190
CORRESPONDENCE
Ann Thorac Surg 1992;54: 187-92
Refererices 1. Hansen DE, Cahill PD, Derby GC, Miller DC. Relative contri-
2. 3. 4.
5.
butions of the anterior and posterior mitral chordae tendineae to canine global left ventricular systolic function. J Thorac Cardiovasc Surg 1987;9345-55. Komeda M, David TE, Weisel RD, Ivanov J, Burns RJ. The effects of chordal preservation on ventricular function after mitral valve replacement. Circulation 1990;82(Suppl3):481. Lillehei CW, Levy MJ, Bonnabeau RC Jr. Mitral valve replacement with preservation of papillary muscles and chordae tendineae. J Thorac Cardiovasc Surg 1964;4753243. Come PC, Riley MF, Weintraub RM, et al. Dynamic left ventricular outflow tract obstruction when the anterior leaflet is retained at prosthetic mitral valve replacement. Ann Thorac Surg 1987;43:561-3. Feikes HL, Daugharthy JB, Perry JE, Bell JH, Hieb RE, Johnson GH. Preservation of all chordae tendineae and papillary muscle during mitral valve replacement with a tilting disc valve. J Cardiac Surg 1990;5:81-5.
Modified Technique of Internal Mammary Artery Harvest To the Editor: We have read with interest the article entitled ”Modified technique of internal mammary artery harvest” by John and associates [l]. We have used this technique for the last 2 years, and have found that it reduces the time to harvest the internal mammary artery pedicle. Our technique is basically the same as described but with a slight modification. In some patients the endothoracic fascia, transversus thoracic muscle, and internal intercostal muscles are firmly attached to underlying costal cartilages, rendering it difficult to dissect the internal mammary artery without causing injury to the vessel by the electrocautery. This is especially so in the inferior portion of the dissection, overlying the fourth through seventh costal cartilages. Firmly embedded arteries are encountered in some patients with chronic obstructive pulmonary disease, in patients who have had previous episodes of costochondritis (Tietze‘s syndrome), and in some muscular individuals who have increased the length-by-width ratio of the chest cage. After palpating the internal mammary artery, we score the pedicle both medially and laterally, 1 cm away from the artery. We then infiltrate the inferior half of the pedicle from the fourth through seventh costal cartilages with a solution of one-fifth strength 1%lidocaine. This raises the pedicle from the costal cartilages and allows safer dissection of the internal mammary artery pedicle. The superior half of the dissection rarely requires the infiltration, as the pedicle and vessel can be easily separated from underlying cartilages. Pedicles harvested in this fashion demonstrated adequate flow, and harvest time was shortened considerably.
Srikrishna Sirivella, M D lsaac Gielchinsky, M D Victor Parsonnet, M D Department of Cardiovascular and Thoracic Surgey Newark Beth lsrael Medical Center 201 Lyons Ave Newark, N j 07112
Reference 1. John LCH, Edmondson SJ, Rees GM. Modified technique of internal mammary artery harvest. Ann Thorac Surg 1991;52: 157-8.
Reply
To the Editor:
We are grateful to Drs Sirivella, Gielchinsky, and Parsonnet’s comments on our article. They have specifically defined some clinical situations where traditional harvest techniques can be troublesome and the use of the modified harvest technique useful. We would like to emphasize that the modified technique has also proved to be useful in the “uncomplicated’ situation. Its principal benefit is to increase the distance between the diathermy point and the internal mammary artery, thereby minimizing trauma to the latter. This has proved to be particularly useful to surgeons in training by creating an area of “safety” for the dissection. There is just one point in their correspondence that we would question, and that is the use of lidocaine for the infiltration. Our general aim has been to use a nonirritating infiltrate, eg, normal saline solution. The potential anesthetic action of lidocaine would be short-lived, whereas there is a small risk of inadvertent intravascular injection. Apart from this we were pleased to note that other groups have also found that the modified approach produces adequate mammary arteries with a reduced harvest time.
Lindsay C . H. john, FRCS S . J. Edmondson, FRCS Gareth M . Rees, FRCS Department of Cardiothoracic Surgery St. Bartholomew’s Hospital
West Smithfield London E C l A 7BE England
Ischemic Mitral Valve Repair To the Editor: It is very gratifying to see from the recently reported Cleveland Clinic experience [ l ] that combined mitral valve operation and coronary artery bypass grafting can now be achieved with a low operative mortality and a high long-term survival. As a cardiologist who has had a long-standing dread about referring patients with coronary artery disease and ischemic mitral insufficiency to his surgical colleagues because of the uniformly high operative mortality, dismal postoperative result, and low survival, I would like to reiterate three essential points contained in the article. First, mitral valve repair is far superior to replacement and is responsible for the superior results reported by Hendren and associates (operative mortality, 9.2%). Second, the separation by Hendren and associates of ischemic mitral insufficiency due to leaflet prolapse from that due to leaflet restriction is extremely important not only as a guide to the surgical approach but also as a prognosticator for long-term survival. Valve prolapse results from papillary muscle dysfunction [2], whereas restricted leaflet motion occurs with global ventricular dysfunction [I, 21. Surgical survival was 96% for patients with mitral insufficiency with valve prolapse and 48% for those with restricted leaflet motion [l]. Third, ischemic mitral insufficiency is usually intermittent and basically a medical problem [2]. If there is serious mitral insufficiency that cannot be corrected by optimal medical therapy, then a combined valve repair and coronary artery bypass grafting
CORRESPONDENCE
Ann Thorac Surg 1992;54:187-92
operation is indicated and can be accomplished nowadays with a low operative mortality [I].
Tsung 0. Cheng, M D Department of Medicine The George Washington University Medical Center 2150 Pennsylvania Avenue, N W Washington, DC 20037
References 1. Hendren WG, Nemec JJ, Lytle BW, et al. Mitral valve repair for ischemic mitral insufficiency. Ann Thorac Surg 1991;52: 1246-52. 2. Cheng TO. Some new observations on the syndrome of papillary muscle dysfunction. Am J Med 1969;4792&45.
Acute Pulmonary Edema in Closed Mitral Commissurotomy To the Editor: Closed mitral commissurotomy is a commonly performed operation in our country as rheumatic valve disease is common in the younger age group and the procedure is inexpensive. Careful selection is done before embarking on operation as the success of closed mitral commissurotomy depends on several prerequisites such as that mitral regurgitation, atrial thrombosis, and valvular calcification are absent and chordal fusion and shortening are not severe. Unfortunately few patients satisfy all these criteria [I]. John and associates [2], in a large series of closed mitral commissurotomies, have reported 1.5% mortality in the hospital; severe mitral regurgitation developed in 0.3% of the patients. Increased operative mortality is observed in patients with mitral stenosis complicated by severe pulmonary hypertension [3]. In our practice we have seen 3 young patients with rheumatic mitral stenosis with pulmonary hypertension, without mitral regurgitation or any subvalvular pathology, undergoing closed mitral commissurotomy in whom, minutes after dilation of the valve, severe pulmonary edema, hypoxemia, bradycardia, ST-T changes, ventricular ectopy, and hypotension occurred. The surgeons felt at operation that pulmonary artery pressures were very high, but in 2 cases no mitral regurgitation was felt in the left atrium, whereas in the third a thin central jet was felt that was thought to be insignificant. These patients were resuscitated with preload reduction, inotropic support, diuretics, and intravenous morphine. Assisted ventilation with positive end-expiratory pressure of more than 12 cm H,O and a high inspired oxygen concentration was given in the intensive care unit. Swan-Ganz catheters were floated in these patients and suprasystemic pulmonary pressures were recorded that gradually leveled to preoperative values. The patients’ condition improved within 6 to 8 hours. They were extubated, and postoperative bedside echocardiography corroborated the intraoperative findings of no (in 2 cases) to insignificant (1 case) mitral regurgitation. This acute episode is baffling and difficult to explain in the absence of mitral regurgitation. In our opinion total obstruction of the mitral valve by the finger from above and the Tubbs dilator from below-which stays at mitral orifice, occluding it for 20 to 30 s e c o n d s i s the cause for this sudden severe increase in pulmonary capillary pressure, resulting in pulmonary edema. The edema appears to occur immediately after dilation, but in fact the process must have set in when the mitral orifice was obstructed. The pulmonary edema results in hypoxia, which, along with hypotension due to extremely reduced cardiac output for the transient period, results in severe global hypoxia of the myocardium, giving rise to arrhythmias and thus further aggravating the
191
hypotension. The vicious cycle sets in and can only be broken by prompt therapy. A pulmonary artery catheter is helpful during operation as pulmonary capillary wedge pressure mirrors the changes in left atrial pressure. Therefore, we conclude that even in well-selected cases, if pulmonary hypertension of even moderate degree exists closed mitral valvotomy is associated with risks of morbid pulmonary edema, and it should preferably give place to commissurotomy carried out under direct vision with the aid of cardiopulmonary bypass.
Prabhat Tewari, M D Monica Kumar, M D Department of Anesthesiology and Critical Care Medicine Sanjay Gandhi Post-graduate lnstitute of Medical Sciences PO Box 375, Raebareli Rd Lucknow. lndia
References 1. Gautam PC, Coulshed N, Epstein EJ, Llewellyn MJ, Vargas E, Tallis RC. Preoperative clinical predictors of long term survival in mitral stenosis: analysis of 200 cases followed for up to 27 years after closed mitral valvotomy. Thorax 1986;41:401-6. 2. John S, Bashi VV, Jairaj PS, et al. Closed mitral valvotomy: early results and long term follow up of 3724 consecutive patients. Circulation 1983;68:891-5. 3. Emanuel R. Valvotomy in mitral stenosis with extreme pulmonary vascular resistance Br Heart J 1963;25:119-24.
Pericardial Window To the Editor: In his Letter to the Editor, Dr Spodick [I] correctly pointed out the misnomer pericardial window, which is applied all too often to a procedure in which tube drainage of the pericardium is performed. Tube drainage is not a window. My approach to the drainage of the pericardium is the same as that of Drs Attar and McLaughlin [Z], ie, subxiphoid. Our indications include undiagnosed pericardial effusion and masses (for diagnosis), massive effusion, which is often malignant, but not necessarily (for relief), and hemorrhage after trauma (for evacuation of clots and possible treatment of heart injuries). We always excise the xiphoid process, carry out dissection between the pericardium and the diaphragm, and excise a generous piece of the pericardium, creating an opening several centimeters in diameter. This window is not closed. A drainage tube is placed in the pericardium alongside the heart for 24 hours. It is brought out through a separate stab incision. The skin incision is closed; however, the pericardial gap remains open into the subcutaneous tissue. Thus, a true window is created. To qualify for the term window, it does not have to communicate with the pleural cavity. Communication with the subcutaneous tissues aids in absorption of any transudate or exudate, and justifies the term. If Drs Attar and McLaughlin close the pericardium after its drainage, then no window has been created, and the procedure should be referred to as pericardial drainage. However, if, as in our practice, the opening is not sutured, then the term window is appropriate.
Dov Weissberg, M D Department of Surgery Tel Aviv University Sackler School of Medicine E . Wolfson Medical Center Holon, 58100 lsrael
CORRESPONDENCE
Ann Thorac Surg 1992;54: 187-92
Refererices 1. Hansen DE, Cahill PD, Derby GC, Miller DC. Relative contri-
2. 3. 4.
5.
butions of the anterior and posterior mitral chordae tendineae to canine global left ventricular systolic function. J Thorac Cardiovasc Surg 1987;9345-55. Komeda M, David TE, Weisel RD, Ivanov J, Burns RJ. The effects of chordal preservation on ventricular function after mitral valve replacement. Circulation 1990;82(Suppl3):481. Lillehei CW, Levy MJ, Bonnabeau RC Jr. Mitral valve replacement with preservation of papillary muscles and chordae tendineae. J Thorac Cardiovasc Surg 1964;4753243. Come PC, Riley MF, Weintraub RM, et al. Dynamic left ventricular outflow tract obstruction when the anterior leaflet is retained at prosthetic mitral valve replacement. Ann Thorac Surg 1987;43:561-3. Feikes HL, Daugharthy JB, Perry JE, Bell JH, Hieb RE, Johnson GH. Preservation of all chordae tendineae and papillary muscle during mitral valve replacement with a tilting disc valve. J Cardiac Surg 1990;5:81-5.
Modified Technique of Internal Mammary Artery Harvest To the Editor: We have read with interest the article entitled ”Modified technique of internal mammary artery harvest” by John and associates [l]. We have used this technique for the last 2 years, and have found that it reduces the time to harvest the internal mammary artery pedicle. Our technique is basically the same as described but with a slight modification. In some patients the endothoracic fascia, transversus thoracic muscle, and internal intercostal muscles are firmly attached to underlying costal cartilages, rendering it difficult to dissect the internal mammary artery without causing injury to the vessel by the electrocautery. This is especially so in the inferior portion of the dissection, overlying the fourth through seventh costal cartilages. Firmly embedded arteries are encountered in some patients with chronic obstructive pulmonary disease, in patients who have had previous episodes of costochondritis (Tietze‘s syndrome), and in some muscular individuals who have increased the length-by-width ratio of the chest cage. After palpating the internal mammary artery, we score the pedicle both medially and laterally, 1 cm away from the artery. We then infiltrate the inferior half of the pedicle from the fourth through seventh costal cartilages with a solution of one-fifth strength 1%lidocaine. This raises the pedicle from the costal cartilages and allows safer dissection of the internal mammary artery pedicle. The superior half of the dissection rarely requires the infiltration, as the pedicle and vessel can be easily separated from underlying cartilages. Pedicles harvested in this fashion demonstrated adequate flow, and harvest time was shortened considerably.
Srikrishna Sirivella, M D lsaac Gielchinsky, M D Victor Parsonnet, M D Department of Cardiovascular and Thoracic Surgey Newark Beth lsrael Medical Center 201 Lyons Ave Newark, N j 07112
Reference 1. John LCH, Edmondson SJ, Rees GM. Modified technique of internal mammary artery harvest. Ann Thorac Surg 1991;52: 157-8.
Reply
To the Editor:
We are grateful to Drs Sirivella, Gielchinsky, and Parsonnet’s comments on our article. They have specifically defined some clinical situations where traditional harvest techniques can be troublesome and the use of the modified harvest technique useful. We would like to emphasize that the modified technique has also proved to be useful in the “uncomplicated’ situation. Its principal benefit is to increase the distance between the diathermy point and the internal mammary artery, thereby minimizing trauma to the latter. This has proved to be particularly useful to surgeons in training by creating an area of “safety” for the dissection. There is just one point in their correspondence that we would question, and that is the use of lidocaine for the infiltration. Our general aim has been to use a nonirritating infiltrate, eg, normal saline solution. The potential anesthetic action of lidocaine would be short-lived, whereas there is a small risk of inadvertent intravascular injection. Apart from this we were pleased to note that other groups have also found that the modified approach produces adequate mammary arteries with a reduced harvest time.
Lindsay C . H. john, FRCS S . J. Edmondson, FRCS Gareth M . Rees, FRCS Department of Cardiothoracic Surgery St. Bartholomew’s Hospital
West Smithfield London E C l A 7BE England
Ischemic Mitral Valve Repair To the Editor: It is very gratifying to see from the recently reported Cleveland Clinic experience [ l ] that combined mitral valve operation and coronary artery bypass grafting can now be achieved with a low operative mortality and a high long-term survival. As a cardiologist who has had a long-standing dread about referring patients with coronary artery disease and ischemic mitral insufficiency to his surgical colleagues because of the uniformly high operative mortality, dismal postoperative result, and low survival, I would like to reiterate three essential points contained in the article. First, mitral valve repair is far superior to replacement and is responsible for the superior results reported by Hendren and associates (operative mortality, 9.2%). Second, the separation by Hendren and associates of ischemic mitral insufficiency due to leaflet prolapse from that due to leaflet restriction is extremely important not only as a guide to the surgical approach but also as a prognosticator for long-term survival. Valve prolapse results from papillary muscle dysfunction [2], whereas restricted leaflet motion occurs with global ventricular dysfunction [I, 21. Surgical survival was 96% for patients with mitral insufficiency with valve prolapse and 48% for those with restricted leaflet motion [l]. Third, ischemic mitral insufficiency is usually intermittent and basically a medical problem [2]. If there is serious mitral insufficiency that cannot be corrected by optimal medical therapy, then a combined valve repair and coronary artery bypass grafting
CORRESPONDENCE
Ann Thorac Surg 1992;54:187-92
operation is indicated and can be accomplished nowadays with a low operative mortality [I].
Tsung 0. Cheng, M D Department of Medicine The George Washington University Medical Center 2150 Pennsylvania Avenue, N W Washington, DC 20037
References 1. Hendren WG, Nemec JJ, Lytle BW, et al. Mitral valve repair for ischemic mitral insufficiency. Ann Thorac Surg 1991;52: 1246-52. 2. Cheng TO. Some new observations on the syndrome of papillary muscle dysfunction. Am J Med 1969;4792&45.
Acute Pulmonary Edema in Closed Mitral Commissurotomy To the Editor: Closed mitral commissurotomy is a commonly performed operation in our country as rheumatic valve disease is common in the younger age group and the procedure is inexpensive. Careful selection is done before embarking on operation as the success of closed mitral commissurotomy depends on several prerequisites such as that mitral regurgitation, atrial thrombosis, and valvular calcification are absent and chordal fusion and shortening are not severe. Unfortunately few patients satisfy all these criteria [I]. John and associates [2], in a large series of closed mitral commissurotomies, have reported 1.5% mortality in the hospital; severe mitral regurgitation developed in 0.3% of the patients. Increased operative mortality is observed in patients with mitral stenosis complicated by severe pulmonary hypertension [3]. In our practice we have seen 3 young patients with rheumatic mitral stenosis with pulmonary hypertension, without mitral regurgitation or any subvalvular pathology, undergoing closed mitral commissurotomy in whom, minutes after dilation of the valve, severe pulmonary edema, hypoxemia, bradycardia, ST-T changes, ventricular ectopy, and hypotension occurred. The surgeons felt at operation that pulmonary artery pressures were very high, but in 2 cases no mitral regurgitation was felt in the left atrium, whereas in the third a thin central jet was felt that was thought to be insignificant. These patients were resuscitated with preload reduction, inotropic support, diuretics, and intravenous morphine. Assisted ventilation with positive end-expiratory pressure of more than 12 cm H,O and a high inspired oxygen concentration was given in the intensive care unit. Swan-Ganz catheters were floated in these patients and suprasystemic pulmonary pressures were recorded that gradually leveled to preoperative values. The patients’ condition improved within 6 to 8 hours. They were extubated, and postoperative bedside echocardiography corroborated the intraoperative findings of no (in 2 cases) to insignificant (1 case) mitral regurgitation. This acute episode is baffling and difficult to explain in the absence of mitral regurgitation. In our opinion total obstruction of the mitral valve by the finger from above and the Tubbs dilator from below-which stays at mitral orifice, occluding it for 20 to 30 s e c o n d s i s the cause for this sudden severe increase in pulmonary capillary pressure, resulting in pulmonary edema. The edema appears to occur immediately after dilation, but in fact the process must have set in when the mitral orifice was obstructed. The pulmonary edema results in hypoxia, which, along with hypotension due to extremely reduced cardiac output for the transient period, results in severe global hypoxia of the myocardium, giving rise to arrhythmias and thus further aggravating the
191
hypotension. The vicious cycle sets in and can only be broken by prompt therapy. A pulmonary artery catheter is helpful during operation as pulmonary capillary wedge pressure mirrors the changes in left atrial pressure. Therefore, we conclude that even in well-selected cases, if pulmonary hypertension of even moderate degree exists closed mitral valvotomy is associated with risks of morbid pulmonary edema, and it should preferably give place to commissurotomy carried out under direct vision with the aid of cardiopulmonary bypass.
Prabhat Tewari, M D Monica Kumar, M D Department of Anesthesiology and Critical Care Medicine Sanjay Gandhi Post-graduate lnstitute of Medical Sciences PO Box 375, Raebareli Rd Lucknow. lndia
References 1. Gautam PC, Coulshed N, Epstein EJ, Llewellyn MJ, Vargas E, Tallis RC. Preoperative clinical predictors of long term survival in mitral stenosis: analysis of 200 cases followed for up to 27 years after closed mitral valvotomy. Thorax 1986;41:401-6. 2. John S, Bashi VV, Jairaj PS, et al. Closed mitral valvotomy: early results and long term follow up of 3724 consecutive patients. Circulation 1983;68:891-5. 3. Emanuel R. Valvotomy in mitral stenosis with extreme pulmonary vascular resistance Br Heart J 1963;25:119-24.
Pericardial Window To the Editor: In his Letter to the Editor, Dr Spodick [I] correctly pointed out the misnomer pericardial window, which is applied all too often to a procedure in which tube drainage of the pericardium is performed. Tube drainage is not a window. My approach to the drainage of the pericardium is the same as that of Drs Attar and McLaughlin [Z], ie, subxiphoid. Our indications include undiagnosed pericardial effusion and masses (for diagnosis), massive effusion, which is often malignant, but not necessarily (for relief), and hemorrhage after trauma (for evacuation of clots and possible treatment of heart injuries). We always excise the xiphoid process, carry out dissection between the pericardium and the diaphragm, and excise a generous piece of the pericardium, creating an opening several centimeters in diameter. This window is not closed. A drainage tube is placed in the pericardium alongside the heart for 24 hours. It is brought out through a separate stab incision. The skin incision is closed; however, the pericardial gap remains open into the subcutaneous tissue. Thus, a true window is created. To qualify for the term window, it does not have to communicate with the pleural cavity. Communication with the subcutaneous tissues aids in absorption of any transudate or exudate, and justifies the term. If Drs Attar and McLaughlin close the pericardium after its drainage, then no window has been created, and the procedure should be referred to as pericardial drainage. However, if, as in our practice, the opening is not sutured, then the term window is appropriate.
Dov Weissberg, M D Department of Surgery Tel Aviv University Sackler School of Medicine E . Wolfson Medical Center Holon, 58100 lsrael
