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N Chakfé

Publications and source records attributed to N Chakfé.

30 records · Page 2Linked to original sources
PubMed1999

[Paraplegia secondary to surgery of the abdominal aorta].

We report the case of an 84 year-old man who suffered of paraplegia after surgery of an abdominal aortic aneurysm. The neurologic status did not improve during 5 years of follow-up. This complication is rare in light of the review of the literature. It is more frequent after emergency (1.4%) and redux (19%) surgery than after elective surgery (1.1%). Its mechanisms are anatomic (occlusion of the Adamkievitz artery and of the pelvic collateral arteries) and hemodynamic mechanisms (thromboembolism, low systemic tension, long supra-renal clamping). Since pre-operative aortography to detect anatomic variations is not realistic, its only prevention remains maintenance of intra-operative hemodynamic, systemic heparinization, and preservation of the pelvic collateral circulation.

Aged↗
PubMed1997

Albumin-impregnated prosthetic graft for infrarenal aortic replacement: effects on the incidence and volume of perioperative blood transfusion.

We retrospectively reviewed 290 cases in which an albumin-impregnated polyester prosthetic graft was used for surgical management of aortic bifurcation disease between November 1987 and December 1990. The purpose of this review was to determine the incidence and volume of blood transfusion and to evaluate the rate of patency and the incidence of infection achieved using this type of prosthesis. The indication for surgery was abdominal aortic aneurysm (AAA) in 218 cases (190 elective procedures and 28 emergency procedures) and occlusive disease of the aortic bifurcation (ODAB) in 72 cases. Mean follow-up was 25.5 +/- 13.4 months (range: 1 and 50 months). The incidence of blood transfusion for elective AAA and ODAB surgery was 30.2% and 32.3% intraoperatively, 21.3% and 12.9% postoperatively, and 40.4% and 42.6% overall. The mean number of red cell packs transfused for elective AAA and ODAB surgery was respectively 1 and 0.8 intraoperatively, 0.4 and 0.6 postoperatively, and 1.4 and 1 overall. No immediate or late graft infection prosthesis was observed in any patient in this series. Primary and secondary patency was 95.5% and 97.5% at 6 months with no graft thrombosis during further follow-up. The fact that use of an impregnated graft in management of aortic bifurcation disease was accompanied by a high incidence and volume of blood transfusion suggests that these grafts do not reduce perioperative blood loss. Use of an impregnated prosthesis had no effect on the rate of patency and the incidence infection.

Aged↗
PubMed1997

Clinical presentation and treatment options for mitral valve myxoma.

Myxomas rarely are located on the mitral valve. We report the case of a 44-year-old man operated on successfully with mitral valve conservation, which is the 21st case of mitral valve myxoma reported in the western literature. Among the cases reported in the literature, the diagnosis was made at the time of autopsy in 6 cases, with premortem heart failure in 1 case. A clinical diagnosis was made in 15 cases on the basis of the following symptoms: peripheral embolism in 9 cases, cardiac signs in 4 cases, and constitutional manifestations in 2 cases. The clinical presentation of mitral valve myxoma differs slightly from that of other cardiac myxomas in that it has a lower incidence of constitutional manifestations. The gold standard for noninvasive diagnosis and localization of cardiac myxomas is transesophageal echocardiography. It allows for the detection of early, small valvular tumors and may help to characterize better their location and echostructure, facilitating the choice of an optimal surgical approach through preoperative study of the integrity and mobility of the valve. Conservative operative treatment by resection of the area of implantation of the myxoma followed by suture repair of the valve and annuloplasty may be recommended as the most appropriate treatment option for this rare condition.

Adult↗
PubMed1997

[Extra-popliteal localizations of adventitial cysts. Review of the literature].

Cystic adventitial disease is an uncommon vascular anomaly first described in 1947 in the external iliac artery. The preferential localization is the popliteal artery although other arteries and veins may also be involved though not always recognized. There have been 45 extra-popliteal localizations of adventitial cysts reported in the literature. Thirty cases involved an artery an 15 a vein. The iliofemoral axis, with 33 reported cases, is the preferential localization of these extra-popliteal adventitial cysts (including 22 arteries and 11 veins). All the other cases also involved a vessel near an articulation (knee, ankle, elbow, wrist). Despite a preferential popliteal arterial localization only one case involved the popliteal vein. The diagnosis is rarely made before surgery, probably because of the nonspecific clinical presentation. Ultrasonography should allow better recognition of these adventitial cysts, eliminating an aneurysm or a synovial cyst, and evidencing the localization of the cyst within the vessel wall.

Cysts↗
PubMed1997

[Aortocaval fistula. Diagnosis using spiral x-ray computed tomography with 2D and 3D reconstructions].

We report a case of arteriovenous fistula due to spontaneous rupture of an aortic aneurysm into the inferior vena cava. This is a rare complication of atheromatous aneurysm, often difficult to diagnose as the clinical presentation may be obscure. Although aortography is the reference diagnostic investigation, spiral CT acquisition with 3D and 2D reformation allowed visualization of the arteriovenous communication and provided an accurate diagnosis.

Aged↗
PubMed1996

An albumin-coated polyester arterial graft: in vivo assessment of biocompatibility and healing characteristics.

The albumin-coated vascular graft (ACG) and its uncoated polyester substrate, the Vascular II (V-II), were evaluated in terms of biocompatibility and biofunctionality using two in vivo animal studies. Biocompatibility and immunoreactivity were assessed by implanting intraperitoneally in the rat small segments of the ACG and the V-II graft and harvesting them with their surrounding tissue 3d, 1, 2 and 4 weeks later. Cytofluorometric determination of total T cells (CD3), the ratio of CD4/CD8 subsets and the percentage of IL-2 receptor-positive T cells in the peripheral blood has revealed that no significant difference in any of the T cell populations was found between the ACG and the V-II graft. The cellular reactivity of the ACG in terms of acid phosphatase activity at the implant side was significantly greater at 3 d but not at longer periods. Biofunctionality was evaluated by implanting both grafts as a thoracoabdominal vascular bypass in dogs for 11 different periods ranging from 4 h to 6 months. The rate of albumin resorption was such that traces were still present at 1 month, but no longer observable at 2 months. Tissue incorporation into the graft wall was earlier for the V-II (2 weeks) than for the ACG (4 weeks), which showed complete encapsulation, tissue incorporation and endothelialization after 2 months in vivo. Only small differences were observed between both grafts in terms of platelet and fibrin uptake on the luminal surface. The prostacyclin/thromboxane A2 ratio increased to a level higher that 1.0 aorta within 1 month for the V-II and 4 months for the ACG. In conclusion, the Bard ACG has demonstrated excellent biocompatibility in terms of blood T cell behaviour and acid phosphatase activity at the implant site. Finally, its healing response is equivalent to that of the uncoated Dacron prosthesis once the albumin coating has been resorbed.

Acid Phosphatase↗
PubMed1995

Carbodiimide cross-linked gelatin: a new coating for porous polyester arterial prostheses.

The performance of a polyester arterial prosthesis impregnated with gelatin and cross-linked with carbodiimide (Uni-graft) was compared with its porous parent graft (Protegraft) using a canine thoraco-abdominal bypass model. The grafts were investigated in terms of their handling characteristics, imperviousness at implantation, surface thrombogenicity and healing behaviour. Prostheses 30 cm in length were implanted for the following periods: 4, 24 and 48 h, 1, 2 and 4 weeks, 2, 3, 4, 5 and 6 months. Both types of graft had good handling characteristics. The ready-to-use impregnated graft provided satisfactory haemostasis at implantation with no blood permeating through the wall after flow was restored. Both grafts exhibited low surface thrombogenicity, as determined by the uptake of labelled fibrin and platelets, and the healing sequence of the impregnated graft after resorption of the gelatin was equivalent to that of the preclotted control. Biodegradation of the gelatin was complete within 1 month of implantation with the subsequent development of a collagenous internal capsule at both anastomoses. Endothelial cells were observed between 4 and 6 months, but were confined to small islets distributed along the luminal surface. The prostacyclin/thromboxane A2 (PGI2/TXA2) ratio, which gives an indication of the level of endothelial cell activity, was greater than 1.0 after 1 week of implantation for the control graft. For the impregnated graft it reached 1.0 only after 3 months of implantation, but remained above 1.0 for periods of up to 6 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1995

Late complication of a Greenfield filter associating caudal migration and perforation of the abdominal aorta by a ruptured strut.

We report the case of a 67-year-old woman who was admitted for surgical removal of a Greenfield filter that had been inserted 7 years before because of recurrent deep vein thrombosis associated with pulmonary embolism. This complication appeared on a plain abdominal radiogram that showed a 7 cm distal migration of the filter, a 30-degree angulation, and rupture of a strut at the level of the hub. Computed tomography, aortography, and ascending cavography demonstrated that the inferior vena cava was perforated by the struts and that the ruptured strut had penetrated the infrarenal aorta. As demonstrated by scanning electron microscopy, the fracture was due to a structural defect of the strut at its insertion point within the hub, with no sign of corrosion. Energy-dispersive radiography analysis failed to demonstrate impurity in the metal composition.

Aged↗
PubMed1993

Expanded polytetrafluoroethylene arterial prostheses in humans: histopathological study of 298 surgically excised grafts.

The expanded polytetrafluoroethylene vascular prosthesis is considered to be the best synthetic alternative for peripheral arterial reconstruction. Most studies on the healing characteristics of expanded polytetrafluoroethylene prostheses have been carried out on animals, and very few data are available on prosthesis implanted in humans long term. We implanted 298 expanded polytetrafluoroethylene grafts as arterial substitutes in humans. The mean duration of implantation was 523 d and the grafts were implanted mainly for infrainguinal or axillofemoral bypass. The cellular and collagen infiltration of the microporous expanded polytetrafluoroethylene structure was generally poor. Infiltration occurred mainly in the external region of the prosthetic wall and increased with the duration of implantation. The external reinforcement was not a major factor in limiting tissue infiltration. The luminal surfaces were covered with a thin, irregular layer of organized fibrin, interspersed with exposed expanded polytetrafluoroethylene areas. Mineral deposits were observed in five cases. Despite poor healing, the clinical performance of expanded polytetrafluoroethylene vascular prostheses is relatively good. Since the chief advantage of this material is good mechanical stability in vivo, any modifications of the graft to improve healing characteristics or thrombogenic properties should not be made at the expense of stability in vivo.

Adult↗
PubMed1993

Expanded polytetrafluoroethylene arterial prostheses in humans: chemical analysis of 79 explanted specimens.

The expanded polytetrafluoroethylene (ePTFE) vascular prostheses are widely used as small and medium diameter blood conduits when an autologous venous material is not available or is not suitable. The long-term performance of a prosthesis is dependent on several factors, including its healing characteristics and its stability in vivo. This study was undertaken to assess whether chemical degradation of ePTFE occurs when such arterial substitutes are implanted in humans. Seventy-nine ePTFE grafts excised for complications were analysed using the following techniques: measurement of the contact angle (theta), electron spectroscopy for chemical analysis (ESCA or XPS), Fourier transform infra-red spectroscopy (FTIR) and differential scanning calorimetry (DSC). The results were compared with those obtained from virgin ePTFE and virgin ePTFE washed prostheses. The measurement of the contact angle (theta) permits the comparison of the level of hydrophobicity of material after in vivo residency. The contact angles of explanted ePTFE grafts are greater than those of virgin ones but remain close to those of washed virgin prostheses. The ESCA method allowed investigation of the chemical changes which occur on the surface of ePTFE prostheses after implantation because of the low penetration of the X-ray (about 50 A). This study did not reveal any chemical degradation of the ePTFE with time of implantation for periods up to 6.5 yr. Changes in the surface composition were probably related to lipid and/or protein uptake. The FTIR spectroscopy provides information about the chemical composition of material. Compared with the virgin ePTFE prostheses, the FTIR spectra of explanted prostheses showed specific bands which are characteristic of lipid and/or protein absorptions. The bulk properties of ePTFE studied by DSC did not show any significant changes with time of implantation. It is concluded that ePTFE grafts remain stable in vivo for periods up to 6.5 yr.

Biocompatible Materials↗
PubMedDate not supplied

Can collagen impregnated polyester arterial prostheses be recommended as small diameter blood conduits?

A collagen impregnated graft and its parent preclotted prosthesis were implanted as thoraco-abdominal bypasses in dogs for periods ranging from 4 hr to 6 months and evaluated for their ease of handling, imperviousness, and healing behavior in terms of luminal surface thrombogenicity using labeled platelets and fibrinogen, prostacyclin (PGI2) secretion, histomorphometric determination of internal capsule thickness, and histopathologic and scanning electron microscopic studies. The collagen impregnated graft was impervious to blood and both grafts showed excellent handling characteristics. Fibrin uptake was negligible on both grafts; however, platelet uptake was higher on the collagen impregnated graft than on the control graft at 4 and 24 hr. The healing behavior of the collagen impregnated graft was also found to be different than that of the control graft between 1 and 6 months post implantation. The development of a host collagenous internal capsule at the anastomoses, and a confluent endothelial lining, was observed in both grafts at 1 month; in later implantation periods, the healing of the medial region was found to be more irregular in the collagen impregnated grafts, showing a lower mean PGI2 secretion than the preclotted control grafts. Histomorphometric analysis showed the internal capsule on the collagen impregnated grafts to be thicker than on the control grafts for most periods of implantation. The current study illustrates that the healing process of collagen impregnated grafts is delayed and that bovine collagen has a stimulating effect on tissue encapsulation. Current impregnated polyester arterial prostheses therefore cannot be recommended as small diameter blood conduits.

Animals↗