Biomedical subjects

J Jean-Claude

Publications and source records attributed to J Jean-Claude.

9 recordsLinked to original sources

PubMed2001

Determinates of functional disability after complex upper extremity trauma.

This is a retrospective chart review of 71 patients who were operated on for presumed upper extremity arterial trauma between June 1992 and June 1998. Penetrating trauma occurred in 50 (70%) patients, and blunt trauma in 21 (30%). There were 2 innominate, 6 subclavian, 13 axillary, 26 brachial, 5 radial, 6 ulnar, and 6 multiple arterial injuries. There were 7 negative explorations (4 venous injuries, 2 false-positive angiograms, and 1 branch artery injury). In addition to the vascular injury, 44 patients (69%) had another injury in the extremity, including 8 (12.5%) orthopedic injuries, 12 (19%) nerve injuries, and 24 (37.5%) combination nerve and orthopedic injuries. There were three arterial thromboses, one arterial disruption, and four amputations, resulting in a patency rate and limb salvage rate of 94%. Persistent disability was more common in those patients with blunt injury (p = 0.02) and in those patients with associated neurologic and orthopedic injuries (p < 0.05). Full functional recovery was seen in 21 (33%) patients, while some form of disability was noted in the remaining 67%. The magnitude of the concomitant neurologic injury was the major determinate of functional outcome in this patient population.

Adolescent↗

PubMed2001

Analysis of initial CT findings after endovascular repair of abdominal aortic aneurysm.

PURPOSE: To determine the spectrum and frequency of specific computed tomographic (CT) findings in the acute period after endovascular repair of abdominal aortic aneurysm (AAA). MATERIALS AND METHODS: CT images obtained 1--3 days after endograft placement were evaluated in 88 patients. The images were analyzed for stent position, appearance of endograft components, perigraft leak, and postoperative findings including air and acute thrombus within the aneurysm and air surrounding the femoral-femoral bypass graft. Findings that could be misinterpreted as perigraft leak were evaluated. RESULTS: Fifteen (17%) of 88 patients had perigraft leak in the acute postoperative period. The bare segment of the proximal self-expanding stent covered one or both renal arteries in 54 (61%) patients. One patient had CT evidence of renovascular compromise. Postoperative air was within the aneurysmal sac in 51 (58%) patients and surrounded the femoral-femoral bypass graft in 67 (94%) of 71 patients in whom the grafts were evaluated with CT. Mottled attenuation within the aneurysmal sac was seen in 50 (57%) patients. Forty-six (52%) patients had calcifications within longstanding thrombus. In 31 (35%) patients, findings that could have been misinterpreted as perigraft leak were identified. CONCLUSION: Accurate analysis of CT findings after endovascular AAA repair requires careful review of all available CT images (preprocedural and pre- and postcontrast) and clear understanding of specific stent-graft components and placement.

Aged↗

PubMed2000

Intraoperative carotid evaluation.

HYPOTHESIS: Intraoperative duplex scanning can identify technical defects and increase the quality of carotid artery repair. DESIGN: We evaluated 100 consecutive carotid operations in 96 patients (60 men and 36 women) from 1995 to 1998. Spectral-derived peak systolic flow velocities (PSV) were graded (PSV < 100 cm/s, normal laminar flow; PSV 100-150 cm/s, mild or moderate flow disturbance; PSV > 150 cm/s, severe flow disturbance). Prospective criteria for intraoperative revision included PSV greater than 150 cm/s, spectral broadening, and B-mode imaging of intimal flaps or intraluminal debris. Preoperative, intraoperative, and 6-week follow-up duplex scan results were analyzed. SETTING: All patients were evaluated and treated at a single academic institution. INTERVENTIONS: All procedures were performed with the patient under general endotracheal anesthesia; 86% underwent shunting and 70% underwent patching. MAIN OUTCOME MEASURE: Number and type of revisions, patency of repair, residual and recurrent stenosis, and ipsilateral neurologic events. RESULTS: There were 33 intraoperative duplex studies with abnormal findings. Seven involved the common carotid artery and resulted in intraoperative revision of 5 intimal flaps at the site of the proximal clamp. In 11 patients, incomplete eversion endarterectomy resulted in elevated distal intimal flaps in the external carotid artery that were repaired through a separate arteriotomy. There were 15 abnormalities in the internal carotid artery prompting 5 revisions. Five studies with PSV of 100 to 150 cm/s had no defects on B-mode imaging and were observed without treatment. Five false-positive studies were attributed to increased flow velocity due to contralateral occlusive discase. At 6 weeks' follow-up, 4 of 5 repaired common carotid arteries were normal on duplex scan and 1 had a mild residual stenosis. Ten of the 11 external carotid repairs were patent and 1 was occluded. Four of the 5 internal carotid artery repairs were normal on postoperative evaluation and 1 had a mild residual stenosis. Of the 10 abnormal internal carotid arteries that were observed, 9 were normal on postoperative duplex and 1 had a mild residual stenosis. One perioperative stroke occurred in a patient with a normal, patent carotid repair. CONCLUSIONS: Intraoperative duplex evaluation of carotid reconstruction is an efficient, sensitive tool that can detect technical lesions that will jeopardize surgical reconstruction. Interpretive judgment is required because all flow disturbances do not dictate surgical intervention. This technique enables the surgeon to maximize the quality of the arterial reconstruction during carotid artery surgery.

Aged↗

PubMed2000

Metalloproteinase levels are decreased in symptomatic carotid plaques.

BACKGROUND: Matrix metalloproteinase enzymes (MMP) have been identified in carotid atherosclerotic plaques, but their role in the development of clinical symptoms remains ill defined. We correlated the activity and levels of metalloproteinase enzymes and their inhibitors in human carotid plaques to ischemic neurologic events. METHODS: Carotid plaques were collected at the time of endarterectomy from 23 patients with carotid stenosis. Sixteen patients were asymptomatic and 7 patients had symptoms of stroke or transient ischemic attack within 6 weeks of surgery. Protein was extracted from the plaques, proteolytic activity was determined by gelatin zymography, and pro-MMP and tissue inhibitor of metalloproteinase (TIMP) enzyme content were measured by ELISA assay. Macrophage accumulation in the plaque was determined using immunohistochemistry. RESULTS: Plaques from symptomatic patients had decreased proteolytic activity on substrate gel zymography at the 62- and 92-kDa regions (corresponding to active MMP-2 and pro-MMP-9). A decrease in pro-MMP-9 (8.21 +/- 2.35 vs 17.42 +/- 3.14 ng, P < 0. 05) and an increase in TIMP-2 protein (12.62 +/- 0.58 vs 10.56 +/- 0. 77 ng, P < 0.05) were noted on ELISA in plaques from symptomatic patients. No difference was noted in macrophage accumulation in the plaques between the two groups. CONCLUSIONS: Plaques from patients who present with ischemic neurologic symptoms have decreased proteolytic activity associated with decreased pro-MMP-9 and increased TIMP-2 protein levels. These data suggest that metalloproteinase enzymes are not responsible for plaque instability in the carotid circulation and may in fact promote plaque stability.

Aged↗

PubMed2000

Aortic stent-grafts in patients with renal transplants.

PURPOSE: To report the endovascular treatment of abdominal aortic aneurysms (AAA) in 2 patients with pelvic renal transplants. METHODS AND RESULTS: Two men with multiple comorbidities and pelvic transplant kidneys underwent endovascular AAA repair using an aortomonoiliac system with femorofemoral bypass grafting. The arterial end-to-side anastomosis in both patients was to the external iliac artery. Tapered aortomonoiliac grafts were fashioned from Gianturco Z-stents covered with Dacron graft material and implanted with the distal attachment site in the iliac system ipsilateral to the transplant kidney arterial anastomosis. The body of the stent-graft was reinforcement with a Wallstent in each case before the contralateral common iliac artery was occluded and the cross-femoral bypass constructed. Both patients recovered uneventfully from the procedure and are free of endoleak or other complications related to their aneurysm repair at 7 and 34 months. CONCLUSIONS: The presence of a pelvic renal transplant in a patient undergoing endovascular AAA repair increases the complexity of procedural planning and endograft implantation, but a good outcome can be achieved.

Aged↗

PubMed1999

Abdominal aortic aneurysm in high-risk patients: short- to intermediate-term results of endovascular repair.

PURPOSE: To assess the safety and efficacy of endovascular repair of abdominal aortic aneurysm in high-risk patients during the short to intermediate term. MATERIALS AND METHODS: Endovascular aneurysm repair was performed in 50 patients considered too high risk for conventional repair. Stent-grafts were inserted through surgically exposed femoral arteries with fluoroscopic guidance. The anesthetic technique was epidural in 36 patients, general in 12, and local in two. Aortouniiliac stent-grafts were inserted in 42 patients and aortoaortic in eight. RESULTS: There were no deaths and no conversions to open surgical repair. The primary success rate (complete aneurysm exclusion according to CT criteria) was 88% (44 of 50). The secondary, clinical, and continuing success rates were all 98% (49 of 50). Surgical time was 196 minutes +/- 67 (mean +/- SD), blood loss was 284 mL +/- 386, and volume of contrast material administered was 153 mL +/- 64. The time from the end of the surgery to resumption of a normal diet was 0.58 days +/- 0.56, to ambulation was 1.22 days +/- 0.77, and to discharge from the hospital was 3.63 days +/- 1.60. Wound problems accounted for the majority of complications. There were no instances of pulmonary failure, renal failure, stent-graft migration, or late leakage. CONCLUSION: Endovascular repair of abdominal aortic aneurysm is feasible in two-thirds of high-risk patients, with a low mortality and high success rate during the short to intermediate term.

Aged↗

PubMed1994

Cellular localization of matrix metalloproteinases in the abdominal aortic aneurysm wall.

PURPOSE: This study explores the source(s) of the matrix-degrading proteinases, matrix metalloproteinase 1 (MMP-1; interstitial collagenase), matrix metalloproteinase 3 (MMP-3; stromelysin 1), and matrix metalloproteinase 9 (MMP-9; gelatinase B), previously implicated in abdominal aortic aneurysm (AAA) development. The possible involvement of the plasmin cascade in the activation of these proteinases was also explored by examining the presence of the urokinase-type plasminogen activator (uPA) in aneurysm wall. METHODS: Immunohistochemical techniques were used to detect the presence of MMP-1, MMP-3 and MMP-9 proteins and uPA in fixed, paraffin-embedded tissue sections from AAA (n = 10) and control (n = 2) aortas. RESULTS: The MMP-9 protein was localized to mononuclear cells in the AAA wall. Dual-labeling techniques confirmed the identity of these cells as macrophages. The MMP-3 protein and uPA were also detected primarily in the macrophage-like mononuclear cells infiltrating the aneurysmal aorta. Immunoreactive material to MMP-1 was demonstrated in mesenchymal cells of the AAA wall suggesting alternative expression and delivery of this enzyme in AAA. CONCLUSIONS: This work establishes the role of macrophages in the delivery, expression, and possible activation of matrix destructive proteinases during AAA pathogenesis and suggests a role for the activation of MMPs in the progression of the disease.

Antibodies, Monoclonal↗

PubMed1994

Cytokines that activate proteolysis are increased in abdominal aortic aneurysms.

BACKGROUND: Abdominal aortic aneurysm (AAA) disease is characterized by an increase in proteolysis and loss of matrix components. The cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta), products of activated macrophages and T cells, are known to increase the production of matrix-degrading enzymes in some pathological states. METHODS AND RESULTS: Seven AAA and five control aortic tissue extracts were assayed for TNF-alpha and IL-1 beta with ELISA. TNF-alpha was elevated significantly in AAA extracts compared with controls (86 +/- 34 pg/mg of total protein versus 1 +/- 1 pg/mg of total protein; P < .001). IL-1 beta concentration also was significantly increased in the AAA specimens (48 +/- 14 pg/mg of total protein versus 12 +/- 5 pg/mg of total protein; P < .05). Immunoblotting demonstrated secreted forms of TNF-alpha in the AAA extracts, and possible membrane-bound forms were observed when the tissues were detergent-extracted. Known forms of IL-1 beta also were observed on immunoblots of AAA tissue extracts. CONCLUSIONS: The presence of TNF-alpha and IL-1 beta in AAA tissue underscores the importance of the infiltrating inflammatory cells present in the media and adventitia of aneurysmal aortic wall and further implicates an inflammatory process in the pathogenesis of AAA.

Aorta, Abdominal↗

PubMed1994

Possible key role for plasmin in the pathogenesis of abdominal aortic aneurysms.

BACKGROUND: Activation of proteolysis is characteristic of abdominal aortic aneurysm (AAA) disease, and by substrate gel enzymography with casein the most conspicuous proteinase of AAA wall has a molecular weight of approximately 80 kd. This activity has been resolved into separate metalloproteinase and serine proteinase (SP) components, by binding out the metalloproteinase by affinity to tissue inhibitor of metalloproteinases. Because plasmin plays a key role in activating members of the metalloproteinase family, the following experiments were done to test the hypothesis that the unknown SP is plasmin. METHODS: Immunoblots, immunoprecipitations, and immunohistochemistry were performed by conventional methods with a specific polyclonal antibody to plasminogen. RESULTS: Immunoblot analysis of extracts from AAA specimens (n = 7) revealed dense bands corresponding to known molecular forms of plasmin. Only trace amounts were detected in control aortic extracts (n = 4). When samples were equalized for total protein, the mean amount of immunoreactive material in the 80 kd band (in densitometric units) was 216 +/- 44 (SEM) for AAAs versus 27 +/- 15 (SEM) for controls (p < 0.01). The residual 80 kd SP activity on casein substrate gel enzymography was quenched by immunoprecipitation with the specific antibody. Immunohistochemistry revealed strong reactivity of the AAA wall. CONCLUSIONS: Because plasmin plays a key role in the cascade for activation of the matrix metalloproteinase (including collagenase and the metalloelastases), the present results suggest that plasmin may be important in the sequence of events leading to the destruction of aortic matrix in AAA.

Aortic Aneurysm, Abdominal↗