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 HeartPortÕs 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
WorldÕs 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 HeartPortÕs
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.