368 The Annals of Thoracic Surgery Vol 36 No 3 September 1983

Critical Pulmonary Stenosis in Infants To the Editor:

The article by Srinivasan and colleagues entitled “Critical Pulmonary Stenosis in Infants Less Than Three Months of Age: A Reappraisal of Closed Trans- ventricular Pulmonary Valvotomy” (Ann Thorac Surg 34:46, 1982) presents outstanding clinical re- sults, but a few points are unclear.

In 1980 my colleagues and I reported our experi- ence with 14 consecutive patients less than 6 months of age who underwent transventricular valvotomy for critical valvular pulmonic stenosis with no mortality [l]. Our technique was to introduce a closed mos- quito clamp through the valve and to enlarge the pas- sage by opening the clamp, gradually introducing biliary dilators up to the largest possible size for com- pletion of the valvotomy. During patient follow-up we had to reoperate on 7 of the 14 for residual valvu- lar obstruction. Five of the seven patients had various types of dysplastic pulmonary valve; their findings correlated well with the typical angiographic features of this entity.

Because the authors did not mention anything re- garding the morphological types of the pulmonic stenosis in their group of patients (e.g., dome-shaped valve, or other types), we would like them to com- ment on this point, bearing in mind that dysplastic pulmonary valves usually have nonfused commis- sures.

We question the certainty of the authors that their use of the Malm-Himmelstein valvulotome in the re-

gion of the two anterolateral commissures does in- deed perform a commissurotomy with the same pre- cision as under direct vision using cardiopulmonary bypass; and we wonder if instead it simply cuts into the cusps, thus relieving the valvular obstruction but causing the valve to regurgitate, as in 6 out of 14 of their patients. If this is possible, we would like to ask the authors if valvotomy by means of forceful dilation does less to damage the dome-shaped valve and more to preserve its competence.

It has been our experience that residual gradient following this type of procedure is directly related to the morphological type of obstruction. The results are excellent in the dome-shaped valve, but only tem- porarily satisfactory and usually requiring reopera- tion in the dysplastic and other valve types. Although we perform only closed transventricular valvotomy in infants with critical pulmonary stenosis, as do Srinivasan and associates, we do not consider this procedure curative in all patients.

Simcha Milo, M . D.

Department of Cardiothoracic Surgery Lady Davis Carmel Hospital Haifa 34 362, Israel

Reference 1. Milo S, Yellin A, Goor DA, et al: Closed pulmo-

nary valvotomy in infants under six months of age: report of 14 consecutive cases without mortal- ity. Thorax 35:814, 1980