Valve-Sparing Aortic Root Replacement: Current State of the Art and Where Are We Headed?

Valve-Sparing Aortic Root Replacement With Reimplantation vs Remodeling: A Meta-analysis

BACKGROUND

Long-term outcomes of valve-sparing aortic root replacement (VSARR) with reimplantation vs remodeling in patients undergoing aortic root surgery remains a controversial subject.

METHODS

This study was a pooled meta-analysis of Kaplan-Meier-derived data from comparative studies published by December 31, 2022.

RESULTS

Fifteen studies met our eligibility criteria, comprising 3044 patients (1991 in the reimplantation group and 2018 in the remodeling group). Patients who underwent VSARR with remodeling had a higher risk of all-cause death (hazard ratio [HR], 1.54; 95% CI, 1.16-2.03; P = .002, log-rank test P < .001). Landmark analysis (with 4 years as the landmark time point) demonstrated that survival was lower in patients who underwent VSARR with remodeling (HR, 2.15; 95% CI, 1.43-3.24; P < .001) in the first 4 years. Beyond the 4-year time point, no difference in survival was observed (HR, 1.04; 95% CI, 0.72-1.50; P = .822). The risk for need of aortic valve and/or root reintervention was higher in patients undergoing VSARR with remodeling (HR, 1.49; 95% CI, 1.07-2.07; P = .019, log-rank test P < .001). We did not find statistically significant coefficients for the covariates of age, female sex, connective tissue disorders, bicuspid aortic valve, aortic dissection, coronary bypass surgery, total arch replacement, or annular stabilization, which means that these covariates did not modulate the effects observed in our pooled analyses.

CONCLUSIONS

VSARR with reimplantation is associated with better overall survival and lower risk of need for reintervention over time compared with VSARR with remodeling. Regarding overall survival, we observed a time-varying effect that favored the reimplantation technique up to 4 years of follow-up, but not beyond this time point.

Outcomes of Valve-Sparing Surgery in Heritable Aortic Disorders: Results from the AVIATOR Registry

OBJECTIVES

Root reimplantation has been the favored approach for patients with heritable aortic disorder (HAD) requiring valve-sparring root replacement (VSRR). In the past few years, root remodelling with annuloplasty has emerged as an alternative to root reimplantation in the general population. The aim of this study was to examine the late outcomes of patients with HAD undergoing VSRR and compare different techniques.

METHODS

Using the AVIATOR registry, data were collected from 5 North American and European centers. Patients were divided in 4 groups according to the technique of valve-sparing used (root reimplantation, root remodelling with ring annuloplasty, root remodelling with suture annuloplasty and root remodelling alone). The primary end-points were freedom from aortic regurgitation (AR) ≥2 and freedom from reintervention on the aortic valve. Secondary end-points were survival and changes in annular dimensions over time.

RESULTS

A total of 237 patients were included in the study (reimplantation= 100, remodelling + ring annuloplasty= 76, remodelling + suture annuloplasty= 34, remodelling alone= 27). The majority of patients had Marfan syndrome (82%). Preoperative AR ≥ 2 was present in 41% of the patients. Operative mortality was 0.4% (n = 1). No differences were found between techniques in terms of postoperative AR ≥ 2 (p = 0.58), reintervention (p = 0.52) and survival (p = 0.59). Changes in aortic annulus dimension were significantly different at 10 years (p < 0.05), a difference that started to emerge 4 after years surgery.

CONCLUSIONS

Overall, VSRR are safe and durable procedures in patients with HAD. Nevertheless, root remodelling alone is associated with late annular dilatation. Addition of an annuloplasty, however, results in similar freedom from AR, reintervention, survival, and changes in annulus size compared to reimplantation.

A New Technique for Shaping the Aortic Sinuses and Conserving Dynamism in the Remodeling Operation

BACKGROUND

Preserving dynamism and recreating the sinuses in the Dacron graft are thought to be important for optimizing results of aortic valve-conserving operations.

METHODS

We describe a novel technique that preserves dynamism and recreates the sinotubular junction. In addition, it tailors 3 sinuses of defined longitudinal and transverse curvatures in a straight Dacron tube during the operation. The technique has been used in 6 patients with varied aortic root pathology. We performed preoperative and postoperative multimodality imaging using computerized image analysis as well as 3-dimensional models.

RESULTS

There was no early or midterm death. Upon discharge, patients were clinically well, with echocardiographic evidence of minimal (3 patients) or mild (3 patients) aortic regurgitation. Computed tomography and cardiac magnetic resonance imaging with extensive image analysis of the aortic root size, shape, and function showed partial or complete normalization of these parameters. This included the shape and dynamism of the aortic annulus and the size and shape of the geometric (effective) orifice. The 4-dimensional magnetic resonance imaging pattern of flow in the sinuses and ascending aorta showed favorable vortices in the sinuses, right-handed helical flow, and marked diminution of energy loss in the ascending aorta.

CONCLUSIONS

The novel technique described here is simple, practical, and cost-effective because it uses a widely available straight Dacron tube. The technique does not use rigid internal or external support. The early results are encouraging. Larger series with longer follow-up are required.

A novel device for technical standardization of valve-sparing aortic root reimplantation

Among valve-sparing aortic root replacement techniques developed for the treatment of aortic root aneurysms and aortic insufficiency, the reimplantation technique (the David procedure) has proved to provide excellent outcomes in experienced hands. However, it involves certain challenges in technical standardization, particularly for graft sizing, which is still far from standardization. A novel device was developed to facilitate and provide all the measurements in high precision and accuracy required for the David procedure. The device allows easy, rapid, and accurate acquisition of the patient"s data and appropriate configuration of the aortic valve, irrespective of the surgeon's subjective evaluations. This all-in-one device provides all the major parameters including graft size, effective height, graft preparation, and simulation of the aortic coaptation. The device was successfully tested on a Devotini aortic root simulator and on a bovine heart ex vivo. The device proposed herein to be used for reimplantation has one explicit advantage: all valve geometry to be reconstructed and repaired can be simulated on the device with all its elements, in particular, the commissures and the cusps. Thus, all that is necessary can be clearly visualized in a manner whatever the configuration the surgeon prefers, particularly the creation of the effective height.

Aortic root surgery in Marfan syndrome

Marfan syndrome (MFS) is an autosomal dominant connective disease etiologically related with FBN-1 gene mutation. The altered microfibril protein structure result in characteristic cardiovascular abnormalities including aortic root dilatation, aortic root aneurysms, and aortic dissections. Aortic root aneurysms and subsequent dissection are the major causes of reduced life expectancy in MFS patients. Prophylactic aortic root replacement has improved the survival of patients with MFS. Elective root replacement carries very low mortality and morbidity. Emergency root replacement for dissection is accompanied with higher early mortality and late deaths/interventions. Both the techniques of aortic root replacement, total root replacement (TRR) with a prosthetic valved conduit, and valve-sparing root replacement (VSRR) yield excellent early and late results. Considering the low risk of prosthetic valve-related events, the improved long-term survival, and event-free survival, TRR continues to be a very effective surgical option. VSSR also seems to be a good option for the first 10 to 15 years following surgery in MFS patients. The choice of procedure depends upon available expertise, patients' choice, feasibility of anticoagulation, possibility of pregnancy, and lifestyle of the patient. Aortic root morphology and state of valve cusps also affect the decision making. In recent times, personalized external aortic root support (PEARS) with a macroporous mesh sleeve has also emerged as a promising alternative to aortic root replacement. All these patients need close monitoring for whole life after surgical intervention.

Partial aortic root remodeling for root reconstruction in patients with acute type A dissection

In the present study, we reported our experience with partial aortic root remodeling for root reconstruction in patients with acute type A dissection, which involves in non-coronary sinus and/or the right coronary sinus with just one trimmed Dacron graft. Between February 2001 and May 2010, we performed partial aortic root remodeling in 40 patients, who underwent emergency surgical intervention. The dissected sinuses were excised leaving a 3-5 mm rim of the aortic wall from the attached aortic valve cusps. A short piece (4-5 cm) of collagen coated woven polyester vascular prosthesis was trimmed with one or two “tongues” to reconstruct the non-coronary sinus and/or the right coronary sinus, but without using separated patches. Additional procedures were including hemi-arch replacement in 11 patients, and total arch replacement plus stent-elephant trunk in 20 patients. The mean follow-up time was 36.4±3.6 months. In-hospital mortality was only 5.0% (2/40); furthermore, 3 (8.6%) patients underwent re-operation of the aortic valve and 2 (5.7%) patients died during follow-up. At the end of follow-up, trivial or no aortic regurgitation was found in 33 patients, but mild aortic regurgitation was found in 2 patients. Our data suggest that the early and mid-term results of partial aortic root remodeling were favorable, and it restored valve durability and function. Thus, the use of technique for root reconstruction in patients with acute type A dissection should be vigorously encouraged.

Long-term survival, valve durability, and reoperation for 4 aortic root procedures combined with ascending aorta replacement

OBJECTIVE

To evaluate long-term results of aortic root procedures combined with ascending aorta replacement for aneurysms, using 4 surgical strategies.

METHODS

From January 1995 to January 2011, 957 patients underwent 1 of 4 aortic root procedures: valve preservation (remodeling or modified reimplantation, n = 261); composite biologic graft (n = 297); composite mechanical graft (n = 156); or allograft root (n = 243).

RESULTS

Seven deaths occurred (0.73%), none after valve-preserving procedures, and 13 strokes (1.4%). Composite grafts exhibited higher gradients than allografts or valve preservation, but the latter 2 exhibited more aortic regurgitation (2.7% biologic and 0% mechanical composite grafts vs 24% valve-preserving and 19% allografts at 10 years). Within 2 to 5 years, valve preservation exhibited the least left ventricular hypertrophy, allograft replacement the greatest; however, valve preservation had the highest early risk of reoperation, allograft replacement the lowest. Patients receiving allografts had the highest risk of late reoperation (P < .05), and those receiving composite mechanical grafts and valve preservation had the lowest. Composite bioprosthesis patients had the highest risk of late death (57% at 15 years vs 14%-26% for the remaining procedures, P < .0001), because they were substantially older and had more comorbidities (P < .0001).

CONCLUSIONS

These 4 aortic root procedures, combined with ascending aorta replacement, provide excellent survival and good durability. Valve-preserving and allograft procedures have the lowest gradients and best ventricular remodeling, but they have more late regurgitation, and likely, less risk of valve-related complications, such as bleeding, hemorrhage, and endocarditis. Despite the early risk of reoperation, we recommend valve-preserving procedures for young patients when possible. Composite bioprostheses are preferable for the elderly.

Early and late management of type B aortic dissection

The management of type B aortic dissection is undergoing profound changes with timely TEVAR accepted as first-line strategy in the setting of complicated dissection; with recent technological advances and in experienced hands this intervention is considered safe and life-saving. With the ability to remodel the dissected aorta as a result of scaffolding even pre-emptive endovascular treatment is being considered and supported by long-term stability and often prevention of aneurysmal expansion. This insight and a growing number of silent risk conditions (resistant hypertension, partial false lumen thrombosis) may lower the threshold for TEVAR in asymptomatic patients in the subacute phase. In the chronic phase of a type B dissection patients are usually free of symptoms, however, with the expanding false lumen at risk of rupture. Advanced TEVAR options (including branches and fenestrations) are likely to be used more often than open surgical replacement of such aneurysmatic segment of the dissected aorta in that chronic phase. All dissection patients should be offered lifelong surveillance.

Aortic valve and aortic root features in CT angiography in patients considered for aortic valve repair

BACKGROUND

The underlying mechanism of aortic regurgitation and aortic valve and root characteristics are associated with the durability of surgical repair.

OBJECTIVE

We investigated whether multidetector CT (MDCT) identifies the characteristics of the aortic valve and root that may be associated with the ability to perform successful surgical repair.

METHODS

Sixty-one patients with aortic regurgitation and/or aortic root pathology who were evaluated for aortic valve or root repair and underwent clinically indicated gated or nongated MDCT of the aortic valve and aortic root were included in the present analysis. Patients with endocarditis were excluded. MDCT data of aortic valve anatomy and calcification and thoracic aorta dimensions were analyzed.

RESULTS

The aortic valve and root was successfully repaired in 36 patients (55 ± 13 years; 61% male; median EuroSCORE II, 3.8%) whereas in 25 patients (56 ± 15 years; 52% male; median EuroSCORE II, 2.5%) repair was not attempted (n = 20) or valve repair was converted to aortic valve replacement during surgery (n = 5). In patients in whom repair was considered not possible or failed, there was a higher percentage of bicuspid aortic valves (48% vs 17%; P = .019), more severe commissural calcification, and more severe annular calcification.

CONCLUSION

The degree of commissural and annular calcification of the aortic valve determined by MDCT is inversely related to the ability to perform surgical valve repair instead of replacement. Similarly, bicuspid valve anatomy predicts failure to perform repair.

Aortic valve repair--current status, indications, and outcomes

Aortic valve repair is a new development with old roots. In the past 20 years, marked progress has been made in understanding the normal anatomy of the aortic valve and the interrelation between cusps and root. Aortic dilatation is the single most frequent pathogenetic factor in aortic regurgitation, accompanied by cusp pathology, that is, prolapse or congenital anomaly in most industrialized countries. Frequently, aortic and cusp pathology coexist. Different operative techniques have been established for correction of aortic and cusp pathology. Experience has shown that the combined application of repair procedures will lead to good results if normal valve and cusp configuration is achieved. Some congenital anomalies may require design alteration of the aortic valve. Low-operative mortality rates have been reported consistently. When adequate repair durability is achieved, the incidence of valve-related complications is lower than what has been reported for valve replacement. Aortic valve repair is currently in transition from surgical improvisation to a reproducible operation and an option for many patients with aortic regurgitation. Current research focuses on some special aspects, such as stabilization of the basal ring, ideal material and technique for cusp replacement, and more objective information on ideal valve configuration.

Cardiovascular magnetic resonance in Marfan syndrome

This review provides an overview of Marfan syndrome with an emphasis on cardiovascular complications and cardiovascular imaging. Both pre- and post-operative imaging is addressed with an explanation of surgical management. All relevant imaging modalities are discussed with a particular focus on cardiovascular MR.

David valve-sparing aortic root replacement: equivalent mid-term outcome for different valve types with or without connective tissue disorder

OBJECTIVE

Although implicitly accepted by many that the durability of valve-sparing aortic root replacement in patients with bicuspid aortic valve disease and connective tissue disorders will be inferior, this hypothesis has not been rigorously investigated.

METHODS

From 1993 to 2009, 233 patients (27% bicuspid aortic valve, 40% Marfan syndrome) underwent Tirone David valve-sparing aortic root replacement. Follow-up averaged 4.7 ± 3.3 years (1102 patient-years). Freedom from adverse outcomes was determined using log-rank calculations.

RESULTS

Survival at 5 and 10 years was 98.7% ± 0.7% and 93.5% ± 5.1%, respectively. Freedom from reoperation (all causes) on the aortic root was 92.2% ± 3.6% at 10 years; 3 reoperations were aortic valve replacement owing to structural valve deterioration. Freedom from structural valve deterioration at 10 years was 96.1% ± 2.1%. No significant differences were found in survival (P = .805, P = .793, respectively), reoperation (P = .179, P = .973, respectively), structural valve deterioration (P = .639, P = .982, respectively), or any other functional or clinical endpoints when patients were stratified by valve type (tricuspid aortic valve vs bicuspid aortic valve) or associated connective tissue disorder. At the latest echocardiographic follow-up (95% complete), 202 patients (94.8%) had none or trace aortic regurgitation, 10 (4.7%) mild, 0 had moderate to severe, and 1 (0.5%) had severe aortic regurgitation. Freedom from greater than 2+ aortic regurgitation at 10 years was 95.3% ± 2.5%. Six patients sustained acute type B aortic dissection (freedom at 10 years, 90.4% ± 5.0%).

CONCLUSIONS

Tirone David reimplantation valve-sparing aortic root replacement in carefully selected young patients was associated with excellent clinical and echocardiographic outcome in patients with either a tricuspid aortic valve or bicuspid aortic valve. No demonstrable adverse influence was found for Marfan syndrome or connective tissue disorder on durability, clinical outcome, or echocardiographic results.

Novel technique of valve-sparing aortic root replacement in two children younger than 3 years of age

A novel technique of valve-sparing aortic root replacement was applied to 2 children younger than 3 years of age with Marfan syndrome and large aortic root aneurysms. Using elements of both the remodeling and reimplantation techniques, circumferential rings from a 20-mm to 22-mm polyester graft provide stabilization at the subannular and sinotubular levels, and bovine pericardial patches create pseudosinuses. Follow-up at 2 years in 1 patient and 7 months in a second patient revealed satisfactory valve function with stable aortic root size.

First clinical results with the new sinus prosthesis used for valve-sparing aortic root replacement

OBJECTIVES

Sinuses of Valsalva are important in assuring the physiological function of the aortic valve. This study evaluates short-term clinical results of the reimplantation technique for aortic valve-sparing root replacement using a new prosthesis with three separate sinuses of Valsalva (sinus prosthesis).

METHODS

Between February 2009 and February 2011, a total of 23 patients (20 m/3 f; mean age 52 ± 14.8 years; range 24-70 years) with aortic root aneurysm underwent aortic valve-sparing procedures according to the David reimplantation technique using the new sinus prosthesis. Eighteen patients had tricuspid and five patients bicuspid aortic valves. All patients received clinical as well as echocardiographic examinations postoperatively (mean 13 ± 9.3 months; 0.3-28 months).

RESULTS

There was no death and no reoperation of the aortic valve. At latest follow-up, most patients were in New York Heart Association class I (n = 22; 95.7%). In 95.7% aortic valve regurgitation (AR) was 0 or 1+; one patient had AR 2+. Pressure gradients were between the normal range (mean pressure gradient 4.7 ± 1.9 mmHg). Echocardiographic images demonstrate physiological aortic root dimensions and configuration with three separate sinuses of Valsalva without systolic contact of leaflets to the wall.

CONCLUSIONS

The new sinus prosthesis provides near normal root geometry and hemodynamics in valve-sparing aortic root replacement using the reimplantation technique, applicable for tricuspid and also bicuspid aortic valves.

Expanding the indications for the David V aortic root replacement: early results

OBJECTIVE

To examine the early results of the David V valve-sparing aortic root replacement procedure in expanded, higher risk clinical scenarios with appropriately selected patients.

METHODS

From 2005 to 2011, 150 David V valve-sparing aortic root replacements were performed within Emory Healthcare. A total of 78 patients (expanded group) had undergone the David V in expanded, difficult clinical settings such as emergent type A dissection (n = 29), grade 3+ or greater aortic insufficiency (AI) (n = 53), or reoperative cardiac surgery (n = 14). These patients were evaluated and compared with a group of 72 patients (traditional group) with less than grade 3+ AI who underwent a David V in a traditional, elective setting. The mean follow-up was 19 months (range, 1-72), and the follow-up data were 88% complete.

RESULTS

There were 3 operative deaths (2.2%), all occurring in the expanded group. The overall patient survival at 6 years was 95%. Three patients required aortic valve replacement: two for severe AI and one for fungal endocarditis. Both groups had concomitant cusp repairs performed in conjunction with the David V (traditional, n = 10; and expanded, n = 16; P = .27). At follow-up, freedom from moderate AI was 93%, and the freedom from aortic valve replacement was 98%. No significant difference was observed in the freedom from moderate AI between the expanded and traditional groups (91% vs 95%, respectively; P = .16).

CONCLUSIONS

In selected patients possessing appropriate aortic cusp anatomy, the David V can be safely and effectively performed for the expanded indications of aortic dissection, severe AI, and reoperative cardiac surgery with low operative risk. Valve function has remained excellent in the short term, providing evidence of durability and a low rate of valve-related complications.

Evidence, lack of evidence, controversy, and debate in the provision and performance of the surgery of acute type A aortic dissection

Acute type A aortic dissection is a lethal condition requiring emergency surgery. It has diverse presentations, and the diagnosis can be missed or delayed. Once diagnosed, decisions with regard to initial management, transfer, appropriateness of surgery, timing of operation, and intervention for malperfusion complications are necessary. The goals of surgery are to save life by prevention of pericardial tamponade or intra-pericardial aortic rupture, to resect the primary entry tear, to correct or prevent any malperfusion and aortic valve regurgitation, and if possible to prevent late dissection-related complications in the proximal and downstream aorta. No randomized trials of treatment or techniques have ever been performed, and novel therapies-particularly with regard to extent of surgery-are being devised and implemented, but their role needs to be defined. Overall, except in highly specialized centers, surgical outcomes might be static, and there is abundant room for improvement. By highlighting difficulties and controversies in diagnosis, patient selection, and surgical therapy, our over-arching goal should be to enfranchise more patients for treatment and improve surgical outcomes.

Comparison of aortic root replacement in patients with Marfan syndrome

OBJECTIVES

Although the aortic-valve-sparing (AVS) reimplantation technique according to David has shown favorable durability results in mid-term and long-term studies, composite valve grafting (CVG) according to Bentall is still considered the standard procedure.

METHODS

Retrospectively, we evaluated the results of aortic root replacement of patients with Marfan syndrome (MFS) who underwent surgery between January 1995 and January 2010. MFS was diagnosed using the Ghent criteria. AVS was used in 58 patients and CVG in 30 patients with MFS. AVS was done for aortic-root aneurysm (n=48) or aortic dissection type A (n=10). CVG was used for aortic-root aneurysm in 14 patients or aortic dissection type A in 16 patients. The mean follow-up was 3.2 (95% CI: 2.4-4.2) years.

RESULTS

In both groups, 30-day mortality was 0%. Three patients (10.0%) in the CVG group required resternotomy for postoperative bleeding versus two patients (3.4%) in the AVS group (p=0.3). At follow-up, mortality was 10% in the CVG group versus 3.4% in the AVS group (p=0.3). Re-operation was required in two patients (3.4%) after AVS and in three patients after CVG (10%) (p=0.3). Three patients (10.0%) who underwent CVG had endocarditis and two patients (6.7%) had a stroke during follow-up, whereas no endocarditis and stroke occurred after AVS. After 14 years, stratified event-free survival was better in the AVS group (event-free survival was 82.3% vs 58.6%, log-rank test p=0.086), especially after aneurysm (p=0.057). After 10 years, freedom from aortic regurgitation ≥II° in the AVS group was 80% for aneurysm and 50% after dissection (p=0.524).

CONCLUSION

The reimplantation technique according to David was associated with excellent survival, good valve function and a low rate of re-operation, endocarditis, and stroke. There was a trend to better event-free survival for AVS patients making it the procedure of choice in MFS patients.

Advances in aortic valve repair: focus on functional approach, clinical outcomes, and central role of echocardiography

The surgical classification of aortic regurgitation (AR) is based on cusp mobility. Based on this classification, there are 3 classes of AR: type I is defined as normal cusp mobility, type II is defined as excessive cusp mobility, and type III is defined as restricted cusp mobility. Patients often have multiple coexisting mechanisms. Because aortic valve (AV) repair is safe, effective, and durable, it likely will become a mainstream surgical option for the management of significant AR, even in the setting of a bicuspid valve. Intraoperative transesophageal echocardiography has a central role at all stages in AV repair. Before cardiopulmonary bypass, it can accurately diagnose the mechanism of AR to guide operative strategy for successful repair. After separation from cardiopulmonary bypass, it can comprehensively evaluate the AV repair, including the likelihood that the repair will be durable in the long-term. Important echocardiographic predictors of a durable AV repair include the absence of AR, cusp coaptation above the annular plane, a coaptation length >4 mm, and an effective cusp height >8 mm. The clinical applicability of AV repair continues to expand and likely will evolve into a mainstream surgical therapy for AR, including minimally invasive techniques.

Early results of valve-sparing aortic root replacement in high-risk clinical scenarios

BACKGROUND

The feasibility of valve-sparing aortic root procedures (David) in certain high-risk situations has been questioned. We sought to determine the safety of the David procedure in the following high-risk subgroups: acute type A dissection, severe aortic insufficiency (AI), and reoperations.

METHODS

From 2005 through 2007, 110 root replacements were performed for the above criteria: 73 root replacements with a composite valve-conduit (Bentall) and 37 David procedures. The reimplantation technique was used in all 37 David patients, with 7 requiring aortic cusp repair.

RESULTS

There were no significant differences in preoperative or intraoperative variables between the groups, with the exception of cross-clamp time, which was longer for David patients. There was a slight, but nonsignificant increase in mortality among Bentall patients (8.2% [6 of 73]) compared with David patients (5.4% [2 of 37], p = 0.59]. There were no differences with respect to postoperative stroke, renal failure, or respiratory failure. Predischarge echocardiogram in the surviving 35 David patients demonstrated no AI in 25 patients and trace/mild AI in 10. Freedom from AVR at a mean follow-up of 8.8 months (range, 1 to 40) was 94.3% (33 of 35). One patient required AVR because of endocarditis at 9 months, and 1 had severe AI 13 months postoperatively.

CONCLUSIONS

Valve-sparing aortic root replacement can be performed safely in the setting of acute dissection, severe AI, and reoperations with acceptable early results. Long-term follow-up is needed to determine the durability of repair in these high-risk groups.

Thoracic aortic aneurysm syndrome in children

In contrast with adults, thoracic aortic aneurysms in children are usually associated with connective tissue defect syndromes. As such, there are phenotypic clues to identify patients at risk. Marfan syndrome, Loeys-Dietz syndrome, and bicuspid aortic valve syndrome account for the majority of these aneurysms. Indications for surgery as well as surgical options differ according to diagnosis and are reviewed herein.

Acute aortic dissection

We summarise advances in the epidemiology, presentation, pathogenesis, diagnosis, and management of acute aortic dissection. Improved understanding of this problem has been assisted not only by establishment of an international registry but also by progress in molecular biology and genetics of connective-tissue diseases. Advances in endovascular products and techniques have provided new treatment options. Open surgical repair remains the main treatment for dissection in the ascending aorta, whereas endovascular treatment is increasingly being used in dissection that is limited to other parts of the aorta.

Therapy of Marfan Syndrome

Marfan syndrome is a common inherited disorder of connective tissue caused by deficiency of the matrix protein fibrillin-1. Effective surgical therapy for the most life-threatening manifestation, aortic root aneurysm, has led to a nearly normal lifespan for affected individuals who are appropriately recognized and treated. Traditional medical therapies, such as beta-adrenergic receptor blockade, are used to slow pathologic aortic growth and decrease the risk of aortic dissection by decreasing hemodynamic stress. New insights regarding the pathogenesis of Marfan syndrome have developed from investigation of murine models of this disorder. Fibrillin-1 deficiency is associated with excess signaling by transforming growth factor beta (TGFbeta). TGFbeta antagonists have shown great success in improving or preventing several manifestations of Marfan syndrome in these mice, including aortic aneurysm. These results highlight the potential for development of targeted therapies based on discovery of disease genes and interrogation of pathogenesis in murine models.