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SSC – Perspectives On Medical Advances
Matthew Iain Stewart [090001931]
The Evolution of Surgery in the Treatment of Fallot’s Tetralogy
Introduction
“Any surgeon who would attempt an operation of the heart should lose the
respect of his colleagues”
T. H. Billroth 18931
Nowadays cardiac surgery is seen as a viable option to preserve and prolong
life. However in 1893 this view was not shared by many and rightly so. As at
that time, any “attempt” to operate on the heart would unquestionably result in
the death of a patient. An emphatic contradiction of the moral conduct to
“never do harm ”, as advocated within the original Hippocratic Oath.2 The
heart remained surgical taboo for a further fifty years, so what transpired over
the past seventy years to turn cardiac surgery from controversial killer to the
worldwide savior it is today? The potential of surgery and its advances were
unleashed by not only the confirmation of germ theory but also its acceptance,
the establishment of a blood transfusion service and the discovery of
antibiotics and anaethesia in the nineteenth century. This essay aims to
explore three of the four epochs in the development of cardiac surgery –
surgery on the heart’s major vessels, closed-heart surgery and open-heart
surgery – by highlighting the progression in the treatment of a common type of
heart defect in children called Fallot’s tetralogy.
The Four Epochs
It is useful to appreciate the anatomy of the heart and its role within the
circulatory system of the body as it is linked with how the development of
cardiac surgery was divided into its four epochs. The heart is composed of
two sets of chambers, the left atrium and ventricle aligned with the right atrium
and ventricle. The atria are located superiorly to the ventricles. The left side is
split from the right side by a thick wall of muscle called the septum. The basic
function of the heart is to pump oxygenated blood around the body. The right
side of the heart pumps venous blood (de-oxygenated blood) to the lungs to
become oxygenated and the left side pumps arterial blood (oxygenated blood)
to the body to be used in various reactions. Venous blood from the superior
and inferior parts of the body drains into the right atrium (RA) of the heart via
the superior and inferior vena cavae, respectively. From here the blood is
pumped through the tricuspid valve into the right ventricle (RV), it is then
propelled through the pulmonary valve into the pulmonary artery which divides
and enters each lung. In the lungs the blood is oxygenated and the carbon
dioxide removed and returned back to the heart through the pulmonary veins
into the left atrium (LA). The oxygenated blood is driven through the mitral
valve into the left ventricle where it is expelled through the aortic valve into the
aorta to be transported around the body.
Anatomy of the Heart & Blood
Circulation – the internal and external
structures of the heart and the flow of
blood within the heart (Diagram from
reference 3)
Interventricular Septum
Applying these anatomical principles, the evolution of cardiac surgery over the
past seventy years can be separated into four pivotal periods. During the first,
between the 1930’s and early 1940’s, the heart itself largely remained
untouched, however the large vessels rising from it were operated on to
provide palliative care caused by defects within the heart. The start of the
second epoch coincided with the conclusion of the Second World War in 1945
and ended in the 1950’s, as the force majeure of war impelled the medical
world to deliver advancements in blood transfusion, antibiotics and
antiseptics, which provided key components for closed-heart surgery. The
third epoch falls between the early 1950’s and early 1960’s, and includes the
pivotal event that allows the transmission from closed-heart surgery to openheart surgery, in the arrival of the pump. The fourth and final epoch of cardiac
surgery began in the late 1960’s with the first heart transplantation.
Fallot’s Tetralogy
Before analyzing the surgical techniques in the treatment of Fallot’s tetralogy,
it is important to address what defects are being corrected. This congenital
defect gains its namesake from the French physician Etienne Louis Fallot who
in 1888 described the following four irregularities.4 1. Right ventricular outflow
obstruction, where the pulmonary artery and valve is narrowed, 2. Overriding
aorta, where the aorta is shifted over the right ventricle and ventricular septal
defect instead of only the left ventricle, 3. Ventricular septal defect, a hole
between the right and left ventricle, 4. Right ventricular hypertrophy, an
enlargement of the muscular wall of the right ventricle.5 These lead to a
shunting of non-oxygenated blood through the hole in the ventricular septum,
resulting in the blood by-passing the lungs and preventing oxygenation. The
ultimate consequence is that the patient is centrally cyanosed and described
as having blue baby syndrome. Right ventricular outflow obstruction and the
ventricular septal defect are of particular clinical relevance as these
abnormalities are amenable to surgical correction.6
The First Epoch – Blalock/Taussig Operation
Helen Brooke Taussig was born in Cambridge, Massachusetts, in 1898.
Although a bright and promising student she was unrighteously rejected from
Harvard, her first choice medical school, as doors were still closed to women
at the time. She was accepted into the more liberal Boston University School
of Medicine, however she transferred to John Hopkins, acquiring her medical
degree in 1927. After completing a pediatric internship she was hired as the
director of a newly established cardiac clinic at her alma mater’s hospital. She
approached each case with a functional attitude, analyzing each pathological
abnormality on the principle of the changes in blood flow that ensues and the
clinical picture it triggers.7 Taussig noted that in children with a veno-arterial
intracardiac shunt, cyanosis was dependent on the pulmonary blood flow,
which can be measured using fluoroscopy8 (a technique for viewing real-time
moving images9). A decreased flow leads to a more profound cyanosis.10
More important was her experiences with the ductus arteriosus, a connection
between the pulmonary trunk and aorta, which in fetal life diverts blood away
from the unexpanded lungs, but normally closes after birth when the lungs are
viable.11 Due to the varying times it takes the ductus to close after birth, she
found that patients with Fallot’s tetralogy tended to become cyanosed
following the closure of the ductus. From this Taussig proposed the
manufacture of an artificial ductus by connecting or ‘anastomosing’ a systemic
artery, such as the aorta, to the pulmonary trunk.8 In theory non-oxygenated
blood in the aorta passes through the ductus into the pulmonary trunk and
back into the lungs to become oxygenated.6 Taussig initially attempted to
persuade Robert Gross to join her, however her endeavors were unsuccessful
and she recruited her new surgical colleague Alfred Blalock. On the 29th of
November 1944 Blalock performed the first systemic-pulmonary anastomosis
operation on a fifteen-month-old girl with Fallot’s tetralogy. William Longmire
was first assistant, Merel Harmel was anaethesiologist, and Vivian Thomas
and Helen Taussig were on hand to offer advice. The overall operation lasted
less than an hour and a half. The child left the hospital two months later alert,
active, tolerating feedings and having gained weight. However this recovery
was short lived with the patient sadly dying five days after a second shunt
operation six months later. During the surgery Blalock performed an end-toside anastomosis, joining the ‘end’ of left subclavian artery to the ‘side’ of the
left pulmonary artery. Originally the subclavian artery was selected, as without
the availability of the heart-lung machine, it was necessary to preserve blood
flow through one lung while the anastomosis was being implemented. Blalock
reflected on the technical difficulty of manipulating the tiny left subclavian
artery. So in his next two operations he opted to switch the left subclavian
artery for the brachiocephalic artery. The second operation, an end-to-side
anastomosis between the brachiocephalic artery and the left pulmonary artery
took place on the 3rd of February 1945. The second patient was an elevenyear-old girl with tetralogy of Fallot who before the operation was exhausted
after walking just thirty feet and panted when moving from a wheelchair to the
examining table. The results were outstanding, an uneventful post-operative
period facilitated an incredible recovery and three weeks later the patient
could walk sixty feet without panting. Seven days later, brimming with
confidence from the convincing results in the second case, Blalock altered his
procedure to perform an end-to-side anastomosis between the
brachiocephalic artery and the right pulmonary artery on a six-year-old boy
who was unable to walk. This operation released the potential of the
Blalock/Taussig operation and Taussig later wrote:
“The child later woke up in the operating room and asked, “Is the operation
over?” When Dr. Blalock said “Yes,” the child said “May I get up now?” from
that moment on he was a happy and active child.”12
Variations on the Blalock/Taussig operation have since emerged, notably the
following year in 1946 William Potts, Sidney Smith and Stanley Gibson
developed a direct side-to-side anastomosis between the descending aorta
and pulmonary artery. The key involving an ingenious clamp that allowed the
flow of blood through the aorta during surgery. Although the Potts/Smith shunt
was technically easier to perform than the classical Blalock/Taussig operation
it presented several postoperative complications including, excessive
pulmonary blood flow, distortion of the pulmonary artery, and problems during
subsequent complete tetralogy of Fallot repair. Accordingly the Potts/Smith
shunt was phased out.13, 14
Within two years, 500 patients underwent the Blalock/Taussig operation.
However its benefits as palliative surgery were limited and it was not a
definitive correction. Over a five-year follow-up of each patient multiple shunts
closed or shrank requiring a second operation. Neurological defects occurred
in a quarter of patients where the brachiocephalic artery was involved. 14 So
the hunt for a surgical cure was still on.
The Second Epoch – Closed-Heart Surgery
Although not the first closed-heart surgery, the second step in the treatment of
Fallot’s tetralogy followed in quick succession. Having made an incision into
the wall of the heart, the surgeon would ‘blindly’ dilate the constricted
pulmonary pathway with a knife or finger, while the heart remained beating.
This more elegant solution, called a ‘Pulmonary Valvotomy’, avoided two of
the potential problems of the Blalock/Taussing shunt, the failure of the shunt
to grow with the child and the harmful effects of an increased flow within the
pulmonary circulation. The aim was to restore the normal haemodynamics of
the heart, however as the ventricular septal defect remains open, the
symptoms of breathlessness will not completely be alleviated and the surgery
remained palliative. In 1926 Thomas Holmes Sellors qualified from the
Middlesex Hospital and University, in London. Here, working as a thoracic
surgeon, he developed and pioneered the surgical solution to pulmonary
stenosis. On the 4th of December 1947 he carried out the first pulmonary
valvotomy on a cyanotic, twenty-year-old patient with tetralogy of Fallot. On
palpation of the exposed heart he felt a firm structure, indicative of a
pulmonary valve that had not undergone perforation. Using a tenotomy knife
he made an incision through the right ventricle, and then skillfully sliced the
valve in two directions to open it.15 In 1947, Lord Russell Brock began his
search for the surgical correction of pulmonary stenosis at Guy’s Hospital,
also in London. As many patients with Fallot’s tetralogy did not have
pulmonary stenosis, he proposed a method of diagnosis using a cardioscope
in the early moments of the operation. He would insert the scope through an
incision made into the left pulmonary artery thus allowing direct vision to
examine the pulmonary valve. However after three unsuccessful trials, Brock
concluded that it was too dangerous to insert the cardioscope through the
pulmonary artery and temporarily stopped operating. Furthermore he had
taught himself to make the diagnosis through external palpation of the main
pulmonary artery, making the procedure redundant and hence abandoned.
After the invention of a new valvulotome and dilating forceps Brock was ready
to return. On the 16th of February 1948 he made a diagnosis of pulmonary
stenosis while operating on an eighteen-year-old girl suffering from Fallot’s
tetralogy. First he passed the new vavulotome through the wall of the right
ventricle, and passed it with ease through the valve and into the pulmonary
trunk. Next the forceps were inserted and dilated the stenotic valve. The
patient survived and her cyanosis was vastly improved. He performed two
more successful operations one three days later and a third in March. Within a
year the operation had matured and he added an additional instrument to his
repertoire, a special punch for the management of infunidbular stenosis. By
the end of 1952 he performed this operation successfully on over sixty
patients and he started to perform the pulmonary valvotomy in patients with
pulmonary stenosis as the sole malformation. Despite the difficulty of the
operations, the reward was great and Brock wrote: “we are in large part
recompensed for the long and difficult hours by seeing the almost miraculous
change in the children and in witnessing the joy and relief of the parents when
they see their children running about happily and without effort like other
children.”16
The Third Epoch – Open-Heart Surgery
Despite the revelations of these two techniques they were still only palliative.
The next logical progression in the treatment of Fallot’s tetralogy was to
combine dilating the narrowed pulmonary valve with repair of the hole caused
by the ventricular septal defect. In order to close the septal defect the heart
would have to be ‘opened up’ so that the internal structures could be
intricately inspected. As the brain is permanently damaged if deprived of
oxygenated blood for five minutes, unfortunately even the simplest open-heart
operation takes fifteen minutes. Two options eventually became available for
surgeons and their teams to conquer this (minimum) ten minute difference.
One option involved taking over the function of the heart – the ‘pump’, the
other by reducing the brain’s requirement for oxygen – induced hypothermia.
Previous work using general body hypothermia had been carried out
frequently before it application in the treatment of Fallot’s tetralogy. In the late
1940’s William Bigelow carried out ‘sham’ cardiac operations on dogs. In 1953
John Lewis and Mansur Taufic performed the first repaired of an atrial septal
defect when they reduced the patient’s body temperature to 28C. From that
point onward the induction of hypothermia became standard practice in
cardiac surgical technique. Multiple methods to induce hyperthermia were
available to the practicing surgeon, Lewis and Taufic used a refrigerated
blanket, Henry Swan of the University of Colorado, preferred immersion in an
ice-cold both, while Brock favoured an external circuit in which venous blood
was passed through a cooling coil. However the operating time provided by
this level of cooling was still too short for the correction of more complicated
and multiple abnormalities such as in Fallot’s tetralogy. In the late 1950’s
Charles Drew experimented with profound hypothermia reducing the body
temperature to 15C, which gave him the time he needed to carry out the
operation.17 A long-term solution was still needed, the function of heart and
lungs would need to be maintained by some other means than themselves,
long enough for the surgeon and their team to complete the operation. In
1931 John Gibbon formed the theory for extracorporeal circulation while
working nights. This was an audacious idea as in the 1950’s death was still
defined as the cessation of heart beat, so for a doctor to stop a patients heart
and then restart it seemed ludicrous to many. Gibbon’s ‘boss’ Edward
Churchill shared this negative viewpoint and in fact the only person who
appeared to share his vision was the Russian Professor S. S. Brukhonenko,
who had conducted some crude experiments on dogs. Most people believed
that a machine could not be capable to deliver suitable conditions for the vast
and complex functions of the heart, lung and circulatory system. Gibbon was
not deterred and by 1953 with the help of his wife Mary Hopkins he had
produced a machine capable of delivering consistently reliable results in
animals. Unfortunately for Gibbon only one of the four open-heart operations
he participated in survived, an eighteen-year-old woman, Celia with an atrial
septal defect. Disheartened by his failures Gibbon conceded he was out of his
depth, he felt he didn’t posses the surgical skill or psychological stamina to
continue and returned to the library.
With the successes of hypothermia in open-heart surgery and the failures of
the pump, the future of the cardiac surgery and the heart-lung machine looked
doomed. Nevertheless the work of Gibbon was picked up by two men in
Minnesota, Walter Lillehai at the University of Minneapolis and John Kirklin at
the Mayo Clinic in Rochester, and between them they would lay the
foundation for modern cardiac surgery. Lillehai was not a cardiac surgeon, but
he was a talented general surgeon, and as a surgical resident he had
participated in many common cardiac procedures. Lillehai’s success came
from developing a technique called cross-circulation, where the blood of the
patient was not passed through an oxygenator such as the heart-lung pump
but through a human volunteer. The genius of this technique was that the
artificial, man-made methods of oxygenation of the blood were replaced by
the most natural and physiological substitute. In August 1954 he initiated the
third step by completing the first total surgical correction of tetralogy of Fallot
in an 11 year-old boy. The pulmonary valve was dilated and the ventricular
septal defect was closed using a suture or patch depending on size. In a oneyear period that began in the spring of 1945, Lillehai completed forty-five
open-heart operations using cross-circulation in extremely ill patients, with
two-thirds of the patients surviving. It was clear, however, that crosscirculation was not the definitive answer as it exposed the healthy donor to
unacceptable risk. So focus was returned to advancing the pump developed
by Gibbon. Lillehai chose to work on a previous idea where oxygen was
bubbled outside the patient’s body in a reservoir circulated through patient
and returned debubbled. Kirklin believed the principles behind Gibbon’s pump
were sound and instead of designing a new machine he began to modify
Gibbon’s. In March 1955 Kirklin and his team were ready to begin, and they
used their machine in the treatment of intracardiac surgery in infants and
children and by May 1955 they performed eight operations with four survivors
and by October of the same year had performed thirty-eight operations with
sixteen survivors. Bearing in mind that most of the patients had end stage
congenital heart disease with ventricular septal defects and extensive
pulmonary hypertension and without intervention would have certainly died
the results were greatly encouraging. Kirklin had clearly demonstrated the
worth of the heart-lung machine in open-heart surgery.
Conclusion
As a medical student with an interest in both paediatrics and surgery the
surgical treatment of Fallot’s Tertalogy gave me a chance to cover both
topics. I was aware of some of the techniques used in modern day surgery but
this essay gave me the opportunity to understand the foundations from where
modern day techniques have evolved. The heart is anatomically the most
complex organ of the body and it is its intricacy and the previous taboo
towards cardiac surgery that has drawn me to it. Surgery is associated with a
steep learning curve, with a living drama in the literal life-or-death contest
being played out on the operating table. Without the psychological
determination of many surgeons the treatment of Fallot’s tetralogy would not
be where it is today. It is essential to appreciate the condition that surgeons
would have been presented with. Nowadays babies born with Fallot’s
tetralogy are operated on within the first year of life, so no surgeon will ever
see the “pitiful” sate of the patients Kirlin described. In my opinion, which is
one I share with Lord Brock, the Blalock/Taussig operation was “so
outstanding that it altered the whole approach to cardiology.”18 The genius
that lies in treating the congenital cardiac abnormality, Fallot’s tetralogy, by
creating a second congenital cardiac abnormality, a patent ductus arteriousus,
will rarely be succeeded. For me this study has stimulated a greater interest in
the varying techniques used in the management of congenital cardiac defects,
particularly those tetralogy of Fallot. Within the following year I hope to
witness firsthand this management by arranging multiple visits to the
Ninewells operating theatres to further my medical education.
REFERENCES:
1. James Le Fanu. 1999 Little Brown and Company. The Rise and Fall Of
Modern Medicine. Twelve Defining Moments, Chapter 6 – 1955: OpenHeart Surgery – The Last Frontier. Page 82
2. Ludwig Edeistein, Owsel Temkin, C Lilian Temkin. 1987 John Hopkins
University Press. Ancient Medicine. Page 6
3. Today I Found Out: How The Heart Works. C2010 [cited 2011 May 11].
Available from: http://www.todayifoundout.com/index.php/2010/09/howthe-heart-works/
4. Whonamedit? Fallots’ tetralogy. [cited 2011 May 11]. Available from:
http://www.whonamedit.com/synd.cfm/2281.html
5. P. Kumar and M. Clark (editors). 2009 Elsevier Limited. Kumar and
Clark – 7th Edition. Chapter 13 – Cardiovascular Disease – Congenital
Heart Disease. Page 779
6. James Le Fanu. 1999 Little Brown and Company. The Rise and Fall Of
Modern Medicine. Twelve Defining Moments, Chapter 6 – 1955: OpenHeart Surgery – The Last Frontier. Page 88
7. Louis J. Acierno. 1994 The Parthenon Publishing Group. The History
Of Cardiology. Section 2 Structural Abnormalities, Part B Congenital
Abnormalities, Chapter 13 – Congenital Abnormalities. Page 171
8. Peter Fleming. 1997 Amsterdam – Atlanta. A Short History Of
Cardiology. Chapter 13 – Cardiac Surgery. Page 219
9. Wikipedia: Fluoroscopy. [Modified 2011 May]. [cited 2011 May 12].
Available from: http://en.wikipedia.org/wiki/Fluoroscopy
10. Louis J. Acierno. 1994 The Parthenon Publishing Group. The History
Of Cardiology. Section 6 Therapeutic Modalities, Chapter 29 – Surgical
Modalities. Page 655
11. P. Kumar and M. Clark (editors). 2009 Elsevier Limited. Kumar and
Clark – 7th Edition. Chapter 13 – Cardiovascular Disease – Congenital
Heart Disease. Page 777
12. H. Taussig. Knowledge of Congenital Malformation of the Heart. Page
772*
13. V. N. Singh. Emedicine – Tetralogy Of Fallot: Surgical Perspective
Treatment & Management. [Updated 2008 November 13]. [Cited 2011
May 14]. Available from:
http://emedicine.medscape.com/article/904652-treatment#a1128
14. Louis J. Acierno. 1994 The Parthenon Publishing Group. The History
Of Cardiology. Section 6 Therapeutic Modalities, Chapter 29 – Surgical
Modalities. Page 656
15. T. Holmes Sellors. 1948 Surgery of Pulmonary Stenosis: A Case in
which the Pulmonary Valve was Successfully Divided. [Lancet, I:988]*
16. Brock. Surgery of Pulmonary Stenosis. Page 406*
17. Peter Fleming. 1997 Amsterdam – Atlanta. A Short History Of
Cardiology. Chapter 13 – Cardiac Surgery. Page 225
18. Letters from Lord Brock to Mark Ravitch. 1965 September. [Cited by
Raymond Hurt in The History of Cardiothoracic Surgery]
* Taken from – S. L. Johnson. 1970 The John Hopkins Press. The History of
Cardiac Surgery 1896-1955. Notes.
Bibliography:
James Le Fanu: The Rise & Fall Of Modern Medicine. Little, Brown and
Company, London, 1999.
Stephen L. Johnson: The History of Cardiac Surgery 1896-1955. The John
Hopkins Press, United States, 1970
Louis J. Acierno: The History of Cardiology. The Parthenon Publishing Group,
Carnforth, 1994.
Peter Fleming: A Short History Of Cardiology. Amsterdam – Atlanta,
Netherlands, 1997.
Knut Haeger, revised and updated by Sir Roy Calne: The Illustrated History of
Surgery. Harold Starke, Spain, 2000