WEDNESDAY MORNING, APRIL 28, 1971
8:30 A.M. Scientific Session:
THORACIC SURGERY FORUM Phoenix Ballroom
33. A New Technique for Rapid Saphenous Vein - Coronary Artery
Anastomoses
George J. Magovern, David C. Fecht,* Sang Bock Park,*
Gerald E. McGinnis,* and F. Beachley Main,
Pittsburgh, Pennsylvania
Coronary artery surgery utilizing aortico-coronary
artery saphenous vein bypasses introduces many technical problems - sutures
becoming entangled, the graft being difficult to handle, prolonged coronary
artery occlusion, etc. Stimulated by these adversities, we developed a
technique employing a new instrument which alleviates these problems.
Essentially, it is a saphenous vein holder which allows the vein to be brought
to the operative field mounted with the sutures pre-threaded through the graft
by an assistant. Distal coronary perfusion during anastomosis is also easily
achieved. The advantages of this instrument are outstanding. It accommodates
any size saphenous vein beveled at any angle. Suture identification numbers
eliminate the confusion attendant with multiple suture techniques. Of greatest
importance, the anastomotic time is decreased to one-fourth to one-third of
that required prior to the utilization of this instrument. We are presently
using it routinely. It is especially useful in those cases where the artery is
quite diseased; those hearts with borderline myocardial function; and those
cases where multiple veins are used. A movie strip will illustrate its use. We
feel this is a significant advance in coronary artery surgery and should be
brought to the attention of those engaged in this field.
34. Intramyocardial Gas Tensions in the Human
Heart During Saphenous Vein Coronary Artery Bypass
Timothy J.
Gardner,* John W. Brantigan, Avio M. Perna,*
Harvey W. Bender,* Robert K. Brawley,* and
Vincent L.
Gott, Baltimore, Maryland
Intramyocardial pO2 and pCO2 are
being continuously monitored in patients undergoing saphenous vein-coronary
artery bypass at The Johns Hopkins Hospital using a new Teflon membrane-mass
spectrometric technique developed here. Thus far, 25 patients have had this
operation requiring anoxic arrest for periods up to 40 minutes. Initial
myocardial gas tensions during cardiopulmonary bypaw averaged pp, 31 and pCO2
74. At peak anoxia, pO2, and pCO2 were 2 and 249. Several
minutes after the onset of saphenous vein flow, there is a period of reactive
hyperemia with the pO2 averaging 69 and the pCO2 57.
Following the period of reactive hyperemia with a more stable myocardial
perfusion, the pO2, averages 50. Following cardiopulmonary bypass
and with restoration of pulsatile flow, the pO2 valves average 78
and the pCO2 52. This is the first time that pCO2, and pO2
have been directly measured (nonpolarographic) in the human myocardium and the
results of this study suggest that the myocardial pO2 in patients
with coronary disease is considerably improved by saphenous vein bypass.
35. Left Heart Bypass without Anticoagulation
Richard M.
Enoelman,* Emery Nyilas,* and
Samuel J. Godwin,* New York, New York
Sponsored by Frank C. Spencer
A totally implantable, pulsatile bladder ventricle
containing air driven inflow and outflow valves and especially designed tubing
has been built entirely of Avcothane-51, a new nonthrcmbogenic blood compatible
polymer. The inflow end of the pump is placed in the apex of the left
ventricle. The pump lies in the abdomen with the outflow tube anastomosed
end-to-side to the abdominal aorta. Synchronous bypass at a flow rate of 750 to
1500 ml per minute (50-100% of the cardiac output) was used in five dogs for
periods of one to seven hours. Systemic, left ventricular, and right and left
atrial pressures were monitored during bypass. The systemic systolic pressure
was maintained between 80 and 160 mmHg (mean 50-130 mmHg) without vasopressor
support while left ventricular pressures were reduced by 50-100%. Urine output
remained between 5 and 20 ml per hour. Hematologic studies showed a decrease in
the fibrinogen level from 455 to 378 mg% and an increase in partial thromboplastin
time from 24.4 to 36.8 second?-after bypass. No significant changes were noted
in either the thrombin or prothrombin time. Platelet and white blood cell
counts were reduced by 25-50% and plasma hemoglobin rose from a control level
of less than 1 to 8 mg% during , bypass. At the completion of each bypass
period, the pump was carefully inspected for any evidence of clotting, and none
was found. The above data represents our initial experience with a
hemodynamically satisfactory pump. Continued experimentation is being
vigorously pursued.
36. Bi-Ventricular Bypass: Physiological Studies
During Induced Ventricular Failure and Fibrillation
W. F Bernhard, C. G. Lafarge,* M. Bankole,* and
W Bornhorst, Boston,
Massachusetti
Previous investigations in this laboratory demonstrated
that either right or left ventricular bypass was possible for periods of 85 and
170 days, respectively at flows of 4.0 to 8.0 liters/minute. Experiments were
performed using separate, implantable, pneumatically actuated, blood pumps each
with a stroke volume of 100 milliliters. This study was designed to assess the
effects of simultaneous biventricular bypass, (7-42 days), in calves during
induced myocardial failure and ventricular fibrillation. Physiological
observations were made by cardiac catheterization and biplane cineangiography
in 16 chronic animals: (1), control state (2), during electrically-induced
ventricular fibrillation (3-4 hours) and (3) during cardiac failure induced by
microsphere myocardial infarction. Under the: conditions, right and left
ventricular pressures were reduced to 0 mm Hg, cardiac output and systemic
arterial pressure were maintained at normal levels, end-diastolic volumes and
pressures were reduced, and ejection fraction improved. Mean pulmonary artery
pressure ranged between 10 and 30 mm Hg, and pulmonary compliance values were
comparable to control animals (left thoracotomy alone). Summary; The
physiologic abnormalities produced by chronic ventricular failure and brief
intervals of induced ventricular fibrillation can be reversed by an
implantable, circulatory support system.
37. Cardiac Function after Prolonged Storage in an Intermediate
Biological Host
Philip H. Wells,* Suriya Phalakornkvl,* Howard W.
Ramsey*
and Myron W. Wheat, Jr., Gainesville, Florida
The ready availability of healthy adequately
functioning hearts is a necessary requirement for large scale application of
cardiac transplantation. We have approached one aspect of this problem by
attempting to "store" the heart of one goat (donor) in the abdomen of a second
goat (host) and evaluating the function of the banked heart. This report
concerns a heart which was stored, remained in normal sinus rhythm for 47 days
and was evaluated in detail on the 35th and 43rd days of storage. Light and
electron microscopic sections demonstrate a gradual return to normal of the
cellular elements of the donor heart. At five weeks, the host heart recorded
left ventricular (LV) and left ventricular and diastolic (LVED) pressures of
142 mm. Hg and 3-5 mm. Hg respectively compared to donor LV 110-120 mm. Hg and
LVED 10-12 mm. Hg. Following isuprel, host heart dp/dt increased 6 percent,
donor heart dp/dt increased 27 per cent. Cineangiocardio-grams demonstrate
excellent contractility of the donor heart. Studies eight days later (43rd day)
indicated some further decrease of myocardial contractility and loss of
compliance in the donor heart. These studies suggest that a heart stored under
these conditions can maintain its ability to function adequately as a pump for
as long as six weeks.
38. Result of Total Artificial Heart Implantation in Calves
Clifford Kwan-Gett,* J. Kawai,* N.
Eastwood,* and
W. J. Kolff,* Salt Lake
City, Utah
Sponsored by Richard K. Hughes
We developed a new pneumatically powered total
artificial heart which pumps 10 liters per minute. It has two hemispherical
Silastic ventricles. Pumping diaphragms cannot touch the housing. Mechanical
crushing of blood cells is eliminated. Filling and therefore stroke volume and
cardiac output is proportional to atrial pressure. Atrial pressure
autoregulation is obtained without pressure transducers, feedback loops or
electronic control. In 14 calves weighing 68.0 to 90.7 kg, average survival
time after total mechanical heart replacement was 30 hours; 8 exceeded 24 hours
(average 49, maximum 92 hours). Postoperatively, animals could eat, drink, move
and stand unsupported. Pulmonary artery pressures in long survivals were normal
despite abnormal pressure waveforms. Hemolysis production was low. Plasma
hemoglobin always fell from post pump-oxygenator levels. Twice it fell to 2 mg%
from 36 mg% and 34 mg% in 63 and 36 hours. With serial determinations in 3
experiments, fibrinogen levels were low after bubble oxygenator support, rose
towards normal, then fell rapidly prior to termination. Platelet levels at
termination were extremely low (1,500 to 75,000 per cmm). Plasma protein levels
fell gradually. The fall in fibrinogen, platelet, and hematocrit levels with
increase in Lee-White clotting time at termination, suggests that consumptive
coagulopathy limits survival times.
39. Transvenous Pulmonary Embolectomy by a Catheter Device
L.J. Greenfield, M. E. Reif,* E. R. Munnell, and
T.A. Bruce,* Oklahoma
City, Oklahoma
The high mortality rate associated with open pulmonary
embolectomy has prompted a search for other approaches to the problem, and a
new catheter technic has been used successfully in both experimental and
clinical studies. The vacuum-cup catheter device is attached to a 12 Fr.
double-lumen balloon-tipped catheter which can be introduced through a large
extremity vein. In a total of 38 large mongrel dogs, acute massive pulmonary
embolism has been produced using autologous thrombi, muscle strips, and human
thrombotic material. Extraction of embolic material was possible with the
catheter device under fluoroscopy in 83% of the animals and was associated with
reduction in pulmonary vascular resistance and improved cardiac output.
Arterial blood gases did not improve for 24-48 hours. The technic has been
applied to two patients with pulmonary embolism in whom emboli were removed
successfully under local anesthesia. Both patients showed immediate hemodynamic
improvement, improved perfusion by angiography and lung scan, and are
asymptomatic at three months follow-up. Rapid extraction of pulmonary emboli is
possible without total cardiopulmonary bypass or general anesthesia and this
technique should broaden the indications for pulmonary embolectomy.
40. A Low Pressure Tracheostomy Tube Cuff to
Minimize Tracheal Injury: A Comparative Clinical Trial
Joel D. Cooper,* Hermes C. Grillo, Bennie Geffin,*
and Hennng Pontoppidan,* Boston,
Massachusetts
Conventional tracheostomy tube cuffs may cause pressure
necrosis which results in tracheal stenosis, trachec-malacia, tracheo-esophageal
fistula or innominate artery erosion, since such cuffs require high inflation
pressures, are relatively rigid and deform the trachea when a seal is obtained
for ventilatory support. To obviate such necrosis a new compliant cuff was
designed which provides a seal by conforming to the shape of the trachea
and has low intracuff pressures. Randomized trial of the new cuff in comparison
with standard cuffs was made in 46 unselected patients who required
tracheostomy for ventilatory assistance. Damage to trachea was evaluated by
telescopic examination after removal of the cuff or by postmortem examination.
Tracheal injury was classified into four groups, ranging from absent or minimal
damage to severe ulceration with cartilaginous slough. Half of the patients
with new cuffs showed absent or minimal damage. No patients with standard cuffs
were in this group. Most patients in severe damage categories had standard
cuffs; few patients with new cuffs demonstrated severe damage. Results were
highly significant statistically. Intracuff pressures in experimental cuffs
averaged only 25 mm. Hg in comparison with 250 mm. in the standard. These
clinical observations in man are consistent with prior experimental data in
dogs.
41. Prepulmonary
Oxygenation by Peripheral Cannulation for Respiratory Distress
A. B. Iben* D. F. Pupello,* T. N. Grehl,* and
E. J. Hurley, Davis,
California
Venoarterial pump oxygenator support for patients with
respiratory insufficiency is an inefficient method. It decreases preload,
increases systemic resistance, and unfavorably alters forward cardiac output
and tissue perfusion. Most present methods use roller pumps and peripheral
application resulting in nonpulsatile flow. By the use of two triple lumen
catheters introduced from the jugular vein above and the femoral vein below, up
to 95% of the systemic venous blood can be removed, oxygenated and returned to
the right atrium. Side openings in the large lumened catheter removes blood
from the patient to the oxygenator. Another lumen within the catheter returns
blood to the right atrium. The third lumen connects to an inflatable balloon,
which when inflated in the caval atrial junction, separates the two systems.
The heart continues to function as a pulsatile pump. The entire system
including the lungs receives oxygenated blood. Methods of catheter application
are described as well as serial arterial blood gas determinations carried out
in 24 canine laboratory subjects. The pathological findings of serial pulmonary
biopsies removed during the period of perfusion are presented. With the advent
of membrane oxygenators, which can be used for extended periods of time, this
method of cannulation and prepulmonary oxygenation shows great promise as a
useful clinical tool for the treatment of acute respiratory insufficiency in
any age group.
42. A New System for Computerized Automated Blood Gas Analysis
L. George Veasy,* Justin S. Clark,* A. Larry
Jung,*
Jarrell L.
Jenkins,* and Conrad B. Jenson,*
Salt Lake City, Utah
Sponsored by Russell M. Nelson
An automated system for on line, real time computerized
determination of arterial PO2, PCO2, and pH has been
developed (CABAS). The determinations are made from a total of 0.3 ml sample of
blood withdrawn automatically under computer control from an indwelling arterial
catheter, which is not limited to CABAS function. The results are displayed
within four minutes in alpha-numeric terms on a memory scope at the cribside.
System sterility tests in 10 consecutive experiments having a total of 40
cultures had no positive growth. Accuracy of CABAS determinations compared with
the ASTRUP technique showed a mean difference of 1.3 mm Hg with a standard
deviation of 4.6 mm Hg in 60 measurements of PO2 0.4 mm Hg with a
standard deviation of 1.5 mm Hg in 18 measurements of PCO2, and
0.018 pH units with a standard deviation of 0.031 in 69 measurements of pH. The
shorter time required for results, minimal amount of blood required for
analysis, no disturbance of infant for sampling, and automated and scheduled
sampling have helped in the management of many problems before they were
clinically apparent in 9 cases of respiratory distress syndrome.
43. Surgical Techniques for Replacement of the Interven-tricular Septum
Shuji Seki,* and Dwight C. McGoon, Rochester, Minnesota
An operative technique has been developed for replacing
the interventricular septum, which may prove useful in correction of single
ventricle and provide a way to study the function of the septum. The septum is
resected at the free wall and atrioventricular valves and is replaced with a
Teflon felt patch. The tricuspid valve is replaced with a prosthesis, and
rhythm is maintained by an implanted pacemaker. Operative techniques were
investigated in 15 dogs and effects of size and positioning of the patch were studied
in 45 others. Anchoring stitches to the free wall must be tied outside the
ventricle. A ball valve was not suitable because the patch bulged toward the
right. Size of the defect and positioning of the patch were not important
because the primary function of the patch was to divide the single ventricle
into two cavities, volumes of which were in the normal range. If the patch size
was equal to the defect size in diastole, the patch was too large and bulged
toward the right ventricle. The patch must be smaller than the diastolic
defect; 5 of 9 dogs with patches 22% smaller survived longer than 1 month.
44. Surgical Correction of Complete
Atrio-ventricular Canal Utilizing Ball Valve Replacement of Mitral Valve:
Technical Considerations
Aldo Castaneda, Demetre Nicoloff,* James
Moller,*
and Russell Lucas,* Minneapolis,
Minnesota
Operative correction of complete atrio-ventricular
canal (CAVC) has been associated with both a high mortality and a high
incidence of residual abnormalities, particularly mitral regurgitation. To
improve the operative results, we now resect the malformed and malpositioned
mitral valve. An hour-glass shaped Teflon patch is fashioned and one portion of
this sewn in the ventricular component of the defect. A ball valve prosthesis
is sutured into the mitral annulus until its medial aspect is reached. The
valve is fixed to the patch about two centimeters above its ventricular septal
attachment and at the level corresponding to the true A-V plane. The atrial
segment of the patch is used to close the remaining primum defect. Finally the
septal leaflet of the tricuspid valve is relocated in the appropriate A-V plane
on the right side of the patch. Four children with CAVC, from 2V4 to 5 years of
age, have been operated upon by this technique. Two had previous operations but
required re-operation because of significant residual ventricular shunts and
mitral insufficiency. In each of the four patients, massive mitral
insufficiency was present preoperatively. The average mean pulmonary arterial pressure
was 80 mm Hg and pulmonary vascular resistance was 1250 DSC5. One
child (who developed complete heart block following the first operation) died
24 hours after the second. Each of the remaining patients is well and has no
residual murmur. A-V block has not occurred.
*By
Invitation
