N. Thorne Griscom

CT quantitation of tracheal cross-sectional area as a guide to the surgical and anesthetic management of children with anterior mediastinal masses

Pediatric patients presenting with anterior mediastinal masses between January 1980 and November 1988 were reviewed to assess the correlation between tracheal cross-sectional area and anesthetic risks. Forty-two patients had evaluable computed tomography (CT) scans and underwent a surgical procedure. Thirty-four patients had Hodgkins disease, six had non-Hodgkins lymphoma, and two had mediastinal teratoma. Tracheal cross-sectional areas were greater than 75% of expected in 19 cases, greater than 50% to 75% in 16 cases, greater than 25% to 50% in five cases, and less than or equal to 25% in two cases. The presence or extent of symptoms did not correlate well with the degree of tracheal narrowing shown by CT scan except for orthopnea. Local anesthesia was used primarily in patients with significant tracheal narrowing (tracheal size was less than or equal to 56% in 5 of 6 patients). General anesthesia with spontaneous ventilation by mask was performed in four patients with tracheal areas of 33%, 73%, 76%, and 98% of expected. General endotracheal anesthesia was utilized in the remaining 32 patients, only three of whom had tracheal areas of less than 50% of expected (down to 30%, 26%, and 24% of expected) and one received preoperative radiotherapy (26%). None of these 32 patients had symptoms of orthopnea or dyspnea at rest, and only one had dyspnea on exertion. All tolerated anesthesia without difficulty. No patient in this series suffered respiratory or cardiovascular collapse during surgery. Adequate biopsy material was obtained in all cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Lung Growth and Airway Function after Lobectomy in Infancy for Congenital Lobar Emphysema

To characterize the outcome of lobectomy in infancy and the low expiratory flows which persist after lobectomy for congenital lobar emphysema, 15 subjects with this history were studied at age 8-30 yr. Total lung capacity was normal in all, but higher values (P < 0.05) were observed in nine subjects with upper lobectomy than in five subjects with right middle lobectomy. Ratio of residual volume to total lung capacity was correlated (P < 0.05) with the amount of lung missing as estimated from normal relative weights of the respective lobes. Xe(133) radiospirometry in eight subjects showed that the operated and unoperated sides had nearly equal volumes at total lung capacity, but that the operated side was larger than the unoperated side at residual volume. Perfusion was equally distributed between the two sides. Similar findings were detected radiographically in four other subjects. Forced expiratory volume in 1 s and maximal midexpiratory flow rate averaged 72 and 45% of predicted, respectively. Low values of specific airway conductance and normal density dependence of maximal flows in 12 subjects suggested that obstruction was not limited to peripheral airways. Pathologic observations at the time of surgery and morphometry of the resected lobes were not correlated with any test of pulmonary function. These data show that lung volume can be completely recovered after lobectomy for congenital lobar emphysema in infancy. The volume increase occurs on the operated side, and probably represents tissue growth rather than simple distension. The response to resection is influenced by the particular lobe resected and may be associated with decreased lung recoil near residual volume. Low expiratory flows in these subjects could be explained by several mechanisms, among which a disproportion between airway and parenchymal growth in infancy (dysanaptic growth) is most compatible with our data.

The lung following repair of congenital diaphragmatic hernia

To determine the effects of the pulmonary hypoplasia present at birth in infants with congenital diaphragmatic hernia upon subsequent development of the lung, 19 patients who had undergone surgical repair before the age of one year were studied at ages 6 to 18 years. Total lung capacity and vital capacity averaged 99% of predicted value. Diffusing capacity for carbon monoxide was normal. Forced expiratory volume in one second averaged 89% of predicted value and 80% of vital capacity. Total respiratory system conductance and maximum expiratory flow volume curves obtained during air and helium-oxygen breathing were normal. Xenon 133 radiospirometry performed in nine patients revealed equal distribution of lung volumes on the two sides. Ventilation to the hernia side was reduced in only two patients. Blood flow to the hernia side was reduced in all nine patients. Chest radiographs supported the physiologic observations. These findings are consistent with the persistence of a reduction in the number of branches or generations of pulmonary arteries and bronchi on the side of the hernia. Since a substantial part of the vascular resistance resides in peripheral vessels, this developmental abnormality influences the distribution of pulmonary blood flow, although it has little effect on tests reflecting airway resistance or the distribution of ventilation.

Prospective evaluation by computed tomography and pulmonary function tests of children with mediastinal masses

BACKGROUNDnOur ability to predict respiratory compromise during general anesthesia in a child with an anterior mediastinal mass is limited. Two prior reports have found a correlation between adequacy of ventilation during general anesthesia and the tracheal cross-sectional area obtained from computed tomograms (computed tomography [CT] scans). These and other reports have suggested that pulmonary function tests may provide additional information regarding anesthetic risks, but no studies have evaluated the extent of respiratory compromise in children with an anterior mediastinal mass.nnnMETHODSnWe prospectively evaluated 31 children with mediastinal masses before 34 surgical procedures. At each evaluation the tracheal area (as a percent of the predicted area on the basis of age and gender) was determined by CT. Pulmonary function tests were performed in the sitting and supine positions. The eleven children with either a tracheal area or peak expiratory flow rate (PEFR) of less than 50% of predicted received only a local anesthetic; the majority of children above these levels (17 of 22) received a general anesthetic.nnnRESULTSnEleven of 31 patients had significant pulmonary restriction as defined by total lung capacity of less than 75% of predicted. Eight patients had a PEFR in the supine position of less than 50% of predicted. PEFR was lower in the supine than the upright position in all patients (median value of decrease, 12%). In 28 of 34 evaluations the child had a tracheal area greater than 50% of predicted, a criterion proposed for safe utilization of general anesthesia. This latter guideline, however, did not identify all patients with significant impairment of pulmonary function; five patients had a PEFR of less than 50% of predicted but tracheal areas of greater than 50% of predicted. All children were administered anesthetics uneventfully with these guidelines.nnnCONCLUSIONSnAlthough the tracheal area can be accurately measured with the CT scan, this does not identify all children with mediastinal masses and abnormal pulmonary function. A large mass may produce significant restrictive impairment and hence reduction in PEFR by the intrathoracic volume it occupies and yet not cause tracheal compression. It may also reduce the PEFR by narrowing the bronchi distal to the carina. Currently no CT standards exist for measuring bronchial areas in children. Our study did not evaluate whether impaired pulmonary function as measured by PEFR would be predictive of respiratory collapse during general anesthesia because all were excluded and operated on under local anesthesia. General anesthesia was well tolerated in children with tracheal area and PEFR greater than 50% of predicted. Pulmonary function tests in children with anterior mediastinal masses may add valuable information to the anatomic evaluation obtained by CT scan.

Pelvoinfundibular atresia: The usual form of multicystic kidney: 44 Unilateral and two bilateral cases

T HIS REPORT ANALYZES 44 unilateral and two bilateral cases of embryonal pelvoinfundibular atresia seen at this hospital since the late 1930s. The report attempts to answer four questions: What is the basic nature of the disease? What distinguishes it from other cystic, dysplastic, hypoplastic, and obstructive renal disorders? How may it be accurately diagnosed? What happens in the long term to children born with a kidney of this sort?

Nonskeletal malformations in one of three siblings with Jarcho-Levin syndrome of vertebral anomalies.

Trois nourrissons, nes de memes parents, presentent de multiples hemivertebres et des fusions costales compatibles avec le syndrome danomalies vertebrales de Jarcho-Levin. Lune des 2 sœurs atteintes presentait aussi une imperforation anale et un uterus didelphe. Le syndrome de Jarcho-Levin et celui decrit par Casamassima et coll. representent le meme trouble hereditaire

The medial pneumothorax.

The intrapleural air of a pneumothorax may largely collect medial to the anterior aspect of the lung in supine infants. The mechanical basis for this phenomenon is presented with supporting experimental evidence. This distribution of intrapleural air poses problems in recognition of the pneumothorax radiographically, in differentiation of the pneumothorax from pneumomediastinum, in estimation of the true volume of intrapleural air, and in the proper placement of drainage tubes. The importance of horizontal-beam lateral radiographs and of careful attention to the position of intrapleural tubes is emphasized, especially in supine, immobile newborns.

Choledochal Cysts: Roentgenographic Techniques

Twenty-four cases of choledochal cysts were reviewed. Only 7 cases were definitely diagnosed preoperatively: 3 by 131I rose bengal scanning, 2 by intravenous cholangiography, 1 by oral cholecystography, and 1 by 99mTc sulfur colloid scanning followed by angiography. The highest percentage of definitive positive examinations was found in the 131I rose bengal scan (3 of 4), but the study most helpful in suggesting the diagnosis in a general way was the upper gastrointestinal series. The more frequent use of 131I rose bengal scanning and ultrasound should increase diagnostic accuracy.

Clue to diagnosis of neonatal urinary ascites: Relative radiolucency of liver shadow

About 25 per cent of neonatal ascites is caused by urinary tract disease. Opacification of the ascitic fluid by leakage of contrast material during cystography or intravenous urography may lead to striking relative radioluency of the liver. This phenomenon may be an important clue to the differential diagnosis of the etiology of neonatal ascites.

The Visibly Fatty Liver

Fatty infiltration of the liver has been identified roentgenographically in several young children. Awareness of this possibility will sometimes allow a radiologist to contribute to the understanding of the patients metabolic and nutritional state. If a childs liver is shown to be abnormally radiolucent, cystic fibrosis should be considered.