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Traumatic renal injury: Five-year experience at a major trauma centre in South Africa
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Traumatic renal injury: Five-year experience at a major trauma centre in South Africa M.S. Salem a, R.J. Urry b,∗, V.Y. Kong c,d, D.L. Clarke c,d, J. Bruce d, G.L. Laing d a
Department of Urology, University of KwaZulu-Natal, Durban, South Africa Department of Urology, Sefako Makgatho Health Sciences University, Ga-Rankuwa, South Africa c Department of Surgery, University of the Witwatersrand, Johannesburg, South Africa d Department of Surgery, University of KwaZulu-Natal, Durban, South Africa b
a r t i c l e
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Article history: Accepted 14 October 2019 Available online xxx Keywords: Renal trauma Kidney trauma Abdominal trauma Blunt trauma Penetrating trauma Traumatic renal injury
a b s t r a c t Background: This study is intended to assess the current optimal management of traumatic renal injuries (TRIs), with a focus on high-grade and penetrating injuries. Methods: The Pietermaritzburg Metropolitan Trauma Service registry was interrogated retrospectively for patients managed for TRI between 1 January 2012 and 31 December 2016. Results: Of 13,315 inured patients treated by the PMTS, 223 (1.7%) had TRIs with an incidence of 1.5 per 10 0,0 0 0 population per year. The majority were males between 20 and 39 years of age. The distribution of mechanism of injury was 56.1% (n = 125) blunt and 43.9% (n = 98) penetrating trauma with no association between mechanism and grade of injury. Penetrating trauma was associated with hollow viscus and diaphragm injuries and blunt trauma with solid organ injuries. A total of 118 patients (52.9%) were managed non-operatively, 60 (26.9%) were not explored at operation, 27 (12.1%) underwent initial nephrectomy and 8 (3.6%) underwent renorraphy. Low-grade injuries (AAST I and II) and highgrade injuries (AAST III-V) were managed without renal intervention (non-operatively or not explored at laparotomy for associated injuries) in 88.7% (n = 87) and 72.0% (n = 91) of cases respectively. Blunt and penetrating injuries were managed without renal intervention in 87.9% (n = 109) and 70% (n = 69) of cases respectively. The initial nephrectomy rate was 1% (n = 1) and 20.6% (n = 26) for low- and high-grade injuries respectively, and 6.5% (n = 8) and 19% (n = 19) for blunt and penetrating injuries respectively. High grade (AAST III-V) injury (OR 14.94; 95% CI 3.36 – 66.34; p<0.001), penetrating mechanism (OR 4.99; 95% CI 1.98 – 12.52; p = 0.001) and metabolic acidosis (OR 2.73; 95% CI 1.04 – 7.20; p = 0.042) were significant risk factors for nephrectomy. Four patients (1.8%) underwent ureteral stent insertion and 2 (0.9%) underwent embolisation. The failure rate of initial non-operative management was 1.1%. The mortality rate was 8.1% (n = 18), but no patients with solitary renal injuries died. Conclusion: Even in high-grade injuries and penetrating trauma, the majority of patients with TRI can be managed non-operatively or with the assistance of endourological or endovascular techniques, with good outcomes. Risk factors for nephrectomy include the presence of high-grade injuries, penetrating trauma and metabolic acidosis on presentation. © 2019 Elsevier Ltd. All rights reserved.
Introduction Injury remains a significant problem in South Africa with urogenital injuries occurring in approximately 10% of trauma patients and TRIs occurring in 1–5% of trauma patients [1,2,3,4]. South African surgeons have acquired a large and sustained experience in the management of trauma, and the development of electronic databases in trauma centres such as ours over the last decade, has ∗ Corresponding author. Suite 211, South Block, Netcare Waterfall City Hospital, Midrand, Johannesburg, South Africa, 1682. E-mail address: [email protected] (R.J. Urry).
facilitated the documentation of this experience. Globally, over the last half century, there has been a move towards surgical minimalism and non-operative management (NOM) in trauma and these non-operative approaches have been applied successfully to traumatic renal injuries (TRIs). Increasing experience and success with NOM has resulted in it being applied to higher grades of TRI. Currently, NOM of low-grade, blunt TRI is widely accepted as the standard of care. However, NOM for high-grade TRI and penetrating injuries is less well defined. In light of these developments and controversies, this study set out to review our experience with TRI, define the spectrum and outcome of TRI in our setting, and interrogate the role of NOM in the management of these injuries. A
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Please cite this article as: M.S. Salem, R.J. Urry and V.Y. Kong et al., Traumatic renal injury: Five-year experience at a major trauma centre in South Africa, Injury, https://doi.org/10.1016/j.injury.2019.10.034
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particular focus was placed on high-grade TRIs and penetrating injuries in order to clarify the role and indications for NOM in these more severe and destructive renal injuries. It is hoped that this data will refine management strategies for TRI.
Methods Management of TRI The Pietermaritzburg Metropolitan Trauma Service (PMTS) is a tertiary level major trauma centre located in Pietermaritzburg, the capital city of the KwaZulu-Natal (KZN) province of South Africa. The service covers 19 district hospitals in KZN with a catchment population of approximately 3 million people. TRI is managed primarily by trauma surgeons whilst more complex injuries requiring more specialized urological intervention are managed in conjunction with the Urology service. Patients are managed according to standard trauma protocols: •
•
•
•
•
All patients with abdominal trauma, blunt or penetrating, are resuscitated. Non-responders as well as patients with penetrating injuries who are peritonitic are expedited to the operating room (OR). The remainder undergo an abdominal CT scan and all injuries are graded according to the American Association for the Surgery of Trauma (AAST) grading system [5]. Patients with blunt TRI who continue to respond to resuscitation and who do not have a completely devascularised kidney are treated with NOM. The grade of the injury is not in itself an indication for surgery. These patients are re-imaged selectively. If there is ongoing haemtauria or a urinary leak, they are managed by angiographic embolisation or endourological drainage. Patients with penetrating abdominal trauma are managed according to a selective approach. Patients who do not have an indication for urgent operative management are admitted and observed. At laparotomy, perinephric haematomas are not routinely explored unless there is compelling evidence that there is active bleeding (for example, an expanding lateral retroperitoneal haematoma). In the event of exploration, attempts may be made to repair the TRI if it is low grade and the patient is stable. However, if the injury is high-grade (AAST III-V) or if the patient’s physiology is compromised, nephrectomy is generally performed. The protocol for NOM includes admission, bed-rest, regular monitoring of vital signs, regular physical abdominal examination, and regular haemoglobin and haematocrit assessment [6].
Data collection The PMTS prospectively collects data for the purpose of research and auditing using a prospective hybrid electronic medical registry (HEMR) [7]. In terms of the urogenital system, traumatic bladder injuries [8] and combined colon and renal injuries [9] have already been described using this registry. The registry was interrogated retrospectively, and all patients diagnosed with a TRI between January 2012 and December 2016 were identified. Demographic data, mechanism of injury, grade of injury, accompanying injuries, management and outcome were assessed. Mechanism of injury was classified into blunt, including road traffic accidents (RTAs), pedestrian vehicle accidents (PVAs), assaults, falls and other causes; and penetrating, including stab wounds (SWs), gunshot wounds (GSWs) and other causes. Ethics approval for the study was granted by the Biomedical Research Ethics Committee (BREC) of the University of KwaZulu-Natal (BE642/16 and BCA221/13).
Fig. 1. Age distribution of patients with TRI.
Statistical analysis Statistical analyses were performed using the Statistical Package for Social Sciences (SPSS) version 24 (IBM, USA). The incidence of TRI was calculated in terms of the number of injuries per 10 0,0 0 0 population per year. Comparison of means was performed using the t-test for equality of means in independent samples. Pearson’s χ 2 test with Yates’ correction for continuity [10] was used to compare categorical variables. If the projected frequency, assuming a true null hypothesis, in a cell of a two-by-two table was less than five observations, Fisher’s exact test was applied using double the one-tailed exact probability [10]. Univariable logistic regressions were performed to determine the odds ratio for risk factors for nephrectomy. Each significant finding was checked using Pearson’s χ 2 test with Yates’ correction for continuity and the corrected significance reported. Significant risk factors were further analysed using a multivariable regression, with each variable entered into the model simultaneously (i.e. non-stepwise), and variables with a significant impact on the odds ratio of the dependant variable identified as risk factors. A p-value <0.05 (5%) was considered statistically significant. Results During the period under review, 13,315 injured patients were admitted by the PMTS. Of these, 348 patients (2.6%) had urological injuries. There were 223 renal injuries, accounting for 64.1% of urological injuries and 1.7% of all trauma cases. The kidney was the commonest urological organ injured, followed by the bladder (27.0%; n = 94), urethra (5.4%; n = 19) and ureters (3.4%, n = 12). The incidence of injury requiring hospital treatment was 88.8 per 10 0,0 0 0 population per year, and of TRI 1.5 per 10 0,0 0 0 population per year. Demographic data The mean age of patients with TRI was 27 years (SD 11.4 years; range 2–69 years). Thirty-five patients (15.7%) were under the age of 18 years. The majority (n = 181; 81.2%) were male and between the ages of 20 and 39 years. Fig. 1 demonstrates the age distribution of patients with TRI. Mechanism of injury The mechanism of injury is illustrated in Fig. 2. The blunt injuries not classified included those caused by animals, structural collapse, falling trees and falls from tractors. Of the patients younger than 18 years of age, 89% (n = 31) sustained blunt trauma with falls and PVAs the commonest cause and 11% (n = 4) sus-
Please cite this article as: M.S. Salem, R.J. Urry and V.Y. Kong et al., Traumatic renal injury: Five-year experience at a major trauma centre in South Africa, Injury, https://doi.org/10.1016/j.injury.2019.10.034
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Total Traumac Renal Injuries n=223
Blunt trauma n=125 (56.1%)
Penetrang trauma n=98 (43.9%)
Other Falls 4.8% 12.8% RTAs 43.2%
Assualts 10.4%
GSWs 48.0%
SWs 52.0%
PVAs 28.8% Fig. 2. Summary of the mechanism and causes of TRIs.
30.0 25.0 10.3
20.0 15.0
7.2
13.0
Penetrang (%) 15.2
10.0
8.5
13.0 10.3
5.0
4.9
8.5
9.0
Grade IV
Grade V
Blunt (%)
0.0 Grade I
Grade II
Grade III
Fig. 3. Distribution of TRI by mechanism and AAST grade.
tained penetrating trauma. Patients younger than 18 years were significantly less likely to sustain penetrating trauma (p<0.001). Diagnosis Diagnosis of TRI was made by multiphase abdominal computed tomography (CT) scan with intravenous contrast in stable patients (n = 188; 84.3%) and intra-operatively in unstable patients who were taken directly from the emergency room to the operating room (n = 35; 15.7%). Laterality and grade of injury The left kidney was injured in 51.8% (n = 87), the right kidney in 44.6% (n = 75) and both kidneys in 3.6% (n = 6) of cases. The six patients with bilateral injuries all suffered blunt trauma and were either involved in RTAs or PVAs. The grade of renal injury, according to the AAST kidney injury scale is illustrated in Fig. 3. There
was no significant association between mechanism and high-grade TRI (p = 0.598). Associated injuries The frequency of associated injuries compared by mechanism is summarized in table 1. Isolated renal injury occurred in 70 cases (31.5%) and was not significantly associated with either penetrating or blunt trauma (p = 0.485). Accompanying hollow viscus injuries (stomach, small intestine and colon) as well as diaphragm injuries were significantly associated with penetrating trauma. Accompanying solid organ injuries, particularly liver, spleen and adrenal injuries, were significantly associated with blunt trauma. Injury to other urogenital organs were not likely to accompany TRI. Management Most TRIs were initially managed non-operatively. They were either subjected to NOM primarily (n = 118; 53.2%) or were not
Please cite this article as: M.S. Salem, R.J. Urry and V.Y. Kong et al., Traumatic renal injury: Five-year experience at a major trauma centre in South Africa, Injury, https://doi.org/10.1016/j.injury.2019.10.034
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In one patient, the AAST grade of injury could not be determined and this patient was not included in the analysis. †
Total
Penetrating Blunt
98 79.0% 0 0.0% 8 6.5% 3 2.4% 1 0.8% 11 8.9% 3 2.4% 124 100.0% 3 27.3% 0 0.0% 5 45.5% 0 0.0% 0 0.0% 3 27.3% 0 0.0% 11 100.0%
Penetrating Blunt
14 70.0% 0 0.0% 5 25.0% 0 0.0% 0 0.0% 1 5.0% 0 0.0% 20 100.0% 8 42.1% 0 0.0% 7 36.8% 0 0.0% 1 5.3% 3 15.8% 0 0.0% 19 100.0%
Penetrating Blunt
15 78.9% 0 0.0% 2 10.5% 1 5.3% 1 5.3% 0 0.0% 0 0.0% 19 100.0% 3 13.0% 3 13.0% 6 26.1% 1 4.3% 0 0.0% 10 43.5% 0 0.0% 23 100.0%
Penetrating Blunt
29 85.3% 0 0.0% 1 2.9% 1 2.9% 0 0.0% 2 5.9% 1 2.9% 34 100.0% 4 13.8% 4 13.8% 0 0.0% 0 0.0% 0 0.0% 21 72.4% 0 0.0% 29 100.0% Abdominal operation but no renal exploration Unknown
The mortality rate of patients with TRI was 8.1% (n = 18). Of patients with low grade injuries, 3.1% (n = 3) died and of patients with high grade injuries, 11% (n = 14) died (p = 0.048). No patients
Embolisation of kidney
Outcomes
Insertion of JJ stent
In four patients (1.8%) a JJ-stent was inserted as a separate procedure and 2 patients (0.9%) were referred to interventional radiology for embolisation of a bleeding kidney.
Surgical exploration and repair of kidney Nephrectomy
Need for additional procedures
Penetrating
Twenty-seven patients (12.2%) underwent initial nephrectomy. High grade injuries (p<0.001) and penetrating injuries (p = 0.002) were significantly associated with nephrectomy. The highest initial nephrectomy rates were seen in grades III, IV and V penetrating injuries (26.1%, 36.8% and 45.5% respectively). The initial nephrectomy rate was 1% (n = 1 of 96) and 20.6% (n = 26 of 126) for low- and high-grade injuries respectively, and 6.5% (n = 8) and 19% (n = 19) for blunt and penetrating injuries respectively. Two patients (1.1% of all patients and 2.9% of patients with penetrating injuries, not subjected to nephrectomy) underwent delayed nephrectomy. Analysis of risk factors for nephrectomy (initial and delayed) is summarized in table 3. On multivariable regression analysis, high grade (AAST III-V) injury (OR 14.94; 95% CI 3.36 – 66.34; p<0.001), penetrating mechanism (OR 4.99; 95% CI 1.98 – 12.52; p = 0.001) and base deficit greater than 6 (OR 2.73; 95% CI 1.04 – 7.20; p = 0.042) were significant risk factors for nephrectomy.
16 69.6% 0 0.0% 0 0.0% 1 4.3% 0 0.0% 5 21.7% 1 4.3% 23 100.0%
Nephrectomy
Blunt
explored at the time of laparotomy for other associated injuries (n = 60; 27.0%). Eight patients (3.6%) underwent renorraphy, all with penetrating injuries, and 27 (12.2%) underwent nephrectomy. The initial management according to AAST kidney injury scale and mechanism of injury is presented in table 2. Low-grade injuries (AAST I and II) and high-grade injuries (AAST III-V) were managed without renal intervention (non-operatively or not explored at laparotomy for associated injuries) in 91% (87/96) and 72.2% (91/126) of cases respectively. Blunt and penetrating injuries were managed without renal intervention in 87.9% (109/124) and 70% (69/98) of cases respectively. Intervention was significantly associated with high grade injuries (p<0.001) and penetrating injuries (p<0.001).
2 12.5% 1 6.3% 1 6.3% 0 0.0% 0 0.0% 12 75.0% 0 0.0% 16 100.0%
Bold indicates a significant finding. ∗ Indicates that Fisher’s Exact Test was applied using double the onetailed exact probability. † The column count may exceed the total as some patients had multiple injuries.
Penetrating
0.001 0.025 0.877 0.048∗ 0.001 0.684∗ 0.002 <0.001 – 1.000∗ 0.808∗ <0.001 0.388∗
Blunt
22 (22%) 17 (17%) 8 (8%) 1 (1%) 14 (14%) 6 (6%) 13 (13%) 33 (34%) 0 (0%) 0 (0%) 1 (1%) 16 (16%) 2 (2%)
Total†
55 (44.4%) 39 (31.5%) 12 (9.7%) 9 (7.3%) 2 (1.6%) 5 (4.0%) 2 (1.6%) 4 (3.2%) 0 (0%) 1 (0.8%) 3 (2.4%) 2 (1.6%) 0 (0%)
AAST V
77 (34.7%) 56 (25.2%) 20 (9.0%) 10 (4.5%) 16 (7.2%) 11 (5.0%) 15 (6.8%) 37 (16.7%) 0 (0%) 1 (0.5%) 4 (1.8%) 18 (8.1%) 2 (0.9%)
AAST IV
p-Value
Liver Spleen Pancreas Adrenal Stomach Duodenum Small Intestine Colon Rectum Ureter Bladder Diaphragm IVC
AAST III
Penetrating (n = 98)
AAST II
Blunt (n = 125)
AAST I
Total (n = 223)†
Table 2 Initial management of TRI classified by AAST kidney injury scale and mechanism, showing number and percentage management within each grade and mechanism.
Organ
24 85.7% 0 0.0% 0 0.0% 0 0.0% 0 0.0% 3 10.7% 1 3.6% 28 100.0%
Table 1 Frequency of accompanying injuries and comparison by mechanism.
20 20.4% 8 8.2% 19 19.4% 1 1.0% 1 1.0% 49 50.0% 0 0.0% 98 100.0%
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Non-operative
4
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Table 3 Results of univariate logistic regression to identify risk factors for nephrectomy (initial and delayed).
Parameter
Nephrectomy patients (n = 29)
No-nephrectomy patients (n = 193)
OR (95% CI)
p-Value
Age in years† High grade (AAST III-V) injury Penetrating mechanism Accompanying injuries SBP <90 mmHg on presentation HR on presentation† Hb < 10 g/dL on presentation Base deficit < 6 Lactate > 4 mmol/L
– 27 (93%) 21 (72%) 6 (21%) 4 (13%) – 11 (38%) 10 (35%) 5 (17%)
– 98 (50.8%) 77 (39.9%) 64 (33.2%) 8 (4.1%) – 39 (20.2%) 30 (15.5%) 37 (19.2%)
1.01 (0.98 – 1.05) 13.09 (3.03 – 56.56) 3.96 (1.67 – 9.38) 0.53 (0.20 – 1.36) 3.70 (1.04 – 13.09) 1.01 (0.97 – 1.03) 2.41 (1.05 – 5.53) 2.86 (1.21 – 6.75) 0.88 (0.31 – 2.46)
0.491 <0.001 0.002 0.257 0.110∗ 0.151 0.058 0.027 1.000
SBP = systolic blood pressure, HR = heart rate, Hb = haemoglobin Bold indicates a significant finding. † Analysed as a continuous variable. ∗ Indicates that Fisher’s Exact Test was applied using double the one-tailed exact probability.
who had solitary renal injuries died. The cause of death was attributable to polytrauma and severe accompanying injuries in all cases of patients who died. Discussion The incidence of TRI of 1.5 per 10 0,0 0 0 population per year, is lower than the incidence of 4.89 per 10 0,0 0 0 population per year reported from the USA [11]. TRI accounted for 1.7% of all trauma cases in our series, which is in keeping with the reported range of 0.3% to 3.25%. TRI most commonly afflicts young men between 20 and 39 years of age [12, 13]. Our data reflects the high incidence of interpersonal and intentional trauma in South Africa [14] with an almost equal distribution of blunt and penetrating trauma. This is contrary to findings in the developed world where blunt injury predominates [13]. Patients with pre-existing renal anatomical abnormalities are predisposed to TRI following relatively minor trauma [15]. Over the last five decades, there has been a move towards NOM of TRI. This was initially applied mostly to blunt low-grade injuries and NOM is now the standard of care for AAST grade I and II injuries [6]. This is reflected in our data. NOM has been successfully extended to higher grades of injury and penetrating injuries [6]. This too is reflected in our data. Despite successful non-operative management in high-grade and penetrating injuries, both remain risk factors for nephrectomy. In the present study, the nephrectomy rate for high-grade injuries was 20.6% compared with 1% for lowgrade injuries and was 19% for penetrating injuries compared with 6% for blunt injuries. A recent report from North America [6] on 431 adult patients with high grade renal injuries documented 236 (55%) grade III, 142 (33%) grade IV, and 53 (12%) grade V injuries. In this cohort 55/431 patients (12%) ultimately required nephrectomy, and of these, 33 (60%) were penetrating injuries. Nephrectomy rates were 15% and 62% for grade IV and V injuries respectively, and 27% for penetrating injuries. In our series, 27 patients (12%) underwent initial nephrectomy for all grades of injury. For grade IV and grade V injuries, our nephrectomy rates were 23% and 32% respectively. The incidence of penetrating trauma in our series was much higher (44%) than in the US (29%) and this may account for some of these differences, as the reported nephrectomy rate for penetrating renal trauma is in the order of 20% [16]. In our study, eight patients (3.6%) underwent renorrhaphy which is lower than the 5% renorrhaphy and partial nephrectomy rate reported in the US study. In a stable patient with blunt abdominal trauma, abdominal CT scan allows for accurate grading of TRI and planning of a nonoperative strategy. This is associated with excellent rates of renal salvage even in the presence of high-grade injuries. In a patient with penetrating abdominal trauma and without an indication for urgent laparotomy selective imaging allows for NOM with
good rates of renal salvage. In an unstable patient who is expedited to the OR, TRI presents as a lateral retro-peritoneal hematoma at laparotomy. Previously, such haematomas were explored in all cases of penetrating trauma and only selectively in cases of blunt trauma. Our current data suggests that even in penetrating trauma, selective exploration is acceptable. Once NOM has been decided on, the rate of failure is low with 1.1% of patients failing initial management and requiring nephrectomy. This compares favorably with the reported failure rate of NOM of 2.7–5.4% [11]. Urological sepsis and bleeding are the most common causes of failed NOM and endourological and endovascular techniques such as ureteral stenting and embolization have contributed to reducing the nephrectomy rate. In the present study, embolization was only utilized in 0.9% of patients and ureteral stenting in 1.8% of patients. Conclusion Even in high-grade injuries and penetrating trauma, the majority of patients with TRI can be managed non-operatively or with the assistance of endourological or endovascular techniques, with good outcomes. Perinephric haematomas discovered at laparotomy can be safely managed expectantly regardless of whether the mechanism is penetrating or blunt. Risk factors for nephrectomy include the presence of high- grade injuries, penetrating trauma and metabolic acidosis on presentation. Declaration of Competing Interest None. References [1] Msemburi W, Pillay-van Wyk V, Dorrington RE, Neethling I, Nannan N, Groenewald P, et al.. Second national burden of disease study for south africa: cause-of-death profile for south africa. Cape Town: South African Medical Research Council; 2016. p. 1997–2012. ISBN: 978-1-928340-06-5. [2] Shewakramani S, Reed K. Genitourinary trauma. Emerg Med Clin North Am 2011;29(3):501–18. doi:10.1016/j.emc.2011.04.009. [3] Santucci RA, Bartley JM. Urologic trauma guidelines: a 21st century update. Nat Rev Urol 2010;7(9):510–19. doi:10.1038/nrurol.2010.119. [4] Anselmo da Costa I, Amend B, Stenzl A, Bedke J. Contemporary management of acute kidney trauma. J Acute Dis 2016;5(1):29–36. doi:10.1016/j.joad.2015. 08.003. [5] Moore EE, Shackford SR, Pachter HL, McAninch JW, Browner BD, Champion HR, et al. Organ injury scaling: spleen, liver, and kidney. J Trauma 1989;29(12):1664–6. [6] Keihani S, Xu Y, Presson AP, Hotaling JM, Nirula R, Piotrowski J, et al. Contemporary management of high-grade renal trauma: results from the american association for the surgery of trauma genitourinary trauma study. J Trauma Acute Care Surg 2018;84(3):418–25. doi:10.1097/TA.0 0 0 0 0 0 0 0 0 0 0 01796. [7] Laing G, Bruce J, Aldous C, Clarke D. The design, construction and implementation of a computerised trauma registry in a developing south african metropolitan trauma service. Injury 2014;45(1):3–8. doi:10.1016/j.injury.2013. 05.013.
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Contents lists available at ScienceDirect
Injury journal homepage: www.elsevier.com/locate/injury
Traumatic renal injury: Five-year experience at a major trauma centre in South Africa M.S. Salem a, R.J. Urry b,∗, V.Y. Kong c,d, D.L. Clarke c,d, J. Bruce d, G.L. Laing d a
Department of Urology, University of KwaZulu-Natal, Durban, South Africa Department of Urology, Sefako Makgatho Health Sciences University, Ga-Rankuwa, South Africa c Department of Surgery, University of the Witwatersrand, Johannesburg, South Africa d Department of Surgery, University of KwaZulu-Natal, Durban, South Africa b
a r t i c l e
i n f o
Article history: Accepted 14 October 2019 Available online xxx Keywords: Renal trauma Kidney trauma Abdominal trauma Blunt trauma Penetrating trauma Traumatic renal injury
a b s t r a c t Background: This study is intended to assess the current optimal management of traumatic renal injuries (TRIs), with a focus on high-grade and penetrating injuries. Methods: The Pietermaritzburg Metropolitan Trauma Service registry was interrogated retrospectively for patients managed for TRI between 1 January 2012 and 31 December 2016. Results: Of 13,315 inured patients treated by the PMTS, 223 (1.7%) had TRIs with an incidence of 1.5 per 10 0,0 0 0 population per year. The majority were males between 20 and 39 years of age. The distribution of mechanism of injury was 56.1% (n = 125) blunt and 43.9% (n = 98) penetrating trauma with no association between mechanism and grade of injury. Penetrating trauma was associated with hollow viscus and diaphragm injuries and blunt trauma with solid organ injuries. A total of 118 patients (52.9%) were managed non-operatively, 60 (26.9%) were not explored at operation, 27 (12.1%) underwent initial nephrectomy and 8 (3.6%) underwent renorraphy. Low-grade injuries (AAST I and II) and highgrade injuries (AAST III-V) were managed without renal intervention (non-operatively or not explored at laparotomy for associated injuries) in 88.7% (n = 87) and 72.0% (n = 91) of cases respectively. Blunt and penetrating injuries were managed without renal intervention in 87.9% (n = 109) and 70% (n = 69) of cases respectively. The initial nephrectomy rate was 1% (n = 1) and 20.6% (n = 26) for low- and high-grade injuries respectively, and 6.5% (n = 8) and 19% (n = 19) for blunt and penetrating injuries respectively. High grade (AAST III-V) injury (OR 14.94; 95% CI 3.36 – 66.34; p<0.001), penetrating mechanism (OR 4.99; 95% CI 1.98 – 12.52; p = 0.001) and metabolic acidosis (OR 2.73; 95% CI 1.04 – 7.20; p = 0.042) were significant risk factors for nephrectomy. Four patients (1.8%) underwent ureteral stent insertion and 2 (0.9%) underwent embolisation. The failure rate of initial non-operative management was 1.1%. The mortality rate was 8.1% (n = 18), but no patients with solitary renal injuries died. Conclusion: Even in high-grade injuries and penetrating trauma, the majority of patients with TRI can be managed non-operatively or with the assistance of endourological or endovascular techniques, with good outcomes. Risk factors for nephrectomy include the presence of high-grade injuries, penetrating trauma and metabolic acidosis on presentation. © 2019 Elsevier Ltd. All rights reserved.
Introduction Injury remains a significant problem in South Africa with urogenital injuries occurring in approximately 10% of trauma patients and TRIs occurring in 1–5% of trauma patients [1,2,3,4]. South African surgeons have acquired a large and sustained experience in the management of trauma, and the development of electronic databases in trauma centres such as ours over the last decade, has ∗ Corresponding author. Suite 211, South Block, Netcare Waterfall City Hospital, Midrand, Johannesburg, South Africa, 1682. E-mail address: [email protected] (R.J. Urry).
facilitated the documentation of this experience. Globally, over the last half century, there has been a move towards surgical minimalism and non-operative management (NOM) in trauma and these non-operative approaches have been applied successfully to traumatic renal injuries (TRIs). Increasing experience and success with NOM has resulted in it being applied to higher grades of TRI. Currently, NOM of low-grade, blunt TRI is widely accepted as the standard of care. However, NOM for high-grade TRI and penetrating injuries is less well defined. In light of these developments and controversies, this study set out to review our experience with TRI, define the spectrum and outcome of TRI in our setting, and interrogate the role of NOM in the management of these injuries. A
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Please cite this article as: M.S. Salem, R.J. Urry and V.Y. Kong et al., Traumatic renal injury: Five-year experience at a major trauma centre in South Africa, Injury, https://doi.org/10.1016/j.injury.2019.10.034
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particular focus was placed on high-grade TRIs and penetrating injuries in order to clarify the role and indications for NOM in these more severe and destructive renal injuries. It is hoped that this data will refine management strategies for TRI.
Methods Management of TRI The Pietermaritzburg Metropolitan Trauma Service (PMTS) is a tertiary level major trauma centre located in Pietermaritzburg, the capital city of the KwaZulu-Natal (KZN) province of South Africa. The service covers 19 district hospitals in KZN with a catchment population of approximately 3 million people. TRI is managed primarily by trauma surgeons whilst more complex injuries requiring more specialized urological intervention are managed in conjunction with the Urology service. Patients are managed according to standard trauma protocols: •
•
•
•
•
All patients with abdominal trauma, blunt or penetrating, are resuscitated. Non-responders as well as patients with penetrating injuries who are peritonitic are expedited to the operating room (OR). The remainder undergo an abdominal CT scan and all injuries are graded according to the American Association for the Surgery of Trauma (AAST) grading system [5]. Patients with blunt TRI who continue to respond to resuscitation and who do not have a completely devascularised kidney are treated with NOM. The grade of the injury is not in itself an indication for surgery. These patients are re-imaged selectively. If there is ongoing haemtauria or a urinary leak, they are managed by angiographic embolisation or endourological drainage. Patients with penetrating abdominal trauma are managed according to a selective approach. Patients who do not have an indication for urgent operative management are admitted and observed. At laparotomy, perinephric haematomas are not routinely explored unless there is compelling evidence that there is active bleeding (for example, an expanding lateral retroperitoneal haematoma). In the event of exploration, attempts may be made to repair the TRI if it is low grade and the patient is stable. However, if the injury is high-grade (AAST III-V) or if the patient’s physiology is compromised, nephrectomy is generally performed. The protocol for NOM includes admission, bed-rest, regular monitoring of vital signs, regular physical abdominal examination, and regular haemoglobin and haematocrit assessment [6].
Data collection The PMTS prospectively collects data for the purpose of research and auditing using a prospective hybrid electronic medical registry (HEMR) [7]. In terms of the urogenital system, traumatic bladder injuries [8] and combined colon and renal injuries [9] have already been described using this registry. The registry was interrogated retrospectively, and all patients diagnosed with a TRI between January 2012 and December 2016 were identified. Demographic data, mechanism of injury, grade of injury, accompanying injuries, management and outcome were assessed. Mechanism of injury was classified into blunt, including road traffic accidents (RTAs), pedestrian vehicle accidents (PVAs), assaults, falls and other causes; and penetrating, including stab wounds (SWs), gunshot wounds (GSWs) and other causes. Ethics approval for the study was granted by the Biomedical Research Ethics Committee (BREC) of the University of KwaZulu-Natal (BE642/16 and BCA221/13).
Fig. 1. Age distribution of patients with TRI.
Statistical analysis Statistical analyses were performed using the Statistical Package for Social Sciences (SPSS) version 24 (IBM, USA). The incidence of TRI was calculated in terms of the number of injuries per 10 0,0 0 0 population per year. Comparison of means was performed using the t-test for equality of means in independent samples. Pearson’s χ 2 test with Yates’ correction for continuity [10] was used to compare categorical variables. If the projected frequency, assuming a true null hypothesis, in a cell of a two-by-two table was less than five observations, Fisher’s exact test was applied using double the one-tailed exact probability [10]. Univariable logistic regressions were performed to determine the odds ratio for risk factors for nephrectomy. Each significant finding was checked using Pearson’s χ 2 test with Yates’ correction for continuity and the corrected significance reported. Significant risk factors were further analysed using a multivariable regression, with each variable entered into the model simultaneously (i.e. non-stepwise), and variables with a significant impact on the odds ratio of the dependant variable identified as risk factors. A p-value <0.05 (5%) was considered statistically significant. Results During the period under review, 13,315 injured patients were admitted by the PMTS. Of these, 348 patients (2.6%) had urological injuries. There were 223 renal injuries, accounting for 64.1% of urological injuries and 1.7% of all trauma cases. The kidney was the commonest urological organ injured, followed by the bladder (27.0%; n = 94), urethra (5.4%; n = 19) and ureters (3.4%, n = 12). The incidence of injury requiring hospital treatment was 88.8 per 10 0,0 0 0 population per year, and of TRI 1.5 per 10 0,0 0 0 population per year. Demographic data The mean age of patients with TRI was 27 years (SD 11.4 years; range 2–69 years). Thirty-five patients (15.7%) were under the age of 18 years. The majority (n = 181; 81.2%) were male and between the ages of 20 and 39 years. Fig. 1 demonstrates the age distribution of patients with TRI. Mechanism of injury The mechanism of injury is illustrated in Fig. 2. The blunt injuries not classified included those caused by animals, structural collapse, falling trees and falls from tractors. Of the patients younger than 18 years of age, 89% (n = 31) sustained blunt trauma with falls and PVAs the commonest cause and 11% (n = 4) sus-
Please cite this article as: M.S. Salem, R.J. Urry and V.Y. Kong et al., Traumatic renal injury: Five-year experience at a major trauma centre in South Africa, Injury, https://doi.org/10.1016/j.injury.2019.10.034
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Total Traumac Renal Injuries n=223
Blunt trauma n=125 (56.1%)
Penetrang trauma n=98 (43.9%)
Other Falls 4.8% 12.8% RTAs 43.2%
Assualts 10.4%
GSWs 48.0%
SWs 52.0%
PVAs 28.8% Fig. 2. Summary of the mechanism and causes of TRIs.
30.0 25.0 10.3
20.0 15.0
7.2
13.0
Penetrang (%) 15.2
10.0
8.5
13.0 10.3
5.0
4.9
8.5
9.0
Grade IV
Grade V
Blunt (%)
0.0 Grade I
Grade II
Grade III
Fig. 3. Distribution of TRI by mechanism and AAST grade.
tained penetrating trauma. Patients younger than 18 years were significantly less likely to sustain penetrating trauma (p<0.001). Diagnosis Diagnosis of TRI was made by multiphase abdominal computed tomography (CT) scan with intravenous contrast in stable patients (n = 188; 84.3%) and intra-operatively in unstable patients who were taken directly from the emergency room to the operating room (n = 35; 15.7%). Laterality and grade of injury The left kidney was injured in 51.8% (n = 87), the right kidney in 44.6% (n = 75) and both kidneys in 3.6% (n = 6) of cases. The six patients with bilateral injuries all suffered blunt trauma and were either involved in RTAs or PVAs. The grade of renal injury, according to the AAST kidney injury scale is illustrated in Fig. 3. There
was no significant association between mechanism and high-grade TRI (p = 0.598). Associated injuries The frequency of associated injuries compared by mechanism is summarized in table 1. Isolated renal injury occurred in 70 cases (31.5%) and was not significantly associated with either penetrating or blunt trauma (p = 0.485). Accompanying hollow viscus injuries (stomach, small intestine and colon) as well as diaphragm injuries were significantly associated with penetrating trauma. Accompanying solid organ injuries, particularly liver, spleen and adrenal injuries, were significantly associated with blunt trauma. Injury to other urogenital organs were not likely to accompany TRI. Management Most TRIs were initially managed non-operatively. They were either subjected to NOM primarily (n = 118; 53.2%) or were not
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In one patient, the AAST grade of injury could not be determined and this patient was not included in the analysis. †
Total
Penetrating Blunt
98 79.0% 0 0.0% 8 6.5% 3 2.4% 1 0.8% 11 8.9% 3 2.4% 124 100.0% 3 27.3% 0 0.0% 5 45.5% 0 0.0% 0 0.0% 3 27.3% 0 0.0% 11 100.0%
Penetrating Blunt
14 70.0% 0 0.0% 5 25.0% 0 0.0% 0 0.0% 1 5.0% 0 0.0% 20 100.0% 8 42.1% 0 0.0% 7 36.8% 0 0.0% 1 5.3% 3 15.8% 0 0.0% 19 100.0%
Penetrating Blunt
15 78.9% 0 0.0% 2 10.5% 1 5.3% 1 5.3% 0 0.0% 0 0.0% 19 100.0% 3 13.0% 3 13.0% 6 26.1% 1 4.3% 0 0.0% 10 43.5% 0 0.0% 23 100.0%
Penetrating Blunt
29 85.3% 0 0.0% 1 2.9% 1 2.9% 0 0.0% 2 5.9% 1 2.9% 34 100.0% 4 13.8% 4 13.8% 0 0.0% 0 0.0% 0 0.0% 21 72.4% 0 0.0% 29 100.0% Abdominal operation but no renal exploration Unknown
The mortality rate of patients with TRI was 8.1% (n = 18). Of patients with low grade injuries, 3.1% (n = 3) died and of patients with high grade injuries, 11% (n = 14) died (p = 0.048). No patients
Embolisation of kidney
Outcomes
Insertion of JJ stent
In four patients (1.8%) a JJ-stent was inserted as a separate procedure and 2 patients (0.9%) were referred to interventional radiology for embolisation of a bleeding kidney.
Surgical exploration and repair of kidney Nephrectomy
Need for additional procedures
Penetrating
Twenty-seven patients (12.2%) underwent initial nephrectomy. High grade injuries (p<0.001) and penetrating injuries (p = 0.002) were significantly associated with nephrectomy. The highest initial nephrectomy rates were seen in grades III, IV and V penetrating injuries (26.1%, 36.8% and 45.5% respectively). The initial nephrectomy rate was 1% (n = 1 of 96) and 20.6% (n = 26 of 126) for low- and high-grade injuries respectively, and 6.5% (n = 8) and 19% (n = 19) for blunt and penetrating injuries respectively. Two patients (1.1% of all patients and 2.9% of patients with penetrating injuries, not subjected to nephrectomy) underwent delayed nephrectomy. Analysis of risk factors for nephrectomy (initial and delayed) is summarized in table 3. On multivariable regression analysis, high grade (AAST III-V) injury (OR 14.94; 95% CI 3.36 – 66.34; p<0.001), penetrating mechanism (OR 4.99; 95% CI 1.98 – 12.52; p = 0.001) and base deficit greater than 6 (OR 2.73; 95% CI 1.04 – 7.20; p = 0.042) were significant risk factors for nephrectomy.
16 69.6% 0 0.0% 0 0.0% 1 4.3% 0 0.0% 5 21.7% 1 4.3% 23 100.0%
Nephrectomy
Blunt
explored at the time of laparotomy for other associated injuries (n = 60; 27.0%). Eight patients (3.6%) underwent renorraphy, all with penetrating injuries, and 27 (12.2%) underwent nephrectomy. The initial management according to AAST kidney injury scale and mechanism of injury is presented in table 2. Low-grade injuries (AAST I and II) and high-grade injuries (AAST III-V) were managed without renal intervention (non-operatively or not explored at laparotomy for associated injuries) in 91% (87/96) and 72.2% (91/126) of cases respectively. Blunt and penetrating injuries were managed without renal intervention in 87.9% (109/124) and 70% (69/98) of cases respectively. Intervention was significantly associated with high grade injuries (p<0.001) and penetrating injuries (p<0.001).
2 12.5% 1 6.3% 1 6.3% 0 0.0% 0 0.0% 12 75.0% 0 0.0% 16 100.0%
Bold indicates a significant finding. ∗ Indicates that Fisher’s Exact Test was applied using double the onetailed exact probability. † The column count may exceed the total as some patients had multiple injuries.
Penetrating
0.001 0.025 0.877 0.048∗ 0.001 0.684∗ 0.002 <0.001 – 1.000∗ 0.808∗ <0.001 0.388∗
Blunt
22 (22%) 17 (17%) 8 (8%) 1 (1%) 14 (14%) 6 (6%) 13 (13%) 33 (34%) 0 (0%) 0 (0%) 1 (1%) 16 (16%) 2 (2%)
Total†
55 (44.4%) 39 (31.5%) 12 (9.7%) 9 (7.3%) 2 (1.6%) 5 (4.0%) 2 (1.6%) 4 (3.2%) 0 (0%) 1 (0.8%) 3 (2.4%) 2 (1.6%) 0 (0%)
AAST V
77 (34.7%) 56 (25.2%) 20 (9.0%) 10 (4.5%) 16 (7.2%) 11 (5.0%) 15 (6.8%) 37 (16.7%) 0 (0%) 1 (0.5%) 4 (1.8%) 18 (8.1%) 2 (0.9%)
AAST IV
p-Value
Liver Spleen Pancreas Adrenal Stomach Duodenum Small Intestine Colon Rectum Ureter Bladder Diaphragm IVC
AAST III
Penetrating (n = 98)
AAST II
Blunt (n = 125)
AAST I
Total (n = 223)†
Table 2 Initial management of TRI classified by AAST kidney injury scale and mechanism, showing number and percentage management within each grade and mechanism.
Organ
24 85.7% 0 0.0% 0 0.0% 0 0.0% 0 0.0% 3 10.7% 1 3.6% 28 100.0%
Table 1 Frequency of accompanying injuries and comparison by mechanism.
20 20.4% 8 8.2% 19 19.4% 1 1.0% 1 1.0% 49 50.0% 0 0.0% 98 100.0%
M.S. Salem, R.J. Urry and V.Y. Kong et al. / Injury xxx (xxxx) xxx
Non-operative
4
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Table 3 Results of univariate logistic regression to identify risk factors for nephrectomy (initial and delayed).
Parameter
Nephrectomy patients (n = 29)
No-nephrectomy patients (n = 193)
OR (95% CI)
p-Value
Age in years† High grade (AAST III-V) injury Penetrating mechanism Accompanying injuries SBP <90 mmHg on presentation HR on presentation† Hb < 10 g/dL on presentation Base deficit < 6 Lactate > 4 mmol/L
– 27 (93%) 21 (72%) 6 (21%) 4 (13%) – 11 (38%) 10 (35%) 5 (17%)
– 98 (50.8%) 77 (39.9%) 64 (33.2%) 8 (4.1%) – 39 (20.2%) 30 (15.5%) 37 (19.2%)
1.01 (0.98 – 1.05) 13.09 (3.03 – 56.56) 3.96 (1.67 – 9.38) 0.53 (0.20 – 1.36) 3.70 (1.04 – 13.09) 1.01 (0.97 – 1.03) 2.41 (1.05 – 5.53) 2.86 (1.21 – 6.75) 0.88 (0.31 – 2.46)
0.491 <0.001 0.002 0.257 0.110∗ 0.151 0.058 0.027 1.000
SBP = systolic blood pressure, HR = heart rate, Hb = haemoglobin Bold indicates a significant finding. † Analysed as a continuous variable. ∗ Indicates that Fisher’s Exact Test was applied using double the one-tailed exact probability.
who had solitary renal injuries died. The cause of death was attributable to polytrauma and severe accompanying injuries in all cases of patients who died. Discussion The incidence of TRI of 1.5 per 10 0,0 0 0 population per year, is lower than the incidence of 4.89 per 10 0,0 0 0 population per year reported from the USA [11]. TRI accounted for 1.7% of all trauma cases in our series, which is in keeping with the reported range of 0.3% to 3.25%. TRI most commonly afflicts young men between 20 and 39 years of age [12, 13]. Our data reflects the high incidence of interpersonal and intentional trauma in South Africa [14] with an almost equal distribution of blunt and penetrating trauma. This is contrary to findings in the developed world where blunt injury predominates [13]. Patients with pre-existing renal anatomical abnormalities are predisposed to TRI following relatively minor trauma [15]. Over the last five decades, there has been a move towards NOM of TRI. This was initially applied mostly to blunt low-grade injuries and NOM is now the standard of care for AAST grade I and II injuries [6]. This is reflected in our data. NOM has been successfully extended to higher grades of injury and penetrating injuries [6]. This too is reflected in our data. Despite successful non-operative management in high-grade and penetrating injuries, both remain risk factors for nephrectomy. In the present study, the nephrectomy rate for high-grade injuries was 20.6% compared with 1% for lowgrade injuries and was 19% for penetrating injuries compared with 6% for blunt injuries. A recent report from North America [6] on 431 adult patients with high grade renal injuries documented 236 (55%) grade III, 142 (33%) grade IV, and 53 (12%) grade V injuries. In this cohort 55/431 patients (12%) ultimately required nephrectomy, and of these, 33 (60%) were penetrating injuries. Nephrectomy rates were 15% and 62% for grade IV and V injuries respectively, and 27% for penetrating injuries. In our series, 27 patients (12%) underwent initial nephrectomy for all grades of injury. For grade IV and grade V injuries, our nephrectomy rates were 23% and 32% respectively. The incidence of penetrating trauma in our series was much higher (44%) than in the US (29%) and this may account for some of these differences, as the reported nephrectomy rate for penetrating renal trauma is in the order of 20% [16]. In our study, eight patients (3.6%) underwent renorrhaphy which is lower than the 5% renorrhaphy and partial nephrectomy rate reported in the US study. In a stable patient with blunt abdominal trauma, abdominal CT scan allows for accurate grading of TRI and planning of a nonoperative strategy. This is associated with excellent rates of renal salvage even in the presence of high-grade injuries. In a patient with penetrating abdominal trauma and without an indication for urgent laparotomy selective imaging allows for NOM with
good rates of renal salvage. In an unstable patient who is expedited to the OR, TRI presents as a lateral retro-peritoneal hematoma at laparotomy. Previously, such haematomas were explored in all cases of penetrating trauma and only selectively in cases of blunt trauma. Our current data suggests that even in penetrating trauma, selective exploration is acceptable. Once NOM has been decided on, the rate of failure is low with 1.1% of patients failing initial management and requiring nephrectomy. This compares favorably with the reported failure rate of NOM of 2.7–5.4% [11]. Urological sepsis and bleeding are the most common causes of failed NOM and endourological and endovascular techniques such as ureteral stenting and embolization have contributed to reducing the nephrectomy rate. In the present study, embolization was only utilized in 0.9% of patients and ureteral stenting in 1.8% of patients. Conclusion Even in high-grade injuries and penetrating trauma, the majority of patients with TRI can be managed non-operatively or with the assistance of endourological or endovascular techniques, with good outcomes. Perinephric haematomas discovered at laparotomy can be safely managed expectantly regardless of whether the mechanism is penetrating or blunt. Risk factors for nephrectomy include the presence of high- grade injuries, penetrating trauma and metabolic acidosis on presentation. Declaration of Competing Interest None. References [1] Msemburi W, Pillay-van Wyk V, Dorrington RE, Neethling I, Nannan N, Groenewald P, et al.. Second national burden of disease study for south africa: cause-of-death profile for south africa. Cape Town: South African Medical Research Council; 2016. p. 1997–2012. ISBN: 978-1-928340-06-5. [2] Shewakramani S, Reed K. Genitourinary trauma. Emerg Med Clin North Am 2011;29(3):501–18. doi:10.1016/j.emc.2011.04.009. [3] Santucci RA, Bartley JM. Urologic trauma guidelines: a 21st century update. Nat Rev Urol 2010;7(9):510–19. doi:10.1038/nrurol.2010.119. [4] Anselmo da Costa I, Amend B, Stenzl A, Bedke J. Contemporary management of acute kidney trauma. J Acute Dis 2016;5(1):29–36. doi:10.1016/j.joad.2015. 08.003. [5] Moore EE, Shackford SR, Pachter HL, McAninch JW, Browner BD, Champion HR, et al. Organ injury scaling: spleen, liver, and kidney. J Trauma 1989;29(12):1664–6. [6] Keihani S, Xu Y, Presson AP, Hotaling JM, Nirula R, Piotrowski J, et al. Contemporary management of high-grade renal trauma: results from the american association for the surgery of trauma genitourinary trauma study. J Trauma Acute Care Surg 2018;84(3):418–25. doi:10.1097/TA.0 0 0 0 0 0 0 0 0 0 0 01796. [7] Laing G, Bruce J, Aldous C, Clarke D. The design, construction and implementation of a computerised trauma registry in a developing south african metropolitan trauma service. Injury 2014;45(1):3–8. doi:10.1016/j.injury.2013. 05.013.
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