 2 cm above the left nipple.
Trauma code was initiated immediately to provide immediate treatment and resuscitation. Whole body computed tomography (CT) revealed three metallic nails penetrating the left lower anterior chest wall through the lung to the heart with signi cant hemopericardium and moderate haemothorax ( Fig. 2A).
Brain CT showed one metallic nail punctured through the right temporal bone without intracranial haemorrhage (ICH) (Fig. 2B). After consultation with the cardiac surgeon, chest surgeon, and neurosurgeon, an emergency operation was arranged.
Through median sternotomy, the cardiac surgeon opened the pericardium to identify two rupture sites on the left ventricle (LV) adjacent to the left anterior descending (LAD) artery bifurcation (Fig. 3B). Each rupture wound was repaired using pledgeted 4 − 0 prolene sutures (Fig. 3C). Using a sternotomy wound approach, during the removal of three ve-centimetre-long steel nails, a through-and-through penetration of the left upper lobe of the lung was also noted. Wedge resection was done by the chest surgeon.
Massive normal saline irrigation was performed after the heart and lung repair. After surgery, the patient was admitted to the surgical intensive care unit for further resuscitation.
Eight hours later, the patient's haemodynamic status was stable without use of a vasopressor or antiarrhythmic agents. We then performed a craniotomy around the nail on the right temporal bone (Fig. 4A).
The nail puncture hole in the brain was contiguous with two branches of the super cial cerebral vein ( Fig. 4B). No vessel was injured by the nail. There was mild oozing from the brain after removal of the nail without signi cant hematoma. After the operation, the patient was extubated on postoperative day (POD) one and transferred to the general ward on POD three with full consciousness. In the general ward, the patient's vital signs and consciousness remained stable, there was no limb weakness, dysphagia, dysarthria, or arrhythmia. We consulted the psychiatric department for drug abuse evaluation, as well as social workers for discharge planning. Fourteen days after transferring to the ward, the patient was discharged to home.

Discussion And Conclusions
Nail gun injury An increasing number of medical reports have described traumatic injuries resulting from nail guns(2, 3), of which most appear to have been related to unintentional nail gun discharge or mis re (4). Though the majority of nail gun-associated injuries are puncture wounds to the extremities, there are increasing numbers of reports of chest or torso injuries, especially self-in icted cases (5,6). Using a nail gun to attempt suicide usually is fatal (7).
The projectile speed of a nail gun ranges from 150 ft/s (45.7 m/s) (pneumatic nail gun) to 1400 ft/s (426.7 m/s) (powder-actuated tool)(1). The former delivers less energy and does not cause signi cant lateral damage(4); while the latter was reported to be able to create temporary cavities similar to those caused by rearms. They are a large number of pneumatic nail guns than powder-actuated ones, most likely because they are more widely used. Overall, among all penetrating injuries including rearms, nail gun injuries have better outcomes(1). However, there have been several reports of penetrating nail gun injuries leading to death (6,8,9).

Penetrating intracardiac injury
When it comes to thoracic penetrating injuries, the mortality rates vary widely depending on the penetrating object. Nail gun penetrating injuries to the heart have a mortality rate of up to 25%, while stabbing injuries of the heart range from 22-62%, and gunshot injuries have a much higher mortality rate from 60-95% (1,6,(10)(11)(12). In this type of potential life-threatening injury, rapid diagnosis is required to guide management. In our case, though shock status was noted initially, the vital signs rapidly responded after resuscitation with crystalloid and blood transfusion. CT of the head and chest was performed promptly after resuscitation. We found hemopericardium and left haemothorax, and at least 2 metallic nail tips in the pericardial space ( Fig. 2A). Despite bedside sonography being suggested as the rst-line evaluation for suspected cardiac penetrating injuries (5), the easy accessibility of CT makes it an essential part of the initial patient assessment (13). Furthermore, CT is the best method to evaluate penetrating head injuries. Also, CT can provide the information to survey the penetrating tract, plan surgical procedures, and even predict the outcome for the patient (8). In patients with atherosclerosis, which our patient did not have, coronary artery injuries can sometimes be identi ed by CT scans due to the calci cation patches, which may contribute to the prediction of surgical ndings (8).
When the penetration injury involves the heart, both sternotomy and thoracotomy can be performed (5), and the choice is based on the discretion of the surgeon (8). Right ventricle (RV) injuries are most reported in penetrating cardiac injuries(6). Panicker et al. reported a pledgeted purse string method for simultaneous closure of the RV wound while removing the nail(5). Our patient's heart injuries, however, were on the LV, which cannot be directly seen even during median sternotomy. LV injuries are also harder to repair due to the higher intraventricular pressure and more severe haemopericardium (8). We had to perform a rotation of the heart, removal of the nail, before we could repair the penetration wound with pledgeted sutures. Besides, we did not perform cardiopulmonary bypass during the operation due to the patient having a penetrating brain injury. After surgery, the heartrate should be closely

Penetrating lung injuries
In general, penetrating lung injuries with pneumothorax or haemothorax can be initially treated with tube thoracostomy. If there is persistent air leak,massive haemothorax, or retained haemothorax, then surgery should be considered. In our case, after cardiac muscle repair, we extended the wound of the sternotomy into the left pleural space, and the left upper lobe revealed one small laceration without active bleeding. Wedge resection was then performed. After the procedure, there was no air leak noted by a water immersion test.

Penetrating brain injuries
Probably due to the low velocity and lack of lateral damage mentioned above, most patients with intracranial nail gun injuries present to the ED with clear consciousness, and the mortality and morbidity rates are low (14,15).
Unlike thorax, image surveys in penetrating injuries to the head rely on CT scans to identify the location of the nail, ICH, and fragments (13,(16)(17)(18). However, signi cant artefacts are frequently present, as in this case (Fig. 2B). If the nail is close to major vessels, cerebral angiography is recommended to rule out vascular injury (13).Additionally, it can serve as a baseline for later post-traumatic pseudoaneurysms or stulas, as stated in multiple reports (19)(20)(21)(22).
Both craniotomy and blind retrieval can remove the intracranial nail. Although blind retrieval can remove nails with heads outside of the skull (13,23,24), complications including delayed ICH have been reported in several studies (13,(23)(24)(25)(26)(27). Therefore, craniotomy is strongly suggested for embedded nails to perform debridement and hematoma examination.
No matter which surgical method is adopted, close intracranial pressure monitoring is suggested after surgery (28). The most common postoperative complications for penetrating brain injuries are infection and epilepsy. The infection rates ranges from 55-90% within 3 and 6 weeks, respectively (29). Due to the high infection rate, prophylactic tetanus and broad-spectrum antibiotics should be initiated as early as possible (18,28,29). On the other hand, the percentage of epilepsy after penetrating brain injuries is around 30-50%, signi cantly higher than the 1.5-27% in blunt brain injuries (18). Prophylactic antiepileptics are recommended to prevent early post-traumatic epilepsy (28,30,31). However, their duration is still controversial for the prevention of late post-traumatic epilepsy. In this case, we prescribed valproic acid before craniotomy due to focal convulsions. After craniotomy, levetiracetam was also given due to recurrent focalconvulsions.

Timing of Intervention
Ideally, surgical intervention should be performed within 12 hours for penetrating brain injuries (18,32,33), that is, if there was no obvious mass effect or active bleeding that indicated emergency surgery(34). In this case, there is no doubt that emergency sternotomy was indicated due to suspected LV rupture, hemopericardium, and shock. Yet our patient did not have neurologic symptoms nor image evidence of ICH that may have progressed rapidly. Due to the above condition, we chose to perform the sternotomy rst, admitted the patient to the ICU for close monitoring, and arranged for craniotomy after the patient stabilized. Ye et al. reported a similar case with nail gun injuries to the LV and brain but with signi cant ICH. They performed emergency sternotomy to repair the rupture sites of the LV with off-pump to preserve cerebral perfusion just prior to emergency craniotomy(8).

Conclusion
Although nail gun injuries to vital organs are rare, the number of reported cases are increasing. We report a case with nail gun penetrating injuries to the heart, lung, and brain that survived without sequelae.
Emergency CT played an important role in diagnosis, surgical planning, and outcome prediction. Rapid evaluation, resuscitation, and appropriate treatment are important in such cases. We would like to share our experience, decision making, and surgical strategy.

Consent for Publication
The patient agreed to publication of this case report

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