sigma(54) Promoters control expression of genes encoding the hook and basal body complex in Rhodobacter sphaeroides

Gene expression of the flagellar system is tightly controlled by external stimuli or intracellular signals. A general picture of this regulation has been obtained from studies of Salmonella enterica serovar Typhimurium. However, these regulatory mechanisms do not apply to all bacterial groups. In this study, we have investigated regulation of the flagellar genetic system in Rhodobacter sphaeroides. Deletion analysis, site-directed mutagenesis, and 5'-end mapping were conducted in order to identify the fliO promoter. Our results indicate that this promoter is recognized by the factor sigma(54). Additionally, 5'-end mapping of the flgB and fliK transcripts suggests that these mRNAs are also transcribed from sigma(54) promoters. Finally, we showed evidence that suggests that fliC transcription is not entirely dependent on the presence of a complete basal body-hook structure. Our results are discussed in the context of a possible regulatory hierarchy controlling flagellar gene expression in R. sphaeroides.

Assessment of systematic use of intraoperative transesophageal echocardiography during cardiac surgery in adults: a prospective study of 203 patients

OBJECTIVE

To determine the usefulness of systematic intraoperative transesophageal echocardiography in a cardiac surgical unit.

DESIGN

Open prospective observational survey.

SETTING

University Hospital.

PARTICIPANTS

Consecutive adult patients (n = 203) undergoing elective or urgent cardiac operations.

MEASUREMENTS AND MAIN RESULTS

Pre-cardiopulmonary bypass imaging yielded unsuspected findings in 26 patients (12.8%) and changed the planned surgery in 22 patients (10.8%). Transesophageal echocardiography modified the diagnosis in eight patients (17%) operated on for mitral valvulopathy, in seven patients (15.5%) with aortic valvular disease, in four patients (4.6%) with coronary artery disease, in five patients operated on for thoracic aorta diseases regardless of their localization (18.5%), and in two miscellaneous cases. On the basis of the data obtained from the transesophageal echocardiography carried out at the end of cardiopulmonary bypass, an immediate reintervention was required in five cases (2.5%).

CONCLUSIONS

It is concluded that systematic intraoperative transesophageal echocardiography significantly affected decision making in this cardiac surgical unit. Its routine use in all cardiac surgical patients is recommended.

Long term results of mitral valve repair: posterior papillary muscle repositioning versus chordal shortening

OBJECTIVE

Mitral valve repair is considered as the gold standard to treat mitral regurgitation. However anterior leaflet prolapse in the posterior paramedial and paracommissural area remains a challenging problem. Indeed several elongated chordae may arise from a single posterior papillary muscle head which does not allow safe separate chordal shortening (CS). We therefore suggest use of papillary muscle repositioning in such cases.

METHODS

In a cohort of 180 mitral valve repair performed between 1989 and May 1998, we have retrospectively studied 100 consecutive patients who underwent anterior leaflet repair in the posterior paramedial and paracommissural area. Group I (n = 60) had posterior papillary muscle repositioning (PPMR) and group II (n = 40) had CS. There was no statistical difference between the two groups concerning age, functional class and left ventricular function. Etiology was similar in both groups, degenerative process being predominant. At echocardiogram, regurgitation was graded 3.4/4 in both groups. There was no statistical difference concerning preoperative ejection fraction, end systolic and end diastolic left ventricular diameter.

RESULTS

There were no in-hospital deaths in group I and two deaths in group II not related to mitral valve repair. Mean follow up is 26.4 +/- 24.2 months in group I and 46.1 +/- 28.8 months in group II. No patient was lost to follow up. Severe mitral regurgitation was not observed. Mean regurgitation at follow up was 0.8 +/- 0.7 in group I and 0.8 +/- 0.8 in group II (P = n.s.); there was no statistical difference between the two groups concerning postoperative ejection fraction, end systolic and end diastolic left ventricular diameter. There was no late cardiac death in either group and there were no thromboembolic events. Actuarial survival rate is 100% and 94.4% in group I and 92% and 84.4% in group II at 2 and 6 years, respectively.

CONCLUSION

This experience shows that PPMR provides as good longterm results as CS to repair anterior leaflet prolapse in posterior paramedial and paracommissural area with lesser morbidity and mortality.

Interaction of FliI, a component of the flagellar export apparatus, with flagellin and hook protein

FliI is a key component of the flagellar export apparatus in Salmonella typhimurium. It catalyzes the hydrolysis of ATP which is necessary for flagellar assembly. Affinity blotting experiments showed that purified flagellin and hook protein, two flagellar axial proteins, interact specifically with FliI. The interaction of either of the two proteins with FliI, increases the intrinsic ATPase activity. The presence of either flagellin or hook protein stimulates ATPase activity in a specific and reversible manner. A Vmax of 0.12 nmol Pi min-1 microgram-1 and a Km for MgATP of 0.35 mM was determined for the unstimulated FliI; the presence of flagellin increased the Vmax to 0.35 nmol Pi min-1 microgram-1 and the Km for MgATP to 1.1 mM. The stimulation induced by the axial proteins was fully reversible suggesting a direct link between the catalytic activity of FliI and the export process.

Cardiac metaiodobenzylguanidine uptake in patients with moderate chronic heart failure: relationship with peak oxygen uptake and prognosis

OBJECTIVES

This prospective study was undertaken to correlate early and late metaiodobenzylguanidine (MIBG) cardiac uptake with cardiac hemodynamics and exercise capacity in patients with heart failure and to compare their prognostic values with that of peak oxygen uptake (VO2).

BACKGROUND

The cardiac fixation of MIBG reflects presynaptic uptake and is reduced in heart failure. Whether it is related to exercise capacity and has better prognostic value than peak VO2 is unknown.

METHODS

Ninety-three patients with heart failure (ejection fraction <45%) were studied with planar MIBG imaging, cardiopulmonary exercise tests and hemodynamics (n = 44). Early (20 min) and late (4 h) MIBG acquisition, as well as their ratio (washout, WO) were determined. Prognostic value was assessed by survival curves (Kaplan-Meier method) and uni- and multivariate Cox analyses.

RESULTS

Late cardiac MIBG uptake was reduced (131+/-20%, normal values 192+/-42%) and correlated with ejection fraction (r = 0.49), cardiac index (r = 0.40) and pulmonary wedge pressure (r = -0.35). There was a significant correlation between peak VO2 and MIBG uptake (r = 0.41, p < 0.0001). With a mean follow-up of 10+/-8 months, both late MIBG uptake (p = 0.04) and peak VO2 (p < 0.0001) were predictive of death or heart transplantation, but only peak VO2 emerged by multivariate analysis. Neither early MIBG uptake nor WO yielded significant insights beyond those provided by late MIBG uptake.

CONCLUSIONS

Metaiodobenzylguanidine uptake has prognostic value in patients with wide ranges of heart failure, but peak VO2 remains the most powerful prognostic index.

[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.

[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.

[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.

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.

Toward a principled methodology for neural network design and performance evaluation in QSAR. Application to the prediction of logP

The prediction of properties of molecules from their structure (QSAR) is basically a nonlinear regression problem. Neural networks are proven to be parsimonious universal approximators of nonlinear functions; therefore, they are excellent candidates for performing the nonlinear regression tasks involved in QSAR. However, their full potential can be exploited only in the framework of a rigorous approach. In the present paper, we describe a principled methodology for designing neural networks for QSAR and estimating their performances, and we apply this approach to the prediction of logP. We compare our results to those obtained on the same molecules by other methods.

[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.

[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.

[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.

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.

[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.

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.

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.

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.

The proper use of glue: a 20-year experience with the GRF glue in acute aortic dissection

BACKGROUND

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 analyzes the late results obtained with this adjunct in an experience extending over a twenty-year period of time.

PATIENTS AND METHODS

From January 1977 to March 1996, 171 patients (124 males and 47 females) aged from 15-79 years (mean age: 53 +/- 14 years) underwent an emergency operation for type A aortic dissection in our institution. All patients suffered from acute type A dissection and 144 (84%) were operated on within 48 hours after the onset of symptoms. Twenty-six patients (15.2%) had Marfan's syndrome. The ascending aorta was replaced in all patients and the aortic stumps were reinforced with the GRF glue. In 39 patients (23%), the aortic valve was replaced either independently (5 cases, 3%) or by means of a composite graft (34 cases, 19.8%). Because of the location of the intimal tear, the aortic replacement was extended to the transverse arch in 58 patients (33.9%).

RESULTS

Hospital mortality amounts to 21% (36 patients), 22.8% in patients with arch replacement and 21.1% in patients without arch replacement (n.s). One hundred thirty-five patients were discharged and surveyed from 2 months to 19 years postoperatively (cumulative follow-up: 856 patients/years. Mean follow-up: 79 +/- 66 months). During this period of time, 22 patients (16.1%) had to be reoperated on for a total of 28 reoperations. Six of those (27.2%) 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 thoracoabdominal replacement (p < 0.04) were determinant risk factors of death at reoperation. The acturial freedom from reoperation (Kaplan-Meier, CI: 95%) is: 96.08% (90.9-98.2), 87.6% (79.8-92.7), 80.9% (70.8-86.1), 66.4% (51.1-78.9) at 1, 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 (K-M. C.I.: 95%), including hospital mortality, is: 71.5% (64.3-77.8), 66% (58.3-73), 56.4% (47.7-64.7), 46.3% (36.4-56.5) at 1, 10 and 15 years.

CONCLUSIONS

The GRF glue has proved to be extremely useful during emergency initial 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.