Biomedical subjects

G M Lemole

Publications and source records attributed to G M Lemole.

At least 37 records · Page 2Linked to original sources

PubMed1991

Prevention of radioactive indicator and viral particle transmission with an ointment barrier.

OBJECTIVE: To determine the efficacy of a lanolin-based gel in preventing radioactive particle and viral penetration. DESIGN: Paired, stacked filter discs were held in a stainless steel support, and the gel was applied manually to the upper surface of the upper filter. Indicator solution containing either radioactive viral particles (3H-labeled simian virus 40 or 3H-labeled woodchuck hepatitis virus) or 20 microliters or 100 microliters of 32P-labeled radioactive compounds of much lower molecular weight then were applied to the upper filter. The filter discs were separated after 30 minutes, and the lower disc was examined for radioactivity in a liquid scintillation counter. RESULTS: Transmission of radioactive particles was statistically significantly reduced by the application of the ointment on the upper filter (from 6.7 +/- 0.1 x 10(5) counts per minute [cpm] to 88 +/- 38 cpm). Transmission of both labeled viral particles also was reduced to a similar degree. CONCLUSIONS: Application of protective ointment to the filters significantly reduces transmission of radioactive viral particles and smaller radioactive compounds through filter discs. Use of this ointment may offer similar mechanical protection against the transmission of viruses between patient and healthcare provider.

Equipment Contamination↗

PubMed1991

Total left main coronary artery occlusion after aortic aneurysm repair and valve replacement.

A 38-year-old woman with complete occlusion of the left main coronary artery secondary to cannulation during aortic valve replacement is presented. The clinical course was characterized by progressive left ventricular dysfunction and congestive heart failure. Recognition of this potential problem when it occurs is important as to institute therapeutic measures which may interrupt a patient's progressive clinical deterioration.

Adult↗

PubMed1990

Sutureless ring graft replacement of ascending aorta and aortic arch.

Complications after aortic replacement that result from prolonged graft insertion time and technical difficulties with suturing through friable, diseased aortic tissue can be addressed with use of the sutureless intraluminal ring graft. Between 1978 and 1989, we replaced the ascending aorta or aortic arch with this device in 49 patients. At no time were we unable to use a sutureless graft during a procedure. Twenty-eight cases of aneurysmal disease and 21 cases of acute or chronic dissection were treated. Twenty-six patients required replacement of the aortic valve, with annuloartic ectasia being the most common indication (71%). Ten patients underwent concomitant coronary artery bypass grafting. The operative mortality rate for ascending aortic aneurysm repairs was 4%, and that for dissections was 18%. Five of 8 patients requiring aortic arch replacement survived. Most patients were studied angiographically before discharge. No complications were related to anastomotic hemorrhage, pseudoaneurysm formation, graft migration, or thromboemboli. Individual cases of phrenic nerve palsy, acute tubular necrosis, and transient ischemic attack, all of which resolved completely, were identified. The actuarial 5-year survival rate is 64%. We conclude that modification of the sutureless intraluminal ring graft to suit the pathology encountered at operation allows the quickest repair with the least chance of anastomotic complication.

Adolescent↗

PubMed1990

Aortic valve repair for aortic stenosis in adults.

The stenotic aortic valve was surgically repaired in 48 adults, 21 women and 27 men, aged 38 to 83 years. Five had congenital aortic stenosis (AS), with a mean aortic valve gradient and area of 58 +/- 23 mm Hg (standard deviation) and 0.54 +/- 0.13 cm2, respectively; 32 had senile AS with a mean aortic valve gradient and area of 43 +/- 20 mm Hg and 0.98 +/- 0.41 cm2; and 11 had rheumatic AS with a mean aortic valve gradient and area of 59 +/- 24 mm Hg and 0.47 +/- 0.15 cm2. Only 6 patients underwent isolated aortic valvoplasty, 11 underwent concomitant mitral valve procedure, and 34 underwent concomitant coronary revascularization. Repair consisted of decalcification in 33 patients and decalcification as well as commissurotomy in 15 patients. There were three hospital deaths, none related to the aortic valve. Only 2 patients (both rheumatic) did not improve clinically. During follow-up (mean, 64 +/- 41 months) aortic valve restenosis developed in 24% (10 patients, 3/5 congenital, 4/11 rheumatic, and 3/32 senile) at a mean of 64 +/- 28 months. Postoperative Doppler echocardiographic assessment of 21 patients with senile AS at 1.1 +/- 2.7 and 18.1 +/- 1.4 months showed significantly lower aortic valve gradient and improved area in comparison with preoperative values. At 36 +/- 2.7 months, aortic valve gradient and area were not significantly different than preoperative values, and at 58.5 +/- 2.6 months aortic valve gradient was 1.41 (p = 0.07) times the preoperative value. At 7 years, actuarial freedom from aortic valve-related symptoms of the patients with senile AS was 87%. We conclude that in select patients aortic valve repair results in excellent relief of AS. Late restenosis is expected and more likely to occur in the valves with congenital and rheumatic disease than in those with senile disease.

Adult↗

PubMed1990

Determinants of pulmonary function in patients undergoing coronary bypass operations.

Pulmonary function testing was conducted consecutively in 29 healthy men (age range, 42 to 71 years) undergoing elective coronary artery bypass grafting. Lung volumes, expiratory flow rates, diffusing capacity, and blood gases were determined before operation, at discharge (8.7 +/- 1.9 days), and at 3 months postoperatively. In addition, peak expiratory flow rate was measured immediately after extubation (21.4 +/- 2.7 hours). Fifteen patients had smoked within the past year, but none had a history of pulmonary impairment. Twenty-two patients had internal mammary artery (IMA) dissection. Operation and recovery were uneventful in all cases. After extubation, peak expiratory flow rate was decreased by 65%. At discharge, lung volumes were decreased by 19% to 33% below preoperative values and expiratory flow rates were decreased by 33% to 37% below preoperative values. Some minor changes were detected at 3 months. Further analysis of these changes according to smoking history, age, preoperative weight, dissection of IMA, and aortic cross-clamp time showed that only IMA dissection affected the postextubation changes in peak expiratory flow rate (p less than 0.0001), whereas the decreases in functional residual capacity and expiratory reserve volume at discharge were affected by IMA dissection (p less than 0.05) and age (p = 0.01). Thus, median sternotomy is associated with severe but short-term pulmonary dysfunction; IMA dissection has a significant adverse effect on these changes.

Age Factors↗

PubMed1990

Aortic replacement with sutureless intraluminal grafts.

To avoid the anastomotic complications and long cross-clamp times associated with standard suture repair of aortic lesions, we have implanted sutureless intraluminal grafts in 122 patients since 1976. Forty-nine patients had disorders of the ascending aorta, aortic arch, or both: their operative mortality was 14% (7 patients), and the group's 5-year actuarial survival rate has been 64%. There have been no instances of graft dislodgment, graft infection, aortic bleeding, or pseudoaneurysm formation. Forty-two patients had disorders of the descending aorta and thoracoabdominal aorta: their early mortality was 10% (4 patients), and the group's 5-year actuarial survival rate has been 56%. There was 1 early instance of graft dislodgment, but no pseudoaneurysm formation, graft erosion, aortic bleeding, intravascular hemolysis, or permanent deficits in neurologic, renal, or vascular function. Thirty-one patients had the sutureless intraluminal graft implanted in the abdominal aortic position: their early mortality was 6% (2 patients), and the 5-year actuarial survival rate for this group has been 79%. There were no instances of renal failure, ischemic complication, postoperative paraplegia, pseudoaneurysm, or anastomotic true aneurysm. Our recent efforts have been directed toward developing an adjustable spool that can adapt to the widest aorta or the narrowest aortic arch vessel; but in the meanwhile, the present sutureless graft yields shorter cross-clamp times, fewer intraoperative complications, and both early and late results as satisfactory as those afforded by traditional methods of aortic repair.

Journal Article↗

PubMed1990

Effects of a 2.15-micron laser on human atherosclerotic xenografts in vivo.

The thulium-holmium-chromium:yttrium-aluminum-garnet (THC:YAG) laser has a tissue effect similar to that of the CO2 laser, with the advantage of transmissibility through flexible fibers. The authors used a human-rabbit xenograft model to evaluate the thrombotic and healing responses of atherosclerotic vessels subjected to laser energy. Occluded atherosclerotic human coronary artery segments were recanalized in vitro by use of the THC:YAG laser. Destruction of plaque by the laser was achieved with minimal collateral thermal damage. These vascular segments were then transplanted into the rabbit abdominal aorta. The authors observed that the luminal surface of the lased vessels was more thrombogenic than that of the nonlased control vessels. However, occlusion of the lased vessels did not occur. Repair of laser-treated tissue progressed until a mature, nonthrombogenic fibrin-platelet aggregate was adherent to the luminal wall. Overall, the lased vessels behaved in a fashion similar to the nonlased control vessels. On the basis of these results, the authors believe that the THC:YAG laser may have use in human angioplasty.

Angioplasty, Laser↗

PubMed1990

Aortic replacement with composite grafts created with a sutureless intraluminal ringed prosthesis.

From 1980 to 1988, 30 patients from a total population of 123 recipients of sutureless grafts (24%) have required aortic reconstruction with a composite ringed graft. Replacement of the ascending aorta was required in 12 patients, of the aortic arch in six patients, of the descending aorta in two patients, of the thoracoabdominal aorta in two patients, and of the abdominal aorta in eight patients. Eight patients (27%) needed an emergency operation at the time of admission. No patients had permanent neurologic or renal deficits. There was no evidence of pseudoaneurysm formation, graft erosion, graft migration, or aortic bleeding in the postoperative period. Two operative deaths (7%) occurred, both in patients undergoing arch reconstruction. Composite grafts can be created that vary in length and shape, incorporate different graft materials, and accommodate the aorta and its branches. The ability to modify the sutureless prosthesis to suit the disease encountered at operation allows the quickest repair with the least chance of anastomotic complication.

Adult↗

PubMed1990

A flexible sutureless intraluminal graft that becomes rigid after placement in the aorta.

A new sutureless intraluminal graft has been developed with a ring made of a coiled, overlapping, stainless steel spring with ratchets in one overlapping end. This graft is flexible during insertion but becomes rigid after proper intraaortic placement as the spool is dilated and the ratchest lock into position. The new graft was implanted in 10 dogs and was evaluated histologically and angiographically at various intervals. No ring dislodgment, aortic rupture, stenosis, or aneurysmal dilation was observed. The flexible component of this graft allows it to be introduced and secured in place easily and provides a technical advantage compared with the clinically used rigid intraluminal graft.

Animals↗

PubMed1990

Occlusion of aortocoronary vein grafts in association with bovine pericardium.

A case is reported in which the use of heterologous bovine pericardium in coronary revascularization was associated with firm adhesions and complete occlusion of all vein grafts after eight months. Heterologous pericardial substitutes may have a deleterious effect on vein grafts and may not avert epicardial-pericardial adhesions.

Adult↗

PubMed1990

Twelve-year experience with intraluminal sutureless ringed graft replacement of the descending thoracic and thoracoabdominal aorta.

Use of the intraluminal sutureless ringed prosthesis can reduce graft insertion time and avoid difficulties inherent in suturing to friable, diseased aortic tissue. Since 1976 this device has been inserted into the descending thoracic or thoracoabdominal aorta in 42 procedures for aortic dissection and for aneurysmal disease. The operative mortality rate for descending thoracic aortic dissection repair was 14% and that for descending thoracic aortic aneurysm repair was 8%, with an overall mortality rate of 10%. All three of the patients undergoing thoracoabdominal aortic replacement survived. The mean cross-clamp time for sutureless tube graft insertion was 9 minutes. The average blood replacement was 2.4 units/patient. No patient suffered serious neurologic or renal impairment. A single nonfatal case of graft dislodgement occurred after placement. No evidence of hemolysis, pseudoaneurysm formation, graft erosion, graft migration, or anastomotic bleeding was present in any of the remaining patients. Modification of the sutureless intraluminal device to suit the pathologic condition encountered at operation allows rapid repair with a low incidence of anastomotic complication.

Adolescent↗

PubMed1989

Replacement of the abdominal aorta with a sutureless intraluminal ringed prosthesis.

To evaluate our experience with sutureless intraluminal ringed grafts in the abdominal aorta, we reviewed all patients who were managed with this device from 1980 to 1987. Thirty-one patients were identified with a mean follow-up time of 41 months. Three patients had suprarenal aneurysms and four had ruptured abdominal aneurysms. Average tube graft insertion time was 17 minutes and required 0.9 units of transfused blood. There were two postoperative deaths (6 percent), both secondary to myocardial infarction. None of the patients with ruptured or suprarenal aneurysms died. No patients had permanent renal or neurologic deficits, and no instances of postoperative bleeding, wound infection, pseudoaneurysm formation, or graft migration were encountered. The sutureless intraluminal graft can be implanted easily and quickly and is safe for use in the abdominal aorta. It is particularly helpful in the management of suprarenal or ruptured abdominal aneurysms, in which speed is important, and in effecting technically difficult anastomoses to friable aortic tissue.

Adult↗

PubMed1989

Replacement of the descending thoracic aorta with intraluminal ring graft.

Renal failure and paraplegia are major complications of operations on the descending thoracic aorta. To minimize cross-clamp time and reduce the incidence of such complications, we have used an intraluminal ring graft to reestablish aortic continuity in patients with descending thoracic aortic lesions. From March 1978 to December 1986, we used this technique alone in 28 patients. There were 4 patients with traumatic aortic disruptions, 4 with dissections, 4 with expanding aneurysms, 2 with ruptured aneurysms, 1 with Marfan's syndrome, and 13 with atherosclerotic aneurysms that were repaired electively. The cross-clamp times ranged from 4 to 28 minutes. There were three early postoperative deaths (within 30 days) and one late postoperative death in the follow-up period (mean, 28.2 months). Ring dislodgement occurred only once, in the first patient in this series. There were no instances of postoperative renal failure or paraplegia. We conclude that the use of an intraluminal ring graft greatly reduces the aortic cross-clamp time and is a safe and effective technique.

Adolescent↗

PubMed1989

A ten-year experience with bacterial aortitis.

Twenty-one patients with bacterial aortitis were treated in four institutions over a 10-year period. Clues to the diagnosis were a pulsatile mass; fever; positive blood culture; CT scan revealing aortic nodularity, an aneurysm of irregular configuration, or air in the aortic wall; and angiography revealing a lobulated aneurysm. The most commonly identified organisms were Salmonella and Staphylococcus. Excision with in situ repair was performed in nine patients; 11 patients underwent extraanatomic bypass grafting with aortic ligation. In situ graft repair was performed when the infected aorta could be removed entirely or when the thoracic or suprarenal aorta was involved. Axillofemoral bypass grafting was used when infection was extensive. There were eight disease-related deaths. No graft infections were encountered in patients who survived.

Aged↗

PubMed1989

Prophylactic treatment of postperfusion bleeding using EACA.

To determine the effects of prophylactic treatment with EACA for blood loss after cardipulmonary bypass surgery, 350 consecutive patients undergoing open-heart surgery were studied. One hundred seventy patients received an initial dose of 5 g of EACA prior to skin incision, followed by intravenous administration of 1 g/h for the next 6 to 8 h. The control group received saline solution in the same fashion. The EACA-treated group had decreased chest tube blood loss 24 h postoperatively. In addition, EACA-treated patients had fewer myocardial infarctions, cerebrovascular accidents or reoperations for bleeding. Treated patients needed fewer units of blood transfusions than the nontreated group. There was no incidence of hyperthrombotic state or other side effects in the EACA-treated group. We concluded that prophylactic treatment with EACA for open-heart surgery requiring extracorporeal circulation may reduce the total blood loss and the number of blood transfusions in a safe and tolerable manner.

Aminocaproates↗

PubMed1989

Ebstein's anomaly: unusual presentation and surgical repair.

Ebstein's anomaly is the most significant congenital anomaly involving the tricuspid valve. This lesion may present in a simple form or may be complicated by other lesions. Patients with this anomaly may vary from mildly symptomatic to severely debilitated. The role of surgical treatment is not uniformly agreed upon, and the optimal procedure for correction or palliation is not clearly defined. Because of the wide spectrum of morphologic abnormalities which may be present in Ebstein's anomaly, no one particular operation may always be satisfactory. We and other groups continue to search for optimal procedures and feel strongly that individualization must be carried out to optimize the result in each patient. We encountered a patient with Ebstein's anomaly in an almost atretic tricuspid valve. In addition, there was severe right ventricular outflow tract obstruction and pulmonary valve stenosis. In this patient the "Fontan Principle" was successfully applied in his management.

Child↗

PubMed1988

Adjunct endarterectomy of the left anterior descending coronary artery.

During a three-year period, complete revascularization of diffusely diseased left anterior descending (LAD) coronary arteries was accomplished by extensive endarterectomy in conjunction with bypass grafting in 37 patients in whom conventional bypass was not feasible. This group constituted 7.0% of all patients undergoing nonemergency coronary revascularization during this period. The left internal mammary artery was used to bypass the endarterectomized LAD artery in 22 patients. There was 1 (2.7%) operative death and 1 perioperative myocardial infarction. At follow-up, which was 100% with a mean of 41.4 months, all endarterectomy patients were in New York Heart Association Functional Class I or II. Twenty-four endarterectomy patients underwent first-pass radionuclide angiographic stress testing 20 months after operation. Twenty patients (83%) had excellent postoperative exercise tolerance, achieving 5 to 7 mets on treadmill testing. Left ventricular functional reserve was preserved, as evidenced by an increase of global ejection fraction from 48 +/- 15% at rest to 59 +/- 18% (p less than 0.005) with exercise. A similar increase was measured in the proximal and distal anterior wall segmental ejection fractions. No difference in response to exercise was found between the internal mammary artery and the vein graft groups. Thus, complete revascularization of the diffusely diseased LAD artery can be accomplished by adjunct endarterectomy without added morbidity or mortality and with excellent functional results.

Adult↗

PubMed1988

High frequency, high volume ventilation for right ventricular assist.

During ventilation, the lungs may serve as accessory pumps for forward blood flow. We have noted significant hemodynamic improvement in several patients during short periods of vigorous hand ventilation with the Ambu bag and tried to reproduce the hemodynamic improvement in the management of four patients with profound low cardiac output syndrome secondary to right ventricular (RV) failure following open heart surgery. High frequency, high volume (HFHV) ventilation resulted in improved hemodynamics in these patients, as evidenced by pulsatile pulmonary blood flow and increased cardiac output. Right-sided stroke work was present and there was a fall in mean central venous pressure (CVP) and rise in mean pulmonary artery pressure (PAP).

Assisted Circulation↗