Giovanni Battista Luciani

Fate of the Aortic Root Late After Ross Operation

Background—The Ross operation is an alternative to mechanical aortic valve replacement in the young. Early dilatation of the pulmonary autograft root exposed to the systemic circulation has been reported. To define the prevalence of, risk factors for, and consequences of late autograft dilatation, outcome in all consecutive patients operated since May 1994 was reviewed. Methods and Results—Ninety one patients, 77 males and 14 females, with at least 1 year of follow-up underwent cross-sectional clinical and echocardiographic examination. Age at operation was 27±10 years (range 6 to 49), and the indication was aortic regurgitation in 54 (59%) patients and bicuspid valve was present in 62 (68%). End-points of the study were freedom from autograft dilatation (root diameter >4 cm or 0.21 cm/m2), from (moderate) autograft regurgitation and from reoperation. Follow-up (4.0±1.9, range 1 to 8 years) autograft root diameters were anulus, 29±4 mm (18–39); sinus of Valsalva, 38±7 mm (24–53); sinotubular junction, 37±6 mm (23–54); and ascending aorta, 37±5 mm (27–54). Late autograft dilatation was identified in 31 (34%) patients and regurgitation in 13 (14%), 7 of whom had autograft dilatation. At 7 years, freedom from dilatation was 42±8%, freedom from regurgitation was 75±8%, and freedom from reoperation was 85±10%. Cox proportional hazard analysis identified younger age (P =0.05), preoperative sinus of Valsalva (P =0.02), root replacement technique (P =0.03), and absence of pericardial buttressing (P =0.04) as predictive of autograft dilatation, whereas female sex (P =0.002), follow-up sinus of Valsalva (P =0.003), and sinotubular junction diameter (P =0.02) as predictive of autograft regurgitation. Conclusions—Autograft dilatation is common late after the Ross procedure, particularly in younger patients, in those with preoperative aortic aneurysm, and those having root replacement without support of anulus and sinotubular junction. Bicuspid aortic valve is not a risk factor. Significant autograft valve dysfunction affects a minority of patients, but it is more prevalent in those with autograft dilatation.

One-stage repair of interrupted aortic arch, ventricular septal defect, and subaortic obstruction in the neonate: A novel approach

BACKGROUND One-stage repair of interrupted aortic arch, ventricular septal defect, and severe subaortic stenosis represents a surgical challenge. Techniques that use extracardiac conduits to bypass the subaortic area or involve transaortic or transatrial resection of the conal septum have shown limitations and have failed to reduce the high mortality rate associated with subaortic obstruction. METHODS AND RESULTS A new operative approach was used in nine neonates (2.1 to 3.9 kg) who underwent one-stage repair of interrupted aortic arch (type B, eight patients; type C, one patient), ventricular septal defect, and severe subaortic stenosis. All patients had severe subaortic stenosis according to preoperative echocardiography (mean ratio of subaortic to descending aortic diameter, 0.63 +/- 0.08). With a transpulmonary (seven patients) or transatrial (two patients) approach and without resection of the conal septum, the ventricular septal patch was placed on the left side of the septum to deflect the conal septum anteriorly and away from the subaortic area. There were no early or late deaths. Median intensive care unit and hospital stays were 17 days (6 to 47 days) and 21 days (10 to 55 days), respectively. On follow-up echocardiography (1 to 29 months, median 12 months), no patients had significant residual subaortic obstruction and one patient had mild residual arch obstruction (20 mm Hg). Growth of the subaortic region was demonstrated in all patients (mean ratio of subaortic to descending aortic diameter, 1.20 +/- 0.10; < 0.001). CONCLUSIONS Relief of severe subaortic stenosis during one-stage neonatal repair of aortic arch interruption and ventricular septal defect can be accomplished successfully without resection of the conal septum.

Risk of late reoperations in patients with acute type A aortic dissection : impact of a more radical surgical approach

OBJECTIVE To evaluate the incidence and risk factors for reoperations on the pre-isthmic aorta after repair of type A acute aortic dissection. METHODS From January 1979 to December 1996, 178 patients (125 males and 53 females with a mean age of 57 +/- 9 years) underwent emergency surgery for acute type A aortic dissection with an overall operative mortality rate of 21%. One hundred and forty-one patients (100 males and 41 females, aged 58 +/- 12 years), were discharged after successful replacement of the ascending aorta in 136 cases (96%) with extension to the transverse arch in 22 (16.2%) and associated total root or aortic valve replacement in 31 (22.8%) and 6 (4.4%) cases, respectively. Intimal tear resection and direct primary anastomosis of the aorta were performed in 5 patients (4%). Total follow-up was 690 patient-years, mean 5.1 +/- 4.1 years, with an actuarial survival rate at 5,10 and 15 years of 88%, 73% and 42%, respectively. RESULTS Nineteen patients (13%), 13 males and 6 females, aged 50 +/- 10 years, required a total of 22 reoperations with an actuarial freedom from reoperation at 5, 10 and 15 years of 94%, 64% and 35%, respectively. Initial repair consisted of replacement of the ascending aorta in 16 (84%) cases, with total root replacement in 2 (12%) and isolated aortic valve replacement in 1 (6%). Three patients (16%) were treated by intimal tear resection and direct primary anastomosis of the aorta. Mean interval between initial repair and reoperation was 5.2 +/- 3.1 years and indication to re-do surgery were severe aortic regurgitation in 2 (11%), aneurysmal evolution of the false lumen in 4 (21%) or both in 13 (68%). Extensive aortic reconstruction comprising simultaneous graft replacement of the aortic root, ascending aorta and aortic arch was necessary in 13 cases (68%), isolated replacement of the ascending aorta in 3 (16%), aortic valve in 2 (11%) and aortic arch in 1 (5%). There were 1 hospital (5%) and 2 late (11%) deaths at a mean follow-up of 2.5 +/- 2.4 years, with an actuarial survival at 5 years of 88%. Retrospective analysis of our total experience revealed that the introduction of the open distal anastomosis technique since 1990, reduced the incidence of reoperation from 11/46 (24%) to 8/95 (8.4%) (P < 0.05). However, also with this strategy 8/73 (11%) patients surviving replacement limited to the ascending aorta required reoperation versus none of the 22 patients surviving repair extended to the aortic arch. Three out of 5 (60%) patients undergoing intimal tear resection and primary anastomosis of the aorta early in our experience, required reoperation. CONCLUSIONS Management of patients with acute type A aortic dissection may include one or more surgical procedures after the initial emergency repair. Reoperations carry a low operative risk with good long-term survival and their incidence is reduced by routine open distal anastomosis and aggressive replacement of the aortic arch. Intimal tear resection and primary anastomosis of the aorta appear to be associated with increased risk of reoperation.

Preservation of the aortic valve in acute type A dissection complicated by aortic regurgitation

BACKGROUND The aim of the present study was to verify the efficacy of preserving the aortic valve in patients with acute type A aortic dissection complicated by significant aortic regurgitation. METHODS From January 1979 to December 1996, 178 patients (125 males; mean age 57 +/- 9 years) underwent emergency surgery for acute type A aortic dissection, with an overall operative mortality rate of 21%. Based on a retrospective analysis of the preoperative angio- or echocardiographic findings, the 141 survivors were divided into 2 groups: Group 1 (G1) included 80 patients (57%) with no or mild aortic regurgitation, and Group 2 (G2) the remaining 61 patients with moderate-to-severe aortic regurgitation. The native aortic valve was preserved by means of a uniform technique consisting of reconstruction of the aortic root and sinotubular junction in 99 patients (70%) [68 in G1 (85%) and 31 in G2 (51%)]. Forty-two patients required aortic valve (8 patients; 6%) or total root replacement (34 patients; 24%). RESULTS At a mean follow-up of 4 +/- 3.6 years (range, 6 months to 19 years), 19 of the 99 patients with a preserved aortic valve developed moderate-to-severe aortic insufficiency [19%; 7/68 in G1 (10%) and 12/31 in G2 (39%)]. Multivariate analysis revealed that moderate-to-severe preoperative aortic valve insufficiency was a significant risk factor for development of postoperative aortic valve regurgitation (p = 0.008). Reoperation was necessary in 7 G1 patients (10%) and in 8 G2 patients (26%), with an actuarial freedom from reoperation at 5 and 10 years of 93% +/- 7% and 80% +/- 9% in G1 patients, and 81% +/- 8% and 40% +/- 15% in G2 patients (p = 0.045). CONCLUSIONS Preservation of the aortic valve and aortic root is recommended in patients with acute type A aortic dissection and absent or mild aortic insufficiency. Patients presenting with moderate-to-severe aortic regurgitation and treated conservatively present an increased risk of recurrent valvular insufficiency.

Comparative finite element model analysis of ascending aortic flow in bicuspid and tricuspid aortic valve.

In bicuspid aortic valve (BAV) disease, the role of genetic and hemodynamic factors influencing ascending aortic pathology is controversial. To test the effect of BAV geometry on ascending aortic flow, a finite element analysis was undertaken. A surface model of aortic root and ascending aorta was obtained from magnetic resonance images of patients with BAV and tricuspid aortic valve using segmentation facilities of the image processing code Vascular Modeling Toolkit (developed at the Mario Negri Institute). Analytical models of bicuspid (antero-posterior [AP], type 1 and latero-lateral, type 2 commissures) and tricuspid orifices were mathematically defined and turned into a volumetric mesh of linear tetrahedra for computational fluid dynamics simulations. Numerical simulations were performed with the finite element code LifeV. Flow velocity fields were assessed for four levels: aortic annulus, sinus of Valsalva, sinotubular junction, and ascending aorta. Comparison of finite element analysis of bicuspid and tricuspid aortic valve showed different blood flow velocity pattern. Flow in bicuspid configurations showed asymmetrical distribution of velocity field toward the convexity of mid-ascending aorta returning symmetrical in distal ascending aorta. On the contrary, tricuspid flow was symmetrical in each aortic segment. Comparing type 1 BAV with type 2 BAV, more pronounced recirculation zones were noticed in the latter. Finally, we found that in both BAV configurations, maximum wall shear stress is highly localized at the convex portion of the mid-ascending aorta level. Comparison between models showed asymmetrical and higher flow velocity in bicuspid models, in particular in the AP configuration. Asymmetry was more pronounced at the aortic level known to be more exposed to aneurysm formation in bicuspid patients. This supports the hypothesis that hemodynamic factors may contribute to ascending aortic pathology in this subset of patients.

Recurrence of aortic insufficiency after aortic root remodeling with valve preservation

BACKGROUND Aortic root remodeling (ARR) has recently been proposed for patients with aortic aneurysms and valve insufficiency (AI). To define factors associated with a favorable functional outcome, a review of the mid-term results with ARR was undertaken. METHODS Between March 1994 and October 1997, 17 consecutive patients (11 men, 6 women), aged 57 +/- 11 years (range 35-71), had elective ARR for aortic aneurysm with or without annuloaortic ectasia (13), sinus of Valsalva aneurysm (3), or chronic aortic dissection (1). Moderate or severe AI was present in 11 patients (65%). Preoperative aortic root diameter was 58 +/- 5 mm (range 51-70). ARR involved replacement of all three aortic sinuses and coronary button reimplantation, using grafts with a mean diameter of 28 +/- 2 mm (range 24-30). RESULTS There was one early death (6%) due to multiple organ failure. Survivors were followed for 16 +/- 12 months (range 1-44). Actuarial 3-year survival was 94% +/- 6%. Discharge echocardiogram showed a decrease in AI in all patients: AI was absent in 11 (69%) and mild in 5 (31%). Recurrence of moderate or severe AI after a mean of 16 +/- 9 months (range 9-28) was noted in 6 patients (37%), 3 of whom had no AI at discharge. Five of 6 patients required aortic valve replacement. Comparison of demographic and operative variables showed that severe preoperative AI (67% vs 20%, p = 0.06), annuloaortic ectasia (100% vs 20%, p = 0.002), and cystic medial necrosis (100% vs 20%, p = 0.002) were significantly more prevalent in patients developing severe AI at follow-up. The 10 patients (63%) with absent AI showed durable competence of the valve and relief from symptoms at follow-up. CONCLUSIONS Despite early restoration of valve competence, AI may recur and progress after ARR at medium-term follow-up in a proportion of patients. The severity of preoperative AI and the nature of aortic root disease may negatively influence the durability of repair. Continued observation of results with ARR appears mandatory to identify the appropriate surgical candidates.

Survival after stentless and stented xenograft aortic valve replacement: a concurrent, controlled trial

BACKGROUND To define the impact of stentless versus stented valve design on survival late after xenograft aortic valve replacement, a retrospective analysis of all consecutive patients operated on between January 1992 and April 2000 was undertaken. METHODS Two hundred ninety-two patients had stented (group 1) and 376 stentless (group 2) xenograft aortic valve replacements. Age was older in group 1 (75 +/- 4 vs 70 +/- 7 years, p = 0.01), whereas male gender and aortic stenosis were equally prevalent. Advanced New York Heart Association class III-IV (85% vs 78%, p = 0.03) and associated procedures (53% vs 41%, p = 0.01) were more common in group 1. Aortic cross-clamp (80 +/- 28 vs 96 +/- 23 minutes, p = 0.01) and bypass (91 +/- 56 vs 129 +/- 34 minutes, p = 0.01) times were shorter in group 1. Logistic regression and Cox proportional hazard methods were used to define the role of demographic and operative variables on hospital and late survival, freedom from valve-related mortality, and reintervention. RESULTS Early mortality was higher in group 1 (6.2% vs 2.6%, p = 0.02). Smaller aortic anulus (p = 0.008), aortic cross-clamp (p = 0.03), and coronary disease requiring bypass (p = 0.03) were associated with hospital mortality. During follow-up (37 +/- 30 vs 43 +/- 35 months, p = NS), 66 late deaths were recorded (12% vs 9%, p = NS). At 8 years, survival (70 +/- 5% vs 81 +/- 3%, p = 0.01), freedom from cardiac- (85 +/- 1% vs 92 +/- 3%, p = 0.02), and valve-related death (79 +/- 5% vs 95 +/- 2%, p = 0.004) were higher in group 2. Freedom from structural deterioration was similar (92 +/- 5% vs 93 +/- 3%, p = NS), but freedom from reoperation was lower in group 2 (99 +/- 1% vs 90 +/- 4%, p = 0.009). Multivariate analysis showed female gender (p = 0.02), age (p = 0.03), and smaller valve size (p = 0.05) to be associated with late mortality; age (p = 0.06) and diagnosis of aortic stenosis (p = 0.008) with cardiac mortality; longer intensive care unit stay (p = 0.001) and stented xenografts (p = 0.05) with valve-related mortality; and younger age (p = 0.01) and stentless xenograft (p = 0.05) with reoperation. CONCLUSIONS Use of stentless xenografts correlates with better survival and freedom from cardiac- and valve-related mortality than stented valves. However, bias favoring stented valves in older and sicker patients exists. Selective survival advantage of stentless xenograft is confined to valve-related mortality. Stentless valves are more likely to be replaced for dysfunction.

Primary cardiac leiomyosarcoma: seven-year survival with combined surgical and adjuvant therapy

Primary cardiac sarcomas constitute a rare entity that have been uniformly associated with poor long-term survival. A case of left atrial leiomyosarcoma involving the interatrial septum and the right atrial free wall and presenting with syncope and atrial fibrillation, is described. Two extensive surgical excisions followed by adjuvant radiation and chemotherapy improved survival with a good quality of life. This approach of combined surgical, medical and radiation therapy may offer better longterm outcome, since our patient is the longest survivor thus far reported.

Influence of Bicuspid Valve Geometry on Ascending Aortic Fluid Dynamics: A Parametric Study

Bicuspid aortic valve (BAV) predisposes to aortic aneurysms with a high prevalence. A first hypothesis for this phenomenon is related to fibrillin deficiency (genetic hypothesis). The present article focused on a complementary, hemodynamic hypothesis stating that it is the peculiar fluid dynamics of blood in the ascending aorta of patients with BAV configurations that leads to aneurysm formation. To corroborate this hypothesis, a parametric study was performed based on numerical simulations of ascending aorta hemodynamics with different configurations of orifice area and valve orientation. The resulting wall shear stress (WSS) distributions and degree of asymmetry of the blood jet were investigated, and surrogate indices introduced. The results showed that WSS was more pronounced in subjects with BAV morphologies, also in the nonstenotic case. In particular, a maximum WSS of 3Pa was found (vs. 1.5Pa in subjects with a tricuspid configuration). It is localized at the mid-ascending aorta, the segment more prone to dilate as shown by the index related to maximum WSS (0.869 in BAV vs. 0.322 in tricuspid). Moreover, the asymmetry of the blood flow was found larger for decreasing valve area, the related index at mid-ascending aorta being more than three times higher than that found for tricuspid configuration (0.70 vs. 0.20). Further, WSS and flow asymmetry were higher also at the sinus of Valsalva and sinotubolar junction for a latero-lateral (LL) BAV configuration in keeping with the clinical observation on association between BAV configurations and different aortic aneurysm morphology. These findings may help explain the higher risk of aneurysm formation in BAV patients. The proposed indices will require validation prior to application in clinical settings.

Predictors of left ventricular outflow obstruction following single-stage repair of interrupted aortic arch and ventricular septal defect

This study looked at echocardiographic predictors of left ventricular outflow obstruction after primary neonatal repair of interrupted aortic arch and ventricular septal defect. Results of this study indicate that the only significant independent predictor of left ventricular outflow obstruction is aortic valve diameter; all patients with an aortic valve diameter <4.5 mm (Z score <-5) subsequently developed obstruction, whereas patients with annuli >4.5 mm (Z score >-5) remained free from obstruction.