Early three-dimensional growth in uncomplicated type B aortic dissection is associated with long-term outcomes

OBJECTIVE

Late adverse events (LAEs) are common among initially uncomplicated type B aortic dissection (uTBAD); however, identifying those patients at highest risk of LAEs remains a significant challenge. Early false lumen (FL) growth has been suggested to increase risk, but confident determination of growth is often hampered by error in two-dimensional clinical measurements. Semi-automated three-dimensional (3D) mapping of aortic growth, such as by vascular deformation mapping (VDM), can potentially overcome this limitation using computed tomography angiograms (CTA). We hypothesized that FL growth in the early pre-dissection phase by VDM can accurately predict LAEs.

METHODS

We performed a two-center retrospective study of patients with uTBAD, with paired CTAs in the acute (1-14 days) and subacute/early chronic (1-6 months) periods. VDM analysis was used to map 3D growth. Standard clinical CT measures (ie, aortic diameters, tear characteristics) were also collected. Multivariate analysis was conducted using a decision tree and Cox proportional hazards model. LAEs were defined as aneurysmal FL (>55 mm); rapid growth (>5 mm within 6 months); aorta-specific mortality, rupture, or re-dissection.

RESULTS

A total of 107 (69% male) patients with uTBAD initially met inclusion criteria with a median follow-up of 7.3 years (interquartile range [IQR], 4.7-9.9 years). LAEs occurred in 72 patients (67%) at 2.5 years (IQR, 0.7-4.8 years) after the initial event. A multivariate decision tree model identified VDM growth (>2.1 mm) and baseline diameter (>42.7 mm) as optimal predictors of LAEs (area under the receiver operating characteristic curve = 0.94), achieving an 87% accuracy (sensitivity of 93%, specificity of 76%) after leave-one-out validation. Guideline reported high-risk features were not significantly different between groups.

CONCLUSIONS

Early growth of the FL in uTBAD was the best tested indicator for LAEs and improves upon the current gold-standard of baseline diameter in selecting patients for early prophylactic thoracic endovascular aortic repair.

Clinical Imaging and Innovations in Aortic Aneurysm and Dissection

Imaging plays a central role in the management of patients with aortic disease. Such imaging can be made particularly complex by changing terminology and definitions, overlapping pathologies, and unfamiliarity with evolving endovascular treatment approaches. This article will review basic principles of aortic imaging that can be applied across a variety of settings and pathologies, with a description of key best practices and potential pitfalls for image acquisition, diagnostic assessment, and reporting. Additionally, the topic of imaging in the setting of endovascular aortic repair will be addressed, as well as a variety of imaging-related diagnostic challenges in the setting of chronic aortic dissection, including surgically repaired type A and uncomplicated type B dissections. Finally, recent developments in advanced aortic imaging will be highlighted with descriptions of several areas of promising research that may yield significant advances in imaging of aortic disease.

Distal anastomosis new entry tear in acute type A aortic dissection: A risk factor for distal aortic reoperation

Objective

To identify predictive factors for the occurrence of a distal anastomosis new entry tear (DANE) in patients who underwent hemiarch replacement after acute type A aortic dissection (ATAAD) and examine the association of DANE with distal aortic reoperation.

Methods

Between 1996 and March 2021, 434 patients underwent hemiarch replacement for DeBakey I ATAAD, of whom 327 patients had adequate postoperative imaging. Based on the presence of DANE on postoperative computed tomography angiography, patients were divided into the DANE group (n = 81) and the no-DANE group (n = 246). Primary outcomes were the cumulative incidence of distal aortic reoperation and the risk factors for DANE.

Results

Most perioperative characteristics and outcomes, including age, sex, malperfusion syndromes, aortic diameters, and operative mortality were similar in the 2 groups. Using death as a competing factor, the 10-year cumulative incidence of distal aortic reoperation was higher in the DANE group compared to the no-DANE group (30% vs 12%; P = .0001). The hazard ratio for DANE in distal reoperations was 2.28 (P = .005). A multivariable regression model showed that having an aortic surgeon was protective against DANE compared to having a nonaortic surgeon (odds ratio [OR], 0.29; P = .05) and identified branch dissection (OR, 2.42; P = .002) as a risk factor for the occurrence of DANE. Connective tissue disease and large-bore suture (4-0 vs 5-0) were not associated with DANE.

Conclusions

Optimizing surgical techniques to prevent DANE in ATAAD repair may prevent the need for reoperation on the distal aorta in DeBakey type I ATAAD.

Assessing the impact of 3D image segmentation workshops on anatomical education and image interpretation: A prospective pilot study

Three-dimensional (3D) segmentation, a process involving digitally marking anatomical structures on cross-sectional images such as computed tomography (CT), and 3D printing (3DP) are being increasingly utilized in medical education. Exposure to this technology within medical schools and hospitals remains limited in the United Kingdom. M3dicube UK, a national medical student, and junior doctor-led 3DP interest group piloted a 3D image segmentation workshop to gauge the impact of incorporating 3D segmentation technology on anatomical education. The workshop, piloted with medical students and doctors within the United Kingdom between September 2020 and 2021, introduced participants to 3D segmentation and offered practical experience segmenting anatomical models. Thirty-three participants were recruited, with 33 pre-workshop and 24 post-workshop surveys completed. Two-tailed t-tests were used to compare mean scores. From pre- to post-workshop, increases were noted in participants' confidence in interpreting CT scans (2.36 to 3.13, p = 0.010) and interacting with 3D printing technology (2.15 to 3.33, p = 0.00053), perceived utility of creating 3D models to aid image interpretation (4.18 to 4.45, p = 0.0027), improved anatomical understanding (4.2 to 4.7, p = 0.0018), and utility in medical education (4.45 to 4.79, p = 0.077). This pilot study provides early evidence of the utility of exposing medical students and healthcare professionals in the United Kingdom to 3D segmentation as part of their anatomical education, with additional benefit in imaging interpretation ability.

Hip Arthroscopy in Patients With Generalized Joint Hypermobility Yields Successful Outcomes: A Systematic Review

PURPOSE

To evaluate the outcomes of hip arthroscopy in patients with generalized joint hypermobility (GJH).

METHODS

A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses. An electronic record search was performed in PubMed, Web of Science, Cochrane Library, and Embase. A 2-stage title/abstract and full-text screening was performed using the following inclusion criteria: (1) observational studies, cohort studies, and randomized controlled trials; (2) describing more than 5 patients with a mean age over 18 years and GJH; (3) undergoing arthroscopy of the hip; (4) reporting patient-reported outcome measures (PROMs), return to sport, or complications/reoperations; and (5) published in English.

RESULTS

Of the 517 articles identified, 10 studies meeting all selection criteria were included. Included studies report significant improvements in a range of different functional and pain-based PROMs. Most patients (25.0%-97.0%) in each study achieved a clinically important improvement postoperatively in at least 1 PROM. No complications were described in any of the 4 studies reporting this metric. One study each found an association between GJH and an increased risk of postoperative deep gluteal syndrome and iliopsoas tendinitis. The rate of revision arthroscopy ranged from 0% to 11.4%, and only 2 patients in a single study of 11 hips required conversion to total hip arthroplasty. No statistically significant differences were reported between patients with and without GJH with respect to any of the described outcomes.

CONCLUSIONS

Patients with GJH may achieve good outcomes following hip arthroscopy with respect to PROMs, perioperative complications, reoperation, and return to sport. With effective labral repair and capsular closure, outcomes achieved in patients with GJH are comparable to those reported in patients without hypermobility.

LEVEL OF EVIDENCE

Level IV, systematic review of level III to IV studies.

Baseline Diameter Does Not Predict Growth Rate in a Presurgical Ascending Thoracic Aortic Aneurysm Population

BACKGROUND

Patients with ascending thoracic aortic aneurysm are recommended to undergo routine imaging surveillance. Although maximal diameter is the primary metric of disease severity, recent American College of Cardiology/American Heart Association guidelines emphasize the importance of aortic growth in determining surgical candidacy and risk. As diameter increases, it is assumed that aortic growth rate accelerates because of increased wall tension; however, this relationship is poorly studied. We aim to investigate the relationship between ascending thoracic aortic aneurysm diameter and growth rate using vascular deformation mapping, a validated technique for 3-dimensional growth mapping with submillimeter accuracy.

METHODS AND RESULTS

We retrospectively identified adult patients with ascending aortic dilation (≥4.0 cm) and serial gated computed tomography angiograms separated by ≥2 years, excluding confirmed heritable thoracic aortic disease. Ascending growth rate was defined as 90th percentile radial wall deformation by vascular deformation mapping. Maximal diameter measurements were derived from the baseline computed tomography angiogram, and aortic length and body size-adjusted indexes were calculated. Among 258 included patients (63.2% men; age of 63 years [interquartile range, 55-69 years]), mean±SD baseline diameter was 46.3±3.6 mm and median growth rate was 0.21 mm/year (interquartile range, 0.13-0.38 mm/year). No correlation was noted between growth rate and baseline diameter (r=0.02, P=0.74) or other aortic size metrics. On multivariate analysis, age was independently predictive of growth rate (β=-0.007, P=0.021), alongside weight (β=0.003, P=0.016) and the presence of moderate or severe aortic valve insufficiency (β=0.146, P=0.049).

CONCLUSIONS

Maximal aortic diameter is not predictive of aortic growth rate, in this contemporary cohort of patients with sizes under current surgical thresholds (<55 mm).

Three-dimensional assessment of ascending aortic stiffness, motion, and growth in ascending thoracic aortic aneurysm

Aims

Aortic wall stiffening in ascending thoracic aortic aneurysm (aTAA) is common. However, the spatial and temporal relationships between stiffness, aortic size, and growth in aTAA remain unclear.

Methods and results

In this single-centre retrospective study, we utilized vascular deformation mapping to extract multi-directional aortic motion, aortic distensibility, and aortic growth in a multi-planar fashion from multi-phasic ECG-gated computed tomography angiograms. Aortic displacement and stiffness metrics were compared between patients with sporadic ascending aortic dilation (Dilated), individuals without thoracic aortic dilation, and patients with Marfan syndrome. A total of 96 patients were included. Total and axial aortic root motion was significantly decreased in the Dilated group (n = 49) compared with the Non-dilated group (n = 38) and Marfan group (n = 16). Aortic distensibility was significantly lower in the Dilated group compared with the Non-dilated group and exhibited a more diffuse pattern of stiffening compared with the Marfan group in which stiffening was localized to the root. In Dilated group, aortic distensibility was moderately and positively associated with aortic growth rate (R = 0.34, P = 0.02). The moderate-to-strong association between age and aortic stiffness in non-dilated segments was either significantly blunted or absent in dilated segments.

Conclusion

Vascular deformation mapping provides multi-level stiffness assessments of the ascending aorta using multi-phasic computed tomography angiography. Ascending aortic stiffening is a spatially heterogeneous process with stiffening tending to increase with degree of regional dilation and age, whereas lower stiffness was associated with faster growth of the mid-ascending aorta in those with sporadic aTAA.