Influence of pulmonary vascular disease and fibrosis on prognosis following closed mitral valvotomy

Abstract

We have examined biopsies of the lingula of the upper lobe of the left lung from 85 patients undergoing mitral valvotomy and have correlated the presence of vascular changes and fibrosis of the lung tissue with pulmonary vascular resistance, the degree and type of mitral stenosis, and the duration of pulmonary symptoms. Factors which significantly affected the prognosis were high pulmonary artery pressures, high vascular resistance, and narrowing of the pulmonary arteries; but, above all, pulmonary fibrosis. The prognosis for patients with mitral incompetence was less favourable than for those without incompetence, especially if there was increased pulmonary vascular resistance and pulmonary hypertension with axis deviation in the electrocardiogram.That pulmonary vascular and parenchymal changes occur in patients with rheumatic heart disease is well established (Parker and Weiss, 1936;Evans and Short, 1957;Donald, Bishop, Wade, and Wormald, 1957;Aber and Campbell, 1965;McCredie, 1966); what is not well established is their influence on prognosis after mitral valvotomy.Larrabee, Parker, and Edwards (1949) considered that simple decompression of the engorged vessels by mitral valvotomy should be followed by early regression of such pulmonary vascular changes that had no,t become irreversible. This was supported by earlier correlations of lung biopsies with the clinical behaviour of patients after closed mitral valvotomy, which seemed to indicate that pulmonary vascular disease had little influence on prognosis (Enticknap, 1953;Denst, Edwards, Neubuerger, and Blount, 1954;Clowes, Hackel, Mueller, and Gillespie, 1953;Goodale, Sanchez, Friedlich, Scannell, and Myers, 1955); failure to achieve permanent success was ascribed largely to cardiac and not to pulmonary factors (Turner and Fraser, 1956; Woodl 1954;Learoyd, Blacket, Sinclair-Smith, Mills, Halliday, and Maddox, 1960).In order to find out, if possible, which factors were responsible for subsequent failure of the operation, and especially whether or not vascular and interstitial disease were important in this regard, the biopsy changes, and other factors ' Delivered to the General Scientific Meeting, Royal Australasian College of Surgeons, Melbourne, June 1966 which might be relevant, were correlated with subsequent death rates and with survival rates according to the presence or absence of these changes.We have studied the state of the pulmonary vessels and of the interstitial tissue of the lung in 85 unselected pulmonary biopsies excised at closed mitral valvotomy operations which were performed for the treatment of clinically diagnosed tight mitral stenosis in the period 1953-57, after which time the practice was largely discontinued; furthermore, the operation was changed to a mechanical transventricular valvotomy. MATERIAL AND METHODSLung biopsies were taken from the inflated lingular segment and all sections were examined by a single observer (V. J. McG.).Vascular changes were graded according to the degree of narrowing of the lumen, using a modificatio...