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Intravascular Pressure Measurement During Surgery
Intravascular Pressure Measurement
During Surgery AARON HIMMELSTEIN, M.D., F.A.C.S.* IVIARK M. RAVITCH, M.D., F.A.C.S.**
of the procedures done for the alleviation or correction of cardiovascular disorders create new patterns of flow. It is of interest to study the physiological changes that occur as a result of such operations, and there have been many such studies done in the early and late postoperative period. Braunwald and his associates! have summarized the reports of several authors with particular reference to the left side of the heart, including data obtained at operation. Information about the right side of the heart has been accumulating since the initial effort of Cournand and Ranges." Recordings of blood pressures in cardiac chambers and great vessels made during operation find application in establishing diagnosis and in guiding and evaluating the operative procedure. The technique is particularly useful in cases of valvular stenosis and is best illustrated by particular reference to pulmonic valvular stenosis and mitral stenosis. The physiological evidence of a stenosis is the drop in pressure through the stenotic area. Two problems arise in the interpretation of such data: First, do operating room pressures record accurately what the pressure will be after the chest is closed and the patient has recovered from the anesthesia? Second, do the changes resulting from the operative manipulation occur quickly enough in the operating room so that they reflect the status that will be present days or weeks later? We have evidence in patients with mitral stenosis and in patients with pulmonic stenosis that allow us to answer both of these questions in the affirmative, and we have some evidence of continued improvement late after operation for pulmonic stenosis. MANY
From the Department of Surgery of the Mount Sinai Hospital, Neu: York, N. Y.
* Associate in Surqeru, College of Physicians and Surgeons, Columbia [Tn'l·rersity. ** Clinical Professor of Surgery, College of Physicians and Surgeons, Columbia [Jniversity; Director, Departrnent of Surgery, Mount Sinai Hospital.
459
460
Aaron Himmelstein, Mark M. Ravitch
Patients have been studied by inserting I8-gauge, short-bevel, thinwalled needles into the chambers of the heart, the pulmonary artery and the aorta. The needles are connected by sterile heavy gauge special vinyl tubing to pressure transducers (Statham strain gauges). In our own practice the recording apparatus is such that these pressures can be visualized by the surgeon on the screen of an oscilloscope tube for operating room guidance at the same instant that they are being photographed for later study. * All pressures are usually visualized at the same zero setting and same ordinate scale. Since the same baseline is used for all tracings, gradients of pressure between adjacent chambers can be read directly. An alternate puncture technique consists of the introduction of a hollow small size Brock cardiac probe t into one chamber, advancing it into the communicating chamber or vessel while tracings are observed and recorded. In patients with pulmonic stenosis, both types of recording have been obtained in the same patient. In the ventricle an area free of coronary branches is chosen as the site of the puncture. The aorta has been cannulated either within the pericardium or just beyond the origin of the left subclavian artery. Since the site of puncture is always visualized, this means that the pericardium is opened in all cases. This experience now covers well over 40 cases. There usually is an extrasystole when the ventricular myocardium is punctured. The needles are left in place for as long as it takes to get the information desired. This may mean flushing the system with sterile fluid to obtain undamped tracings, and usually the total time required is about one or two minutes. When the needles are withdrawn, finger pressure at the site of puncture for a few minutes is adequate to control bleeding. The ventricle has not presented any problem since bleeding is only momentary. If finger pressure is maintained on the aorta for a full five minutes there will be no hematoma, but in a few instances a small hematoma has been observed to form and has been subsequently seen by x-ray. The pulmonary artery usually does not bleed as vigorously as the aorta. The auricular puncture is readily controlled by pressure. Repeat puncture is done as frequently as is necessary to obtain the information that we now use as a guide to completeness of operation. After repeated ventricular puncture we have seen only one instance in which there was electrocardiographic evidence lasting for several minutes and suggesting myocardial injury. In any hydraulic system pressure fluctuates directly with flow and resistance. Since we are usually interested in how operative intervention has changed resistance and we are using pressures as an index of this resistance, it is important that flow be as constant as possible. Care must be taken that the general condition of the patient does not change during
* Manufactured by Electronics for Medicine, White Plains, New York. t Manufactured by Sklar Instrument Company, Long Island City, New York.
I ntravascular Pressure M easurement During Surgery
4-61
the time between tracings. We usually do not measure flow in the operating room; we have assumed that if the patient's peripheral blood pressure is relatively unchanged and the clinical level of anesthesia remains the same, in general, comparisons are valid. Such assumptions seem justifiable within the range of clinical usefulness. In the normal cardiovascular system during diastole the right auricle and right ventricle are essentially one chamber and there should be no differential of pressure between them. (Actually there must be a small gradient for blood to flow.) Similarly, during systole, the pulmonary artery and right ventricle should have no gradient of pressure between
Fig. 146. Pressure recordings from the left auricle, left ventricle and aorta made at operation in a young adult who had a normal heart and was being operated on for a mediastinal cyst. Note that pressures in the auricle and ventricle are identical during diastole and that pressures in the ventricle and aorta are the same during systole.
them. The same is true of the left auricle and left ventricle during diastole and the left ventricle and aorta during systole. In Figure 146 is shown a tracing made at operation from the left side of the heart of a patient with normal cardiovascular dynamics, illustrating these observations. MITRAL STENOSIS
Mitral stenosis is usually strongly suggested by the finding of a typical diastolic murmur at the apex. Since the surgical relief of the mechanical block at the mitral valve can now be done successfully and regularly, it is of considerable importance to try to document the fact that a block exists. All surgeons who have operated for presumed isolated mitral
462
Aaron Himmelstein, Mark M. Ravitch
stenosis have been surprised by occasionally finding a strong "jet" of regurgitation and little evidence of stenosis. Pressure tracings from the left auricle may be suggestive of mitral insufficiency if there is a rather sharp peak of pressure late in systole, but significant mitral insufficiency can be present without demonstrable alteration of the tracing. The physiologic hallmark of stenosis in the cardiovascular tree is a differential of pressure on opposite sides of the stenosis. ThE greater the flow through the stenotic orifice the greater the pressure gradient must be. The material presented below in the patient with mitral stenosis shows the gradient across the mitral valve demonstrated by pressure recording
Fig. 147. Pressures recorded in a patient (J.F.) with mitral stenosis by passing a thin catheter through a needle inserted into the left auricle at bronchoscopy. The catheter was manipulated into the ventricle and then withdrawn from the ventricle into the auricle. Note the high level of pressure in the auricle as compared to the base line level in the ventricle during systole.
from the left side of the heart, obtained before operation by transbronchial auricular puncture. It is compared to similar data obtained on the operating table. Figures 147 and 148 and Table 1 are data in a 41 year old man (J.F.) whose ailment was diagnosed as mitral stenosis. His difficulty had increased progressively for the last year. The tracings in Figure 147 were made during bronchoscopy and insertion of a needle into the left auricle. Pressures were obtained by passing a polyethylene catheter through the needle and advancing it into the left ventricle. A gradient of pressure of 36 mm. Hg is seen between the left auricle and ventricle. In Figure 148, A, are tracings made at operation with needles in the left auricle and left
I ntravascular Pressure Measurement During Surgery
463
MITRAL STENOSIS (J.F:) BEFORE MANIPULATION
MM.
HG
80LEFT VENTRICLE
40LEFT AURICLE
AFTER CUTTING
AFTER FINGER FRACTURE MM.
MM.
HG
VALVE COMMISSURE
HG
60
LEFT VENTRICLE
80-
LEFT VENTRICLE
40-
40LEFT AURICLE
o-
LEFT AURICLE
o
m
[g
Fig. 148. Operating room recording of simultaneous pressures from the left auricle and left ventricle in a patient (,J.F.) with mitral stenosis. A, Before any manipulation of the valve. Compare with Figure 147. Note the gradient of pressure during diastole. B, After the valve had been open to admit one finger by finger fracture of the valve commissure. Note the drop in the gradient of pressure during diastole. C, After the valve commissure had been cut to the mitral ring. Note the complete disappearance of the gradient still present in B.
Table 1
SUMMARY OF BLOOD PRESSURES IN A CASE OF MITRAJ~ STENOSIS (J.F.) (Chamber pressures, mm. Hg) OPERATION LEFT HEART CATHETERIZATION Left auricle (mean)
43
Left ventricle (s/d)
116/3
Pulmonary artery (s /d) Left auricle to ventricle gradient (mean)
36
Before Manipulation
After First Manipulation
After Second Manipulation
23
12
95/6
86/6
87/8
41/24
29/15
25/15
17
9
0
9
Aaron Himmelstein, Mark M. Ravitch
PULMONIC STENOSIS (TB.) !!!"!!!! VALVULOTOMY MM.
!!! 140 PUJ,MOBARY
ARTERY
10/0
RIGHT VBIITJlICLE
120 100
135/15
80 80
40 -
-~6.a6~~~~J--U--U---W--:W~-\-I
20
o --
MM.
!!!
AFTSR FIRST
DILATATioN
80-
RIGHT VEBTRICLE
PULMOBARY
,58/18
ARTERY 25/12
0-.-----------------------1
MM•.
!!!
FINAL PRESSURES
80RIGHT VENTRICLE
PULMONARY 80 -
ARTERY
60/13
45/31
Fig. 149
Intravascular Pressure Measurement During Surgery
465
ventricle. A gradient of pressure of 17 mm. Hg is noted during diastole. The valve was opened by finger fracture and the tracings in Figure 148, B, were made. Because a gradient of pressure of 9 mm. Hg was still present despite the fact that the valve had been opened from a slit to one that admitted a finger easily, it was decided to cut the remainder of the fused anterior commissure. The tracings recorded in Figure 148, C, were made after this was accomplished. It shows the complete obliteration of the gradient of pressure during diastole. The pressures as recorded at left heart catheterization and at operation are summarized in Table 1. Cornrnerrt
In Table 1 it may be noted that the gradient of pressure obtained in the intact patient and at operation are of high order and indicate severe mitral stenosis. The difference is probably related to some decrease in flow in the patient during operation as compared to his preoperative state. This is further confirmed by the comparison of systolic pressures recorded in the left ventricle. The obliteration of the gradient of pressure was used as an index in the operating room to show that a more thorough opening of the stenosis was accompanied by a further physiological response toward normal. PULMONIC STENOSIS
Tracings shown were made in the operating room in a seven year old girl (T.B.) with pulmonic stenosis, before (Fig. 149, A) and after (Fig. 149, B, C) two separate series of manipulations (transventricular incision and dilatation) of the valve. In Figure 149, B, it can be seen that after the first manipulation the gradient of pressure was still considerable and therefore another larger incision and dilatation of the valve was done. There then resulted a further reduction in the gradient (Fig. 149, C). If the operator had been content with the first series of manipulations, a good clinical result might have resulted (this would be expected based on our previous experience and the results reported by others). Demonstration at the table showed that a gradient still existed, and repeated manipulations led to a further lowering of the gradient with the probability of a superior physiological result. Figure 150 shows the results obFig. 149. Operating room recordings of pressures in a patient (T.B.) with pulmonic stenosis made by passing a hollow Brock cardiac probe into the right ventricle and advancing it into the pulmonary artery. A, Before manipulation of the valve. Note the marked gradient of pressure between the pulmonary artery and right ventricle during systole. B, After the first cutting and dilatation of the valve, note that the pressure in the right ventricle has fallen and that the gradient is smaller but still quite evident. C, After a larger cut and dilatation of the valve, note that the gradient is quite small and that the ventricular pressure is much lower.
466
Aaron Himmelstein, Mark M. Ravitch
tained by right heart catheterization one and one half-years later with some further decrease in the gradient. Table 2 is a summary of the data in this case. Comment
This case illustrates that the data obtained in the intact patient agrees well with similar information obtained at operation. It also shows that the result obtained is an index of what will be true in the immediate and late postoperative period. We are guided during operation as to the thoroughness of the operation by the obliteration of the gradient in pressure between the ventricle and the pulmonary artery. An open operation through the pulmonary artery under direct vision has been
Fig. 150. Pressures recorded by right heart catheterization in patient (T.B.) 1M years after operation for pulmonic stenosis. Note that the result recorded in Figure 149, C, has persisted with some further drop in the pressure in the right ventricle.
reported by several surgeons." 4 This usually was done under hypothermia and temporary caval occlusion. These men state that only in this way can a complete operation be done every time, and quote several reports of late catheterization data to justify their point of view." We have not abandoned the early standard operation done through the ventricular myocardium. We feel that by being guided in the operating room by pressure recordings one can judge whether further and repeated manipulations are indicated, and that by repeated use of appropriate cutting instruments as reported by Johnson" one should be able to relieve the stenosis entirely. The data summarized in Table 2 also brings out the continuing improvement for a period after operation. It can be seen that the gradient is still not zero. However, this child has lost all evidence of hypertension in the right heart and all electrocardiographic evidence of right heart hypertrophy and strain. We have adopted the technique
I ntravascular Pressure Measurement During Surgery
467
initially reported by Humphreys, Brock and others, 6, 7, 8 and use pressure recordings during operation on all patients with pulmonic stenosis. Table 2
SUMMARY OF BLOOD PRESSURES IN A CASE OF PULMONIC STENOSIS (T.B.) (Chamber pressures, mm. Hg) RIGHT HEART CATHETERIZATION
OPERATION 12/2/53
Before Manipulation 4/15/53 7/6/55 Right ventricle (s/d) Pulmonary artery sid mean Right ventricle to pulmonary artery (gradient systolic)
After First Manipulation
After Second Manipulation
180/13
33/3
125/15
58/16
60/13
23/8
18/3 9
10/0
25/12
45/31
157
15
ns
33
15
SUMMARY
In our experience, simultaneous operating room pressure recordings of the gradients in mitral and pulmonic stenosis have agreed with the results of preoperative left heart and right heart catheterizations. We have been able to document and quantitate the stenosis, and serial pressures have served as a guide to the completeness of operative relief of the stenosis. Postoperative pressures obtained by catheterization accord with the final operating table pressures. With proper apparatus the pressures are quickly taken and there appears to be little or no hazard. REFERENCES 1. Braunwald, E., Moscovitz, H. L., Amram, S. S., Lasser, R. P., Sapin, S. C., Himmelstein, A., Ravitch, M. M. and Gordon, A. J.: The Hemodynamics of the Left Side of the Heart as Studied by Simultaneous Left Atrial, Left Ventricular, and Aortic Pressures; Particular Reference to Mitral Stenosis. Circulation 12: 69-81, 1955. 2. Cournand, A. and Ranges, H. A.: Catheterization of Right Auricle in Man. Proc. Soc. Exper. BioI. & Med. 46: 462, 1941. 3. Swan, H., Cleveland, H. C., Mueller, H. and Blount, S. G. Jr.: Pulmonic Valvular Stenosis. Results and Techniques of Open Valvuloplasty. J. Thoracic Surge 28: 504-511, 1954. '!. Dodrill, F. D., Hill, E., Gerisch, R. A. and Johnson, A.: Pulmonary Valvuloplasty under Direct Vision Using the Mechanical Heart for a Complete Bypass of the Right Heart in a Patient with Congenital Pulmonary Stenosis. J. Thoracic Surge 26: 584-595, 1953. 5. Johnson, J.: Discussion of Swan, H. et aI.: Pulmonic Valvular Stenosis. Results and Technique of Open Valvuloplasty. J. Thoracic Surge 28: 504-511, 1954.
468
Aaron Himmelstein, Mark M. Ravitch
6. Humphreys, G. H. II, Powers, S., Fitzpatrick, R. and Lanman, B. M.: Pulmonary Valvulotomy. Results of Operation in Twenty-Five Cases. Surgery 35: 1-8, 1954. 7. Humphreys, G. H. II: Discussion of Dodrill et al.: Pulmonary Valvuloplasty Using the Mechanical Heart. J. Thoracic Surge 26: 597, 1953. 8. Brock, R. C.: Direct Cardiac Surgery in the Treatment of Congenital Pulmonary Stenosis. Am. Surge 136: 63-72, 1952. 79 East 96th Street New York 28, N. Y. (Dr. Himmelstein)
During Surgery AARON HIMMELSTEIN, M.D., F.A.C.S.* IVIARK M. RAVITCH, M.D., F.A.C.S.**
of the procedures done for the alleviation or correction of cardiovascular disorders create new patterns of flow. It is of interest to study the physiological changes that occur as a result of such operations, and there have been many such studies done in the early and late postoperative period. Braunwald and his associates! have summarized the reports of several authors with particular reference to the left side of the heart, including data obtained at operation. Information about the right side of the heart has been accumulating since the initial effort of Cournand and Ranges." Recordings of blood pressures in cardiac chambers and great vessels made during operation find application in establishing diagnosis and in guiding and evaluating the operative procedure. The technique is particularly useful in cases of valvular stenosis and is best illustrated by particular reference to pulmonic valvular stenosis and mitral stenosis. The physiological evidence of a stenosis is the drop in pressure through the stenotic area. Two problems arise in the interpretation of such data: First, do operating room pressures record accurately what the pressure will be after the chest is closed and the patient has recovered from the anesthesia? Second, do the changes resulting from the operative manipulation occur quickly enough in the operating room so that they reflect the status that will be present days or weeks later? We have evidence in patients with mitral stenosis and in patients with pulmonic stenosis that allow us to answer both of these questions in the affirmative, and we have some evidence of continued improvement late after operation for pulmonic stenosis. MANY
From the Department of Surgery of the Mount Sinai Hospital, Neu: York, N. Y.
* Associate in Surqeru, College of Physicians and Surgeons, Columbia [Tn'l·rersity. ** Clinical Professor of Surgery, College of Physicians and Surgeons, Columbia [Jniversity; Director, Departrnent of Surgery, Mount Sinai Hospital.
459
460
Aaron Himmelstein, Mark M. Ravitch
Patients have been studied by inserting I8-gauge, short-bevel, thinwalled needles into the chambers of the heart, the pulmonary artery and the aorta. The needles are connected by sterile heavy gauge special vinyl tubing to pressure transducers (Statham strain gauges). In our own practice the recording apparatus is such that these pressures can be visualized by the surgeon on the screen of an oscilloscope tube for operating room guidance at the same instant that they are being photographed for later study. * All pressures are usually visualized at the same zero setting and same ordinate scale. Since the same baseline is used for all tracings, gradients of pressure between adjacent chambers can be read directly. An alternate puncture technique consists of the introduction of a hollow small size Brock cardiac probe t into one chamber, advancing it into the communicating chamber or vessel while tracings are observed and recorded. In patients with pulmonic stenosis, both types of recording have been obtained in the same patient. In the ventricle an area free of coronary branches is chosen as the site of the puncture. The aorta has been cannulated either within the pericardium or just beyond the origin of the left subclavian artery. Since the site of puncture is always visualized, this means that the pericardium is opened in all cases. This experience now covers well over 40 cases. There usually is an extrasystole when the ventricular myocardium is punctured. The needles are left in place for as long as it takes to get the information desired. This may mean flushing the system with sterile fluid to obtain undamped tracings, and usually the total time required is about one or two minutes. When the needles are withdrawn, finger pressure at the site of puncture for a few minutes is adequate to control bleeding. The ventricle has not presented any problem since bleeding is only momentary. If finger pressure is maintained on the aorta for a full five minutes there will be no hematoma, but in a few instances a small hematoma has been observed to form and has been subsequently seen by x-ray. The pulmonary artery usually does not bleed as vigorously as the aorta. The auricular puncture is readily controlled by pressure. Repeat puncture is done as frequently as is necessary to obtain the information that we now use as a guide to completeness of operation. After repeated ventricular puncture we have seen only one instance in which there was electrocardiographic evidence lasting for several minutes and suggesting myocardial injury. In any hydraulic system pressure fluctuates directly with flow and resistance. Since we are usually interested in how operative intervention has changed resistance and we are using pressures as an index of this resistance, it is important that flow be as constant as possible. Care must be taken that the general condition of the patient does not change during
* Manufactured by Electronics for Medicine, White Plains, New York. t Manufactured by Sklar Instrument Company, Long Island City, New York.
I ntravascular Pressure M easurement During Surgery
4-61
the time between tracings. We usually do not measure flow in the operating room; we have assumed that if the patient's peripheral blood pressure is relatively unchanged and the clinical level of anesthesia remains the same, in general, comparisons are valid. Such assumptions seem justifiable within the range of clinical usefulness. In the normal cardiovascular system during diastole the right auricle and right ventricle are essentially one chamber and there should be no differential of pressure between them. (Actually there must be a small gradient for blood to flow.) Similarly, during systole, the pulmonary artery and right ventricle should have no gradient of pressure between
Fig. 146. Pressure recordings from the left auricle, left ventricle and aorta made at operation in a young adult who had a normal heart and was being operated on for a mediastinal cyst. Note that pressures in the auricle and ventricle are identical during diastole and that pressures in the ventricle and aorta are the same during systole.
them. The same is true of the left auricle and left ventricle during diastole and the left ventricle and aorta during systole. In Figure 146 is shown a tracing made at operation from the left side of the heart of a patient with normal cardiovascular dynamics, illustrating these observations. MITRAL STENOSIS
Mitral stenosis is usually strongly suggested by the finding of a typical diastolic murmur at the apex. Since the surgical relief of the mechanical block at the mitral valve can now be done successfully and regularly, it is of considerable importance to try to document the fact that a block exists. All surgeons who have operated for presumed isolated mitral
462
Aaron Himmelstein, Mark M. Ravitch
stenosis have been surprised by occasionally finding a strong "jet" of regurgitation and little evidence of stenosis. Pressure tracings from the left auricle may be suggestive of mitral insufficiency if there is a rather sharp peak of pressure late in systole, but significant mitral insufficiency can be present without demonstrable alteration of the tracing. The physiologic hallmark of stenosis in the cardiovascular tree is a differential of pressure on opposite sides of the stenosis. ThE greater the flow through the stenotic orifice the greater the pressure gradient must be. The material presented below in the patient with mitral stenosis shows the gradient across the mitral valve demonstrated by pressure recording
Fig. 147. Pressures recorded in a patient (J.F.) with mitral stenosis by passing a thin catheter through a needle inserted into the left auricle at bronchoscopy. The catheter was manipulated into the ventricle and then withdrawn from the ventricle into the auricle. Note the high level of pressure in the auricle as compared to the base line level in the ventricle during systole.
from the left side of the heart, obtained before operation by transbronchial auricular puncture. It is compared to similar data obtained on the operating table. Figures 147 and 148 and Table 1 are data in a 41 year old man (J.F.) whose ailment was diagnosed as mitral stenosis. His difficulty had increased progressively for the last year. The tracings in Figure 147 were made during bronchoscopy and insertion of a needle into the left auricle. Pressures were obtained by passing a polyethylene catheter through the needle and advancing it into the left ventricle. A gradient of pressure of 36 mm. Hg is seen between the left auricle and ventricle. In Figure 148, A, are tracings made at operation with needles in the left auricle and left
I ntravascular Pressure Measurement During Surgery
463
MITRAL STENOSIS (J.F:) BEFORE MANIPULATION
MM.
HG
80LEFT VENTRICLE
40LEFT AURICLE
AFTER CUTTING
AFTER FINGER FRACTURE MM.
MM.
HG
VALVE COMMISSURE
HG
60
LEFT VENTRICLE
80-
LEFT VENTRICLE
40-
40LEFT AURICLE
o-
LEFT AURICLE
o
m
[g
Fig. 148. Operating room recording of simultaneous pressures from the left auricle and left ventricle in a patient (,J.F.) with mitral stenosis. A, Before any manipulation of the valve. Compare with Figure 147. Note the gradient of pressure during diastole. B, After the valve had been open to admit one finger by finger fracture of the valve commissure. Note the drop in the gradient of pressure during diastole. C, After the valve commissure had been cut to the mitral ring. Note the complete disappearance of the gradient still present in B.
Table 1
SUMMARY OF BLOOD PRESSURES IN A CASE OF MITRAJ~ STENOSIS (J.F.) (Chamber pressures, mm. Hg) OPERATION LEFT HEART CATHETERIZATION Left auricle (mean)
43
Left ventricle (s/d)
116/3
Pulmonary artery (s /d) Left auricle to ventricle gradient (mean)
36
Before Manipulation
After First Manipulation
After Second Manipulation
23
12
95/6
86/6
87/8
41/24
29/15
25/15
17
9
0
9
Aaron Himmelstein, Mark M. Ravitch
PULMONIC STENOSIS (TB.) !!!"!!!! VALVULOTOMY MM.
!!! 140 PUJ,MOBARY
ARTERY
10/0
RIGHT VBIITJlICLE
120 100
135/15
80 80
40 -
-~6.a6~~~~J--U--U---W--:W~-\-I
20
o --
MM.
!!!
AFTSR FIRST
DILATATioN
80-
RIGHT VEBTRICLE
PULMOBARY
,58/18
ARTERY 25/12
0-.-----------------------1
MM•.
!!!
FINAL PRESSURES
80RIGHT VENTRICLE
PULMONARY 80 -
ARTERY
60/13
45/31
Fig. 149
Intravascular Pressure Measurement During Surgery
465
ventricle. A gradient of pressure of 17 mm. Hg is noted during diastole. The valve was opened by finger fracture and the tracings in Figure 148, B, were made. Because a gradient of pressure of 9 mm. Hg was still present despite the fact that the valve had been opened from a slit to one that admitted a finger easily, it was decided to cut the remainder of the fused anterior commissure. The tracings recorded in Figure 148, C, were made after this was accomplished. It shows the complete obliteration of the gradient of pressure during diastole. The pressures as recorded at left heart catheterization and at operation are summarized in Table 1. Cornrnerrt
In Table 1 it may be noted that the gradient of pressure obtained in the intact patient and at operation are of high order and indicate severe mitral stenosis. The difference is probably related to some decrease in flow in the patient during operation as compared to his preoperative state. This is further confirmed by the comparison of systolic pressures recorded in the left ventricle. The obliteration of the gradient of pressure was used as an index in the operating room to show that a more thorough opening of the stenosis was accompanied by a further physiological response toward normal. PULMONIC STENOSIS
Tracings shown were made in the operating room in a seven year old girl (T.B.) with pulmonic stenosis, before (Fig. 149, A) and after (Fig. 149, B, C) two separate series of manipulations (transventricular incision and dilatation) of the valve. In Figure 149, B, it can be seen that after the first manipulation the gradient of pressure was still considerable and therefore another larger incision and dilatation of the valve was done. There then resulted a further reduction in the gradient (Fig. 149, C). If the operator had been content with the first series of manipulations, a good clinical result might have resulted (this would be expected based on our previous experience and the results reported by others). Demonstration at the table showed that a gradient still existed, and repeated manipulations led to a further lowering of the gradient with the probability of a superior physiological result. Figure 150 shows the results obFig. 149. Operating room recordings of pressures in a patient (T.B.) with pulmonic stenosis made by passing a hollow Brock cardiac probe into the right ventricle and advancing it into the pulmonary artery. A, Before manipulation of the valve. Note the marked gradient of pressure between the pulmonary artery and right ventricle during systole. B, After the first cutting and dilatation of the valve, note that the pressure in the right ventricle has fallen and that the gradient is smaller but still quite evident. C, After a larger cut and dilatation of the valve, note that the gradient is quite small and that the ventricular pressure is much lower.
466
Aaron Himmelstein, Mark M. Ravitch
tained by right heart catheterization one and one half-years later with some further decrease in the gradient. Table 2 is a summary of the data in this case. Comment
This case illustrates that the data obtained in the intact patient agrees well with similar information obtained at operation. It also shows that the result obtained is an index of what will be true in the immediate and late postoperative period. We are guided during operation as to the thoroughness of the operation by the obliteration of the gradient in pressure between the ventricle and the pulmonary artery. An open operation through the pulmonary artery under direct vision has been
Fig. 150. Pressures recorded by right heart catheterization in patient (T.B.) 1M years after operation for pulmonic stenosis. Note that the result recorded in Figure 149, C, has persisted with some further drop in the pressure in the right ventricle.
reported by several surgeons." 4 This usually was done under hypothermia and temporary caval occlusion. These men state that only in this way can a complete operation be done every time, and quote several reports of late catheterization data to justify their point of view." We have not abandoned the early standard operation done through the ventricular myocardium. We feel that by being guided in the operating room by pressure recordings one can judge whether further and repeated manipulations are indicated, and that by repeated use of appropriate cutting instruments as reported by Johnson" one should be able to relieve the stenosis entirely. The data summarized in Table 2 also brings out the continuing improvement for a period after operation. It can be seen that the gradient is still not zero. However, this child has lost all evidence of hypertension in the right heart and all electrocardiographic evidence of right heart hypertrophy and strain. We have adopted the technique
I ntravascular Pressure Measurement During Surgery
467
initially reported by Humphreys, Brock and others, 6, 7, 8 and use pressure recordings during operation on all patients with pulmonic stenosis. Table 2
SUMMARY OF BLOOD PRESSURES IN A CASE OF PULMONIC STENOSIS (T.B.) (Chamber pressures, mm. Hg) RIGHT HEART CATHETERIZATION
OPERATION 12/2/53
Before Manipulation 4/15/53 7/6/55 Right ventricle (s/d) Pulmonary artery sid mean Right ventricle to pulmonary artery (gradient systolic)
After First Manipulation
After Second Manipulation
180/13
33/3
125/15
58/16
60/13
23/8
18/3 9
10/0
25/12
45/31
157
15
ns
33
15
SUMMARY
In our experience, simultaneous operating room pressure recordings of the gradients in mitral and pulmonic stenosis have agreed with the results of preoperative left heart and right heart catheterizations. We have been able to document and quantitate the stenosis, and serial pressures have served as a guide to the completeness of operative relief of the stenosis. Postoperative pressures obtained by catheterization accord with the final operating table pressures. With proper apparatus the pressures are quickly taken and there appears to be little or no hazard. REFERENCES 1. Braunwald, E., Moscovitz, H. L., Amram, S. S., Lasser, R. P., Sapin, S. C., Himmelstein, A., Ravitch, M. M. and Gordon, A. J.: The Hemodynamics of the Left Side of the Heart as Studied by Simultaneous Left Atrial, Left Ventricular, and Aortic Pressures; Particular Reference to Mitral Stenosis. Circulation 12: 69-81, 1955. 2. Cournand, A. and Ranges, H. A.: Catheterization of Right Auricle in Man. Proc. Soc. Exper. BioI. & Med. 46: 462, 1941. 3. Swan, H., Cleveland, H. C., Mueller, H. and Blount, S. G. Jr.: Pulmonic Valvular Stenosis. Results and Techniques of Open Valvuloplasty. J. Thoracic Surge 28: 504-511, 1954. '!. Dodrill, F. D., Hill, E., Gerisch, R. A. and Johnson, A.: Pulmonary Valvuloplasty under Direct Vision Using the Mechanical Heart for a Complete Bypass of the Right Heart in a Patient with Congenital Pulmonary Stenosis. J. Thoracic Surge 26: 584-595, 1953. 5. Johnson, J.: Discussion of Swan, H. et aI.: Pulmonic Valvular Stenosis. Results and Technique of Open Valvuloplasty. J. Thoracic Surge 28: 504-511, 1954.
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Aaron Himmelstein, Mark M. Ravitch
6. Humphreys, G. H. II, Powers, S., Fitzpatrick, R. and Lanman, B. M.: Pulmonary Valvulotomy. Results of Operation in Twenty-Five Cases. Surgery 35: 1-8, 1954. 7. Humphreys, G. H. II: Discussion of Dodrill et al.: Pulmonary Valvuloplasty Using the Mechanical Heart. J. Thoracic Surge 26: 597, 1953. 8. Brock, R. C.: Direct Cardiac Surgery in the Treatment of Congenital Pulmonary Stenosis. Am. Surge 136: 63-72, 1952. 79 East 96th Street New York 28, N. Y. (Dr. Himmelstein)