Port Access - Development

 

Spring 1996

 

Port Access Coronary Artery Bypass Surgery (PACABS). Most recent advance in Minimally Invasive Coronary Artery Bypass (MICAB) surgery. This attempts to combine the advantages of conventional Coronary Artery Bypass Graft (CABG) [including use of heart-lung machine and cardioplegia [stop heart] and MICAB. Using specially designed equipment inserted through multiple tiny incisions this avoids opening the chest wall. The CABG procedure is carried out under cardioplegic arrest using modified instruments to fashion the connection between the graft and coronary artery inside chest cavity through these tiny incisions.

 

The benefits stem from limited incisions used to access the heart. No bone is divided and very little muscle needs to be cut. With the heart stopped (and protected by cardioplegia) the anastomosis (junction of two vessels) can be made with precision and on a steady non-beating heart. It is possible to place grafts to diseased coronary arteries in any part of the heart using this method. Other methods allow operation to be performed on the heart endoscopically through tiny ports not just in the chest but also the groin where catheters are inserted. This allows the development of all heart bypass surgery not just the special case of single bypass procedures.

 

All of this avoids cracking the breastbone (sternum) - sternotomy - and spreading the ribs. This speeds recovery and decreases cost. For coronary bypass this will result in shorter hospital stays of 3 days from 6 days and a return to work in 1-2 weeks instead of 4-6 weeks. Surgeons used newly developed tools through 4 incisions (3 x one-half inch and 1 x three inch) in chest. System of catheters was also designed and threaded through blood vessels in the groin in order to stop the heart and allow the heart bypass machine to work in its place. Still in development is the stereomicroscope, which will allow greater visualisation and will replace the 3" incision with a smaller surgical port. The procedure uses video-endoscopy technology to partially remove a healthy mammary artery from within the chest (cut only one end) and grafted to a healthy portion of the affected coronary artery, bypassing the blockage and allowing blood to flow normally again.

 

October 29,1996

 

Minimally invasive heart surgery technique - Port-Access for single-graft coronary artery bypass and heart valve replacement and repair. FDA approved. Avoids splitting breastbone and operate endoscopically through several small incisions in the chest wall. Through "ports" between ribs, a catheter to heart delivers drug to stop its beat and a balloon that expands in the aorta and blocks blood flow. Heart-lung machine attached - far less invasive than traditional surgery - at the leg's femoral artery, rather than the heart, to take over body's circulation. For bypasses, surgeons take replacement artery from another part of body and sew it to the coronary artery below blockage, restoring blood flow to the heart. Single-graft currently but 12-18 months should be able to perform double- or triple-bypasses. Cardiac surgery at Johns Hopkins Medical Institutions also perform minimally invasive coronary artery bypass surgery through small incisions (for over a year - approx late 1995) but the heart continues to beat.

 

December 13,1996

 

Mitral valve replacement surgery by Port-Access. Minimally invasive technique. Arrest heart and place on cardiopulmonary bypass machine without cracking breastbone. CAB single-vessel disease. "Keyhole" surgery using mammary artery to perform bypass graft with still beating heart. Unique Endovascular Cardiopulmonary Bypass (EndoCPB©) supports Port-Access for valve replacement. Connection to heart-lung machine via special catheter guided to heart through blood vessels in neck and thigh. In traditional bypass aorta is clamped to shut off blood flow. In EndoCPB© same procedure with saline-filled balloon inflated inside aorta. Ability to stop and protect heart without the rigour of sternotomy. This is the paramount advancement to go beyond single-vessel bypass grafts. Now, even most complex heart surgery can be addressed less invasively.

 

Mitral valve replacement on 68 and 73 year old men successful. Out in two to three days. Mitral valve is "one way" door of blood flow from left atrium to left ventricle. Mitral valve malfunction may be a congenital (from or before birth) defect or caused by some underlying illness. Mitral valve currently only one possible by Port-Access but developing methods should change this. Already performing multiple vessel CABG by Port-Access. World's first triple vessel bypass surgery performed 5.12.96 at New York University Medical Centre.

 

February 19, 1997

 

Single-, double-, triple-bypass grafts, replacing aortic and mitral valves to repairing some aneurysms of the aorta - all by Port-Access. Surgeons everywhere are packing meeting rooms and watching teleconferences to learn about the techniques. HeartPort and CardioThoracic Systems have quite different methods. A total of 1.5 million heart surgeries and balloon angioplasties performed each year. Some 650,000 CABGs are done annually. Sternotomy is out. Port-Access is less traumatic, less expensive and shorter recovery times. Many surgeons not yet convinced that the benefits have been rigorously demonstrated. Some surgeons are using minimal incisions for repairs of the aorta, which is prone to developing aneurysms in the few inches near where it joins the heart. But now tailor incisions to suit the operation to be done. But there is no disagreement - the new methods have to prove themselves as safe and effective as the traditional techniques or they won't survive.

 

The conventional approach splits breastbone and pry open rib cage with retractors completely exposing the heart. Plastic tubing inserted into the large veins and arteries near heart carries blood to and from a heart-lung machine that takes over the heart's work while the pump-like organ is stopped, emptied of blood and repaired. After such intrusive surgery, takes time for body to recover. Some say pain is not too bad but others complain of severe pain from the incision, which can become infected and for weeks, and maybe months, have pain and tenderness throughout the rib cage. More worrisome is the risk of strokes. A small fraction suffer strokes following open-heart surgery perhaps because bits of hardened plaque are dislodged from inside the aorta as surgeons hook the patient up to the heart-lung machine.

 

Others have lost some mental functioning - usually temporary (see Memory Loss), apparently from the effects of the blood and ultimately the brain, of circulating the blood through the heart-lung machine for hours while the heart is "off-line". To minimise these risks some advocate doing without the heart-lung machine operating instead on the beating heart through a small incision. Proponents of the "beating heart" method say it's safer for the patient, though more difficult for the surgeon, who has to sew tiny stitches in a wriggling, moving coronary artery. But new instruments can virtually immobilise the artery while the heart beats. The "beating heart" method can only be used in single- or at most double-vessel on the front of the heart needs to be bypassed to improve blood flow. Despite this limitation CardioThoracic Systems believe the method will come to play a major role.

 

Although method can't be used for majority of bypass operations, which involve several vessels "hybrid" procedures will evolve. Minimally invasive "beating heart" surgery on vessels on the front of the heart and balloon angioplasty - non surgical method - for blockages on the back of the heart.

 

HeartPort have the opposite strategy - splitting the breastbone is the most traumatic part. Not the heart-lung bypass. HeartPort has developed a set of high-tech catheters that can be inserted through groin or neck to connect to heart-lung machine. Then, through small incisions in the chest (Port-Access), can operate on coronary vessels anywhere on the heart, which is stilled. Belief that use heart-lung machine fundamentally has a very good safety profile. Can be used in multiple-vessel bypass operations as well as valve operations.

 

Traditional "median sternotomy" won't disappear. It will continue to be used for more complex procedures and surgeries that involve both valve replacement and bypass grafting as an example. Also if complications develop the surgeon can always change to the conventional method. Sternotomy is a good and very safe incision.

 

March 20, 1997

 

First quadruple-vessel CABG with HeartPort's Port-Access minimally invasive cardiac surgery systems. Milestone major step forward in establishing feasibility and applicability of the Port-Access approach to highly complex heart surgery. Two small incisions in the chest enabling bypass of blocked arteries in each of the major vascular beds of the heart. Much faster recovery. Activity within several days vs several weeks after surgery. Reason for Port-Access method was this was a suitable case for this complex heart operation but also out of concern about post-operative breathing problems that might be aggravated by a median sternotomy. Pain associated with the sternotomy may give rise to breathing difficulties. This patient was a long-time smoker. Port-Access could result in an easier recovery.

 

Port-Access minimally invasive cardiac surgery enables complex heart operations such as quadruple-vessel CABG because it incorporates several minimally invasive technologies that replicate several aspects of open-chest surgery that have made it the gold standard for decades. Port-Access technology makes it possible for surgeons to place the patient on cardiopulmonary bypass (CPB) minimally invasive to support the patient's circulation during heart surgery. Once the patient is on CPB the heart can be stopped temporarily and safely as is done in conventional heart surgery. With heart stopped can manipulate and turn it to reach front, sides and back to re-establish blood flow to all three major vascular beds. As heart is stopped high degree of accuracy and precision is possible.

 

June 10, 1997 (reported)

 

In February faulty mitral valve diagnosed from 59 year old woman who became extremely short of breath - open heart surgery to replace it. Problem. Jehovah's Witness so no blood products can be used. Virtually bloodless Port-Access technique. Minimally invasive. Incidence of severe complications often reduced by eliminating sternotomy. EndoCPB© system allows stopping heart and protect it while safely maintaining on cardiopulmonary bypass during the heart surgery. Other minimally invasive cardiac surgical techniques include mitral valve surgery, coronary artery bypass surgery and an innovative minimally invasive aortic valve surgery. Surgery performed March 25, 1997.

 

July 2, 1997

 

Successful performance of first five-vessel CAB using HeartPort’s Port-Access(r) minimally invasive heart surgery systems. Patient (63 year old woman) discharged from hospital and returned home 3 days after surgery. Incision was 4.5" on side of chest between ribs, smaller than conventional 12-15" cut down middle of chest normally required for open-chest surgery. Bypass the five blocked heart arteries using same techniques as for open-chest procedure, including two saphenous vein graft (relating to or denoting either of the two large superficial veins in the leg) and one radial artery graft attached directly to aorta. The 3-day hospital stay significantly shorter than the usual week or more with traditional CABG open-chest surgery. Shows that complex multi-vessel heart bypass surgery can be done - the most common type using the HeartPort minimally invasive system as though operating in an open-chest situation.

 

The wide range of heart operations with the Port-Access minimally invasive cardiac surgery enables three-, four-, five-vessel CAB because it incorporates minimally invasive technology that replicates several aspects of open-chest heart surgery. Surgeons can place the patient on cardiopulmonary bypass (CPB) minimally invasive to support the circulation during heart surgery. Once on CPB the heart can be temporarily stopped (and safely) as is done in conventional heart surgery. Because heart is stopped, the heart can be manipulated to work the back and sides and re-establish blood flow to all major vascular beds - with high degree of precision and accuracy. Although a less drastic procedure it is still serious heart surgery with the potential for certain complications. Not all patients are suitable candidates for Port Access. Procedures are CABG and heart valve replacement and repair.

 

March 30, 1998

 

Port-Access minimally invasive multi-vessel CABG produce outcomes comparable to conventional open-chest cases. Also shows significant reduction in the incidence of new onset post-operative arrhythmias (abnormal rhythm of heart beat). Growing body of international data that demonstrate safety and efficacy of minimally invasive cardiac surgery. Lesser complications especially atrial fibrillation. The motionless, bloodless surgical field makes it possible to achieve complete coronary artery revascularisation using standard techniques including proximal anastomoses on the ascending aorta.

 

April 13, 1998

 

HeartPort releases two new products - Endocoronary Sinus catheter and Endoaortic Clamp catheter are crucial components of the cardiopulmonary bypass (EndoCPB©) system. New products have been engineered to decrease amount of time required to place patients on EndoCPB© and to simplify Port-Access surgery for the entire surgical team. Endocoronary Sinus catheter used to occlude coronary sinus, deliver retrograde cardioplegia and monitor coronary sinus pressure during Port Access procedures. Endoaortic Clamp used to occlude ascending aorta, vent the aortic root, deliver antegrade cardioplegia and allow monitoring of the aortic root and balloon pressures.

 

Over 4000 Port-Access procedures in 170 centres worldwide so far carried out. Port Access approach allows multi-vessel CABG, heart valve replacement and repair and congenital heart defect repair through "port" between ribs. Eliminates major chest incision.

 

June 9, 1998

 

World’s first minimally invasive computer-assisted heart surgery procedure. Performed in May in Paris, France and Leipzig, Germany. The Intuitive system uses state of the art computing and advanced robotics to control minimally invasive heart surgery with highly specialised micro-instruments with extreme precision. Uses also HeartPort’s Endovascular Cardiopulmonary Bypass (EndoCPB©) and other devices from its Port Access CAB and MVR systems. Minimally invasive heart procedure evolving rapidly whereby perform wide range of operations through smaller and smaller incision. One centimetre incisions using same hand movements as in open-chest surgery. High resolution 3D video image of surgical field. Translated hand movements to precise micro surgical movements of instruments at operative site. This makes minimally invasive surgery less invasive than it already is. Seeking FDA approval for general use in the USA.

 

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