Reprinted from the Archives of Surgery
October 1950, Vol. 61, pp. 732-737

Copyright, 1950, by American Medical Association

ARTERIAL HOMOGRAFTS

Il. Resection of Thoracic Aortic Aneurysm Using a Stored Human Arterial Transplant

HENRY SWAN, M.D.
CLARENCE MAASKE, Ph.D.

MARVIN JOHNSON, M.D.
AND

ROBERT GROVER, B.A.
DENVER

sent PROBLEM of bridging a large gap in a major artery has

long been one of importance to both the civilian and the military
surgeon. Peirce and his co-workers ' have recently reintroduced interest
in the use of stored arterial homografts for this purpose. In their pre-
liminary studies on dogs these workers demonstrated that such homo-
grafts, if taken aseptically within the first few hours after death ot
the donor animal, could be stored in a standard refrigerator when placed
in buffered salt solution containing 10 per cent dog serum. When
transplanted into a recipient animal after storage up to fifty days, these
homografts would function successfully as a conduit of blood for. periods
longer than a year. A high percentage of successful “takes” could be
obtained by careful anastomotic technics. In addition, it was shown by
tissue culture methods that “viable” cells persisted in the stored vesseis
up to forty days. Gross? has subsequently used the stored human
arterial homograft in the repair of coarctation of the aorta.

Read at the Seventh Annual Meeting of the Central Surgical Association,
Chicago, Feb. 17, 1950.

This study was supported in part by United States Public Health Service grant
H-241 and in part by the Life Insurance Medical Research Fund.

From the departments of surgery and physiology, and the Cardiovascular-
Pulmonary Research Laboratory, University of Colorado School of Medicine.

1. Peirce, E.C., IL; Gross, R. E.; Bill, A. H., Jr., and Merrill, K.. Jr.:
Tissue-Culture Evaluation of the Viability of Blood Vessels Stored by Refrigera-
tion, Ann. Surg. 129:333 (March) 1949. Gross, R. E.; Bill, A. H., Jr., and
Peirce, E. C., Il: Methods for Preservation and Transplantation of Arterial
Grafts: Observations on Arterial Grafts in Dogs; Report of Transplantation of
Preserved Arterial Grafts in 9 Human Cases, Surg., Gynec. & Obst. 88:689 (June)
1949.

2. Gross, R. E.: Blood Vessel Grafts, read before a meeting of the Surgery
Study Section, National Institutes of Health, United States Public Health Service
(Jan. 21) 1950.

 
 

2

In a previous communication,’ we reported experimental data sug-
gesting that the storage solution can be extremely simple, consisting
solely of Ringer’s solution to which has been added 10 per cent by volume
of homogenous plasma. Vessels stored in this solution in a common
refrigerator for as long as six months have been transplanted into
recipient animals with consistent success and have remained functional
for periods exceeding one year. Careful pathologic study indicated
that in the case of short storage grafts, i. e., grafts stored less than
forty days, there was often some survival of smooth muscle. In both
short storage and long storage grafts the elastic tissue of the media
survived relatively intact for many months. All other tissue layers
disappeared and were replaced by layers which grew in from the host.
It was our feeling that the longer the storage the earlier and more
prominent was the appearance of mild degenerative changes in the new
vessel. These changes consist of fibrillary destruction of elastic tissue
and diffuse calcification of the media and the new intima. In general,
therefore, it would appear that grafts stored for less than forty days are
preferable, although the evidence on this point is not entirely clearcut,
and vessels stored for much longer periods give satisfactory short term
results.

Before the use of the homogenous arterial graft may become wide-
spread, it will be necessary to solve the many practical problems related
to the establishment of an artery bank. Obtaining suitable vessels is
often difficult. The donor should be young and should have been in
previous good health before succumbing to a rapid, noninfectious fatal
episode. The graft must be taken aseptically within six hours of death.
This combination of requirements is exceedingly difficult to fulfil, even
in a large city. With current storage methods, the vessel is probably
best used within a period of forty days, thus requiring a rather rapid
turnover of vessels. Ways and means must be sought to develop an
effective method of preservation for long periods. Rapid freezing
technics and fixation with formaldehyde or alcohol are currently being
investigated in several laboratories in this country.

The limitations on the use of homogenous arterial grafts have not
yet been clearly delineated, particularly in regard to the size and length
of the transplant. What is the smallest artery into which a graft may
be successfully transplanted? Miller and his co-workers * have reported
good function in the femoral artery of dogs. One of us (H. S.) has had
gratifying results with the femoral artery in human patients. It would

3. Swan, H.; Robertson, H. T., and Johnson, M. E.: Arterial Homografts:
The Fate of Preserved Aortic Grafts in the Dog, Surg., Gynec. & Obst. 90:568
(May) 1950.

4. Miller, H. H.; Callow, A. D., and Welch, C. S.: The Fate of the Arterial
Graft in Small Arteries, Bull. Am. Coll. Surgeons 35:55 (Jan.) 1950.
3

seem probable that even smaller vessels, such as internal carotid,
popliteal, or superior mesenteric arteries, could be successfully bridged.
What is the maximum length of graft which can safely be used? This
question has not been thoroughly studied experimentally. Gross * has
used human aortic grafts from 2 to 6 cm. in length. In one of our
patients with a femoral transplant, the segment was 7 cm. long. In
the case reported in this communication, the aortic segment was 8 cm.
long. Perhaps even longer segments might be successful. On the other
hand, it is possible that there is a relation between the size of the vessel
and the greatest usable length of graft.

CASE REPORT

W. M., a 16 year old school boy, was first admitted to the surgical service of
the Colorado General Hospital on May 15, 1949, with a complaint of exertional
dyspnea and easy fatigability of five years’ duration. At the age of 11, on a routine
physical examination, it was discovered that he had congenital heart disease,
probably coarctation of the aorta. Three weeks later he became seriously ill and
was hospitalized and treated for subacute bacterial endocarditis with sulfonamide
drugs and with malarial fever therapy. After a two month stay, he was sufficiently
improved to continue treatment on an outpatient basis, but a relapse occurred
several months later, requiring rehospitalization. At this time he was treated with
penicillin, which was continued for a period of several months. Since that time
the patient had noticed dyspnea with mild exertion and occasional palpitation.
In addition, dizzy spells with occasional fainting had occurred about twice a
month for the past year. There had never been cyanosis or peripheral edema.
Physical examination revealed a well developed but thin, intense white boy in no
distress. The pulse rate was 130 and the blood pressure 175 systolic and 105 dia-
stolic in both arms. No blood pressure or arterial pulsations could be obtained
in the legs. The heart was not enlarged to percussion. A grade II blowing
systolic murmur could be heard in the second interspace on each side of the
sternum. In addition, there was a lower-pitched grade I systolic murmur over the
apex. The aortic second sound was greater than the pulmonic second sound,
although both were snapping in character. No cyanosis or edema of the extremities
was evident. The day after admission, simultaneous direct arterial pressure
recordings were made in the brachial and femoral arteries on the left. The
brachial pressure was 175 systolic and 100 diastolic and the femoral pressure 93
systolic and 82 diastolic. Attempted intravenous angiocardiographic examination
was unsatisfactory. The patient was discharged, to be readmitted during the
school vacation for repair of his coarctation. Operation was performed on June
28, 1949. An adult type of coarctation, 2 cm. below the origin of the left sub-
clavian artery, was found. Below the coarctation was an aneurysm of the aorta
about 2 inches (5 cm.) in length and 2 inches in diameter, irregular in shape with
areas of calcification within its walls. After mobilization of the various structures
it did not appear to be safe to attempt resection of the coarcted area only with
anastomosis between the aneurysm and the descending aorta above. Accordingly,
a decision was made to resect the coarctation and the aneurysm a distance of about
2¥2 inches (6 cm.) and to bridge the gap with an arterial homograft. We had
available an aorta which had been obtained aseptically three hours after the death

5. Gross, R. E.: Personal communication to the authors.
4

of a 14 year old boy who had been killed in an automobile accident fifty-two days
previously. -This had been stored in Ringer’s plasma in the blood bank refrigera-
tor. The length of the segment selected was 8 cm. The coarctation and aneurysm
were now resected, and the gap was bridged by means of the graft. The proximal
anastomosis was difficult because of the friable nature of the aorta at this point
and had to be repeated. During the procedure there was one moment of brisk
hemorrhage, but this was soon controlled, and the child left the operating table
after the nine and one-half hour procedure in apparently good condition. The
postoperative course was essentially uneventful with the exception of the behavior
of the blood pressure. On the first postoperative day the pressure rose to the
neighborhood of 200 systolic and 130 diastolic, where it remained with some fluctua-
tions for a period of eight days. During this period, there were full bounding
pulses palpable throughout both lower extremities. The urinary output was normal.
Because of our concern with the possible fate of the graft in the face of this hyper-

 

Fig. 1—A, photograph of resected aortic aneurysm as seen from below. Bs,
specimen as seen from above. The area of coarctation is just superior to the
irregular aneurysm.

tension, the patient was given repeated large doses of tetraethyl ammonium chloride
(etamon chloride®), but without noticeable effect on the blood pressure. During
‘tthe next two weeks the blood pressure showed a slow trend toward normal levels,
‘until at the time of discharge, four weeks after operation, the blood pressure in
iboth arms and in the left leg was 135 systolic and 90 diastolic. In the six months
that have elapsed since this operation, the patient has been feeling well, no longer
observes exertional dyspnea and has had no further attacks of vertigo or fainting.
Good femoral pulsations are still palpable, but the blood pressure in the arms has
risen to about 160 systolic and 90 diastolic.

COMMENT

This human arterial homograft which had been in storage for fifty-
two days at the time of transplantation has apparently remained
5

functional for a period of six months. At the present time the heart is
normal in size on roentgen ray examination and there is no evidence of
calcification appearing in the area of the transplanted vessel. The long
term result, of course, cannot be predicted with accuracy.

| be
\ (ween 16 MAY 1949 /

fl ela
6 WEEKS PRE-op

NI Psat fae N

BRACHIAL ART ITO,

|
ae a ee el Oe ee

FEMORAL ART 920
if
ae

| bee

el a

WM 23 JULY 1949
1 ’ 1
3 WEEKS POsT- OP
i

DNINUNININUINN

|
BRACHIAL ART. "35.09

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

L 1 1 ' 1 |
FEMORAL ART. 135.5

 

 

 

 

 

B

 

 

 

 

 

 

 

 

 

Fig. 2—In (A) simultaneous strain gage intra-arterial pressure tracings of the
left brachial and femoral arteries taken six weeks before operation are shown. The
low femoral pulse and abnormal contour can be contrasted with the femoral artery
tracing (B) taken three weeks after operation.

Of particular interest is the behavior of the patient’s blood pressure
since operation. The whole problem of the etiology of the hypertension
6

associated with coarctation is currently an unsettled one. Rytand ® and
Steele’ have suggested that the diastolic hypertension in the lower
extremities of many of these patients could not be explained on a
mechanical basis and postulated interference with renal blood flow.
Studies of renal blood flow, however, by Bing and others® and by
Barker and Clark® did not substantiate any relation between hyper-
tension in patients with coarctation and a renal mechanism. After repair
of a coarctation alone, we’ have observed an instability in several
patients, with considerable fluctuation in blood pressure during the
immediate postoperative period and a gradual tendency to stabilize within
normal ranges. Strain gage intra-arterial pressure recordings taken
preoperatively and postoperatively have shown that the femoral pulse
contour and the radial-femoral ratio have reverted almost to normal by
six weeks after operation. In this patient, however, after this return to
normal, there has been a gradual increase to mildly hypertensive levels
in the upper extremities so that during the past two months his blood
pressure has been running in the neighborhood of 160 systolic and 190
diastolic, despite the fact that he now demonstrates markedly improved
femoral pulse contour. It would appear to be difficult to explain these
changes in blood pressure on a purely mechanical obstructive basis, and
interference with the pressure-regulating mechanisms of the aortic arch,
generalized increase in vascular tone or some renal mechanism must
apparently be postulated. At the present time we have no explanation
for this puzzling phenomenon.

SUMMARY

An adult type of coarctation of the aorta together with a mycotic
aneurysm of the descending aorta in a 16 year old boy was resected and
the gap in the aorta bridged by an 8 cm. human arterial homograft,
which had been stored for fifty-two days. Six months after operation
the vessel is apparently functioning well.

6. Rytand, D. A.: The Renal Factor in Arterial Hypertension with Coarcta-
tion of the Aorta, J. Clin. Investigation 17:391 (Jan.) 1938.

7. Steele, J. M.: Evidence for General Distribution of Peripheral Resistance
in Coarctation of the Aorta, J. Clin. Investigation 20:473 (Sept.) 1941.

8. Bing, R. J.; Handelsman, J. C.; Campbell, J. A.; Griswold, H. E., and
Blalock, A.: The Surgical Treatment and the Physiopathology of Coarctation of
the Aorta, Ann. Surg. 128:803 (Oct.) 1948.

9. Barker, H. G., and Clark, J. K.: Renal Function in Coarctation of the
Aorta, Bull. Am. Coll. Surgeons 35:53 (Jan.) 1950.

10. Grover, R. F.; Swan, H., and Maaske, C. A.: Intra-Arterial Pressures
Before and After Aortic Resection for Coarctation in Man, Federation Proc.
9:53 (March) 1950.

Printed and Published in the United States of America