6. The Developing Venous System
Vitelline
Umbilical
Cardinal
Subcardinal
Supra cardinal
Supra-Subcardinal
Anastomosis
Sinus
Venosus
7.
8.
9. EMBRYOLOGY
Formed by vasculogenesis.
3 vital systemic venous drainage - VITELLINE/ UMBILICAL/ CARDINAL
SINUS VENOSUS - RIGHT AND LEFT HORNS - Provide bilateral
connection
The connection of 3 veins on left side regress- CORONARY SINUS
When sinus venosus fail to regress- Persistent left superior vena cava
10. Remodeling of Abdominal Venous System Occurs
through Obliteration of the Left Supracardinal Vein
11. Failure of Left Cardinal Veins to Undergo Normal
Regression Leads to Venous Anomalies
LSVC occurs in 0.3% to 0.5%
of the normal population
In 65% of cases, left
brachiocephalic vein is also
missing
4% of patients with CHD have
an LSVC
Usually drains to the coronary
sinus
13. TRIBUTARIES TO CORONARY SINUS
1. The Great Cardiac Vein (v. cordis magna; left coronary vein)
2. The Small Cardiac Vein (v. cordis parva; right coronary vein)
3. The Middle Cardiac Vein (v. cordis media)
.4. The Posterior Vein of the Left Ventricle (v. ventriculi sinistri)
5. The Oblique Vein of the Left Atrium(oblique vein of Marshall)
6. The Right Marginal vein
14. Brachiocephalic trunk
Lt. common carotid A.
Brachiocephalic veins
Lt. subclavian A.
Ligamentum arteriosum
Ascending aorta
Superior vena cava
Aortic arch
Pulmonary trunk
Left pulmonary
artery
Right coronary artery
Left
pulmonary
veins
Left coronary artery
Marginal artery
Small
cardiac vein
Circumflex artery
Great cardiac vein
Anterior interventricular
(left anterior descending)
artery
15.
16. Coronary sinus
Inferior vena cava
Lt. pulmonary
vein
Rt. Coronary A
Posterior cardiac
vein
Middle
cardiac
vein
Posterior
interventricular A.
Right
ventricle
Left ventricle
19. GREAT CARDIAC VEIN
The GCV curves to the left as it leaves the anterior interventricular
groove, to form the base of the triangle of
ââ Brocq and Mouchet â
Left anterior descending and the left circumïŹex arteries form other
sides.
GCV related internally to the anterolateral commissure of the mitral
valve.
The latter part lay in close relationship to the left circumïŹex artery
After crossing the left circumïŹex artery, the great cardiac vein ended
at the Vieussens valve and continued as the coronary sinus
20.
21. GREAT CARDIAC VEIN
Patent SVGs and
a patent LIMA to
the 1st diagonal
branch of the LAD.
.
Inadvertent
insertion of the
LIMA skip graft
into the Great
cardiac vein,
instead of the
distal LAD
22.
23. GREAT CARDIAC VEIN
Introducing the cardioplegic solution via the coronary
sinus will not perfuse the entire left side of the heart.
Post operatively there will be some myocardial
dysfunction due to non perfusion of the area drained
by Great cardiac vein.
Since the opening of the great cardiac vein in the right
atrium is very close to the interatrial septum it may be
mistaken as an atrial septal defect during cardiac
catheterization
24.
25. Selective arterialization of coronary
venous system
CVBG â Therapeutic option in patients with diffuse coronary artery
disease.
Arterial blood can perform retrograde perfusion through it and
nourish ischemic myocardium.
It helps to ensure sufficient blood flow, reduced thrombosis and
improved graft patency.
Another reason to select middle cardiac vein for arterialization was
that left coronary artery trunk or its branches may lie on the surface of
great cardiac vein for nearly 50% patients.
It means that, when coronary atherosclerosis happens, great cardiac
vein may be oppressed by sclerotic left coronary artery trunk or its
branches,
26. THEBESIAN VENOUS SYSTEM
In the absence of both
LSVC and a Coronary sinus
ostium in the left
atrium, drainage occurs
through enlarged Thebesian
veins.
Also, when hypoplastic
cardiac veins fail t o join t h
e coronary sinus, they
empty individually into the
atrial chambers through
dilated Thebesian channels
30. TRIANGLE OF KOCH
.
CORONARY SINUS DILATATION
1. Cardiac arrhythmia due
to stretching of the
atrioventricular node and
bundle of His.
2. Obstruction of the left
atrioventricular flow
because of partial occlusion
of the mitral valve.
a
31.
32. CORONARY SINUS
The coronary sinus is defined as the blood conduit that is a continuation of the great cardiac
vein from the valve of the great cardiac vein to the ostium of the coronary sinus.
The length varies from 3 to 5.5 cm. CS lies in the sulcus between the left atrium and ventricle
Begins proximally at the right atrial orifice and ends distally at the valve of Vieussen's.
.
The CS receives blood from the ventricular veins during ventricular systole and empties into the
right atrium during atrial systole.
The wall of the CS is made up of striated myocardium that is continuous with the atria, forming
a myocardial sleeve around the venous system
The Thebesian valve is a crescent shaped structure often found guarding the mouth of the CS
as it opens to the right atrium.
33. THEBESIAN VALVE
(1) absent, 14.7%;
(2) small and crescentric,
38%;
(3) large and covering the
entire orifice of the coronary
sinus, 30.7%;
(4) bars and bands, 5.3%;
(5) threads and networks,
5.3%;
(6) common Eustachian
and Thebesian valves,
34. RETROGRADE CARDIOPLEGIA
(1) the provision of a relatively uniform distribution of cardioplegia
even in the presence of severe coronary artery disease
2) it is effective in the presence of aortic regurgitation
(3) Redo â CABG antegrade cardioplegia is associated with a high
risk of atheromatous embolization from patent grafts
(4) RCP may be an effective method for treating coronary air
embolism
(5) it can be given without interrupting the surgical procedure.
35. Coronary Sinus ANOMALIES
An Absent coronary sinus is always
associated with a persistent left
superior vena cava (PLSVC)
connecting to the left atrium.
A Hypoplastic coronary sinus
occurs when one or more of the
cardiac veins drain directly into the
atria.
Atresia or stenosis of the coronary
sinus ostium may occur alone or with
associated cardiac anomalies
Enlargement of the coronary sinus
can be divided into two groups
- with left to right shunt
- without left to right shunt
Unroofed coronary sinus anomaly
36.
37. CORONARY SINUS ASD
Located â posteriorly and inferiorly in the interatrial septum.
INTERATRIAL SEPTAL TISSUE â separates AV valve
annulus.
May be associated SECUNDUM ASD.
CLEFT MITRAL VALVE- confluent PRIMUM ASD
PULMONARY VEINS â enter left atrium more superiorly than
usual â when LSVC present with coronary sinus ASD.
Left to right or right to left shunt depending on relative
ventricular compliance/ right atrial pressure.
38. Figure 1. Transesophageal echocardiography revealed both atrial and right ventricular
enlargement (left), a defect of the partial coronary sinus (middle), and shunt of the left atrium
to the dilated coronary sinus (right) at the near longitudinal plane.
41. REPAIR OF CORONARY SINUS ASD
Goal â separate systemic & pulmonary return
- eliminate shunting at atrial level
Caution â close to conduction system and pulmonary veins.
ROOFING PROCEDURE - BICAVAL VENOUS CANNULATION
- STANDARD RIGHT ATRIOTOMY
IF ATRIAL SEPTUM INTACT- FOSSA OVALIS IS INCISED
UNROOFED CS- MEDIAL TO PULMONARY VEINS
PERICARDIAL PATCH USED TO COVER THE DEFECT
ATRIAL SEPTUM REPAIRED EITHER PRIMARILY OR WITH
SECOND PERICARDIAL PATCH
42. UNROOFED CORONARY SINUS SYNDROME
LSVC to left atrium with coronary sinus ASD
LSVC to left atrium with COMMON ATRIUM
Complete unroofing without LSVC
Partial unroofing âmid portion without LSVC
Partial unroofing âdistal portion ,no LSVC
Partial unroofing âdistal portion ,intact
corsinus ostium with coronary sinus ASD
43. LSVC
PLSVC, is a result of a residual left
anterior cardinal vein.
It occurs in 0.1% to 0.3% of the
general population.
PLSVC is 3% to 8%, and up to 40%
when such patients have abnormal
situs
A PLSVC originates from the
junction of the left innominate vein
and the left jugular vein.
More than 90% of cases of PLSVC
drain through a coronary sinus.
44. The rest drain into the coronary sinus
through a window into the left atrium,
directly into the left atrium or into the
left pulmonary vein .
In 60% of cases, the innominate vein
bridges the two superior venae
cavae;
In the other 40%, the cavae drain the
right and left brachiocephalic regions
separately.
If there is no innominate vein the
PLSVC must persist; however, the
converse is not true.
A PLSVC with an absent right
superior vena cava is found in 14% of
cases
45. Questions to be asked
Is there a right superior
vena cava?
Is the Innominate
vein present
Is the PLSVC associated
with any other cardiac
malformations?
Where does the PLSVC
drain?
And does the surgery
involve the right atrium?
47. LSVC with CS Ostial atresia
Physiologically benign
Grave hazard- for cardiac surgeon if not identified
Permanent/temporary occlusion or vigorous
manipulation â cause myocardial congestion/ischemia
Patency should be sought â preoperatively/intraop
48. LSVC TO CS WITHOUT ATRESIA
If large left innominate vein is present â tourniquet.
Small/absent innominate veinCardiac catheterisation â occlusion pressure less than
18 mm hg- temporarily occluded.
Third angled venous cannula â cannulated directly
When temporarily occlusion not advisable
Flexible venous cannula retrograde through CS
Use of cardiotomy sucker.
Single right atrial venous cannula + profound
hypothermia and total circulatory arrest
49. LSVC TO LA without CS
LSVC can be ligated below innominate vein.
LSVC to RIGHT ATRIUM
- direct implantation
- left atrial tubular flap creation
- right atrial tubular extension
- PTFE graft
limitation â stenosis /occlusion of rerouted LSVC
50. COMMON ATRIUM
Repositioning the ATRIAL SEPTUM
-- Interatrial septum- completely excised
-- autologous pericardium/ prosthetic
patch used
Goal â systemic venous orifice lie on right side
- pulmonary venous orifice lie on left side
- optimal baffle placement
52. ATRIAL ISOMERISM
When b/l morphologically Right atria present
Lsvc enters the left sided Right atrium
Not an example of Unroofed coronary sinus.
Right isomerism â CS usually absent
Minor venous channel open directly into RA/RV
53. RAGHIB SYNDROME
INCLUDES â LSVC to left atrium
- Absence of coronary sinus
- Low lying ASD
Simple closure â Persistent desaturation
Correction - ASD repair + ligation of LSVC
- Excision of septum primum
- Placement of intra atrial baffle
54. HEART LUNG TRANSPLANT
Recipient LSVC is divided near its entrance
into left atrium during recipient cardiectomy
It is sutured end to end to donor left inominate
vein
SUPERIOR ROOFING â defect made in
interatrial septum
Superior wall of left atrium is used to make left
atrial tunnel from LSVC orifice to interatrial
defect
55. Cor Triatriatum
Pathogenesis - Impingement of a left superior
vena cava on the developing left atrium.
Left and right pulmonary veins may enter the
left atrium more superior than usual.
Mild to moderate narrowing- left atrium to which
pulmonary veins are attached.
56. Partially unroofed CS
condition can be easily overlooked
suspicious- when no asd or pulmonary vein
anomaly seen in RA with documented oxygen
step up
Diagnosis â pass a probe in CS orifice
- View defect through separate
incision in interatrial septum
FONTAN REPAIR - When it co exists with
tricuspid atresia â marked RIGHT to left shunt
that incorporates coronary sinus into systemic
venous pathway.
57. RECENT ADVANCES
Clinical trials investigating treatment with angiogenesis factors and gene therapy have been
goin on
New devices for creating cardiac arteriovenous fistulas percutaneously have been deviced
Radionuclide cardioangiography.
Three different systems of percutaneous mitral annuloplasty are currently under evaluation:
the Edwards Monarc system, the Carillon Mitral Contour System and the PTMA implant
system.
They are inserted into the coronary sinus and the great cardiac vein and all
work on the same principle: they shrink the mitral annulus, increasing leaflet coaptation and
thus reducing the regurgitation .
58. Take home message
Indications of selective CVBG include the patients with
tenuous right coronary artery or with diffuse lesions. It
is fit for the patients who need secondary CABG
operation.
Partially unroofed coronary sinus should not be
over looked
Close relation between LAD and GCV should
be kept in mind.