The role of inflammation in bronchial stump healing.

The roles of inflammatory response and closure technique in the development of bronchopleural fistula were evaluated. Canine bronchial stumps closed with 3-0 silk and studied 14 days later were characterized by a dense inflammatory infiltrate. Stumps closed with 3-0 chromic catgut suture showed a moderate inflammatory response with disintegration of suture material. However, stumps closed with the automatic stapling device (TA-30) showed the best healing and a minimal degree of inflammation. These findings correlated well with leakage pressures. The average leakage pressure for the silk closed stumps was 139.44 mm Hg plus or minus 78.9 SD. This was significantly lower (P less than 0.02) than the average leakage pressure for staple closed stumps (251.25 mm Hg plus or minus 82.9 SD). It is concluded that the minimal amount of inflammation following staple closure will be associated with improved bronchial stump healing and a lower incidence of bronchopleural fistula.

Comparative evaluation of artificial ventricles in the United States.

A cooperative, comparative evaluation of nine artificial ventricles was performed on two standardized mock circulations. The ventricles included five air-driven diaphragm types, three sack types and a mechanically driven type. The slopes of the ventricular output curves varied from 0.04 to 0.88 at 0 to 5 Torr filling pressure and the maximum ventricular output varied from 3.8 to 11.9 liters/min at 100 Torr outflow pressure. All ventricles had decreased output with increased outflow pressures (70 to 130 Torr). Hemolysis index ratio (HI test/HI std) for HI std equals 0.024 plus or minus .005 (plus or minus 1 SD) g/100 liters (N equals 12), was +21.5 and +6.9 for a Dacron cloth and fibril heart, respectively, +2.0 to +2.86 for three sack ventricles, and +3.2 for a smooth diaphragm ventricle. The mechanical ventricle with a sinusoidal driving waveform and smooth surface had the lowest hemolysis, HI equals 0.008 plus or minus 0.003 (plus or minus 1 SD) (N equals 6). Sack ventricles caused marked hemolysis if the walls touched during systole. Ventricular dimensions varied: weight 116 to 700 g, length 9.2 to 18.7 cm, and volume 235 to 430 ml. Performance data was returned to each individual laboratory which resulted in modification of ventricular design in at least three instances. Comparative, standardized testing of artificial ventricles may shorten development time and provide performance criteria for application in man.