Biomedical subjects

J Eldrup-Jorgensen

Publications and source records attributed to J Eldrup-Jorgensen.

30 records · Page 2Linked to original sources

PubMed1989

Lupus-like anticoagulants and lower extremity arterial occlusive disease.

Lupus-like anticoagulants (LLA), lupus anticoagulant and/or anticardiolipin antibody, are increasingly recognized in association with venous and arterial thrombotic events. We recently reviewed our experience with patients undergoing revascularization for lower-limb ischemia who were found to have LLA. Nine patients had LLA based on a prolongation of the partial thromboplastin time or by anticardiolipin assay by an enzyme-linked immunosorbent assay system. The ages of the patients ranged from 23 to 57 years. There were seven (78%) men, six (67%) blacks, two (22%) diabetic patients, and three (33%) hypertensive patients. One patient had systemic lupus erythematosus. All patients except one were cigarette smokers. Four patients had concurrent regulatory protein abnormalities: three protein C deficiencies, one protein S deficiency, and one plasminogen deficiency. The nine patients had 10 lower-extremity arterial reconstructions with two postoperative failures within 30 days. Patients were anticoagulated with heparin or aspirin after all but one operation. Patients at risk were identified on the basis of age (less than 51 years), unexplained early graft thrombosis, or history of venous or arterial thrombotic events. This group of patients is believed to be at risk for early postoperative thrombosis. Postoperative anticoagulation after revascularization for patients with LLA may be beneficial.

Adult↗

PubMed1988

Risk factors affecting the natural history of intermittent claudication.

To determine the prognostic significance of the level of arterial disease in claudicators, risk factors affecting the progression of intermittent claudication, including hemodynamic variables obtained from noninvasive vascular laboratory examinations, were assessed. We identified 378 patients with intermittent claudication by characteristic history and the presence of abnormal treadmill exercise examination results. Results of serial examinations were available for 195 of these patients, who had 310 claudicating limbs. Life-table analysis revealed that after eight years, 41% of these patients had progressed to critical ischemia, defined as rest pain or tissue loss, and 50% had died. Cox proportional hazards general linear regression analysis found that at a patient's first examination in the vascular laboratory, the ankle-brachial index and the decrease in ankle-brachial index after exercise were significantly associated with the subsequent development of critical ischemia. The level of disease at the initial examination in the vascular laboratory was not a significant risk factor for progression to critical ischemia and therefore should not be used as an indicator for or against operation in patients with intermittent claudication.

Adult↗

PubMed1988

Analysis of 18 recent cases of penetrating injuries to the common and internal carotid arteries.

Penetrating injuries to the common and internal carotid artery carry the unique potential for irreversible neurologic damage, respiratory collapse, and exsanguination. This study analyzes a recent 4 year experience with 18 cases of penetrating injury to the carotid artery to identify the factors influencing surgical decision-making, perioperative complications, and mortality. Sixteen patients with acute respiratory distress required emergent airway intubation. Three patients in hemorrhagic shock were brought directly to the operating room; the remaining 15 underwent emergency carotid arteriography. Three patients with multiple intramediastinal vascular injuries exsanguinated on the operating table before hemorrhage could be controlled. There were no deaths or neurologic complications in the 14 surviving patients who had an operation on the carotid artery, including 2 patients treated by internal carotid artery ligation. Early control of the airway was the most common initial requirement in this group of patients. Judicious use of preoperative arteriography was thought to facilitate the operative approach in selected patients. A flexible surgical approach to the damaged carotid artery is essential based on the patient's hemodynamic status, degree of neurologic impairment, and nature and extent of arterial damage.

Adolescent↗

PubMed1988

Long-term results of infragenicular bypasses with autogenous vein originating from the distal superficial femoral and popliteal arteries.

Forty-nine bypasses originating from the distal superficial femoral artery or popliteal artery in 46 patients were reviewed to examine late patency, limb salvage, and factors leading to graft failure. Operations were performed because of tissue loss in 86%, rest pain in 12%, and limiting claudication in 2% of limbs. Proximal anastomosis was from the distal superficial femoral artery in 12% and the popliteal artery in 88%. Distal anastomosis was to the below-knee popliteal artery or proximal tibial vessels in 20% and the distal tibial vessels in 80%. Life-table analysis showed a primary patency rate of 83%, 62%, and 41%, at 1, 3, and 5 years, respectively. The rate of limb salvage at 6 years for all grafts was 69%. Cox proportional hazards analysis determined that stenosis of 20% or greater in the proximal superficial femoral artery before bypass was a significant risk factor for graft failure (p = 0.02) despite the presence of normal intra-arterial pressure at the site of the proximal anastomosis at the time of bypass. Long-term survival in these patients was low, with a 6-year survival rate of only 24%. Infragenicular bypasses originating from the distal superficial femoral artery or the popliteal artery can be performed with patency and limb salvage rates comparable to bypasses originating from the common femoral artery. These bypasses are more likely to fail when performed in the presence of a stenosis 20% or greater in the superficial femoral or popliteal artery proximal to the graft origin.

Aged↗

PubMed1988

The systemic activation of platelets by Dacron grafts.

Dacron (polyester fiber), a stimulus to platelet aggregation in vitro, accumulates platelets to a greater extent in vivo than autogenous artery, polytetrafluoroethylene (PTFE) or human umbilical vein (HUV). We conducted a series of experiments using the ex vivo shunt in the baboon to determine whether or not systemic activation of platelet function was produced by a Dacron graft. Two 5 centimeter segments of 4 millimeter internal diameter graft materials were placed in series in the ex vivo shunt perfused at 25 milliliters per minute flow rate for two and one-half hours. Deposition of autologous Indium 111 labeled platelets was monitored. The ex vivo shunt procedures were divided into two groups, both with PTFE as the proximal graft: one with a distal Dacron graft (n = 21), the second with PTFE or HUV distally (n = 17). In this study, an increase in platelet deposition on the proximal PTFE graft represents systemic platelet activation caused by the distal graft. Increased platelet deposition on PTFE was noted at all time points in the presence of a Dacron graft (p less than 0.05). This property of Dacron has important clinical implications, potentially accelerating the progression of vascular disease, increasing the failure rate of composite grafts and subsequent arterial reconstruction.

Animals↗

PubMed1988

A prospective, randomized trial of Unna's boots versus hydroactive dressing in the treatment of venous stasis ulcers.

In many centers the standard treatment for venous stasis ulcers consists of UB dressings. A new dressing, DuoDERM hydroactive dressing (HD), has recently been used extensively for the treatment of venous stasis ulcers. Because of this trend, a prospective, randomized trial of these two dressings was undertaken. Sixty-nine ulcers (39 HD and 30 UB) were randomized. End points were complete healing and development of complications necessitating cessation of treatment. Time to healing, cost of treatment, and patient convenience were also evaluated. Twenty-one of 30 ulcers (70%) healed with UB therapy compared with 15 of 39 ulcers (38%) treated with HD (p less than 0.01, CST). Life-table healing rates at 15 weeks were 64% for UB compared with 35% for HD (p = 0.01, log rank test). Ten of 39 patients (26%) receiving HD had complications compared with no complications in the UB group (p = 0.004, FET). For those patients whose ulcers healed, there was no significant difference (p = 0.51, STT) in the mean time required for healing or the average weekly cost of dressing materials between the HD group (7.0 weeks at +11.50 per week) and the UB group (8.4 weeks at +12.60 per week). Those patients treated with HD reported a significantly greater level of convenience than those patients with UB (p = 0.004, STT). Although treatment with HD led to better patient acceptance, those patients receiving UB therapy had a significantly greater rate of healing and a significantly lesser incidence of complications than those patients treated with HD.

Bandages↗

PubMed1987

The effect of low molecular weight dextran on platelet deposition onto prosthetic materials.

Low molecular weight dextran (LMD) has recently been shown in a randomized, multicenter trial to improve early patency in difficult lower extremity vascular bypass. The question remained as to whether this effect was due to plasma volume expansion by LMD or to its effects on platelets and coagulation. To analyze this we have studied the effects of LMD on platelet-graft interactions using an ex vivo baboon shunt. Indium 111-labeled autologous platelet deposition on expanded polytetrafluoroethylene and knitted Dacron grafts was monitored at a flow rate of 25 ml/min for 21/2 hours. LMD was given by intravenous bolus at a dose of 5 ml/kg and was followed by a continuous infusion of 10 ml/hr. Flow through the shunt was started after the initial dextran bolus. Control studies were performed in a similar manner without dextran. An additional series of experiments was performed with a 5 to 10 ml/kg bolus of 5% human serum albumin to analyze the contribution of plasma volume expansion to platelet deposition in this model. The results revealed a significant (p less than 0.05) reduction in platelet deposition on both graft materials with the LMD infusion. No difference was seen between the control group and the albumin group. These studies provide direct in vivo evidence of the antiplatelet effect of LMD.

Albumins↗

PubMed1987

The early fate of venous repair after civilian vascular trauma. A clinical, hemodynamic, and venographic assessment.

Repair of major venous injuries of the extremities has been advocated to improve limb salvage rates and to prevent the early and late sequelae of venous interruption. The contribution of venous repair to the surgical outcome remains controversial, however, in part because the fate of venous reconstruction has previously not been well defined. The current study was done to determine the early patency rate of venous repair, to compare the accuracy of various methods used to assess venous patency, and to analyze the relationship between early venous patency and surgical outcome. During a recent 27-month period, 36 patients with major extremity venous injuries were treated by venous reconstruction; 34 patients (94%) had an associated major arterial injury that also required repair. Venous repair was performed in the upper extremity (22%) as well as the lower extremity (78%) using various reconstructive methods, including lateral repair (17%), end-to-end anastomosis (11%), autogenous vein patching (25%), interposition autogenous vein grafting (42%), and panelled autogenous vein grafting (6%). After operation, venous repair patency was evaluated by clinical examination, impedence plethysmography, and Doppler ultrasonography, and contrast venography. There were no perioperative deaths in these 36 patients. The limb salvage rate was 100% and all 34 major arterial repairs were patent at the time of hospital discharge. Venography performed on the seventh postoperative day demonstrated that 14 venous repairs had thrombosed (39%) and that 22 had remained patent (61%). Local venous repair had a significantly lower thrombosis rate (21%) than those requiring interposition vein grafting (59%) (p less than 0.03). Compared with venography, the clinical evaluation was 67% accurate in the assessment of venous repair patency, and the noninvasive examination was 53% accurate. In conclusion, a substantial percentage of venous repairs will thrombose in the postoperative period, especially if interposition vein grafting is used. However, in this series limb salvage was not adversely influenced by an unexpectedly high rate of venous repair thrombosis. In addition, clinical evaluation and noninvasive testing did not provide an accurate assessment of venous patency after venous repair.

Adolescent↗

PubMed1986

Antiplatelet therapy and vascular grafts. Studies in a baboon ex vivo shunt.

Antiplatelet therapy is currently recommended in an effort to improve patency rates of small-caliber vascular grafts. The effect of aspirin and heparin on acute platelet deposition was studied in a baboon ex vivo shunt. Two grafts, expanded polytetrafluoroethylene and knitted Dacron, were exposed to a flow rate of 25 mL/min after administration of aspirin or heparin. Indium 111-labeled platelet uptake by the grafts was determined over 2 1/2 hours. The amount of platelet deposition in the treated groups was significantly less than that of controls after 2 1/2 hours. There was no difference between the aspirin and heparin groups. The finding that heparin inhibited platelet deposition to a degree comparable with aspirin suggests that it may not be necessary to start antiplatelet therapy preoperatively. Intraoperative systemic heparinization will provide sufficient inhibition of platelet deposition. A protocol for perioperative antiplatelet therapy is outlined.

Animals↗

PubMed1986

The role of cranial computed tomography in carotid surgery.

In patients who present with TIA, RIND, or CVA, the cranial CT scan can rule out other etiologies for neurologic symptoms. In addition to the clinical presentation, the CT scan allows further stratification of patients being considered for carotid endarterectomy. We propose that patients be classified as TIA (+), TIA (-), RIND (+), or CVA (-). The CT scan has defined a new subgroup of patients, TIA (+) and RIND (+)--the Silent Cerebral Infarction. Patients who are categorized as TIA (+), RIND (+), and CVA (+) (cerebral infarction on CT or by history) are at increased risk for intraoperative ischemia and postoperative neurologic deficit. As such, they should be selectively shunted based on intraoperative EEG monitoring or routinely shunted. There is a strong association between ulcerative plaque at the carotid bifurcation and cerebral infarction on CT. The CT scan is a critical diagnostic procedure in evaluating the patient with an acute neurologic event. Patients with negative CT scans are candidates for early operation. Carotid endarterectomy should generally be delayed for 4 to 6 weeks in patients with positive CT scans.

Acute Disease↗

PubMed1986

Endothelial cell seeding of small-caliber synthetic grafts in the baboon.

Endothelial cell (EC) seeding has been proposed as a method to improve the performance of small-caliber synthetic vascular prostheses. Seeding experiments to date have all been carried out in the dog. This study investigates EC seeding of small-caliber Dacron carotid interposition grafts compared with contralateral control grafts in the baboon. Surface thrombogenicity was assessed at 24 hours, 2 weeks, and 4 weeks after implantation with indium 111-labeled autologous platelets. Morphologic and immunohistochemical techniques were used to assess the identity and homogeneity of the EC inoculum before seeding and to identify cell types on the harvested grafts. There was no significant difference in patency rates between seeded and control grafts at 5 weeks. Platelet accumulation on seeded grafts was significantly less (p less than 0.05) than on paired controls at 2 and 4 weeks after implantation. The luminal lining of seeded grafts had more cellular ingrowth, less adherent thrombus, and more surface cells with the morphologic and histochemical characteristics of EC than did the lining of controls. EC seeding reduces the platelet reactivity and accelerates EC coverage of small-caliber grafts in the baboon.

Animals↗

PubMed1985

Evaluation of arterial prostheses in a baboon ex vivo shunt: the effect of graft material and flow on platelet deposition.

Surface thrombogenicity is recognized as an important factor in the failure of small caliber vascular prostheses. The baboon ex vivo shunt was developed to study small caliber grafts under controlled conditions at different flow rates. The shunt was created by percutaneous insertion of catheters into the baboon femoral artery and vein. Platelet-graft interactions were studied using autogenous indium 111 labeled platelets. Two graft materials were placed in series and exposed to blood flow for 2 1/2 hours at flow rates of 25 and 200 ml/min. At the end of this period, the grafts were removed for morphologic examination. Platelet adhesion to the grafts, especially with the less thrombogenic materials (PTFE and HUV), was found to be independent of flow rate. PTFE was found to be the least platelet-reactive material, HUV was intermediate, and knitted Dacron was the most thrombogenic surface. Platelet deposition on the flow surface was confirmed by light microscopy and scanning electron microscopy.

Animals↗