Aortic Root Enlargement Research Articles

Aortic valve replacement with pulmonary autograft in children and adults

Aortic valve replacement with a conventional prosthesis is still flawed with complications, especially in children and young adults. Complex aortic root enlargement (Konno) is often needed because of small aortic diameter. The poor compliance with anticoagulation by teenagers and the risks associated with this made us look at alternative techniques. From November 1990 to June 1994, 70 patients were considered for pulmonary autografts in our institution; 64 underwent the procedure with one death and one failure to implant. Short-term results are excellent, with minimal gradient in 90% and minimal regurgitation in 96% of the patients. The long-term follow-up, hopefully, will confirm the superiority of this procedure over more conventional replacement.

Stentless porcine aortic root: Valve of choice for the elderly patient with small aortic root?

The Medtronic Freestyle bioprosthesis is a stentless porcine aortic root cross-linked in dilute glutaraldehyde solution with stress-free fixation for the valve leaflets. It has been treated by a process in which amino oleic acid is used to reduce the potential for calcification. As a complete aortic root, it has the same versatility as the aortic homograft but has the advantage that it is readily available in all sizes to the implanting surgeon. Between January 1993 and May 1994, we implanted 64 Freestyle bioprostheses as aortic valve replacements using a freehand technique; 5 size 19 mm, 15 size 21 mm, 16 size 23 mm, 13 size 25 mm, and 15 size 27 mm valves were used. There were 35 men and the mean age was 75.7 years (64 to 84 years). The operative mortality was 3.1% (2/64). Echocardiograms at the time of discharge revealed mean aortic valve gradients ranging from 18.2 mm Hg for 19 mm to 10.3 mm Hg for 27 mm valves. Effective orifice areas ranged from 1.0 cm 2 for 19 mm to 2.0 cm 2 for 27 mm valves. No patient had more than trace aortic insufficiency. Our early experience with this new stentless bioprosthesis shows it to have excellent hemodynamics especially in the smaller valve sizes. Using this valve in patients who have a small aortic root and require a tissue valve avoids the need for aortic root enlargement procedures. (J T HORAC C ARDIOVASC S URG 1995;109:871-6)

Determinants of echocardiographic aortic root size. The Framingham Heart Study.

Previous studies that evaluated the determinants of aortic root size have not yielded uniform results. We examined the relations of age, height, weight, body surface area, sex, and blood pressure to echocardiographically determined aortic root size in a population-based cohort. The study sample consisted of 1849 men and 2152 women in the Framingham Heart Study and Framingham Offspring Study who were free of clinically apparent cardiac disease when echocardiography was performed. Aortic root measurements were made by M-mode echocardiography using a leading-edge-to-leading-edge technique. The relations of age, height, weight, body surface area, and blood pressure variables (contemporary and those obtained 8 years before) to aortic root dimension were examined by use of sex-specific correlations and linear regression analyses. Age, height, weight, and sex emerged as the principal determinants of aortic root dimensions in adults (cumulative R2 = .2085 in men and .2327 in women). The additional effect of contemporary or previous blood pressure measures was small and revealed direct associations of aortic root dimension with mean arterial and diastolic blood pressures and inverse associations with pulse and systolic blood pressures. Previous blood pressure measurements did not contribute significantly to prediction of aortic root size once contemporary blood pressure variable entered the models. Results of regression analyses using a sex-pooled data set showed that on average, the aortic root measurement in women was 2.4 mm smaller than that of men of comparable age, height, and weight. Logistic regression was used to assess the likelihood of aortic root enlargement according to blood pressure levels. After adjustment for age, height, and weight, the odds ratio of aortic dilation for a 1-SD increment in systolic pressure was 0.70 (95% CI, 0.52 to 0.95) in men and 0.79 (95% CI, 0.60 to 1.04) in women; the odds ratio for a 1-SD increment in diastolic pressure was 1.22 (95% CI, 0.91 to 1.63) in men and 1.33 (95% CI, 1.01 to 1.73) in women. Age, height, weight, and sex emerged as the principal determinants of aortic root dimensions. The additional influences of blood pressure measurements were small; direct associations of aortic root dimensions with mean arterial and diastolic blood pressures and inverse associations with pulse and systolic blood pressures were observed. Additional prospective studies are needed to confirm these observations and to assess the impact of aortic root dimensions on the incidence of hypertension.

Selectivity in aortic root reconstruction.

Anatomical variations in aortic root pathology, including combinations of dissection, aneurysmal dilatation, annuloaortic ectasia, and valve disease, defy standardized repair and mandate application of various surgical reconstructions. To examine these techniques, and their influence on morbidity and mortality, we reviewed 53 consecutive patients undergoing aortic root procedures. Thirty-two patients underwent total root reconstruction. Of these, 21 underwent Bentall procedures, 9 had a modification thereof, and 2 underwent a Cabrol reconstruction. Less extensive pathology was corrected in 21 patients with a partial root reconstruction. These included aortic valve replacement (AVR) and a separate tube graft in 14 patients, AVR and primary aortic repair +/- wrapping in 4 individuals, and AVR and patch aortic root enlargement in 3 patients. Mean age was 53.2 years (range 20 to 79). Nearly 20% had undergone previous cardiac surgery and 7.5% were emergencies. Early mortality was 4%. Complications included dysrhythmias (48%), myocardial infarction (4%), stroke (4%), pneumonia (14%), and pancreatitis (2%). There were no reoperations for bleeding. Three late complications, one pseudoaneurysm and two perivalvular leaks, were successfully repaired. Late deaths (13.7%) were caused by congestive heart failure (3), myocardial infarction (MI) (1), cancer (1), stroke (1), and accidental fall (1). Kaplan-Meier analysis reveals 1-, 5-, and 10-year survivals of 98%, 81%, and 66%. Survival and mortality data did not differ between groups, and except for the incidence of atrial dysrhythmias, complication rates also were not significantly different. This series illustrates the need for and the successful application of a selective approach to aortic root reconstruction.

The new stentless aortic valve: clinical results of the first 100 patients.

From May 1990 to August 1993, 100 patients underwent aortic valve replacement using the stentless porcine aortic valve. There were 69 males and 31 females. The mean age was 36 (range 11-76) years. Of 70 patients under 40 years of age, 20 were less than 20 years old. Indications included rheumatic heart sequelae in 55 patients (first valve replacement), prosthetic failure in 20, endocarditis in 13, congenital aortic bicuspid valve in four, degenerative disease in four and senile calcified aortic valves in four. Twenty patients had aortic annular related pathology. There were 15 associated surgical procedures. Forty-three patients required aortic root enlargement. There were approximately equal numbers of patients in New York Heart Association (NYHA) functional classes III and IV. The hospital mortality rate was 6%; 14 patients who experienced hospital morbidity had a full recovery. Two late reoperations were performed in patients with primary valve endocarditis; their recovery was uneventful. Four late deaths were not valve related. Comparative echo Doppler analysis before and after operation demonstrated good improvement of left ventricular function in nearly all patients. The valve was competent in 96% of patients and the remainder displayed minor jets without haemodynamic significance. The valve coaptation was stable in all patients. Use of the stentless porcine aortic valve in this first 100 patients has provided excellent clinical results with a follow-up of 41 months. Further follow-up and close observation will be required to analyse the outcome of this new valve and procedure with time.

Replacement of the aortic valve with cryopreserved aortic allograft: the procedure of choice for young patients.

The results of replacement of the aortic valve with cryopreserved aortic allograft are reviewed. There were no operative deaths in 88 patients. Thromboembolism did not occur in any patient and no anticoagulant medications were used. Actuarial freedom from reoperation for any reason was 89%; for structural deterioration it was 93% at 7.5 years. Infection was cured in all patients with endocarditis. Aortic allografts may be inserted by: (1) 120 degrees rotation freehand technique; (2) intact noncoronary sinus freehand technique; (3) aortic root enlargement technique; and (4) aortic root replacement technique. Zero thromboembolism without anticoagulants, high rate of cure of endocarditis, and the versatility of the tissue with a variety of methods for insertion to rebuild and remodel the aortic root to provide normal hemodynamic characteristics make aortic allograft the device of choice for replacement of the aortic valve in young patients.

Radical aortic root enlargement in the infant and child.

Complex multilevel left ventricular outflow tract obstruction includes some of the more challenging problems in congenital cardiac reconstructive surgery. Preoperative studies must carefully delineate the level of obstruction that may be entirely below the aortic annulus (i.e., subaortic stenosis), at the level of the aortic annulus (i.e., aortic annular hypoplasia), may be related to valve leaflet obstruction due to rigid or fused valve leaflets (i.e., aortic valve stenosis), or may be at the level of the tips of the commissures of the aortic valve (i.e., supravalvar aortic stenosis). Frequently, variable contributions are present from all these potential levels of obstruction. An important underlying goal in planning surgical therapy should be preservation of the child's own aortic valve, whenever possible. Operative procedures should preserve growth potential and minimize the need for repeat surgical procedures. A number of surgical options that incorporate these goals will be described.

Severe calcification of a parietal pericardial patch used in an aortic root enlargement: Case report

Severe calcification of a parietal pericardial patch used in an aortic root enlargement: Case report

Influence of prosthesis size on change in left ventricular massfollowing aortic valve replacement

Current surgical practice regarding valve replacement has as its primary concern the appropriateness of tissue versus mechanical prostheses and perhaps lesser emphasis has been placed on the size of the device. Despite technical advances, which provide maximal valve orifice area in valve substitutes, small device implantation may be accomplished in the aortic root but not effectively relieve the obstructive nature of the original disease. We reviewed 39 patients who had undergone aortic valve replacement (AVR) for aortic stenosis (AS) and had preoperative and postoperative (6 months-3 years) echo measurements which permitted calculation of the left ventricular mass (LVM) and mass index (LVMI). The mean age for the 32 women and 7 men was 67.4 years (22-83). There were four groups as determined by prosthetic size and aortic root enlargement (ARE) or not. The majority of the prostheses were heterografts (26), and the others were tilting discs or bileaflet. There was no difference (P = ns) in preoperative NYHA class, cardiopulmonary bypass (CPB) time, cross-clamp time, associated procedures or complications among the four groups. Although all groups demonstrated a reduction in LVM and LVMI, there was a greater and equal mass and mass index reduction in patients receiving a 21 mm prosthesis or larger. Despite the refinements in artificial valve designs, the 19 mm size valves may not provide comparable reduction in LVM and LVMI following AVR for AS, and the aortic root enlargement permits a larger prosthetic implantation and greater potential for reduction in LVM and LVMI without an increase in the operative time or postoperative complications.

Elective replacement of the aortic root in Marfan's syndrome.

We offer elective aortic replacement ot those we regard as being at high risk. The aortic root dimension and its rate of increase are the best predictors we have. We regard 5.5 cm as the probable upper limit and we are inclined to advocate surgery at an earlier stage in high risk families and in women planning pregnancy. These operations are planned for a calculated gain in life expectancy and it would be reasonable for there to be a degree of centralisation of referral and development of surgical expertise. We use beta-blockade for life, both before and after surgery, in all patients with Marfan's syndrome with aortic root enlargement. The data on which these recommendations are based are incomplete and we can only hope that with an increasing number of carefully documented cases we will refine them and improve upon them in the future. The concept of a "forme fruste" or a "Marfanoid aorta" in the absence of the syndrome is highly questionable so the comments made apply only to patients with Marfan's syndrome--not to other forms of annuloaortic ectasia or other less well characterised forms of aortic root disease.

Clinical and hemodynamic evaluation of the 19-mm Carpentier-Edwards supraannular aortic valve

The clinical and hemodynamic performance of the 19-mm Carpentier-Edwards supraannular aortic valve is largely unknown compared with that of the larger valves. Over 4 years we implanted the 19-mm Carpentier-Edwards supraannular aortic valve into 21 patients (20 female) with a mean age of 75 ± 1.2 years (range, 59 to 86 years) and a mean body surface area of 1.6 ±0.03 m 2 (range, 1.3 to 1.7 m 2). There were four deaths, one operative and three late noncardiac deaths. Follow-up of the 17 survivors for a mean of 20 ±3.1 months (range, 2 to 42 months) demonstrated symptomatic improvement in all 17 (all are now in New York Heart Association functional class I or II). There were no valve-related complications and no patient required long-term anticoagulation. Doppler echocardiographic studies were used to assess the in vivo hemodynamic profile of the valve. Mean postoperative aortic valve gradient was 34.1 ±2.7 mm Hg (range, 19 to 52 mm Hg). Functional valve orifice area was 1.1 ±0.09 cm 2 (range, 0.6 to 1.8 cm 2). Mean cardiac output was 3.92 ±0.17 L/min (range, 3.2 to 5.1 L/min) with a mean cardiac index of 2.5 ±0.11 L · min −1 · m −2 (range, 2.1 to 3.2 L · min −1 · m −2). In conclusion, we have demonstrated that aortic valve replacement with the 19-mm Carpentier-Edwards supraannular aortic valve has a low operative mortality and offers major clinical benefits despite moderate transprosthetic gradients. This approach provides an alternative management strategy in elderly patients who would otherwise require low-profile mechanical valves or aortic root enlargement.

Association of aortic dilation with regurgitant, stenotic and functionally normal bicuspid aortic valves

To determine whether aortic root dilation associated with a bicuspid aortic valve occurs independently of valvular hemodynamic abnormality, aortic root dimensions were measured by two-dimensional echocardiogrsphy in 83 adults with a functionally normal (n = 19), mildly regurgitant (n = 26), severely regurgitant (n = 27) or stenotic (n = 11) bicuspid aortic valve and compared with findings in normal subjects matched for age and gender. Aortic root measurements were made at four levels: anulus, sinuses of Valsalva, supraaortic ridge and proximal ascending aorta. Seventy-one percent of patients with a bicuspid aortic valve were men.When compared with control subjects, all hemodynamic subgroups showed a significantly larger aortic root size at three levels: sinuses of Valsalva, supraaortic ridge and proximal ascending aorta (p < 0.05 to p < 0.001). The prevalence of aortic root enlargement among all hemodynamic subgroups ranged from 9% to 59% at the level of the anulus, 36% to 78% at the sinuses, 47% to 79% at the supraaortic ridge and 50% to 64% in the ascending aorta.Thus, there is a high prevalence of aortic root enlargement in patients with a bicuspid aortic valve that occurs irrespective of altered hemodynamics or age. These findings support the hypothesis that bicuspid aortic valve and aortic root dilation may reflect a common developmental defect.

Aortic Valve/Root Interactions in Porcine Hearts: Implications for Bioprosthetic Valve Sizing

The implantation of aortic allografts as well as stentless, freehand porcine xenograft valves requires proper sizing of the graft for the recipient aortic root. To visualize the aortic valve in motion and measure the cyclic expansion of the aortic root, we developed an isolated porcine heart model and a computerized three-dimensional reconstruction technique. Dynamic and static expansions of the aortic root were obtained from beating and arrested porcine hearts, and additional static expansions at varying pressures were measured from reconstructed three-dimensional models of valves obtained with high-resolution magnetic resonance imaging. Measurements of aortic root expansion have shown that it is highly dependent upon the pressures imposed on the heart. Although the aortic root expanded by only 5% between systolic pressures of 60 and 100 mmHg, the total expansion was up to 40% between rest and cyclic pressurizing to 100 mmHg. This data suggest that unstented xenograft valves should be sized 30% to 40% larger than the collapsed size of the recipient aorta. Proper sizing of valves on stents should also be attempted to reduce the large amount of leaflet redundancy that current stenting techniques produce.

Tanned xenograft pericardium for aortic root enlargement during aortic valve replacement

Tanned xenograft pericardium for aortic root enlargement during aortic valve replacement

Marfanoid Children

The clinical, cardiac, and echocardiographic test results of 20 children with marfanoid features are reviewed. Fifteen were diagnosed as having Marfan syndrome, two had "possible" Marfan syndrome, and three had other diagnoses. On first evaluation, eight patients with Marfan syndrome (53%) had mitral regurgitation and none had aortic regurgitation. Echocardiography showed aortic root enlargement in 12 (80%) of 15 patients and mitral valve prolapse in 12 (80%) of 15. None had a normal echocardiogram. At follow-up examination, one patient had developed aortic root enlargement, and one patient, mitral valve prolapse. Thus, although aortic root enlargement is usually present in early childhood in patients with Marfan syndrome, it is not considered specific because in this study it also occurred in one child with Alport's syndrome and in one with marfanoid features. Four patients with aortic root enlargement were treated with propranolol and their echocardiograms showed no further increase in the aortic root diameter for several years. We recommend echocardiography in the diagnosis and routine management of children in whom Marfan syndrome is suspected.

Open valvotomy for critical aortic stenosis in infancy.

Over a 5 year period open valvotomy was performed on 13 patients under the age of one year with critical aortic stenosis. All 13 survived operation. There were two late deaths--one 38 days after operation, associated with an unrelated neurosurgical procedure and the other 2 years 6 months after when aortic root enlargement and replacement of the aortic valve were performed. During this period two other infants presented with aortic stenosis. One, who was very ill before transfer, died before operation could be performed. The second patient had a hypoplastic left ventricle with a small mitral valve ring and was, therefore, considered to be part of a different subgroup. All the surviving children have been followed up (median length of follow up 2 years and 11 months, range 7 months-5 years). Left ventricular function, in terms of percentage systolic wall thickening, was shown to be significantly impaired in all age groups. Peak diastolic thinning was abnormal in those children aged from 3 to 5. The aortic valve gradient, as assessed by peak instantaneous continuous wave Doppler, was less than 40 mm Hg in five patients and between 40 and 70 mm Hg in seven patients. One patient, with appreciable restenosis, has undergone successful percutaneous balloon dilatation of the aortic valve.

A computerized system for video analysis of the aortic valve

A novel technique was developed to study the dynamic behavior of the porcine aortic valve in an isolated heart preparation. Under the control of a personal computer, a video frame grabber board continuously acquired and digitized images of the aortic valve, and an analog-to-digital (A/D) converter read four channels of physiological data (flow rate, aortic and ventricular pressure, and aortic root diameter). The valve was illuminated with a strobe light synchronized to fire at the field acquisition rate of the CCD video camera. Using the overlay bits in the video board, the measured parameters were super-imposed over the live video as graphical tracing, and the resultant composite images were recorded on-line to video tape. The overlaying of the valve images with the graphical tracings of acquired data enabled the data tracings to be precisely synchronized with the video images of the aortic valve. This technique enabled us to observe the relationship between aortic root expansion and valve function.

Predictive Risk Factors for Periannular Extension of Native Valve Endocarditis: Clinical and Echocardiographic Analyses

The study objective is to identify clinical, microbiologic, and/or echocardiographic risk factors present early in the course of native valve endocarditis that predict subsequent development of periannular extension of infection. A multivariate computer-generated analysis of 21 clinical-microbiologic parameters and 11 two-dimensional echocardiographic parameters in patients with native valve endocarditis was designed. These parameters were statistically compared in operated-on patients with native valve endocarditis with and without periannular extension of infection. The study took place in a 600-bed acute-care, nonreferral, municipal hospital primarily servicing an indigent patient population. Seventy-three documented episodes of native valve endocarditis occurred between the years of 1973 and 1987, including 29 operated-on patients with surgically confirmed periannular extension of infection and 44 operated-on patients without periannular extension of infection. Multivariate logistic-regression analyses of multiple clinical, microbiologic, and echocardiographic parameters which are potentially predictive of eventual periannular extension of native valve endocarditis were carried out. The only two independent parameters that significantly predicted periannular infection among patients with native valve endocarditis were (1) aortic valve involvement and (2) abuse of intravenous (IV) drugs (p less than 0.01; p less than 0.01, respectively, multivariate analysis). The relative risk of developing periannular extension of endocarditis among patients with aortic valve involvement and/or IV drug abuse was increased by approximately 2.5-fold compared with patients without these characteristics. Factors not significantly associated with increased risk of periannular extension of native valve endocarditis included the following: prolonged febrile morbidity; Staphylococcus aureus etiology; or two-dimensional echocardiographic demonstration of vegetations, large vegetations (greater than or equal to 1 cm), multiple vegetations, or enlargement of aortic root or annulus. These data suggest that patients with native aortic valve endocarditis, particularly in the setting of IV drug abuse, should be considered for routine, serial noninvasive evaluation for the early detection of periannular extension of their infection.

Surgical management of children and young adults with marfan syndrome and pectus excavatum

Significant chest wall deformities occur in two thirds of children with Marfan syndrome (MS). The symptoms, physical findings, and surgical outcome of 11 patients with MS and severe pectus excavatum who required operative repair were reviewed. The diagnosis of MS was made before the pectus repair in six patients, at the time of evaluation of pectus in two patients, and after the repair in three patients. Symptoms included dyspnea upon exertion, tachypnea, and chest pain. Physical findings included aortic root enlargement or valvular disease, mitral valve disease, ligamentous disease, congestive heart failure, and ocular disease. All patients had severe pectus deformities with a narrow anteroposterior diameter in the midline, as well as a broad chest defect that extended bilaterally to the midclavicular line. The heart was shifted into the left side of the chest in all patients. A Ravitch-type pectus repair with a stainless steel substernal strut was used in eight patients, with one patient suffering a late recurrence; in three patients no strut was used, and all three had recurrence. There were no postoperative complications. In the postoperative follow-up of seven patients, symptomatic improvement of cardiopulmonary performance was noted. Four of the patients required subsequent open heart surgery, including replacement of the aortic valve in one patient, and composite grafts of the ascending aorta in three patients. Postoperative cardiac arrest was the only major open heart complication. All four patients recovered and did well after surgery, showing significant cardiac and pulmonary functional improvement.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamic and Angiographie Late Results Following Enlargement of Narrow Aortic Root Using Autologous Pericardium in Prosthetic Aortic Valve Replacement

From 1976 to 1984, 31 patients underwent enlargement of very small aortic roots using autologous pericardial strips the subannular part of which extended into the incised anterior mitral valve leaflet. The majority of these interventions (n = 24) were carried out before the end of 1980. Over an average follow-up period of 52.5 months, only one of the surviving patients had a complication traceable to the pericardial implantation (aneurysmatic patch dilatation), and 2 late deaths were also not directly connected with the type of surgical procedure. Objective findings for evaluating the hemodynamic status and behavior of the patch material were attained in a total of 14 patients by heart catheterization and angiography. Eleven patients were examined twice at an average of 2.5 months, and 11 at an average of 52.5 months. Eight of latter patients had undergone an early postoperative investigation. The hemodynamic results after prosthetic valve replacement and aortic annulus enlargement was satisfactory in those examined. No evidence could be found in any patient of disturbance of the mitral valve's function, paravalvular leakage at the aortic prosthesis, or obstruction of the left ventricular outflow tract caused by this operative technique. Progressive patch dilatation which had already been proved at the first examination was observed in one case. These results verify not only the efficiency of this technique for the enlargement of a small aortic root in the frame of prosthetic valve replacement, but especially the suitability of autologous pericardium as patch material for this purpose.