Perioperative consideration of an asymptomatic aortic dissection

Intended learning outcomes

• Common diagnostic imaging modalities used in the diagnosis of aortic dissection.

• Pre-operative risk stratification based on patient factors and disease factors.

• Role of shared decision making models and its application.

Introduction

Aortic dissection is a rare, but life-threatening, condition with an estimated incidence of 2.6–3.5 cases per 100,000 people annually [1]. Most patients present with acute, severe symptoms such as tearing chest, abdominal or pelvic pain, syncope, neurological deficits or stroke [2]. In contrast, asymptomatic presentations are uncommon, accounting for only 4–6% of cases in large registries [3]. Among these, Stanford Type B dissections represent a subset in which therapeutic decisions are often nuanced, balancing medical and surgical strategies.

Type B aortic dissections are stratified into complicated or uncomplicated forms, depending on the presence of rupture, end-organ malperfusion or other life-threatening features. Current international guidelines recommend prompt intervention – either open repair or thoracic endovascular aortic repair (TEVAR) – for complicated cases. In uncomplicated dissections, the standard of care remains optimal medical therapy with the stringent control of blood pressure and heart rate, combined with lifelong imaging surveillance [4]. TEVAR is reserved for cases demonstrating adverse aortic remodelling or high-risk anatomical features [4].

Recent evidence, including from the INSTEAD-XL and ADSORB trials, has suggested that prophylactic TEVAR in selected high-risk uncomplicated type B dissections may confer long-term benefits in terms of aortic remodelling and possibly survival, particularly in younger patients or those with unfavourable anatomy [5, 6]. However, the role of routine early TEVAR remains controversial and must be balanced against procedural risks, especially in patients living with frailty and significant comorbidities.

This report describes a rare case of an asymptomatic, uncomplicated Stanford Type B aortic dissection that was identified incidentally in a patient with multiple comorbidities. Given the heightened perioperative risk, a conservative management strategy with medical therapy and close surveillance was pursued. This case underscores the importance of individualised care, integrating imaging-based risk stratification, frailty assessment and shared decision-making (SDM), which are increasingly central to perioperative and vascular medicine.

Report

A 59-year-old woman with a history of asthma, obstructive sleep apnoea (OSA), heart failure with preserved ejection fraction (HFpEF), obesity with elevated body mass index (BMI) of 40 kg/m², hypertension, hyperlipidaemia and gout presented with a 1-week history of worsening shortness of breath on exertion, associated with symptoms of upper respiratory tract infection. On examination, she was noted to have bilateral expiratory wheeze and was treated for an infective exacerbation of asthma with regular nebulised bronchodilator therapy, oral corticosteroids and oral antibiotics. Significantly, she was also noted to have bilateral pitting oedema up to her mid shins. Further history also revealed a decreased effort tolerance and longstanding orthopnoea. At 13 months before her acute presentation, she was reviewed as an outpatient by cardiology for a follow-up of an incidental finding of a heart murmur. A transthoracic echocardiogram (TTE) demonstrated mild-to-moderate aortic stenosis with a calcified, possibly bicuspid, aortic valve. The echocardiogram also revealed concentric left ventricular hypertrophy, mild mitral regurgitation and mild pulmonary regurgitation. Her left ventricular ejection fraction (LVEF) was 60% at that time. At 14 months before her acute presentation, as part of the same cardiology pathway, she had also undergone dipyridamole myocardial perfusion imaging to evaluate possible ischaemic heart disease, and which showed a normal perfusion status, mildly depressed ejection fraction and dilated left ventricle.

On acute presentation, initial investigations showed an N-terminal prohormone brain natriuretic peptide of 504 ng/L. High-sensitivity troponin was 26.1 ng/L and her electrocardiogram showed a normal sinus rhythm. She underwent a repeat TTE during which a possible dissection in the abdominal aorta was identified. Her LVEF was preserved at 50%, with other findings remaining largely similar to her previous TTE. She then underwent an urgent computed tomography aortogram (CTA), which demonstrated a Stanford B aortic dissection. The dissection entry tear was just distal to the origin of the left subclavian artery, and extending caudally to the bilateral common iliac arteries just proximal to their bifurcations. The diameter of the entry tear measured approximately 0.7 cm. The true lumen along the aorta was smaller compared with the false lumen. The celiac trunk, superior mesenteric artery (SMA), right renal artery and inferior mesenteric artery (IMA) arose from the true lumen. There was a dissection into the ostium of the left renal artery; preserved opacification was noted within the left renal artery distally. On further examination, peripheral pulses in all four limbs were equal, she had no new murmurs and did not complain of any chest discomfort. She also did not have any new focal neurological deficits.

The patient was diagnosed with an asymptomatic incidental Stanford Type B aortic dissection. She was reviewed by the vascular surgery team; antihypertensive medication was commenced targeting a systolic blood pressure of <120 mmHg with close monitoring for signs of visceral and peripheral perfusion deficits, aiming for a long-term systolic blood pressure of <140 mmHg. One week later, she underwent a repeat CTA, which demonstrated that the appearances of the dissection had remained stable since the initial scan and 6-monthly surveillance imaging was recommended. Her case was discussed during a multidisciplinary team meeting involving the radiologist and vascular surgeons to evaluate any perioperative risks. A structured SDM consultation was undertaken with the patient and family to discuss treatment options; in this case the decision was to instigate optimal medical therapy (OMT) and surveillance, rather than perform open or endovascular repair.

Question to be answered

How do we diagnose and manage asymptomatic uncomplicated type B aortic dissection with a shared decision making model?

Discussion

Asymptomatic aortic dissection is rare, but can result in life-threatening complications. This report reviews a case of asymptomatic B aortic dissection, incidentally diagnosed on TTE that demonstrated a possible dissection flap with colour flow in the abdominal aorta (Fig. 1). According to the Society of Vascular Surgery (SVS) and Society of Thoracic Surgery (STS) reporting guidelines, chronic aortic dissection is defined as an intimal tear originating distal to the innominate artery that persists for more than 90 days from symptom onset [7]. In patients with risk factors, clinicians should remain vigilant for asymptomatic chronic dissections and pursue appropriate imaging with TTE or CTA.

Figure 1

Figure 1

Transthoracic echocardiogram demonstrating a possible flap.

The diagnosis of aortic dissection relies heavily on imaging. Chest radiographs may demonstrate a widened aortic silhouette, but CTA remains the first-line modality [8], with a sensitivity of 83–95% and specificity of 87–100%. Magnetic resonance angiography is an alternative procedure with sensitivity and specificity approaching 95–100% [9]. In haemodynamically unstable patients, echocardiography may be more appropriate, with transoesophageal echocardiography (TEE) offering superior evaluation compared with TTE, which is limited beyond the mid-ascending aorta.

Clinical factors associated with higher rates of aortic expansion and adverse events in uncomplicated type B dissections include younger age (<60 years), White ethnicity, Marfan syndrome and baseline heart rate >60 bpm. Radiological risk factors for complications include aortic diameter ≥4 cm, patent or partially thrombosed false lumen, false lumen diameter ≥2.2 cm, large proximal entry tear ≥1 cm and tears on the inner curvature of the aorta [10].

In this patient, urgent CTA confirmed a Stanford Type B dissection with the entry tear just distal to the left subclavian artery (Fig. 2), extending caudally to the common iliac arteries (Fig. 3). The entry tear measured 0.7 cm, below the radiological high-risk threshold. However, the true lumen was smaller than the patent false lumen (Fig. 4), conferring elevated risk. The patient was younger than 60 years and had persistent tachycardia above 60 bpm, both of which are recognised predictors of progression.

Figure 2

Figure 2

Computed tomography aortogram showing entry tear just distal to the left subclavian artery. A = posterior; L = left; P = posterior; R = right.

Figure 3

Figure 3

Tear extending caudally to common iliac arteries. H = head; LP = left posterior; F = foot; RA = right anterior.

Figure 4

Figure 4

True lumen is smaller than the false lumen. H = head; PL = posterior left; F = foot; AR = anterior right.

For uncomplicated Type B dissection, guideline consensus supports OMT, especially blood pressure and heart rate control, targeting systolic blood pressure <120 mmHg and a heart rate <60 bpm [11]. For patients with high-risk features, the role of surgical or endovascular intervention is still debated. Trials such as ADSORB have demonstrated favourable morphological outcomes with TEVAR, while INSTEAD-XL showed that prophylactic TEVAR delayed disease progression with acceptable perioperative safety [11]. Guidelines from the European Association for Cardio-Thoracic Surgery (EACTS) and STS highlight TEVAR’s low perioperative mortality and complications, suggesting its consideration in anatomically suitable patients with high-risk features [11].

Despite her chronological age of 59 years, Comprehensive Geriatric Assessment identified the patient as mildly frail (Clinical Frailty Score 5), with impairment in higher-order instrumental activities of daily living. Frailty independently increases the risk of postoperative complications, geriatric syndromes such as delirium and deconditioning, and complex discharge planning [12]. In elective vascular surgery, frail patients have been shown to experience significantly higher postoperative dependence, non-home discharge, or 30-day mortality, with frailty conferring more than a 12-fold increase in adverse outcomes, independent of the procedure type [13].

This patient’s cardiorespiratory comorbidities compounded her risk profile, including asthma with suboptimal long-term symptom control, OSA and HFpEF. The American College of Surgeons Surgical Risk Calculator [14] estimated higher perioperative risks (this patient vs. average) including: serious complications (25.8% vs. 19.9%), reoperation (13.7% vs. 7.8%) and discharge to institutional care (35.6% vs. 13.9%). Collectively, these factors suggested that prophylactic TEVAR, despite addressing high-risk dissection features, might expose her to greater harm than conservative management.

Given this complexity, a structured SDM consultation was conducted. The patient and family were presented with the risks and benefits of surveillance versus prophylactic TEVAR, alongside realistic expectations for functional recovery and postoperative complications. Ultimately, a consensus was reached to pursue surveillance, with intervention reserved for clinical or radiological progression.

SDM is particularly valuable in perioperative medicine, in which patients often face difficult trade-offs between potential survival benefits and high complication risk. With ageing populations and an increasing burden of long-term health conditions, the number of high-risk surgical candidates is increasing. Notably, up to one-third of these patients develop significant perioperative complications, frequently resulting in lasting functional decline [15].

SDM integrates clinician expertise with patient preferences to guide treatment, and evidence consistently shows that patients want greater involvement in these choices. Those engaged in SDM report stronger communication, less decisional regret and better adherence [16, 17]. In perioperative settings, SDM may also reduce surgical uptake, as patients – often more risk-averse than clinicians – frequently prefer conservative options once informed of risks and uncertainties [16]. This shift may yield system-level benefits, including reduced costs associated with complex complications. Importantly, systematic reviews show that SDM does not prolong consultations, reinforcing its practicality for routine care [18].

This case highlights the importance of balancing anatomical and clinical risk factors against patient frailty and comorbidities when managing high-risk, uncomplicated Type B aortic dissections. SDM ensured that the chosen pathway aligned both with evidence and with the patient’s values, underscoring its essential role in perioperative practice.

Declarations and conflicts of interest