Cardiovascular surgery for Marfan syndrome

Imaging of Genetic Thoracic Aortopathy

Aortopathy is a term most commonly used to describe a group of genetic diseases that predispose patients to an elevated risk of aortic events including aneurysm and acute aortic syndrome. Types of genetic aortopathy are classified as either heritable or congenital, with heritable thoracic aortic disease (HTAD) further subclassified into syndromic HTAD or nonsyndromic HTAD, the former of which is associated with specific phenotypic features. Radiologists may be the first physicians to encounter features of genetic aortopathy, either incidentally or at the time of an acute aortic event. Identifying patients with genetic aortopathy is of substantial importance to clinicians who manage thoracic aortic disease, because aortic diameter thresholds for surgical intervention are often lower than those for nongenetic aortopathy related to aging and hypertension. In addition, when reparative surgery is performed, the approach and extent of the repair may differ in patients with genetic aortopathy. The radiologist should also be familiar with competing diagnoses that can result in acute aortic events, mainly acquired inflammatory and noninflammatory thoracic aortic disease, because these conditions may be associated with increased risks of similar pathologic endpoints. Because many imaging and phenotypic features of various types of genetic aortopathy overlap, diagnosis and determination of appropriate follow-up recommendations can be challenging. A multidisciplinary approach with the use of imaging is often required and, once the diagnosis is made, imaging has additional importance because of the need for lifelong follow-up. ^©RSNA, 2022.

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.

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.

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) 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.

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.

Imaging of Marfan Syndrome: Multisystemic Manifestations

Marfan syndrome is an inherited multisystemic connective-tissue disease that is caused by a mutation of the fibrillin-1 gene. The syndrome is characterized by a wide range of clinical manifestations. Common cardiovascular manifestations, most of which are substantial contributors to mortality, include annuloaortic ectasia with or without aortic valve insufficiency, aortic dissection, aortic aneurysm, pulmonary artery dilatation, and mitral valve prolapse. Scoliosis, pectus excavatum and carinatum, arachnodactyly, and acetabular protrusion are common musculoskeletal manifestations. Dural ectasia is a characteristic central nervous system manifestation. In some patients with Marfan syndrome, there is also pulmonary and ocular involvement. Early identification and treatment of these conditions contribute to an improved quality of life and a life expectancy close to the average for the general population in the United States. Radiologists play a key role in the diagnosis of Marfan syndrome. Knowledge about the various manifestations of Marfan syndrome and awareness of their radiologic appearances permit a comprehensive diagnostic approach that allows better patient care.

Marfan's syndrome and the heart

In recent years, there have been many advances in the treatment of cardiac disease in children with Marfan's syndrome. Early diagnosis, meticulous echocardiographic follow-up and multidisciplinary assessment are essential. Medical treatment with beta-blockers is probably helpful in most children with aortic root dilatation. Research on TGFbeta signalling and the potential treatment role of TGFbeta antagonists may lead to exciting new treatments, but the results of clinical trials are awaited. In managing the cardiovascular complications of Marfan's syndrome, the paediatrician has to walk a difficult path. On the one hand, restrictive lifestyle advice and drugs may need to be prescribed, often in the context of a family history of major surgery or even sudden death. On the other hand, it is essential to encourage the often asymptomatic child to develop and mature as normally as possible.

Echocardiographic anatomy of ascending aorta dilatation: correlations with aortic valve morphology and function

BACKGROUND

Different anatomical forms of proximal aortic dilations associated with aortic valve disease can be distinguished by echocardiography. Differences in the anatomy could reflect different pathogeneses and need for different therapeutic approaches. The present study assessed the clinical features associated to each anatomical form, particularly focusing on the relations with valve morphology and function.

METHODS

Trans-thoracic and trans-esophageal echocardiography reports of 552 adult patients (mean age 60.4+/-12.8 years; 379 male) with mild to severe proximal aorta dilation were reviewed. The relationships between the anatomy of aorta dilatation (distinguished into "root type" dilatation, with maximal enlargement at the sinuses, and "mid-ascending type", with maximal diameter at the mid-ascending tract) and aortic valve morphology (tricuspid/bicuspid) and function (normal/stenosis/regurgitation) were assessed. The relations with other clinico-echocardiographic variables were also tested in univariate and multivariate analysis.

RESULTS

A "root type" dilatation was found in 4.9% tricuspid patients with stenosis, 32.3% with regurgitation, 22.5% with normal valve function (p=0.018). Dilatation prevailed at the mid-ascending tract in patients with bicuspid aortic valve, irrespective of valve function (stenotic: 92.9%, regurgitant: 87.9%, normal: 94.3%; p=0.23). Predominant root involvement was significantly more prevalent in male patients (24.8% versus 5.2% in females; p<0.001). In multivariate analysis, predominant aortic valve regurgitation (OR=1.83; p=0.028) independently predicted root site, while predominant aortic valve stenosis (OR=3.70; p=0.001), bicuspidity (OR=2.90; p=0.005) and female sex (OR=6.10; p<0.001) predicted mid-ascending site.

CONCLUSIONS

Pathogenetical considerations arise from the evidence of preferential mid-ascending localization of bicuspid-associated aortic dilatations. This finding is consistent with previous studies on bicuspid valve models revealing a wall stress overload beyond the sino-tubular ridge.

Aortic Valve Periprosthetic Leakage: Anatomic Observations and Surgical Results

BACKGROUND

One of the most frequent causes of reoperation after heart valve replacement is periprosthetic leakage (PPL). Previous studies have failed to determine whether PPL is linked to specific anatomic details. The aim of this study was to examine the location within the aortic annulus where PPL occurs, and to evaluate the postoperative outcome after surgical correction.

METHODS

Between January 1985 and December 2001, 28 patients underwent reoperation because of PPL after aortic valve replacement. The aortic annulus was analyzed in a clockwise format with hour 1 corresponding to the commissure between the left coronary sinus and the right coronary sinus, hour 5 to the commissure between the right coronary sinus and the noncoronary sinus, and hour 9 to the commissure between the noncoronary sinus and the left coronary sinus.

RESULTS

Overall operative mortality was 7.1% (2 patients). Repair of PPL was carried out in 8 patients whereas prosthetic valve replacement was necessary in 20 patients. Urgency or emergency operation (p < 0.0037), preoperative New York Heart Association class IV (p < 0.04), need for prosthetic valve replacement (p = 0.05), and implant of mechanical valve (p = 0.031) were independent determinants of dismal prognosis. Periprosthetic leakage occurred more frequently between hour 4 and hour 8 (19 patients), with the risk of leakage being two times greater than in other annular areas.

CONCLUSIONS

Our study suggests that PPL occurs more frequently in a specific portion of the peculiar aortic annulus. In case of PPL diagnosis, a timely reoperation might decrease operative risks by avoiding emergency procedures and unfavorable preoperative clinical conditions, and preventing prosthetic valve replacement.

Aortic insufficiency: defining the role of pharmacotherapy

Major advances in the diagnostic, evaluation, and particularly surgical treatment of aortic regurgitation (AR) have redefined the role of medical treatment. In acute AR, aortic valve replacement (AVR) is the only life-saving treatment. Medical treatment may improve the hemodynamic state temporarily before surgery. Rationale of medical treatment in chronic AR is based on the natural history and pathophysiology of the disease. The primary goal is to optimize the time of the AVR. If there is any symptom and/or left ventricular (LV) dysfunction, early AVR is required. Vasodilators should only be considered as a short-term treatment before surgery if there is evidence of severe heart failure or as a long-term treatment if AVR is contraindicated because of cardiac or noncardiac factors. In asymptomatic patients with severe chronic AR and normal LV function (even if the left ventricle is moderately dilated), vasodilators may prolong the compensated phase of chronic AR, although proof of their efficacy in delaying AVR is limited. Nifedipine is the best evidence-based treatment in this indication. ACE inhibitors are particularly useful for hypertensive patients with AR. beta-Adrenoceptor antagonists (beta-blockers) may be indicated to slow the rate of aortic dilatation and delay the need for surgery in patients with AR associated with aortic root disease. Furthermore, they may improve cardiac performance by reducing cardiac volume and LV mass in patients with impaired LV function after AVR for AR.

Interventional treatment methods in patients with Marfan Syndrome

Marfan syndrome is an autosomal dominant heritable connective tissue disorder which involves primarily the skeletal, ocular and cardiovascular system. The incidence of MS is on average 1: 10000 with 25-30% of cases caused by sporadic mutations.The leading cause of premature death in these patients is progressive dilatation and subsequent dissection of the ascending thoracic aorta resulting in cardiac tamponade, and left ventricular failure due to aortic regurgitation. Life expectancy is primarily determined by the severity of cardiovascular involvement, and has improved substantially over the last 20 years due to the advances in surgical and medical management.The optimum management of Marfan patients includes a lifelong surveillance with particular emphasis placed on aortic behaviour. Preventive replacement of various portions of the aorta has been a major contribution for improved life expectancy in these patients. The different surgical and interventional treatment options currently available will be further outlined in this review.

Current insights in diagnosis and management of the cardiovascular complications of Marfan's syndrome

Marfan's syndrome is an inherited disorder of connective tissue, caused by mutations in the fibrillin-1 gene located on chromosome 15. Diagnosis is still based on a combination of major and minor clinical features. Prognosis is mainly determined by the cardiovascular complications. Advances in surgical and medical treatment for these complications have dramatically improved the prognosis of the syndrome.