Temporal changes in hematologic markers after splenectomy, splenic embolization, and observation for trauma

Introduction: The spleen is one of the most commonly injured abdominal solid organs during blunt trauma. Modern management of splenic trauma has evolved to include non-operative therapies, including observation and angioembolization to preclude splenectomy in most cases of blunt splenic injury. Despite the shift in management strategies, relatively little is known about the hematologic changes associated with these various modalities. The aim of this study was to determine if there are significant differences in hematologic characteristics over time based on the treatment modality employed following splenic trauma. We hypothesized that alterations seen in hematologic parameters would vary between observation (OBS), embolization (EMB), and splenectomy (SPL) in the setting of splenic injury. Methods: An institutional review board-approved, retrospective study of routine hematologic indices examined data between March 2000 and December 2014 at three academic trauma centers. A convenience sample of patients with splenic trauma and admission lengths of stay >96 h was selected for inclusion, resulting in a representative sample of each sub-group (OBS, EMB, and SPL). Basic demographics and injury severity data (ISS) were abstracted. Platelet count, red blood cell (RBC) count and RBC indices, and white blood cell (WBC) count with differential were analyzed between the time of admission and a maximum of 1080 h (45 days) post-injury. Comparisons between OBS, EMB, and SPL groups were then performed using non-parametric statistical testing, with statistical significance set at p < 0.05. Results: Data from 130 patients (40 SPL, 40 EMB, and 50 OBS) were analyzed. The median age was 40 years, with 67 % males. Median ISS was 21.5 (21 for SPL, 19 for EMB, and 22 for OBS, p = n/s) and median Glasgow Coma Scale (GCS) was 15. Median splenic injury grade varied by interventional modality (grade 4 for SPL, 3 for EMB, and 2 for OBS, p < 0.05). Inter-group comparisons demonstrated no significant differences in RBC counts. However, mean corpuscular volume (MCV) and RBC distribution width (RDW) were elevated in the SPL and EMB groups (p < 0.01). Similarly, EMB and SPL groups had higher platelet counts than the OBS group (p < 0.01). In aggregate, WBC counts were highest following SPL, followed by EMB and OBS (p < 0.01). Similar trends were noted in neutrophil and monocyte counts (p < 0.01), but not in lymphocyte counts (p = n/s). Conclusion: This study describes important trends and patterns among fundamental hematologic parameters following traumatic splenic injuries managed with SPL, EMB, or OBS. As expected, observed WBC counts were highest following SPL, then EMB, and finally OBS. No differences were noted in RBC count between the three groups, but RDW was significantly greater following SPL compared to EMB and OBS. We also found that MCV was highest following OBS, when compared to EMB or SPL. Finally, our data indicate that platelet counts are similarly elevated for both SPL and EMB, when compared to the OBS group. These results provide an important foundation for further research in this still relatively unexplored area.