Successful treatment of plastic bronchitis with low fat diet and subsequent thoracic duct ligation in child with fontan physiology.

Plastic bronchitis is a rare condition characterized by the formation and expectoration of long, branching bronchial casts that develop in the tracheobronchial tree and cause airway obstruction. Plastic bronchitis has become increasingly recognized as a feared complication of the Fontan operation with a mortality of up to 50%. We report an 11 year old boy who developed severe plastic bronchitis following Fontan repair and the successful long-term control of cast formation utilizing a low-fat diet and subsequent thoracic duct ligation.

Third-degree burns due to intraoperative use of a Bair Hugger warming device.

We report the case of a 3-year-old boy who underwent correction of transposition of the great arteries who developed burns from use of a patient warming device. His repair had been delayed because he was from a developing country, and he was offered surgery as part of a humanitarian effort. Postoperatively he was noted to have second- and third-degree burns from use of a Bair Hugger (Augustine Medical, Eden Prairie, MN) warming system after cardiopulmonary bypass.

Experimental determination of mechanical shear stress about an anastomotic junction.

The present study is undertaken to determine whether the elastic tube model originally developed by Kuchar and Ostrach (Biomedical Fluid Mechanics Symposium, pp. 45-69, 1966) accurately provides a first approximation of the biomechanics of the anastomotic junction. The experimental protocol involves the use of canine carotid arteries as the host vessel and several graft materials including autogenous and prosthetic substitutes. The host artery-graft combinations are perfused in vitro in a pulsatile perfusion apparatus which simulates the natural hemodynamic environment. This apparatus provides accurate dynamic measurements of radial wall motion (measured at various longitudinal increments), associated pressures and rates of fluid flow. These data are then applied to the theoretical model for calculation of anastomotic induced bending stresses. The results indicate that the predictions derived from the elastic model consistently overestimate the measured radial change adjacent to the anastomotic junction. As a result shear stresses based on elastic theory deviate from values derived from a numerical curve fit to the experimental data.

Effect of variations in pressure and flow on the geometry of isolated canine carotid arteries.

A study is described in which the effects of hemodynamics on arterial geometry are investigated in vitro. A novel perfusion apparatus is employed to deliver pulsatile flow through excised canine carotid arteries under carefully controlled conditions. Data of perfused vessel diameter and arterial wall thickness are derived from the radial displacement of the pulsating vessel as measured using a scanning laser micrometer whose accuracy is determined to be 0.0125 mm (0.0005 in). The results of 30 perfusion experiments suggest that the hemodynamic variables of transmural pressure, pulse pressure and flow rate influence vessel size and radial strain. The physiologic implications of these findings are discussed.

Characterization in vitro of the biomechanical properties of anastomosed host artery-graft combinations.

An in vitro investigation is described in which the biomechanical properties of several host artery-graft combinations are characterized under realistic hemodynamic environments. Canine carotid arteries served as the host vessel and were anastomosed to one of the following graft materials: 4 mm I.D. thin-walled expanded polytetrafluoroethylene (e-PTFE), 6 mm I.D. thin-walled e-PTFE, modified human umbilical vein, autogenous foreleg vein, and carotid artery. A novel feature of the experimental design is the use of a pulsatile perfusion apparatus that simulates realistic normotensive or hypertensive hemodynamics, including pulse rate, perfusion pressure, and flow rate. Measurements of dynamic transmural pressure and vessel radial motion (determined with a helium-neon laser micrometer) were obtained during pulsatile perfusion. From these data calculation of the mismatch in diameter and elasticity modulus between the host carotid artery and various graft materials is made. The longitudinal propagation of the non-uniform radial displacement associated with the construction of the anastomotic junction is also calculated and presented. The present methodology is directly applicable to testing of other vascular substitutes and provides repeatable and reliable biomechanical data.

Streptokinase in the treatment of subclavian vein thrombosis.

During the past 2 years, streptokinase has been used to treat subclavian or axillary vein thrombosis in seven patients of whom two were considered "effort" thromboses and five resulted from use of a central venous catheter. All patients had venography performed before treatment to document the thrombosis, and venography was repeated after streptokinase therapy to determine the status of clot dissolution. Streptokinase was given either systemically or in a lowered dose locally, with low-dose therapy chosen whenever a catheter could be threaded up to the clot through an antecubital vein. Although all seven patients had resolution of their clinical symptoms, only one had complete dissolution of the thrombus. The failure of streptokinase to completely dissolve the thrombus suggests that, although apparent clinical improvement can be achieved after streptokinase infusion, treatment of the underlying cause, whenever possible, may be necessary if complete resolution of the thrombus is to occur.

Use of autoperfusion for distant procurement of heart-lung allografts.

Heart-lung transplantation has been limited to on-site organ procurement because current methods of lung preservation are unreliable for periods in excess of one hour. A method of dynamic heart-lung preservation has been evaluated as a possible means for distant procurement for human transplantation. Canine and bovine heart-lung blocks were removed and preserved by autoperfusion for periods of two to nine hours. The key features of the method included normothermic coronary autoperfusion with donor blood by an autoregulating beating heart, and a stabilizing reservoir bag interposed between the donor aorta and the right atrium. The reservoir is positioned one meter above the aortic valve, and determines the pressure in the aorta. Flow from the bag to the right heart dictates venous return, pulmonary blood flow, and ventricular stroke volume. The lungs are ventilated with room air and 5% to 10% of CO2, at 4 liters/minute. Normothermia is ensured by immersion of the heart-lungs block in a temperature controlled crystalloid bath. Eleven canine and eight bovine heart-lung blocks were evaluated for two to nine hours. Lung function was excellent during this period, and cardiac output did not decline from pre-harvest levels. Five heart-lung allografts were transplanted after an average of four hours of autoperfusion and all functioned satisfactorily. All animals could be weaned from the extracorporeal circulation support. Two to three hours later, cardiac outputs and arterial pO2 were normal. The peak airway pressures averaged 29 cm H2O.(ABSTRACT TRUNCATED AT 250 WORDS)