Type A Aortic Dissection in Marfan Syndrome

Background—

Data on outcomes after Stanford type A aortic dissection in patients with Marfan syndrome are limited. We investigated the primary surgery and long-term results in patients with Marfan syndrome who suffered aortic dissection.

Methods and Results—

Among 1324 consecutive patients with aortic dissection type A, 74 with Marfan syndrome (58% men; median age, 37 years [first and third quartiles, 29 and 48 years]) underwent surgical repair (85% acute dissections; 68% DeBakey I; 55% composite valved graft, 30% supracoronary ascending replacement, 15% valve-sparing aortic root replacement; 12% total arch replacement; 3% in-hospital mortality) at 2 tertiary centers in the United States and Europe over the past 25 years. The rate of aortic reintervention with resternotomy was 24% (18 of 74) and of descending aorta (thoracic+abdominal) intervention was 30% (22 of 74) at a median follow-up of 8.4 years (first and third quartiles, 2.2 and 12.7 years). Freedom from need for aortic root reoperation in patients who underwent primarily a composite valved graft or valve-sparing aortic root replacement procedure was 95±3%, 88±5%, and 79±5% and in patients who underwent supracoronary ascending replacement was 83±9%, 60±13%, 20±16% at 5, 10, and 20 years. Secondary aortic arch surgery was necessary only in patients with initial hemi-arch replacement.

Conclusions—

Emergency surgery for type A dissection in patients with Marfan syndrome is associated with low in-hospital mortality. Failure to extend the primary surgery to aortic root or arch repair leads to a highly complex clinical course. Aortic root replacement or repair is highly recommended because supracoronary ascending replacement is associated with a high need (>40%) for root reintervention.

Abstract T P300: Stroke after Aortic Valve Surgery Increases Billing and Length of Stay

Background and Purpose: Aortic valve disease is increasing in prevalence as the population ages. We previously presented a prospective cohort of patients undergoing open surgical aortic valve replacement (AVR) and established that stroke is a frequent complication. However, the impact of stroke on the cost and length of hospitalization is not well characterized.

Methods: We performed a prospective cohort study of patients ≥ 65 years old undergoing open surgical aortic valve replacement for moderate to severe calcific aortic stenosis at two hospitals in our health system. Subjects were evaluated by neurologists at post-operative days 1, 3, and 7. Hospital billing charges, length of stay in the intensive care unit (ICU), and total hospital length of stay were compared between patients with and without stroke using rank sum. Correlations between stroke severity and hospital billing charges, length of stay in the ICU, and total hospital length of stay were evaluated using Spearman correlation.

Results: Complete hospital billing and length of stay data were available for 174 subjects, mean age 76 (standard deviation 6) years, 35% female, 6% non-white. Clinical stroke occurred in 28 (16%), median National Institutes of Stroke Scale (NIHSS) 3, interquartile range (IQR) 1 - 13. In-hospital mortality occurred in 9 (5%). Stroke was associated with increased total hospital billing charges, median $281,012 (IQR $218,754 - $304,031) vs $209,807 (IQR $175,163 - $273,755) for those without stroke, p=0.003. Clinical stroke was also associated with increased length of stay in the ICU, median 3 days (IQR 2 - 5) vs 1 day (IQR 1 - 2), p =0.0006, and total length of stay, 12 days (IQR 9 - 15) vs 10 days (IQR 8 - 13), p=0.01. Clinical stroke severity based on NIHSS was moderately correlated with total hospital billing charges (rho=0.49, p<0.0001), length of stay in the ICU (rho=0.53, p<0.0001), and total hospital length of stay (rho=0.36, p<0.0001). Excluding patients who died in the hospital did not change any of the findings.

Conclusions: Clinical stroke complicating valve replacement is associated with increased hospital billing charges, length of stay in the intensive care unit, and total hospital length of stay, all related to stroke severity.

Gender-related changes in aortic geometry throughout life

OBJECTIVES

Aortic geometry changes throughout life are not well defined. This investigation delineates aortic geometry across the adult age spectrum and determines the gender-related influence of aging on aortic morphometry.

METHODS

Contrast-enhanced computed tomography scans of all aortic segments in 195 subjects (94 women, 101 men, average age 57 ± 20 years) free of vascular disease were analysed. Lengths and diameters of each aortic segment as well as width, height and tortuosity of the thoracic aorta were compared between both genders.

RESULTS

Aortic diameters and lengths were larger in men than women (P < 0.001); however, after adjustment for body surface area (BSA), the ascending aorta and aortic arch revealed greater diameters in women than in men (P = 0.001 and P = 0.011, respectively). All aortic segment dimensions increased in a similar pattern with age for both genders, except the ascending aorta diameter, which increased +3.4% (P < 0.001) per decade in women and +2.6% (P < 0.001) per decade in men. Owing to more dynamic ascending aortic growth in women, absolute diameters were similar in both genders at an older age (>70 years old: 3.4 ± 0.3 vs 3.5 ± 0.3 cm, P = 0.241).

CONCLUSIONS

Female gender is associated with smaller aortic dimensions, but only at a young age. The dynamics of aortic growth throughout life are greater in women than in men. Gender-related changes in aortic geometry provide a hypothesis for the predominance of aortic dissection in young male patients, which normalizes between genders with increasing age.

Root stabilization of the repaired bicuspid aortic valve: subcommissural annuloplasty versus root reimplantation

BACKGROUND

At our institution, type I bicuspid aortic valve (BAV) patients with aortic insufficiency (AI) who are candidates for valve preservation are stratified into two groups by aortic root pathology: nonaneurysmal root undergoing primary cusp repair+subcommissural annuloplasty (repair group) vs aneurysmal root undergoing primary cusp repair+root reimplantation (reimplantation group). We report outcomes of this surgical reconstructive strategy for the repaired type I BAV.

METHODS

A retrospective review was performed of 71 patients with a type I BAV undergoing primary valve repair from 2005 to 2012. The repair group (n=40) underwent annular stabilization by subcommissural annuloplasty, and the reimplantation group (n=31) underwent robust annular stabilization provided by root reimplantation.

RESULTS

Preoperative characteristics and root anatomy were similar, except for increased root dimensions in the reimplantation group (p<0.001). Mortality, stroke, valve reoperation, and pacemaker requirement were zero in both groups. Postoperative peak (19±10 vs 11±5 mm Hg, p<0.001) and mean gradients (10±5 vs 5±3 mm Hg, p<0.001) favored root reimplantation. Freedom from AI greater than 1+ was 100% in both groups. Mean follow-up was 40 months in the reimplantation group and 38 months in the repair group. At 5 years, overall survival was 100% in both groups. Freedom from aortic reoperation and AI exceeding 2+ were similar in both groups. Freedom from AI exceeding 1+ was significantly better in the reimplantation group (92%±6% vs 62%±10%, p=0.03). The 2-year peak (14±6 vs 19±9 mm Hg, p=0.009) and mean (7±4 vs 11±5 mm Hg, p=0.001) gradients favored root reimplantation.

CONCLUSIONS

Root stabilization with the reimplantation technique significantly improves the durability of the repaired type I BAV compared with subcommissural annuloplasty. It also provides improved and sustained valve mobility (transvalvular gradients).

Validation of semiautomated and locally resolved aortic wall thickness measurements from computed tomography

OBJECTIVE

Aortic wall thickness (AWT) is important for anatomic description and biomechanical modeling of aneurysmal disease. However, no validated, noninvasive method for measuring AWT exists. We hypothesized that semiautomated image segmentation algorithms applied to computed tomography angiography (CTA) can accurately measure AWT.

METHODS

Aortic samples from 10 patients undergoing open thoracoabdominal aneurysm repair were taken from sites of the proximal or distal anastomosis, or both, yielding 13 samples. Aortic specimens were fixed in formalin, embedded in paraffin, and sectioned. After staining with hematoxylin and eosin and Masson's trichrome, sections were digitally scanned and measured. Patients' preoperative CTA Digital Imaging and Communications in Medicine (DICOM; National Electrical Manufacturers Association, Rosslyn, Va) images were segmented into luminal, inner arterial, and outer arterial surfaces with custom algorithms using active contours, isoline contour detection, and texture analysis. AWT values derived from image data were compared with measurements of corresponding pathologic specimens.

RESULTS

AWT determined by CTA averaged 2.33 ± 0.66 mm (range, 1.52-3.55 mm), and the AWT of pathologic specimens averaged 2.36 ± 0.75 mm (range, 1.51-4.16 mm). The percentage difference between pathologic specimens and CTA-determined AWT was 9.5% ± 4.1% (range, 1.8%-16.7%). The correlation between image-based measurements and pathologic measurements was high (R = 0.935). The 95% limits of agreement computed by Bland-Altman analysis fell within the range of -0.42 and 0.42 mm.

CONCLUSIONS

Semiautomated analysis of CTA images can be used to accurately measure regional and patient-specific AWT, as validated using pathologic ex vivo human aortic specimens. Descriptions and reconstructions of aortic aneurysms that incorporate locally resolved wall thickness are feasible and may improve future attempts at biomechanical analyses.

Oxidative stress modulates vascular smooth muscle cell phenotype via CTGF in thoracic aortic aneurysm

AIMS

Dissection and rupture of the ascending aorta are life-threatening conditions resulting in 80% mortality. Ascending aortic replacement in patients presenting with thoracic aortic aneurysm (TAA) is determined by metric measurement. However, a significant number of dissections occur outside of the parameters suggested by the current guidelines. We investigate the correlation among altered haemodynamic condition, oxidative stress, and vascular smooth muscle cell (VSMC) phenotype in controlling tissue homoeostasis.

METHODS AND RESULTS

We demonstrate using finite element analysis (FEA) based on computed tomography geometries that TAA patients have higher wall stress in the ascending aorta than non-dilated patients. We also show that altered haemodynamic conditions are associated with increased levels of reactive oxygen species (ROS), direct regulators of the VSMC phenotype in the microregional area of the ascending aorta. Using in vitro and ex vivo studies on human tissues, we show that ROS accumulation correlates with media layer degeneration and increased connective tissue growth factor (CTGF) expression, which modulate the synthetic VSMC phenotype. Results were validated by a murine model of TAA (C57BL/6J) based on Angiotensin II infusion showing that medial thickening and luminal expansion of the proximal aorta is associated with the VSMC synthetic phenotype as seen in human specimens.

CONCLUSIONS

Increased peak wall stress correlates with change in VSMC towards a synthetic phenotype mediated by ROS accumulation via CTGF. Understanding the molecular mechanisms that regulate VSMC towards a synthetic phenotype could unveil new regulatory pathways of aortic homoeostasis and impact the risk-stratification tool for patients at risk of aortic dissection and rupture.

Assessment of right ventricular function by transthoracic echocardiography following aortic valve replacement

BACKGROUND

Tricuspid annular plane systolic excursion (TAPSE) is a widely used clinical measure of right ventricular (RV) systolic performance. However, postsurgical changes in the pattern of RV contraction may limit the utility of TAPSE for assessing global RV function. We retrospectively examined pre- and postoperative TAPSE and RV fractional area change (FAC) in patients undergoing 3 different types of aortic valve replacement (AVR).

METHODS

Fifty-two patients enrolled in the Placement of AoRTic TraNscathetER Valve Trial at our institution were randomized to receive open AVR or transcatheter AVR (TAVR) by either the transapical or transfemoral access routes. Thirty-seven of these patients had analyzable transthoracic echocardiography (TTE) before and after AVR. Using M-mode echocardiography, TAPSE was measured in the apical four-chamber view. Using two-dimensional echocardiography, RV FAC was measured in the apical four-chamber view.

RESULTS

The mean change in TAPSE was -0.7 ± 0.6 cm for open AVR (P = 0.002), -0.2 ± 0.4 cm for transapical TAVR (P = 0.26), and 0.1 ± 0.5 cm for transfemoral TAVR (P = 0.64). The mean change in RV FAC was -1 ± 5% for open AVR (P = 0.91), 2 ± 4% for transapical TAVR (P = 0.37), and 7 ± 10% for transfemoral TAVR (P = 0.07).

CONCLUSIONS

The normal pattern of RV contraction was unchanged by transapical and transfemoral TAVR, while open AVR led to a significant decrease in TAPSE with preserved RV FAC. Thus, RV FAC is a preferable method for assessing RV function in the postoperative patient.

Type I and Type II hybrid aortic arch replacement: postoperative and mid-term outcome analysis

BACKGROUND

Hybrid aortic arch replacement has emerged as a safe treatment modality for arch aneurysms, especially in patients of old age and with greater comorbid burden. We assessed our institutional outcomes in patients undergoing Types I and II hybrid aortic arch replacement.

METHODS

From 2005 to 2012, 685 patients underwent thoracic endovascular repair (TEVAR), of whom 104 had hybrid arch repair (open + endovascular approach). 47 of these patients had treatment for aortic arch aneurysm ± proximal ascending aortic aneurysm. The hybrid repair entailed aortic arch vessel debranching and concomitant/delayed antegrade ± retrograde TEVAR stent grafting of the arch. Type III patients were excluded from the analysis. Data was prospectively maintained.

RESULTS

28 patients had Type I repair, 8 had Type II repair, and 11 had Type III repair. Mean age was 71±8 years. Primary aortic pathology was aneurysm (81%), followed by chronic arch dissection (11%). 14% of patients required reoperative cardiac surgery. Stent graft deployment rate was 100% after arch vessel debranching. Postoperative endoleak rate was zero. Average cardiopulmonary bypass time was 215±64 minutes, with crossclamp time of 70±55 minutes, and circulatory arrest time of 50±17 minutes. Paraplegia rate was 5.5% (n=2), with stroke rate of 8% (n=3) and renal failure rate of 3% (n=1) requiring hemodialysis. In-hospital mortality was 8% (n=3). Mean length of stay was 17.2±14 days. Median follow-up was 30±21 months. Freedom from all-cause mortality was 71%, 60%, and 48% at 1, 3, and 5 years respectively. Aortic reoperation rate was 2.7% (n=1). No patient had Type I or III endoleak at follow-up. Freedom from mortality was improved in cases performed more recently (July 2008 to 2012) than during our early experience (2005 to June 2008) (81% versus 44% at 3 years, P=0.05).

CONCLUSIONS

Hybrid aortic arch replacement can be performed with good postoperative and midterm results in a cohort of old patients with significant comorbidity. With greater experience, early and midterm outcomes continue to improve. The hybrid arch technique may represent a technical advancement in the field of aortic arch surgery.

Type II arch hybrid debranching procedure

Management of aortic arch aneurysm and dissection continues to evolve as endovascular options play an increasing role in treating thoracic aortopathies. Although conventional open treatment of aortic arch disease with total arch replacement still remains the gold standard, in patients with old age and/or high comorbid disease index, there is significant associated morbidity and mortality. The hybrid arch procedure, which aims to minimize cardiopulmonary bypass and circulatory arrest times, is a particularly appealing surgical option in this cohort of patients. The hybrid arch concept essentially entails three main principles: (I) open debranching of the great vessels; (II) creation of proper proximal (zone 0 landing) and distal landing zones, and; (III) concomitant or delayed endovascular stent grafting of the aortic arch. The classification scheme for hybrid arch debranching procedures is based on the extent of proximal and distal landing zone reconstruction required, and thus the need and extent of cardiopulmonary bypass and circulatory arrest management strategies to be employed. In this illustrated article, we describe the details of the type II hybrid arch debranching procedure, where the ascending aorta and aortic arch pathology is typically treated by reconstruction of ascending aorta ﹢ arch vessel debranching, with concomitant antegrade stent grafting of the aortic arch.

A meta-analysis of deep hypothermic circulatory arrest alone versus with adjunctive selective antegrade cerebral perfusion

INTRODUCTION

Recognizing the importance of neuroprotection in aortic arch surgery, deep hypothermic circulatory arrest (DHCA) now underpins operative practice as it minimizes cerebral metabolic activity. When prolonged periods of circulatory arrest are required, selective antegrade cerebral perfusion (SACP) is supplemented as an adjunct. However, concerns exist over the risks of SACP in introducing embolism and hypo- and hyper-perfusing the brain. The present meta-analysis aims to compare postoperative outcomes in arch surgery using DHCA alone or DHCA + SACP as neuroprotection strategies.

METHODS

Electronic searches were performed using six databases from their inception to January 2013. Two reviewers independently identified all relevant studies comparing DHCA alone with DHCA + SACP. Data were extracted and meta-analyzed according to pre-defined clinical endpoints.

RESULTS

Nine comparative studies were identified in the present meta-analysis, with 648 patients employing DHCA alone and 370 utilizing DHCA + SACP. No significant differences in temporary or permanent neurological outcomes were identified. DHCA + SACP was associated with significantly better survival outcomes (P=0.008, I(2)=0%), despite longer cardiopulmonary bypass time. Infrequent and inconsistent reporting of other clinical results precluded analysis of systemic outcomes.

CONCLUSIONS

The present meta-analysis indicate the superiority of DHCA + SACP in terms of mortality outcomes.

Transapical aortic valve replacement for severe aortic stenosis: results from the nonrandomized continued access cohort of the PARTNER trial

BACKGROUND

Transapical (TA) aortic valve replacement was an integral part of the Placement of Transcatheter Aortic Valves (PARTNER) trial. Enrollment during the randomized trial included 104 transapical (premarket approval TA [PMA-TA]) and 92 surgical aortic valve replacements (SAVR) within the TA cohort. On completion of the trial, enrollment continued in a nonrandomized continued access (NRCA) program. We compared the outcomes of NRCA-TA procedures with those of PMA-TA and SAVR.

METHODS

In 22 centers, 975 patients underwent TA aortic valve replacement as part of the NRCA registry. Inclusion and exclusion criteria were unchanged from the previously reported PARTNER trial. All patients were followed up for at least 1 year.

RESULTS

Thirty-day or in-hospital mortality was 8.8% for the NRCA-TA cohort, compared with 10.6% and 12.0% for the PMA-TA and SAVR patients, respectively (p = 0.54). One-year mortality in the NRCA-TA cohort was 22.1%, not significantly lower than the mortality in PMA-TA and SAVR patients at 29.0% and 25.3%, respectively (p = 0.27). Thirty-day or in-hospital stroke was 2.2% among NRCA-TA patients in contrast to the 6.7% stroke rate observed in the PMA-TA group and 5.4% in SAVR patients (p = 0.008). Lower rates of neurologic adverse events in the NRCA-TA group persisted at 1 year compared with the PMA-TA and SAVR patients.

CONCLUSIONS

Among the 975 patients in the NRCA-TA cohort, rates of major outcomes including death and stroke compared favorably with outcomes of PMA-TA and SAVR patients enrolled in the PARTNER trial. This trend toward improved outcomes may be attributed to improved patient selection, individual centers surmounting the procedural learning curve, and refinements in surgical technique.

Geometric orientation of the aortic neoroot in patients with raphed bicuspid aortic valve disease undergoing primary cusp repair and a root reimplantation procedure

OBJECTIVES

Primary cusp repair + aortic root reimplantation in bicuspid aortic valve (BAV) disease presenting with root aneurysm with aortic insufficiency (AI) is an effective surgical treatment. We assessed whether the geometric orientation of the repaired BAV into its reimplanted neoroot affects outcomes-180°/180° orientation was compared with the 150°/210° orientation.

METHODS

From 2005 to 2012, 66 BAV repairs were performed. This is a retrospective review of all types of Ib/II BAV AI patients undergoing root reimplantation (n = 26) at two different geometric orientations: 180°/180° (n = 11) vs 150°/210° (n = 15). In the 180°/180° group, reimplantation into the neoroot was such that both conjoint and non-conjoint cusps occupied 180° of the annular circumference. In the 150°/210° group, the repaired valve was configured to the more typical native orientation of a type I BAV: the non-conjoint cusp occupied 150°, and the conjoint cusp occupied 210° of the annular circumference.

RESULTS

Preoperative characteristics were similar in both groups. In-hospital mortality, stroke, reoperation, renal failure and pacemaker rates were zero in both groups. No patient left the operating room with >1+ AI and one had a peak gradient >20 mmHg. Transvalvular gradients were higher in the 180°/180° group, but not significant (P > 0.05). M.ean follow-ups for the 180°/180° and 150°/210° group were 48 and 33 months, respectively. Actuarial freedom from AI >2+ at 5 years was 100% in both groups. Freedom from AI >1+ at 5 years was 90 ± 10% in the 150°/210° group and 86 ± 13% in the 180°/180° group (P = 0.71). Freedom from peak gradient >20 mmHg was 80% (n = 8) in the 180°/180° group and 100% in the 150°/210° group at 1-year follow-up. Transvalvular gradients were higher in the 180°/180° group (16 ± 8 vs 10 ± 4 mmHg, P = 0.02; 9 ± 3 vs 5 ± 3 mmHg, P = 0.01). Five-year actuarial survival and freedom from aortic reoperation have remained at 100% in the entire cohort.

CONCLUSION

Cusp repair + root reimplantation for BAV type Ib/II AI can be safely performed at either geometric orientation. Conceptually, 150°/210° orientation respects the natural type I BAV anatomy with regard to cusp surface area and leaflet insertion perimeter. The 180°/180° group may have higher transvalvular gradients and smaller coaptation zones than the 150°/210° group. Further follow-up may reveal the superiority of one geometric orientation over the other.

Minimally invasive approach provides at least equivalent results for surgical correction of mitral regurgitation: a propensity-matched comparison

OBJECTIVE

Minimally invasive approaches to mitral valve surgery are increasingly used, but the surgical approach must not compromise the clinical outcome for improved cosmesis. We examined the outcomes of mitral repair performed through right minithoracotomy or median sternotomy.

METHODS

Between January 2002 and October 2011, 1011 isolated mitral valve repairs were performed in the University of Pennsylvania health system (455 sternotomies, 556 right minithoracotomies). To account for key differences in preoperative risk profiles, propensity scores identified 201 well-matched patient pairs with mitral regurgitation of any cause and 153 pairs with myxomatous disease.

RESULTS

In-hospital mortality was similar between propensity-matched groups (0% vs 0% for the degenerative cohort; 0% vs 0.5%, P = .5 for the overall cohort; in minimally invasive and sternotomy groups, respectively). Incidence of stroke, infection, myocardial infarction, exploration for postoperative hemorrhage, renal failure, and atrial fibrillation also were comparable. Transfusion was less frequent in the minimally invasive groups (11.8% vs 20.3%, P = .04 for the degenerative cohort; 14.0% vs 22.9%, P = .03 for the overall cohort), but time to extubation and discharge was similar. A 99% repair rate was achieved in patients with myxomatous disease, and a minimally invasive approach did not significantly increase the likelihood of a failed repair resulting in mitral valve replacement. Patients undergoing minimally invasive mitral repair were more likely to have no residual post-repair mitral regurgitation (97.4% vs 92.1%, P = .04 for the degenerative cohort; 95.5% vs 89.6%, P = .02 for the overall cohort). In the overall matched cohort, early readmission rates were higher in patients undergoing sternotomies (12.6% vs 4.4%, P = .01). Over 9 years of follow-up, there was no significant difference in long-term survival between groups (P = .8).

CONCLUSIONS

In appropriate patients with isolated mitral valve disease of any cause, a right minithoracotomy approach may be used without compromising clinical outcome.