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

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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

Acute pulmonary edema in closed mitral commissurotomy.

CORRESPONDENCE Ann Thorac Surg 1992;54:187-92 operation is indicated and can be accomplished nowadays with a low operative mortality [I]. Tsung 0...
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