Point-of-Care Ultrasound in the Diagnosis of Extensive Stanford Type A Aortic Dissection in a Low-Resource Setting: a case report

Technical Summary: Point-of-Care Ultrasound in the Diagnosis of Extensive Stanford Type A Aortic Dissection in a Low-Resource Setting

Problem Statement
Acute aortic dissection (AAD), particularly Stanford Type A, is a life-threatening emergency with high early mortality (1–2% per hour if untreated) and a 30-day mortality approaching 50% without intervention. Diagnosis is frequently delayed or missed, especially in resource-limited settings like sub-Saharan Africa, where Computed Tomography Angiography (CTA)—the diagnostic gold standard—is often inaccessible. Furthermore, AAD frequently presents with atypical symptoms (e.g., gradual onset rather than abrupt tearing pain), complicating clinical suspicion. In West Africa, documented cases are scarce, likely due to profound underdiagnosis rather than a lower disease burden, exacerbated by high rates of uncontrolled hypertension. There is a critical lack of data regarding the utility of Point-of-Care Ultrasound (POCUS) for diagnosing AAD in West African emergency departments.

Methodology
This case report details the clinical management of a 74-year-old Ghanaian male presenting to the Komfo Anokye Teaching Hospital (KATH) with a two-week history of atypical central chest pain, palpitations, and fatigue. The patient had a history of newly diagnosed hypertension, smoking, and alcohol use.

The diagnostic approach relied on the following steps:

1. Clinical Assessment: Standard vital signs and physical examinations were conducted, noting hypertension (160/91 mmHg) but no pulse deficits or murmurs.
2. Initial Investigations: A 12-lead ECG showed normal sinus rhythm. Laboratory results revealed mild normocytic anemia and a mildly elevated troponin I (0.08 ng/mL), which was interpreted as myocardial stress secondary to aortic pathology rather than primary acute coronary syndrome (ACS), given the lack of ischemic ECG changes.
3. POCUS Application: Emergency physicians performed bedside ultrasound using the SPEED protocol (Sonographic Protocol for the Emergent Evaluation of Aortic Dissections). This included:
   • Cardiac windows: Parasternal long-axis (PLAX), parasternal short-axis (PSAX), apical four-chamber, and subxiphoid views.
   • Abdominal windows: Transverse and longitudinal views of the abdominal aorta.
   • FAST examination.
4. Confirmatory Imaging: Due to the in-house CT scanner being non-operational, an urgent CT aortogram was performed at an external facility.
5. Management: Given the inaccessibility of open surgical repair locally, the patient was managed conservatively with aggressive anti-impulse therapy (intravenous beta-blockers targeting SBP <110 mmHg and HR <60 bpm) and optimized oral antihypertensives.

Key Results

• POCUS Findings: The SPEED protocol revealed marked aortic dilatation (5.21–6.35 cm across multiple views) and, crucially, a visible mobile intimal flap separating true and false lumina in the proximal abdominal aorta. No pericardial effusion was detected.
• CTA Confirmation: The CT angiogram confirmed an extensive Stanford Type A (DeBakey I) dissection extending from the aortic root through the thoracoabdominal aorta to the right common iliac artery.
  • Giant Aneurysmal Dilatation: Aortic root (80 mm), ascending aorta (65 mm), aortic arch (70 mm), descending thoracic aorta (73 mm), and abdominal aorta (53 mm).
  • Complications: An intramural hematoma (10.9 cm length) and branch-vessel involvement (coeliac trunk, superior mesenteric artery, and left renal artery arising from the false lumen).
• Clinical Outcome: Despite the extensive nature of the dissection, the patient remained hemodynamically stable. Definitive surgical repair was deemed unfeasible due to local infrastructure limitations. The patient was discharged after 12 days on medical management and remained well at the 30-day follow-up.

Key Contributions

• First Documented Case in Ghana: This represents the first reported instance of an emergency physician-performed POCUS leading to the diagnosis of aortic dissection in a Ghanaian emergency department.
• Validation of SPEED Protocol in Low-Resource Settings: The study demonstrates that the SPEED protocol can be successfully applied in a West African emergency setting to rapidly identify life-threatening aortic pathology, even in cases with atypical, non-abrupt presentations.
• Diagnostic Clarification of Troponin Elevation: The case highlights the importance of correctly attributing mild troponin elevation to aortic root involvement and hemodynamic strain rather than primary ACS, preventing potentially fatal mismanagement (e.g., inappropriate anticoagulation).
• POCUS as a Communication Tool: The authors note that bedside cineloops demonstrating the intimal flap served as a persuasive communication tool during referral negotiations, accelerating acceptance at receiving centers.

Significance and Claims
The paper claims that while the diagnostic tools to identify extensive AAD (specifically POCUS using the SPEED protocol) are achievable and effective in resource-limited settings, a critical diagnostic-therapeutic gap persists: the surgical infrastructure required to treat extensive Type A dissections (cardiopulmonary bypass, deep hypothermic circulatory arrest) remains severely limited across sub-Saharan Africa.

The authors assert that:

1. POCUS is not a substitute for CTA but is an indispensable, potentially life-saving first step when advanced imaging is inaccessible.
2. Expanding emergency POCUS training in the region (e.g., through the West African College of Physicians curriculum) is an achievable, cost-effective near-term priority to reduce diagnostic delays.
3. For patients who are surgically ineligible due to infrastructure constraints, aggressive anti-impulse medical therapy remains the cornerstone of management.

The paper concludes that while the ability to diagnose AAD has advanced in the region, addressing the systemic gap in surgical capacity requires sustained investment.