David Dries

The economic implications of infection in cardiac surgery.

To assess the economic impact of infection, the records of 496 patients aged 18 to 82 years (mean, 61 years) undergoing open-heart operations in 1981 and 1982 were reviewed, and the costs (length of stay, hospital charges, pharmacy charges) were compared for matched pairs of patients with and without infection who had coronary artery bypass grafting (CABG) procedures. Patients received a 5-day regimen of prophylactic cephalosporin. Operative site infections occurred within 6 months of operation in 17 patients (3.4%), urinary tract infections in 9 (1.8%), and pulmonary infections in 6 (1.2%). Early and late mortality was each 2%. No deaths were infection related, and no postoperative bacterial endocarditis occurred (minimum one-year follow-up). For the matched CABG patient in whom a postoperative wound infection developed, the average length of hospital stay was 16.7 days longer and the average hospital bill was

Indium 111-labeled leukocyte scanning for detection of prosthetic vascular graft infection

8,118 greater, with the average cost to the hospital

Acute effects of argon laser on human atherosclerotic plaque

6,605 greater.

Interstitial deletion of 13q and a 13;X chromosome translocation results in partial trisomy 13 and bilateral retinoblastoma

Recent animal and human studies have suggested that positive indium 111-labeled leukocyte scans may help establish the diagnosis of vascular graft infection; however, there is little information available about the predictive value of both positive and negative leukocyte scans in larger groups of patients. In this study 31 indium 111 leukocyte scans were performed prior to definitive treatment in 21 patients with suspected vascular graft infections. Patients with more than one leukocyte scan performed had either anatomically distinct sites of infection or rescanning of a potentially infected site after definitive treatment. Scans were performed according to the method of Baker et al., attaching 500 muCi of indium 111 to leukocytes with imaging 24 hours later. All patients with positive scans underwent surgical exploration of the area of leukocyte accumulation, with documentation of purulence and culture of the graft. Patients with negative scans were treated as if scan results were indeterminate and underwent surgical exploration for usual clinical indications; if no exploration was performed, the patient was followed up closely for at least 1 year. Twelve of 12 positive scans showed purulence or culture evidence of infection with three different organisms; in 15 instances of negative scans, two operations were performed with one infection noted, whereas no patient without surgery has had a graft infection at 10 months follow-up. In addition to localizing graft infections, two scans demonstrated a nonvascular site of infection. Positive scans also helped determine the extent of infection along the graft, allowing better planning of the surgical procedure. These results indicate that indium 111-labeled leukocyte scans help document and localize prosthetic vascular graft infections.

Endoscopic laser resection of atherosclerotic plaque in a live animal model: a preliminary report on some technical difficulties

Although the laser has been demonstrated to vaporize coronary artery plaque, there is little information about its ability to resect or vaporize the range of plaques present in peripheral vessels. This study attempts to determine the ability of the argon laser to resect all grades of atherosclerotic plaque, the risk of perforation during plaque resection, the effects on surrounding arteries, and the effect of different transmission media (air, saline solution, and blood) on the delivery of laser energy to the vessel. Seventy-five adult human cadaveric aortic specimens with a range of atherosclerosis from grossly normal artery to extensive calcification with ulceration were exposed to variable energy densities (200 to greater than 20,000 J/cm2) within 48 hours of harvesting. Specimens were examined grossly for the visual effects of laser and microscopically after preparation with hematoxylin-eosin, trichrome, and/or Verhoeffs elastin stains. Our results indicate that normal arteries and noncalcified plaques absorb laser energy and are vaporized. As the atherosclerosis becomes more complex with calcification, calcified regions are not vaporized and cannot be resected. In normal arteries and noncalcified plaque, perforation times were less than 5 seconds. Where palpable calcification was present in atherosclerotic lesions, average perforation time was doubled. In some vessels areas of calcification prevented wall perforation, but areas of subintimal hemorrhage perforated rapidly because of the selective absorption of laser energy by the red color of hemorrhagic tissue. These results remain the same when saline solution is used as a transmission media, although the amount of energy required to achieve the effects is increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of argon laser on variable grades of atherosclerosis in the human aorta

Background: Abnormalities of chromosome 13 have been associated with bilateral retinoblastoma. Deletion of a retinoblastoma gene is a common primary mechanism. Other abnormalities are more rare. To our knowledge, a balanced translocation of the long arms of the X and 13 chromosomes associated with bilateral retinoblastoma has been reported five times. We report an unbalanced X;13 translocation resulting in partial trisomy 13 and an interstitial deletion of an RB locus. Methods: Case report. Results: A 19-month-old child presented with seizures to the emergency department. A CT scan revealed bilateral intraocular calcification, and retinoblastoma (RB) was confirmed with an ophthalmic exam. Abnormal facies and developmental delay were noted. A partial trisomy derived from the translocation of X;13 was observed in both bone marrow and peripheral blood cells. Fluorescence in-situ hybridization (FISH) studies confirmed triplication of a region on the q arm of chromosome 13 spanning the RB locus. One of the normal chromosome 13 homologues had an interstitial deletion of the RB locus since no signal was observed for the RB-1 probe despite the visible presence of the 13q14 region. Additional evidence of the interstitial deletion is supported by the typical facial features and developmental delay found. Presumably, the translocated X underwent X inactivation precluding systemic features typically observed in trisomy 13. Parental karyotypes were normal. The chromosomal abnormality was a de-novo constitutional event. Conclusions: Only two RB loci were present in this patient despite triplication of 13q. The third locus was deleted. We believe that the second locus was not expressed due to X inactivation of the RB gene on the der(X)t(Xq:13q) chromosome. The emergence of bilateral retinoblastoma points towards lack of heterozygosity at the third and last remaining RB loci in tumor cells. To our knowledge, an unbalanced translocation resulting in partial trisomy 13 with retinoblastoma has not been previously reported.

THE VALUE OF A 24-HOUR IMAGE (FOUR-PHASE BONE SCAN) IN ASSESSING OSTEOMYELITIS

This study was designed to determine whether laser energy could be used effectively to resect atherosclerotic plaque through an endoscope in a live animal model. Twelve adult Yorkshire swine with infrarenal aortic atherosclerosis had a 2.5 mm and/or 3.2 mm diameter fiberscope passed into the aorta from the femoral artery after proximal aortic balloon occlusion. Endoscopic argon laser resection of the atherosclerotic plaque was then attempted in eight pigs with an argon laser fiber (60 to 400 microns). We were able to visualize the raised atherosclerotic plaque in all 12 pigs with the larger 3.2 mm diameter fiberscope, which was easily passed into the aortoiliac system from the 4 mm diameter femoral vessel. The articulating end feature enhanced maneuverability within the lumen and allowed laser fiber direction. The 2.5 mm endoscope did not allow adequate visualization in any pig since the vessel could not be cleared of blood. The 2.5 mm endoscope was also passed from the femoral artery distally into the hind limb and still did not allow adequate visualization of the vessel wall because of persistent luminal blood. The 3.2 mm endoscope enabled vessel wall visualization distal to the femoral artery when the proximal artery was occluded. No aortas were grossly perforated by the laser energy. In all pigs undergoing endoscopic laser resection, raised plaques were removed both grossly and histologically, although the plaque edges were carbonized and frayed as well as vaporized. With the small spot size of the argon fiber, channels were drilled through plaque, frequently with incomplete recanalization of the lumen.(ABSTRACT TRUNCATED AT 250 WORDS)

Value of a 24-Hour Image (Four-Phase Bone Scan) in Assessing Osteomyelitis in Patients with Peripheral Vascular Disease

Laser vaporization of coronary artery plague and peripheral arterial lesions has been documented in scattered clinical and cadaver studies, but the nature of atherosclerosis present in these studies was not fully documented. This paper reviews work done in cadaver specimens of infrarenal aorta to document the response of atherosclerotic peripheral vascular lesions of variable severity to application of argon laser light. Specimens were obtained, graded for degree of atherosclerotic involvement, and treated within 48 hours of harvesting. Argon laser energy was applied using an air medium with energy densities of 200-> 20,000 J/cm2 to investigate the effects of argon light on normal and atherosclerotic aorta. Specimens were examined grossly to determine degree of atherosclerosis present and to assess effects of the laser. Light microscopy was performed after staining with Hematoxylin and Eosin, Trichrome and Verhoff’s Elastin. The studies reported herein suggest that normal and non-calcified atherosclerotic aortas are comparable and predictable in rate of penetration and perforation by argon laser light (perforation time approximates 4 seconds at 500-600 W/cm2). When calcification is present in atherosclerotic lesions, the response to laser energy is less predictable. Calcium is a general retardent of laser vaporization of tissue and penetration of aortic wall. We find that the nature of an atherosclerotic lesion may affect resectability of atherosclerosis by argon laser. The incidence and severity of potential complications including acute thrombosis or accelerated atherogenesis in treated vessels, aneurysm formation and distal embolization awaits further study in chronic animal models.Laser vaporization of coronary artery plague and peripheral arterial lesions has been documented in scattered clinical and cadaver studies, but the nature of atherosclerosis present in these studies was not fully documented. This paper reviews work done in cadaver specimens of infrarenal aorta to document the response of atherosclerotic peripheral vascular lesions of variable severity to application of argon laser light. Specimens were obtained, graded for degree of atherosclerotic involvement, and treated within 48 hours of harvesting. Argon laser energy was applied using an air medium with energy densities of 200-> 20,000 J/cm2 to investigate the effects of argon light on normal and atherosclerotic aorta. Specimens were examined grossly to determine degree of atherosclerosis present and to assess effects of the laser. Light microscopy was performed after staining with Hematoxylin and Eosin, Trichrome and Verhoff’s Elastin. The studies reported herein suggest that normal and non-calcified atherosclerotic...

The influence of harvesting technique on endothelial preservation in saphenous veins

To assess the value of 24-hour static images for Tc-99m-labeled phosphate bone scans in patients with suspected osteomyelitis, twenty-one scans on seventeen patients referred for evaluation of osteomyelitis were reviewed and correlated with surgical pathology and/or clinical course. Scan criteria for osteomyelitis were increasing lesion to background activity from 2 to 24 hours for four-phase study and from 2 to 6–8 hours for three-phase study. If lesion to background activity remained abnormal and unchanged, it was read as indeterminate; if lesion to background activity decreased, it was read as no osteomyelitis. Images were recorded on computer for normalization of count rates and intensities. Results showed that in 13 scans, there was agreement of no osteomyelitis with pathology and/or clinical course for both three and four-phase studies. In two cases of no osteomyelitis, three-phase studies were indeterminate or false/positive, while 24-hour image showed no osteomyelitis. In five proven osteomyelitis patients, four scans were positive (three and four-phase) and one was false/negative for four-phase, but positive for three-phase. Thus, in four of twenty-one scans, the 24-hour image favorably influenced the interpretation of the study; in one scan the 24-hour image was unfavorable. There was agreement between three and four-phase bone scans on sixteen of twenty-one scans. Accuracy for fourphase was 86%; three-phase was 76%.