Thorax: first published as 10.1136/thx.19.2.131 on 1 March 1964. Downloaded from Thorax (1964), 19, 131
Homograft aortic valve replacement in aortic incompetence and stenosis
B. G. BARRATT-BOYES From the Cardio-thoracic Surgical Unit, Green Lane Hospital, Auckland, New Zealand
The surgery of aortic incompetence and calcific suggests that homograft aortic valves are worthy aortic stenosis has made disappointing progress, of serious consideration for aortic valve replace- chiefly because of the need for partial or total ment. valve replacement in many of these patients and MATERIAL the technical problems inherent in designing an artificial valve. In rheumatic aortic incompetence During the 16 months from August 1962 to Novem- it is now fairly clear that total replacement of the ber 1963 inclusive, the aortic valve has been com- valve is almost always required (McGoon, Man- pletely excised and replaced by a homograft aortic valve in 21 patients with aortic incompetence, 17 with kin, and Kirklin, 1963), and in calcific aortic calcific aortic stenosis, and six with multivalvular stenosis the lesion is by no means always ade- disease. Clinical data obtained before and after opera- quately relieved by decalcifying the cusps, so that tion in these 44 patients and various operative findings partial or total valve replacement is necessary in are listed in the Table. In this same period one further a proportion of these cases also. patient with aortic incompetence underwent operation, Dissatisfaction with the available plastic aortic and it was intended to replace the valve with a homo- copyright. valve prostheses led to a review of the experi- graft valve. Death occurred, however, immediately mental and clinical experience with homograft bypass was started from retroperitoneal rupture of an aortic valves. The experimental evidence (Murray, aortic dissection which began at the site of cannula- 1956; Lam, Aram, and Munnell, 1952; Brewin, tion of the external iliac artery and ended at the point of rupture. The aortic wall showed extensive medio- http://thorax.bmj.com/ 1956; Beall, Morris, Cooley, and De Bakey, 1961), necrosis at necropsy. Although this was a 'perfusion ' while a little conflicting, suggests that with the death, it does not reflect directly on homograft valve host valve rendered incompetent a homograft replacement and will not be considered further. valve will function in the dog. Clinical experience The ages varied from 14 to 66 years, and 20 patients from Toronto (Murray, 1956; Kerwin, Lenkei, were over the age of 50. Symptoms have been divided and Wilson, 1962), where homograft aortic valves into four grades of severity: grade 4 if there was a have been inserted in the descending thoracic aorta history of congestive heart failure, paroxysmal noc- in patients with severe aortic incompetence, shows turnal dyspnoea, orthopnoea or angina decubitus; grade 3 if there was angina of effort or syncope in
will function for on September 27, 2021 by guest. Protected that these valves normally up addition to effort dyspnoea; and grade 2 if there was to six years. The evidence seemed sufficient to moderate effort dyspnoea only. On this basis 28 of justify attempts to insert homograft valves in a the 44 patients had grade 4 symptoms, 11 grade 3, and subcoronary position in anticipation that they five grade 2. The electrocardiogram showed a complete would function better and for longer periods than left bundle branch block in cases 22 and 31 and a plastic prostheses. complete right bundle branch block in case 21. Left The technique used for inserting the valve was ventricular surface leads and their equivalents showed based on experience gained in approximately 100 inverted T waves with or without ST depression, indi- open operations on the aortic valve and was first cating severe left ventricular hypertrophy in all but before the three of the remaining patients, and in these (cases 16. used in August 1962 receiving report 19. and 35) the changes were moderate with T waves of a similar procedure performed by Ross (1962) of low voltage. at about the same time. The technique has proved very satisfactory and the valves have all con- PREVIOUS SURGERY Four patients had had previous tinued to function well. Indeed the experience pre- heart-lung bypass surgery, three for calcific aortic sented here, including necropsy examination of stenosis (cases 12, 17, and 22) and one (case 15) for two valves three and a half and four and a half ventricular septal defect with severe aortic incom- months after insertion, is most encouraging and petence. In case 12 the surgery was undertaken else- 131 Thorax: first published as 10.1136/thx.19.2.131 on 1 March 1964. Downloaded from
132 B. G. Barratt-Boyes
TABLE Gradient Perfusion Data Across Grade Homo- Follc)w-up (December 1963) of Coronary Haemo- graft Case Age,'Sex/ Symp- B.P. By-pass Perfusion lysis Valve 'Post-operative B.P. No. Operation toms (mm.Hg) (min.) (min.) (mg. %) (mm.Hg) Complications (mm.Hg) Murmur' Status ..i1.I 1 Aortic Incompetence 14 F 4 140, 35 0 101 88 73 0 Nil 105 !70 M.S.M. 0-1 Good 23.8.62 E.D.M. 0-1 2 21 M 4 135,30-0 114 93 52 0 Nil 115,90 M.S.M. 1-2 Poor 9.10.62 (Cardio- myopathy) 3 54 M 4 180J'40 108 83 144 0 Nil 165!80 M.S.M. I Good 6.11.62 4 36 M 3 170 40-0 143 101 146 Nil 150 90 M.S.M. 1-2 Good 18. 12.62 E.D.M. 1-2 5 32 F 3 160,,20-0 112 88 88 8 Bleeding, Died 15.1.63 6 27 M 2 170i60 117 82 40 3 Positive blood 135185 M.S.M. 1-2 Good 29.1.63 culture E.D.M. 1-2 7 62 F 4 140,150 100 78 39 4 Nil 145 85 M.S.M. 1-2 Died 28.2.63 E.D.M. 1-2 (June 1963) 8 45 M 3 18040-0 105 84 56 0 Nil 140 85 M.S.M. 0-1 Died 14.3.63 (July 1963) 9 55 M 4 2001t60 116 81 29 Nil 140,'85 M.S.M. 1-2 Good 18.4.63 E.D.M. 0-1 10 52 M 4 165/35 179 153 59 10 Nil 130170 M.S.M. 1-2 Good 2.5.63 11 23 M 2 165,35-0 104 82 28 0 Nil 160190 M.S.M. 1 Good 8.5.63 P.S.M. 1-2 12 60 F 4 170'40 95 77 46 3 Nil 130/70 M.S.M. 1-2 Good 12.6.63 13 17 F 4 150 0 105 85 47 0 Nil 130 80 M.S.M. 1-2 Good 27.6.63 E.D.M. 1-2 14 27 M 4 130/30 127 96 24 14 Post-perfusicn 1 10'80 M.S.M. 2 Good 3.7.63 syndrome E.D.M. 1-2 15 16 M 4 145'0 101 U/67 30 Nil 140 75 M.S.M. 2 Good 3 1.7.63 E.D.M. 2 copyright. 16 23 M 2 140'55 150 121 57 Nil 135, 80 M.S.M. 1-2 Good 17.10.63 E.D.M. I 17 60 M 4 170/60 96 78 30 Nil 150 80 M.S.M. I Good 29.10.63 E.D.M. 1-2 18 63 M 4 130/40 128 103 15 Nil 130,85 M.S.M. 1-2 Good 6.11.63 E.D.M. 0-1 19 18 M 2 140i0 91 71 47 Nil 130,85 M.S.M. I Good
7.11.63 http://thorax.bmj.com/ 20 41 M 4 205,50-0 132 102 150 Arrhythmia 160/100 M.S.M. 1-2 Good 12.11.63 cardiac arrest E.D.M. 1-2 21 48 M 4 220,150-0 117 90 36 Nil 140i90 M.S.M. 1-2 Good 21.11.63 Calcific Aortic Stenosis 22 47 M 4 1 10!80 132 103 304 4 Nil 125/80 M.S.M. 1-2 Good 13.12.62 E.D.M. I 23 53 M 3 1 10/80 133 113 30 36 Pulmonary embolus 135/80 M.S.M. 1-2 Good 27.2.63 24 59 M 4 110'85 143 106 40 Nil 110170 M.S.M. 1 Good 11.6.63 25 54 M 3 105 70 121 94 15 8 Pulmonary embolus 110/70 M.S.M. 1 Good 9.7.63 26 45 M 4 110l50 125 95 33 Nil 1301!85 M.S.M. 1-2 Good on September 27, 2021 by guest. Protected 10.7.63 E.D.M. 1-2 27 51 M 3 120'75 128 104 43 6 Dissection left 18.7.63 coronary Died 28 54 M 3 120175 121 99 27 0 Pulmonary embolus 130,'80 M.S.M. 0-1 Good 23.7.63 29 50 F 3 120180 130 95 56 0 Heart block 130'80 M.S.M. 1-2 Good 6.8.63 (temporary) 30 52 M 4 110150 109 72 22 0 Nil 115/70 M.S.M. 1-2 Good 8.8.63 31 56 M 3 135/80 134 107 69 0 Post-perfusion 130/70 M.S.M. 1-2 Good 15.8.63 syndrome E.D.M. 1-2 32 50 F 3 125,'85 111 78 27 0 Nil 140/80 M.S.M. 1-2 Good 22.8.63 33 57 M 4 115,175 117 81 19 0 Post-cardiotomy 130/85 M.S.M. 1-2 Good 4.9.63 syndromne E.D.M. 0-1 34 52 M 2 140'90 111 83 41 Nil 135/85 M.S.M. 1 Good 16.10.63 35 36 M 3 110/85 148 123 56 0 Nil 125/70 M.S.M. 1 Good 30.10.63 E.D.M. 1 36 66 M 4 160/115 128 83 45 Heart block 130,'80 M.S.M. 1 Good 31.10.63 (temporary) 37 59 M 4 120165 137 80 20 Nil 130,175 M.S.M. 1 Good 13.11.63 38 59 M 4 140170 105 81 65 Nil 115'70 M.S.M. I Good 14.11.63 (continued) Thorax: first published as 10.1136/thx.19.2.131 on 1 March 1964. Downloaded from
Homograft aortic valve replacement in aortic incompetence and stenosis 133
TABLE-(continued)
Gradient Perfusion Data Across Grade Homo- Follow-up (December 1963) of Coronary Haemo- graft Case Age/Sex! Symp- B.P. By-pass Perfusion lysis Valve Post-operative B.P. No. Operation toms (mm.Hg) (min.) (min.) (mg.%) (mm.Hg) Complications (mm.Hg) Murmur1 Status Multivalvular Disease 39 54 M 4 155'65 137 110 33 _- Heart block 115/80 M.S.M. 1 Fair A.I.andl 25.6.63 (permanent) P.S.M. 2 M.I.I40 43 F 4 155/80 164 140 40 - Nil 110/70 M.S.M. 2 Good A.I. 25.7.63 AS. and M.S. 41 36 F 4 120/50 117 83 29 0 Nil 115,80 M.S.M. I Good A.l. 12.9.63 E.D.M. 1 A.S. and M.S. 42 22 M 4 150240-0 145 102 55 _ Heart block 135l85 M.S.M. 1 Good AlI. 24.9.63 (temporary) E.D.M. 2 and P.S.M. 1-2 43 35 M 4 190,80 173 150 54 - Ploay108 ...12 Go A.]. 3.10.63 complications E.D.M.i and M.I. 44 20 M 4 120,50 195 155 56 - Heart failure AlI. 15.10.63 Died M.S. and T.I. 1Murmurs graded 1 to 4. M.S.M. -mid-systolic (aortic) E.D.M. early diastolic (aortic) ;P.S.M. pan stystolic (mitral). A.I. = aortic incompetence; M.I. = mitral incompetence TI. - tricuspid incompetence; A.S. = aortic stenosis; M.S. = mitral stenosis. copyright. where in October 1958, when one cusp of a bicuspid time available the cusps were not fully mobilized. valve was replaced with an artificial leaflet and the Symptoms recurred within eight months and pro- other leaflet partially decalcified. This operation was gressed to effort dizziness and paroxysmal nocturnal followed by renal shutdown which required dialysis dyspnoea, and physical signs indicated a return of http://thorax.bmj.com/ twice before function returned, but the patient was severe aortic stenosis. moderately improved for a year or so, when angina In case 15 the initial operation was in May 1963, returned: later congestive heart failure appeared. at which time the ventricular septal defect was closed Aortic incompetence was then evident, although pres- and the prolapsing right aortic cusp was replaced with sures recorded at the second operation showed a resi- a teflon leaflet with an excellent immediate result. dual gradient of 60 mm. Hg across the valve. The arti- Aortic incompetence soon re-appeared, however, and ficial leaflet had shrivelled and its remnant was rapidly progressed until the boy was in uncontrollable completely calcified. Pre-operatively renal function heart failure. In addition, a continuous fever was showed a reduced creatinine clearance of 63 ml./min. present and splinter haemorrhages kept appearing in on September 27, 2021 by guest. Protected and a raised blood urea of 62 mg./ 100 ml. This patient the nail beds, indicating infection, although this was tolerated the second perfusion and homograft valve never proven. At the second operation the teflon replacement extremely well without evidence of further leaflet still appeared to be functioning well, and the renal damage. incompetence was due to partial detachment of the In case 17 the first operation was performed at non-coronary cusp where it met the teflon leaflet. Green Lane Hospital in February 1963. Two of the calcified cusps disintegrated and were replaced by ASSOCIATED LESIONS Clinical assessment suggested teflon leaflets (Bahnson, Spencer, Busse and Davis, that two patients in the aortic incompetence group 1960), with a good immediate result but with the (cases 11 and 14) also had mitral incompetence that appearance within three weeks of aortic incompetence was too mild to require surgical attention. This was which gradually became very severe. At the second borne out by pressure measurements taken at opera- operation the incompetence was found to be due to tion and by the post-operative course, because after tearing of one of the teflon cusps near its attachment complete correction of the aortic leak the mitral to the aorta. incompetence became inconspicuous. In case 22, surgery had been undertaken at Green Two patients had large intrapericardial ascending Lane Hospital in 1961 when myocardial cooling with- arch aneurysms in association with aortic incom- out continuous coronary perfusion was in use. De- petence (cases 10 and 18). In both, in addition to calcification of the valve was attempted but in the inserting a homograft aortic valve, the aneurysm was Thorax: first published as 10.1136/thx.19.2.131 on 1 March 1964. Downloaded from
134 B. G. Barratt-Boyes completely excised and the aorta reconstituted by subjects up to the age of 55 years. A full sterile tech- direct end-to-end anastomosis just above the new nique was used in the majority of cases, but latterly valve. In case 10 the aneurysm was syphilitic and a number of valves have been taken by the pathologist communicated with the right pulmonary artery. This unsterile and immediately sterilized using beta- acquired aorto-pulmonary window was not suspected propiolactone (Rains, Crawford, Sharpe, Shrewsbury, for the murmur was not continuous, presumably and Barson, 1956). The valves were then placed in because the valvular incompetence was severe enough nutrient medium similar to that described by Gross, to lower aortic diastolic pressure and prevent a large Bill, and Peirce (1949), to which penicillin and strepto- left to right shunt throughout diastole. In case 18 mycin were added, and stored at 40 C. for up to a the aneurysm was probably the result of a localized week before freeze-drying. They were cultured just long-standing aortic dissection. before being placed in the medium and again on One patient (case 30) was thought to have a removal before freeze-drying: if positive they were bronchogenic carcinoma producing marked stenosis of not used. After freeze-drying, the outside of the sealed the right upper lobe bronchus and a right hilar mass. glass vacuum tube was sterilized in an ethylene oxide Bronchoscopic biopsy and sputum cytology were gas chamber at body temperature. Freeze-dried valves repeatedly negative, and, as the aortic stenosis was were reconstituted by placing them in distilled water severe, the lung lesion was treated by radiotherapy for 30 minutes and then in isotonic saline. alone, using the linear accelerator. There was con- The valves were inserted with the aid of a heart-lung siderable clearing of the hilar shadows and improve- machine of either Melrose or Kay Cross design with ment in the bronchoscopic appearances. His cardiac modifications to the venous side of the oxygenator status continued to deteriorate until frank heart failure circuit (Barratt-Boyes and Yarrow, 1961). The appeared, and at this stage-10 months after com- machine was primed with a mixture of two parts of pletion of radiotherapy-aortic valve surgery was heparinized blood (drawn on the morning of opera- performed without complications. There has been no tion) to one part of 5% glucose containing 5 g. of recurrence to date of pulmonary disease. serum albumin per 100 ml. The mediastinum was Six patients had pre-operative renal damage. This opened through a vertical sternal-splitting incision, was most marked in case 6, as already detailed, but avoiding entry into either pleural cavity. The arterial the creatinine clearance was reduced to between 60 cannula was inserted into the external iliac artery bothcopyright. and 70 ml./min. in cases 18, 36, and 37 and to to ensure as low an arterial line pressure as possible approximately 80 ml./min. in cases 3 and 41, and the and to avoid any possibility of contaminating the blood urea was also at the upper limits of normal in thoracic field from a groin incision. A single right these five patients. atrial cannula was used, except in cases 10 and 18, in the multivalvular disease group and two caval lines The six patients where both cavae were taped http://thorax.bmj.com/ all had aortic incompetence and mitral valve disease inserted: this was because previous experience had with advanced cardiac decompensation. In cases 40 and shown that a single right atrial line is dangerous in 41 there was some degree of aortic stenosis but with ascending aortic arch aneurysm where there is a pos- enough incompetence to make valve replacement sibility of holing the pulmonary artery. In case 10 it mandatory. Mitral incompetence was moderate in was fortunate that both caval tapes were in position case 39 and severe in cases 42 and 43, and in two of as there was an unsuspected aorto-pulmonary these patients it was the result of bacterial endocarditis communication. with chordal rupture. Mitral stenosis was severe in The patients were cooled to a nasopharyngeal cases 40, 41, and 44 and was associated with severe temperature of 300 C., and perfusion flow was fixed
organic tricuspid incompetence in case 44. at 2 L./m.2/min. during the cooling phase to allow on September 27, 2021 by guest. Protected the heart to contribute to the circulation in the CATHETERIZATION In eight patients preliminary cardiac expectation that body cooling would be more uniform, catheterization was undertaken for a variety of and in patients with severe aortic incompetence, to reasons: in cases 16 and 17 to exclude associated prevent overdistension of the left ventricle from mitral stenosis; in cases 3, 27, and 35 to confirm that excessive retrograde aortic flow during the cooling the aortic lesion was severe; in three of the patients phase. The aorta was cross-clamped in cases with with multivalvular disease (cases 40, 41, and 44) in an incompetence immediately there was any suggestion attempt to quantitate the severity of each lesion. of overdistension of the left ventricle, and in others Coronary angiography was not done as associated at 300 C.; it was then opened transversely about coronary artery disease was not considered a contra- 5 mm. above the origin of the right coronary artery indication to operation for severe aortic valve disease. around at least three-quarters of its circumference. Just before cross-clamping the aorta, a metal-tipped TECHNIQUE suction line was inserted through the apex of the left ventricle to empty the left heart. Suction on this line within 15 was maintained by a Sigmamotor pump, and a second Homograft aortic valves were removed also avail- hours of death. The age of the donors was limited open-heart line with a separate pump was recent able. Because of the importance in long perfusions of at first to less than 45 years, but some more the valves, for use in older patients, were taken from preventing significant haemolysis, open-heart Thorax: first published as 10.1136/thx.19.2.131 on 1 March 1964. Downloaded from
Homograft aortic valve replacement in aortic incompetence and stenosis 135 pumps were repeatedly adjusted to avoid excessive air they were liable to displacement unless further in the lines. Moreover the perfusion flow was main- secured, and this was satisfactorily achieved by a single tained at 2 l./m.2/min. until towards the end of the stitch through the aortic wall close to each coronary procedure when rewarming had been started and the orifice (Fig. 2). The two ends of the stitch were passed nasopharyngeal temperature had reached 320 C., at through a length of fine rubber tubing and, after which time flows were increased to 2.4 l./m.2/min. snuggling the end of this tubing down on to the outer In addition to keeping flows fixed at 2 L./m.2/min., as aortic wall, the plastic tubing of the coronary line soon as the aorta was cross-clamped blood was taken was held firmly against the inner aortic wall. The two from the patient into the machine until right atrial stitches, one for each coronary line, were left in pressures were negative. This manceuvre helped to place until aortic closure was almost completed. Both decompress the heart and lungs, to lessen open-heart coronary arteries were separately perfused with a return, and thus to improve operating conditions. Sigmamotor pump at a flow of 150 to 200 ml./min., When a single right atrial cannula is used and flows with monitoring of line pressures just beyond the are fixed at 2 l./m.'/min., it is of course imperative pump heads. This pressure averaged 150 to 200 mm. to have a low venous pressure if the heart is still Hg, and the coronary tips were adjusted whenever beating, otherwise some of the right atrial return will necessary to prevent a rise above 300 mm. Hg. In be pumped through the lungs and will appear in the eight patients the right coronary artery was not per- left heart field; in about half the cases the heart fused. In case 1, aged 14, the orifice was too small; continued to beat throughout the procedure. The in cases 12 and 29 it was absent; in case 21 it was patient's arterial pressure was monitored continuously, pin hole in size due to extensive fibrous thickening and in the few cases in which mean arterial pressure and calcification within the aortic wall from syphilitic fell below 70 mm. Hg during perfusion, blood was aortitis. In the other four patients (cases 17, 18, 36, returned to the patient and flows increased. Otherwise and 37), with an average age of 62 years, it was pos- blood was not returned until the rewarming phase. sible to cannulate the right coronary orifice acourately As soon as the left heart was emptied of blood, but not to perfuse the artery as line pressures imme- the left and right coronary arteries were cannulated. diately rose precipitately. It is almost certain that The blood for coronary perfusion was taken by a these arteries were blocked close to their origins. In separate line from the arterial end of the oxygenator these eight patients flow through the left coronary copyright. and was not separately filtered or cooled. The myo- cannula was increased and blood temperature was cardium was thus maintained at a temperature of dropped to approximately 27° C. approximately 300 C. Plastic coronary artery lines Placement of the coronary cannulae in the way were used with metal tips fitted with self-inflating described took only a few minutes, and further atten- rubber cuffs of Mayo Clinic design (Fig. 1). Care tion to them was seldom required. The aortic valve was taken to avoid advancing the left coronary can- was then excised. When fibrous, a peripheral cusp http://thorax.bmj.com/ nula tip too far and so perfusing only one major remnant was left: if extensively calcified, the-calcium branch of this vessel. These cannulae proved very was nibbled away carefully from the aortic wall and satisfactory as blood rarely leaked around them. ventricular outflow tract with complete removal of the During subsequent surgical manipulations, however, cusps. The homograft aortic valve was then sutured on September 27, 2021 by guest. Protected
4 -.rX A- < 2, II,* O 1 2 3 4 I ...... --I~~~~~~~~~~~~ MM. A xIG. 1. (A) Metal coronary artery perfusion tips. The left coronary tips are made in three sizes with a mushroom- shaped end: the right in two sizes with a basket tip. (B) Large left and small right coronary artery perfusion cannulae. The rubber cuffs, one of which is shown separately in the centre of the photograph, are tied over the metal tips and are automatically inflated, once the tip lies in the coronary orifice, when blood passes through the side hole beneath the cuff. L Thorax: first published as 10.1136/thx.19.2.131 on 1 March 1964. Downloaded from
136 B. G. Barratt-Boyes
FIG. 2. Coronary artery cannulae in position at operation. The transverse aortic incision is shown. The retaining suture around the right coronary cannula is in position anteriorly, but the rubber sling through which the ends of the suture have been passed is not yet tightened down onto the outside of the aorta. The left coronary cannula is also positioned with its retaining suture snugged tight. The aortic valve has been excised, giving a clear view of the anterior mitral leaflet (m). copyright. http://thorax.bmj.com/ on September 27, 2021 by guest. Protected
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.h ' '(tf r fl I ca1, i a, HOST C POSTERIOR Thorax: first published as 10.1136/thx.19.2.131 on 1 March 1964. Downloaded from Homograft aortic valve replacement in aortic incompetence and stenosis 137 r. copyright.
FIG. 4. Technique of insertion of valve. (A) The first stay suture is in place; (B) the valve is inverted down into the left ventricle and the three stay sutures are tied. The lower suture line is begun; (C) the valve is in itsfinalposition and the three highest points of the graft have been attached with the upper suture line partly completed. The insert shows how the lower suture line becomes buried when the valve is pulled upwards. http://thorax.bmj.com/ into position below the coronary ostia. The aortic three stay sutures. In case 39 this suture line was wall was trimmed from the homograft by cutting completed before it was realized that the graft had away the aortic sinuses above (Fig. 3A), leaving the been turned inside out. The sutures had to be cut aortic ring intact just below the cusps (Fig. 3B). Two out and inserted again with the graft correctly placed; continuous suture lines were used, one through the but on this second occasion the suture line presumably aortic ring below the cusps and the second following passed too close to membranous ventricular septal the line of the aortic remnant above each cusp. Un- edge for a permanent complete heart block resulted fortunately, the aortic ring below the cusps, while in this patient. on September 27, 2021 by guest. Protected fibrous posteriorly, is largely friable muscular tissue When the proximal suture line was completed the anteriorly: for this reason the homograft valve was graft was pulled upwards into its correct position rotated through 180° (Fig. 3C) so that the more (Fig. 4C) and the uppermost points of each cusp difficult anterior sutures, which bite into muscular attachment were sutured to the aortic wall just above tissue of the patient's septum, passed through the the patient's cusp remnant. The upper sutures were then fibrous aortic ring of the graft. Suturing was com- completed between these three points as continuous menced by inserting three stay sutures through the suture lines, picking up the aortic wall of the graft aortic ring of the graft beneath the most dependent at the base cf each cusp and, ideally, passing'through portion of each cusp (Fig. 4A). These sutures were the patient's cusp remnant. It was not always possible passed into the left ventricular outflow region through to use this remnant, because either the homograft corresponding points below the most dependent por- valve tended to lie better a fraction higher than.this, tions of each of the patient's excised cusps. The valve or the line of the remnant was distorted or even bi- was then lowered into position and inverted down into cuspid, or in calcified cases the valve had already the cavity of the left ventricle (Fig. 4B) so that the been completely removed. In these cases the upper aortic ring presented as the most superficial part of sutures were placed through the aortic wall above the the prosthesis; and the three sutures were tied. It cusp remnant usually at the lowest extension of each was then a relatively simple matter to complete sutur- sinus of Valsalva, as shown in Fig. 4C; although, ing the aortic ring of the graft to the host, using the when a bicuspid valve had been excised (as was the Thorax: first published as 10.1136/thx.19.2.131 on 1 March 1964. Downloaded from
133 B. G. Barratt-Boyes case in 10 patients), the homograft valve required a the homograft aortic valve was extremely difficult. completely new line of attachment dictated by the lie In cases 41, 42, and 43, a bilateral anterior thoraco- of its three cusps. With valve placement completed, tomy was used and allowed good exposure of both the aortic incision was closed with a running suture valves. This incision is not favoured, however, in started at each angle and carried anteriorly. Provided patients with advanced heart disease because of the this single suture line was kept taut, it seldom leaked, greater blood loss and greater difficulty with ventila- and additional sutures were rarely required. The tion post-operatively. In case 44, a new incision was coronary cannulae were left in position until aortic tried through the anterior half of the right fifth inter- closure was almost completed and the left heart was costal space, across the sternum at this level and verti- filled with blood. cally upwards along the left sternal edge, inside the The stage at which the heart was electrically de- internal mammary vessels, where the second, third, fibrillated depended upon the excellence of the and fourth left costal cartilages were divided without coronary perfusion. When both coronary arteries had opening the left pleura. This right antero-lateral been perfused, defibrillation was readily accomplished approach, with sternal division and the patient posi- in every instance before removing the coronary can- tioned slightly obliquely, gives surprisingly good nulae and completing aortic closure, since by this exposure of aortic, mitral, and tricuspid valves without stage the nasopharyngeal and myocardial temperatur& the disadvantages inherent in a bilateral anterior had been returned to 35° C. In these patients, once thoracotomy and is currently the approach of choice the heart was stable and blood was being ejected in multivalvular disease. through the unclosed portion of the aortic incision, In all six patients the mitral valve was approached coronary perfusion was stopped, and the cannulae from the right side and, when stenotic, was opened were removed after releasing the stay sutures around with a dilator and a knife. In case 44, because of them. Aortic closure was then rapidly completed and valvular calcification and fibrosis, incompetence was the aortic cross-clamp was released. A large-bore produced, and a Starr-Edwards ball valve (1961) was hypodermic needle was passed through the front of therefore inserted in the mitral orifice. The tricuspid the suture line to release any air trapped above the incompetence was corrected by a tricuspid annulo- valve, and the left ventricular suction line was then plasty. Of the three patients with mitral
incompetence,copyright. removed. When, however, only the left coronary artery correction was not practicable, as already noted, in had been perfused, rewarming above 32°C. was case 39; in case 42, complete correction was achieved delayed until aortic closure was completed, and the by repairing a ruptured chorda in a manner described aortic clamp was released with the heart still fibrillat- previously (Barratt-Boyes, 1963) and partially closing ing. This allowed optimum coronary perfusion from the adjacent commissure; and in case 43, a Starr-
the machine while rewarming was continued to about Edwards ball valve was inserted. http://thorax.bmj.com/ 34°C. when defibrillation was attempted and was The duration of heart-lung bypass and of coronary immediately successful in all but case 37. perfusion in each patient is listed in the Table. Case 10 In this patient, although five to 10 co-ordinated required a three-hour bypass and coronary perfusion beats followed each attempt at defibrillation, for 153 minutes, but an ascending arch aneurysm ventricular fibrillation kept recurring over a period was also resected in this patient. In most cases with of 45 minutes. Fortunately, with the aid of various aortic incompetence alone, bypass time was just under drugs, including procaine amide, electrical defibrilla- two hours; in cases with calcific stenosis it averaged tion was finally successful and a stable sinus rhythm slightly more than two hours ; and in the multivalvular was maintained thereafter. group a two-and-a-half- to three-hour perfusion was Bypass was then stopped, adding blood from the the rule. The serum haemoglobin level was measured on September 27, 2021 by guest. Protected machine until the venous pressure reached 12 to 15 spectrophotometrically at half-hourly intervals mm. Hg. After decannulation the pericardium was throughout the perfusion. The level in machine blood closed loosely over one soft rubber catheter, and a after perfusion was significantly raised in only four second catheter was placed in the anterior patients: to approximately 150 mg. in cases 3, 4, and mediastinum. 20, and to 304 mg. in case 22. In the six patients with multivalvular disease, while Post-operative management did not differ from that the homograft valve was inserted as described, a for other bypass cases. Venous and arterial pressures sternal-split chest incision was not satisfactory were monitored continuously for the first eight to because it did not permit proper exposure of the mitral 12 hours, and moderate elevation of the venous pres- valve. Thus in case 39, although the left atrium was sure was maintained. Oxygen tents were seldom used, widely opened from the right side, it was a rather and intermittent positive pressure respiration was never small chamber and the mitral valve could not be required. Additional base was not given to any patient exposed. A ruptured chorda, clearly seen from the as serial pH and carbon dioxide values were satis- aortic approach, could not therefore be repaired. In factory. Digitalis therapy was commenced or continued case 40, a right lateral thoracotomy in the fifth inter- within 12 hours of warding. The administration of costal space allowed easy cannulation of the coronary crystalline penicillin, one million units six-hourly, was arteries through the usual transverse aortotomy and continued for two weeks, and of streptomycin, 1 g. excellent exposure of the mitral valve, but suturing of daily, for four days. Anticoagulants were not used. Thorax: first published as 10.1136/thx.19.2.131 on 1 March 1964. Downloaded from Homograft aortic valve replacement in aortic incompetence and stenosis 139
Intravenous mannitol was given in eight cases as a the direct recorder showed a rapid rise in venous prophylactic measure against renal failure, and pressure followed by ventricular fibrillation. oliguria did not occur in these or in any other patient. Necropsy showed that the new valves were in an In cases 4 and 22 the only indication for its use was accurate position and the annuloplasty was intact; a raised serum haemoglobin level above 100 mg. at the cause of death. the end of bypass (Porter, Sutherland, McCord, Starr, it did not help to elucidate Griswold, and Kimsey, 1963), while in the remaining Complications in the surviving patients are listed six there was evidence, already detailed, for pre- in the Table. Pulmonary embolism occurred three operative renal damage. times and was treated successfully by several weeks' administration of anticoagulants. Two RESULTS patients had a typical post-perfusion syndrome (Kreel, Zaroff, Canter, Krasna, and Baronofsky, Forty-one of the 44 patients survived operation 1960) and one a post-cardiotomy syndrome with an apparently normally functioning homo- (Robinson and Brigden, 1963), and in case 43, who graft valve. One death occurred in each of the had bilateral anterior thoracotomies, a tracheo- three groups. stomy was required for pulmonary complications. Case 5 with aortic incompetence died within six Atrial fibrillation appeared post-operatively for hours of warding. In this patient, three pints of the first time in about one-fifth of the patients blood drained from the mediastinum during the but usually reverted spontaneously to sinus first three hours, and there was a large haematoma rhythm. One patient (case 20) developed ventri- beneath the right iliac fossa incision for insertion cular tachycardia followed by ventricular fibrilla- of the arterial cannula. The wounds were reopened tion four days post-operatively. This responded to and the bleeding points were controlled, but an prompt external cardiac massage and defibrillation hour or so later, when the blood pressure and without any brain damage or other complication. other vital signs were satisfactory and bleeding Significant post-operative morbidity occurred
had stopped, she suddenly vomited blood, inhaled only twice. In the first patient (case 6), bacterial copyright. a considerable quantity, and died soon after. endocarditis developed, the temperature showing Necropsy showed bl0od clot in the trachea and a progressive rise from the ninth to the twentieth right main bronchus but no blood in the peripheral day when a coagulase-negative Staphylococcus bronchi, and there was total collapse of the right aureus was cultured from the blood. Fortunately to upper lobe and partial lung collapse elsewhere. this organism was fully sensitive penicillin; http://thorax.bmj.com/ The stomach contained a small acute ulcer and treatment was recommenced and continued for blood, and it is assumed that this 'stress' ulcer four weeks in a dose of one million units four- was the source of the vomited blood. The homo- hourly; sodium methicillin, 1 g. four-hourly, was graft aortic valve was accurately placed and com- also given. The temperature fell quite quickly and petent, and the other heart valves were normal. there were no further positive blood cultures. Case 28, with calcific aortic stenosis, died on During this period the patient had one attack of the third post-operative day from a large full- blindness in the right eye, lasting for about one thickness infarction of the left ventricular wall minute, and subsequently had three similar epi- due to compression of the left coronary artery and sodes, the last occurring three months after opera- on September 27, 2021 by guest. Protected its two main branches by haemorrhage which lay tion but without any permanent visual field defect. outside the media. The mechanism of this bleed- As the temperature was then normal and blood ing is obscure as there was no medionecrosis of cultures were consistently negative it was assumed the wall or separation of the media, and the condi- that these were platelet emboli, and he was treated tion was therefore not a 'dissecting aneurysm'; with anticoagulants for one month. An interval nor could any communication be found between of seven months has now passed without further this blood and the vessel lumen. eye symptoms and it is nine months since anti- Case 44, with aortic and tricuspid incompetence biotics were stopped. The homograft valve con- and mitral stenosis, died on the evening of the tinues to function normally and the patient is day of surgery. This patient had very severe disease asymptomatic. One further patient (case 35) has with gross cardiomegaly (cardio-thoracic ratio had two momentary attacks of blindness which 75%). After replacement of the aortic and mitral may be due to platelet emboli, for in this patient valves and tricuspid annuloplasty the only valvular there has been no evidence of infection. The disease was slight tricuspid incompetence. His second patient with significant morbidity is case course was quite satisfactory with a normal blood 39 who, in addition to uncorrected mitral incom- pressure until 10 to 15 minutes before death when petence, has a persistent surgically induced com- Thorax: first published as 10.1136/thx.19.2.131 on 1 March 1964. Downloaded from
140 B. G. Barratt-Boyes
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A B FIG. 5. Case 1. Postero-anterior radiographs of the chest (A) immediately before operation and (B) 11 months later. copyright. plete heart block, but despite these features his murmur has seldom been heard until about one post-operative course has been smooth. An external week after operation and in some cases has sub- cardiac pacemaker was used almost continuously sequently tended to diminish in intensity. In no in the early stages and was later replaced by an patient has there been any other clinical evidence
implanted unit. Three other patients (cases 29, of residual aortic incompetence. An ejection http://thorax.bmj.com/ 36, and 42) had temporary heart block which was systolic murmur of mild to moderate intensity has probably unrelated to the suturing of the valve. invariably been present from the day of operation The follow-up period is relatively short but is but has also tended to disappear. In case 23 this now 12 months or more for the first five patients murmur was associated with a gradient of 36 mm. (cases 1 to 4 and 22). The aortic valve homograft Hg across the homograft valve (Table). This is functioning normally in all these patients, and patient had a rather small left ventricular outflow cases 1, 3, 4, and 22 are asymptomatic. The pre- and aortic ring, and the homograft valve was a operative chest radiograph and electrocardiogram little large. Despite this, however, progress has in case 1 may be compared with those taken been very favourable with complete loss of symp- on September 27, 2021 by guest. Protected approximately one year later (Figs. 5 and 6). At toms of dyspnoea, angina, and syncope, and with the time of operation this 14-year-old girl was in a rapid return of the heart size and electro- severe congestive heart failure from rapidly pro- cardiogram towards normal (Fig. 7). Case 2 gressive aortic incompetence which followed bac- requires special mention because, although the terial endocarditis. One year later there was a faint aortic incompetence has been cured (B.P. 115/90 ejection systolic murmur, a faint short early dia- mm. Hg), 10 months later there is still no reduc- stolic murmur, and normal splitting of the second tion in cardiomegaly or left ventricular hyper- heart sound; the chest radiograph and electro- trophy, and the patient has recently been admitted cardiogram were normal and the blood pressure to hospital because of recurrent congestive heart was 105/70 mm. Hg. These findings are representa- failuire. In the absence of evidence for residual tive of all the surviving patients with a sufficient valvular disease or active rheumatic fever, myo- period of follow-up except case 2. In these other cardial disease seems the probable cause of his patients the symptoms have rapidly lessened, and disappointing progress. in the aortic incompetence group in particular There have been two unexpected deaths about the heart size has rapidly diminished. About half four months after operation. Case 7, a 62-year-old the patients have a faint short early diastolic woman, had a history of severe angina decubitus, murmur maximal along the left sternal edge. This nocturnal dyspnoea, and orthopnoea. The aortic Thorax: first published as 10.1136/thx.19.2.131 on 1 March 1964. Downloaded from Homograft aortic valve replacement in aortic incompetence and stenosis14141
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FIGr. 6. Case 1. Electrocardiograms (A) before surgery, patient receiving digitalis; (B) I11 months after operation. The ST and T changes, due to left ventricular hypertrophy and digitalis effect, have disappeared. Thorax: first published as 10.1136/thx.19.2.131 on 1 March 1964. Downloaded from
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FIG. 7. Case 17. Electrocardiograms (A) before surgery, patient not receiving digitalis; (B) nine months after operation. The ST and T changes reflecting left ventricular hypertrophy have lessened considerably, although the voltage of T in V6 and VF has not yet returned to normal. Thorax: first published as 10.1136/thx.19.2.131 on 1 March 1964. Downloaded from Homograft aortic valve replacement in aortic incompetence and stenosis 143
FIG. 8. Case 7. Postero-anterior radiographs of the chest (A) two weeks before operation; note right basal pleural effusion; (B) three months later. copyright. http://thorax.bmj.com/
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FIG. 9. Case 7. Myocardial mural artery showing eccentric fibro-elastic intimal thickening. Verhoeff elastic tissue stain plus Van Gieson x 125. Thorax: first published as 10.1136/thx.19.2.131 on 1 March 1964. Downloaded from
144' B. G. Barratt-Boyes FIG. 10. Case 7. Homograft valve viewed from above. Aorta dividedjust above healed transverse aortotomy. FIG. 11. Case 7. Sagittal sections through two ofthe cusps. (A) Posterior cusp with host aortic wall above and anterior so.* _ .r t mitral leaflet (MV) below. This portion of the graft is rather bulky, partly because it contains muscular tissue below the leaflet. Elastic tissue of the aortic portion of the graft (ETG) lies inside host elastic tissue (ETH). A thick intimal sheath ofyoungfibrous tissue (IFS) starts at the base of the cusp and extends over the upper suture line onto the aortic wall. A similar layer covers a calcific nodule (arrow) presenting on the ventricular surface of the thickened mitral leaflet. Verhoeff elastic tisgue stain plus van Gieson x 2. (B) Anterior cusp. The graft is entirely fibrous and less bulky at this point. The central defect separates graft from host and is lined by young fibrous tissue. A silk suture is seen cut transversely near the lower edge ofthe graft. Th( intimalfibrous sheath above the cusp is so thin here that it cannot be clearly seen. Haematoxylin and eosin x 2. FIG. 10. copyright. http://thorax.bmj.com/
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FIG. 13. Case 7. Upper suture line of graft under higher magnification. Black-staining host elastic tisske at right, well preserved graft elastic tissue at left, and transversely cut silk suture between. The young fibrous tissue of the intimalfibrous sheath lies above with the vessel lumen in the upper left corner. Cellular reaction, consisting of macrophages and less numerous lymphocytes and fibroblasts, is most marked around the suture material and is absent in the graft-host interface deep to the suture. Verhoeff elastic tissue stain plus van Gieson x 125. Thorax: first published as 10.1136/thx.19.2.131 on 1 March 1964. Downloaded from
146 B. G. Barratt-Boyes valve was bicuspid, severely incompetent, and pain which came on at rest. Necropsy showed heavily calcified. Her post-operative course was death to be due to acute left ventricular failure uncomplicated, and when last examined three with marked pulmonary congestion and oedema. months after operation there had been a dramatic The left ventricle showed residual hypertrophy and reduction in the heart size (Fig. 8) and she was an old antero-lateral infarction. The coronary symptom-free. The blood pressure was 135/85 artery branches showed some atheromatous mm. Hg, and faint aortic systolic and diastolic narrowing but were macroscopically patent. murmurs were heard. Death occurred two weeks Microscopically, however, the majority of the later and was immediately preceded by anginal small mural arteries were narrowed by eccentric
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