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Biomedical subjects

C C Davis

Publications and source records attributed to C C Davis.

68 records · Page 4Linked to original sources
PubMed1980

A healable filamentous Dacron surgical fabric. Experimental studies and clinical experience.

A strong, lightweight, highly compliant Dacron surgical fabric of warp-knit, velour construction has been developed as an outgrowth of research on filamentous tubular vascular prostheses. This material has excellent suturability and conformability, high preclotting efficiency, and is imprinted with calibration marks at 2 cm intervals. Experimentally, iliac artery and descending thoracic aorta patch grafts of this material were completely healed 28 days after implantation in dogs. Light and electron microscopy showed excellent healing. This paper reports clinical results of 119 patches implanted in 109 patients who have been followed for a mean of 26.4 months (range: 16--34 months). Of these, 20 patches were used in arterial reconstructions, and 99 were used in the heart for repair of 95 congenital and four acquired defects. The 20 patch angioplasties were performed in the carotid artery (four patches), subclavian artery, (one patch), common femoral artery, profunda femoris artery, or superficial femoral artery (10 patches), and in the popliteal artery (five patches). This new surgical fabric is easily adaptable to complex angioplasties and for repair of intracardiac abnormalities. No complications intrinsic to the surgical fabric have been observed in clinical use of this material in 109 patients.

Adolescent↗
PubMed1979

Axillofemoral bypass: a critical reappraisal of its role in the management of aortoiliac occlusive disease.

Two hundred twenty-four consecutive patients (361 graft limbs) who underwent bypass grafting with the USCI Sauvage filamentous velour Dacron arterial prosthesis for aortoiliac occlusive disease over the 9 year period 1970 to 1979 are reviewed. Eighty-four axillofemoral (23 percent of patients), 210 aortofemoral (47 percent of patients), and 67 femorofemoral grafts (30 percent of patients) had cumulative patency rates of 72.1, 91.1, and 86.4 percent, respectively. Experimental and clinical factors influencing the patency of axillofemoral grafts are discussed, and the concept of an improved porous Dacron prosthesis specific for the axillofemoral site is presented.

Aged↗
PubMed1979

False aneurysm of the left ventricle. Report of four cases and review of surgical management.

False aneurysms of the left ventricle were repaired in four patients (average age, 61 years). The etiology was myocardial infarction in three patients and disruption of an apical left ventricular cannulation site in the fourth. The interval from initiating event to surgery averaged 11 months. One patient was in cardiogenic shock and succumbed in the operating room from myocardial failure. The other three patients, in functional class III at the time of surgery, survived and are currently asymptomatic. The literature records 43 patients who have undergone surgical repair of a false aneurysm of the left ventricle. The causes were myocardial infarction (12 patients), operative injury (13 patients), penetrating trauma (11 patients), and blunt trauma (seven patients). Twenty-seven (63%) were under the age of 50 years. In those who were limited by symptoms, congestive heart failure predominated. Forty seven per cent of the patients were operated upon in the first five months following the initiating event; 61% within the first year. Only four patients underwent surgery more than 48 months after the myocardial insult. Thrombus was present in 28% of the aneurysms. Morbidity was recorded in nine patients, and six patients (14%) died. This study documents the necessity for early surgical repair and the relatively low operative mortality obtained with this lethal lesion.

Aged↗
PubMed1978

The preclotting of porous arterial prostheses.

A four-step preclotting method is presented for use with porous filamentous Dacron prostheses in the fully-heparinized patient. The method employs controlled fibrin formation within graft interstices, heparin neutralization of all thrombin remaining in the graft wall, and delay of systemic heparin neutralization until 15--20 minutes after clamp release. The resulting flow surface is impervious, smooth and hypothrombogenic. Experimental data are presented which support the rationale of this four-step preclotting method. Four years of clinical experience with the method are summarized, involving 300 prosthesis limbs used in aortic bifurcation, aortofemoral, femorofemoral, axillary-femoral and femoropopliteal positions in 192 patients. A clinical perspective of preclotting techniques is presented in which the proper use of this new method is suggested.

Animals↗
PubMed1978

Measurements of cardiac output in seriously ill patients using a CO2 rebreathing method.

A CO2 rebreathing method for the measurement of cardiac output was evaluated by comparison with the direct Fick O2 method in 26 studies performed in 18 patients who were critically ill. The method requires measurement of CO2 output by collection of expired gas, of arterial PCO2, and of mixed venous PCO2 by rebreathing. Twenty-five comparisons were within +/- 20% of the direct Fick measurements, at cardiac outputs varying between 1.4 and 6.4 L/min. Knowledge of the cardiac output increased the quality of the interpretation of arterial blood PO2 measurements in the assessment of pulmonary gas exchange disturbances.

Blood Gas Analysis↗
PubMed1978

Replacement of ruptured chordae tendineae of the mitral valve with autologous pericardial chordae.

Severe mitral regurgitation owing to rupture of chordae tendineae has been repaired in 10 patients by construction of new chordae from autologous pericardium. The site of rupture was the posterior leaflet in eight patients, the anterior leaflet in one patient, and both leaflets in one patient. Cardiac catheterization demonstrated severe mitral regurgitation (average 49%) and a left atrial V wave of 45 mm. Hg. The reconstruction was carried out with pericardium rolled into a chorda with one end attached to the appropriate papillary muscle and the other attached to the flail edge of the mitral valve leaflet being repaired. One patient died on the seventh postoperative day from pneumonia. The remaining nine patients are alive and well (Functional Class I) from 6 months to 9 1/2 years (average 3 years) following the operation. None requires anticoagulants.

Aged↗
PubMed1977

Geometric comparison of aortic bifurcation prostheses to the normal and atherosclerotic human aorta, and clinical trial of a vertical seamed bifurcation prosthesis.

The 12 bifurcation prostheses generally available in the United States were compared. One was woven Teflon, two woven Dacron, and nine knitted Dacron. Ten were "seamless" in construction, and two were "seamed," but close examination revealed that all prostheses actually were seamed at the bifurication point. The grafts varied considerably in construction, porosity, and geometry. To compare the geometries, each prosthesis was preclotted in plasma, inflated to 120 mm. Hg, and quick frozen in alcohol and dry ice. Transverse and frontal bisections of the frozen specimens were photographed with a millimeter scale for sizing. For comparison, eight human aortofemoral bifurcations were distended and frozen similarly. The prostheses had far wider bifurcation shelves than did the normal aortas. The five normal human aortofemoral bifurcations had an average ratio of limb: body diameter of 0.61; the three atherosclerotic specimens averaged 0.49. The prostheses had an average limb:body diameter ratio of 0.48. or the "seamless" grafts, 0.48 for the circular transverse limb-seamed grafts, and 0.58 for the vertical-seamed grafts. Vertical-seamed aortic bifurcation grafts implanted in 102 patients between 1970 and 1976 (average follow-up, 29.5 months) have developed only a single limb closure, at 53 months.

Aorta↗
PubMedDate not supplied

Near-field second harmonic imaging of lead zirconate titanate piezoceramic.

Near-field optical microscopy has been used to image variations in local optical second harmonic generation (SHG) from the surface of lead zirconate titanate (PZT) piezoceramic. As PZT ceramic is a strongly scattering medium. SHG occurs in the thin layer near the surface of the ceramic. Thus, individual crystalline grains and grain boundaries located near the surface are the main features visible in the images. In general, this technique allows us to determine the local poling direction of individual submicrometre-sized crystalline grains of ceramic by near-field SH imaging at different angles of incidence and polarization states of the fundamental excitation light. In some cases 'hot spots' of submicrometre size showing enhanced SHG have been observed. This enhancement is believed to result from local cavity resonances.

Journal Article↗
PubMedDate not supplied

Near-field imaging of surface-enhanced second harmonic generation.

Surface-enhanced second harmonic generation from individual topographical defects of an otherwise flat gold film and from metal-coated diffraction gratings was measured using a near-field optical microscope. Experimentally measured second harmonic field distributions were compared with theoretical calculations.

Journal Article↗