Effectiveness of No-Zone Approach for Management of Isolated Penetrating Neck Injuries Among Hemodynamically Stable Patients. A Longitudinal Retrospective Study


 Background: Routine neck exploration for isolated penetrating neck injuries (PNIs) in hemodynamically stable patients increases the frequency of nontherapeutic surgeries, and complications. Current management protocol involves the no zone approach which uses physical examination and computerized tomographic angiography to guide treatment plans. This work aimed to study the effectiveness and reliability of no-zone approach for management of isolated PNIs in hemodynamically stable patients. Methods: cases of isolated PNIs in hemodynamically stable patients were managed using no zone approach. Detected injuries were managed accordingly. Results: This study included 106 patients. 34.9% of patients were managed conservatively while surgery was done at 65.09%. Vascular management was done in 40.57%, laryngotracheal repair in 29.2%, tracheostomy in 17%, pharyngeal repair in 7.55%, esophageal repair in 6.6%, and accessory nerve repair in 2.83%. Complications occurred in 16.04% of cases in the form of vascular complications (7.5%), respiratory complications (5.7%), pharyngoesophageal complications (1.9%), infections (12.3%), and neurological complications (7.5%). The survivors were 91.5% while deaths were 8.5%. Conclusion: The no-zone approach offers the ideal management for isolated PNIs in hemodynamically stable patients. It is advantageous over traditional approaches. Further studies are required to augment the evidence for its use as the gold standard management for such cases. Trial registration: the study was retrospectively registered at research registry with Research Registry UIN researchregistry5385 on February 26, 2020. Keywords: no zone approach, isolated penetrating neck injuries, hemodynamically stable patients, vascular injuries, laryngotracheal injury.

Thus, decision making and approach design are important for improving the outcome, decreasing morbidity and mortality (3).
Diagnosis is achieved by physical examination and supported by supplementary studies such as computed tomography and aerodigestive endoscopy. Currently, computed tomographic angiography (CTA) is the definitive tool for diagnosis, since it is quick, easily accessible, and accurate (4).
Surgeons used to classify the neck horizontally into three zones (I, II, and III) to facilitate the approach to PNIs (5,6). The classic management protocol for PNIs was the mandatory neck exploration to avoid missed injuries (7,8). It utilized the zone-based approach to guide investigations and management with very low rates of missed injuries and high rates of successful conservative management (9,10).
Its drawbacks included difficult classification of transcervical or multiple injuries, poor correlation between the external wound and the deep organ affection (11).
The Current management protocol involves the no zone approach which uses the physical examination and CTA to guide the treatment plan. It simplifies the management of PNIs and effectively identifies or excludes vascular and aerodigestive injuries. In addition, it resulted in insignificant missed lesions and insignificant negative explorations (1-2%) (11)(12)(13). CTA has high sensitivity and specificity approaching 90-100% and 93.5-100%, respectively for diagnosis of vascular injuries, thus replacing conventional angiography as the gold standard (14)(15)(16)(17).
Routine neck exploration in HSPs increases the frequency of unneeded surgeries, iatrogenic injuries, hospital stay, and complications (18)(19)(20). Hemodynamic stability does not exclude injury to underlying structures. Similarly, soft signs of vascular injury and suspicion of vascular injury did not indicate urgent intervention but should be thoroughly investigated and closely monitored (15).

The aim of the study:
This work aimed to study the effectiveness of the no-zone approach for the management of isolated PNIs among HSPs.

Study design, setting, and population
This study was a longitudinal retrospective study. It was conducted between July 2009 and July 2019 at Maxillofacial Surgery Unit, Surgery Department, Sohag University, Egypt. It included all cases of isolated PNIs in HSPs that presented and were managed.

Inclusion criteria
All HSPs with isolated PNI who accepted to engage in the study and signed informed consent.

Exclusion Criteria
Cases with isolated PNIs in hemodynamically unstable patients, injuries in other parts of the body or cervical spine and those who declined engagement in the study or unable to sign an informed consent. Investigations: in addition to the routine investiagations, CTA of the neck vessels was done for all cases.

Registeration
If an injury to the aerodigestive structure was suspected, fiberoptic flexible esophagoscopy and bronchoscopy under general anesthesia were done.

Management of airway and laryngotracheal injuries
Airway patency was the first priority. Tracheostomy was the preferred artificial airway, which was 1.
The complications and outcome: The complications were classified into vascular, respiratory, pharyngoesophageal, infections, the management.

Statistical Analysis:
Data was recorded in an excel spreadsheet, processed using the Statistical Package for the Social Sciences version 20. The Chi square frequency test was used to evaluate the effectiveness of the procedures was used.
Preoperative clinical data: Examination revealed the presence of findings suggestive of vascular injury in 51 cases (48.11%), and findings suggestive of airway injury in 45cases (42.45%), while other findings were less common.
The investigations revealed that the vascular injuries were the most common lesions (40.57%) followed by laryngotracheal 38 (35.85%) Other injuries were less common (Table 1).  (Table 2). Table 2 The details and management of vascular injuries:

Complications and outcome
Complications were detected in 17 cases (16.04%). Vascular complications were the commonest.
They were detected in 8 cases ( (Table 3). Table 3 The complications of management isolated penetrating neck injuries in hemodynamically stable patients The follow-up period ranged between six months to five years with a mean of 23 ± 4.2 months. The survivors were 97 (91.5%) while the number of deaths was 9 (8.5%) The Frequency distribution of the data was tested for the hypothesis for the efficiency of the surgical procedure using Chi square frequency.The tests showed significant results (p<0.05).

Discussion
PNIs are common and present in about 5-10% of trauma patients (21). Evaluation, diagnosis, and treatment of PNIs are challenging. Also, there is a major debate on decision making and approach in these injuries. The mandatory surgery has been substituted by a more selective and conservative approach (18,22).

Demographics and epidemiology:
In this study, there was a predominance of males (84.29%) than females (15.71%) with a maximum incidence in the third decade (48.57%) and the fourth decade (22.85%) and in the low socio-economic status group (77%). A low rate of incidence was reported in children below 10 years (2.6%) and a higher-class group (7.5%). Generally, PNIs are common in young males in the 3 rd and 4 th decades of and are uncommon in children (23)(24)(25). This is because the middle-aged males and low socioeconomic groups are more involved in daily activities and violence (26,27).
In the current study, PNIs were commonly caused by stab wounds (85.5%) which were in most cases secondary to road traffic accidents (59.4%) and to a less extent due to assaults (25.5%). On the contrary, Lydiatt et al (28) revealed that, in the United States, most PNIs were secondary to assaults while some cases are caused by accidents, such as falling on sharp objects and motor vehicle accidents. This difference can be explained by the presence of less violence in our country.
Preoperative data: In agreement with other studies (10,13,15,29), our cases had a high incidence of the manifestations of vascular injuries in 51 cases (48.11%) followed by the findings suggestive of airway injury in 45cases (42.45%). The pharyngo-esophageal and neurologic injuries were less common. The affection of aerodigestive structures is less because they locate deep in the neck and are more protected by the surrounding structures.
In our study, vascular injuries were the most common lesions detected by CTA in two-fifths of the cases (40.57%). Also, CTA was capable to detect injuries in other structures such as thyroid gland laryngotracheal, esophagus, and pharynx. With the assistance of other investigation, the laryngotracheal injuries were found in 35.85% of cases, thyroid gland injuries in 16.04%, pharyngeal and esophageal injuries in 7.55% and 6.6% of cases respectively. Accessory nerve injury was noticed in 2.83%. Other studies reported that arterial injury occurred in approximately 25% of PNIs (30).
In agreement with our strategy in the management of HSPs, Biffl WL et al. (9) used CTA to evaluate patients who didn't need immediate surgery. This radiological option has high sensitivity and specificity in the detection of vascular, laryngotracheal and many pharyngo-esophageal injuries, thereby it eliminates the role of other imaging investigations in the assessment of different types of injuries. In addition, it can offer data on the pathway of the injury and delineate the need for imaging of the chest. CTA has led to a marked reduction in classic neck explorations. (12,15,24,25,29) CTA has the probability of missing pharyngo-esophageal injuries, with some studies reported its sensitivity to be nearly 53%. (9,32) In accordance with other studies, we used the contrast swallow and fiberoptic flexible esophagoscopy to evaluate the pharyngoesophageal and laryngotracheal injuries. The pharyngeal injury was detected in 8 cases (7.55%) and esophageal injury in 7 cases (6.6%). Bronchoscopy detected laryngotracheal injury in 38 cases (35.85%). Lourencao J et al. (24) appreciated that additional imaging in stable patients with the potential pharyngo-esophageal injury.
Contrast swallow should be done and to be accompanied by a flexible esophagoscopy in doubtful diagnosis. Flexible esophagoscopy has a sensitivity close to 100%.
According to the obtained data in this study, CTA is advised as a routine tool in all cases of PNIs in HSPs. Additional evaluation using bronchoscopy, contrast swallow / flexible esophagoscopy may be directed by CTA results (11).

Management
In our series, 34.9 % of cases required no surgical intervention and were managed conservatively.
Nason et al. (34) and Van Waes et al. (17) concluded in two different studies that observation in asymptomatic patients is adequate in the first instance.
In this study, we followed the no zone approach for the management of PNIs because it was safe and feasible with few negative explorations and no missed injury (9,(35)(36)(37). Also, we avoided routine neck exploration and adopted planned customized surgical intervention according to the expected injuries in each case. Surgical intervention was done in 69 cases (65.09%). Statistical analysis showed that the no zone approach had a clinical and statistical significance in the management of PNIs in this study. Similar to Thoma et al. (35) who developed a management algorithm based on clinical examination and CTA for patients with PNI, we found that no surgical exploration was negative, and no injury was unnoticed. We think CTA is essential to guide surgical intervention. It is a fast, accurate, noninvasive method of evaluating PNIs in HSPs with improvement in the detectability of vascular injuries and extravascular injuries.

Management airways and laryngotracheal injuries
In our study, evaluation of laryngotracheal trauma was first assessed aiming to ensure a patent airway. If an injury of the laryngotracheal complex is expected, pan-endoscopy and bronchoscopy under general anesthesia should be done before surgical intervention (11,30). If an injury is detected, surgical repair is mostly indicated, except for minor mucosal tears or non-displaced fractures of the laryngeal skeleton, that can be treated conservatively (11). Major fractures and accompanying soft tissue lesions require open surgical repair (4).
In this study, tracheostomy was performed in 17 % of cases to establish patent airways. Also, laryngotracheal repair was done in 29.2% of cases. Jarviket al. (27) reported that laryngeal repair was required in 31% of cases. Nason et al. (34) found that airway repair was required in 37% of cases.
In accordance with other studies, tracheostomy was the preferred artificial airway. Tracheotomy was performed as low as possible to prevent further injury to the laryngotracheal complex. Most authors agree that blind intubation methods should be avoided in these circumstances because more injuries or complete airway obstruction may result (2,38,39). Tracheotomy was indicated if there was the skeletal collapse, partial or complete transection severe interruption of the laryngotracheal complex (26).

Management of vascular injuries
Saito et al. (30) reported that arterial injuries were reported in about 25% of PNIs; out of them, the carotid arteries were affected by 80%. In this study, the vascular injuries were detected in 40.57% of cases. With respect to the type of the involved vessel, the arteries were more involved than veins.
Isolated arterial injuries were found in 11.32% of the cases while isolated venous injuries in 6.6% in addition to the combined arterial & venous injuries (22.64%). The commonest form was incomplete transactions (21.7%), followed by complete transection (9.44%). Other less common injuries were thrombosed vessels (4.77%) or contusion with spasm (4.77%). In accordance with Bodanapally et al. (40) we find that all neck arteries are vulnerable to injury. In our study, we found that both CCA and ECA were equally affected (7.55%), while ICA was less affected (5.66%). Also, EJV injuries (11.32%) were more common than the IJV injuries (7.55%).

Management of pharyngo-esophageal injuries
In our study, pharyngeal repairs were done in 8 cases (7.55%), while esophageal repairs were performed in 7 cases (6.6%). The pharyngeal and esophageal injuries are uncommon because of their protected deep central location. They are difficult to detect as they have no clear clinical findings.
In our study, the injuries were debrided, and single-layer repair was performed with proper drainage and a sternomastoid muscle flap was utilized in large injuries or when there was associated tracheal or vascular injury (42). This is because all repairs of the carotid artery are liable to postoperative blowout if there has been an associated esophageal injury (43). Most of the studies advocate that singlelayer repair is equally safe and effective as a double-layer repair in PNIs. We agree that in the patients who show hard signs of pharyngeal / esophageal injury or if imaging investigations detect perforation, surgical repair is indicated (35). If not treated early, these injuries can lead to mediastinitis and abscess or empyema formation due to leakage of their contents (34).
Management of esophageal injuries is controlled by the time since the occurrence of injury. Patients attending within 12 hours of trauma may be subjected to immediate repair and drainage (34), while for those presenting after 12 hours, morbidity and mortality are high and immediate repair is more likely to be unsuccessful (34,36). These patients should undergo debridement and drainage with a planned delayed repair (27).

Complications and outcome
In this study, complications were noticed in 17 cases (16.04%). Infections were the commonest. They (1.9%), one had pharyngocutaneous fistula which healed three weeks after conservative treatment, and another one had a tracheoesophageal fistula. The later was subjected to unsuccessful operation for fistula repair and complicated by death. Neurological complications were reported in 8 cases (7.5%). Four cases got hoarseness voice and two cases had aphonia due to injuries to recurrent laryngeal nerves. They were referred to the speech clinic for further management. Two cases developed drop shoulder due to failure of the accessory nerve repair and they were sent to the physiotherapy department for treatment. Other complications were seen in 9 cases, eight cases developed either hypertrophic ugly scar or keloid and one patient had chylous fistula which was managed successfully by another surgery two months later.
In our study, the survivors were 97 (91.5%) while the number of deaths was 9 (8.5%). Demetriades et al. (3) reported that PNIs are associated with a mortality of 3-10% and 50% of these deaths were attributed to hemorrhage while esophageal injuries are associated with mortality rates of 11-17% (28).
In this study, more than two-thirds of deaths (6/9) were associated with vascular complications both the intraoperative and postoperative hemorrhage, followed by infections where death occurred in 2 cases; one case with neck infection and descending mediastinitis and another with aspiration pneumonitis. Pharyngoesophageal complications were related to the least mortality where death was reported in a case with tracheoesophageal fistula. Others reported that vascular injuries were associated with half the mortality cases. tracheal injury was responsible for about one fifth the mortalities (32). Also, esophageal injuries can lead to leakage of swallowed materials into surrounding tissues with sepsis and death (44).

Conclusion
The no-zone approach offers the ideal management for isolated PNIs in HSPs. CTA is advised as a routine tool in all cases. Additional evaluation using bronchoscopy, contrast swallow/flexible esophagoscopy may be directed by the CTA results. The commonest injuries were the vascular injuries which were associated with higher morbidity and mortality. Data is gathering to advocate that