Adrenal Gland Trauma: An Observational Descriptive Analysis from a Level 1-Trauma Center.

INTRODUCTION: We aimed to describe the presentation, classification, and outcome of traumatic adrenal injury in a single Level-1 trauma center.
METHODS: A retrospective study was conducted to include all patients identified to have adrenal trauma from 2011 to 2014. Data were retrieved from charts and electronic medical records for all patients with adrenal trauma with a 3-year follow-up for mortality.
RESULTS: A total of 116 patients who were admitted with adrenal injury (12.9% of abdominal trauma and 20% of total solid organ injury admissions) were included in the study, 104 were males and 12 were females. In our population, 86% of adrenal injuries involved the right adrenal gland, 14% in the left, and 12% had bilateral injuries. The majority of associated injuries were rib fractures accounting for 42%, while 37% had associated lung injuries, and 35% had head injuries. As per the American Association for the Surgery of Trauma classification, 46% of adrenal traumas were grade one. Of all adrenal trauma, 25 patients were operated (21%), whereas the majority were admitted to the intensive care unit or surgical ward. Surgical interventions were indicated for associated injury to the bowel, spleen, diaphragm, mesentery, kidneys, or inferior vena cava. One patient underwent angioembolization of the adrenal vessels due to contrast leak. The mortality rate was 14.6%, and no further mortality was reported during a 3-year follow-up. On multivariable analysis, admission systolic blood pressure, Glasgow Coma Scale, and injury severity score were predictors of hospital mortality.
CONCLUSIONS: Adrenal injury is not rare and often unilateral with right-sided predominance. Associated injuries influence the clinical findings, management, and outcome. Surgical interventions are rarely required except for few cases of active bleeding. Long-term outcome postadrenal injury is still not well studied. Copyright:

INTRODUCTION

Traumatic adrenal injury is relatively rare due to the deep location of the adrenal gland in the retroperitoneal cavity while being well protected and cushioned with multiple surrounding soft tissues.[1] There is an increase in the rate of identification of traumatic adrenal injury due to the prevalent use of abdominal computed tomography (CT) in trauma patients.[2] Adrenal trauma is reported in 0.15%–4% of blunt abdominal trauma cases and is unilateral in 75%–90% of cases with right-sided predominance.[1345]

The majority of cases of adrenal trauma do not display specific signs and symptoms; however, the presence of adrenal trauma may indicate the presence of severe trauma and should prompt an evaluation for associated injuries.[5] Due to the possible life-threatening events associated with adrenal injuries, several authors have advised aggressive management and early intervention to avoid complications such as delayed adrenal insufficiency.[56] In contrast, an increasing number of studies have reported that conservative management can be used for patients with adrenal trauma.[34]

Due to the rarity of adrenal trauma cases, it is difficult to conduct a large study on the significance of this injury. In the current study, we intend to review the incidence, management, and outcome of adrenal trauma and to identify the classification of adrenal trauma and factors that necessitate intervention.

METHODS

A retrospective study was conducted to include all patients identified to have adrenal trauma during the time period from June 2011 to June 2014. All patients were admitted through the Trauma Resuscitation Room in Hamad General Hospital that is the only tertiary trauma center in Qatar that receives 1500–1600 trauma admissions per year. Data were retrieved from the trauma database registry, surgical charts for all patients with adrenal trauma. Collected data included demographics, mechanism of injury, associated solid-organ injuries (SOIs), diagnostic workup-based radiological findings, indications for surgical intervention, complications, and outcomes. A 3-year follow-up of mortality was reported.

All patients with adrenal gland trauma were managed by the trauma team from the time of emergency department arrival to discharge. The diagnosis of adrenal trauma was made based on the CT images for all patients included in the study.

Ethical approval was obtained and a waiver of informed consent was granted from Research Ethics Committee at the Medical Research Center, Hamad Medical Corporation (HMC), Doha, Qatar (Institutional Review Board [IRB]# 14409/14). There was no direct contact with patients, and data were kept anonymously for patients' privacy and confidentiality. This study follows the Strengthening the Reporting of Observational Studies in Epidemiology checklist of items that should be included in reports of observational studies

Statistical analysis

Statistical analysis data were presented as proportions, mean ± standard deviation, median, and interquartile range in normally and nonnormally distributed variables whenever applicable. For laterality of the injured adrenal gland, data were compared among left, right, and bilateral injury using Chi-square test and analysis of variance test. Multivariable analysis was performed for predictors of mortality in adrenal trauma using relevant variables as age, admission systolic pressure, admission Glasgow Coma Scale (GCS), injury severity score (ISS), and surgical intervention. Data were expressed using odd ratio and 95% confidence interval. Two-tailed P < 0.05 was considered a statistically significant difference. All data analyses were carried out using the Statistical Package for the Social Sciences version 18 (SPSS Inc., Chicago, IL, USA).

RESULTS

Across the study period, around 4500 patients with trauma were admitted, of them 900 patients had an abdominal injury (20%). A total of 116 patients (12.9% of abdominal trauma admissions and 20% of the total SOI) were included in the study with the diagnosis of adrenal trauma [Figure 1]. The mean age for patients diagnosed with adrenal trauma was 32.5 ± 13.7 years, with males comprising the majority (90%) of the population. All patients sustained blunt trauma. Table 1 shows the basic demographics ofthe study population. The mechanism of injury for the patients diagnosed with adrenal trauma was skewed toward road traffic-related injuries that accounted for 67% of the study group and 20% fall from height. The median ISS of the study group was 36 (27–38). Rib fractures were the most associated injuries with adrenal trauma accounting for 42%, while 37% and 35% had associated lung and head injuries, respectively. Of solid-organ injuries, 47% had liver injuries, 23% had spleen injury, and 22% had kidney injury, while 21% had pelvic injuries. Table 1 shows the details of the mechanism of injuries and associated injuries.

Figure 1

Flowchart of the study design

Table 1

Demographic characteristics and presentation of adrenal injury

Variable	Value (%)	CI (%)
Age (years)	32.5	29.98-35.02
Gender
Males	104 (89.66)	82.63-94.54
Female	12 (10.34)	5.46-17.37
Mechanism
MVC related	78 (67.24)	57.91-75.67
Fall from height	24 (20.69)	20.69-87.93
Fall of heavy objects	5 (4.31)	1.41-9.77
ATV	3 (2.59)	0.54-7.37
Other	6 (5.17)	1.92-10.92
Injury severity score	36	27-38
Associated injuries
Lung	43 (37.07)	28.29-46.53
Head	41 (35.34)	26.69-44.76
Hemothorax	11 (9.48)	4.83-16.33
Pneumothorax	26 (22.41)	15.19-31.09
Hemopneumothorax	18 (15.52)	9.46-23.41
Rib fracture	49 (42.24)	33.13-51.76
Bowel	13 (11.21)	6.10-18.40
Liver	55 (47.41)	38.07-56.89
Kidney	26 (22.41)	15.19-31.09
Pancreas	10 (8.62)	4.21-15.28
Spleen	27 (23.28)	15.93-32.03
Spine injury	16/113 (14.16)	8.32-21.97
Pelvic fracture	24/113 (21.24)	14.11-29.93

CI: Confidence interval, MVC: Motor vehicle crash, ATV: All-terrain vehicle

In our population, 86% of the adrenal injuries involved the right adrenal gland, 14% were in the left gland, and 12% had bilateral injuries. The most common CT finding of adrenal trauma was oval or round hematoma (31.1%). Table 2 depicts the details of the adrenal injuries and the CT findings.

Table 2

Characteristics of adrenal injury

Variables	Values (%)	CI (%)
Adrenal hematoma
Yes	111 (95.69)	90.23-98.59
No	5 (4.31)	1.41-9.77
Left	14/100 (14)	7.87-22.37
Right	86/100 (86)	77.63-92.13
Bilateral	13/113 (11.50)	6.27-18.87
Mass	5/113 (4.42)	1.45-10.02
Blush	16/116 (13.79)	8.09-21.43
CT classification findings
Focal hematoma	19/106 (17.92)	11.15-26.57
Gross adrenal hemorrhage	87/106 (82.08)	73.43-88.85
Focal hematoma
Indistinct adrenal gland	7/106 (6.6)	2.70-13.13
Enlarged adrenal gland	12/106 (11.32)	5.99-18.94
Most common imaging features
Round or oval hematoma expanding the adrenal gland	33/106 (31.13)	22.49-40.86
Irregular hemorrhage obliterating the adrenal gland	27/106 (25.47)	17.51-34.86
Periadrenal hemorrhage or fat stranding	25/106 (23.58)	15.88-32.82
Uniform adrenal swelling with increased attenuation	11/106 (10.38)	5.30-17.81
Diffuse hemorrhage in the adjacent retroperitoneum	10/106 (9.43)	4.62-16.67
Contusion	49/106 (46.23)	36.49-56.18
Cortex laceration <2 cm	4/106 (3.77)	1.04-9.38
Laceration extending into medulla >2 cm	28/106 (26.42)	18.32-35.87
>50% parenchymal destruction	24/106 (22.64)	15.08-31.79
Total parenchymal destruction/massive intraparenchymal hemorrhage avulsion from blood supply	1/106 (0.94)	0.02-5.14

CT: Computed tomography, CI: Confidence interval

As per the American Association for the Surgery of Trauma (AAST) classification, 46% of the adrenal traumas were Grade I, while 22.6% of injuries showed severe (>50%) parenchymal destruction, as seen in Table 2. Of 116 patients with associated adrenal trauma, 25 patients were operated (21%) and the majority was admitted to either intensive care unit (ICU) or in the ward (44.9% and 34.8%, respectively) without surgical intervention. In the operated group, the reasons included injury to the bowel, spleen, diaphragm, mesentery, kidneys, or inferior vena cava (IVC). One patient had undergone angioembolization of the adrenal vessels due to contrast leak. The majority of the study population received a blood transfusion, with a median 5 units (range: 1–54). The mortality rate was 14.6%. A 3-year follow-up revealed no further mortality. The average length of hospital stay was 21 days and average ICU admission days were 9 days. The clinical course and outcome for patients with adrenal trauma are shown in Table 3. Patients with left adrenal injury had higher abdominal abbreviated injury scale. Patients with right adrenal injury were more males and had a higher rate of associated liver injury. Patients with bilateral gland injury had higher ISS, more head injury, longer stay in the ICU, more surgical intervention, and higher mortality, as shown in Table 4. On multivariable analysis, admission systolic blood pressure, GCS, and ISS were the predictors of hospital mortality [Table 5].

Table 3

Clinical course and outcome in patients with adrenal trauma

Variables	Values (%)	CI (%)
ED disposition
Operating room	25 (21.55)	14.46-30.15
Intensive care unit	51 (43.97)	34.76-53.48
Trauma floor	40 (34.48)	25.90-43.88
Outcome
Dead	17 (14.66)	8.78-22.42
Alive	99 (85.34)	77.58-91.22
Blood transfusion	55/59 (93.22)	83.54-98.12
Blood units	8.29±8.5	5.99-10.59
Hospital length of stay (days)	21.50	12-37*
ICU admission days	9.50	4-22*
Ventilator days	5	3-9*

*Reported in median and IQR. ICU: Intensive care unit, ED: Emergency department, CI: Confidence interval

Table 4

Comparison of clinical presentation and outcome by site of adrenal injury (n=113)

	Bilateral injury (n=13)	Left adrenal injury (n=14)	Right adrenal injury (n=86)	P
Age	33.7±18.2	39.5±16.2	31.3±12.4	0.11
Gender (males), n (%)	11 (84.6)	10 (71.4)	80 (93.0)	0.04
Associated injury, n (%)
Head	9 (69.2)	4 (28.6)	27 (31.4)	0.06
Bowel	1 (7.7)	3 (21.4)	9 (10.5)	0.75
Liver	4 (30.8)	1 (7.1)	48 (55.8)	0.005
Spleen	3 (23.1)	7 (50.0)	17 (19.8)	0.10
Kidney	6 (46.2)	4 (28.6)	16 (18.6)	0.17
Pancreas	2 (15.4)	3 (21.4)	5 (5.8)	0.33
Pelvic fracture	2 (15.4)	4 (28.6)	18 (20.9)	0.92
Rib fracture	3 (23.1)	8 (57.1)	38 (44.2)	0.36
Lung contusion	9 (69.2)	4 (28.6)	28 (32.6)	0.07
Injury severity score	30.0±11.5	25.1±12.8	20.5±11.3	0.01
Head AIS	4.0±1.3	4.2±0.9	3.8±0.9	0.63
Chest AIS	2.82±0.75	2.83±0.38	2.77±0.56	0.91
Abdominal AIS	2.46±0.87	3.00±1.35	2.31±0.80	0.03
Surgery for other injury, n (%)	4 (30.8)	5 (35.7)	8 (9.3)	0.04
Adrenal hematoma, n (%)	13 (100)	12 (85.7)	83 (96.5)	0.13
>50% parenchymal destruction, n (%)	5 (45.5)	4 (33.3)	15 (18.1)	0.36
Blood transfusion, n (%)	10 (76.9)	6 (42.9)	38 (44.2)	0.08
ICU length of stay	16 (2-37)	4.5 (1-9)	6 (6-42)	0.01
Hospital length of stay	27 (6-42)	12 (3-28)	11 (1-132)	0.14
Mortality, n (%)	5 (38.5)	3 (21.4)	9 (10.5)	0.07

AIS: Abbreviated Injury scale

Table 5

Multivariable analysis for predictors of mortality in adrenal trauma

Variable	P	OR	95% CI
Age	0.125	1.060	0.984-1.143
Injury severity score	0.040	1.120	1.005-1.248
Admission systolic blood pressure	0.017	0.949	0.909-0.991
Admission Glasgow coma scale	0.014	0.785	0.647-0.953
Surgical intervention	0.099	5.885	0.714-48.480

OR: Odd ratio, CI: Confidence interval

DISCUSSION

This is a descriptive study from the Arab Middle East that assesses the traumatic adrenal injury in a Level-1 trauma center. It shows that adrenal injury represents 1–8 of all the abdominal trauma admissions and 1–5 of all SOI with high mortality that mainly related to the associated injuries. The higher prevalence of adrenal trauma in our study could be related to the advance of imaging use and the higher rate of blunt trauma. This study also reported that the associated injuries in adrenal trauma play a substantial role in the presentation, management, and outcome. Admission systolic blood pressure, GCS, and ISS were the predictors of hospital mortality. Although bilateral adrenal gland injury was the least common in our cohort, it had significant clinical characteristics and worse outcomes in comparison to the unilateral (right and left) adrenal injury. A recent study from the United Arab Emirates, which is a neighbor country, reported only 11 cases (all males) with blunt adrenal injury (0.22%) over more than 7 years.[7] Three theories of adrenal trauma from blunt injury have been proposed. First, during the abdominal impact, there is compression on the IVC that will consequently increase the intra-adrenal venous pressure causing adrenal trauma and acute hemorrhage that may be the reason for the higher incidence of right-sided adrenal gland due to the short right adrenal vein directly draining into the IVC.[6] Second, adrenal injury is caused by the crushing of the adrenal gland between the spine and the surrounding organs such as the liver or spleen. This theory can explain the commonly witnessed occurrence of ipsilateral organ injuries that may indicate the severity of the trauma. Third, deceleration forces shear the sinusoidal network of small arterioles in the adrenal gland.[48] During stressful trauma, catecholamine secretion increases; this increase stimulates the adrenal arterial blood flow, exceeding the limited venous drainage capacity and leading to hemorrhage.[9]

The treatment of adrenal gland injury depends on the severity of the injury, contralateral gland status, viability of residual tissue, and the patient's general condition. Most patients can be treated conservatively, but surgical therapy is indicated when active bleeding is evident.[10]

In our series, active blush or extravasation was seen in 16 patients (13.79%). Gross adrenal hemorrhage was seen in 87 patients (82.08%). Similarly, in a study conducted by Liao et al.,[11] the authors assessed 60 patients diagnosed with adrenal trauma, of which 53% had extravasation of contrast. In the extravasated group, there was a higher ISS and greater grade of adrenal trauma. Fifty-five patients required blood transfusion due to ongoing hemorrhage and one patient who had active extravasation or gross hemorrhage of the adrenal gland on CT scan that required angioembolization. Thus, extravasation or adrenal hemorrhage has high-gradeassociated organ injuries.[11] In the present study, more than half of the patients were treated successfully using conservative management. Similarly, Sang Lee et al. evaluated 11 patients with blunt adrenal injury and all patients except one were successfully managed conservatively (90% success rate with conservative management).[512]

The mortality rate was 14.6%, but the majority of these patients had a severe associated injury and higher grade adrenal trauma leading to death. Of patients with adrenal injury, one-fifth had pelvic injuries, 54% had Grade I AAST pelvic fracture, while 22% had Grade IV. A similar pattern was seen with splenic injuries where 22% of Grade IV splenic injuries had associated adrenal injury.

In 2003, Stawicki et al.[8] reported 322 (0.15%) adrenal injury cases over 11 years, 71% of them had severe injury with ISS >20 and high mortality of 32.6%. In 2007, Mehrazin et al. identified 130 (0.22%) adrenal injury cases over 15 years; they concluded that adrenal injury is mostly associated with high injury severity but not require interventions.[10] On the other hand, there are two reports by DiGiacomo et al. from New York, concluding that adrenal gland injuries are not associated with higher ISS or an increased risk of mortality.[1314] In the first study, they identified 72 adrenal injury cases over 15 years; the mean ISS of the adrenal injury group was severe but comparable to the nonadrenal injury group (18.7 vs. 17.1); and the mortality was also comparable in the two groups. In their second study, they identified 317 adrenal injury cases compared to 5125 patients with nonadrenal abdominal organ injury. In the adrenal injury group, 61% had ISS >16 in comparison to 63% of the other group. This indicates that adrenal injury patients may have high ISS but similar to that of nonadrenal injury patients.

Limitations

Our study is a retrospective, which is one of the limitations. In addition, the biomarker screening for adrenal function in the unilateral and bilateral injury was lacking in the study both on the initial admission and upon follow-up, so it is challenging to predict the severity or the long-term outcome and whether patients have developed adrenal insufficiency or not. Future prospective studies should be done to look into the biomarker levels for the adrenal trauma patient and correlate it with the severity of the injury and outcomes, both short and long term.

The current adrenal injury classification or grading did not efficiently guide the decision-maker for management and prognosis. A more reliable and accurate scoring system of adrenal trauma should be addressed in future studies. The absence of data on the prior history of adrenal disorders is also a limiting factor, as preexisting adrenal diseases could predispose the adrenal to get injured even with mild trauma.[5]

CONCLUSIONS

Adrenal trauma is not rare in blunt abdominal trauma and is often unilateral with right-sided predominance. Associated injuries influence the clinical findings, management, and outcome. Adrenal injury-related intervention (whether surgical or angioembolization) is rarely required except for few cases of active bleeding. The long-term outcomes still are not well studied.

This paper was presented in part at the European Society for Trauma and Emergency Surgery ECTES 6–8 May 2018 Valencia, Spain.

Research quality and ethics statement

This study was approved by the Institutional Review Board / Ethics Committee (HMC, Medical Research Center IRB# 14409/14). The authors followed applicable EQUATOR Network () guidelines during the conduct of this research project.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest