Posted in cardiac surgery, tagged cabg, lima graft, sequential lima graft, terminal lima branching on March 31, 2012| 1 Comment »
I recently came across an unusual LIMA arterial branching pattern .
Random thoughts
I need a surgeons Input here.
Posted in Cardiology - Clinical, Cardiology -Interventional -PCI, cardiology -Therapeutics, tagged BARI 2D, cabg, cabg vs PCI, cad, cass study, coroanry artery disease, courage study, medcial maangement vs pci, oat study on June 18, 2011| 2 Comments »
Coronary atherosclerosis is the number one killer of mankind. Many would consider it as an essential process of aging .Modern life styles and habits make this appear very early in life . There is currently an endemic (or even a pandemic ) of CAD due to premature atherosclerosis. We need to recognise CAD is not a primary heart disease .It is an irony, heart is an innocent bystander to the biological derangement of coronary vascular system when it is infested with atherosclerotic plaques .
So , when we are confronted with serious atherosclerotic lesions in a coronary artery what shall we do ?
We have three options
2 .Next method is to find the basic cause of terrorism , identify the perpetuates, facilitators and try to correct the root cause of it (CAD ) .This approach also refered to as medical management in cardiology community* . It aims at regression of plaque by statins, and life style modification and preventive cardiology. This modality is most ridiculed and insulted by the main stream cardiologists.
*Comparable to bilateral peace talks for a political solution to terror
3. And third option is a real surprise ! This neither confronts the lesion nor does it address the initiating factors . It just ignores the lesion and by pass it with a LIMA /SVG fly over , as if nothing has happened in this vital high way leaving the culprit scot-free .This option is executed by surgeons as CABG surgery . . . and for mysterious reasons this is a well accepted one .
CABG :Here the atherosclerotic burden is untouched by surgery . The graft can get diseased sooner or later , native vessel disease shall progress some times encroaching the ostia of distal graft site . Incidence of acute coronary syndrome following CABG is not greatly reduced for the simple reason we are not doing anything primarily to the inflamed plaques .These issues are left , to be taken care by the medical management .
* This article does not want to defame these great development in cardiology(PCI/CABG) . They have a specific role to play. CABG AND PCI remain the only option for critical lesions with limiting angina .But please remember without proper medical management ( ie Targeting the perpetuates of crime ) both PCI and CABG will be a big sham !
Final message
Avoiding the lesion or attacking the lesion is a primitive method to tackle CAD . Passifying the lesions in a slow and gentle manner, preventing further progression or regression of lesions is the only “sane” method for combating CAD . PCI and by pass surgeries can be termed as 21st century’s medical adventure sports which has limited role , in the overall control of CAD for the human kind .
And now answer this question . . .
Cardiologists attack the lesion and surgeon avoids the lesion ? Who is the winner in our fight against CAD ?
Both of them are clear losers .The winners are all those humble physicians and parmedical workers (or even the responsible lay public ) who help recognise the early forms of CAD and counsel properly to prevent it .
This is what Dean Ornish in 1991 documented in Lancet which was never considered scientific for the simple reason it has no commercial value !
Reference:
http://www.thelancet.it/journals/lancet/article/PII0140-6736(90)92230-F/fulltext
Posted in cardiac surgery, tagged cabg, left internal thoracic artery, LIMA grafting, lima to lad, rima, saphenaous graft CABG on June 2, 2011| Leave a Comment »
LIMA (Left internal mammary or thoracic ) is an unique artery , incidentally runs close to heart , has a privilege of supporting of human heart in its hour of crises ! . CABG surgery was started with saphenous grafts in 1967 . We have since moved on , from venous grafts to total arterial grafts . LIMA as a graft for coronary artery was a great innovation for cardiac surgery .Now , it can be stated ” CABG should not be done without a LIMA graft “
Advantages of LIMA
LIMA has good anatomical match for LAD. The 10 year patency rate is very favorable (60-80%) .LIMA is also a live graft enriched with nitric oxide , as it has native communication with subclavian artery .
Anatomy
The internal mammary artery originates from the under surface of the first portion of the subclavian, opposite the thyrocervical trunk. It descends behind the upper six ribs at a distance of about 1.25 cm. from the margin of the sternum, and at the level of the sixth intercostal space divides into the musculophrenic and superior epigastric arteries.
| The branches of the internal mammary are: | ||||||||||||
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There are few Anatomical issues for LIMA
Subclavian -LIMA ostial stenosis : Rare
Looping of LIMA is rarely an issue in hemodynamic point of view. But some believe a looped up LIMA is slightly prone for graft disease.Complex looping are reported rarely.
A loop and a early branch of LIMA : What is the implication ?
Abnormal or premature branching pattern of LIMA needs clipping as it may divert blood supply to LAD.Terminal branches can be used as a sequential graft to a branch of LAD usually a diagonal. In spite of all these issues , LIMA is rarely unsuitable either anatomically or physiologically .It is a safest vessel to graft.
Future of LIMA graft assessment.
Currently selective LIMA angiogram is the gold standard.
MDCT (64 slice) gives stunning images of LIMA graft , but unfortunately , it has little value for functional assessment .
Functional assessment of LIMA graft By angiographic frame count is being attempted in our institute.Will be reported in 2012.
Posted in cardiac surgery, Cardiology - Clinical, Cardiology -Interventional -PCI, cardiology -Therapeutics, Cardiology -unresolved questions, cardiology- coronary care, cardiology-ethics, tagged BARI 2D, cabg, chronic toal occlusion, coroanry collateral circulation, courage trial, ethics, heart, hippocrates, home collaterals, ischemic preconditioning, living with single coronary artery, medical management of cad, myths in cabg, myths in cardiology, nature power in cardiology, oat trial, ptca vs cabg, ramus intermedius, toat on March 26, 2011| Leave a Comment »
We are at the mercy of the three major coronary arteries (LAD,LCX,RCA) that sustain our life . Their job is clear cut .It has to perfuse about 300 Grams of live bundle of energy for an average of 6-7 decades.
What are the hurdles it faces , how it overcomes these obstacles forms the fascinating story of “survival of human heart”
When coronary blood supply is confronted with a sudden compromise as in ACS , often the heart has little time to respond . Hence the damage and risk of death is more. Even here there are lots of safety mechanisms and natural lytic process that limit the loss of life to less than 30 % of all STEMIs. This implies nature protects against the death in 70 % of individuals and help them to reach hospital.*
*Among those who reach hospital , we the cardiologists try to reduce the mortality to about 6-7 % (20% without treatment ) with all those hi-tech gadgets .It is a different story and will be addressed elsewhere .
When it comes to chronic insults , the heart has a unique potential to stage long haul battles. It has many tricks under its sleeves when challenged in a slow fashion.
The main weapons are two
1. Coronary collateral circulation.
2. Ischemic preconditioning.
Here is a patient who fights his life even after all his three coronary arteries totally blocked and surviving with one of the branches of left main -Ramus intermedius .
If you have thought his RCA was the savior you are mistaken .
To every one’s surprise his RCA was awful as well !
He had angina which was troublesome but manageable .Was able to live a life with acceptable standards (Indian standard ) After the angiogram he received CABG. A turbulent post operative course ensued due to various reasons . He struggled but fully recovered . . . and ultimately reached the previous standard of life !
Final message
Modern cardiology is all about not trusting powers of nature .
But youngsters should realise the enormous potential of those invisible powers.It may sound philosophical , but please remember . . .after all . . . philosophy is nothing but search for truths. Atleast believe in them once in a while !
Posted in Cardiology -Interventional -PCI, tagged cabg, circulation, complex pci, distal left main, double barrel stenting, europcr, India live coronary, interventional cardiology, jacc, left main stenting, live pci work shop, pci, proximaleft main, ptca, scai, tctmd, trifurcation lesion, unprotected left main on February 13, 2011| Leave a Comment »
*Is there a ready made two lumen stent available ?
The image is meant for concept purpose only !
It is one of the techniques available to stent unprotected left main
An excellent review in ACC intervention journal for unprotected left main .
Click on the Image to reach the article
Posted in cardiac surgery, Cardiology - Clinical, Cardiology -Interventional -PCI, cardiology -Therapeutics, Cardiology -unresolved questions, Echo library and gallery, echocardiography, myocardial disease, tagged acquired vsd, cabg, cardiogenic shock, catheter closure of vsr, dobutamine for vsr, free wall rupture, lad bypass in vsr, lvedp in vsr, mechanical complications of stemi, post infarct vsd, stable vsr, surgery for vsr, sutures give way in vsr, tissue friability in vsr, unstable vsr, ventricular septal rupture, vsr closure without cabg, vsr closure without coronary angiogram, vsr vs mr on January 14, 2011| 2 Comments »
We know, electrical deaths constitute the bulk of sudden cardiac deaths in MI. Mechanical deaths due to pump failure, muscle rupture , valve leak , also cause significant deaths .(Surprisingly many of the mechanical deaths may also fulfill the sudden death criteria !)
Free wall rupture is invariably a fatal event. Papillary muscle trunk rupture leads to severe LVF and unless intervened sure to result in fatality.
The ones who tear their interventricular septum are some what blessed ! Here , the rupture does not result in instant death as there is no loss of blood , instead , there is an volume over load of right ventricle followed by the left ventricle after a few beats. Hypotension is the rule. Even though this is a major complication there is something about VSR which makes it unique.
Sudden giving way of IVS has a decompressing effect on the ailing left ventricle.This many times bring a temporary relief to LV and if the patient survives the first few hour he is likely to stabilise further . In fact , sudden deaths within 24hours after the onset of VSR is an exception.This defect always gives the cardiologists and surgeon some time to plan the management. We need to use this time judiciously.
The natural history is delicate . Five themes are possible
* Pleasant themes occasionally witnessed !)
Here is 55 year old women came with extensive anterior MI with lower septal rupture.(She belonged to type 3 of the above scheme)
Note the septal rupture is visible even in 2D Echo
Color flow showing significant shunting from LV to RV.This shunt depends upon the LV contractile function, LVEDP and ofcourse the RV pressure
If there is severe RV dysfunction or bi ventricular dysfunction flow across the defect is inconspicuous.Brisk left to right shunting may be an indirect marker for good LV systolic function and absence of significant pulmonary hypertension.Both imply a better outcome.
The main determinant of survival is the underlying LV dysfunction and associated co morbidity(Renal function ) and complications .
Infero -posterior ruptures tend to be complex and may have multiple irregular tracks that makes it difficult to repair.
Investigations
Echo cardiogram is the mainstay .Serial echos should be done to assess the mechanical function and the progress of VSR.Hemodynamic monitoring may be done without injuring the patient .
Medical management
Surgeons role
Timing of surgery
Continues to be a controversy . Surgeons love to operate in a stable patient. But they need to realise , surgery is often needed to stabilise many patients. . The issue of tissue friability is blown out of proportion in the literature .When a life is is at danger we can not worry about friable tissues !
The rule of thumb could be
Surgical options
In our experience each of the above , has a role in a given patient depending upon the logistic , financial , social and even the available expertise. (A good surgeon in bad Institution !)
Is coronary angiogram mandatory before attempting to close VSR ?
Logically yes. If it is not available just do not bother . But, many times , when issue is saving lives , we can not afford to be too scientific , many lives have been saved by not following such strict protocols .A simple emergency thoracotomy and closure of rupture site (Without even touching the LAD ) can be a distinct and viable option in a selected few .
Role of cardiologists
Contrary to the popular belief the role of cardiologists is minimal , except to prepare the patient and hand over to the surgeon.
Interventional approach to close a VSR is currently be termed as an adventurous option ! The VSRs can assume unpredictable shapes and the tears can be multiple in different planes. The devices , catheters and other hard ware are not specifically made to tackle these issues .An acquired VSR should never be compared with congenital VSD.
Posted in Cardiology - Clinical, Cardiology -Interventional -PCI, cardiology -Therapeutics, cardiology- coronary care, Infrequently asked questions in cardiology (iFAQs), tagged angina relief, cabg, canadian cardiovascualr, cardiomyopathy, courage study, diastolic dysfunction, dilated cardiomyopathy, dyspnea, functional class, ischemic dcm, lv dysfunction, lv fucntion, nyha class 3, nyha class 4, oat study, pci, ptca, stable angina, toat study, unstable angina on December 30, 2009| Leave a Comment »
It is a well known fact , CABG and PCI provides immediate relief for patients with angina , which is refractory to medical therapy. Of course , this happens only if a critical occlusion of at least one epicardial coronary artery is opened . It need to be realised , angina due to microvascular disease can not be cured by maintaining epicardial patency .
While angina relief is prompt , dyspnea is not ! . If we believe, opening up a coronary artery in a patient with LV dysfunction will restore the LV function , it is grossly mistaken !
Why is it so ?
Angina relief requires simple restoration of oxygen supply and correction of local ischemia . This happens without any issue as the blood seeps in to the ischemic cells and soothes the ischemic nerve fibres that trigger the pain signals . While , for LV function to improve , the blood flow has to be converted to mechanical activity in the form of myocyte actin/myosin interaction. For this, there need to be an intact cellular contractile mechanism . The myocyte architecture should be appropriate .In post MI ventricles we know there is zig zag orientation of myofibrils due to myocyte slippage that interfere with mechanical recruitment . Further , integrity of extracellular matrix namely the collagen frame work is also vital . Note , angina relief is not concerned with any of the above .
And now , we also realise dyspnea in failing ventricles is vitally dependent on diastolic function , which is also very much impaired in ischemic DCM .There is little proof for PCI/CABG to correct the molecular mysteries in diastolic dysfunction !
Dysfunctional LV means what ? (read the link )
It is a collection of variety of myocardial tissues . Viz : Fully necrosed , partially necrosed , ischemic viable, non ischemic viable, ischemic non viable, non ischemic non viable , Apart from this patchy necrosis, patchy ischemic, areas are common. Finally , necrosed segments may also be perfused normally by spontaneous reopening of an IRA.
One can imagine the complexity of events in these segments once we do the PCI /CABG . The response is highly variable and unpredictable. The major concept we , the physicians believe or ( to be precise made to believe !) is the sanctity devoted to the viable myocardium .For many us , it is considered a holy exercise to identify viable myocardium in patients following MI and then revascularise them if found to have significant viable myocardium (Atleast 20% of infarcted area )
A full 2 decades were lost or (shall we say wasted on this futile exercise !) as we have since realised most of the cardiologists do not follow this rule .
Now , even a scarred myocardium is revascularised in the hope of recovery .As such , we have reached a stage where there is no contradiction for not doing a PCI /CABG with reference to LV dysfunction.
Now every patient with post MI LV dysfunction is considered to have some amount of viable myocardium that is fit enough for revascularization
Are we justified in doing this ?
Many clinical trials have revealed , the recovery of LV function in these segments has not been consistent at all .
The most surprising discovery is a viable myocardium need not be ischemic .It might get adequate blood supply either from invisible collaterals or trickle of antegrade flow . Hence an adequately perfused myocardial segment can still be non contractile . This shatters the myth that revascularisation must have a dramatic effect on the recovery of contractility in all viable segments.
The other major finding is , even ischemic viable myocardium ( documented by metabolic activities PET etc) need not regain it’s original contractility after the ischemia is fully corrected .
*reference for both the above statements are available from variety of sources including real life experiences .(Type C evidence )
Final message
Counter point
If the above statements are really true , How does PCI/CABG help relieving dyspnea and functional class what is your answer for thousands of patients with CAD and ischemic DCM who have greatly benefited from CABG ?
The answer could be simple , The revascularization piggybacks over the medical management (which , these patients pursue vigorously) like ACEI, statins, salt restriction, betablockers , optimal diuretics and tend to hijack the credits from the poor drugs !
Read a related blog
Posted in cardiac surgery, Cardiology - Clinical, Cardiology -Interventional -PCI, cardiology journal club, tagged beating heart surgery, Beware of beating heart CABG : It is minimally invasive and minimally effective !, cabg, cardiac surgery, cardio pulmonary bypass, cardiology journal club, jacc, LAD, lima graft, midcab, minimally invasive cardia surgery, nejm, obcab, off pump cabg, on pump cabg, RCA, rooby, rooby cabg study, svg graft on November 6, 2009| Leave a Comment »
The NEJM’s breaks the hidden truths about cardiopulmonary bypass in a beating heart. The irony in medical science is , trend setting land mark articles usually arrive very late . . . to disappoint all those patients who got the wrong treatment ! Off pump by pass is definitely one among them . . .
The major reason for off pump CABG’s s poor showing is
Click on the link to NEJM abstract ROOBY study
Posted in Uncategorized, tagged acc aha guidelines, acs, cabg, cath lab, chronic stable angina, cleaveland clinic, coronay revascularisation, courage trial, cypher stent, des, euoropct, flow limiting lesion, gruentzig, jacc, jama, left main disese, mayo clinic, nejm, nstemis, paclitaxel, pci, primary pci, proximal lad, ptca, ravel, scai, sirius, sirolimus, stemi, stent, stenting, syntax score, taxus, tct md, triple vesseldisease, wisdom trial on May 4, 2009| 1 Comment »
Scientifically , the indication for coronary revascularisation should be based on following
Practically ,
A CAD patient may fulfill “Any of the above 5 “ or “None of the above 5” , but , if a coronary obstruction was revealed by coronary angiogram and if he fulfils The 6th criteria , he becomes eligible for revascualrisation
If the patient has enough monetary resources (by self ) or by an insurance company to take care of PCI /CABG *
*The sixth criteria overrides all other criteria in many of the cath labs .Of course , there are few genuine ones still fighting hard , to keep the commerce out , from contaminating cardiology !
Dr.S.Venkatesan MD 
