Search PubMed⌕ Search

Biomedical subjects

C B Wright

Publications and source records attributed to C B Wright.

At least 55 records · Page 3Linked to original sources
PubMed1982

Determination of coronary reserve in patients with supravalvular aortic stenosis.

Coronary reserve in patients with supravalvular aortic stenosis may be limited by coronary artery ostial obstruction or left ventricular hypertrophy. To assess the relative effect of these two factors on coronary reserve, seven patients with supravalvular aortic stenosis were studied intraoperatively before and after repair. Six patients who underwent elective cardiac surgery for conditions that did not involve the left ventricle or the left anterior ascending coronary artery served as controls (control group 1). Four patients were studied before and after cardiopulmonary bypass to determine if cardiopulmonary bypass altered coronary reserve in normal vessels perfusing normal ventricle (control group 2). Using a pulsed Doppler probe to determine coronary velocity, coronary reactive hyperemia was induced in the left anterior descending coronary artery (patients with supravalvular aortic stenosis and group 1 controls) or right ventricular branches of the right coronary artery (group 2 controls) during maximal coronary dilation produced by a 20-second coronary occlusion. All patients with supravalvular aortic stenosis underwent patch aortoplasty to relieve left coronary artery ostial obstruction and outflow tract obstruction; three patients also underwent aortic valvotomy and one patient also underwent valve replacement. Coronary reactive hyperemia was calculated as the ratio of peak to resting velocity. This ratio was 5.0 +/- 0.6 (mean +/- SEM) preoperatively and 3.6 +/- 0.3 postoperatively in control group 2. Thus, coronary reserve was only modestly reduced after cardiopulmonary bypass. Before repair, the ratio of peak to resting velocity was markedly reduced in patients with supravalvular aortic stenosis compared with control group 1 (1.8 +/- 0.3 vs 4.9 +/- 0.5, p less than 0.05) and did not change after repair (1.7 +/- 0.2), even though the aortic gradient was reduced (80 +/- 14 vs 38 +/- 6 mm Hg, p less than 0.05) and real or potential coronary ostial obstruction was eliminated by the operation. Because coronary reserve did not improve after surgery in patients with supravalvular aortic stenosis, we conclude that left ventricular hypertrophy is probably the primary determinant of decreased coronary reserve in these patients.

Adolescent↗
PubMed1981

Tined transvenous endocardial electrodes: results of a randomized prospective study.

The early (30-day) dislodgment rate of standard-use flange-tipped and of tined endocardial electrodes was compared in a randomized prospective clinical trial. Four of 16 (25%) of the flange-tipped leads and none of the 18 tined leads dislodged within 30 days of implantation (p = 0.01). We believe that the tined electrode represents a major improvement in electrode design and is clearly superior to the flange-tipped electrode in reducing the incidence of early dislodgment.

Clinical Trials as Topic↗
PubMed1981

Oculopneumoplethysmography, Doppler examination, and supraorbital photoplethysmography: a comparison of hemodynamic techniques in assessing cerebrovascular occlusive disease.

There noninvasive techniques used in the evaluation of carotid occlusive disease were compared in the same population group. The cerebrovascular Doppler examination (CDE) had an accuracy rate of 89%, oculopneumoplethysmography (OPG-Gee) an accuracy rate of 94%, and supraorbital photoplethysmography (SOPPG) an accuracy rate of 86%. With the combined use of the CDE and the OPG-Gee, the accuracy rate increased to 96% when the results were concordant, and the false-negative rate dropped to 3%. The data would suggest that the combined use of the CDE and the OPG-Gee offers an advantage over either technique used individually.

Arterial Occlusive Diseases↗
PubMed1980

Convulsions after carotid endarterectomy.

Convulsions have not been emphasized as a possible complication of carotid endarterectomy. We describe here three patients in whom seizures with a focal component developed postoperatively. We suspect that the convulsions were secondary to a cerebral embolus arising from the operative site. An unstable preoperative neurological status is not a prerequisite for this complication.

Aged↗
PubMed1980

Esophageal atresia and tracheoesophageal fistula.

Fifty-seven babies were surgically treated for esophageal atresia and tracheoesophageal fistula between 1968 and 1978. Forty-eight (84%) had proximal esophageal atresia and a distal tracheoesophageal fistula, 2 (4%) had proximal and distal esophageal atresia and no tracheosophageal fistula, and 7 (12%) had a tracheosophageal fistula without esophageal atresia. Primary repair was accomplished in 43 patients (75%), colon interposition was required in 5 (9%), while the remainder had staged or palliative reapirs. Forty-six (81%) survived surgical treatment. All 21 babies in Waterston Category A, 90% of 20 in Category B, and 44% of 16 in Category C survived surgical treatment. Serious complications occurred in 17 (30%), and dilatable strictures and other minor problems developed in 27 (47%). Late follow-up (mean, 48 months) revealed 3 (7%) late deaths, 2 of which were due to congenital heart disease. Three patients required late colon interposition, and several require frequent dilatations of the esophagus. The Category A and B survivors are all functionally well, while the 5 surviving Category C patients are all significantly impaired by associated anomalies.

Child, Preschool↗
PubMed1980

Surgical treatment of left main coronary artery disease: operative risk.

Surgical experience with 100 consecutive patients with left main coronary artery stenosis (greater than 50%) was reviewed to determine the risk factors and their relationship to preoperative use of intraaortic balloon (IAB). The 30-day mortality rate was 3% and the perioperative infarction rate was 2%. There was no correlation between surgical mortality and ejection fraction (EF) (15% had EF of less than 40%), degree of stenosis (58% of the patients had greater than 70% left main stenosis), right coronary artery stenosis (81%), or the number of grafts placed. We conclude that surgery for left main coronary artery disease can be done with a low mortality rate by strict attention to the induction of anesthesia, surgical technique, and complete revascularization. In our experience, prophylactic use of the IAB does not appear to be justified and is only rarely necessary for postoperative support (one case).

Adult↗
PubMed1980

Distal reconstruction following aortobifemoral bypass grafting: predictability by early hemodynamic result.

Controversy exists concerning the usefulness and accuracy of immediate postoperative ankle-arm indexes in predicting the need for distal reconstructive procedures following aortobifemoral bypass grafting. To evaluate this concept, preoperative, immediate postoperative, and late postoperative ankle-arm indexes were calculated for 20 patients (70% had combined aortoiliac and superficial femoral disease) undergoing aortobifemoral grafting during a 12-month period. Twenty-three (58%) of the 40 limbs had greater than or equal to 0.1 (m 0.43) increase in ankle-arm index immediately after operation, of which 15 (65%) had a further increase of greater than or equal to 0.1 in late postoperative ankle-arm index. Seventeen (42%) had a decrease, < 0.1 increase, or no change in ankle-arm index immediately after operations, but ten (59%) of these had an ultimate increase of greater than or equal to 0.1 in late postoperative ankle-arm index Thirty-eight (95%) of the extremities were either asymptomatic or greatly improved. These data indicate that 1) secondary distal reconstructive procedures are infrequently necessary after aortobifemoral grafting; 2) significant changes in ankle-arm indexes occur after the immediate postoperative period; 3) the majority of limbs in which the ankle-arm index decreases, is unchanged, or insignificantly increaed early postoperatively will ultimately have a significant rise in ankle-arm index late postoperatively; and 4) immediate postoperative ankle-arm index is not an accurate or reliable predictor of the need for immediate distal reconstructive procedures after aortobifemoral grafting. The authors' current approach towards this problem is to delay secondary distal reconstructive procedures, depending upon patients' symptoms and late hemodynamic results.

Ankle↗
PubMed1980

Measurements of coronary reactive hyperemia with a Doppler probe. Intraoperative guide to hemodynamically significant lesions.

The physiological significance of coronary obstructions of intermediate severity are difficult to assess from the angiogram alone. The hemodynamic significance of clinical coronary stenoses can be readily assessed, however, with a miniaturized Doppler probe developed at The University of Iowa Hospitals and Clinics to measure phasic coronary velocity. No dissection of the coronary vessel is required. The probe is held in place over the coronary vessel with a small suction cup. Reactive hyperemia responses obtained following a 20 second occlusion clearly demonstrate the hemodynamic significance of a coronary stenosis. We have employed this approach in 64 patients with coronary artery disease. In 12 (19%) in whom the degree of stenosis of the vessel was equivocal (diameter narrowing 25% to 70%), the use of the Doppler probe and a 20 second reactive hyperemia curve allowed accurate and immediate assessment of the need for a bypass. Five of these equivocal lesions did not produce any alterations in coronary reserve and, accordingly, the vessels were not bypassed. In seven of them, the reactive hyperemia response was markedly depressed and as a result the vessel in question was bypassed. Thus measurements of coronary reactive hyperemia in vessels with obstruction of intermediate severity can influence the operative plan by assessing the physiological significance of the obstruction.

Adult↗
PubMed1979

Determination of intestinal viability by Doppler ultrasound.

The Doppler ultrasonic flowmeter was used to determine intestinal serosal and mesenteric blood flows in 130 patients who underwent abdominal aortic vascular procedures and in 14 patients who underwent general surgical procedures. Temporary occlusion of the inferior mesenteric artery (IMA) during aortic surgery resulted in the absence or marked diminution of collateral blood flow over the left side of the colon in eight patients. One patient had the flow in the IMA preserved by proper placement of an end-to-side aortofemoral Dacron prosthesis, whereas the other seven patients underwent replantation of the IMA into the Dacron prosthesis. All patients did well postoperatively. In the 14 general surgical patients, intestinal viability and collateral mesenteric blood flows were determined, which demonstrated that the presence of audible arterial blood flow correlated with ultimate bowel viability. We recommend the use of the Doppler ultrasonic flowmeter in abdominal aortic revascularization procedures to determine the need for IMA reconstruction as well as in general surgical procedures where the surgeon desires a more objective assessment of intestinal viability.

Aorta, Abdominal↗
PubMed1979

In vivo comparison of replamineform, Silastic, and bioelectric polyurethane arterial grafts.

The replamineform process allows fabrication of microporous prostheses with control of both pore diameter and structural geometry by means of a variety for biomaterials. Tubular prostheses 3 cm long, 6 mm inside diameter, and 1 mm wall thickness were made of Silastic or Bioelectric Polyurethane (BEP) with use of a template of the echinoderm Heterocentrotus mammillatus. Pore diameter of the prosthesis wall was 18 to 25 mu. Light and scanning-electron microscopy of grafts removed between 1 and 32 weeks demonstrated that organization and endothelialization of neointima were similar for both polymers, being complete by 4 to 8 weeks. However, the character of prosthesis wall ingrowth was strikingly different: the microporous lattice of BEP was completely ingrown early, but was apparently fragmented by continued granulomatous inflammation by 32 weeks, while Silastic generated minimal inflammatory response and slower fibrous tissue and capillary ingrowth. Thus, with Silastic and BEP, similarities in neointima organization appeared independent of distinct differences in wall ingrowth. The replamineform process is a unique means of studying surface healing and wall ingrowth of different biomaterials as microporous vascular prostheses in a controlled fashion.

Arteries↗