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COVER
STORY - July 2001 by Robert Carter Sidebar-
Yet a trend is developing to offer heart patients more options than bypass surgery and its long-time non-surgical alternative, angioplasty. Traditional bypass surgery corrects arterial flow problems by re-routing the blood supply past blocked arteries and through new ones grafted in place. These new arteries are created from the patient’s own tissues, either from the left mammary vein in the chest or one of the saphenous veins in the legs. A typical CABG involves 2.5 bypass grafts and requires a 4-to-6 week recovery, although as many as 90 per cent of patients can resume normal activities. CABG is major surgery, requiring the breaking of the breast bone, called sternotomy, and the use of the heart-lung machine to continue life while the patient’s own heart is stilled. Restarting the arrested heart is always a risk, as is the potential for post-operative infection. While CABG didn’t become a common procedure until 30 years ago, both Jewish Hospital in Louisville and St. Joseph’s in Lexington performed their first bypasses in 1965. Angioplasty, the standard alternative to the rigors of bypass surgery, was developed about 20 years ago. Jewish Hospital performed the first in Kentucky in 1981. A catheter is inserted in the saphenous vein in the leg and worked upwards to the blocked arteries around the heart with the guidance of a television monitor. At the blockage a balloon is inflated to 16 times normal atmospheric pressure and the impacting plaque is swept aside. In 80 per cent of angioplasties a tiny coil, called a stent, is placed in the cleared artery to hold it open. Angioplasty is normally about a 2-3-hour procedure and otherwise healthy patients can often leave the hospital the next day. The major risk is a clot that can lodge elsewhere in the body.
“Ablation is a cure, not just a treatment or diagnostic,” Dr. Mandrola stresses, with a success rate “in the high 90s” percent range. The cardiologist has performed 500 himself in the past four years. Cardiologists at both the St. Joseph’s Heart Institute and the Norton Hospital Heart Center, in Louisville, are now employing another new technique, vascular brachytherapy (VB), which received approval from the Food and Drug Administration in November 2000. VB is intended to correct a complication of angioplasty called in-stent restenosis where scar tissue froms around the stent and blocks the artery again. In-stent restenosis usually occurs within six months of the original angioplasty, if at all. Before VB, the only cure for restenosis was another angioplasty. Now with VB radioactive seeds are placed in the artery, again with a catheter, and burn away the new blockage permanently. St. Joseph’s is also using a “cutting balloon” to correct restenosis in small blood vessels. It is a low-pressure alternative to traditional angioplasty. All of these new procedures are considered “non-surgical.” Norton Heart Center is also a major locale for two minimally invasive surgeries – OPCAB and MIDCAB – which are designed to reduce the impact of traditional bypass grafting by eliminating the sternotomy and the heart-lung machine. OPCAB (Off Pump Coronary Artery Bypass) is employed when the patient requires treatment in several arteries at once. Surgeons access the heart through a small incision at the sternum but do not break the breastbone and do not stop the heart. MIDCAB (Minimally Invasive Coronary Artery Bypass) is similar but employed when the patient only needs one or two vessels bypassed. It involves a 2 to 3 inch incision through the rib cage. Both are intended for patients who are not good candidates for angioplasty, because of the severity of their blockages, or traditional bypass surgery, because of enlarged hearts, arrythmia or previous heart attack, according to Dr. William Dillon, also of Cardiovascular Associates in Louisville.
Dr. Dillon, also a practitioner of the VB procedure, calls the new techniques “exciting” and “good alternatives” to traditional bypass surgery. His colleague Dr. Mandrola says the same about the EP technique, citing it as an example of the “explosion of technology” in cardiovascular practice. Other examples of that explosion are being used at Central Baptist Hospital in Lexington to facilitate “sutureless” surgery. Two clamps, called the “Starfish” and the “Octopus,” hold and position the beating heart so surgeons may operate on the back side and also insert tiny metal staples that replace hand-sewn sutures. Normal suturing would be impossible while the heart is still beating. With the tools, surgery can be performed without the heart-lung machine, a particular advantage when operating on elderly patients. A stroke can occur whenever the surgeon attempts to graft age-weakened arteries or when the heart resumes pumping. The two clamps were designed by Medtronic, Inc., of Minneapolis, Minnesota, and only received FDA approval in early June. Central Baptist was the first in the state with the sutureless technique, although Jewish Hospital is planning to employ the two tools soon. Jewish Hospital was the site of an FDA clinical trial of a dramatic new device – the AbioCor Implantable Replacement Heart. The AbioCor, which actually consists of seven separate components, has been developed by Abiomed Inc., of Danvers, Massachusetts, and is to be applied in one patient at each of five participating hospitals in the U.S. The implant marked another first for the Jewish Hospital Heart and Lung Institute, which performed the first heart and heart-and-lung transplants in Kentucky (in 1984 and 1988) and the first minimally invasive procedure in the U.S. (in 1996).
According to David Lederman, PhD., co-founder of Abiomed, selected patients must be those who would have less than 30 days to live without the replacement and who would gain “a high therapeutic value” from the operation. He estimated the potential market at 125,000 units. The principal advantages of the AbioCor are the reduced chances of infection compared to earlier external artificial devices and the freedom from a lifetime of anti-rejection drugs necessitated by tissue heart transplants. Another technique called the Ross Procedure has come into vogue in recent years as the best possible treatment for one particular condition, ever since Dr. Ross first published the remarkable results of a 24-year study. Dr. Ross, a surgeon at Guy’s Hospital in London, was a pioneer in the field of autografting – using a patient’s own tissues to repair his own problem. Ross set out to correct one critical heart defect, aortic valve deficiency, in which the heart cannot process sufficient oxygen from the blood because the fluid flows too rapidly through the chamber. This condition is often apparent in childhood; affected children were once known as “blue babies.” Attempts had been made before Dr. Ross developed his namesake procedure in 1967 to use porcine or plastic valves to replace the defective one, but almost all failed over time as the patient grew. Dr. Ross’ innovation was to substitute the patient’s functioning pulmonary valve (the one leading out of the heart) for the deficient aortic value (the one leading in). Then, Dr. Ross could graft a porcine pulmonary valve to replace the one just relocated. This donor graft rarely failed because the stresses upon the pulmonary valve are considerably less than upon its twin – and the relocated autograft will grow as the patient does. In 1991 Dr. Ross published his results: 339 procedures with 80 per cent of the patients still living and 85 per cent not requiring any additional surgery. Two thousand Ross Procedures have been performed worldwide since, primarily on children and young adults. Dr. Robert Salley of St. Joseph’s has completed more than 120 himself, placing him in the top ten worldwide in the Official Registry of Ross Procedures maintained at Montana State University. “We support Dr. Salley and his team and the other, new exciting procedures because we believe in staying on the cutting edge for our patients – pun intended,” stresses Sohn, director of the Heart Institute. He explains that this level of support is expensive, costing St. Joseph’s about $1.6 million a year in foregone reimbursements. An additional problem is manpower, according to Dr. Mandrola, the cardiologist who employs the EP procedure. “These
new techniques are creating a tremendous demand and there
may not be enough specialists to meet it,” he warns.
Such heart procedures are a growth field, as the
population both expands and ages and the public becomes
more aware of alternatives. |
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Copyright 1996-2001, by Kentucky Business Online. All rights reserved. Editorial
content is copyright 2001, Lane Communications Group The Lane Report is a trademark of Lane Communications Group. All other trademarks are the property of their respective owners. |
Once a media event,
bypass surgery has almost become routine. Everyone knows
someone who has had one. Surgeons call it
“cabbage” – Coronary Artery Bypass
Grafting (CABG). It is the most common major surgery
performed in the U.S., 200,000 times a year. Not
surprising, perhaps, when you realize the U.S. records
900,000 deaths a year from coronary artery disease and
three million persons suffer chest pain, or angina
pectoris.
At Baptist East
Hospital in Louisville, Dr. John Mandrola and his
colleagues from Cardiovascular Associates PSC are now
using one of the new angioplasty alternatives
successfully. Electrophysiology, or EP, delivers a radio
frequency through the catheter to cauterize or ablate
small protusions in the heart muscle that can disrupt the
normal rhythm and trigger two serious conditions –
tachycardia, or rapid heart beat, and syncope, or
interrupted heart beat. Both can be life-threatening when
there are underlying conditions, according to Dr.
Mandrola. The technique is relatively painless and may
allow an otherwise healthy patient to leave the hospital
the same day.
The two procedures
have been in common use for about four years. Forty per
cent of the 1,700 bypass surgeries at St. Joseph’s
each year are now off pump, according to Douglas Sohn,
Director of its Heart Institute.
Co-principal
investigators and lead surgeons for Jewish in the
clinical field trial are Drs. Laman Gray, Jr., and Robert
Dowling, both members of the faculty at the University of
Louisville School of Medicine. The surgery involves
implanting a plastic pump to replace the selected
patient’s diseased heart, a battery and a controller
in the abdomen and a wireless receiver in the chest wall
to draw power from two external batteries and a wireless
transmitter that must be worn by the patient externally
in a harness. The internal battery will provide 30
minutes of emergency power while each rechargable
external battery will provide two hours of operation.