Presentation Authors: Christopher Loftus*, Niels Johnsen, Seattle, WA
Introduction: The grading of segmental vascular injuries (SVI) following blunt renal trauma represent a controversial topic with the 2011 revised injury staging classification categorizing these as Grade 4 injuries while the original 1989 organ injury scale (OIS) does not mention them at all. Previous work has shown that these injuries in isolation typically do not require urologic intervention. While the current AUA urotrauma guidelines recommend that routine follow-up CT imaging be performed for all high-grade injuries, we sought to examine the utility of repeat imaging in this cohort.
Methods: Patients treated at our level 1 trauma center between 2005 and 2017 were identified by ICD-9/10 codes from our institutional trauma registry. Individual patient charts and imaging were reviewed to identify all patients with SVI due to blunt trauma without associated urinary extravasation or severely graded renal injuries. Patients with penetrating injuries and those who died during the index hospitalization were excluded.
Results: Of 342 patients with Grade 4 renal injuries due to blunt trauma, 61 patients with SVI on initial CT scan were identified. Of these, 46 (76.7%) were male and 38 (63.3%) were due to motor vehicle collision. The mean injury severity score was 36.6 (SD 13.1), with 39 (66.1%) hemodynamically stable at presentation. Repeat follow-up CT scans were performed in 21 (34.4%) patients at a mean 2.8 (SD 2.6) days after admission. No patient underwent urologic intervention or renal angioembolization. Patients who received a routine follow up CT scan had a significantly higher number of abdominal CT imaging during their hospitalization (2.0 vs 1.3, p < 0.0001).Compared to other types of Grade 4 injuries, patients with SVI were less likely to have gross hematuria on presentation (28.3% vs 70.8%, p < 0.0001), had higher ISS on presentation (36.6 vs 28.9, p < 0.0001), and were less likely to have an intervention p < 0.0001. Of the 23 of patients who underwent follow up renograms at a median 100 days after injury, overall renal salvage rate (renogram showing split function >20% in the injured kidney) was 91.3%.
Conclusions: In our experience, patients with isolated SVI following blunt trauma do not benefit from dedicated renal-specific repeat imaging and are unlikely to require urologic or angiographic intervention. These data indicate that routine repeat imaging is not necessary in the absence of clinical signs or symptoms and support prior claims that isolated SVI may be managed as a low-grade injury.