Concordance of CT imaging and surgical lesions in penetrating abdominal trauma

OBJECTIVE

The management of penetrating abdominal wounds has greatly benefited from the development of computed tomography (CT), particularly in stable patients. In this setting, the scanner is the reference examination. Our study aims to evaluate the performance of preoperative CT in the assessment of penetrating abdominal lesions.

MATERIAL AND METHODS

Between January 1, 2015 and January 1, 2022, 81 patients were hospitalized following penetrating abdominal trauma at the Army Training Hospitals of Sainte-Anne and Laveran. Fifty-one stable patients who had an abdominopelvic CT scan and thereafter underwent abdominal surgery (laparotomy or laparoscopy) were included. Radiological and surgical data were collected from the electronic record and compared by a descriptive analysis (calculation of the sensitivity, specificity, positive and negative predictive value of the CT for the detection of lesions of the various organs) and by a correlation of the CT findings with surgical findings using Kripendorff's alpha coefficient.

RESULTS

The cohort was largely male (n=45; 88%), with injuries by knife wound in 62.7% of cases (n=32) and gunshot in 35.3% (n=18) of cases. The median age was 36years (25-47). The median index of severity score (ISS) was 17 (10-26). Excellent agreement between predicted and actual findings was obtained for solid organs (α=0.801) with high sensitivity and specificity (81.8% and 96.6%, respectively). The largest discrepancies were observed for the hollow organs (α=26.2%, sensitivity of 53.3% and specificity of 76.2%) and the diaphragm (α=67.3%, sensitivity 75%, specificity 92.3%). Surgical exploration was non-therapeutic for five patients (9.8%). The failure rate for non-operative treatment was 10% (n=1).

CONCLUSION

CT detection of solid organ lesions in patients with penetrating abdominal wounds is excellent. However, the detection of hollow organ and diaphragmatic wounds remains a challenge with a risk of over- and underdiagnosis. Laparoscopic exploration should be able to fill in the gaps in the CT findings.

Accuracy of CT Scan for Detecting Hollow Viscus Injury in Penetrating Abdominal Trauma

BACKGROUND

In penetrating abdominal trauma, computed tomography (CT) is routinely performed to evaluate stable patients for selective non-operative management (SNOM). Triple-contrast CT (oral, rectal, and IV) has traditionally been used. However, due to its disadvantages, most trauma centres, including our unit at the Charlotte Maxeke Johannesburg Academic Hospital (CMJAH), now perform single-contrast intravenous-only CT scans. We performed a retrospective review to determine the accuracy of single-contrast CT scans for detecting hollow viscus injuries (HVI) in penetrating abdominal trauma.

METHODS

A retrospective review of all patients who presented to CMJAH with penetrating abdominal injuries was performed between 01 August 2017 and 31 August 2019 and were evaluated for SNOM with CT (IV contrast only). Patient records were reviewed to determine pertinent demographics, mechanism, and site of injury, as well as metabolic parameters. CT findings were compared to findings at laparotomy.

RESULTS

A total of 437 patients met the inclusion criteria. The majority were male (92.7%), with a mean age of 31.5 yrs (SD 8.7). Injuries were predominantly due to stab wounds (72,5%, n = 317). CT scan was negative in 342 patients, of which 314 completed SNOM successfully. A total of 93 patients proceeded to laparotomy. CT had a sensitivity of 95.1%, specificity of 44.2%, positive predictive value of 57.4%, and negative predictive value of 92%.

CONCLUSION

Single-contrast CT in penetrating abdominal trauma is a valuable investigative tool in identifying patients for SNOM. Features of HVI on single-contrast CT are not very specific and should be interpreted along with other clinical factors including wound trajectory and serial abdominal examinations. Other associated injuries such as diaphragmatic and solid organ injuries should be considered in the final management plan.

CT of Penetrating Abdominopelvic Trauma

Penetrating abdominopelvic trauma usually results from abdominal cavity violation from a firearm injury or a stab wound and is a leading cause of morbidity and mortality from traumatic injuries. Penetrating trauma can have subtle or complex imaging findings, posing a diagnostic challenge for radiologists. Contrast-enhanced CT is the modality of choice for evaluating penetrating injuries, with good sensitivity and specificity for solid-organ and hollow viscus injuries. Familiarity with the projectile kinetics of penetrating injuries is an important skill set for radiologists and aids in the diagnosis of both overt and subtle injuries. CT trajectography is a useful tool in CT interpretation that allows the identification of subtle injuries from the transfer of kinetic injury from the projectile to surrounding tissue. In CT trajectography, after the entry and exit wounds are delineated, the two points can be connected by placing cross-cursors and swiveling the cut planes obliquely in orthogonal planes to obtain a double-oblique orientation to visualize the wound track in profile. The path of the projectile and its ensuing damage is not always straight, and the imaging characteristics of free fluid of different attenuation in the abdomen (including hemoperitoneum) can support the diagnosis of visceral and vascular injuries. In addition, CT is increasingly used for evaluation of patients after damage control surgery and helps guide the management of injuries that were overlooked at surgery. An invited commentary by Paes and Munera is available online. Online supplemental material is available for this article. ©RSNA, 2021.

Time to surgery: Is it truly crucial in initially stable patients with penetrating injury?

BACKGROUND

Treatment recommendations for patients with penetrating abdominal injury are well established. Trauma victims with clear indications for surgery, should undergo immediate operative intervention without any delay or additional imaging. However, the optimal time for surgery remains unclear. There are some significant advantages in preoperative abdominal CT, including gathering essential information regarding a few difficult to reach anatomical areas, avoiding unnecessary explorations associated with increased morbidity and assessing the existence of extra-abdominal injuries that may have non-expectable impact on initial therapeutic plan. The aim of this study was to determine the impact of "time-to-surgery" on final medical outcomes in patients with penetrating abdominal trauma with normal blood pressure on admission.

METHODS

A retrospective cohort study using the Israeli National Trauma Registry was conducted from 2000- 2018. This study included trauma patients with penetrating injuries and a systolic blood pressure of 90mmHg or above on admission. All patients included in the study were divided into three groups according to the time that lapsed from their admission to surgery: half an hour, an hour, and two hours. We assessed the outcome for each patient, including length of hospital stay, need for intensive care and mortality. Statistical analysis was performed using the Chi-square test, ANOVA test. A p-value of less than 0.05 was considered statistically significant.

RESULTS

The study included 1,136 penetrating trauma patients. Among these, 78.0% (886) had sustained low-energy penetrating injury (SWPI) and 22.0% (250) had sustained high-energy penetrating injury (FAPI). Males accounted for 93.5% (1,062) of the patients. Mean age was 30.4. About 29% (327) of all the patients underwent surgery within 30 minutes from admission, 42% (475) within 30-60 min, and 29% (334) patients were operated within one to two hours. Patients who underwent surgery within 30 minutes, had worse ISS and GCS scores and were, therefore, more likely to have worse clinical outcomes. No other differences in outcomes were found in patients who were operated upon within 2 hours.

CONCLUSIONS

Time to surgery within two hours from admission has no impact on final outcomes in trauma patients with penetrating injury and normal blood pressure on admission.