Early civilian prehospital reports demonstrated that trained physician‑led teams could place REBOA outside the hospital in highly selected patients [8,9]. In the 2019 London series, REBOA was attempted in 19 patients with exsanguinating pelvic hemorrhage and was successfully deployed in 13; survival was reported in 8 of 13 successful cases and 2 of 6 failed attempts, but the comparison is profoundly confounded by access success, physiology, injury pattern, and survivorship [10]. Distal arterial thrombus requiring thrombectomy was reported in 10 of 13 successful cases, making vascular safety inseparable from feasibility.

The 2024 prospective prehospital cohort focused on Zone I complete followed by partial REBOA in patients with suspected exsanguinating subdiaphragmatic hemorrhage and recent or imminent traumatic cardiac arrest. Eleven of 14 attempted REBOA cases achieved balloon inflation, partial REBOA was achieved in 8 of 11, and 2 of 11 survived to hospital discharge [11]. The study demonstrates procedural capability in a mature expert system; it does not establish a mortality benefit or generalizability to services without comparable training, blood, monitoring, governance, and receiving pathways.

Combat and austere military reports provide some of the clearest examples of REBOA as an operational bridge. Manley and colleagues reported four out‑of‑hospital combat casualties with successful deployment, 18–65 minutes of balloon inflation, and survival to the next echelon without reported access or REBOA complications [12]. The de Schoutheete series described three austere military prehospital uses with dynamic partial occlusion and successful deployment, but two sheath‑site thromboses [13]. Northern and colleagues described aortic balloon occlusion within broader special‑operations damage‑control resuscitation, while case reports from mass‑casualty and rotary‑wing settings illustrated operator and platform feasibility [14–16].

Additional combat experience has expanded the implementation map. A Russian series described three battlefield casualties treated in a field hospital; two survived to discharge and no REBOA‑related complication was reported [17]. A 2024 Ukrainian series included five mine‑blast casualties treated at Role 1 or 2 facilities; four were evacuated after REBOA, occlusion times ranged from 15 to 50 minutes, and one femoral artery thrombosis was reported [18]. A 2025 Ukrainian case used five minutes of complete and 50 minutes of partial Zone I occlusion, including transport, with distal pressure titration and survival through the early postoperative period [19]. These reports are valuable for logistics and workflow, but their small, selected denominators preclude treatment‑effect inference.

Interfacility transfer is a distinct use case because the balloon may function as a contingency rather than continuous full occlusion. A five‑patient rural transfer program reported that all patients reached a Level I trauma center, with close coordination among the referring, transport, and receiving teams [20]. This model depended on predefined activation, trained escorts, blood products, communication, and a destination capable of immediate definitive care.

Resource‑constrained trauma‑center evidence is heterogeneous. International registry work compared REBOA‑treated patients across country‑income contexts and highlighted differences in access strategy and management, but it did not compare REBOA with no REBOA [21]. Colombian studies described a transition from larger to lower‑profile access and a retrospective adjusted mortality association in penetrating trauma; both are vulnerable to era effects, learning curves, and confounding by indication [22,23].

Recent reports extend the evidence beyond earlier mapping. A 23‑patient Thai cohort from a tertiary center reported an average systolic blood‑pressure increase of 39.8 mmHg, return of spontaneous circulation in 19 patients, 24‑hour survival in 6, and 28‑day survival in 5. Acute kidney injury occurred in 5 patients and no lower‑limb ischemia was reported [24]. A 2026 Ecuador case demonstrated technical feasibility in a second‑level hospital without interventional radiology, but the patient arrived after an approximately 8‑hour delay and died of multiorgan failure, underscoring that procedural capability cannot compensate for a failed trauma system [25]. A Spanish HEMS (Helicopter Emergency Medical Service) document‑based study identified 103 potential candidates among 2,303 patients but involved no actual REBOA deployment; it informs case‑volume planning rather than clinical effectiveness [26]. Representative clinical and implementation evidence is summarized in Table 1.

Across reports with extractable attempt denominators, technical success ranged from 13 of 19 in the 2019 civilian prehospital series to 4 of 4 and 3 of 3 in very small military series, with 11 of 14 successful Zone I inflations in the 2024 prehospital cohort [10–13]. Early arterial access has also been associated with greater REBOA utilization in battlefield casualties [27]. These proportions should not be pooled because “attempt,” “access,” “deployment,” and “successful inflation” were defined differently, and several series came from highly selected expert teams. The reproducible conclusion is narrower: deployment can be achieved in selected systems that invest in access competence, equipment, rehearsal, and destination readiness.

Study‑specific deployment proportions are shown in Figure 2, and selected descriptive quantitative signals are summarized in Table 2.

Immediate systolic blood‑pressure improvement or stabilization is consistently described in uncontrolled reports [10–13,19,24]. This is mechanistically plausible and clinically useful during profound shock, but it is a surrogate outcome. A rise in proximal pressure does not demonstrate improved neurologically intact survival, nor does it quantify distal ischemic cost, delay to definitive control, or complications caused by access and reperfusion.

Beyond temporary hemorrhage control, aortic occlusion redistributes a limited circulating volume toward the proximal circulation and can increase central arterial pressure, coronary perfusion pressure, carotid flow, and cerebral oxygen delivery. In a porcine model of class IV hemorrhagic shock, balloon occlusion increased central aortic pressure, carotid blood flow, and brain oxygenation compared with no occlusion [28]. A 2026 porcine study using cerebral microdialysis found that Zone 1 total REBOA moved lactate‑pyruvate ratios toward baseline after hemorrhagic shock, including in animals with experimentally elevated intracranial pressure; the study did not establish absence of tissue injury or long‑term neurologic recovery [29]. In a prolonged cardiac‑arrest swine model, inflation increased coronary perfusion pressure and common carotid flow, while animals achieving return of spontaneous circulation (ROSC) had higher coronary perfusion pressure, carotid flow, and end‑tidal carbon dioxide (ETCO₂) than animals without ROSC [30]. These studies support REBOA as a physiologic resuscitation maneuver, but the endpoints remain experimental or surrogate and must be weighed against distal ischemia, reperfusion injury, and time to hemostasis.

In traumatic cardiac arrest (TCA), REBOA may be considered only for narrowly selected patients with presumed subdiaphragmatic hemorrhage after major thoracic bleeding, tension pneumothorax, and pericardial tamponade have been addressed or excluded. In 11 patients with traumatic arrest, high‑fidelity recordings showed that closed‑chest compressions during aortic occlusion generated mean systolic, mean arterial, and diastolic pressures of 70, 43, and 26 mm Hg, respectively [31]. A larger single‑center series reported ROSC in 29 of 50 arrest patients and 30‑day survival in 5; its uncontrolled design and highly selected institutional pathway preclude causal inference [32]. The recent prehospital cohort likewise shows that inflation and partial occlusion can be achieved in selected patients with recent or imminent arrest, but only 2 of 11 inflated cases survived to discharge [11]. Proximal pressure, ETCO₂, and ROSC can therefore be used as real‑time physiologic response signals, not as evidence that REBOA improves neurologically intact survival. Futility rules, uninterrupted resuscitation, and immediate access to definitive hemorrhage control remain essential.

Survival outcomes are reported using a range of endpoints, including survival to transport, 24‑hour survival, 28‑ or 30‑day survival, and survival to hospital discharge. These outcomes are derived from selected case series that differ in injury mechanisms and cardiac arrest status, making direct comparisons across studies inappropriate. The only randomized trial, UK‑REBOA, evaluated an emergency‑department REBOA strategy in major trauma centers rather than an austere program. Ninety‑day mortality was 54% with the REBOA strategy and 42% with standard care; only 19 of 46 patients allocated to REBOA received balloon inflation [1]. The trial does not resolve every expert‑system or partial‑REBOA question, but it decisively rejects the assumption that adding REBOA automatically improves survival.

Access and vascular events are among the most actionable findings. Reported events include sheath‑site thrombosis, distal thrombus requiring thrombectomy, groin complications, and femoral artery thrombosis [10,11,13,18,22]. A prior meta‑analysis estimated groin‑access complications in the range of 4–5%, but definitions and device generations varied [33]. An updated complications review reinforces that access injury, limb ischemia, thrombosis, embolization, and reperfusion injury require deliberate mitigation [34]. Lower‑profile devices might reduce risk, but device size cannot substitute for ultrasound‑guided access, correct common femoral puncture, sheath management, and a vascular rescue pathway.

Selected access and vascular event proportions are shown in Figure 3.

Partial REBOA is attractive where transport or definitive control cannot occur within a short complete‑occlusion window. Recent prehospital and combat reports show that titratable partial occlusion can be maintained during transport [11,19]. However, partial occlusion is not simply “less balloon.” It requires a compatible device, proximal and distal pressure measurement, repeated titration, continuous attention to bleeding and perfusion, and a trained clinician accompanying the patient. Current Joint Trauma System guidance conditionally favors partial over complete occlusion when the required training and equipment exist, suggests distal pulsatile systolic pressure targets of approximately 20–50 mmHg, and emphasizes defined time limits and surveillance [2]. These recommendations should be adapted through local governance rather than copied without system validation.

Training should be competency‑based rather than attendance‑based. A core curriculum should assess candidate selection and exclusions, ultrasound‑guided common femoral access, device preparation and zone selection, complete and partial occlusion, pressure‑guided titration, clock discipline, controlled deflation, vascular aftercare, team communication, and handover. In an 11‑resident pilot, a 12‑hour multimodal curriculum using lectures, case studies, task trainers, and perfused cadavers improved knowledge and achieved correct indication recognition and placement in all participants at the immediate assessment; most participants retained knowledge and skills at four months [35]. A separate 28‑participant course using a puncture model and vascular circuit model shortened procedure time on repeat attempts [37]. These studies demonstrate that performance can be trained and objectively assessed, but neither defines a universal threshold for independent practice.

Credentialing should therefore be local, multidisciplinary, and linked to the actual care pathway. Suggested requirements include completion of a validated course, objective checklist performance, supervised or proctored cases where feasible, and explicit authorization for access, balloon management, and post‑procedure care. Maintenance should combine scheduled low‑frequency simulation, review of access and deployment failures, device drills, and case‑based quality assurance; the optimal retraining interval is not established. Community‑program experience also emphasizes interprofessional roles, team dynamics, financial and equipment planning, and continual quality assurance [36]. In low‑volume or austere systems, loss of proficiency or inability to rescue complications should trigger retraining, restriction, or program suspension.