Therapeutic strategies for pseudoaneurysm following blunt liver and spleen injuries: A multicenter cohort study in the pediatric population.

BACKGROUND: Little guidance exists for the treatment of pseudoaneurysm (PA) following pediatric blunt liver and/or spleen injuries (BLSIs). We aimed to describe the incidence of delayed PA development and the subsequent clinical course of PA in pediatric BLSIs. METHODS: This multicenter retrospective cohort study from Japan included pediatric patients (16 years and younger) who sustained BLSIs from 2008 to 2019. The cohort was divided into four groups based on hemostatic intervention within 48 hours of admission, namely, nonoperative management (NOM), NOM with interventional radiology (IR), operative management (OM), and combined IR/OM. Descriptive statistics were used to describe the incidence of delayed PA among the groups and to characterize the clinical course of any PAs. RESULTS: A total of 1,407 children (median age, 9 years) from 83 institutions were included. The overall number (incidence) of cases of delayed PA formation was 80 (5.7%), and the number with delayed PA rupture was 16 cases (1.1%) in the entire cohort. Patients treated with NOM (1,056), NOM with IR (276), OM (53), and combined IR/OM (22) developed 43 (4.1%), 32 (12%), 2 (3.8%), and 3 (14%) delayed PAs, respectively. Among patients who developed any PAs, 39% of patients underwent prophylactic IR for unruptured PA, while 13% required emergency angioembolization for delayed PA rupture, with one ruptured case requiring total splenectomy. At least 45% of patients experienced spontaneous resolution of PA without any interventions. CONCLUSION: Our results suggest that the risk of delayed PA still exists even after acute phase IR as an adjunct to NOM for BLSIs in children, indicating the necessity of a period of further observation. While endovascular interventions are usually successful for PA management, including rupture cases, given the high incidence of spontaneous resolution, the ideal management of PA remains to be investigated in future studies. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

Dispatch of Helicopter Emergency Medical Services Via Advanced Automatic Collision Notification.

BACKGROUND: Advanced automatic collision notification (AACN) is a system for predicting occupant injury from collision information. If the helicopter emergency medical services (HEMS) physician can be alerted by AACN, it may be possible to reduce the time to patient contact. OBJECTIVE: The purpose of this study was to validate the feasibility of early HEMS dispatch via AACN. METHODS: A full-scale validation study was conducted. A car equipped with AACN was made to collide with a wall. Immediately after the collision, the HEMS was alerted directly by the operation center, which received the information from AACN. Elapsed times were recorded and compared with those inferred from the normal, real-world HEMS emergency request process. RESULTS: AACN information was sent to the operation center only 7 s after the collision; the HEMS was dispatched after 3 min. The helicopter landed at the temporary helipad 18 min later. Finally, medical intervention was started 21 min after the collision. Without AACN, it was estimated that the HEMS would be requested 14 min after the collision by fire department personnel. The start of treatment was estimated to be at 32 min, which was 11 min later than that associated with the use of AACN. CONCLUSIONS: The dispatch of the HEMS using the AACN can shorten the start time of treatment for patients in motor vehicle collisions. This study demonstrated that it is feasible to automatically alert and activate the HEMS via AACN.

Evaluation of the safety and feasibility of resuscitative endovascular balloon occlusion of the aorta.

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is one of the ultimately invasive procedures for managing a noncompressive torso injury. Since it is less invasive than resuscitative open aortic cross-clamping, its clinical application is expected. METHODS: We retrospectively evaluated the safety and clinical feasibility of REBOA (intra-aortic occlusion balloon, MERA, Tokyo, Japan) using the Seldinger technique to control severe hemorrhage. Of 5,230 patients admitted to our trauma center in Japan from 2007 to 2013, we included 24 who underwent REBOA primarily. The indications for REBOA were a pelvic ring fracture or hemoperitoneum with hemodynamically instability and impending cardiac arrest. Emergency hemostasis was performed during REBOA in all patients. RESULTS: All 24 patients had a blunt injury, the median age was 59 (interquartile range, 41-71 years), the median Injury Severity Score (ISS) was 47 (interquartile range, 37-52), the 30-day survival rate was 29.2% (n = 7), and the median probability survival rate was 12.5%. Indications for REBOA were hemoperitoneum and pelvic ring fracture in 15 cases and overlap in 8 cases. In 10 cases of death, the balloon could not be deflated in 5 cases. In 19 cases in which the balloon was deflated, the median duration of aortic occlusion was shorter in survivors than in deaths (21 minutes vs. 35 minutes, p = 0.05). The mean systolic blood pressure was significantly increased by REBOA (from 53.1 [21] mm Hg to 98.0 [26.6] mm Hg, p < 0.01). There were three cases with complications (12.5%), one external iliac artery injury and two lower limb ischemias in which lower limb amputation was necessary in all cases. Acute kidney injury developed in all three cases, but failure was not persistent. CONCLUSION: REBOA seems to be feasible for trauma resuscitation and may improve survivorship. However, the serious complication of lower limb ischemia warrants more research on its safety. LEVEL OF EVIDENCE: Therapeutic/care management, level V.

Development of an educational program for the helicopter emergency medical services in Japan.

INTRODUCTION: The Japanese helicopter emergency medical service (HEMS) system provides advanced prehospital treatment at the scene. The education of the dispatched HEMS physicians is important for guaranteeing the quality of medical and safety management, but there is no nationally established training program. This study aimed to determine the validity of the HEMS educational program developed by our team. METHODS: A 3-step educational program was designed for HEMS trainees: step 1, 20 HEMS missions as an observer; step 2, 80 missions of on-the-job training; and step 3, certifying examination conducted by a supervisor. As an evaluation standard, scene time, defined as time from landing at the scene to taking off for a hospital, was determined retrospectively. RESULTS: For trainees, scene time was significantly longer (16.3 ± 5.4 min, 95% CI 15.5-17.1) than for experts (doctors who completed >200 HEMS missions; 15.2 ± 6.7 min, 95% CI 14.7-15.8; P = 0.040) but was significantly shorter than for doctors trained before establishment of the HEMS program (17.5 ± 7.0 min, 95% CI 16.9-18.2; P = 0.030). In cases of trauma or intrinsic disease, there was no significant difference in scene time between trainees (17.4 ± 5.6 min and 14.9 ± 4.8 min, respectively) and experts (16.4 ± 7.8 min and 14.2 ± 5.5 min, respectively). CONCLUSION: The finding that scene time was shortened for program trainees demonstrates the validity of our HEMS educational program. The quality of HEMS missions will be better ensured through this educational system.

Identification of bradykinin receptors in clinical cancer specimens and murine tumor tissues.

Bradykinin (BK) has multiple pathophysiologic functions such as induction of vascular permeability and mitogenesis, and it triggers the release of other mediators such as nitric oxide in inflammatory and cancer tissues. To explore the pathophysiologic roles of BK in tumor, we examined the distribution of BK B2 receptors in human adenocarcinoma (lung, stomach), lymphoma (lymph node), hepatoma, squamous cell carcinoma (lung) and carcinoid (duodenum), and in mouse colon adenocarcinoma 38 (C-38) and sarcoma 180 (S-180) tumor tissues. Immunohistochemical staining of tumor tissues with an anti-BK B2 receptor antibody, or autoradiography with the B2 receptor antagonist [125I]HOE 140 (D-Arg-[Hyp Thi D-Tic Oic8]-BK) and the B2 receptor agonist [3H]BK indicated the presence of B2 receptors in all human tumor cells and murine S-180 and C-38 cells. Specific binding of [3H]HOE 140 was observed in S-180 cells with a Kd of 2.1 nM. Binding of [125I]HOE 140 to S-180 cells was competed by an excess amount (20-100 times) of nonradiolabeled HOE 140 or BK, but not by BK B1 receptor agonist des-Arg9-BK. These results provide direct evidence that the BK B2 receptor is expressed in human cancer and experimental murine tumors, which suggests a potential role for BK in inducing pathologic signal transduction in cancer growth and progression, nitric oxide production and vascular permeability enhancement in tumors. BK antagonists may thus have applications in the modulation of cancer growth and in paraneoplastic syndromes.