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Biomedical subjects

E Kieffer

Publications and source records attributed to E Kieffer.

At least 19 recordsLinked to original sources
PubMed1996

Arteries from human beings are less infectible by Staphylococcus aureus than polytetrafluoroethylene in an aortic dog model.

PURPOSE: Treatment of aortoiliac prosthetic graft infections includes the removal of the infected material and repeat revascularization if necessary. The risk of infection of the graft material used for the repeat revascularization has been the drawback of its use in situ except with autografts. Good results were obtained in this setting by use of in situ arterial allografts. The purpose of our study was to compare in vivo the infectibility of arteries used as allografts to the infectibility of commercially available prostheses. METHODS: Twelve dogs underwent thoracoabdominal aortic bypass with use of either an artery from a human being (n=6) or an expanded polytetrafluoroethylene (ePTFE) graft (n=6). One month later, bacteremia was produced with Staphylococcus aureus. One week after bacterial challenge, the animals were killed to recover the grafts. Each graft then underwent bacterial study. RESULTS: None of the arterial grafts grew bacteria, whereas four of the six ePTFE grafts (p < 0.05) did. In addition, none of the fragments of the arterial grafts grew bacteria, whereas 24 of the 60 ePTFE fragments (p < 0.01) did. CONCLUSION: Nonautologous arteries are less infectible than ePTFE in vivo. This decreased infectibility makes the arterial allograft an appealing material when revascularization must be performed in a contaminated field.

Animals↗
PubMed1996

Pregnancy outcomes of US-born and foreign-born Japanese Americans.

OBJECTIVES: This study investigated the birth outcomes of Japanese Americans, focusing on the role of the mother's place of birth. METHODS: Single live births to US-resident Japanese American mothers (n = 37,941) were selected from the 1983 through 1987 US linked live birth-infant death files. RESULTS: US-born mothers were more likely than foreign-born mothers to be less than 18 years old and not married, to start prenatal care early, and to more adequately use prenatal care. Infants of foreign-born Japanese Americans had a slightly lower risk of low birthweight.No significant differences were found between nativity groups for very low birthweight or neonatal, postneonatal, and infant mortality. The mortality rates of infants of US-born (6.2) and foreign-born (5.4) Japanese American women were below the US Year 2000 objective but still exceeded Japan's 1990 rate (4.6). However, low-birthweight percentages of the US-born group (5.7%) and the foreign-born group (5.0%) were similar to that of Japan (5.5%). CONCLUSIONS: The infants of foreign-born Japanese-American women exhibited modestly better low-birthweight percentages than those of US-born Japanese Americans. This finding supports theories of the healthy immigrant.

Adolescent↗
PubMed1995

Carotid eversion endarterectomy: short- and long-term results.

From January 1979 to December 1993, of 2723 carotid revascularizations performed on our service, 168 (6.2%) were isolated carotid eversion endarterectomies (CEEs) for atherosclerotic occlusive disease. Since 10 of these procedures were bilateral, there were 158 patients total (88 men and 70 women). Twenty-six (16.5%) had diabetes, 54 (34.2%) had coronary disease, and 107 (67.7%) had hypertension. The mean age was 68.9 +/- 8.9 years (range 38 and 85 years). Preoperative ischemic symptoms were hemispheric in 93 (55.4%) patients, retinal in 31 (18.4%), and vertebrobasilar in 37 (22%). They consisted of one or more strokes in 44 (26.2%) patients and one or more transient ischemic attacks in 99 (58.9%); 25 (14.9%) patients were asymptomatic. The operated lesion contained atherosclerotic stenotic plaque in all cases. The lesion was tightly stenotic (> 75%) and hemodynamically significant in 93 (55.4%) cases and irregular or ulcerated in all others. In 86 (51.2%) patients a coil or kink of the distal internal carotid artery was also present. The contralateral carotid artery was totally occluded in eight (4.7%) patients and tightly stenotic in seven (4.2%). All patients were operated on under deep general anesthesia; they were given systemic heparin and normal blood pressure was maintained. After freeing and cross-clamping of the carotid bifurcation, the end of the common carotid artery or the ostium of the internal carotid artery was sectioned. The section allowed a deep-plane endarterectomy through eversion and excellent control over the endarterectomized surface and its extremities. Since January 1989 completion arteriography has been routinely performed after CEE.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Atherosclerotic innominate artery occlusive disease: early and long-term results of surgical reconstruction.

PURPOSE: Few articles have dealt specifically with surgical management of innominate artery (IA) atherosclerotic occlusive disease. We herein present our early and long-term results in a large series of patients. METHODS: During a 20-year period (1974 to 1993) we operated on 148 patients with IA atherosclerotic occlusive disease. The mean age was 55.8 +/- 9.4 years. Approach was through a median sternotomy in 135 (91%) patients. Endarterectomy was performed in 32 (22%) patients, whereas 116 (78%) patients underwent bypass. RESULTS: Eight (5.4%) patients died in the perioperative period (four of heart-related causes, two of hemorrhage, one each of pulmonary infection and multiorgan failure). There were five (3.4%) perioperative strokes (three ipsilateral, two contralateral) and three (2.0%) ipsilateral perioperative transient ischemic attacks. Ten (7%) patients were lost to follow-up. Mean follow-up was 77 (2 to 193) months. Thirty-three (24%) patients were monitored 10 or more years. There were 45 (35%) late deaths (19 from cardiovascular-related causes, 15 from cancer, 7 from other known causes, and 4 from unknown causes). Although 11 (8.5%) patients had late neurologic events, only one late stroke occurred in the contralateral hemisphere and no ipsilateral late strokes occurred. Sixteen (11%) patients had late myocardial infarctions, nine of which were lethal. Life-table analysis and perioperative events were used to calculate the probability of survival, which was 77.5% +/- 9.5% and 51.9% +/- 20.8% at 5 and 10 years, respectively, with a 4.4% annual mortality rate. The overall probability of freedom from any neurologic/ocular event was 88.8% +/- 6.2% and 80.4% +/- 11.9% at 5 and 10 years, respectively, with a 1.6% annual occurrence rate. The probability of freedom from ipsilateral neurologic/ocular event was 92.7% +/- 4.8% and 84.0% +/- 11.2% at 5 and 10 years, respectively, with a 1.4% annual occurrence rate. The probability of freedom from ipsilateral stroke was 98.6% +/- 1.9% at 5 and 10 years. The primary patency rate was 98.4% +/- 2.1% and 96.3% +/- 4.7% at 5 and 10 years, respectively. The probability of freedom from reoperation was 95.6% +/- 3.9% and 93.5% +/- 5.9% at 5 and 10 years, respectively. CONCLUSIONS: Surgical reconstruction of IA atherosclerotic occlusive disease yields acceptable rates of perioperative complications and late mortality and excellent long-term patency and freedom from neurologic events and reoperation.

Adult↗
PubMed1995

[Effects of platelet-rich plasma on hemostasis and transfusion requirement in vascular surgery].

OBJECTIVE: To assess the effect of intraoperative autologous platelet-rich plasma (PRP) transfusion on haemostasis, blood loss and blood requirements during vascular surgery. STUDY DESIGN: Randomized clinical trial. PATIENTS: Twenty patients undergoing elective abdominal infrarenal aortic aneurysmectomy, using autologous transfusion techniques (predonation programme and/or preoperative normovolaemic haemodilution and/or intraoperative use of a cell-saver), were randomly allocated either into the PRP group (n = 10) or the Control group (n = 10). METHOD: In patients of PRP group, 10 mL.kg-1 of PRP were obtained over 40 to 50 min, prior to induction of anaesthesia, and compensated simultaneously with an equivalent amount of hydroxyethyl starch. Each PRP unit was transfused to its donor after aortic declamping. Blood samples were obtained before induction, before incision, at wound closing and at the end of PRP unit transfusion for determination of biological variables. RESULTS: The PRP units transfused in the patients of PRP group contained 755 +/- 117 mL of plasma with a platelet count of 62 +/- 31 G.L-1. The intra and postoperative blood losses were similar in both groups (1622 +/- 758 and 233 +/- 322 mL respectively in PRP group vs 1890 +/- 1331 and 291 +/- 303 mL respectively in Control group). In both groups, three patients required an additional transfusion of homologous blood. The results of biological tests (haematocrit, platelet and white cell counts, prothrombin time, aPTT, thrombin time, fibrinogen, D-dimers, proteins, calcium) were also similar between groups at the various times of sampling. The reinfusion of the PRP unit did not increase the platelet count. CONCLUSIONS: This study demonstrates that intraoperative infusion of autologous PRP does not decrease blood loss and homologous transfusion requirements in patients undergoing elective abdominal infrarenal aortic aneurysmectomy. This result can be related to the relatively moderate enrichment in platelets obtained with the centrifugation speed used in this study.

Aortic Aneurysm, Abdominal↗
PubMed1995

Arterial lesions in Behçet's disease. A study in 25 patients.

OBJECTIVE: To identify the prognostic indicators of patients with Behçet's disease complicated with arterial lesions. METHODS: Retrospective chart analysis of 25 consecutive patients with Behçet's disease and angiographically proven arterial lesions. RESULTS: Occlusive lesions were present in 7 patients, aneurysms in 3, and both occlusive and aneurysmal lesions in 15. High dose corticosteroids were not effective in isolated occlusive lesions and probably contributed to one fatal infection. Death was related to aneurysms in 5 patients. Twenty-seven vascular surgical procedures were performed in 15 patients. Arterial lesions recurred in all patients who did not received postoperative corticosteroids. Within a 2 yr period after operation, the rate of therapy failure was lower in the group of patients treated with a postoperative combination of corticosteroids and immunosuppressive drugs, compared to the group treated with corticosteroids alone. In patients treated for lower limb arterial lesions, the rate of relapse was similar whether venous autologous or prosthetic grafts were used. Graft thrombosis occurred in 3/7 patients given anticoagulants and in 3/4 patients with no antiaggregant or anticoagulant therapy. CONCLUSION: Aneurysms have a worse prognosis than occlusive lesions. High dose corticosteroids should not be systematically prescribed for isolated occlusive lesions. Surgery, when feasible, is indicated for aneurysms because they entail a high risk of rupture. Postoperative corticosteroids are necessary to prevent arterial relapse. A combination of corticosteroids and immunosuppressive therapy is more effective than corticosteroids alone. After bypass for lower limb arterial lesions, anticoagulation is warranted to prevent graft thrombosis.

Abdomen↗
PubMed1994

Dipyridamole-thallium scintigraphy and gated radionuclide angiography to assess cardiac risk before abdominal aortic surgery.

BACKGROUND: Because many patients with atherosclerotic disease of the abdominal aorta also have coronary artery disease, assessment of cardiac risk before abdominal aortic surgery has received much attention. Our prospective study was designed to identify predictors of cardiac risk in consecutive patients evaluated preoperatively with dipyridamole-thallium single-photon-emission computed tomography (SPECT) to assess myocardial perfusion and radionuclide angiography to measure left ventricular ejection fraction. METHODS: Clinical and scintigraphic data were collected prospectively during hospitalization in 457 consecutive patients undergoing elective abdominal aortic surgery. Adverse cardiac outcomes were predicted with multivariate analyses. RESULTS: Eighty-six patients (19 percent) had one or more of the following postoperative complications: prolonged myocardial ischemia (61 patients), myocardial infarction (22), congestive heart failure (20), and severe ventricular tachyarrhythmia (2). Twenty patients died postoperatively (4.4 percent), half of them from cardiac causes. Information about myocardial perfusion obtained from dipyridamole-thallium SPECT did not accurately predict adverse cardiac outcomes. The best correlates of cardiac complications were definite clinical evidence of coronary artery disease (odds ratio, 2.6; 95 percent confidence interval, 1.6 to 4.3) and age greater than 65 years (odds ratio, 2.3; 95 percent confidence interval, 1.4 to 3.6). Measurement of the ejection fraction was useful only in the prediction of left ventricular failure. Age greater than 65 years was the only predictor of death (odds ratio, 26.4; 95 percent confidence interval, 3.5 to 200.0). CONCLUSIONS: The presence of definite clinical evidence of coronary artery disease and older age were the most important preoperative predictors of an adverse cardiac outcome after abdominal aortic surgery. These results suggest that the routine use of dipyridamole-thallium SPECT and radionuclide angiography for screening before abdominal aortic surgery may not be justified.

Aged↗
PubMed1994

Aprotinin to decrease bleeding and intraoperative blood transfusion requirements during descending thoracic and thoracoabdominal aortic aneurysmectomy using cardiopulmonary bypass.

The purpose of this retrospective study was to assess the efficacy of aprotinin, an antifibrinolytic agent, in reducing bleeding and blood transfusion requirements in patients undergoing descending thoracic or thoracoabdominal aortic aneurysmectomy using cardiopulmonary bypass (CPB). Sixty-nine consecutive patients underwent thoracic or thoracoabdominal aneurysmectomy using CPB in a 2-year period. None of the 29 patients operated on in 1990 (group 1) received aprotinin, whereas all 40 patients operated on in 1991 (group 2) were placed on a high-dose regimen of aprotinin. There were no significant differences between the two groups. Administration of aprotinin was associated with a decrease in CPB time (p = 0.02), surgical duration (p = 0.05) and intraoperative blood loss (p = 0.008) as well as a reduction in intraoperative packed red cells (p = 0.01), Cell-Saver units (p = 0.05), fresh-frozen plasma units (p = 0.002), and platelet concentrate (p = 0.01) requirements. These data suggest that aprotinin is effective in reducing bleeding and blood transfusion requirements during descending thoracic or thoracoabdominal aortic aneurysmectomy using CPB.

Adult↗
PubMed1994

Another application of two-dimensional transesophageal echocardiography: spinal cord imaging. A preliminary report.

This prospective study was performed in 17 consecutive patients continuously monitored intraoperatively and postoperatively for cardiac function with two-dimensional (2D) TEE. Prior to systematic evaluation of spinal cord imaging by 2D TEE, the aims of this study were to determine: (1) the feasibility of such imaging, and (2) the relationship between spinal cord images and fixed structures (like vertebral bodies); 7.5 +/- 2.3 spinal segments were identified in the patients. There is a close relationship between the distance of the probe from the teeth and the intervertebral disc. Successful imaging of the spinal cord was achieved in all 17 patients with visualization of discs, spinous processes, spinal canal, and a pulsating spinal cord. Further studies are needed to better define the potential applications of this new technique: detection of spinal cord trauma, visualization of a thoracic epidural catheter, and successful preservation of spinal cord vascularization during thoracic aortic surgery.

Cervical Vertebrae↗
PubMed1994

Hypothermic circulatory arrest for thoracic aneurysmectomy through left-sided thoracotomy.

PURPOSE: In an attempt to clarify the role of hypothermic circulatory arrest (HCA) in the management of complex aortic aneurysms operated on through the left thoracotomy, our technique of HCA and outcome were reviewed. METHODS: During a 21-month period, 15 (17%) of 87 aneurysms of the descending thoracic or thoracoabdominal aorta were operated on by HCA. Eleven patients had chronic aortic dissections (four type A and seven type B), two patients had atherosclerotic aneurysms, and one each had congenital or infected postoperative aneurysms. The use of HCA was planned before surgery in 14 patients. Indications included proximal aortic disease in 12 patients, making either clamping of the transverse aortic arch unsafe (eight patients) or necessitating replacement of the arch with a graft (four patients). Preoperative decision to use HCA was made in two additional patients, one with a ruptured aneurysm and another patient for spinal cord and visceral protection because of anticipated prolonged ischemia as a result of reoperation. Intraoperative technical difficulties prompted the use of HCA in only one patient. Deep hypothermia (15 degrees to 24 degrees C) was induced through partial cardiopulmonary bypass. Left-sided heart venting was necessary in five patients. Aortic replacement was limited to the descending thoracic aorta in five patients, whereas it involved the thoracoabdominal aorta in 10 patients. Four patients had associated replacement of the aortic arch. RESULTS: Three patients died (one of a ruptured aneurysm) during surgery or early after surgery (two of bleeding and one of left ventricular failure). All other patients awoke neurologically intact, but one patient had delayed onset of paraplegia. Another patient died 4 days after surgery of rupture of the ascending aorta. Eleven patients were perioperative survivors without significant morbidity. CONCLUSIONS: Hypothermic circulatory arrest is a valuable adjunct in the management of complex aortic aneurysms through left-sided thoracotomy. Its results warrant consideration of its selective use for spinal cord/visceral protection.

Adult↗
PubMed1994

Aberrant subclavian artery: surgical treatment in thirty-three adult patients.

PURPOSE: Because of the scarcity of large series in the literature, our experience with surgery for aberrant subclavian arteries (aSA) in adults was reviewed. METHODS: During the last 16 years we have surgically treated 33 adult patients with aSA. Twenty-eight patients had a left-sided aortic arch with a right aSA whereas five had a right-sided aortic arch with a left aSA. Eleven patients (group 1) had dysphagia caused by esophageal compression by a nonaneurysmal aSA; five patients (group 2) had ischemic symptoms caused by occlusive disease of a nonaneurysmal aSA; 10 patients (group 3) had aneurysms of the aSA with or without symptoms caused by esophageal compression or arterial thromboembolism; and seven patients (group 4) had an aSA arising from a diseased (usually aneurysmal) thoracic aorta. In all cases the divided aSA was revascularized, most often by direct transposition into the ipsilateral common carotid artery. Nine of the 16 patients in groups 1 and 2 underwent operation with a cervical approach alone. In the remaining seven, the cervical approach was combined with a median sternotomy (six cases) or a left thoracotomy (one case). In the 17 patients in groups 3 and 4, either a cervical approach (two cases), a median sternotomy (four cases), or a two-staged approach combining a supraclavicular incision on the side of the aSA with a posterolateral thoracotomy on the side of the aortic arch (11 cases) was used. Aortic cross-clamping was required in 12 of these patients to perform the transaortic closure of the origin of the aSA with patch angioplasty (three cases), or prosthetic replacement of the descending thoracic aorta (nine cases). Cardiopulmonary bypass was used in six patients (including three with hypothermic circulatory arrest). RESULTS: Four patients, all in groups 3 and 4, died after operation: two of multiorgan failure, one of heart failure, and one of esophageal rupture. Satisfactory clinical and anatomic results were obtained in the remaining 29 patients. CONCLUSIONS: The surgical approach to aSA must be flexible and adapted to the anatomic conditions found. We recommend routine reconstruction of the aSA to avoid ischemic complications in the vertebrobasilar territory or upper extremity. Provision should be made for cardiopulmonary bypass in patients with aneurysm of aSA or associated aortic aneurysm.

Adolescent↗
PubMed1994

High-frequency jet ventilation vs continuous positive airway pressure for differential lung ventilation in patients undergoing resection of thoracoabdominal aortic aneurysm.

Twenty patients, scheduled for surgical resection of thoracoabdominal aortic aneurysm were divided into two groups according to the type of differential lung ventilation used during graft replacement of the descending thoracic aorta. In the high-frequency jet ventilation (HFJV) group of ten patients, HFJV was applied to the left lung once collapsed and retracted by the surgeon, the patient lying in the right lateral decubitus and being intubated by a Carlens' tube. In the continuous positive airway pressure (CPAP) group of ten patients, CPAP was applied to the left lung at the same mean airway pressure as HFJV (1 kPa). Before anaesthetic induction, an arterial and a Swan-Ganz catheter were inserted for cardiovascular monitoring. The same anaesthetic technique using fentanyl 6 micrograms.kg-1, flunitrazepam 0.02 mg.kg-1 and pancuronium 0.1 mg.kg-1 was used for each patient. Haemodynamic and respiratory measurements were made; 15 min after positioning the patients in the right lateral decubitus using two-lung ventilation; 15 min after collapse and retraction of the left lung using one-lung ventilation and 15 min after using differential lung ventilation with CPAP or HFJV. Left lung collapse with conventional one-lung ventilation induced a dramatic decrease in arterial oxygenation: PaO2/FIO2 ratio decreased from 43 +/- 6 kPa to 20 +/- 8 kPa, alveolo-arterial oxygen difference increased from 24 +/- 7 kPa to 72 +/- 11 kPa and pulmonary shunt increased from 17 +/- 2% to 37 +/- 3%. Whereas differential lung ventilation with CPAP did not improve any of the respiratory parameters measured, differential lung ventilation with HFJV, significantly increased PaO2/FIO2 ratio to 41 +/- 14 kPa.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Loops and folds of the carotid and vertebral arteries: indications for surgery].

Tortuous variants of the carotid or vertebral morphology are apparent on 10 to 43% of angiograms. It is probable that the incidence of these anomalies is lower in the normal population. Rarely, their etiology is congenital explaining the existence of some pediatric cases. The etiology of most cases is acquired and linked with hypertension, atheroma and aging. Basically consisting of an excess of length of the common or the internal carotid artery, the tortuosity may take the form of simple or multiple kinking, coiling or looping. Isolated, these anomalies are asymptomatic in a large majority of the cases. However, hemispheric, vertebrobasilar or ocular ischemic symptoms may be caused by them through a thromboembolic or hemodynamic mechanism. Moreover, given their frequent association with atherosclerotic occlusive lesions, their participation in the production of ischemic symptoms is not easy to determine. Although not yet investigated by prospective randomized studies, symptomatic isolated of kinking or coiling of cerebral arteries are amenable to surgical revascularization in order to prevent stroke or blindness. Besides, the endarterectomy of atherosclerotic occlusive lesions of tortuous carotids requires a technical adaptation.

Adult↗