External Scaffold for Strengthening the Pulmonary Autograft in the Ross Procedure

Despite offering several potential benefits over standard prosthetic aortic valve replacement, the use of the pulmonary autograft has been limited to date due to concerns over the risk of pulmonary autograft expansion and the need for reintervention. Several techniques using materials with biomimetic potential have been developed to reduce this complication. The incidence, risk factors, and pathophysiology of pulmonary autograft dilatation are discussed in this article. This seminar will provide an overview of the techniques of external pulmonary autograft support and their advantages and limitations. It also considers future directions for further investigation and future clinical applications of external pulmonary autograft support. Dilatation of the autograft is more likely to occur in patients with aortic regurgitation and a dilated aortic annulus. External scaffolding may prevent autograft stretching and expansion in these specific cases. However, from a biomimetic point of view, any permanent scaffold potentially restricts the movement of the autograft root. This reduces some of the benefits associated with the use of autologous tissue, which is the priority of the Ross procedure. To address this issue, several bioresorbable matrices could be used to support the root during its initial adaptive phase. Control of blood pressure with aggressive therapy is the first line to avoid this problem in the first year after pulmonary autograft implantation, together with support of the annular and sinotubular junction in some selected cases. This is the best way to maintain stable autograft root dimensions while preserving root dynamics. However, to determine the efficacy of this combined external support and best medical management, it is important to perform regular imaging and clinical follow-up.

Cabrol procedure and its modifications: a systematic review and meta-analysis

BACKGROUND

The Cabrol procedure has undergone various modifications and developments since its invention. However, there is a notable gap in the literature regarding meta-analyses assessing it.

METHODS

A systematic review and meta-analysis was conducted to evaluate the effectiveness and long-term outcomes of the Cabrol procedure and its modifications. Pooling was conducted using random effects model. Outcome events were reported as linearized occurrence rates (percentage per patient-year) with 95% confidence intervals.

RESULTS

A total of 14 studies involving 833 patients (mean age: 50.8 years; 68.0% male) were included in this meta-analysis. The pooled all-cause early mortality was 9.0% (66 patients), and the combined rate of reoperation due to bleeding was 4.9% (17 patients). During the average 4.4-year follow-up (3,727.3 patient-years), the annual occurrence rates (linearized) for complications were as follows: 3.63% (2.79-4.73) for late mortality, 0.64% (0.35-1.16) for aortic root reoperation, 0.57% (0.25-1.31) for hemorrhage events, 0.66% (0.16-2.74) for thromboembolism, 0.60% (0.29-1.26) for endocarditis, 2.32% (1.04-5.16) for major valve-related adverse events, and 0.58% (0.34-1.00) for Cabrol-related coronary graft complications.

CONCLUSION

This systematic review provides evidence that the outcomes of the Cabrol procedure and its modifications are acceptable in terms of mortality, reoperation, anticoagulation, and valve-related complications, especially in Cabrol-related coronary graft complications. Notably, the majority of Cabrol procedures were performed in reoperations and complex cases. Furthermore, the design and anastomosis of the Dacron interposition graft for coronary reimplantation, considering natural anatomy and physiological hemodynamics, may promise future advancements in this field.

Matched comparison between external aortic root support and valve-sparing root replacement

OBJECTIVES

Differences in indication and technique make a randomised comparison between valve-sparing root replacement (VSRR) and personalised external aortic root support (PEARS) challenging. We performed a propensity score (PS)-matched comparison of PEARS and VSRR for syndromic root aneurysm.

METHODS

Patients in the PEARS 200 Database and Aortic Valve Insufficiency and ascending aorta Aneurysm InternATiOnal Registry (undergoing VSRR) with connective tissue disease operated electively for root aneurysm <60 mm with aortic regurgitation (AR) <1/4 were included. Using a PS analysis, 80 patients in each cohort were matched. Survival, freedom from reintervention and from AR ≥2/4 were estimated using a Kaplan-Meier analysis.

RESULTS

Median follow-up was 25 and 55 months for 159 PEARS and 142 VSRR patients. Seven (4.4%) patients undergoing PEARS required an intervention for coronary injury or impingement, resulting in one death (0.6%). After VSRR, there were no early deaths, 10 (7%) reinterventions for bleeding and 1 coronary intervention. Survival for matched cohorts at 5 years was similar (PEARS 98% vs VSRR 99%, p=0.99). There was no difference in freedom from valve or ascending aortic/arch reintervention between matched groups. Freedom from AR ≥2/4 at 5 years in the matched cohorts was 97% for PEARS vs 92% for VSRR (p=0.55). There were no type A dissections.

CONCLUSIONS

VSRR and PEARS offer favourable mid-term survival, freedom from reintervention and preservation of valve function. Both treatments deserve their place in the surgical repertoire, depending on a patient's disease stage. This study is limited by its retrospective nature and different follow-ups in both cohorts.

Personalized external aortic root support in aneurysm disease

PURPOSE OF REVIEW

To bring together and annotate publications about personalised external aortic root support reported in the 18 months preceding submission.

RECENT FINDINGS

The total number of personalised external aortic root support (PEARS) operations is now approaching 700 in 30 centres in Australia, Belgium, Brazil, Czech Republic, Great Britain, Greece, Ireland, Malaysia, Netherlands, New Zealand, Poland and Slovakia. There are continued reports of stability of aortic dimensions and aortic valve function with the only exceptions known being where the surgeon has deviated from the instructions for use of the device. The median root diameter of Marfan patients having PEARS was 47 mm suggesting that the existing criterion of 50 mm is due for reconsideration. The peri-operative mortality currently estimated to be less than 0.3%. The first recipient remains alive and well after 18 years. The use of PEARS as an adjunct to the Ross operation to support the pulmonary autograft is being explored in several centres.

SUMMARY

The operation requires proctoring and adherence to a strict operative protocol and with those precautions excellent results are attained. The evidence and opinions provided in the cited publications indicate that PEARS is a proven and successful prophylactic operation for aortic root aneurysm.

Early Repair of Aortic Wall Structural Defect by "Net" Endoprosthesis to Arrest the Aneurysm without Interference with Aortic Branch Vessel Perfusion

Current treatments of aortic aneurysm include surgical or endovascular, respectively, anatomical or functional, substitution of the aneurysm tract; however, with these methods, perfusion of at least some collateral branches cannot be fully restored, leading to the risk of paraplegia. We present a novel endovascular “net” prosthesis to strengthen the aortic wall while preserving perfusion of collateral branches. This consists of a polyester mesh “net”-layered conduit in a variable cylindrical shape, which is personalized based on patient computed tomography scan images, and is defined by circular crossing spirals of a thin nitinol wire. The prosthetic conduit, shrunk by compressing the nitinol spirals, can be inserted into the vascular lumen and expanded in situ. Then, the insertion control device can be fully removed. Thus, the, “net” prosthesis, positioned inside the aorta in stable contact with the intimal wall for 2 to 5 months, is colonized by neointima and spontaneously moved deeper into the aortic wall in contact with the media, thus being ideally able to stabilize aortic diameter without interference with collateral branch blood perfusion. This new, (ideally) paraplegia-free procedure is aimed at curing the aortic wall structural defect, thus arresting the aneurysm from further progression. This contrasts with current treatments, indicated by aneurysm dimensions for their implied complication risk, which are actually for prophylaxis of impending rupture or dissection rather than fortification of the natural aorta. Moreover, this new approach can be used alongside open surgical procedures (personalized external aortic root support) as well as a frozen “net” elephant trunk technique, for full aortic stabilization.

The accuracy and reliability of 3D printed aortic templates: a comprehensive three-dimensional analysis

Background

Advances in 3D printing technology allow us to continually find new medical applications. One of them is 3D printing of aortic templates to guide vascular surgeons or interventional radiologists to create fenestrations in the stent-graft surface for the implantation procedure called fenestrated endovascular aortic aneurysm repair. It is believed that the use of 3D printing significantly improves the quality of modified fenestrated stent-grafts. However, the accuracy and reliability of personalized 3D printed models of aortic templates are not well established.

Methods

Thirteen 3D printed templates of the visceral aorta and sixteen of the aortic arch and their corresponding computer tomography of angiography images were included in this accuracy study. The 3D models were scanned in the same conditions on computed tomography (CT) and evaluated by three physicians experienced in vascular CT assessment. Model and patient CT measurements were performed at key landmarks to maintain quality for stent-graft modification, including side branches and aortic diameters. CT-scanned aortic templates were segmented, aligned with sourced patient data, and evaluated for the Hausdorff matrix. Next, Bland-Altman plots determined the degree of agreement.

Results

The Intraclass Correlation Coefficients values were more than 0.9 for all measurements of aortic diameters and aortic branches diameter in all landmark locations. Therefore, the reliability of the aortic templates was considered excellent. The Bland-Altman plots analysis indicated measurement biases of 0.05 to 0.47 for aortic arch templates and 0.06 to 0.38 for reno-visceral aortic templates. The arithmetic mean of Hausdorff's mean distances of the aortic arch templates was 0.47 mm (SD =0.06) and ranged from 0.34 to 0.58. The mean metrics for abdominal models was 0.24 mm (SD =0.03) and ranged from 0.21 to 0.31.

Conclusions

The printed models of 3D aortic templates are accurate and reliable, thus can be widely used in endovascular surgery and interventional radiology departments as aortic templates to guide the physician-modified fenestrated stent-graft fabrication.

Personalised external aortic root support for elective treatment of aortic root dilation in 200 patients

BACKGROUND AND OBJECTIVES

In personalised external aortic root support (PEARS), a custom-made, macroporous mesh is used to stabilise a dilated aortic root and prevent dissection, primarily in patients with genetically driven aortopathies. Data are needed on the safety and postoperative incidence of aortic events.

METHODS

We present a multicentre cohort study evaluating the first 200 consecutive patients (median age 33 years) undergoing surgery with an intention to perform PEARS for aortic root dilatation in 23 centres between 2004 and 2019. Perioperative outcomes were collected prospectively while clinical follow-up was retrieved retrospectively. Median follow-up was 21.2 months.

RESULTS

The main indication was Marfan syndrome (73.5%) and the most frequent concomitant procedure was mitral valve repair (10%). An intervention for myocardial ischaemia or coronary injury was needed in 11 patients, 1 case resulting in perioperative death. No ascending aortic dissections were observed in 596 documented postoperative patient years. Late reoperation was performed in 3 patients for operator failure to achieve complete mesh coverage. Among patients with at least mild aortic regurgitation (AR) preoperatively, 68% had no or trivial AR at follow-up.

CONCLUSIONS

This study represents the clinical history of the first 200 patients to undergo PEARS. To date, aortic dissection has not been observed in the restrained part of the aorta, yet long-term follow-up is needed to confirm the potential of PEARS to prevent dissection. While operative mortality is low, the reported coronary complications reflect the learning curve of aortic root surgery in patients with connective tissue disease. PEARS may stabilise or reduce aortic regurgitation.

Personalised external aortic root support (PEARS) to stabilise an aortic root aneurysm

Patients with congenitally determined aortic root aneurysms are at risk of aortic valve regurgitation, aortic dissection, rupture and death. Personalised external aortic root support (PEARS) may provide an alternative to aortic root replacement. This was a multi-centre, prospective cohort of all consecutive patients who received ExoVasc mesh implants for a dilated aortic root between 2004 and 2017. Baseline and peri-operative characteristics, as well as early postoperative outcomes are described, and time-related survival and re-operation free survival are estimated using the Kaplan-Meier method. From 2004 through 2017, 117 consecutive patients have received ExoVasc mesh implants for aortic root aneurysm. The inclusion criteria were an aortic root/sinus of Valsalva and ascending aorta with asymptomatic dilatation of between 40 and 50 mm in diameter in patients aged 16 years or more. Patients with more than mild aortic regurgitation were excluded. There was one early death. The length of stay was within seven days in 75% of patients. In conclusion, the operation achieves the objectives of valve-sparing root replacement. PEARS may be seen as a low-risk conservative operation, which can be applied earlier on in the disease process, and which is complementary to more invasive procedures, such as valve-sparing root replacement or total root replacement.

A review of pulmonary autograft external support in the Ross procedure

Introduction: Although the Ross procedure offers several advantages over standard prosthetic AVR, its use remains limited. The risk of pulmonary autograft dilatation requiring reintervention remains one of the main concerns. Consequently, multiple techniques have been developed in attempt to mitigate this complication.Areas covered: This article reviews the incidence of pulmonary autograft dilatation, its risk factors and pathophysiology. The techniques of external pulmonary autograft support are discussed along with their respective advantages and limitations. Finally, future areas of research and developments are examined.Expert opinion: The risk of autograft dilatation is mainly prevalent in patients with aortic regurgitation and a dilated aortic annulus. In these selected patients, an external support may prevent dilatation of the autograft. However, any permanent support potentially restricts autograft root motion, mitigating some of the advantages associated with the Ross procedure. A bioresorbable matrix that could support the root during its initial adaptative phase could alleviate this problem. In our opinion, aggressive blood pressure control during the first postoperative year along with annular and sino-tubular junction support in selected patients provides optimal stability of autograft root dimensions while preserving root dynamics. Serial imaging and clinical follow-up are necessary to define the role of these various strategies.

Living the heart in three dimensions: applications of 3D printing in CHD

Advances in biomedical engineering have led to three-dimensional (3D)-printed models being used for a broad range of different applications. Teaching medical personnel, communicating with patients and relatives, planning complex heart surgery, or designing new techniques for repair of CHD via cardiac catheterisation are now options available using patient-specific 3D-printed models. The management of CHD can be challenging owing to the wide spectrum of morphological conditions and the differences between patients. Direct visualisation and manipulation of the patients' individual anatomy has opened new horizons in personalised treatment, providing the possibility of performing the whole procedure in vitro beforehand, thus anticipating complications and possible outcomes. In this review, we discuss the workflow to implement 3D printing in clinical practice, the imaging modalities used for anatomical segmentation, the applications of this emerging technique in patients with structural heart disease, and its limitations and future directions.

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.

Modified sizing technique with newly designed tools to facilitate the valve sparing aortic root replacement "David" procedure with mid-term results

BACKGROUND

Valve sparing root replacement differs in specific points. The main target remains to achieve a perfect intraoperative result and long-term stability. We aimed in this study to present our modified sizing technique for valve-sparing "David" procedure and its mid-term results.

METHODS

We present a retrospective single-center study. A newly designed sizing ring in addition to triple-armed forceps (Trifeet®) was used to measure the proper size of the Valsalva® prosthesis for patients undergoing David-procedure. Primary endpoints are intraoperative aortic regurgitation (AR) and early postoperative outcomes. Secondary endpoints included freedom from aortic regurgitation or reoperation and overall mortality.

RESULTS

A total of 63 consecutive patients who underwent David procedure between 09/2012 and 12/2016 were evaluated. Mean age was 52±15 years and 76.2% were male. Moderate to severe aortic regurgitation was reported in 60 (95.2%) patients. Four (6.3%) patients presented with type-A aortic dissection, 20 (31.7%) patients had bicuspid and 3 (4.8%) had a unicuspid aortic valve, 2 (3.2%) patients had a prior aortic valve repair. Intraoperative echocardiography revealed no 34 (54%), trace 26 (41.2%) or moderate 3 (4.8%) AR. Stroke, myocardial infarction, and 30-day mortality occurred in 1 patient (1.6%). During follow-up 5 (7.9%) patients needed reoperation due to recurrent AR within a mean of 35±18 months. One could be re-repaired, and the other four underwent aortic valve replacement. A second patient died in the late follow-up.

CONCLUSIONS

Our modified sizing technique simplifies the "David-procedure" and allows to achieve a good intraoperative and mid-term results. However, these results have to be confirmed in a larger cohort with a long-term follow-up.

Applications of 3D printing in cardiovascular diseases

3D-printed models fabricated from CT, MRI, or echocardiography data provide the advantage of haptic feedback, direct manipulation, and enhanced understanding of cardiovascular anatomy and underlying pathologies. Reported applications of cardiovascular 3D printing span from diagnostic assistance and optimization of management algorithms in complex cardiovascular diseases, to planning and simulating surgical and interventional procedures. The technology has been used in practically the entire range of structural, valvular, and congenital heart diseases, and the added-value of 3D printing is established. Patient-specific implants and custom-made devices can be designed, produced, and tested, thus opening new horizons in personalized patient care and cardiovascular research. Physicians and trainees can better elucidate anatomical abnormalities with the use of 3D-printed models, and communication with patients is markedly improved. Cardiovascular 3D bioprinting and molecular 3D printing, although currently not translated into clinical practice, hold revolutionary potential. 3D printing is expected to have a broad influence in cardiovascular care, and will prove pivotal for the future generation of cardiovascular imagers and care providers. In this Review, we summarize the cardiovascular 3D printing workflow, from image acquisition to the generation of a hand-held model, and discuss the cardiovascular applications and the current status and future perspectives of cardiovascular 3D printing.

Republished review: Surgical management of aortic root disease in Marfan syndrome and other congenital disorders associated with aortic root aneurysms

Elective root replacement in Marfan syndrome has improved life expectancy in affected patients. Three forms of surgery are now available: total root replacement (TRR) with a valved conduit, valve sparing root replacement (VSRR) and personalised external aortic root support (PEARS) with a macroporous mesh sleeve. TRR can be performed irrespective of aortic dimensions and a mechanical replacement valve is a secure and near certain means of correcting aortic valve regurgitation but has thromboembolic and bleeding risks. VSRR offers freedom from anticoagulation and attendant risks of bleeding but reoperation for aortic regurgitation runs at 1.3% per annum. A prospective multi-institutional study has found this to be an underestimate of the true rate of valve-related adverse events. PEARS conserves the aortic root anatomy and optimises the chance of maintaining valve function but average follow-up is under 5 years and so the long-term results are yet to be determined. Patients are on average in their 30s and so the cumulative lifetime need for reoperation, and of any valve-related complications, are consequently substantial. With lowering surgical risk of prophylactic root replacement, the threshold for intervention has reduced progressively over 30 years to 4.5 cm and so an increasing number of patients who are not destined to have a dissection are now having root replacement. In evaluation of these three forms of surgery, the number needed to treat to prevent dissection and the balance of net benefit and harm in future patients must be considered.

Effect of personalized external aortic root support on aortic root motion and distension in Marfan syndrome patients

OBJECTIVE

Personalized external aortic root support (PEARS) is a novel surgical approach with the aim of stabilizing the aortic root size and decreasing risk of dissection in Marfan syndrome patients. A bespoke polymer mesh tailored to each patient's individual aorta shape is produced by modeling and then surgically implanted. The aim of this study is to assess the mechanical effects of PEARS on the aortic root systolic downward motion (an important determinant of aortic wall stress), aortic root distension and on the left ventricle (LV).

METHODS/RESULTS

A cohort of 27 Marfan patients had a prophylactic PEARS surgery between 2004 and 2012 with 24 having preoperative and follow-up cardiovascular magnetic resonance imaging studies. Systolic downward aortic root motion, aortic root distension, LV volumes/mass and mitral annular systolic excursion before the operation and in the latest follow-up were measured randomly and blinded. After a median follow-up of 50.5 (IQR 25.5-72) months following implantation of PEARS, systolic downward motion of aortic root was significantly decreased (12.6±3.6mm pre-operation vs 7.9±2.9mm latest follow-up, p<0.00001). There was a tendency for a decrease in systolic aortic root distension but this was not significant (median 4.5% vs 2%, p=0.35). There was no significant change in LV volumes, ejection fraction, mass and mitral annular systolic excursion in follow-up.

CONCLUSIONS

PEARS surgery decreases systolic downward aortic root motion which is an important determinant of longitudinal aortic wall stress. Aortic wall distension and Windkessel function are not significantly impaired in the follow-up after implantation of the mesh which is also supported by the lack of deterioration of LV volumes or mass.

Biomechanical properties of the Marfan's aortic root and ascending aorta before and after personalised external aortic root support surgery

Marfan syndrome is an inherited systemic connective tissue disease which may lead to aortic root disease causing dilatation, dissection and rupture of the aorta. The standard treatment is a major operation involving either an artificial valve and aorta or a complex valve repair. More recently, a personalised external aortic root support (PEARS) has been used to strengthen the aorta at an earlier stage of the disease avoiding risk of both rupture and major surgery. The aim of this study was to compare the stress and strain fields of the Marfan aortic root and ascending aorta before and after insertion of PEARS in order to understand its biomechanical implications. Finite element (FE) models were developed using patient-specific aortic geometries reconstructed from pre and post-PEARS magnetic resonance images in three Marfan patients. For the post-PEARS model, two scenarios were investigated-a bilayer model where PEARS and the aortic wall were treated as separate layers, and a single-layer model where PEARS was incorporated into the aortic wall. The wall and PEARS materials were assumed to be isotropic, incompressible and linearly elastic. A static load on the inner wall corresponding to the patients' pulse pressure was applied. Results from our FE models with patient-specific geometries show that peak aortic stresses and displacements before PEARS were located at the sinuses of Valsalva but following PEARS surgery, these peak values were shifted to the aortic arch, particularly at the interface between the supported and unsupported aorta. Further studies are required to assess the statistical significance of these findings and how PEARS compares with the standard treatment.

Surgical management of aortic root disease in Marfan syndrome and other congenital disorders associated with aortic root aneurysms

Elective root replacement in Marfan syndrome has improved life expectancy in affected patients. Three forms of surgery are now available: total root replacement (TRR) with a valved conduit, valve sparing root replacement (VSRR) and personalised external aortic root support (PEARS) with a macroporous mesh sleeve. TRR can be performed irrespective of aortic dimensions and a mechanical replacement valve is a secure and near certain means of correcting aortic valve regurgitation but has thromboembolic and bleeding risks. VSRR offers freedom from anticoagulation and attendant risks of bleeding but reoperation for aortic regurgitation runs at 1.3% per annum. A prospective multi-institutional study has found this to be an underestimate of the true rate of valve-related adverse events. PEARS conserves the aortic root anatomy and optimises the chance of maintaining valve function but average follow-up is under 5 years and so the long-term results are yet to be determined. Patients are on average in their 30s and so the cumulative lifetime need for reoperation, and of any valve-related complications, are consequently substantial. With lowering surgical risk of prophylactic root replacement, the threshold for intervention has reduced progressively over 30 years to 4.5 cm and so an increasing number of patients who are not destined to have a dissection are now having root replacement. In evaluation of these three forms of surgery, the number needed to treat to prevent dissection and the balance of net benefit and harm in future patients must be considered.

Personalised External Aortic Root Support (PEARS) Compared with Alternatives for People with Life-Threatening Genetically Determined Aneurysms of the Aortic Root

Personalised external aortic support was first proposed in 2000 by Tal Golesworthy, an engineer with familial Marfan syndrome and an aortic root aneurysm. After putting together a research and development team, and finding a surgeon to take on the challenge to join him in this innovative approach, he was central to the manufacture of the device, custom made for his own aorta. He was the patient for the ‘first in man’ operation in 2004. Ten years later he is well and 45 other people have had their own personalised device implanted. In this account, the stepwise record of proof of principle, comparative quantification of the surgical and perioperative requirements, 10 years of results, and development and research plans for the future are presented.

The evolution of surgical and medical treatment of aortic root aneurysm

Since first report of aortic root replacement in 1968, the surgical risk and long term outcome of patients with aortic root aneurysm have been continuously improving. In the last 30 years, the surgical approach is also evolving towards more valve conservation with prophylactical intervention at an earlier clinical stage. Translational research has also led to emerging surgical innovation and new drug therapy. Their efficacies are currently under vigorous clinical trials and evaluations.

Personalised external aortic root support (PEARS) in Marfan syndrome: analysis of 1-9 year outcomes by intention-to-treat in a cohort of the first 30 consecutive patients to receive a novel tissue and valve-conserving procedure, compared with the published results of aortic root replacement

OBJECTIVE

Among people with Marfan syndrome who have a typical aortic root aneurysm, dissection is a characteristic cause of premature death. To pre-empt Type A dissection, composite root replacement with a mechanical valve became the standard of care in the 1980s and 1990s. This is being superseded by valve-sparing aortic root replacement to avoid lifelong anticoagulation. In 2004, a total root and valve-sparing procedure, personalised external aortic support, was introduced. We report here results among the first 30 recipients.

METHODS

From cross-sectional digital images, the patient's own aorta is modelled by computer aided design and a replica is made in thermoplastic by rapid prototyping. On this, a personalised support of a macroporous polymer mesh is manufactured. The mesh is positioned around the aorta, closely applied from the aortoventricular junction to beyond the brachiocephalic artery. The operation is performed with a beating heart and usually without cardiopulmonary bypass.

RESULTS

Between 2004 and 2011, 30 patients, median age 28 years (IQR 20-44) had this operation and have been prospectively followed for 1.4-8.8 years by February 2013. During a total of 133 patient-years there were no deaths or cerebrovascular, aortic or valve-related events. These early outcomes are better than published results for the more radical extirpative root replacement operations.

CONCLUSIONS

The aortic valve, the root architecture, and the blood/endothelia interface are conserved. The perioperative burden is less and there has been freedom from aortic and valvular events. A prospective comparative study is planned.

External aortic root support: a histological and mechanical study in sheep

OBJECTIVES

Personalized external aortic root support has completed initial evaluation and has technology appraisal in the UK for patients with Marfan syndrome for use as an alternative to root replacement. Its long-term success in preventing aortic dissection remains uncertain. Here, we report a study in sheep to establish whether the externally supporting mesh, as used clinically, is biologically incorporated. The strength of the resulting mesh/artery composite has been tested.

METHODS

The carotid artery of growing sheep (n=6) was enclosed in a mesh sleeve made of a polymer, polyethylene terephthalate. After a predefined interval of 4-6 months, a length of the artery was excised, including the sleeved and unsleeved portions, and was stress tested and examined histologically.

RESULTS

One animal died of pneumonia 7 days after implantation. Comparing sleeved with normal segments, the overall thickness was increased and there was a fibrotic sheet in the periarterial space. The overall vessel wall architecture was preserved in all specimens. Although media thickness of ensleeved arteries was smaller and in one animal mild oedema was found in one quadrant of the outer part of the media. There was a significant increase in stiffness and maximum tensile strength of the supported segments compared with normal arterial tissue.

CONCLUSIONS

Polyethylene terephthalate mesh, as used for the external support of the dilated aortic root in Marfan syndrome, becomes incorporated in the periadventitial tissue of the carotid artery of sheep. Limited thinning of the media, without any signs of inflammation or medial necrosis, was visible. There was a significantly greater tensile strength in the carotid artery/mesh composite compared with the unsleeved carotid artery.

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.

Implantation of an individually computer-designed and manufactured external support for the Marfan aortic root

For the operation of 'personalized external aortic support' (PEARS), the dimensions of the individual patient's aorta are taken from the preoperative MRI or CT digital images. They are used in computer-aided design to make a three-dimensional computer image of the individual patient's aorta. A physical model of the patient's aorta is made of thermoplastic, using a standard engineering process of rapid prototyping. On this physical model is manufactured an external support made of a medical grade polymer fabric mesh with 0.7&emsp14;mm pore size. This fabric is placed around the ascending aorta from the aortoventricular junction to beyond the brachiocephalic artery. Follow-up is complete for the first 34 patients (June 2004 to November 2012) to a total of 127 patient-years. Since we submitted this paper, we have had an early death (the 34th patient) as a result of intraoperative injury to the left main coronary artery. The remaining 33 patients are alive and well from 3 to 103 months free from aortic, aortic valve or device-related events.

Aortic valve sparing operations: a review

Aortic valve sparing operations were developed to preserve the native aortic valve during surgery for aortic root aneurysm as well as surgery for ascending aortic aneurysms with associated aortic insufficiency. There are basically two types of aortic valve sparing oprations: remodeling of the aortic root and reimplantation of the aortic valve. These operations have been performed for over two decades and the clinical outcomes have been excellent in experienced hands. Although remodeling of the aortic root is physiologically superior to reimplantation of the aortic valve, long-term follow-up suggests that the latter is associated with lower risk of developing aortic insufficiency. Failure of remodeling of the aortic root is often due to dilatation of the aortic annulus. Thus, this type of aortic valve sparing should be reserved for older patients with ascending aortic aneurysm and normal aortic annulus whereas reimplantation of the aortic valve is more appropriate for young patients with inherited disorders that cause aortic root aneurysms. This article summarizes the published experience with these two operations. They are no longer experimental procedures and should be part of the surgical armamentarium to treat patients with aortic root aneurysm and ascending aortic aneurysms with associated aortic insufficiency.

External aortic root support for the Marfan aorta: anatomically normal coronary orifices imaged seven years after surgery

The occurrence of angina necessitated investigation of a patient seven years after an operation to protect his dilated Marfan aorta. The customized support, manufactured by a process of computer-aided design, had been fitted in May 2004 when the aortic root measured 49 mm. The magnetic resonance imaging appearances of the aorta remained unchanged over a postoperative period of 7 years and he remained completely well until he began to experience exercise-related angina in 2011. Coronary angiography showed the cause of angina to be an atherosclerotic left anterior descending coronary artery stenosis which was successfully stented. Aortography and coronary angiography performed at that time showed widely patent coronary orifices with no sign of impingement of the external support on the smooth lumen of his coronary arteries. The soft pliant nature of the textile from which the support was made, its intimate fit to the aorta and porous nature allowing incorporation into the aortic adventitia were deliberately built into the design. Nevertheless it was affirming to see these features realized on imaging seven years later. The patient is again completely well and angina free. He is one of a consecutive series of 30 patients who have had this device. There have been no device-related events in over 100 patient/years of follow-up, and all the patients remain alive and well.

A method for early evaluation of a recently introduced technology by deriving a comparative group from existing clinical data: a case study in external support of the Marfan aortic root

OBJECTIVE

During the early phase of evaluation of a new intervention, data exist for present practice. The authors propose a method of constructing a fair comparator group using these data. In this case study, the authors use the example of external aortic root support, a novel alternative to aortic root replacement.

DESIGN

A matched comparison group, of similar age, aortic size and aortic valve function to those having the novel intervention, was constructed, by minimization, from among patients having conventional aortic root replacement in other hospitals during the same time frame.

SETTING

Three cardiac surgical units in England.

PATIENTS

The first 20 patients, aged 16-58 years with aortic root diameters of 40-54 mm, having external support surgery were compared with 20 patients, aged 18-63 years and aortic root diameters of 38-58 mm, who had conventional aortic root replacement, between May 2004 and December 2009.

INTERVENTIONS

A pliant external mesh sleeve, customised by computer-aided design, encloses the whole of the ascending aorta. The comparator group had conventional aortic root replacement, 16 valve-sparing and four with composite valved grafts.

MAIN OUTCOME MEASURES

Duration of cardiopulmonary bypass (CPB), myocardial ischaemic time, blood loss and transfusion of blood, platelets and clotting factors.

RESULTS

Comparing total root replacement and customised aortic root support surgery: CPB (median (range)) was 134 (52-316) versus 0 (0-20) min; myocardial ischaemia 114 (41-250) versus 0 (0-0) min; 4 h blood loss was 218 (85-735) versus 50 (25-400) ml; and 9/18 had blood transfusion, 9/18 platelets and 12/18 fresh frozen plasma after root replacement versus 1/20, 0/20 and 0/20, respectively, for the novel surgery.

CONCLUSIONS

Avoidance or large reductions in CPB, myocardial ischaemia and blood product usage were achieved with the novel surgery. These data are of use in decision analysis and health economic evaluation and are available early in evaluation before randomised trial data are available.

Surgical management of patients with Marfan syndrome: evolution throughout the years

AIM

To evaluate the evolution of surgical management in a large population of patients with Marfan syndrome.

METHODS

This is a retrospective study of patients fulfilling the Ghent criteria for Marfan syndrome, who visited the Centre de référence national pour le syndrome de Marfan et apparentés and underwent a surgical event before or during follow-up in the centre.

RESULTS

One thousand and ninety-seven patients with Marfan syndrome, according to international criteria, came to the clinic between 1996 and 2010. Aortic surgery was performed in 249 patients (22.7%; 20 children and 229 adults), including the Bentall procedure in 140 patients (56%) and valve-sparing surgery in 88 patients (35%); a supracoronary graft was performed in 19 patients (7.6%), usually for aortic dissection. During the past 20 years, the predominant reason for aortic surgery has switched from aortic dissection to aortic dilatation, while age at surgery has tended to increase (from 32.4 ± 11.9 years to 35.2 ± 12.4 years; P=0.075). Mitral valve surgery was performed in 61 patients (5.6%; six children and 55 adults), including 37 valvuloplasties (60.6%) and 18 mitral valve replacements (29.5%). No significant difference was observed when comparing mitral valve surgery before and after 2000.

CONCLUSION

Surgery performed in patients with Marfan syndrome has switched from emergency surgery for aortic dissection to elective surgery for aortic dilatation; this is associated with surgery performed at an older age despite the indication for surgery having decreased from 60mm to 50mm. No significant evolution was observed for mitral valve surgery.

Aortic root aneurysm: principles of repair and long-term follow-up

OBJECTIVES

This study was undertaken to examine clinical and echocardiographic outcomes of aortic valve-sparing operations to treat aortic root aneurysms.

METHODS

From May 1988 to December 2007, a total of 228 patients underwent reimplantation of the aortic valve, and 61 underwent remodeling of the aortic root. Patients were followed up prospectively and had echocardiographic evaluation of valve function. Mean follow-up was 7.28 ± 4.33 years.

RESULTS

There were 5 operative and 26 late deaths. Survival at 12 years was 82.9 ± 3.7% and similar between types of operations. Age and aortic dissection were independent predictors of mortality. Seven patients have had reoperations on the aortic valve: 6 for aortic insufficiency and 1 for endocarditis. Five of these patients had undergone remodeling of the aortic root. Freedoms from reoperation at 12 years were 94.3% ± 2.6% among all patients, 90.4% ± 4.7% after remodeling, and 97.4% ± 2.2% after reimplantation (P = .09). Postoperatively, moderate aortic insufficiency developed in 14 patients (8 remodeling and 6 reimplantation) and severe aortic insufficiency in 5 (3 remodeling and 2 reimplantation). The remaining patients had mild, trace, or no aortic insufficiency. Freedoms from moderate or severe aortic insufficiency at 12 years were 86.8% ± 3.8% among all patients, 82.6% ± 6.2% after remodeling, and 91.0% ± 3.8% after reimplantation (P = .035). Only age-by 5-year increments-was an independent predictor of postoperative aortic insufficiency.

CONCLUSIONS

Aortic valve-sparing operations provide excellent patient survival and stable aortic valve function, particularly after reimplantation of the aortic valve.

External aortic root support for Marfan syndrome: early clinical results in the first 20 recipients with a bespoke implant

OBJECTIVES

Fatal aortic dissection occurs at young age in Marfan syndrome. Prevention relies on elective replacement of the aortic root. The placement of an external aortic root support, tailored to the anatomy of the individual patient has been proposed as a feasible alternative. DESIGN, SETTING AND MAIN OUTCOME MEASURES: External aortic root support was offered to patients with Marfan syndrome with aortic root diameter of 40-55 mm and without aortic regurgitation. By computer-aided design, a model of the individual patient's aorta was created from cardiac magnetic resonance images and a bespoke external aortic support was manufactured. Comparative measurements were made of the ascending aorta at the level of closure of the aortic valve cusps from magnetic resonance imaging studies taken preoperatively, at first follow-up, and at most recent follow-up. For patients having aortic root surgery at the same institution, in the same time frame as the first 10 patients, clinical data were retrieved on Marfan and other patients having aortic root replacement to serve as a reference data.

RESULTS

Twenty patients were operated upon from May 2004 to October 2009, 13 men and 7 women, median age 33 years. All 20 patients are alive and well at the time of last follow-up. Preoperative aortic diameters were 40-54 mm. All postoperative images were satisfactory with an overall reduction in aortic root dimensions. The surgery took half the time of other aortic root surgery. Cardiopulmonary bypass was used only in the first patient, myocardial ischemia was not required in any patient, and no postoperative anticoagulation is mandated.

CONCLUSIONS

The primary objective of this surgery was fully achieved in 19 of the 20 patients, reinforcing the ascending aorta while leaving the native aortic valve intact and conserving the blood/endothelium interface.