Patient-specific ascending aortic intervention criteria.

OBJECTIVES: Ascending aortic aneurysms pose a different risk to each patient. We aim to provide personalized risk stratification for such patients based on sex, age, body surface area and aneurysm location (root versus ascending). METHODS: Root and ascending diameters, and adverse aortic events (dissection, rupture, death) of ascending thoracic aortic aneurysm patients were analysed. Aortic diameter was placed in context vis-a-vis the normal distribution in the general population with similar sex, age and body surface area, by conversion to z scores. These were correlated of major adverse aortic events, producing risk curves with 'hinge points' of steep risk, constructed separately for the aortic root and mid-ascending aorta. RESULTS: A total of 1162 patients were included. Risk curves unveiled generalized thresholds of z = 4 for the aortic root and z = 5 for the mid-ascending aorta. These correspond to individualized thresholds of less than the standard criterion of 5.5 cm in the vast majority of patients. Indicative results include a 75-year-old typical male with 2.1 m2 body surface area, who was found to be at increased risk of adverse events if root diameter exceeds 5.15 cm, or mid ascending exceeds 5.27 cm. An automated calculator is presented, which identifies patients at high risk of adverse events based on sex, age, height, weight, and root and ascending size. CONCLUSIONS: This analysis exploits a large sample of aneurysmal patients, demographic features of the general population, pre-dissection diameter, discrimination of root and supracoronary segments, and statistical tools to extract thresholds of increased risk tailor-made for each patient.

Midterm follow-up of composite graft replacement of the aortic root (30-year experience)-remarkably safe, effective, and durable.

Objectives: Contemporary operative choices for aortic root disease include aortic root replacement (ARR) and a variety of valve-sparing and aortic root-repair procedures. We evaluate ultra-long-term outcomes of ARR, focusing on survival, freedom from late reoperation, and adverse events. Methods: Prospectively kept records were used to accomplish long-term follow-up of patients who underwent ARR (4-pronged Yale survival assessment paradigm). Results: Between 1990 and 2020, 564 patients underwent ARR (mean 56 years, 84% male). A modified Cabrol procedure (Dacron coronary graft) was employed in 9.0% (51/564) and concomitant coronary artery bypass grafting in 9.4% (53/564). There were 12.8% (72/564) urgent/emergent and 7.4% (42/564) redo procedures. Operative mortality occurred in 12 patients (2.1%) overall, or 1.4% (8/554) of nondissection and 1.3% (6/468) of elective first-time operations. Six of the 12 deaths presented with acute type A dissection, urgent operation, or reoperative states. Operative mortality dropped to 0.6% during the past 10 years. In total, 11 patients developed endocarditis. Stroke occurred in 11 of 564 patients (2.0%), 4 of whom had presented with type A dissection. Late events included bleeding in 2.8% (16/564), thromboembolism in 1.4% (8/564), and reoperation of the root in 5 of 564 (0.9%) at 15 years and more distal aortic segments in 16/564 (2.8%). Survival was no different from age/sex-matched controls. Conclusions: This ultra-long-term experience finds ARR to be extraordinarily safe, effective, and durable, with minimal long-term bleeding, thromboembolism, or graft failure. This experience provides a standard of durability for ARR against which ultra-long-term outcomes with alternate procedures (valve-sparing, Ross, other) may be compared.

Safety of cerebrospinal fluid drainage in descending and thoracoabdominal aortic replacement surgery.

Background: Spinal cord injury (SCI) remains a significant morbidity of surgical repair of descending thoracic aortic aneurysms (DTAA) and thoracoabdominal aortic aneurysms (TAAA). We present our 17-year experience with cerebrospinal fluid drainage (CSFD) as a protective strategy during open surgical repair of descending and thoracoabdominal aortic disease. Methods: We conducted a retrospective chart review of 132 patients who underwent open surgical repair of DTAA and TAAA and dissections with concurrent use of CSFD for spinal cord protection. Information regarding survival, postoperative course, and complications related to CSFD use were extracted from electronic health records (EHR) and analyzed. Results: Mean patient age was 65.4±13.0 years, and 82 (62.1%) were male. A CSFD was successfully inserted in all patients. The mean hospital length of stay after surgery was 12.2±11.2 days, and in-hospital mortality was 7.6%. Postoperative transient paresis was observed in 5 patients (3.8%), and permanent paraplegia was seen in 4 (3.0%). CSFD related complications were reported in 25 patients (19%). Complications included persistent cerebrospinal fluid (CSF) leakage, blood-tinged CSF (with subdural hematoma reported in 3 patients) and spinal cutaneous fistula in 9 (7%), 14 (11%), and 1 (1%), respectively. Long term survival was 50.9% at 15 years. Conclusions: CSFD is associated with minor complications, without major sequalae. It is a safe practice and likely contributes innocuously to decreased SCI in patients undergoing open repair of DTAA and TAAA.

Full calcium jacket: Conservative management of a traumatic aortic injury.

We describe the case of an elderly male patient who presented with a proximal descending aortic aneurysm after a motorcycle accident in 1977. We concluded that the aorta had been transected at that time. In a rather unconventional manner, the aneurysm developed a circumferential layer of calcification that provided mechanical stability and likely prevented further degeneration. We chose not to pursue surgical intervention at the late stage of his presentation. The patient has been followed up for a period of 30 years, with no change in the size and shape of the now completely calcified aneurysm.

Aortic Size at the Time of Type A and Type B Dissections.

BACKGROUND: Aortic diameter at time of dissection remains an indispensable risk-determining characteristic for prophylactic repair of thoracic aortic aneurysms. Histograms of aortic size at the time of dissection have the potential to shed more light on this relationship. METHODS: Size of the thoracic aorta at the time of dissection was determined from imaging of 407 naturally occurring, acute, flap-type ascending or descending aortic dissections treated at 1 institution (1990-2022). Histograms were constructed to depict aortic size at the time of dissection. Data were analyzed by logistic regression. RESULTS: There were 170 (69.11%) of 246 type A dissections (median, 5.07 cm; interquartile range, 4.60-5.67 cm) and 130 (80.75%) of 161 type B dissections (median, 4.2 cm; interquartile range, 3.60-4.87 cm) that occurred at diameters <5.5 cm. By unadjusted regression, factors associated with significantly increased odds of type A dissection at diameters <5.5 cm were female sex (odds ratio [OR], 2.06; P = .023), hypertension (OR, 1.82; P = .036), and smoking (OR, 1.92; P = .029). Patients with bicuspid aortic valve had significantly decreased odds of type A dissection at diameters <5.5 cm (OR, 0.3; P = .047). The recent "left shift" to 5.0 cm in the criterion for ascending aortic intervention could prevent an additional 29.3% of type A dissections. CONCLUSIONS: Aortic diameter at the time of type A dissection is consistent with the new guidelines that recommend surgical intervention at 5.0 cm. Type B dissection occurs at small sizes and cannot be prevented with a size criterion.

Extended law of laplace for measurement of the cloverleaf anatomy of the aortic root.

The cross-sectional shape of the aortic root is cloverleaf, not circular, raising controversy regarding how best to measure its radiographic "diameter" for aortic event prediction. We mathematically extended the law of Laplace to estimate aortic wall stress within this cloverleaf region, simultaneously identifying a new metric of aortic root dimension that can be applied to clinical measurement of the aortic root and sinuses of Valsalva on clinical computerized tomographic scans. Enforcing equilibrium between blood pressure and wall stress, finite element computations were performed to evaluate the mathematical derivation. The resulting Laplace diameter was compared with existing methods of aortic root measurement across four patient groups: non-syndromic aneurysm, bicuspid aortic valve, Marfan syndrome, and non-dilated root patients (total 106 patients, 62 M, 44 F). (1) Wall stress: Mean wall stress at the depth of the sinuses followed this equation: Wall stress = BP × Circumscribing circle diameter/(2 × Aortic wall thickness). Therefore, the diameter of the circle enclosing the root cloverleaf, that is, twice the distance between the center, where the sinus-to-commissure lines coincide, and the depth of the sinuses, may replace diameter in the Laplace relation for a cloverleaf cross-section (or any shaped cross-section with two or more planes of symmetry). This mathematically derived result was verified by computational finite element analyses. (2) Diameters: CT scan measurements showed a significant difference between this new metric, the Laplace diameter, and the sinus-to-commissure, mid-sinus-to-mid-sinus, and coronal measurements in all four groups (p-value < 0.05). The average Laplace diameter measurements differed significantly from the other measurements in all patient groups. Among the various possible measurements within the aortic root, the diameter of the circumscribing circle, enclosing the cloverleaf, represents the diameter most closely related to wall stress. This diameter is larger than the other measurements, indicating an underestimation of wall stress by prior measurements, and otherwise provides an unbiased, convenient, consistent, physics-based measurement for clinical use. "Diameter" applies to circles. Our mathematical derivation of an extension of the law of Laplace, from circular to cloverleaf cross-sectional geometries of the aortic root, has implications for measurement of aortic root "diameter." The suggested method is as follows: (1) the "center" of the aortic root is identified by drawing three sinus-to-commissure lines. The intersection of these three lines identifies the "center" of the cloverleaf. (2) The largest radius from this center point to any of the sinuses is identified as the "radius" of the aortic root. (3) This radius is doubled to give the "diameter" of the aortic root. We find that this diameter best corresponds to maximal wall stress in the aortic root. Please note that this diameter defines the smallest circle that completely encloses the cloverleaf shape, touching the depths of all three sinuses.

Bicuspid aortopathy does not require earlier surgical intervention.

OBJECTIVES: Guidelines for surgical correction of patients with ascending thoracic aortic aneurysm (ATAA) with a bicuspid aortic valve (BAV) have oscillated over the years. In this study, we outline the natural history of the ascending aorta in patients with BAV and trileaflet aortic valve (TAV) ATAA followed over time, to ascertain if their behavior differs and to determine if a different threshold for intervention is required. METHODS: Aortic diameters and long-term complications (ie, adverse aortic events) of 2428 patients (554 BAV and 1874 TAV) with ATAA before operative repair were reviewed. Growth rates, yearly complication rates, event-free survival, and risk of complications as a function of aortic size were calculated. Long-term follow-up and precise cause of death granularity was achieved via a comprehensive 6-pronged approach. RESULTS: Aortic growth rate in patients with BAV vs TAV ATAA was 0.20 and 0.17 cm/year, respectively (P = .009), with the rate increasing with increasing aortic size. Yearly adverse aortic events rates increased with ATAA size and were lower for patients with BAV. The relative risk of adverse aortic events exhibited an exponential increase with aortic diameter. Patients with BAV had a lower all-cause and ascending aorta-specific adverse aortic events hazard. Age-adjusted 10-year event-free survival was significantly better for patients with BAV, and BAV emerged as a protective factor against type A dissection, rupture, and ascending aortic death. CONCLUSIONS: The threshold for surgical repair of ascending aneurysm with BAV should not differ from that of TAV. Prophylactic surgery should be considered at 5.0 cm for patients with TAV (and BAV) at expert centers.

Fate of the unoperated ascending thoracic aortic aneurysm: three-decade experience from the Aortic Institute at Yale University.

AIMS: This study aims to outline the 'true' natural history of ascending thoracic aortic aneurysm (ATAA) based on a cohort of patients not undergoing surgical intervention. METHODS AND RESULTS: The outcomes, risk factors, and growth rates of 964 unoperated ATAA patients were investigated, over a median follow-up of 7.9 (maximum of 34) years. The primary endpoint was adverse aortic events (AAE), including dissection, rupture, and aortic death. At aortic sizes of 3.5-3.9, 4.0-4.4, 4.5-4.9, 5.0-5.4, 5.5-5.9, and ≥6.0 cm, the average yearly risk of AAE was 0.2%, 0.2%, 0.3%, 1.4%, 2.0%, and 3.5%, respectively (P < 0.001), and the 10-year survival free from AAE was 97.8%, 98.2%, 97.3%, 84.6%, 80.4%, and 70.9%, respectively (P < 0.001). The risk of AAE was relatively flat until 5 cm of aortic size, at which it began to increase rapidly (P for non-linearity <0.001). The mean annual growth rate was estimated to be 0.10 ± 0.01 cm/year. Ascending thoracic aortic aneurysms grew in a very slow manner, and aortic growth over 0.2 cm/year was rarely seen. Multivariable Cox regression identified aortic size [hazard ratio (HR): 1.78, 95% confidence interval (CI): 1.50-2.11, P < 0.001] and age (HR: 1.02, 95% CI: 1.00-1.05, P = 0.015) as significant independent risk factors for AAE. Interestingly, hyperlipidemia (HR: 0.46, 95% CI: 0.23-0.91, P = 0.025) was found to be a significant protective factor for AAE in univariable Cox regression. CONCLUSION: An aortic size of 5 cm, rather than 5.5 cm, may be a more appropriate intervention criterion for prophylactic ATAA repair. Aortic growth may not be an applicable indicator for intervention.

Cerebrospinal Fluid Drainage for Prevention of Spinal Cord Ischemia in Thoracic Endovascular Aortic Surgery-Pros and Cons.

Thoracic endovascular aortic repair (TEVAR) carries a risk of spinal cord ischemia (SCI) which exerts a devastating impact on patient's quality of life and life expectancy. Although routine prophylactic cerebrospinal fluid (CSF) drainage is not unequivocally supported by current data, several studies have demonstrated favorable outcomes. Patients at high risk for SCI following TEVAR likely will benefit from prophylactic CSF drains. However, the intervention is not risk free, and thorough risk/benefit analysis should be individualized to each patient.

Rapid growth of thoracic aortic aneurysm: Reality or myth?

OBJECTIVES: The American Association for Thoracic Surgery 2010 guidelines stipulate that rapid growth of the aorta (>3 mm/y) is an indication for prophylactic surgical intervention. Because of the many potential sources of error in aortic measurement (including measurement variability and comparison of noncorresponding segments), we explored whether rapid aortic growth was a reality or a falsehood. METHODS: Among 2781 patients with aortic disease who were treated over 3 decades, we examined aortic growth rate in 811 patients with at least 2 aortic images taken at least 2 years apart. We identified 42 ascending and 27 descending patients with putative rapid aortic growth. A team of experienced clinicians reread the source images. RESULTS: Among the 42 ascending patients with putative rapid aortic growth, rapid growth was confirmed in 12 and refuted in 11 (19 images nonretrievable). Among the 27 descending patients, rapid growth was confirmed in 6 and refuted in 4 (17 images nonretrievable). We calculated lower, middle, and highest possible rapid growth rates by prorating positivity rates for nonretrievable scans. Lowest, middle, and highest possible rates of rapid growth were 2.7%, 4.7%, and 6.9% for ascending aorta, and 1.6%, 4.3%, and 7.3% for descending aneurysms, respectively. Middle rates are considered most accurately reflective. Of the patients with confirmed rapid growth, 3 of 4 inoperable patients succumbed to their aorta. Twenty-three patients underwent prompt surgery, with 22 survivors. For the rapidly growing aortas, operative, pathologic, and genetic findings are reported. CONCLUSIONS: Although not a falsehood, rapid growth is uncommon for the ascending and descending aorta. Many putative cases are reflective of measurement error. Attention to potential sources of measurement error is key. VIDEO ABSTRACT.

Engineering analysis of aortic wall stress and root dilatation in the V-shape surgery for treatment of ascending aortic aneurysms.

OBJECTIVES: The study objective was to evaluate the aortic wall stress and root dilatation before and after the novel V-shape surgery for the treatment of ascending aortic aneurysms and root ectasia. METHODS: Clinical cardiac computed tomography images were obtained for 14 patients [median age, 65 years (range, 33-78); 10 (71%) males] who underwent the V-shape surgery. For 10 of the 14 patients, the computed tomography images of the whole aorta pre- and post-surgery were available, and finite element simulations were performed to obtain the stress distributions of the aortic wall at pre- and post-surgery states. For 6 of the 14 patients, the computed tomography images of the aortic root were available at 2 follow-up time points post-surgery (Post 1, within 4 months after surgery and Post 2, about 20-52 months from Post 1). We analysed the root dilatation post-surgery using change of the effective diameter of the root at the two time points and investigated the relationship between root wall stress and root dilatation. RESULTS: The mean and peak max-principal stresses of the aortic root exhibit a significant reduction, P=0.002 between pre- and post-surgery for both root mean stress (median among the 10 patients presurgery, 285.46 kPa; post-surgery, 199.46 kPa) and root peak stress (median presurgery, 466.66 kPa; post-surgery, 342.40 kPa). The mean and peak max-principal stresses of the ascending aorta also decrease significantly from pre- to post-surgery, with P=0.004 for the mean value (median presurgery, 296.48 kPa; post-surgery, 183.87 kPa), and P=0.002 for the peak value (median presurgery, 449.73 kPa; post-surgery, 282.89 kPa), respectively. The aortic root diameter after the surgery has an average dilatation of 5.01% in total and 2.15%/year. Larger root stress results in larger root dilatation. CONCLUSIONS: This study marks the first biomechanical analysis of the novel V-shape surgery. The study has demonstrated significant reduction in wall stress of the aortic root repaired by the surgery. The root was able to dilate mildly post-surgery. Wall stress could be a critical factor for the dilatation since larger root stress results in larger root dilatation. The dilated aortic root within 4 years after surgery is still much smaller than that of presurgery.

A novel computational growth framework for biological tissues: Application to growth of aortic root aneurysm repaired by the V-shape surgery.

Ascending aortic aneurysms (AsAA) often include the dilatation of sinotubular junction (STJ) and extend proximally into the aortic root, which usually leads to aortic insufficiency. The novel surgery of the V-shape resection of the noncoronary sinus, for treatment of AsAA with root ectasia, has been shown to be a simpler procedure compared to traditional surgeries. Our previous study showed that the repaired aortic root aneurysms grew after the surgery. In this study, we developed a novel computational growth framework to model the growth of the aortic root repaired by the V-shape surgery. Specifically, the unified-fiber-distribution (UFD) model was applied to describe the hyperelastic deformation of the aortic tissue. A novel kinematic growth evolution law was proposed based on existing observations that the growth rate is linearly dependent on the wall stress. Moreover, we also obtained patient-specific geometries of the repaired aortic root post-surgery at two follow-up time points (Post-1 and Post-2) for 5 patients, based on clinical CT images. The novel computational growth framework was implemented into the Abaqus UMAT user subroutine and applied to model the growth of the aortic root from Post-1 to Post-2. Patient-specific growth parameters were obtained by an optimization procedure. The predicted geometry and stress of the aortic root at Post-2 agree well with the in vivo results. The novel computational growth framework and the optimized growth parameters could be applied to predict the growth of repaired aortic root aneurysms for new patients and to optimize repair strategies for AsAA.

Fate of Preserved Aortic Root Following Acute Type A Aortic Dissection Repair.

We examined the long-term fate of the preserved aortic root after emergent repair of acute Type A aortic dissection. 144 patients (60% males, mean age 60.5 years) underwent supracoronary ascending aortic replacement for acute Type A aortic dissection. Long-term survival, as well as growth, reoperation, and adverse events of the aortic root (rupture, pseudoaneurysm, and persistent dissection) were retrospectively assessed. Operative mortality was 9%, and overall survival at 1, 5, and 10 years was 87.8%, 76.4%, and 64.6%, respectively. Reoperation on the proximal aorta was performed in 16 patients (12.2%) within a median of 2.45 years post-operatively. Indications were severe aortic insufficiency (AI) (n = 6), aortic root pseudoaneurysm (n = 8), pseudoaneurysm with severe AI (n = 1), and persistent dissection with severe AI (n = 1). The aortic root grew at 0.2mm/year (interquartile range 0-0.8). Among survivors (n = 131), 28 patients (21.3%) reached aortic root diameter ≥ 45 mm (mean diameter 47.6 mm, range 45-54 mm). Survival free from proximal aortic reoperation at 1, 5, and 10 years was 96.6%, 94.5%, and 92.2%, respectively. No non-reoperated patient-despite persistent, unoperated enlargement or distortion or pseudoaneurysm of the aortic root-developed free rupture or fistula to a cardiac chamber. Root-sparing ascending aortic replacement for acute Type-A aortic dissection showed satisfactory long-term outcomes with relatively low rates of re-intervention or serious aortic root adverse events despite dilatation and irregularity of aortic root contour. Dense adhesions from prior surgery, proximal aortic suture line, and Teflon felt seem to discourage free rupture or fistulization.

Massive Sternal Osteophyte Compressing Aortic Arch Branch Graft.

We present a dramatic computed tomography scan demonstrating compression of a brachiocephalic graft by a massive sternal osteophyte, coming to light many years after aortic arch replacement surgery.

Safety of perioperative cerebrospinal fluid drain as a protective strategy during descending and thoracoabdominal open aortic repair.

OBJECTIVE: We present our experience with routine application of the cerebrospinal fluid (CSF) drain (CSFD) during open aortic repair. METHODS: We retrospectively reviewed 100 patients with descending thoracic aortic aneurysm (DTAA) or thoracoabdominal aortic aneurysm (TAAA) or who underwent CSFD insertion before open repair between 2006 and 2017. All CSFDs were inserted by the cardiovascular anesthesia team. The goal was to keep intracranial pressure <10 mm Hg during the surgical procedure by draining CSF at a rate of 20 to 30 mL/h. Postoperatively, CSFD was set to maintain the lumbar pressure <10 mm Hg to reduce the risk of postoperative paraplegia. CSFD was part of our standard cord protection regimen. RESULTS: The mean patient age was 65.4 ± 11.7 years, and 60 (60%) were male. A CSFD was successfully inserted in all patients. The mean hospital length of stay was 11.9 ± 11.8 days, and hospital mortality was 6%. Postoperative transient paresis was observed in 4 patients (4%), and permanent paraplegia was seen in 2 (2%). CSFD-related complications were reported in 14 patients (14%). Complications included persistent CSF leakage and blood-tinged CSF with and without intracranial hemorrhage and spinal cutaneous fistula in 7 (7%), 9 (9%), and 1 (1%), respectively. Long-term survival was excellent (68.4% at 10 years). CONCLUSIONS: CSFD is a safe practice when applied routinely as an adjunct strategy to prevent paraplegia in surgical management of DTAA and TAAA. We feel that this contributed to good early and late clinical results.

Increased Virulence of Descending Thoracic and Thoracoabdominal Aortic Aneurysms in Women.

BACKGROUND: This study evaluates sex differences in the natural history of descending thoracic and thoracoabdominal aortic aneurysms (DTTAAs). METHODS: In all, 907 patients with descending thoracic and thoracoabdominal aortic sizes greater than 3 cm were retrospectively reviewed. Growth rate estimates were performed utilizing an instrumental variables approach. Yearly complication rates as a function of aortic size were computed. RESULTS: There were 615 men (67.8%) and 292 women (32.2%) treated between 1990 and 2018, with mean aortic diameters of 4.1 ± 1.4 cm and 4.8 ± 1.6 cm, respectively (P < .001). The mean growth rate of DTTAAs was 0.17 cm per year in men and 0.25 cm per year in women (P < .001), increasing with increasing aneurysm size. Dissection, rupture, or aortic death or the combination of the three occurred at double the rate for women compared with men (5.8% vs 2.3% per year for the combined endpoint). Diameter of DTTAA greater than 5 cm was associated with 26.3% (male) and 33.1% (female) average yearly rates of the composite endpoint of rupture, dissection, and death (P < .05). The probability of fatal complications (rupture and death) increased sharply at 5.75 cm in both sexes. Between 4.5 and 5.75 cm, there was another hinge-point of higher probability of fatal complications among women. CONCLUSIONS: Women diagnosed with DTTAA fare worse. Faster aneurysm growth and higher rates of dissection, rupture, and aortic death are apparent among women. Current guidelines recommend surgical intervention at 5.5 to 6 cm for DTTAAs without sex considerations. Our findings suggest that increased virulence of DTTAA in women may indicate surgery at a somewhat smaller diameter.