Some Effects of Partial Pulmonary Valvectomy

Abstract

Partial pulmonary valvectomy was performed in 19 dogs. No change in pulmonary arterial pulse pressure was seen when less than one valvular cusp was removed; frequently no change was observed when an entire cusp was removed. Widening of the pulmonary arterial pulse pressure could be produced by removal of more than one cusp or by inducing pulmonary hypertension after removal of only one cusp. Observation as long as six months postoperatively revealed no evidence of right ventricular failure resulting from the operation. S INCE considerable regurgitation through the pulmonary valve may result from the operation for congenital pulmonary stenosis, 1 the effect upon the circulation of pulmonary valvular insufficiency is of interest. To our knowledge, this problem has not been studied experimentally, although Donovan, Hufnagel and Eastcott 2 have performed operations in which the entire output of the right ventricle was shunted through the left pulmonary artery, bypassing the pulmonary valve. This procedure produced no immediate changes in cardiac function. The development of this procedure and others, such as anastomosis of the right atrium to the pulmonary artery for the treatment of congenital tricuspid atresia, makes it desirable to study the importance of the pulmonary valve in the maintenance of the normal circulation. MATERIALS AND METHODSThe work described was done upon 27 dogs whose weights ranged from 15 to 31 Kg. The animals were anesthetized with intravenous nembutal, 25 mg. per Kg. of body weight. Positive pressure respiration was instituted through an eudotracheal tube, with intratracheal pressures from 4 to S mm. Hg. Intratracheal pressures were adjusted to the same level during cardiac pressure measurements. With the dog lying on its right side, a fourth left intercostal space incision was made. After separating the pulmonary artery and its two main branches from the aorta, a Satinsky noncrushing clamp was placed over the anterior cusp of the pulmonary ar- Supported by grants from the American Heart Association and the New York Heart Association.Received for publication July 15, 1955. tery; this cusp was then removed bloodlessly. In some instances, a portion of the right cusp was also removed or a portion of this cusp was sutured to the wall of the pulmonary artery. In two instances, the effect of inserting a glass tube through the pulmonary valve was noted. Cournand cardiac catheters, no. S or 9 in size, were inserted directly through the right ventricular and pulmonary arterial walls. These were sewn in place with purse-string sutures. Simultaneous pulmonary arterial and right ventricular pressures and, in most instances, electrocardiograms were recorded on a Sanborn Poly-Viso electrocardiograph with the aid of Statham pressure transducers or Sanborn electromanometers. Pressures were recorded at paper speeds of 50 mm. per second before and after partial valvectomy. In nine animals, the effect of pulmonary hypertension, induced either by complete occlusion of one main pulmonary artery and partial occl...

Prolonged Postsurgical Survival Without a Pulmonic Valve: Case Report and Review of the Literature

“…Experimental canine studies evaluating pulmonary valvectomy conclude that heart size, RV volume, and RV systolic pressures increase, while RV diastolic pressure and the electrocardiogram remain unchanged. 6,7 Longstanding PR can lead to severe RV dilation and decreased RV performance which leads to increased ventricular arrhythmias, poor exercise tolerance,and decreased cardiac output.…”

Pulmonary valve stenosis without ventricular septal defect: results of surgery.

“…The conclusions from stud-ies of experimental pulmonary incompetence have been contradictory. If the pulmonary valve of a dog is excised the heart enlarges, the right ventricular volume and systolic pressure rise, the diastolic pressure and electrocardiogram are unchanged, and the exercise tolerance is normal up to three years later (Kay and Thomas, 1954;Fowler, Mannix, and Noble, 1956;Ratcliffe, Hurt, Belmonte, and Gerbode, 1957). An assessment of the significance of these changes depends on whether exercise tolerance or heart size is the criterion, but a lifelong follow-up of patients with post-operative pulmonary incompetence will be needed before its importance is really known.…”