Cine-Computed Tomography for the Evaluation of Prosthetic Heart Valve Function.

BACKGROUND: After aortic valve replacement (AVR), suspected prosthetic valve dysfunction (mechanical or biological) may arise based on echocardiographic transvalvular velocities and gradients, leading to reoperative surgical intervention being considered. Our experience has found that 4-dimensional (space and time) image reconstruction of ECG-gated computed tomography, termed cine-CT, may be helpful in such cases. We review and illustrate our experience. METHODS: Twenty-seven AVR patients operated previously by a single surgeon (who performs >100 AVRs/year) were referred for repeat evaluation of suspected aortic stenosis (AS) based on elevated transvalvular velocities and gradients. The patients were fully evaluated by cine-CT. RESULTS: In all but 2 cases, the cine-CT strikingly and visually confirmed normal leaflet function and excursion, with no valve thrombosis, restriction by pannus, or obstruction by clot. In only 2 cases did cine-CT reveal decreased mechanical valve leaflet excursion. Repeat surgery was required in only 1 case while all other patients continued clinically without cardiac events. CONCLUSIONS: Echocardiography is an extraordinarily useful tool for the evaluation of prosthetic valve function. Increased pressure recovery beyond the valve and other factors may occasionally lead to exaggerated gradients. Cine-CT is emerging as an extremely valuable tool for further evaluation of suspected prosthetic valve AS. Our experience has been extremely helpful, as is shown in the dramatically reassuring images.

Fate of preserved bicuspid valves at time of ascending aortic aneurysmectomy.

BACKGROUND: The fate of the spared bicuspid aortic valve in patients undergoing ascending aortic aneurysm surgery is relatively unknown. Our institutional policy has been to replace all aortic valves with significant abnormalities, as evidenced by intraoperative transesophageal echocardiography or direct visual inspection. In this study, we elaborate our experience regarding the long-term fate of preserved bicuspid aortic valves after ascending aortic aneurysm extirpation. MATERIALS AND METHODS: From 2000 to 2018, 407 consecutive ascending aortic aneurysm patients with concomitant bicuspid aortic valves underwent surgery by a single surgeon at our institution. Among these, 23 (5.65%) patients did not have their valve replaced, forming the study group. Postoperative and preoperative echocardiograms were compared to determine changes in valve function. RESULTS: Follow-up was complete in 100% of patients. The average time between preoperative and postoperative echocardiograms was 4.50 ± 4.09 years (0.19-15.63). Aortic stenosis or regurgitation changed from none to mild in 5 (21.7%) of patients, with an average echocardiographic interval follow-up of 3.08 years, and from none to severe in 2 (8.7%), with an interval of 11.7 years. One patient required reoperation, including aortic valve replacement, during follow-up. CONCLUSION: Bicuspid aortic valves free of aortic stenosis or insufficiency before surgery and "healthy" appearing at surgery can safely be preserved.

Routine anterior spinal artery visualization prior to descending and thoracoabdominal aneurysm repair: High detection success.

BACKGROUND: Paraplegia is adevastating complication of open descending (DTAA) and thoracoabdominal aortic aneurysm (TAAA) repair. Despite major advances in imaging and surgical techniques, paraplegia continues to be problematic. We present our experience with routine application of enhanced imaging techniques to detect the anterior spinal artery (ASA) before DTAA and TAAA repair. METHODS: We retrospectively reviewed 177 patients with DTAA and TAAA who underwent imaging to detect the ASA before open surgical repair. High definition CT angiography (CTA) and dual energy CT scanning (DECT) were our modalities of choice with angiography used earlier and magnetic resonance angiography (MRA) used when CT was contraindicated. Descriptive statistics and χ2 analyses were conducted. RESULTS: The imaging protocol successfully detected the level of the ASA in 132 (74.5%) patients, utilizing CTA in 67, DECT in 28, spinal angiography in 31, and MRA in 6. Cross sectional modalities with advanced visualization technique (CT, DECT, and MRA) were more successful at detecting the ASA than angiography (80.72%, 82.35%, 75% vs 59.62%, respectively, P = .04). Concerted efforts were made not to leave the operating room without continuity of the ASA with the circulation (via limited resection, beveled anastomosis, or reimplantation). Transient lower extremity weakness was observed in 11 (6.2%) patients, and permanent paraplegia in 2 (1.12%) patients. CONCLUSION: Modern imaging technology provides multiple methodologies highly successful at detecting the ASA. The ASA can then be preserved intraoperatively, contributing to low paraplegia rates. We strongly recommend routine application of this technology to arm the surgeon with precise information about the specific patient's spinal cord blood supply.

Bovine Aortic Arch: A Result of Chance or Mandate of Inheritance?

Previous studies have shown that bovine arch incidence is higher in patients with thoracic aortic aneurysms than in patients without an aneurysm. Although thoracic aortic aneurysm disease is known to be familial in some cases, it remains unknown if bovine arch results from a genetic mutation, thus allowing it to be inherited. Our objective was to determine the heritability of bovine arch from phenotypic pedigrees. We identified 24 probands from an institutional database of 202 living patients with bovine arch who had previously been diagnosed with thoracic aortic aneurysm and who had family members with previous chest computed tomography or magnetic resonance imaging scans. Aortic arch configuration of all first-degree and second-degree relatives was determined from available scans. Heritability of bovine arch was estimated using maximum-likelihood-based variance decomposition methodology implemented by way of the SOLAR package (University of Maryland, Catonsville, Maryland). 43 relatives of 24 probands with bovine arch had preexisting imaging available for review. The prevalence of bovine arch in relatives with chest imaging was 53% (n = 23) and did not differ significantly by gender (male: 64.3%, female: 55.6%, p = 1). The bovine arch was shown to be highly heritable with a heritability estimate (h2) of 0.71 (p = 0.048). In conclusion, the high heritability of bovine arch in our sample population suggests a genetic basis.

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.

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.

Left Atrial to Femoral Artery Full Cardiopulmonary Bypass: A Novel Technique for Descending and Thoracoabdominal Aortic Surgery.

Left atrial-femoral artery (LA-FA) bypass with a centrifugal pump and no oxygenator is commonly used for descending and thoracoabdominal aortic (DTAA) operations, mitigating the deleterious effects of cross-clamping. We present our initial experience performing DTAA replacement under LA-FA (left-to-left) cardiopulmonary bypass (CPB) with an oxygenator. DTAA replacement under LA-FA bypass with an oxygenator was performed in 14 consecutive patients (CPB group). The pulmonary vein and femoral artery (or distal aorta) were cannulated and the full CPB machine were used, including oxygenator, roller pump, pump suckers, and kinetically enhanced drainage. The CPB group was compared with 50 consecutive patients who underwent DTAA replacement utilizing traditional LA-FA bypass without an oxygenator (LA-FA group). Perioperative data were collected and statistical analyses were performed. All CPB patients maintained superb cardiopulmonary stability. The pump sucker permitted immediate salvage and return of shed blood. Superb oxygenation was maintained at all times. High-dose full CPB heparin was reversed without difficulty. The CPB group required markedly fewer blood transfusions than the LA-FA group (2.21 vs. 5.88 units, p < 0.004). The 30-day mortality rate was 7.1% ( n = 1) and there were no paraplegia cases in the CPB group versus 7 (14%) deaths and 3 (6%) paraplegia cases in the LA-FA group. Traditional LA-FA bypass without an oxygenator avoids high-dose heparin. In the present era, heparin reversal is more secure. Our experience finds that the novel application of LA-FA CPB with an oxygenator is safe and suggests improved hemodynamics (immediate return of shed blood) and a hemostatic advantage (avoidance of loss of coagulation factors in the cell saver).

Ascending Aortic Length and Risk of Aortic Adverse Events: The Neglected Dimension.

BACKGROUND: Little information is available regarding the longitudinal changes of the aneurysmal ascending aorta. OBJECTIVES: This study sought to outline the natural history of ascending thoracic aortic aneurysm (ATAA) based on ascending aortic length (AAL) and develop novel predictive tools to better aid risk stratification. METHODS: The ascending aortic diameters and lengths, and long-term aortic adverse events (AAEs) (rupture, dissection, and death) of 522 ATAA patients were evaluated using comprehensive statistical approaches. RESULTS: An AAL of ≥13 cm was associated with an almost 5-fold higher average yearly rate of AAEs compared with an AAL of <9 cm. Two AAL "hinge points" with a sharp increase in the estimated probability of AAEs were detected between 11.5 and 12.0 cm, and between 12.5 and 13.0 cm. The mean estimated annual aortic elongation rate was 0.18 cm/year, and aortic elongation was age dependent. Aortic diameter increased 18% due to dissection while AAL only increased by 2.7%. There was a noticeable improvement in the discrimination of the logistic regression model (area under the receiver-operating characteristic curve: 0.810) due to the introduction of aortic height index (AHI) (diameter height index + length height index). The AHIs <9.33, 9.38 to 10.81, 10.86 to 12.50, and ≥12.57 cm/m were associated with a âˆ¼4%, ∼7%, ∼12%, and ∼18% average yearly risk of AAEs, respectively. CONCLUSIONS: An aortic elongation of 11 cm serves as a potential intervention criterion for ATAA, which is even more reliable than diameter due to its relative immunity to dissection. AHI (including both length and diameter) is more powerful than any single parameter in this study.

Decision-making algorithm for ascending aortic aneurysm: Effectiveness in clinical application?

OBJECTIVE: The risk of rupture and dissection in ascending thoracic aortic aneurysms increases as the aortic diameter exceeds 5 cm. This study evaluates the clinical effectiveness of a specific algorithm based on size and symptoms for preemptive surgery to prevent complications. METHODS: A total of 781 patients with nondissecting ascending thoracic aortic aneurysms who presented electively for evaluation to our institution from 2011 to 2017 were triaged to surgery (n = 607, 77%) or medical observation (n = 181, 24%) based on a specific algorithm: surgery for large (>5 cm) or symptomatic aneurysms. A total of 309 of 781 patients did not undergo surgery. Of these, 128 (16%) had been triaged to prompt repair but did not undergo surgery for a variety of reasons ("surgery noncompliant and overwhelming comorbidities" group). Another 181 patients (24%) were triaged to medical management ("medical" group). RESULTS: In the "surgery noncompliant and overwhelming comorbidities" versus the "medical" group, mean aortic diameters were 5 ± 0.5 cm versus 4.45 ± 0.4 cm and aortic events (rupture/dissection) occurred in 17 patients (13.3%) versus 3 patients (1.7%), respectively (P < .001). Later elective surgeries (representing late compliance in the "surgery noncompliant and overwhelming comorbidities group" or onset of growth or symptoms in the "medical" group) were conducted in 21 patients (16.4%) versus 15 patients (8.3%) (P = .04), respectively. Death ensued in 20 patients (15.6%) versus 6 patients (3.3%) (P < .001), respectively. In the "surgery noncompliant and overwhelming comorbidities" group, 7 of 20 patients died of definite aortic causes compared with none in the "medical" group. CONCLUSIONS: Patients with ascending thoracic aortic aneurysms who did not follow surgical recommendations experienced substantially worse outcomes compared with medically triaged candidates. The specific algorithm based on size and symptoms functioned effectively in the clinical setting, correctly identifying both at-risk and safe patients.