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Biomedical subjects

D G Hall

Publications and source records attributed to D G Hall.

At least 73 records · Page 4Linked to original sources
PubMed1984

Pulsed Doppler echocardiographic evaluation of ventricular septal defect patches.

Doppler echocardiography has been shown to have high sensitivity and specificity for noninvasive detection of the flow disturbance of ventricular septal defect. After surgery for ventricular septal defect, one might expect loss of the ventricular septal defect flow disturbance. We used two-dimensional and pulsed Doppler echocardiography to evaluate 30 children undergoing surgery for ventricular septal defect to determine postoperative Doppler findings and the effect of ventricular septal defect patch material on those findings. Twenty-one patients had Dacron patches and nine pericardial patches. Doppler examinations were performed immediately after surgery and at intervals thereafter. The patches were imaged on two-dimensional echocardiograms and the Doppler method was used to evaluate flow at the patches. Doppler echocardiography was also used to estimate volume flow in the aorta and pulmonary artery to estimate postoperative ratio of pulmonary to systemic flow (Qp/Qs). Immediately after surgery 93% of patients had a flow disturbance detected by Doppler echocardiography in the region of the surgically placed patch. On postoperative day 1, 62% of Dacron-patched defects and 66% of pericardial patched defects showed evidence of residual shunting on Doppler examination. By the third postoperative day, this prevalence fell to 23% and 44%, respectively. By 2 weeks after surgery there was evidence of residual shunting in only two patients. In 26 of 30 early postoperative Qp/Qs estimates were under 1.6/1; all but two of these lost the Doppler-detected flow disturbance by 2 weeks after surgery. In three of 30 Qp/Qs estimates exceeded 1.9/1; two of these three required reoperation.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Volume Determination↗
PubMed1982

Severe left main coronary arterial stenosis with right coronary arterial occlusion: results of bypass graft surgery.

A detailed study was made of preoperative, operative and postoperative data from 69 patients with severe (70 percent or greater) luminal narrowing of the left main coronary artery and occlusion of the right coronary artery who underwent bypass surgery from December 1970 through December 1978. Preoperatively, 40.6 percent of patients were in functional class III and 55.1 percent in class IV. Ninety-six percent of those tested had a positive electrocardiographic treadmill test. Coronary bypass grafting was accomplished using standard techniques in all patients. An average of 2.7 grafts/patient were placed. The hospital mortality rate was 4.3 percent, and an additional 4.3 percent died before the end of 1 year. A history of congestive heart failure was a significant predictor (p less than 0.05) of postoperative mortality. An intraaortic balloon pump was not inserted in 64 patients, and our experience suggests that it was a necessary preoperative adjunct. A postoperative treadmill test was negative in 92 percent of those patients tested. Of those surviving 1 year postoperatively, 89 percent were in functional class I and 8 percent in class II. This study demonstrates a surgical mortality rate comparable with that of patients with left main coronary stenosis alone and a significantly better survival rate than that of similar patients treated medically.

Adult↗
PubMed1982

Results of combined left ventricular aneurysmectomy and coronary artery bypass: 1974 to 1980.

Left ventricular aneurysm repair with coronary artery bypass grafting was performed in 104 patients from 1974 through 1980. The patients' mean age was 57 years. Preoperatively, 48 percent were in New York Heart Association functional class III and 31 percent were in class IV. Stenosis of multiple vessels was common, as was a reduced ejection fraction (24 percent had an ejection fraction of less than 30 percent). Thrombus was present in 47 percent of resected aneurysms. Bypass grafting was performed to all graftable coronary vessels. Actuarial survival rates were 89.3 percent at 1 year, 86.1 percent at 2 years, and 74.5 percent (standard error 5.1 percent) at 5 years. One year postoperatively, 86 percent of the surviving patients were in class I, 11 percent class II, 1 percent class III, and 2 percent class IV. Patients who presented with angina alone had an excellent result, with 95 percent hospital survival. Congestive heart failure was an ominous finding, since four of five patients who developed it before discharge died in the hospital, and 38 percent of those who went into heart failure after discharge have died.

Adult↗
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↗
PubMed1980

New treatment for herpes simplex virus type 2 [ultrasound and zinc, urea and tannic acid ointment]. Part II: Female patients.

Clinical treatment of 147 female patients suffering with genital herpes simplex virus were conducted in two phases. The purpose of Phase I was to note the efficacy of treatment with ultrasound and Herpigon ointment (zinc, urea, and tannic acid) in relieving pain and shortening the length of time involved in healing. Results indicated that the combined treatment significantly reduced pain and length of healing period. Phase II involved a 2-year follow-up of patients with primary and recurrent infection. Results indicated that the combined treatment significantly reduced recurrent infection in all patients treated.

Adult↗
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

Cardiac surgery under age two years. A review.

To assess the current status and risks of both open and closed cardiac procedures for congenital heart disease in patients under the age of 2 years, we reviewed all cardiac catheterizations and cardiac operations done from January, 1974, through December, 1977, at The Children's Orthopedic Hospital and Medical Center in Seattle, Washington. In this interval 370 patients under 2 years of age were catheterized. Eighty open procedures were performed in patients under 2 years of age, with seven hospital deaths. One hundred twenty-four closed heart procedures were performed on children under the age of 2 years, with eight deaths, for a hospital mortality rate of 6.5 percent. This review of consecutive cases over a 4 year period suggests that the judicious application of palliation or open repair using current techniques can lead to an overall mortality rate of between 6 and 7 percent for both open and closed heart procedures in children under 2 years of age. Since all deaths except one in the open-heart group occurred in patients with the most complex multiple defects, it seems reasonable to suggest that improved intraoperative and postoperative techniques have lowered the time for repair of straightforward congenital heart defects to under 2 years of age.

Age Factors↗
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

Use of intraoperative esophageal manometrics in surgical treatment of gastroesophageal reflux in pediatric patients.

Intraoperative lower esophageal sphincter (LES) pressures and lenghts were measured in 10 pediatric patients requiring surgery for compications of gastroesophageal reflux. LES pressure changed significantly pre- and post-Nissen fundoplication (9.8 +/- 1.51 mm Hg vs. 32.8 +/- 2.68 mm Hg, p less than 0.001). LES length also showed a significant change (1.3 +/- 0.13 cm vs. 2.8 +/- 0.26 cm, p less than 0.001). One week postoperatively LES pressures were significantly greater than preoperative values (26.4 +/- 1.74 mm Hg vs. 15.6 +/- 2.64 mm Hg, p less than 0.01). Eight of 10 patients have been evaluated 6 mo post fundoplication. None has gastroesophageal reflux by acid reflux testing or water siphon barium esophagram. None of the 10 patients has had gas bloat syndrome during the follow-up period.

Adolescent↗
PubMed1978

The care of vascular endothelium in pediatric surgery.

The influence of manipulating blood vessels by clamping, drying, stretching and surgical anastomotic technique on the subsequent integrity of blood vessel endothelium has been studied in the dog. Thrombogenesis at the vessel surface was found in all specimens where loss of endothelium had exposed subendothelial tissues. Whether thrombotic occlusion of the vessel followed depended upon several local factors including the amount of surface area damaged and volume of blood flow in the vessel. All modes of vessel manipulation studied led to significant endothelial damage. To prevent this damage in the clinical setting all possible methods to avoid the exposure of subendothelial tissues should be used. Endothelial integrity is the cornerstone to success in handling blood vessels and avoiding thrombogenesis. This study suggests that clamping of blood vessels should always be done with a minimum of force, only preventing blood flow, and not crushing the vessel wall. Endothelial surfaces should never be allowed to become dry. Stretching should be avoided as it can lead to thrombosis within intact blood vessels when the endothelium is disrupted. Suture anastomotic techniques should be used which minimize endothelial trauma and thus avoid subendothelial tissue reactions which in turn may jeopardize long-term patency and growth at anastomotic sites. In pediatric cases where growth is anticipated interrupted suture technique should be used. This study suggests that many techniques currently used in vascular surgery may be compromising to short and long-term blood vessel patency.

Animals↗
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↗
PubMed1977

Ultrasound as a new method of male contraception.

Twenty male cats were treated once or twice with 1 watt/sq cm of ultrasound for 10 minutes. Each of 24 male dogs received one to three treatments with 1 watt/sq cm for 10 minutes. Another six dogs were treated with 2 watts/sq cm for 15 minutes. Four Cebus apella monkeys were treated with the same dosage as that used for the cats and dogs. A dosage of 1 watt/sq cm for 10 minutes was also applied to four human patients without the use of anesthetics, and no pain or side effects were noted. In all treated animals as well as in human patients the results indicate that ultrasound significantly suppresses spermatogenesis according to the dosage and frequency of treatment, without any effect on Leydig cells or blood testosterone levels.

Animals↗
PubMed1976

Beneficial metabolic effects of methylprednisolone sodium succinate in acute myocardial ischemia.

The metabolic and hemodynamic effects of methylprednisolone sodium succinate (40 mg/kg body weight) after acute myocardial ischemia were determined in 24 heparinized mongrel dogs. Myocardial ischemia was produced by ligation of the left anterior descending coronary artery. Catheters in the coronary sinus and the vein draining the left anterior descending coronary arterial area were used to collect blood samples from nonischemic and ischemic myocardium. Lactate, pyruvate, glucose, free fatty acids and oxygen were measured in arterial and venous blood from ischemic and nonischemic areas before and 3, 30 and 60 minutes after myocardial ischemia in animals with (Group II) and without (Group I) steroid treatment. In both Groups I and II glucose, lactate, free fatty acids, oxygen and coronary blood flow in nonischemic areas were not significantly changed, whereas glucose uptake in ischemic areas was significantly increased with myocardial ischemia and remained elevated. In Group I lactate uptake in ischemic areas became negative after coronary arterial ligation and remained so; in Group II, it increased after 30 (70%) and 60 (111%) minutes. Free fatty acid uptake in ischemic areas was reduced after myocardial ischemia in Group I, but in Group II it increased after 30 (224%) and 60 minutes (173%), and there was a concomitant increase in oxygen uptake. Pyruvate uptake in nonischemic areas decreased after 60 minutes in Group I, whereas it was reduced after 30 (68%) and 60 minutes (513%) in Group II. The changes were similar in ischemic myocardium. There were no significant changes in hemodynamic indexes. Coronary blood flow in ischemic areas decreased in Group I after myocardial ischemia and further after 30 and 60 minutes, but in Group II it increased after 30 (82%) and 60 minutes (53%). The data indicate that administration of methylprednisolone results in improved collateral blood flow into the infarcted area and a significantly improved metabolic response of ischemic myocardium. The glucocorticoid may also have a direct benefical effect on carbohydrate metabolism and cause the increased pyruvate neccesary to maintain the generation of energy-producing substrates. The results also suggest that methylprednisolone increases cell survival time and results in greater salvage of ischemic myocardium.

Acute Disease↗