Radiation risk to patients from percutaneous transluminal coronary angioplasty.

OBJECTIVES: This retrospective study sought to estimate patient radiation exposure during percutaneous transluminal coronary angioplasty, the corresponding organ doses and the resulting cancer mortality risk. Patient demographic data were also examined. BACKGROUND: Coronary angioplasty is commonly used as an intervention for coronary atherosclerosis, and repeated application in the same patient is now common. The combined use of fluoroscopy and cineradiography in this complicated, delicate and, hence, lengthy procedure induced us to investigate the patient radiation exposures and resulting risks. METHODS: All complete records for angioplasty procedures performed over a 3-year period were entered into a data base. The data comprised 1,893 procedures performed in a total of 1,503 patients, of whom 21% had two or more procedures in the 3-year period. Fluoroscopy time was converted to entrance exposures, assuming a rate of 520 muC kg-1 min-1 (2.0 R min-1). Cineradiographic film lengths were determined for a smaller number of procedures (200) and converted to exposures at 7.7 muC kg-1 frame-1 (30 mR frame-1). In addition, fluoroscopy and cineradiographic times and, hence, exposures for 91 diagnostic angiograms performed in these patients were obtained. Exposures were converted to organ doses using the Monte Carlo results of the Rosenstein group and then to cancer mortality risks using the latest rates of the International Commission on Radiological Protection. RESULTS: The mean age was 56.0 years; men constituted 77.5% of the patients. Radiation doses varied considerably owing to a large spread in exposure times (e.g., fluoroscopy time per angioplasty case averaged 19 min but for some cases exceeded 1 h). The average patient skin entrance exposure per angioplasty procedure was 32.0 mC kg-1 (124 R), of which 69.7% was from cineradiography. The resulting cancer mortality risk per angioplasty procedure is approximately 8 x 10(-4). CONCLUSIONS: The skin exposures estimated for angioplasty are on average higher than for other X-ray procedures. The cancer mortality risk does not exceed the mortality risk of bypass surgery. Good professional practice requires maximization of the benefit/risk ratio through quality assurance in all aspects of the procedure.

Drug treatment of the irritable bowel syndrome.

Irritable bowel syndrome (IBS) is defined as a functional bowel disorder in which abdominal pain is associated with defecation or a change in bowel habit, and with features of disordered defecation and distension. The irritable bowel syndrome occurs in 10 to 20% of people worldwide and is very commonly encountered in clinical practice. This has encouraged the pharmaceutical industry to search for effective drug therapy. So far, a universally effective agent has not been found, and since this is a chronic, benign disorder, beginning in youth, long term drug use should be avoided. Nevertheless, if a specific IBS symptom, such as constipation or abdominal pain dominates, a specific drug may be helpful. However, tests and treatment should be minimised or even avoided in order to do no harm. A largely nonpharmaceutical approach to IBS should be taken. This approach employs drugs sparingly and then only targeted at specific and resistant symptoms.

Acquired postoperative coronary arteriovenous fistula.

A patient is described who underwent closed mitral valvotomy and presented 21 years later with left ventricular failure. Coronary angiography revealed a coronary artery to pulmonary vein arteriovenous fistula. This is the first report of an acquired fistula of this type developing secondary to trauma associated with cardiac surgery. Diagnosis and treatment implications are discussed.

Peptic ulcer-induced gastroaortic fistula: difficulty in making the diagnosis with selective angiography.

We report a patient who had a gastroaortic fistula. This rare, potentially curable cause of torrential upper gastrointestinal hemorrhage is usually secondary to perforation of a gastric ulcer into the distal thoracic aorta. Hiatal hernia and previous gastroesophageal surgery (as in our patient) are important contributing factors in its genesis. It is essential to suspect this condition clinically so that the correct angiographic diagnosis can be made by biplane mid-stream thoracoabdominal aortography.

Respiratory response to formaldehyde and off-gas of urea formaldehyde foam insulation.

In 18 subjects, 9 of whom had previously complained of various nonrespiratory adverse effects from the urea formaldehyde foam insulation (UFFI) in their homes, pulmonary function was assessed before and after exposure in a laboratory. On separate occasions formaldehyde, 1 part per million (ppm), and UFFI off-gas yielding a formaldehyde concentration of 1.2 ppm, were delivered to each subject in an environmental chamber for 90 minutes and a fume hood for 30 minutes respectively. None of the measures of pulmonary function used (forced vital capacity, forced expiratory volume in 1 second or maximal midexpiratory flow rate) showed any clinically or statistically significant response to the exposure either immediately after or 8 hours after its beginning. There were no statistically significant differences between the responses of the group that had previously complained of adverse effects and of the group that had not. There was no evidence that either formaldehyde or UFFI off-gas operates as a lower airway allergen or important bronchospastic irritant in this heterogeneous population.