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Evaluation of a 15-year experience with splenic injuries in a state trauma system
Evaluation of a 15-year experience with splenic injuries in a state trauma system Brian G. Harbrecht, MD, Mazen S. Zenati, MD, MPH, Juan B. Ochoa, MD, Juan C. Puyana, MD, Louis H. Alarcon, MD, and Andrew B. Peitzman, MD, Pittsburgh, Pa
Background. The management of splenic injuries has evolved with a greater emphasis on nonoperative management. Although several institutions have demonstrated that nonoperative management of splenic injuries can be performed with an increasing degree of success, the impact of this treatment shift on outcome for all patients with splenic injuries remains unknown. We hypothesized that outcomes for patients with splenic injuries have improved as the paradigm for splenic injury treatment has shifted. Methods. Consecutive patients from 1987 to 2001 with splenic injuries who were entered into a state trauma registry were reviewed. Demographic variables, injury characteristics, and outcome data were collected. Results. The number of patients who were diagnosed with splenic injuries increased from 1987 through 2001, despite a stable number of institutions submitting data to the registry. The number of minor injuries and severe splenic injuries remained stable, and the number of moderately severe injuries significantly increased over time. Overall mortality rate improved but primarily reflected the decreased mortality rates of moderately severe injuries; the mortality rate for severe splenic injuries was unchanged. Conclusion. Trauma centers are seeing increasing numbers of splenic injuries that are less severe in magnitude, although the number of the most severe splenic injuries is stable. The increased proportion of patients with less severe splenic injuries who are being admitted to trauma centers is a significant factor in the increased use and success rate of nonoperative management. (Surgery 2007;141:229-38.) From the Department of Surgery, University of Pittsburgh, Pittsburgh, Pa
Treatment of the injured patient with a splenic injury over the last several decades has evolved from mandatory surgical exploration and splenectomy for even minor injuries to an emphasis on splenic preservation and a primary role for nonoperative treatment for most patients.1,2 Several large studies on the management of splenic injuries have focused on describing the shift from operative to nonoperative management3-5 or examining specific differences in resource use between trauma centers.6,7 While these changes in the management of splenic injuries have occurred, there has also been Presented in poster format at the 62nd Annual Meeting of the American Association for the Surgery of Trauma, Sept. 11-13, 2003, Minneapolis, MN. Accepted for publication June 30, 2006. Reprint requests: Brian G. Harbrecht, MD, Associate Professor of Surgery, University of Pittsburgh Medical Center, F1264-200 Lothrop St, Pittsburgh, PA 15213. 0039-6060/$ - see front matter © 2007 Mosby, Inc. All rights reserved. doi:10.1016/j.surg.2006.06.032
an increased emphasis on the delivery of organized trauma care, the development of local and regional trauma systems, and the transport of severely injured patients to centers with particular interest and expertise in the care of trauma patients.8-12 The concentration of trauma patients into institutions with specific interest in the care of the injured has helped to promote the evolution in splenic injury management. Several authors have suggested that nonoperative management of splenic injuries has been overemphasized and that morbidity has occurred after attempts to manage inappropriately some splenic injuries nonoperatively.13-15 It is clear, however, that nonoperative treatment has become the most common method of splenic salvage in injured patients.6-8 A number of reports have demonstrated that splenic injuries can be managed nonoperatively with increasing degrees of success.16-20 Intuitively, one would predict that decreasing the frequency of operations would decrease the frequency of postoperative complications and death. The increased emphasis on nonoperative management with hepatic injuries is thought to be the SURGERY 229
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primary factor responsible for the declining mortality rate that has been associated with these injuries over the last several decades.14 The impact of the shift towards nonoperative treatment on outcome for patients with splenic injuries, however, has not been studied thoroughly. The state trauma system in Pennsylvania has been in existence for much of the period in which changes in the diagnosis and management of splenic injuries have evolved and has collected data on injured patients for ⬎15 years. We hypothesized that the mortality rate for patients with splenic injuries who were treated in the state’s trauma centers has decreased. We also sought to determine factors that could contribute to outcome differences over time. MATERIAL AND METHODS The Pennsylvania Trauma Outcome Study (PTOS) is the database that is maintained by the Pennsylvania Trauma Systems Foundation (PTSF) and includes data contributed by all accredited trauma centers in the state.21,22 Briefly, adult and pediatric trauma centers submit data on all patients with a length of stay of ⬎48 hours, injured patients who die, and all admissions to the intensive care unit (ICU).21,22 Patients with splenic injuries were identified by International Classification of Diseases– 9-Clinical Modification (ICD-9-CM) codes (865.XX) from the start of data entry in October of 1986 through 2001. Because data for calendar year 1986 were incomplete, patients from 1986 were excluded, and the analysis was performed on data for patients who were admitted from 1987 to 2001. Demographic information, mechanism of injury, vital signs on admission, procedures performed, and outcome data were collected. The listed E codes were used to identify the mechanism of injury and patients were listed as either motor vehicle crash (MVC; codes xxx.0, xxx.1, xxx.4, xxx.8, xxx.9 for E810-E819; E958.5; and E988.5), motorcycle crash (codes xxx.2 and xxx.3 for E810-E825), pedestrian struck by vehicle (E810-E825, xxx.7), falls (E880-E888, E957, E958, E987.0, and E987.1), assaults (E960, E967, E968), other blunt injuries (allterrain vehicle crashes, bicycle crashes, and all other blunt E codes), stabs (E870.5, E920, E956, E966, and E986), and gunshot wounds (E922, E955, E965.0E965.4, E968.6, E976.0, E985.0-E985.4). Burn injuries were excluded from the analysis. Surgical procedures were included in the database from 1993 to 2001. Operations on the spleen were classified as either splenectomy or splenic repair (splenorrhaphy). Patients who did not have a splenectomy or splenor-
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rhaphy were categorized as having been treated nonoperatively. Registrars at each trauma center performed data abstraction and submission to the PTOS. The PTSF has established guidelines for trauma center accreditation and creates standards for registrar training, registrar continuing education, and the number of trauma registrars, based on institutional volume. For injury-related data, an anatomic description of the injury was abstracted from the medical record and submitted to the PTOS. The PTOS uses a commercially available software program (Tri-Code; Digital Innovation Inc, Forest Hill, Md) to convert the injury description to ICD-9-CM and Abbreviated Injury Scale (AIS) codes. The database used AIS version 1985 from 1986 to 1993 and AIS-90 from 1993 until 2001. We classified splenic injuries as mild (865.x1), moderate (865.x2 and 865.x3), and severe (865.x4). Patients with multiple codes listed for several discreet injuries to the spleen were classified according to the most severe injury. Data are presented as the mean ⫾ SE. Statistical analysis was performed with StatView software (version 5.0; SAS Institute Inc, Cary, NC). Continuous variables were analyzed by analysis of variance and the Tukey-Kramer post hoc test. Categoric variables were analyzed by chi-square and the Fisher’s exact test. A probability value of ⬍.05 was considered statistically significant. RESULTS There were 11,609 patients with splenic injuries whose data were entered into the PTOS database from 1986 through 2001. There were 60 patients whose data were entered in 1986 and 4 patients with burn injury who were excluded. Of the 11,545 patients who remained, 10,652 patients had blunt injury and 893 patients had penetrating injury. The total number of patients whose data were entered into the database per year from all trauma centers increased over the 15-year study interval (Fig 1). The percentage of patients who were diagnosed with splenic injuries increased from 3% of PTOS patients in 1987 to 4.3% in 2001 (Fig 1). Thus, the diagnosis of splenic injury was being made more frequently in patients whose data were entered into the PTOS database. The number of patients who were admitted per year with blunt and penetrating splenic injuries over this interval is shown in Fig 2. The number of patients who were admitted to trauma centers with blunt splenic injuries increased over time; the number of patients who were admitted with penetrating splenic injuries peaked in the early 1990s and then decreased (P ⬍ .001). The increased number of patients with
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Fig 1. Percentage of patients with splenic injuries. The total number of patients whose data were entered into the PTOS database () and the percentage of all patients who were diagnosed with splenic injuries (□) on a yearly basis is shown.
Fig 2. Total number of patients with blunt and penetrating injuries to the spleen over the 15-year study interval.
splenic injuries over time could not be attributed simply to increasing numbers of trauma centers within the state because the number of hospitals designated as trauma centers did not fluctuate significantly over time (Table I). When we examined the demographics of all patients with splenic injuries, there was no difference over time in age, gender, ICU length of stay, or pulse rate measured in the Emergency Department (ED; data not shown). Statistically significant increases in ED systolic blood pressure and significant decreases in injury severity score (ISS) and hospital length of stay were observed (Table I). Overall mortality rate also decreased in a statistically significant manner from 25.6% in 1987 to 13.5% in 2001 (Table I; P ⬍ .01 by chi-square test).
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The decline in mortality rate from 1987 to 2001 could be due to improvements in trauma care over the same time period. However, the increase in ED systolic blood pressure and the decrease in ISS suggest that the improved mortality rate could also be due to decreases in overall magnitude of critical illness or severity of injury for patients with splenic injuries. Because the shift towards nonoperative management of splenic injuries has focused primarily on injuries from blunt-force mechanisms, we analyzed blunt and penetrating injuries separately. To evaluate whether differences in spleen injury severity occurred over time, the magnitude of splenic injury was stratified by the ICD-9-CM code (Fig 3). There were a total of 1652 blunt splenic injuries that were classified as severe (ICD-9-CM 865.04), which accounted for 15.4% of all blunt splenic injuries over the 15-year period. The percentage of severe splenic injuries varied from a low of 8.8% of all injuries in 1990 to a high of 19.2% in years 1994 and 1996 but did not change significantly over the 15-year study period. The percentage of minor blunt splenic injuries (ICD-9-CM 865.01) also remained relatively constant throughout this time period (n ⫽ 1309 patients; 12.2% of all blunt injuries; Fig 3). We classified injuries that were listed as 865.02 and 865.03 as moderately severe splenic injuries. There were a total of 2553 splenic injuries that were classified as ICD-9-CM 865.03, which accounted for 23.8% of all blunt splenic injuries, but this diagnosis was recorded less frequently in the later years of study (Fig 3). There was a significant increase over time in the listing of splenic injuries as ICD-9-CM 865.02 (n ⫽ 5194 patients; 48.5% of blunt splenic injuries) that accounted for the substantial increase in total splenic injuries (Fig 3). Thus, the increased frequency of splenic injuries that were being diagnosed in Pennsylvania trauma centers was due to a large increase in less severe, moderate splenic injuries, although the number of severe and minor injuries remained stable over the 15 years of data collection. When we stratified blunt injuries by magnitude of injury, there was no difference over time in age, gender, or ICU length of stay (data not shown) for any magnitude of splenic injury, with the exception that the average age significantly increased in patients with minor splenic injuries (ICD-9-CM 865.01; 27.4 ⫾ 2.3 years in 1987 to 39.2 ⫾ 2.3 years in 2001; P ⬍ .001 by analysis of variance [ANOVA]). There was a statistically significant decrease in the hospital length of stay over time for patients with each magnitude of splenic injury (data not shown). There was also a statistically significant increase in ED systolic blood pressure over the 15-year period for splenic injuries
232 Harbrecht et al
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Table I. Data for all patients with splenic injury Year
Trauma centers (n)
Systolic blood pressure (mm Hg)
Mortality rate (%)
Injury severity score
Hospital length of stay (d)
1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001
23 28 28 24 24 26 26 26 26 26 26 27 27 27 28
100 ⫾ 2 100 ⫾ 2 109 ⫾ 2 108 ⫾ 2 105 ⫾ 2 105 ⫾ 2 110 ⫾ 2*† 112 ⫾ 2*† 111 ⫾ 1*† 113 ⫾ 1*†‡ 115 ⫾ 1*†‡ 117 ⫾ 1*†‡储 117 ⫾ 1*†‡储 116 ⫾ 1*†‡储 118 ⫾ 1*†‡储
25.6 25.8 19.9 20.2 23.3 21.3 15.6 17.6 20.0 15.4 15.9 15.1 14.2 13.0 13.5
28.3 ⫾ 0.8 28.7 ⫾ 0.7 26.4 ⫾ 0.6 27.1 ⫾ 0.6 27.2 ⫾ 0.6 27.2 ⫾ 0.6 27.0 ⫾ 0.7 27.1 ⫾ 0.6 28.1 ⫾ 0.6 27.8 ⫾ 0.6 27.0 ⫾ 0.5 27.1 ⫾ 0.5 25.1 ⫾ 0.5¶ 25.4 ⫾ 0.5** 24.9 ⫾ 0.5¶
14.0 ⫾ 0.9 15.5 ⫾ 1.1 13.8 ⫾ 0.6 14.6 ⫾ 0.8 14.0 ⫾ 1.7 12.9 ⫾ 0.6 13.2 ⫾ 0.6 11.6 ⫾ 0.5† 11.5 ⫾ 0.5† 10.6 ⫾ 0.4†§ 10.5 ⫾ 0.4†§储 10.1 ⫾0.4*†§储 9.5 ⫾ 0.4*†§储# 10.0 ⫾ 0.4*†§储# 9.2 ⫾ 0.4*†§储#
*P ⬍ .05 versus 1987. †P ⬍ .05 versus 1988. ‡P ⬍ .05 versus 1991, 1992. §P ⬍ .05 versus 1991. 储P ⬍ .05 versus 1989, 1990. ¶P ⬍ .05 versus 1987, 1988, 1995, 1996. #P ⬍ .05 versus 1992, 1993. **P ⬍ .05 versus 1988, 1995.
classified as 865.02 (108 ⫾ 5 mm Hg in 1987 vs 120 ⫾ 1 mm Hg in 2001; P ⬍ 05) and 865.03 (95 ⫾ 3 mm Hg in 1987 vs 118 ⫾ 2 mm Hg in 2001; P ⬍ 05), although the ED blood pressure for injuries that were classified as 865.04 was unchanged (99 ⫾ 8 mm Hg in 1987 vs 103 ⫾ 4 mmHg in 2001). There was little change in ISS over time for any magnitude of splenic injury (865.01, 18 ⫾ 2 vs 18 ⫾ 1; 865.02, 24 ⫾ 2 vs 22 ⫾ 1; 865.03, 30 ⫾ 1 vs 28 ⫾ 1; 865.04, 44 ⫾ 2 vs 41 ⫾ 1; 1987 vs 2001, respectively). Blunt injuries were associated with a mortality rate (17.2%) that was significantly less than that of penetrating splenic injuries (24.1%). As expected, the average age of patients who had blunt injury was greater than victims of penetrating splenic injuries (32.5 ⫾ 0.2 years vs 30.6 ⫾ 0.4 years, blunt vs penetrating; P ⫽ .012 by ANOVA). The mortality rate for blunt splenic injuries increased according to the magnitude of the splenic injury (865.01, 10.7%; 865.02, 17.1%; 865.03, 17.7%; 865.04, 21.4%). There was a moderate degree of variation in mortality rates on a yearly basis, but there was no statistically significant difference in mortality rates over time for either severe or minor blunt injuries (Fig 4, A). There was a significant decrease in mortality rates for moderate splenic injuries over time that paralleled the decrease in mortality rates
for the population of patients with splenic injuries as a whole (Fig 4, B). We then evaluated whether the increase in moderate splenic injuries was associated with changes in the injury mechanism. Motor vehicle crashes were the most common mechanism of injury for patients with splenic injuries (Fig 5). The number of patients who were injured in assaults and motorcycle crashes and by being struck by vehicles was relatively constant. Although the total number of patients who had splenic injuries as a consequence of MVC increased over time (Fig 5, A), the yearly percentage of patients with splenic injuries because of MVC decreased. The yearly percentage of patients who were injured in falls and by injuries listed as other (primarily bicycle or all-terrain vehicle crashes) significantly increased over time (P ⫽ .006 by chi-square test; Fig 5, B). There was no significant change in the proportion of patients who had gunshot wounds and stab wounds (data not shown). There were 893 splenic injuries because of penetrating trauma (7.7% of all splenic injuries); most of these injuries (n ⫽ 854; 96%) were minor (865.11). There was no difference in age, ED pulse, or ED systolic blood pressure among patients with penetrating injuries (data not shown). There was a significant decrease in the proportion of women
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Fig 3. Splenic injury severity. The severity of splenic injury was stratified by ICD-9-CM code and plotted over time. A, The total number of patients with splenic injuries (‘) and patients whose injury was listed as ICD9-CM 865.04 (), 865.03 (□), 865.02 (), and 865.01 (Œ) are shown. B, The yearly percentage of all patients with splenic injuries that were listed as ICD-9-CM 865.04 (), 865.03 (□), 865.02 (), and 865.01 (Œ) are shown.
with penetrating splenic injuries, which declined from a high of 20.9% in 1990 to 5.1% in 2001 (P ⬍ .05 by chi-square test). For patients with penetrating splenic injuries (865.11), there was a significant reduction in hospital length of stay (19.3 ⫾ 5.9 days in 1987 vs 14.7 ⫾ 3.0 days in 2001; P ⫽ .039 by ANOVA) but no significant difference in ICU length of stay. Mortality rates averaged 24.1% for penetrating splenic injuries for the duration of this study, and there was no significant difference over time (data not shown). We next examined the methods that had been used to diagnose splenic injuries in this dataset.
Harbrecht et al 233
Fig 4. Mortality rate for patients with blunt splenic injury. A, Mortality rates of patients with severe (865.04, ) and minor (865.01, Œ) blunt splenic injuries is shown. B, The mortality rate for all patients with blunt splenic injuries (‘) and moderate severity injuries (865.03, □, and 865.02, ) is shown.
Diagnostic modalities were listed as computed tomography (CT), surgical procedure (diagnostic peritoneal lavage/laparotomy), or ultrasound. All modalities that were used to diagnose splenic injuries in each patient were recorded so that subjects could have ⬎1 diagnostic test listed. A progressive and statistically significant increase in CT imaging in patients with splenic injuries occurred that is consistent with previous studies.23-25 In 1987, 59.1% of patients with splenic injuries underwent CT scanning as part of their treatment; this increased to 89.4% in 2001 (P ⬍ .0001 by chi-square test). As has been described previously, there was a decrease in the use of diagnostic peritoneal lavage/laparot-
234 Harbrecht et al
Fig 5. Mechanism of injury in patients with splenic injuries. The mechanism of injury was evaluated by E-code and listed as MVC (), motorcycle crash (‘), pedestrian struck by a vehicle (), assault (□), fall (), and other blunt injuries (Œ). The data are presented as (A) the number of patients with each mechanism and (B) the percentage of patients with each mechanism. The decline in MVCs and the increase in fall/other blunt injuries were statistically significant (P ⫽ .0006 by chisquare test).
omy for the diagnosis of splenic injuries (77.9% of patients in 1987 vs 50.5% in 2001; P ⬍ .001). The use of ultrasound in patients with splenic injuries remained relatively steady from 1990 until 1998 when its use increased, which corresponded with the increased interest in ultrasound to diagnose hemoperitoneum (21.9% in 1990 vs 35.0% in 1998 vs 45.7% in 2001).26,27 The shift in treatment of adult splenic injuries toward nonoperative management and the subsequent decrease in operations on the spleen have
Surgery February 2007 been described previously.1-4 Surgical procedures were listed in this database from 1993 to 2001; to verify that our data are similar to previously published experiences, we reviewed trends in management. For patients with penetrating splenic injuries, there was no difference over time in the frequency of operative treatment, and the proportion of splenectomy and splenorrhaphy remained unchanged (data not shown). For blunt injuries, there was a gradual reduction in the total number of patients who had operations on the spleen, a reduction in the frequency of splenorrhaphy, and an increase in the proportion of patients who underwent an operation who received a splenectomy (Fig 6, A). There was a total of 2264 patients who underwent splenectomy for blunt trauma from 1993 to 2001; in these patients, there was no difference over time in age, gender, ED systolic blood pressure, ED pulse, or ICU length of stay (data not shown). There was a statistically significant increase in ISS (30.1 ⫾ 1.0 in 1993; 33.7 ⫾ 1.0 in 2001; P ⫽ .016 by ANOVA) and a statistically significant decrease in hospital length of stay (16.7 ⫾ 1.1 days in 1993; 12.0 ⫾ 0.9 days in 2001; P ⫽ .028). The mortality for patients who underwent splenectomy for blunt trauma was 17.8%, with significant variability from year to year (Table II). There were 311 patients from 1993 to 2001 who had a splenorrhaphy performed for blunt injuries. There was no difference over time in patient age, gender, ED systolic blood pressure, ED pulse, ISS, ICU length of stay, or hospital length of stay (data not shown). The overall mortality rate for patients who underwent splenorrhaphy was 6.1%, with no change over time (Table II). The decrease in splenic surgical procedures over time corresponded to an increase in patients who were treated nonoperatively (Table II).1-4,14-20 The absolute number and the yearly percentage of patients who were treated nonoperatively after blunt injury to the spleen increased significantly, and this shift was associated with a statistically significant decrease in overall mortality rate (Table II). Most nonoperatively treated blunt injuries were moderately severe injuries, although the number of severe and minor injuries that were treated nonoperatively was stable (Fig 6, B). When we stratified the nonoperatively managed blunt splenic injuries by magnitude of the splenic injury, we found that patient age increased over time for minor and moderate splenic injuries (865.01; 32.1 ⫾ 2.3 years in 1993 vs 39.4 ⫾ 2.4 years in 2001 [P ⫽ .001]; 865.02; 28.9 ⫾ 1.5 years in 1993 vs 32.6 ⫾ 0.9 years in 2001 [P ⫽ .024]), although age in patients with
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Fig 6. Splenic injury management. A, The percentage of patients with blunt splenic injuries who underwent an operative procedure on the spleen is shown (). Of those who underwent operative treatment of their spleen injury, the percentage who had a splenectomy () and splenorrhaphy (Œ) is demonstrated. B, The number of patients who were treated nonoperatively with blunt splenic injuries that was identified as ICD-9-CM 865.01 (Œ), 865.02 (Œ), 865.03 (□), and 865.04 ().
severe injuries was unchanged (data not shown). There was a decrease in ISS over time only for moderate injuries (865.02, 23.2 ⫾ 1.4 in 1993 vs 20.8 ⫾ 0.6 in 2001; P ⫽ .017); ISS for all other injuries was unchanged. Importantly, the mortality rate that was associated with nonoperative management of blunt splenic injuries decreased only for moderately severe injuries (865.02, 16.9% mortality in 1993 vs 8.8% mortality in 2001; P ⬍ .001); the mortality rates that were associated with all other injuries did not change over time (865.01, 8.2% mortality; 865.03, 8.7% mortality; 865.04, 32.2% mortality).
Harbrecht et al 235
DISCUSSION The management of splenic injuries has clearly changed over the last 2 decades.1-6 What has not been evaluated, however, is whether overall outcome or the pattern of splenic injuries that were seen in trauma centers over the same time period also changed. Our report covers the 15 years in which a state trauma system in Pennsylvania has existed and includes ⬎11,000 patients with splenic injuries. These data allow us to make several novel observations. There has been an increase in the number of splenic injuries that have been diagnosed in Pennsylvania trauma centers. The increase in splenic injuries reflects not only an increase in the total number of patients whose data was entered into the PTOS database but also an increase in the frequency with which these patients were diagnosed with splenic injuries. The transition from the use of physical examination and diagnostic peritoneal lavage to CT as the primary diagnostic modality for injured patients with potential intraabdominal injury is reflected in this dataset14 and contributes to the changing pattern of splenic injuries that has been seen over time. The mortality rate that is associated with splenic injuries has also decreased over time (Table I). Our data demonstrate a substantial rise in the number of moderate (865.02) splenic injuries. Interestingly, the number of severe (865.04) and minor (865.01) splenic injuries has remained fairly constant over the 15-year study period. Most of the demographic changes in the population of patients with splenic injuries as a whole are identical to the changes that have been seen in patients with moderate splenic injuries. The mortality rate, ISS, and ED blood pressure that were associated with both minor and severe splenic injuries did not change over time. The decreasing mortality rate and ISS for the entire group, however, corresponded to that seen in patients with moderate injuries in which mortality rate decreased and ED blood pressure significantly increased over time. Moderate splenic injuries (865.02) now comprise ⬎60% of all splenic injuries that are diagnosed in patients whose data are entered into this registry. This dramatic shift in injury magnitude was associated with a change in the mechanism of injury for patients with splenic injuries. Although MVC remains the most common form of injury, the relative frequency of patients with splenic injuries involved in MVCs declined as the proportion of patients diagnosed with splenic injuries from falls and other blunt injuries (all-terrain vehicle and bicycle crashes) significantly increased (Fig 5). It is not
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Table II. Management of blunt splenic injuries
Year 1993 1994 1995 1996 1997 1998 1999 2000 2001 Totals
Splenectomy N
Mortality rate (%)
Splenorrhaphy N
Mortality rate (%)
217 249 287 245 267 273 284 218 224
12.4 19.7 22.0 15.1 15.0 18.3 18.3 13.8 25.0 17.8
45 54 40 44 36 23 26 27 16
6.7 1.9 10.0 2.3 5.6 8.7 11.5 3.7 12.5 6.1
surprising therefore that an increase in low-velocity injury mechanisms is associated with a reduction in the overall magnitude of injury to the spleen and contributes to the decline in ISS for the group as a whole. Although the mortality rate for moderately severe splenic injuries improved over time and accounted for the decrease in mortality rate for patients with splenic injuries as a whole, the mortality rate that was associated with minor and severe splenic injuries did not change over time. The reasons for this are unclear. It is likely that death in patients with minor splenic injuries will be determined primarily by associated injuries or comorbid medical conditions and will not be related directly to the splenic injury itself. Death that is associated with severe splenic injuries is more difficult to analyze. Patients with severe splenic injuries can bleed profusely from the spleen and are at risk for exsanguination, shock-induced multiple organ failure, or other hemorrhage-related complications. Actively hemorrhaging patients require expeditious field triage and treatment, swift transport to a trauma center, prompt medical evaluation, and rapid control of hemorrhage. Deficiencies in any of these areas can contribute to morbidity and death. Patients who have been subjected to enough force to severely damage the spleen are also at risk for associated injuries such as other intra-abdominal injuries, chest injuries, or traumatic brain injuries that may dictate death, independent of the splenic injury or splenic injury treatment. The specific cause of death was not available in this dataset, so we cannot determine what the contribution of the splenic injury to mortality rate may be in these cases. The large influx of less severe splenic injuries that are caused by low-velocity accidents and are picked up because of the more widespread use of
Splenic surgery N 262 303 327 289 303 296 310 245 240
Mortality rate (%) 11.5 16.5 20.5 13.1 13.9 17.6 17.7 12.7 24.2 16.4
Nonoperative treatment N 305 392 452 500 546 527 664 700 689
Mortality rate (%)
Patients (%)
19.1 19.1 20.6 16.5 17.2 14.3 12.2 12.5 9.9 15.0
49.8 53.4 55.2 60.0 61.9 61.4 65.5 71.1 72.1
CT has significant implications for the management of splenic trauma. Improvement in the success rate of nonoperative treatment for adults with blunt splenic injuries has been attributed to the use of dedicated trauma surgeons to provide care, the use of standardized treatment guidelines, and a greater application of angiographic embolization for selected injuries.16,17,28,29 However, our data suggest that greater success of nonoperative treatment in adults with blunt splenic injuries may also simply represent the inevitable consequence of trauma centers seeing increasing numbers of patients who have relatively minor splenic injuries from low-velocity accidents. Our data demonstrate that most blunt splenic injuries that are managed nonoperatively are less severe (865.02) injuries (Fig 6, B). Reports of the improved success of nonoperative treatment over time and studies of splenic injury treatment that use historic controls must be interpreted with these changing injury patterns in mind.7,16,17,28,29 The reason for the changes in the population of patients with splenic injuries that were observed in this analysis is not clear. Our results reflect a growing use of CT for diagnosis in patients with splenic injuries. Better epidemiologic studies would be needed to determine whether CT is being used to a greater degree in all injured patients in addition to those patients with splenic injuries, but this hypothesis is consistent with trends in other areas of surgery.30 Whether more patients are being injured or whether the increased use of CT is leading to a greater detection of previously undiagnosed, relatively minor splenic injuries would require a larger, population-based analysis that is beyond the scope of the current study. An increase in the referral of injured patients to trauma centers, more comprehensive evaluation of injured patients at referring hospitals or trauma centers, improved patient ac-
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cess to trauma centers, and widespread dissemination of management/evaluation protocols may also be consequences of the development of a regionalized trauma system that could influence the nature of injured patients who are seen in trauma centers and therefore influence the results of this analysis. There are limitations to this study that must be acknowledged. Submission criteria for the PTOS restrict data entry to the most severely injured patients and those who stay for ⬎48 hours. Patients who have minor injuries and are discharged in ⬍48 hours would not be captured in this database. These criteria would favor the inclusion of patients with more severe splenic injuries. Our data demonstrate relatively stable numbers of patients with minor splenic injuries (865.01), but we cannot exclude the possibility that additional patients with minor injuries may have been discharged early and not captured in this dataset. We used an administrative dataset that is maintained by the state; issues with the accuracy of state data have been identified with other state trauma registries.31 The PTSF not only maintains the PTOS but also establishes standards for trauma center registrar training and continuing education that each trauma center must adhere to in order to maintain accreditation. In addition, selected samples of submitted data are reviewed for accuracy and quality by the PTSF at the time of on-site evaluation and accreditation visits that are required a minimum of every 3 years. However, a comprehensive review of all submissions to the PTOS, like that performed elsewhere,31 has not been performed. Although the accuracy of some data elements (ie, lived or died, length of stay) may be relatively easy to ascertain, other data elements such as magnitude of injury may be more difficult to establish. Accurate injury coding requires a thorough description and/or grading of the injury by a physician, legible and accessible documentation, accurate transmission of information from the medical record to the trauma registry, and expert coding personnel. Errors can be introduced at any step in this process. Because the PTOS uses a commercially available software program to convert the injury description provided by the trauma center to ICD-9-CM and AIS codes, our results will also be dependent, in part, on the ability to reliably transmit essential descriptive information and on the accuracy of the software program itself. Although our data may be difficult to compare directly to that of registries that code injuries differently, they appear to be adequate to identify temporal trends within the registry itself. We have identified similar
trends in the magnitude of splenic injuries over time in the National Trauma Data Bank (American College of Surgeons; unpublished data) and in the University of Pittsburgh Medical Center Trauma Registry (unpublished data); these additional analyses support our conclusion that the trends that were identified in this analysis accurately reflect what is seen in trauma centers throughout the state. In summary, over the 15 years that this state trauma system has collected data, there has been an increase in the diagnosis of splenic injuries that are associated with progressive increases in the use of CT scanning. In patients with splenic injuries, there have been a decrease in ISS and a decrease in mortality rates that are primarily a reflection of the substantial increase in splenic injuries of moderate severity. The mortality rate of patients with severe and minor splenic injuries has remained unchanged. The changing demographics of patients with splenic injuries, with proportionally greater numbers of moderately severe injuries from low-velocity accidents, contributes significantly to the improved success of nonoperative management with splenic trauma that currently is being performed in trauma centers. These data were provided by the Pennsylvania Trauma Systems Foundation, Mechanicsburg, PA. The Foundation specifically disclaims responsibility for any analyses, interpretations, and conclusions. Credit must be given to the Pennsylvania Trauma Outcome Study (PTOS) as the source of data. REFERENCES 1. Pachter HL, Guth AA, Hofstetter SR, Spencer FC. Changing patterns in the management of splenic trauma: the impact of nonoperative management. Ann Surg 1998;227:708-19. 2. Konstantokos AK, Barnoski AL, Plaisier BR, Yowler CJ, Fallon WF Jr, Malangoni MA. Optimizing the management of blunt splenic injury in adults and children. Surgery 1999; 126:805-13. 3. Hunt JP, Lentz CW, Cairns BA, et al. Management and outcome of splenic injury: the results of a five-year statewide population based study. Am Surg 1996;62:911-7. 4. Clancy TV, Ramshaw DG, Maxwell JG, et al. Management outcome in splenic injury: a statewide trauma center review. Am Surg 1997;226:17-24. 5. Molin MR, Shackford SR. The management of splenic trauma in a trauma system. Arch Surg 1990;125:840-3. 6. Mangus RS, Mann NC, Worrall W, Mullins RJ. Statewide variation in the treatment of patients hospitalized with spleen injury. Arch Surg 1999;134:1378-84. 7. Harbrecht BG, Zenati MS, Ochoa JB, et al. Management of adult splenic injuries: comparison between level I and level II trauma centers. J Am Coll Surg 2004;198:232-9. 8. Mullins RJ, Veuim-Stone J, Helfand M, et al. Outcome of hospitalized injured patients after institution of a trauma system in an urban area. JAMA 1994;271:1919-24.
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9. Mullins RJ, Veuim-Stone J, Hedges JR, et al. Influence of a statewide trauma system on location of hospitalization and outcome of injured patients. J Trauma 1996;40:536-46. 10. American College of Surgeons Committee on Trauma. Resources for optimal care of the injured patient. Chicago: American College of Surgeons; 1999. 11. Davis JW, Hoyt DB, McArdle MS, et al. An analysis of errors causing morbidity and mortality in a trauma system: a guide for quality improvement. J Trauma 1992;32:660-6. 12. Peitzman AB, Courcoulas AP, Stinson C, Udekwu AO, Billiar TR, Harbrecht BG. Trauma center maturation: quantification of process and outcome. Am Surg 1999;230:87-94. 13. Velmahos GC, Chan LS, Kamel E, et al. Nonoperative management of splenic injuries: Have we gone too far? Arch Surg 2000;135:674-81. 14. Richardson JD. Changes in the management of injuries to the liver and spleen. J Am Coll Surg 2005;200:648-69. 15. Peitzman AB, Harbrecht BG, Rivera L, et al. Failure of observation of blunt splenic injury in adults: variability in practice and adverse consequences. J Am Coll Surg 2005; 201:179-87. 16. Myers JG, Dent DL, Stewart RM, et al. Blunt splenic injuries: dedicated trauma surgeons can achieve a high rate of nonoperative success in patients of all ages. J Trauma 2000; 48:801-6. 17. Nix JA, Costanza M, Daley BJ, Powell MA, Enerson BL. Outcome of the current management of splenic injuries. J Trauma 2001;50:835-42. 18. Davis KA, Fabian TC, Croce MA, et al. Improved success in nonoperative management of blunt splenic injuries: embolization of splenic artery pseudoaneurysms. J Trauma 1998; 44:1008-15. 19. Peitzman AB, Heil B, Rivera L, et al. Blunt splenic injury in adults: multi-institutional study of the Eastern Association for the Surgery of Trauma. J Trauma 2000;49:177-89. 20. Harbrecht BG, Zenati MS, Alarcon LH, et al. Is outcome after blunt splenic injury in adults better in high-volume trauma centers? Am Surg 2005;71:942-9.
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21. Gilliott AR, Thomas JM, Forrester C. Development of a statewide trauma registry. J Trauma 1989;29:1667-72. 22. Pasquale MD, Peitzman AB, Bednarski J, Wasser TE. Outcome analysis of Pennsylvania trauma centers: factors predictive of nonsurvival in seriously injured patients. J Trauma 2001;50:465-74. 23. Mirvis SE, Whitley NO, Gens DR. Blunt splenic trauma in adults: CT-based classification and correlation with prognosis and treatment. Radiology 1989;171:33-9. 24. Kohn JS, Clark DE, Isler RJ, Pope CJ. Is computed tomographic grading of splenic injury useful in the nonsurgical management of blunt trauma? J Trauma 1994;36: 385-90. 25. Federle MP, Courcoulas AP, Powell M, Ferris JV, Peitzman AB. Blunt splenic injury in adults: clinical and CT criteria for management with emphasis on active extravasation. Radiology 1998;206:137-42. 26. Rozycki GS, Ochsner MG, Schmidt JA, et al. A prospective study of surgeon performed ultrasound as the primary adjuvant modality for injured patient assessment. J Trauma 1995;39:492-500. 27. Shackford SR, Rogers FB, Osler TM, Trabulsky ME, Clauss DW, Vane DW. Focused abdominal sonogram for trauma: the learning curve of nonradiologist clinician in detecting hemoperitoneum. J Trauma 1999;46:553-64. 28. Wahl WL, Ahrns KS, Chen S, Hemmila MR, Rowe SA, Arbabi S. Blunt splenic injury: operation versus angiographic embolization. Surgery 2004;136:891-9. 29. Haan JM, Biffl W, Knudson MM, et al. Splenic embolization revisited: a multicenter review. J Trauma 2004;56:542-7. 30. Rao PM, Rhea JT, Novelline RA, Mostafavi AA, McCabe CJ. Effect of computed tomography of the appendix of the appendix on treatment of patients and use of hospital resources. N Engl J Med 1998;338:141-6. 31. Hunt JP, Cherr GS, Hunter C, et al. Accuracy of administrative data in trauma: splenic injuries as an example. J Trauma 2000;49:679-88.
Background. The management of splenic injuries has evolved with a greater emphasis on nonoperative management. Although several institutions have demonstrated that nonoperative management of splenic injuries can be performed with an increasing degree of success, the impact of this treatment shift on outcome for all patients with splenic injuries remains unknown. We hypothesized that outcomes for patients with splenic injuries have improved as the paradigm for splenic injury treatment has shifted. Methods. Consecutive patients from 1987 to 2001 with splenic injuries who were entered into a state trauma registry were reviewed. Demographic variables, injury characteristics, and outcome data were collected. Results. The number of patients who were diagnosed with splenic injuries increased from 1987 through 2001, despite a stable number of institutions submitting data to the registry. The number of minor injuries and severe splenic injuries remained stable, and the number of moderately severe injuries significantly increased over time. Overall mortality rate improved but primarily reflected the decreased mortality rates of moderately severe injuries; the mortality rate for severe splenic injuries was unchanged. Conclusion. Trauma centers are seeing increasing numbers of splenic injuries that are less severe in magnitude, although the number of the most severe splenic injuries is stable. The increased proportion of patients with less severe splenic injuries who are being admitted to trauma centers is a significant factor in the increased use and success rate of nonoperative management. (Surgery 2007;141:229-38.) From the Department of Surgery, University of Pittsburgh, Pittsburgh, Pa
Treatment of the injured patient with a splenic injury over the last several decades has evolved from mandatory surgical exploration and splenectomy for even minor injuries to an emphasis on splenic preservation and a primary role for nonoperative treatment for most patients.1,2 Several large studies on the management of splenic injuries have focused on describing the shift from operative to nonoperative management3-5 or examining specific differences in resource use between trauma centers.6,7 While these changes in the management of splenic injuries have occurred, there has also been Presented in poster format at the 62nd Annual Meeting of the American Association for the Surgery of Trauma, Sept. 11-13, 2003, Minneapolis, MN. Accepted for publication June 30, 2006. Reprint requests: Brian G. Harbrecht, MD, Associate Professor of Surgery, University of Pittsburgh Medical Center, F1264-200 Lothrop St, Pittsburgh, PA 15213. 0039-6060/$ - see front matter © 2007 Mosby, Inc. All rights reserved. doi:10.1016/j.surg.2006.06.032
an increased emphasis on the delivery of organized trauma care, the development of local and regional trauma systems, and the transport of severely injured patients to centers with particular interest and expertise in the care of trauma patients.8-12 The concentration of trauma patients into institutions with specific interest in the care of the injured has helped to promote the evolution in splenic injury management. Several authors have suggested that nonoperative management of splenic injuries has been overemphasized and that morbidity has occurred after attempts to manage inappropriately some splenic injuries nonoperatively.13-15 It is clear, however, that nonoperative treatment has become the most common method of splenic salvage in injured patients.6-8 A number of reports have demonstrated that splenic injuries can be managed nonoperatively with increasing degrees of success.16-20 Intuitively, one would predict that decreasing the frequency of operations would decrease the frequency of postoperative complications and death. The increased emphasis on nonoperative management with hepatic injuries is thought to be the SURGERY 229
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primary factor responsible for the declining mortality rate that has been associated with these injuries over the last several decades.14 The impact of the shift towards nonoperative treatment on outcome for patients with splenic injuries, however, has not been studied thoroughly. The state trauma system in Pennsylvania has been in existence for much of the period in which changes in the diagnosis and management of splenic injuries have evolved and has collected data on injured patients for ⬎15 years. We hypothesized that the mortality rate for patients with splenic injuries who were treated in the state’s trauma centers has decreased. We also sought to determine factors that could contribute to outcome differences over time. MATERIAL AND METHODS The Pennsylvania Trauma Outcome Study (PTOS) is the database that is maintained by the Pennsylvania Trauma Systems Foundation (PTSF) and includes data contributed by all accredited trauma centers in the state.21,22 Briefly, adult and pediatric trauma centers submit data on all patients with a length of stay of ⬎48 hours, injured patients who die, and all admissions to the intensive care unit (ICU).21,22 Patients with splenic injuries were identified by International Classification of Diseases– 9-Clinical Modification (ICD-9-CM) codes (865.XX) from the start of data entry in October of 1986 through 2001. Because data for calendar year 1986 were incomplete, patients from 1986 were excluded, and the analysis was performed on data for patients who were admitted from 1987 to 2001. Demographic information, mechanism of injury, vital signs on admission, procedures performed, and outcome data were collected. The listed E codes were used to identify the mechanism of injury and patients were listed as either motor vehicle crash (MVC; codes xxx.0, xxx.1, xxx.4, xxx.8, xxx.9 for E810-E819; E958.5; and E988.5), motorcycle crash (codes xxx.2 and xxx.3 for E810-E825), pedestrian struck by vehicle (E810-E825, xxx.7), falls (E880-E888, E957, E958, E987.0, and E987.1), assaults (E960, E967, E968), other blunt injuries (allterrain vehicle crashes, bicycle crashes, and all other blunt E codes), stabs (E870.5, E920, E956, E966, and E986), and gunshot wounds (E922, E955, E965.0E965.4, E968.6, E976.0, E985.0-E985.4). Burn injuries were excluded from the analysis. Surgical procedures were included in the database from 1993 to 2001. Operations on the spleen were classified as either splenectomy or splenic repair (splenorrhaphy). Patients who did not have a splenectomy or splenor-
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rhaphy were categorized as having been treated nonoperatively. Registrars at each trauma center performed data abstraction and submission to the PTOS. The PTSF has established guidelines for trauma center accreditation and creates standards for registrar training, registrar continuing education, and the number of trauma registrars, based on institutional volume. For injury-related data, an anatomic description of the injury was abstracted from the medical record and submitted to the PTOS. The PTOS uses a commercially available software program (Tri-Code; Digital Innovation Inc, Forest Hill, Md) to convert the injury description to ICD-9-CM and Abbreviated Injury Scale (AIS) codes. The database used AIS version 1985 from 1986 to 1993 and AIS-90 from 1993 until 2001. We classified splenic injuries as mild (865.x1), moderate (865.x2 and 865.x3), and severe (865.x4). Patients with multiple codes listed for several discreet injuries to the spleen were classified according to the most severe injury. Data are presented as the mean ⫾ SE. Statistical analysis was performed with StatView software (version 5.0; SAS Institute Inc, Cary, NC). Continuous variables were analyzed by analysis of variance and the Tukey-Kramer post hoc test. Categoric variables were analyzed by chi-square and the Fisher’s exact test. A probability value of ⬍.05 was considered statistically significant. RESULTS There were 11,609 patients with splenic injuries whose data were entered into the PTOS database from 1986 through 2001. There were 60 patients whose data were entered in 1986 and 4 patients with burn injury who were excluded. Of the 11,545 patients who remained, 10,652 patients had blunt injury and 893 patients had penetrating injury. The total number of patients whose data were entered into the database per year from all trauma centers increased over the 15-year study interval (Fig 1). The percentage of patients who were diagnosed with splenic injuries increased from 3% of PTOS patients in 1987 to 4.3% in 2001 (Fig 1). Thus, the diagnosis of splenic injury was being made more frequently in patients whose data were entered into the PTOS database. The number of patients who were admitted per year with blunt and penetrating splenic injuries over this interval is shown in Fig 2. The number of patients who were admitted to trauma centers with blunt splenic injuries increased over time; the number of patients who were admitted with penetrating splenic injuries peaked in the early 1990s and then decreased (P ⬍ .001). The increased number of patients with
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Fig 1. Percentage of patients with splenic injuries. The total number of patients whose data were entered into the PTOS database () and the percentage of all patients who were diagnosed with splenic injuries (□) on a yearly basis is shown.
Fig 2. Total number of patients with blunt and penetrating injuries to the spleen over the 15-year study interval.
splenic injuries over time could not be attributed simply to increasing numbers of trauma centers within the state because the number of hospitals designated as trauma centers did not fluctuate significantly over time (Table I). When we examined the demographics of all patients with splenic injuries, there was no difference over time in age, gender, ICU length of stay, or pulse rate measured in the Emergency Department (ED; data not shown). Statistically significant increases in ED systolic blood pressure and significant decreases in injury severity score (ISS) and hospital length of stay were observed (Table I). Overall mortality rate also decreased in a statistically significant manner from 25.6% in 1987 to 13.5% in 2001 (Table I; P ⬍ .01 by chi-square test).
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The decline in mortality rate from 1987 to 2001 could be due to improvements in trauma care over the same time period. However, the increase in ED systolic blood pressure and the decrease in ISS suggest that the improved mortality rate could also be due to decreases in overall magnitude of critical illness or severity of injury for patients with splenic injuries. Because the shift towards nonoperative management of splenic injuries has focused primarily on injuries from blunt-force mechanisms, we analyzed blunt and penetrating injuries separately. To evaluate whether differences in spleen injury severity occurred over time, the magnitude of splenic injury was stratified by the ICD-9-CM code (Fig 3). There were a total of 1652 blunt splenic injuries that were classified as severe (ICD-9-CM 865.04), which accounted for 15.4% of all blunt splenic injuries over the 15-year period. The percentage of severe splenic injuries varied from a low of 8.8% of all injuries in 1990 to a high of 19.2% in years 1994 and 1996 but did not change significantly over the 15-year study period. The percentage of minor blunt splenic injuries (ICD-9-CM 865.01) also remained relatively constant throughout this time period (n ⫽ 1309 patients; 12.2% of all blunt injuries; Fig 3). We classified injuries that were listed as 865.02 and 865.03 as moderately severe splenic injuries. There were a total of 2553 splenic injuries that were classified as ICD-9-CM 865.03, which accounted for 23.8% of all blunt splenic injuries, but this diagnosis was recorded less frequently in the later years of study (Fig 3). There was a significant increase over time in the listing of splenic injuries as ICD-9-CM 865.02 (n ⫽ 5194 patients; 48.5% of blunt splenic injuries) that accounted for the substantial increase in total splenic injuries (Fig 3). Thus, the increased frequency of splenic injuries that were being diagnosed in Pennsylvania trauma centers was due to a large increase in less severe, moderate splenic injuries, although the number of severe and minor injuries remained stable over the 15 years of data collection. When we stratified blunt injuries by magnitude of injury, there was no difference over time in age, gender, or ICU length of stay (data not shown) for any magnitude of splenic injury, with the exception that the average age significantly increased in patients with minor splenic injuries (ICD-9-CM 865.01; 27.4 ⫾ 2.3 years in 1987 to 39.2 ⫾ 2.3 years in 2001; P ⬍ .001 by analysis of variance [ANOVA]). There was a statistically significant decrease in the hospital length of stay over time for patients with each magnitude of splenic injury (data not shown). There was also a statistically significant increase in ED systolic blood pressure over the 15-year period for splenic injuries
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Table I. Data for all patients with splenic injury Year
Trauma centers (n)
Systolic blood pressure (mm Hg)
Mortality rate (%)
Injury severity score
Hospital length of stay (d)
1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001
23 28 28 24 24 26 26 26 26 26 26 27 27 27 28
100 ⫾ 2 100 ⫾ 2 109 ⫾ 2 108 ⫾ 2 105 ⫾ 2 105 ⫾ 2 110 ⫾ 2*† 112 ⫾ 2*† 111 ⫾ 1*† 113 ⫾ 1*†‡ 115 ⫾ 1*†‡ 117 ⫾ 1*†‡储 117 ⫾ 1*†‡储 116 ⫾ 1*†‡储 118 ⫾ 1*†‡储
25.6 25.8 19.9 20.2 23.3 21.3 15.6 17.6 20.0 15.4 15.9 15.1 14.2 13.0 13.5
28.3 ⫾ 0.8 28.7 ⫾ 0.7 26.4 ⫾ 0.6 27.1 ⫾ 0.6 27.2 ⫾ 0.6 27.2 ⫾ 0.6 27.0 ⫾ 0.7 27.1 ⫾ 0.6 28.1 ⫾ 0.6 27.8 ⫾ 0.6 27.0 ⫾ 0.5 27.1 ⫾ 0.5 25.1 ⫾ 0.5¶ 25.4 ⫾ 0.5** 24.9 ⫾ 0.5¶
14.0 ⫾ 0.9 15.5 ⫾ 1.1 13.8 ⫾ 0.6 14.6 ⫾ 0.8 14.0 ⫾ 1.7 12.9 ⫾ 0.6 13.2 ⫾ 0.6 11.6 ⫾ 0.5† 11.5 ⫾ 0.5† 10.6 ⫾ 0.4†§ 10.5 ⫾ 0.4†§储 10.1 ⫾0.4*†§储 9.5 ⫾ 0.4*†§储# 10.0 ⫾ 0.4*†§储# 9.2 ⫾ 0.4*†§储#
*P ⬍ .05 versus 1987. †P ⬍ .05 versus 1988. ‡P ⬍ .05 versus 1991, 1992. §P ⬍ .05 versus 1991. 储P ⬍ .05 versus 1989, 1990. ¶P ⬍ .05 versus 1987, 1988, 1995, 1996. #P ⬍ .05 versus 1992, 1993. **P ⬍ .05 versus 1988, 1995.
classified as 865.02 (108 ⫾ 5 mm Hg in 1987 vs 120 ⫾ 1 mm Hg in 2001; P ⬍ 05) and 865.03 (95 ⫾ 3 mm Hg in 1987 vs 118 ⫾ 2 mm Hg in 2001; P ⬍ 05), although the ED blood pressure for injuries that were classified as 865.04 was unchanged (99 ⫾ 8 mm Hg in 1987 vs 103 ⫾ 4 mmHg in 2001). There was little change in ISS over time for any magnitude of splenic injury (865.01, 18 ⫾ 2 vs 18 ⫾ 1; 865.02, 24 ⫾ 2 vs 22 ⫾ 1; 865.03, 30 ⫾ 1 vs 28 ⫾ 1; 865.04, 44 ⫾ 2 vs 41 ⫾ 1; 1987 vs 2001, respectively). Blunt injuries were associated with a mortality rate (17.2%) that was significantly less than that of penetrating splenic injuries (24.1%). As expected, the average age of patients who had blunt injury was greater than victims of penetrating splenic injuries (32.5 ⫾ 0.2 years vs 30.6 ⫾ 0.4 years, blunt vs penetrating; P ⫽ .012 by ANOVA). The mortality rate for blunt splenic injuries increased according to the magnitude of the splenic injury (865.01, 10.7%; 865.02, 17.1%; 865.03, 17.7%; 865.04, 21.4%). There was a moderate degree of variation in mortality rates on a yearly basis, but there was no statistically significant difference in mortality rates over time for either severe or minor blunt injuries (Fig 4, A). There was a significant decrease in mortality rates for moderate splenic injuries over time that paralleled the decrease in mortality rates
for the population of patients with splenic injuries as a whole (Fig 4, B). We then evaluated whether the increase in moderate splenic injuries was associated with changes in the injury mechanism. Motor vehicle crashes were the most common mechanism of injury for patients with splenic injuries (Fig 5). The number of patients who were injured in assaults and motorcycle crashes and by being struck by vehicles was relatively constant. Although the total number of patients who had splenic injuries as a consequence of MVC increased over time (Fig 5, A), the yearly percentage of patients with splenic injuries because of MVC decreased. The yearly percentage of patients who were injured in falls and by injuries listed as other (primarily bicycle or all-terrain vehicle crashes) significantly increased over time (P ⫽ .006 by chi-square test; Fig 5, B). There was no significant change in the proportion of patients who had gunshot wounds and stab wounds (data not shown). There were 893 splenic injuries because of penetrating trauma (7.7% of all splenic injuries); most of these injuries (n ⫽ 854; 96%) were minor (865.11). There was no difference in age, ED pulse, or ED systolic blood pressure among patients with penetrating injuries (data not shown). There was a significant decrease in the proportion of women
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Fig 3. Splenic injury severity. The severity of splenic injury was stratified by ICD-9-CM code and plotted over time. A, The total number of patients with splenic injuries (‘) and patients whose injury was listed as ICD9-CM 865.04 (), 865.03 (□), 865.02 (), and 865.01 (Œ) are shown. B, The yearly percentage of all patients with splenic injuries that were listed as ICD-9-CM 865.04 (), 865.03 (□), 865.02 (), and 865.01 (Œ) are shown.
with penetrating splenic injuries, which declined from a high of 20.9% in 1990 to 5.1% in 2001 (P ⬍ .05 by chi-square test). For patients with penetrating splenic injuries (865.11), there was a significant reduction in hospital length of stay (19.3 ⫾ 5.9 days in 1987 vs 14.7 ⫾ 3.0 days in 2001; P ⫽ .039 by ANOVA) but no significant difference in ICU length of stay. Mortality rates averaged 24.1% for penetrating splenic injuries for the duration of this study, and there was no significant difference over time (data not shown). We next examined the methods that had been used to diagnose splenic injuries in this dataset.
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Fig 4. Mortality rate for patients with blunt splenic injury. A, Mortality rates of patients with severe (865.04, ) and minor (865.01, Œ) blunt splenic injuries is shown. B, The mortality rate for all patients with blunt splenic injuries (‘) and moderate severity injuries (865.03, □, and 865.02, ) is shown.
Diagnostic modalities were listed as computed tomography (CT), surgical procedure (diagnostic peritoneal lavage/laparotomy), or ultrasound. All modalities that were used to diagnose splenic injuries in each patient were recorded so that subjects could have ⬎1 diagnostic test listed. A progressive and statistically significant increase in CT imaging in patients with splenic injuries occurred that is consistent with previous studies.23-25 In 1987, 59.1% of patients with splenic injuries underwent CT scanning as part of their treatment; this increased to 89.4% in 2001 (P ⬍ .0001 by chi-square test). As has been described previously, there was a decrease in the use of diagnostic peritoneal lavage/laparot-
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Fig 5. Mechanism of injury in patients with splenic injuries. The mechanism of injury was evaluated by E-code and listed as MVC (), motorcycle crash (‘), pedestrian struck by a vehicle (), assault (□), fall (), and other blunt injuries (Œ). The data are presented as (A) the number of patients with each mechanism and (B) the percentage of patients with each mechanism. The decline in MVCs and the increase in fall/other blunt injuries were statistically significant (P ⫽ .0006 by chisquare test).
omy for the diagnosis of splenic injuries (77.9% of patients in 1987 vs 50.5% in 2001; P ⬍ .001). The use of ultrasound in patients with splenic injuries remained relatively steady from 1990 until 1998 when its use increased, which corresponded with the increased interest in ultrasound to diagnose hemoperitoneum (21.9% in 1990 vs 35.0% in 1998 vs 45.7% in 2001).26,27 The shift in treatment of adult splenic injuries toward nonoperative management and the subsequent decrease in operations on the spleen have
Surgery February 2007 been described previously.1-4 Surgical procedures were listed in this database from 1993 to 2001; to verify that our data are similar to previously published experiences, we reviewed trends in management. For patients with penetrating splenic injuries, there was no difference over time in the frequency of operative treatment, and the proportion of splenectomy and splenorrhaphy remained unchanged (data not shown). For blunt injuries, there was a gradual reduction in the total number of patients who had operations on the spleen, a reduction in the frequency of splenorrhaphy, and an increase in the proportion of patients who underwent an operation who received a splenectomy (Fig 6, A). There was a total of 2264 patients who underwent splenectomy for blunt trauma from 1993 to 2001; in these patients, there was no difference over time in age, gender, ED systolic blood pressure, ED pulse, or ICU length of stay (data not shown). There was a statistically significant increase in ISS (30.1 ⫾ 1.0 in 1993; 33.7 ⫾ 1.0 in 2001; P ⫽ .016 by ANOVA) and a statistically significant decrease in hospital length of stay (16.7 ⫾ 1.1 days in 1993; 12.0 ⫾ 0.9 days in 2001; P ⫽ .028). The mortality for patients who underwent splenectomy for blunt trauma was 17.8%, with significant variability from year to year (Table II). There were 311 patients from 1993 to 2001 who had a splenorrhaphy performed for blunt injuries. There was no difference over time in patient age, gender, ED systolic blood pressure, ED pulse, ISS, ICU length of stay, or hospital length of stay (data not shown). The overall mortality rate for patients who underwent splenorrhaphy was 6.1%, with no change over time (Table II). The decrease in splenic surgical procedures over time corresponded to an increase in patients who were treated nonoperatively (Table II).1-4,14-20 The absolute number and the yearly percentage of patients who were treated nonoperatively after blunt injury to the spleen increased significantly, and this shift was associated with a statistically significant decrease in overall mortality rate (Table II). Most nonoperatively treated blunt injuries were moderately severe injuries, although the number of severe and minor injuries that were treated nonoperatively was stable (Fig 6, B). When we stratified the nonoperatively managed blunt splenic injuries by magnitude of the splenic injury, we found that patient age increased over time for minor and moderate splenic injuries (865.01; 32.1 ⫾ 2.3 years in 1993 vs 39.4 ⫾ 2.4 years in 2001 [P ⫽ .001]; 865.02; 28.9 ⫾ 1.5 years in 1993 vs 32.6 ⫾ 0.9 years in 2001 [P ⫽ .024]), although age in patients with
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Fig 6. Splenic injury management. A, The percentage of patients with blunt splenic injuries who underwent an operative procedure on the spleen is shown (). Of those who underwent operative treatment of their spleen injury, the percentage who had a splenectomy () and splenorrhaphy (Œ) is demonstrated. B, The number of patients who were treated nonoperatively with blunt splenic injuries that was identified as ICD-9-CM 865.01 (Œ), 865.02 (Œ), 865.03 (□), and 865.04 ().
severe injuries was unchanged (data not shown). There was a decrease in ISS over time only for moderate injuries (865.02, 23.2 ⫾ 1.4 in 1993 vs 20.8 ⫾ 0.6 in 2001; P ⫽ .017); ISS for all other injuries was unchanged. Importantly, the mortality rate that was associated with nonoperative management of blunt splenic injuries decreased only for moderately severe injuries (865.02, 16.9% mortality in 1993 vs 8.8% mortality in 2001; P ⬍ .001); the mortality rates that were associated with all other injuries did not change over time (865.01, 8.2% mortality; 865.03, 8.7% mortality; 865.04, 32.2% mortality).
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DISCUSSION The management of splenic injuries has clearly changed over the last 2 decades.1-6 What has not been evaluated, however, is whether overall outcome or the pattern of splenic injuries that were seen in trauma centers over the same time period also changed. Our report covers the 15 years in which a state trauma system in Pennsylvania has existed and includes ⬎11,000 patients with splenic injuries. These data allow us to make several novel observations. There has been an increase in the number of splenic injuries that have been diagnosed in Pennsylvania trauma centers. The increase in splenic injuries reflects not only an increase in the total number of patients whose data was entered into the PTOS database but also an increase in the frequency with which these patients were diagnosed with splenic injuries. The transition from the use of physical examination and diagnostic peritoneal lavage to CT as the primary diagnostic modality for injured patients with potential intraabdominal injury is reflected in this dataset14 and contributes to the changing pattern of splenic injuries that has been seen over time. The mortality rate that is associated with splenic injuries has also decreased over time (Table I). Our data demonstrate a substantial rise in the number of moderate (865.02) splenic injuries. Interestingly, the number of severe (865.04) and minor (865.01) splenic injuries has remained fairly constant over the 15-year study period. Most of the demographic changes in the population of patients with splenic injuries as a whole are identical to the changes that have been seen in patients with moderate splenic injuries. The mortality rate, ISS, and ED blood pressure that were associated with both minor and severe splenic injuries did not change over time. The decreasing mortality rate and ISS for the entire group, however, corresponded to that seen in patients with moderate injuries in which mortality rate decreased and ED blood pressure significantly increased over time. Moderate splenic injuries (865.02) now comprise ⬎60% of all splenic injuries that are diagnosed in patients whose data are entered into this registry. This dramatic shift in injury magnitude was associated with a change in the mechanism of injury for patients with splenic injuries. Although MVC remains the most common form of injury, the relative frequency of patients with splenic injuries involved in MVCs declined as the proportion of patients diagnosed with splenic injuries from falls and other blunt injuries (all-terrain vehicle and bicycle crashes) significantly increased (Fig 5). It is not
236 Harbrecht et al
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Table II. Management of blunt splenic injuries
Year 1993 1994 1995 1996 1997 1998 1999 2000 2001 Totals
Splenectomy N
Mortality rate (%)
Splenorrhaphy N
Mortality rate (%)
217 249 287 245 267 273 284 218 224
12.4 19.7 22.0 15.1 15.0 18.3 18.3 13.8 25.0 17.8
45 54 40 44 36 23 26 27 16
6.7 1.9 10.0 2.3 5.6 8.7 11.5 3.7 12.5 6.1
surprising therefore that an increase in low-velocity injury mechanisms is associated with a reduction in the overall magnitude of injury to the spleen and contributes to the decline in ISS for the group as a whole. Although the mortality rate for moderately severe splenic injuries improved over time and accounted for the decrease in mortality rate for patients with splenic injuries as a whole, the mortality rate that was associated with minor and severe splenic injuries did not change over time. The reasons for this are unclear. It is likely that death in patients with minor splenic injuries will be determined primarily by associated injuries or comorbid medical conditions and will not be related directly to the splenic injury itself. Death that is associated with severe splenic injuries is more difficult to analyze. Patients with severe splenic injuries can bleed profusely from the spleen and are at risk for exsanguination, shock-induced multiple organ failure, or other hemorrhage-related complications. Actively hemorrhaging patients require expeditious field triage and treatment, swift transport to a trauma center, prompt medical evaluation, and rapid control of hemorrhage. Deficiencies in any of these areas can contribute to morbidity and death. Patients who have been subjected to enough force to severely damage the spleen are also at risk for associated injuries such as other intra-abdominal injuries, chest injuries, or traumatic brain injuries that may dictate death, independent of the splenic injury or splenic injury treatment. The specific cause of death was not available in this dataset, so we cannot determine what the contribution of the splenic injury to mortality rate may be in these cases. The large influx of less severe splenic injuries that are caused by low-velocity accidents and are picked up because of the more widespread use of
Splenic surgery N 262 303 327 289 303 296 310 245 240
Mortality rate (%) 11.5 16.5 20.5 13.1 13.9 17.6 17.7 12.7 24.2 16.4
Nonoperative treatment N 305 392 452 500 546 527 664 700 689
Mortality rate (%)
Patients (%)
19.1 19.1 20.6 16.5 17.2 14.3 12.2 12.5 9.9 15.0
49.8 53.4 55.2 60.0 61.9 61.4 65.5 71.1 72.1
CT has significant implications for the management of splenic trauma. Improvement in the success rate of nonoperative treatment for adults with blunt splenic injuries has been attributed to the use of dedicated trauma surgeons to provide care, the use of standardized treatment guidelines, and a greater application of angiographic embolization for selected injuries.16,17,28,29 However, our data suggest that greater success of nonoperative treatment in adults with blunt splenic injuries may also simply represent the inevitable consequence of trauma centers seeing increasing numbers of patients who have relatively minor splenic injuries from low-velocity accidents. Our data demonstrate that most blunt splenic injuries that are managed nonoperatively are less severe (865.02) injuries (Fig 6, B). Reports of the improved success of nonoperative treatment over time and studies of splenic injury treatment that use historic controls must be interpreted with these changing injury patterns in mind.7,16,17,28,29 The reason for the changes in the population of patients with splenic injuries that were observed in this analysis is not clear. Our results reflect a growing use of CT for diagnosis in patients with splenic injuries. Better epidemiologic studies would be needed to determine whether CT is being used to a greater degree in all injured patients in addition to those patients with splenic injuries, but this hypothesis is consistent with trends in other areas of surgery.30 Whether more patients are being injured or whether the increased use of CT is leading to a greater detection of previously undiagnosed, relatively minor splenic injuries would require a larger, population-based analysis that is beyond the scope of the current study. An increase in the referral of injured patients to trauma centers, more comprehensive evaluation of injured patients at referring hospitals or trauma centers, improved patient ac-
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cess to trauma centers, and widespread dissemination of management/evaluation protocols may also be consequences of the development of a regionalized trauma system that could influence the nature of injured patients who are seen in trauma centers and therefore influence the results of this analysis. There are limitations to this study that must be acknowledged. Submission criteria for the PTOS restrict data entry to the most severely injured patients and those who stay for ⬎48 hours. Patients who have minor injuries and are discharged in ⬍48 hours would not be captured in this database. These criteria would favor the inclusion of patients with more severe splenic injuries. Our data demonstrate relatively stable numbers of patients with minor splenic injuries (865.01), but we cannot exclude the possibility that additional patients with minor injuries may have been discharged early and not captured in this dataset. We used an administrative dataset that is maintained by the state; issues with the accuracy of state data have been identified with other state trauma registries.31 The PTSF not only maintains the PTOS but also establishes standards for trauma center registrar training and continuing education that each trauma center must adhere to in order to maintain accreditation. In addition, selected samples of submitted data are reviewed for accuracy and quality by the PTSF at the time of on-site evaluation and accreditation visits that are required a minimum of every 3 years. However, a comprehensive review of all submissions to the PTOS, like that performed elsewhere,31 has not been performed. Although the accuracy of some data elements (ie, lived or died, length of stay) may be relatively easy to ascertain, other data elements such as magnitude of injury may be more difficult to establish. Accurate injury coding requires a thorough description and/or grading of the injury by a physician, legible and accessible documentation, accurate transmission of information from the medical record to the trauma registry, and expert coding personnel. Errors can be introduced at any step in this process. Because the PTOS uses a commercially available software program to convert the injury description provided by the trauma center to ICD-9-CM and AIS codes, our results will also be dependent, in part, on the ability to reliably transmit essential descriptive information and on the accuracy of the software program itself. Although our data may be difficult to compare directly to that of registries that code injuries differently, they appear to be adequate to identify temporal trends within the registry itself. We have identified similar
trends in the magnitude of splenic injuries over time in the National Trauma Data Bank (American College of Surgeons; unpublished data) and in the University of Pittsburgh Medical Center Trauma Registry (unpublished data); these additional analyses support our conclusion that the trends that were identified in this analysis accurately reflect what is seen in trauma centers throughout the state. In summary, over the 15 years that this state trauma system has collected data, there has been an increase in the diagnosis of splenic injuries that are associated with progressive increases in the use of CT scanning. In patients with splenic injuries, there have been a decrease in ISS and a decrease in mortality rates that are primarily a reflection of the substantial increase in splenic injuries of moderate severity. The mortality rate of patients with severe and minor splenic injuries has remained unchanged. The changing demographics of patients with splenic injuries, with proportionally greater numbers of moderately severe injuries from low-velocity accidents, contributes significantly to the improved success of nonoperative management with splenic trauma that currently is being performed in trauma centers. These data were provided by the Pennsylvania Trauma Systems Foundation, Mechanicsburg, PA. The Foundation specifically disclaims responsibility for any analyses, interpretations, and conclusions. Credit must be given to the Pennsylvania Trauma Outcome Study (PTOS) as the source of data. REFERENCES 1. Pachter HL, Guth AA, Hofstetter SR, Spencer FC. Changing patterns in the management of splenic trauma: the impact of nonoperative management. Ann Surg 1998;227:708-19. 2. Konstantokos AK, Barnoski AL, Plaisier BR, Yowler CJ, Fallon WF Jr, Malangoni MA. Optimizing the management of blunt splenic injury in adults and children. Surgery 1999; 126:805-13. 3. Hunt JP, Lentz CW, Cairns BA, et al. Management and outcome of splenic injury: the results of a five-year statewide population based study. Am Surg 1996;62:911-7. 4. Clancy TV, Ramshaw DG, Maxwell JG, et al. Management outcome in splenic injury: a statewide trauma center review. Am Surg 1997;226:17-24. 5. Molin MR, Shackford SR. The management of splenic trauma in a trauma system. Arch Surg 1990;125:840-3. 6. Mangus RS, Mann NC, Worrall W, Mullins RJ. Statewide variation in the treatment of patients hospitalized with spleen injury. Arch Surg 1999;134:1378-84. 7. Harbrecht BG, Zenati MS, Ochoa JB, et al. Management of adult splenic injuries: comparison between level I and level II trauma centers. J Am Coll Surg 2004;198:232-9. 8. Mullins RJ, Veuim-Stone J, Helfand M, et al. Outcome of hospitalized injured patients after institution of a trauma system in an urban area. JAMA 1994;271:1919-24.
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