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Fistula

Congenital Sinus of Valsalva Aneurysm

1. Definition

A. a localized weakness of the wall of the sinus of Valsalva leads to focal bulging of the coronary sinus that may rupture into an adjacent cardiac chamber, creating an aortocardiac fistula. This is distinct from the diffuse dilitation of all sinuses seen in patients with connective tissue disorders (i.e., Marfan syndrome). These aneurysms are usually congenital but may follow, or lead to, bacterial endocarditis.

2. Morphology

A. Separation of aortic media of the sinus from the media adjacent to the hinge line of the aortic valve leaflet
B. This may be due to the absence of normal aortic elastic tissue and media in this region
C. Weak area gives way to aortic pressure to from the aneurysm
D. Excavation into underlying cardiac chamber, which may eventually rupture into an adjacent cardiac chamber
E. A windsock develops in some patients from elongation of the aneurysm
F. The aneurysm originates from the right sinus in 70%, the noncoronary sinus in 30%, and is rare from the left sinus
G. Asian patients have a more leftward position of the aneurysm
H. Rupture into the RV or RA is the most common; LA, LV, PA, and pericardial rupture are rare
I. There are important differences in the presentation between Western and Asian populations:
 WesternAsian
Right coronary sinus70%90%
RV termination70%85%
VSD incidence33%60%
Associated lesions50%5%

3. Associated anomalies

A. VSD
1) 30-50% of patients
2) Juxtaarterial (supracristal) - leftward right sinus; most common type
3) Juxtaaortic (perimembranous) - right 1/3 of right sinus
4) Hinge line of aortic leaflet separates aneurysm from VSD
B. Aortic valve abnormalities
1) about 20% of patients
2) AI secondary to prolapse usually associated with VSD
3) Bicuspid valve also occurs
C. Pulmonic stenosis
1) Usually subvalvular related to aneurysm in RVOT
2) May also be due to RVOTO developmental abnormality, such as TOF
D. Other lesions
1) Coarctation
2) PDA
3) ASD

4. Clinical Features and Diagnosis

A. Male predominance (80%)
B. Clinically silent lesion until rupture
C. 35% on rupture will have acute symptoms: precordial pain and breathlessness
D. 45% have gradual onset of dyspnea
E. 20% have no symptoms and are diagnosed by new murmur
F. Some patients have a latent period of weeks or years until signs of right heart failure develop
G. Severe symptoms are infrequent at time of rupture related to small size of fistula or VSD
H. Symptoms are worse if there is associated AI
I. Characteristic murmur (continuous) and wide pulse pressure
J. EKG = LVH, RBBB, CHB
K. Diagnosis easily made by echocardiogram; angiography useful to identify associated lesions

5. Natural History

A. Probability of aneurysmal rupture unknown
B. Rupture is most common in 3rd or 4th decade
C. Endocarditis is present in 10%, although unclear whether this causes the aneurysm or develops because of it
D. VSD associated with AI

6. Operative Technique

A. Unruptured - repair aneurysm by patch through aorta
B. Ruptured
1) Open both aorta and cardiac chamber to which fistula presents
3) Attach aortic valve hinge to patch to prevent prolapse
5) Repair aortic valve prolapse or replace aortic valve

7. Results

A. Risk of operation low (0-47%)
B. Risk of late death related to AI or AVR
C. Functional status 86% Class I
D. Reoperation more frequent if by direct suture than by patch closure