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G Dreyfus

Publications and source records attributed to G Dreyfus.

At least 37 records · Page 2Linked to original sources
PubMed1998

[Surgical treatment of acute dissection of the ascending aorta (20 years experience)].

PURPOSE: In 1977, the use of gelatine-resorcine-formaline (GRF) biological glue during surgery of acute type A aortic dissection was proposed. The present study retrospectively analyses the late results obtained with this adjunct in an experience extending over a 20-year period. PATIENTS AND METHODS: From January 1977 to July 1997, 193 patients (139 males and 54 females) aged from 15 to 79 years (mean age: 53 +/- 14 years) underwent an emergency operation for type A aortic dissection in our institution. All patients suffering from acute type A dissection and 162 (84%) were operated on within 48 hours after the onset of symptoms. Twenty-eight patients (15.2%) had Marfan's syndrome. In all patients the ascending aorta was replaced and the aortic stumps were reinforced with the GRF glue. In 43 patients (22.2%), the aortic valve was replaced either independently (5 cases-2.5%) or by means of a composite graft (35 cases-19.5%). Recently three patients underwent a complete replacement of the ascending aorta and coronary reimplantation with preservation of the native aortic valve. Because of the location of the intimal tear, the aortic replacement was extended to the transverse arch in 58 patients (30%). RESULTS: Hospital mortality amounted to 21% (40 patients) (22.8% in patients with arch replacement and 20.3% in patients without arch replacement) (ns). The survivors were surveyed from 2 months to 20 years post-operatively (cumulative follow-up: 856 pt/years, mean follow-up: 85 +/- 66 months). During this period of time, 23 patients (15%) had to be reoperated on for a total of 29 procedures. Six of those patients (26%) died at reoperation. At univariate analysis, presence of Marfan's syndrome (P < 0.05) and absence of arch replacement (P < 0.02) were determinant risk factors for reoperation. Emergency (P < 0.01) and thoraco-abdominal replacement (P < 0.04) were determinant risk-factors of death at reoperation. The actuarial freedom from reoperation (Kaplan-Meier, CI: 95%) was: 96.5% (90.9-98.2), 87.6% (79.8-92.7), 80.9% (70.8-88.1), 66.4% (51.1-78.9) at one, 5, 10 and 15 years, respectively. A total of 36 patients (27.7%) died during follow-up. Presence of Marfan's syndrome (P < 0.01), reoperation (P < 0.02), stroke (P < 0.05), cardiac failure (P < 0.05) were determinant risk factors of late mortality. The actuarial late survival rate (Kaplan-Meier. CI: 95%), including hospital mortality, was: 71.5% (64.3-77.8), 66% (58.3-73), 56.4% (47.7-64.7), 46.3% (36.4-56.5) at one, 5, 10 and 15 years. CONCLUSION: The GRF glue has proved to be extremely useful during initial emergency surgery for acute type A dissection, making the procedure much easier and safer. Through this operative improvement, the use of the GRF glue seems to have a beneficial influence on the late results which, however, depend mainly on the patient's basic condition.

Adolescent↗
PubMed1998

The flagellar switch genes fliM and fliN of Rhodobacter sphaeroides are contained in a large flagellar gene cluster.

In this work, the genes that encode the FliM and FliN proteins of Rhodobacter sphaeroides were characterized. These genes are part of a large flagellar gene cluster in which six additional open reading frames encoding products homologous to FliL, FliO, FliP, FliQ, FliR, and FlhB proteins from other bacteria were identified. The inactivation of the fliM gene gave a nonflagellate phenotype (Fla-), suggesting that FliM is required for flagellar assembly. Complementation analysis of this fliM mutant indicated that fliM and fliN transcription starts beyond the 5' end of fliK and terminates after fliN.

Amino Acid Sequence↗
PubMed1998

[Mitral valvuloplasty for asymptomatic or pauci-symptomatic mitral insufficiency].

The aim of this study was to assess the results of mitral valvuloplasty for chronic asymptomatic or paucisymptomatic mitral regurgitation. Of 584 patients operated for chronic mitral regurgitation between January 1989 and December 1994, 175 were in NYHA Classes I and II and made up the study population. All had chronic grade 3 or 4/4 mitral regurgitation suitable for mitral valvuloplasty. The average follow-up was 34.3 months. Mitral valvuloplasty was performed in 174 patients, the other patient requiring mitral valve replacement. Three patients died (1.7%) and the actuarial 5 year survival was 98.2 +/- 1.0%. The probability of absence of reoperation and absence of thrombo-embolic complications at 5 years were 97 +/- 0.8% and 96.3 +/- 1.7% respectively. The residual regurgitation at Doppler echocardiography was minimal or absent in 94% of patients at the last follow-up control. The mean end-systolic and end-diastolic left ventricular dimensions decreased from 40.0 +/- 6.8 mm and 64.8 +/- 7.0 mm before surgery to 34.6 +/- 6.7 mm (p < 0.001) and 52.7 +/- 7.4 mm (p < 0.001) at the last control. The authors conclude that conservative mitral valve surgery for NYHA Classes I and II patients with chronic mitral regurgitation is feasible with a low risk and is associated with a significant reduction in ventricular volumes and stability of valvular continence at medium-term. When performed by teams trained in techniques of mitral valvuloplasty, these results suggest that surgery should be performed early.

Actuarial Analysis↗
PubMed1998

[A prospective comparative study of coronary angiography and endocoronary ultrasonography in the detection of coronary lesions after cardiac transplantation].

Coronary angiography is the reference method for the detection of coronary disease of the cardiac grafts which threatens the long-term prognosis of cardiac transplantation. The primary results of treatment for slowing, stabilising or even improving coronary transplant disease are encouraging and make necessary the development and evaluation of reliable diagnostic methods. The authors undertook a prospective study of 48 asymptomatic patients with normal graft wall motion between January 1995 and March 1997 to compare the results of coronary angiography and endocoronary ultrasonography. The patients had been transplanted in the 10 years preceding the study. The results of the two methods were concordant in 33 cases (69%) (NS), for the confirmation (9 cases) or the information of coronary transplant disease (24 cases). The results were contradictory in 15 cases (31%): in 12 cases, endocoronary ultrasonography showed signs of coronary disease whereas the coronary angiography was estimated to be normal: in the remaining 3 cases, coronary angiography was abnormal but no signs of coronary disease were found on endocoronary ultrasonography. The specificity of coronary angiographic detection was 89% and therefore very satisfactory, but its sensitivity (43%) was poor. In addition, endocoronary ultrasonography allows analysis of the extension of coronary lesions to unstenosed segments, the quantification of intimal thickening. Therefore, endocoronary ultrasonography should become the reference investigation for coronary disease of cardiac transplants.

Adult↗
PubMed1998

[Alternative surgical options to heart transplantation].

Cardiac transplantation is the treatment of reference for refractory cardiac failure but the limited number of donors, the complications inherent to transplantation and the relative and absolute contra-indications has made it necessary to find alternative surgical solutions. The detection of myocardial viability by Thallium scintigraphy, Dobutamine echocardiography and/or position emission tomography in coronary disease, allows identification of zones which are capable of recovering contractile function after revascularisation. The authors report the results of a series of 91 operated patients with a 10 year follow-up having a 72% 5 year actuarial survival and improved ejection fraction. The other alternative which may improve symptoms and prognosis in patients with severe ischaemic heart disease with left ventricular dysfunction is apical remodelling or Dor's procedure. The results of a haemodynamic study at 1 year of 171 patients clearly show a functional improvement and an increase of the ejection fraction. The advantage of this method is that it can be used in patients with dyskinetic and akinetic plaques resulting from antero-septo-apical infarction. Finally, even if mitral regurgitation is relatively uncommon in chronic ischaemic heart disease, a simple procedure (annuloplasty) is often sufficient to correct the mitral regurgitation and reduce the afterload of a failing ventricle. On the other hand, in dilated cardiomyopathy, two new options have been developed; one, suggested by Steven Bolling, proposes simple mitral annuloplasty whatever the underlying cause (primary or ischaemic cardiomyopathy) with symptomatic improvement and better haemodynamics in terms of increased cardiac output and oxygen consumption on exercise and an actuarial survival much higher than that of cardiac transplantation at one and at two years. The most recent innovation is the Batista procedure which is a method of ventricular reduction associated with correction of mitral regurgitation. The authors have assessed 20 patients for this operation at the Foch Hospital by Dobutamine echocardiography and 5 patients underwent the procedure. All 5 patients reported symptomatic improvement but some had an unchanged haemodynamic status. Others improved at rest and some improved on exercise. The Cleveland Clinic series reported results in 57 cases. Whichever alternative method tested, there is a significant functional improvement but the cardiac output does not always increase. There are no comparative prospective randomised studies and strict selection of patients is required, a problem not yet resolved for all indications. The advantages of these procedures are certain as there is no waiting list, the functional results in good indications have been demonstrated and, if necessary, secondary orthotopic cardiac transplantation is always possible.

Aged↗
PubMed1998

[Mesenteric arterial thrombosis in protein S deficiency].

Arterial thrombosis is very rarely described in patients with coagulation factors deficiency. We report the first case of superior mesenteric artery thrombosis of a normal mesenteric artery associated with protein S deficiency, causing massive mesenteric infarction with short bowel syndrome. Eight-month parenteral nutrition and definitive antivitamin K anticoagulation were required in this 72 year-old patient. The initial oral anticoagulant malabsorption disappeared a few months later as clinical and biological course improved. Rapid intestinal adaptation was probably consecutive to early enteral refeeding. The possibility of reintroducing antivitamin K despite initial inefficacy should be stressed, as well as the necessity of an exhaustive coagulation work-up in patients with mesenteric infarction.

Aged↗
PubMed1998

[Giant cell myocarditis. Report of a case].

The authors report a case of giant cell myocarditis leading to rapidly progressive cardiac failure despite immuno-suppressor treatment in a 20 year old woman. The cardiac failure was successfully managed by implantation of a left ventricular assist device and then cardiac transplantation. The problems encountered underline the importance of accurate diagnosis by endomyocardial biopsy before undertaking treatment and the difficulties in the choice of appropriate method of assistance in this indication. Giant cell myocarditis is a rare cause of cardiac failure and should be considered in the differential diagnosis in view of its clinical features and risk of progression. The literature and the therapeutic implications are discussed.

Adult↗
PubMed1997

Isolation and ultrastructural study of the flagellar basal body complex from Rhodobacter sphaeroides WS8 (wild type) and a polyhook mutant PG.

Filament-Hook-Basal Body (FHBB) complexes were isolated from the purple non-sulphur facultative anaerobic bacterium Rhodobacter sphaeroides (WS8) by lysozyme digestion of the cells followed by an alkaline treatment and ultracentrifugation, and they were analysed by electron microscopy. The structure is composed of a filament linked through an enlarged junction to the hook and a basal body composed of L and P rings, a rod, and a less well-defined cytoplasmic ring that has evidence of additional attached structures. Hook-basal body complexes isolated from a mutant (PG) which produces an extended hook but no filament shows basal body structures identical to those of wild-type FHBBs.

Bacterial Proteins↗
PubMed1997

Characterization of the alpha and beta-subunits of the F0F1-ATPase from the alga Polytomella spp., a colorless relative of Chlamydomonas reinhardtii.

The isolation and partial characterization of the oligomycin-sensitive F0F1-ATP synthase/ATPase from the colorless alga Polytomella spp. is described. Purification was performed by solubilization with dodecyl-beta-D-maltoside followed by Sepharose Hexyl ammonium chromatography, a matrix that interacts with the F1 sector of mitochondrial ATPases. The alpha-subunit, which migrates on SDS-polyacrylamide gels with an apparent molecular mass of 55 kDa, was identified by the N-terminal sequencing of 47 residues. This subunit exhibited a short extension at its N-terminus highly similar to the one described for the unicellular alga Chlamydomonas reinhardtii (Nurani, G. and Franzén L.-G. (1996) Plant Mol. Biol. 31, 1105-1116). In whole mitochondria, the alpha-subunit was susceptible to limited proteolytic digestion induced by heat. An endogenous protease removed the first 22 residues of the mature alpha-subunit. Subunit beta was also identified by N-terminal sequencing of 31 residues. This subunit of 63 kDa exhibited a higher apparent molecular mass than alpha, as judged by its mobility on denaturing polyacrylamide gel electrophoresis. This beta-subunit is 7-8 kDa larger than the beta-subunits of other mitochondrial ATPases. It is suggested that the beta-subunit from Polytomella spp. may have a C-terminal extension similar to that described for the green alga C. reinhardtii (Franzén, L.-G. and Falk, G.(1992) Plant Mol. Biol. 19, 771-780). In addition, it was found that the C-terminal extension of the beta-subunit of C. reinhardtii showed homology with the endogenous ATPase inhibitors from various sources and with the epsilon-subunit from the F0F1-ATP synthase from Escherichia coli, which is considered to be a functional homolog of the inhibitor proteins. The data reported here provide the first biochemical evidence for a close relationship between the colorless alga Polytomella spp. and its photosynthetic counterpart C. reinhardtii. It is also suggested that the C-terminal extensions of the beta-subunits of the ATP synthases from these algae, may play a regulatory role in these enzymes.

Amino Acid Sequence↗
PubMed1997

Structural and genetic analysis of a mutant of Rhodobacter sphaeroides WS8 deficient in hook length control.

Motility in the photosynthetic bacterium Rhodobacter sphaeroides is achieved by the unidirectional rotation of a single subpolar flagellum. In this study, transposon mutagenesis was used to obtain nonmotile flagellar mutants from this bacterium. We report here the isolation and characterization of a mutant that shows a polyhook phenotype. Morphological characterization of the mutant was done by electron microscopy. Polyhooks were obtained by shearing and were used to purify the hook protein monomer (FlgE). The apparent molecular mass of the hook protein was 50 kDa. N-terminal amino acid sequencing and comparisons with the hook proteins of other flagellated bacteria indicated that the Rhodobacter hook protein has consensus sequences common to axial flagellar components. A 25-kb fragment from an R. sphaeroides WS8 cosmid library restored wild-type flagellation and motility to the mutant. Using DNA adjacent to the inserted transposon as a probe, we identified a 4.6-kb SalI restriction fragment that contained the gene responsible for the polyhook phenotype. Nucleotide sequence analysis of this region revealed an open reading frame with a deduced amino acid sequence that was 23.4% identical to that of FliK of Salmonella typhimurium, the polypeptide responsible for hook length control in that enteric bacterium. The relevance of a gene homologous to fliK in the uniflagellated bacterium R. sphaeroides is discussed.

Amino Acid Sequence↗
PubMed1997

Significance of serum immunoglobulin M to hepatitis C virus core in patients with chronic hepatitis C.

OBJECTIVES: Anti-hepatitis C virus (HCV) IgM antibodies were found in patients with both acute and chronic hepatitis C. The aims of this study were to determine the significance, in terms of liver disease, virological parameters, and response to interferon therapy, of IgM antibody to hepatitis C virus core protein (IgM anti-HCV-core) in the serum of patients with chronic hepatitis C. METHODS: The presence of IgM anti-HCVcore was investigated in 42 patients with chronic hepatitis C. Tests for IgM anti-HCVcore was carried out before interferon therapy. The patients received 3 MU of interferon-alpha three times weekly for 6 months. A response to interferon therapy was defined as normal transaminase activity and negative viremia at the end of treatment (month 6: response), and a sustained response was defined as normal ALT values and negative viremia for 6 months after completion of therapy. RESULTS: Sixteen patients (38%) displayed IgM anti-HCVcore. The mean Knodell score of the IgM anti-HCVcore-positive patients was significantly higher than that of the IgM anti-HCVcore-negative patients (11.5 +/- 3.4 vs. 9.1 +/- 3.1, p = 0.04), and the occurrence of IgM anti-HCVcore tended to be associated with serotype 1 virus (p = 0.08). Finally, a significantly higher percentage of responders to interferon at the end of therapy were IgM anti-HCVcore negative (p = 0.04), and only one patient with a ratio of sample to cutoff over 2.0 responded to interferon. CONCLUSIONS: IgM anti-HCVcore appears to be a simple serological marker of more severe liver disease in patients with chronic hepatitis C and may have relevance to the outcome of antiviral therapy.

Antiviral Agents↗
PubMed1997

[Left ventricular reduction (Batista's technique). A new surgical option in dilated cardiomyopathy].

Cardiac transplantation remains the standard treatment for severe cardiomyopathy resistant to medical therapy. However, new techniques may help to put this off. Two patients with dilated cardiomyopathy were treated surgically since October 1996, one aged 48 and the other 52. They were in NYHA Class IV and one was dependent on inotropic drugs. Both had relative or absolute contra-indications to transplantation. The left ventricular end diastolic dimensions were over 70 mm with mild mitral regurgitation and fractional shortening of less than 12%. Coronary angiography was normal. They were operated in October 1996 and January 1997. The procedure consisted of correction of mitral regurgitation (annuloplasty) and of reduction of left ventricular volume by a triangular resection from the apese to the base of the heart. At histological examination, the resected myocardium measured 11 to 13 cm long and 5 to 7 cm at its base. The two patients were discharged from hospital after 45 and 30 days. There were no clinical signs of cardiac failure. Follow-up investigations showed a marked decrease in ventricular volumes, the end diastolic dimensions changing from 70 to 52 mm in the first, and from 76 to 54 mm in the second patient. The corresponding values of fractional shortening increased from 11 to 20% and from 6 to 17%. Left ventricular volumes decreased from 328 mL (end diastole) and 259 mL (end systole) to 140 mL and 74 mL in the first case, and from 300 mL (end diastole) and 280 mL (end systole) to 122 mL and 83 mL respectively in the second case. The ejection fraction increased from 20 to 40% and from 10 to 32%. These preliminary results show that the theoretical advantages of this surgical technique correspond to a practical reality. Larger series of patients are required to determine the optimal indications.

Cardiac Surgical Procedures↗
PubMed1996

Flagellar genes from Rhodobacter sphaeroides are homologous to genes of the fliF operon of Salmonella typhimurium and to the type-III secretion system.

A flagellar region of the genome of Rhodobacter sphaeroides was cloned and sequenced. Three ORFs were identified and arranged in the same order as fliH, fliI and fliJ of Salmonella typhimurium (St). ORF2 is highly similar to FliI from St (49% similarity) showing Walker's A and B motifs. Similar scores were found with proteins of the type-III secretion system of virulence factors. ORF3 shows 16.4 and 11.1% similarity to FliJ from St and Bacillus subtilis, respectively. This work also shows that ORF3 is similar to HrpJ5 from Pseudomonas syringae (19.2% similarity). It was found that ORF2 and ORF3 start immediately downstream from the adjacent coding region, suggesting a single transcriptional unit.

Amino Acid Sequence↗
PubMed1996

A Column Centrifugation Method for the Reconstitution in Liposomes of the Mitochondrial F0F1 ATP Synthase/ATPase

A method for reconstitution of membrane proteins into unilamellar liposomes is described. The model enzyme was the F0F1 ATP synthase from mitochondria when in complex or free from its inhibitor protein. The enzymes were first solubilized with either of two detergents, i.e., n-dodecyl-beta-D maltoside or lauryldimethylamine oxide. After solubilization, the enzymes were passed through a column of Sepharose-AH using an ADP/sodium cholate selective elution buffer. The enzymes recovered from the column were subsequently passed through a centrifuge column of Sephadex G-50 fine. The eluate contained liposomes in which the F0F1 complex (with and without inhibitor protein) had been reconstituted. The reconstituted enzymes were capable of hydrolyzing ATP with formation of electrochemical H+ gradients. They also catalyzed the ATP-Pi exchange reactions. Thus the F0F1 complex which is formed by 18 subunits can be rapidly reconstituted into liposomes in a fully functional state. Moreover the data show that the interactions between the enzyme and its inhibitor protein are not perturbed in the reconstitution procedure.

Journal Article↗
PubMed1996

Surgical treatment of asymptomatic and mildly symptomatic mitral regurgitation.

OBJECTIVE: The purpose of this study was to review the risk-benefit ratio of mitral valve repair in patients with severe mitral regurgitation and no or mild symptoms. METHODS: From January 1989 to December 1994, 584 patients were operated on for mitral regurgitation. Of these, 175 patients were in New York Heart Association class I or II with grade 3 to 4 isolated chronic mitral regurgitation. They comprise our study population. Mean age was 51.3 +/- 14.3 years. Principal causes of mitral regurgitation were degenerative in 128 (73%) and rheumatic in 26 patients (15%). Leaflet prolapse was the mechanism responsible for regurgitation in 152 patients (86%). Mitral valve repair was performed in 174 patients, and one patient required initial valve replacement. Mean follow-up was 34.3 +/- 18.8 months. RESULTS: Three patients died, for an overall mortality of 1.7%. Five patients were reoperated on, for an actuarial freedom from reoperation of 97.0% +/- 0.8% at 5 years. Actuarial freedom from thromboembolism and endocarditis was 96.3% +/- 1.7% and 99.4% +/- 0.6%, respectively, for an event-free survival of 91.0% +/- 2.0% at 5 years. Left atrial diameter decreased from 54.3 +/- 11.6 mm to 43.6 +/- 10.5 mm (p < 0.001). Left ventricular end-systolic and end-diastolic diameters decreased from 40.0 +/- 6.8 mm and 64.8 +/- 7.0 mm to 34.6 +/- 6.7 mm (p < 0.001) and 52.7 +/- 7.4 mm (p < 0.001), respectively. Mean residual mitral regurgitation was 0.44 +/- 0.6. CONCLUSION: Mitral valve repair for chronic mitral regurgitation in patients having mild or no symptoms was performed with low mortality and morbidity, good valve function, and preserved late left ventricular performance. Early repair may be advocated on the basis of severity of regurgitation and valve repairability, regardless of symptoms.

Adult↗
PubMed1996

Aortic root replacement with a composite graft. Factors influencing immediate and long-term results.

From April 73 to June 94, 203 patients (167 men, 36 women) aged from 10 to 74 years (mean: 44.8 +/- 15) underwent ascending aortic replacement with composite graft for: dystrophic aneurysm (AN) (130 cases, 64.5%), chronic dissection (CD) (35 cases, 17.2%), type A acute dissection (AD) (38 cases, 18.7%). Forty-six patients (22.6%) suffered from Marfan syndrome (24 AN, 13 AD, 9 CD). Thirty patients (14.7%) had undergone a previous cardiac or aortic operation. The ascending aortic replacement was extended to the transverse arch in 28 patients (13.7%). A mechanical valve was used in 193 cases (95%). Since 1986, the ascending aorta has been totally resected and a gelatin-or collagen-coated vascular prosthesis used. The technique of coronary reattachment has varied with time and according to the aortic lesions. The classic "Bentall" technique was used in 87 patients (43%), the "button" technique in 74 (36%), the "Cabrol" technique in 26 (13%) and a "mixed" technique in 16 cases (8%). The hospital mortality rate was 7.3% (15/203) (AN: 2.3%, CD: 11.4%, AD: 21%). The only predictors of hospital death were emergency AD (P < 0.03) and arch replacement (P < 0.02). Mean follow-up was 46 +/- 10 months (2-246). The overall long-term survival rate was (Kaplan Meier) 89 +/- 6% at 1 year, 77.9 +/- 9% at 5 years, 67.7 +/- 12% at 10 years and 61.3 +/- 15% at 12 years. The 10-year survival rate is significantly higher in patients with AN (77.8 +/- 11%) than in those with AD (61.6 +/- 17%) (log. rank: P < 0.01). The late survival rate is also significantly higher after the "button" or Bentall reimplantation than after the "Cabrol" or "mixed" methods (90 +/- 5% in the "button" group and 88.7 +/- 6%, 83.8 +/- 9% and 76.6 +/- 12% in the "Bentall" group vs 80 +/- 18%, 63 +/- 21% and 58 +/- 35% in the "Cabrol" group at 1, 5 and 8 years, respectively). In conclusion, ascending aortic replacement with a composite graft is a safe procedure especially when performed electively in patients with dystrophic aneurysm or Marfan syndrome. The technique of coronary reimplantation has a significant influence on the long-term results. The reimplantation of choice is the "button" technique, especially in the presence of a fragile aortic wall (AD). The "Cabrol" technique must be used when the "button" or the "Bentall" reimplantation is not feasible, for instance during redo procedures.

Adolescent↗
PubMed1996

Protection of the spinal cord during surgery of thoraco-abdominal aortic aneurysms.

OBJECTIVE: To assess the risk of ischemic cord injury, we have retrospectively studied the 115 patients who underwent a replacement of the thoracic descending or thoraco-abdominal aorta between January 1980 and December 1994. METHODS: In 72 patients the aortic lesion was located above the diaphragm. The aortic replacement was performed with the aid of extracorporeal circulation in all but 2 patients (97.2%). Only two cases of postoperative paraplegia were observed (2.7%). In 43 patients (10 females and 33 males aged from 26 to 69 years), the occurrence of postoperative paraplegia was considered as a major risk, because of the extension of the aortic lesions (Crawford types I, II and III). Twenty-six patients (60.4%) suffered from chronic dissection and 17 patients had atheromatous aneurysms. Sixteen patients (37.2%) had Marfan syndrome. Twelve patients (27.9%) had already undergone aortic replacement. A preoperative study of the spinal cord vascularization was carried out in 36 patients (83.6%) and the Adamkiewicz artery was visualized in 28 patients (77.8%). In 17 patients (39.5%, group I), the surgical procedure was performed without the aid of extracorporeal circulation. In the remaining 26 patients (60.5%, group II), the surgical procedure was carried out with the aid of cardiopulmonary bypass and profound hypothermic circulatory arrest. Sequential unclamping of the aorta was used in all patients. The cord vascularization was surgically restored in 32 patients (74.4%). When the Adamkiewicz artery was identified, the critical intercostal artery was reimplanted together with the two pairs of adjacent intercostal arteries (25 patients). When the origin of the Adamkiewicz artery remained unknown, the two or three most important patent pairs of intercostal arteries were reimplanted (7 patients). In 8 patients (18.6%) there were no patent intercostal arteries. RESULTS: Hospital mortality accounted for 37.2% (16 patients, including 5 patients with paraplegia). On univariate analysis, extension of the aortic lesions, emergency and redo surgery were the only significant risk factors of mortality (P = 0.05). Cord ischemia was observed in 9 patients (21%): permanent paraplegia in 7 patients (16.2%) and transient medullar disturbance in 2 patients (4.6%). The occurrence of paraplegia was reduced, though not significantly, in group II (16%) vs group I (29%) and in patients with preoperative assessment of the cord vascularization (18% vs 38%). CONCLUSIONS: In our experience: 1) The risk of paraplegia is related to the extension and the type of the aortic lesions. 2) The preoperative study of the medullar vascularization and the use of extracorporeal circulation with deep hypothermia and sequential aortic unclamping, reduce the risk of severe cord ischemia, and 3) Occurrence of postoperative paraplegia depends on several factors and cannot be totally prevented by the surgical technique.

Adult↗