[Reconstructive techniques for valvular heart disease].
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Angiography↗
Biomedical subjects
C Detter
Publications and source records attributed to C Detter.
Tracheal allograft transplantation in rats: the role of different immunosuppressants on preservation of respiratory epithelium.
BACKGROUND: Bronchiolitis obliterans is the most significant complication adversely affecting the survival of lung allograft recipients. Injury and loss of epithelium are associated with obliteration of the airway lumen. The aim of this study was to examine the effects of various immunosuppressants on airway epithelium. METHODS: Tracheae from Brown Norway donors were heterotopically transplanted into the greater omentum of Lewis (allografts) or Brown Norway (isografts) animals. Recipients were treated for 28 days with FK778 (20 mg/kg), tacrolimus (4 mg/kg), or sirolimus (2 mg/kg). Tracheal segments were evaluated for the degree of luminal occlusion as well as the type and percent of luminal epithelial cell coverage. RESULTS: All agents inhibited peritracheal infiltration and luminal obliteration. Tacrolimus- more than sirolimus-treated recipients showed partial preservation of the luminal epithelial coverage, whereas animals that received FK778 showed no respiratory epithelium. The epithelial loss was accompanied by the appearance of fibrous tissue, which replaced the mucosa. CONCLUSIONS: Tacrolimus as well as sirolimus effectively prevented the development of obliterative airway disease whereas tacrolimus and, to a lesser degree, sirolimus preserved epithelial cells as a source of protective cytokines. With FK778 significant airway obliteration was suppressed despite complete epithelial loss. Thus, FK778-treated animals displayed an epithelial-independent inhibitory effect on myofibroblast proliferation.
Animals↗
FK778: new cellular and molecular mechanisms of action.
PURPOSE: The new malononitrilamide FK778 is currently being evaluated as an immunosuppressant for organ transplantation. Its main mechanism is inhibition of a pivotal enzyme of pyrimidine biosynthesis. This report revealed new mechanisms of action on different cell types involved in acute and chronic allograft rejection. METHODS: Purified Brown-Norway rat aortic endothelial cell (EC) cultures were pretreated with several concentrations of FK778. Endothelial adhesion molecule expression (ICAM-1/VCAM-1) stimulated with TNF-alpha was quantified by immunofluorescence. Purified Lewis rat lymphocytes (LC) incubated with FK778 were stimulated via TCR/CD28 signals, and CD25 expression was quantified using FACS analysis. Uridine addition was used in all assays to reverse the pyrimidine synthesis blockade. Lymphocyte-EC interaction was assessed by micromanipulator-assisted single-cell adhesion assays. Finally, smooth muscle cell (SMC) proliferation and migration was analyzed. Uridine addition was used in all assays to reverse the pyrimidine synthesis blockade. RESULTS: TNF-alpha stimulation and TCR/CD28 co-stimulation significantly increased EC ICAM-1/VCAM-1-expression and LC CD25 surface expression, respectively. These effects were dose-dependently inhibited by FK778 and were not reversed by the addition of uridine. FK778 dose-dependently attenuated LC adhesion to allogeneic EC. The dose-dependent inhibition of SMC proliferation by FK778 was abolished by uridine addition, whereas the inhibitory effect on SMC migration was not affected by uridine supplementation. CONCLUSIONS: FK778 directly reduced endothelial adhesion molecule up-regulation, inhibited lymphocyte activation, and attenuated lymphocyte-endothelium interactions, critical early steps in graft rejection. These effects were separate from the blockade of pyrimidine synthesis. The antiproliferative potency of FK778 on SMC may be an important mechanism to inhibit the fibroproliferative lesions of chronic organ rejection.
Alkynes↗
[The ECG-gated 4-row multidetector CT of the heart in preoperative imaging minimal invasive coronary artery bypass grafting].
PURPOSE: Minimal invasive direct coronary artery bypass grafting (MIDCAB) or off-pump coronary artery bypass grafting (OPCAB) on the beating heart with full or mini-sternotomy are becoming more common in coronary bypass surgery of the left anterior descending (LAD). In the decision, which surgical approach (MIDCAB, OPCAB or conventional surgery with cardiopulmonary bypass) will be best used, knowledge of the anatomical field is of major importance. The aim of the study was to evaluate retrospective ECG-gated 4-row multidetector CT (MDCT) in patients planned for MIDCAB as additional imaging to coronary angiography. MATERIAL AND METHODS: The study included 25 consecutive patients. MSCT was performed as unenhanced (collimation 4 x 2.5 mm) and contrast-enhanced examination (140-170 ml, 300 mg Iodine/ml, collimation 4 x 1 mm). The evaluation included presence of LAD calcifications, distance of LAD and left internal mammarian artery (LIMA), course of LAD and LIMA, the presence or absence of bridging through myocardium or epicardial fat and the presence of pleural fibrosis. The MDCT results were correlated with intra-operative findings. RESULTS: All MDCTs could be assessed with reference to the demands. In 20/25 operations, MDCT had direct influence as to the selection of the surgical approach (11 MIDCAB, 7 OPCAB with mini-sternotomy and 5 with full sternotomy, 2 conventional surgeries). The distance of LAD and LIMA varied from 0.9 to 4.5 cm in MDCT. As to calcifications, 3/25 correlated patients had calcifications and 10 patients had no calcifications in the middle LAD. Seven patients had intraoperative fibrosis of the vessel wall without calcification of the middle LAD, which could not be detected with MDCT. Another 5 patients had single calcified plaques in the middle LAD, 4 of these had a fibrosis of the vessel and 1 had a normal vessel at surgery. In these cases, the anastomosis was done between the calcified plaques. No myocardial bridging was detected by MDCT and at surgery. Bridging of epicardial fat was shown by MDCT and at surgery in 9/25 patients and was excluded in 15 patients. In 1 patient, the LAD seemed to run superficially in MDCT, but was covered with fat as seen during surgery. The course of the LIMA was inconspicuous in all cases, no pleural fibrosis was found. CONCLUSIONS: The 4-row MDCT has proven to be adequate in addition to coronary angiography for preoperative evaluation in patients scheduled for MIDCAB and provides the surgeon with relevant information for the selection of the operative approach.
Aged↗
Midterm results and quality of life after minimally invasive vs. conventional aortic valve replacement.
BACKGROUND: This study compares early and mid-term results as well as the quality of life (QOL) between the minimally invasive and conventional aortic valve replacement (AVR). METHODS: Between 7/97 and 4/01, 70 patients (mean age 64.3 +/- 1.3 years) underwent minimally invasive AVR (group M) through an L-shaped ministernotomy. The results were compared to those of 70 conventional AVR (group C) patients during the same period. Patients were equally matched according to age, sex, ejection fraction, valvular lesion, and valve prosthesis. In groups M and C, follow-up was 98.5 % and 95.4 % complete and averaged 34.0 +/- 10.3 and 33.1 +/- 12.9 months, respectively. RESULTS: There were no hospital deaths in group M but two deaths in group C (p = n. s.). Conversion to full sternotomy was necessary in two group M patients. Cross-clamping time (71 +/- 15 min vs. 58 +/- 18 min), cardiopulmonary bypass time (105 +/- 22 min vs. 84 +/- 24 min), and time of surgery (228 +/- 45 min vs. 184 +/- 48 min) were significantly longer in group M. No statistically significant differences between the two groups for postoperative ventilation time, transfusion rate, ICU stay or length of hospital stay were recorded. At the end of follow-up, 98.5 % vs. 96.9 % of the patients were free of thromboembolism (p = n. s.), 100.0 % vs. 96.9 % were free of endocarditis (p = n. s.), and 98.5 % vs. 100.0 % were free of reoperation (p = n. s.) in group M compared to group C. Survival was 97.0 % vs. 91.9 % (p = ns). No differences in any of the 8 QOL categories, in patient satisfaction with the operative result or in judgment of the cosmetic aspect were noted among groups. CONCLUSIONS: This study has failed to show any advantage of minimally invasive AVR in early or midterm follow-up.
Adult↗
Indirect coronary angiography: a feasibility study.
The diagnostic method of choice to proof coronary artery disease and to localize stenoses and to judge the stage of the disease is coronary angiography. A new angiographic technique invented by. Wolffgram and Krieter that works without cannulation of the coronary arteries could simplify the interventional procedure. In addition, a technique like this could be used for angiography after CABG surgery directly on the table for quality assurance reasons. This angiography could be performed by the cardiac surgeon without necessarily involving a cardiologist. A feasibility study was successfully done in a cooperation of the Departments. for Cardiology and Cardiac Surgery, Munich University, Steinbeis Transfer Centre for rHealthcare Technologies, Tuebingen and Fraunhofer Technology Development Group (TEG), Stuttgart.
Animals↗
Aortic valvotomy for congenital valvular aortic stenosis: a 37-year experience.
BACKGROUND: The purpose of the study was to analyze the long-term results of aortic valvotomy and the risk factors associated with reoperation and survival. METHODS: From 1960 to 1977, 116 patients with congenital valvular aortic stenosis underwent isolated aortic valvotomy at a mean age of 13.7 +/- 7.8 years with a mean aortic gradient of 78 +/- 33 mm Hg. Fifteen patients had additional aortic regurgitation, and leaflet calcification was present in another 15 patients. RESULTS: Postoperatively the mean aortic gradient decreased to 19.4 +/- 11.3 mm Hg (p < 0.0001). Early mortality was 2.6%. At a mean follow-up of 23.8 years, 26 late deaths (22.4%) occurred among the 113 early survivors. Actuarial 10-, 20-, 30-, and 37-year survival rates were 94.6%, 79.7%, 76.2%, and 72.5%, respectively. According to multivariate Cox regression analysis, survival was influenced by preoperative New York Heart Association class (p = 0.0418), leaflet calcification (p = 0.0339), date of operation (p = 0.0253), and postoperative endocarditis (p < 0.0001). At a mean interval of 18.3 years, 37 patients required reoperation (31.9%) mainly because of recurrent aortic stenosis. The reoperation rate increased significantly 15 years postoperatively from 0.73%/year to 2.31%/ year (p < 0.0001). In a multivariate risk model, reoperation was influenced by older patient age (p = 0.0032) and the presence of leaflet calcification (p = 0.0289). CONCLUSIONS: AORTIC valvotomy is a simple and effective procedure for congenital aortic stenosis with excellent long-term results. However, the rate of reoperation increases 15 years postoperatively, and clinical follow-up should be intensified. Our results suggest that early repair should be performed and that adequate patient selection is the most important determinant of the longterm results.
Actuarial Analysis↗
Single vessel revascularization with beating heart techniques -- minithoracotomy or sternotomy?
OBJECTIVE: The purpose of the study was to evaluate the best surgical approach in off-pump single vessel revascularization of the left anterior descending coronary artery (LAD). METHODS: In 256 patients a single left internal mammary artery (LIMA) to LAD bypass was performed with beating heart techniques through a left anterior minithoracotomy (minimally invasive direct coronary artery bypass (MIDCAB), n=129) or a full sternotomy (off-pump coronary artery bypass (OPCAB), n=127). RESULTS: In the OPCAB group, significantly more severe comorbidities (P=0.001) and redo-operations were noted (P<0.001). Conversion to sternotomy or CPB was necessary in five MIDCAB patients and one OPCAB patient. No cerebrovascular accident was seen in both groups. There was no hospital death in MIDCAB- and two deaths in OPCAB procedures (P=ns). There was a significant reduction in time of surgery (P=0.028) and coronary occlusion (P=0.009) in the OPCAB group. No differences in postoperative ventilation time, ICU stay and length of hospital stay were recorded between groups. Wound infections occurred in six MIDCAB patients (4.7%) and one OPCAB patient (0.8%). Early postoperative reoperation due to graft failure was necessary in three patients after MIDCAB and two patients after OPCAB (P=ns). Confirmed by angiography, the early graft patency rate was 96 and 98%, respectively (P=ns). CONCLUSIONS: Both beating heart techniques showed good results with low hospital mortality, low early complications and comparable angiographic results. Nevertheless, MIDCAB is a challenging technique as demonstrated by the longer times of surgery and coronary occlusion with a tendency towards a higher risk of conversion and wound infection. Thus, this technique should only be performed in selected patients with favourable coronary anatomy. Through a sternotomy approach, single vessel revascularization can be performed safely off-pump even in high-risk patients.
Cardiopulmonary Bypass↗
Three-dimensional video and robot-assisted port-access mitral valve operation.
BACKGROUND: In order to minimize surgical trauma, video-assisted mitral valve operation has been started using the Port-Access technique with the addition of a three-dimensional visualization system (Vista Cardiothoracic Systems Inc, Westborough, MA) and a voice-controlled camera-holding robotic arm (Aesop; Computer Motion Inc, Goleta, CA). METHODS: Port-Access mitral valve replacement or repair (PAMVR) was undertaken using an endovascular cardiopulmonary bypass (CPB) system. Fifty patients underwent Port-Access mitral valve replacement or repair. A three-dimensional thoracoscope was inserted allowing complete three-dimensional projection of the mitral valve (Vista). In the last 20 patients, the camera was attached to a robotic arm (Aesop), which allowed stabilization and voice-activated movement of the camera. Mitral valve repair was performed in 26 patients, and the valve was replaced in 24 patients with a mechanical valve prosthesis. RESULTS: Median time of operation was 4.2 hours, aortic cross-clamp time 83 minutes, CPB time 125 minutes, intensive care unit stay 1.5 days and hospitalization 9.0 days. Three months follow-up was complete in 40 patients, with 34 patients (85%) in New York Heart Association class I and 6 patients in class II. Mortality was 0% and rate of reoperation was 2%, with a follow-up time up to 1.5 years postoperatively. CONCLUSIONS: Using three-dimensional video and robotic assistance, it was possible to minimize the length of skin incision, but at the same time to optimally visualize the whole mitral valve apparatus in order to perform true Port-Access mitral valve operation, including various repair techniques.
Adult↗
Clinical use of a computer-enhanced surgical robotic system for endoscopic coronary artery bypass grafting on the beating heart.
The aim of the study was to perform endoscopic coronary artery bypass grafting on the beating heart using a surgical robotic system. In the study, the surgical system ZEUS was used in combination with 3D visualization for endoscopic coronary artery bypass grafting in 25 patients. In a total of 10 cases, the coronary artery anastomosis was done on the beating heart using endoscopic stabilizers without cardiopulmonary bypass. In all cases, total OR time ranged from 4.0 to 8.0 hours (median 5.5 h); the times for endoscopic coronary artery anastomoses ranged from 14 to 50 minutes (median 25 minutes) with no difference between arrested-heart or beating-heart procedures. All patients had an uneventful angiographic control result. An endoscopic coronary artery anastomosis is possible on the arrested as well as on the beating heart.
Cardiopulmonary Bypass↗
Mitral valve annuloplasty: comparison of the mural annulus shortening suture (MASS) with the Carpentier-Edwards prosthetic ring.
BACKGROUND AND AIM OF THE STUDY: Although mitral annuloplasty is an important element of mitral valve repair, the technique employed remains controversial. In this prospective study, we compared two different annuloplasty techniques with regard to hemodynamic performance. METHODS: Between October 1995 and December 1998, 109 consecutive patients underwent mitral valve repair for mitral regurgitation. One group of patients (n = 55) received a Carpentier-Edwards (CE) ring for annuloplasty, and a second group (n = 54) underwent the mural annulus shortening suture (MASS) to reinforce the posterior circumference of the annulus. All patients were investigated prospectively by Doppler echocardiography before discharge and annually thereafter. The mean follow up was 22.7+/-11.6 months. RESULTS: The early mortality rate was 3.7%, with four early deaths in the CE group, and no early death in the MASS group. There was one late death in each group. One patient in each group required reoperation for severe mitral regurgitation after 19 and 30 months, respectively. Postoperative (12 months) Doppler echocardiography showed mean mitral valve gradients to be significantly lower (1.7+/-0.7 versus 2.7+/-1.7 mmHg; p <0.01) and mitral valve areas significantly larger (3.3+/-1.0 versus 2.6+/-0.7 cm2; p <0.01) in MASS patients compared with CE patients. There was no significant difference in mean postoperative mitral regurgitation between the two groups (0.5+/-0.2 versus 0.4+/-0.2). CONCLUSION: Both annuloplasty techniques showed excellent results; however, hemodynamic performance of MASS was superior to that of the rigid CE ring, while not increasing postoperative mitral regurgitation. Therefore, MASS may be recommended as an alternative to annuloplasty rings, if future long-term follow up studies confirm the durability of the technique.
Echocardiography, Doppler↗
Mitral commissurotomy, a technique outdated? Long-term follow-up over a period of 35 years.
BACKGROUND: The objective of this study was to evaluate long-term survival, valve-related complications as well as prognostic factors for early and late outcome after open and closed mitral commissurotomy covering a follow-up period of 35 years. METHODS: From 1955 to 1977, 183 patients with mitral stenosis underwent mitral commissurotomy at our institution. Closed valvotomy was performed on 143 patients (group A) and open valvotomy on 40 patients (group B). RESULTS: Survival rates after 10, 20, and 30 years were 89%, 67.8%, and 49.1% in group A and 91.7%, 66.7%, and 45.9% in group B (p = not significant). The risk of late death increased significantly with an advanced preoperative New York Heart Association functional class, atrial fibrillation, higher age at operation, pre- or postoperative mitral regurgitation, and leaflet calcification. Forty-four patients in group A and 5 patients in group B required reoperation (p < 0.05). Independent predictors for reoperation in a multivariate analysis were a remaining postoperative mitral stenosis or regurgitation. A total of 68 patients showed valve-related complications. The linearized rate of valve-related morbidity and mortality was 2.1% per patient-years in group A versus 1.1% per patient-years in B (p < 0.01). CONCLUSIONS: Long-term survival for open and closed commissurotomy are excellent, showing no difference between the groups. However, both the incidence of reoperation as well as valve-related morbidity and mortality were significantly lower after open commissurotomy. In well-selected patients with pure mitral stenosis and no leaflet calcification, open commissurotomy still remains a valid surgical option.
Adult↗
Early experience with robotic technology for coronary artery surgery.
BACKGROUND: To achieve an endoscopic coronary bypass anastomoses we performed a study with endoscopic robotic instrumentation and camera guidance using three-dimensional (3-D) visualization. METHODS: The surgical robotic system ZEUS (Computer Motion Inc, Goleta, CA) consists of three interactive robotic arms and a control unit allowing the surgeon to move the instrument arms in a scaled down mode. The third arm (AESOP, Computer Motion Inc, Goleta, CA) positions the endoscope via voice control. The study had three phases. Phase I: In a phantom model, end-to-side anastomoses between vein grafts and the left anterior descending coronary artery (LAD) of 109 pig hearts were performed. Phase II: In 6 dogs (FBI, 20-25 kg) the left internal mammary artery (LIMA) was harvested endoscopically. During Port-Access (Heartport Inc, Redwood City, CA) cardiopulmonary bypass (CPB), LIMA and LAD were then anastomosed endoscopically with the help of telemetric ZEUS instruments (Computer Motion Inc). Phase III: A total of seven patients were operated on with help of the ZEUS system (Computer Motion Inc). After endoscopic LIMA harvesting and CPB using the Port-Access (Heartport Inc) system, the bypass graft (LIMA to LAD) was anastomosed endoscopically through three thoracic ports in 2 patients. Another 3 patients were operated on off-pump with regional stabilization and 2 patients with sternotomy and routine CPB. RESULTS: The practice with the phantom model and the subsequent animal experiments allowed the surgeons to gain sufficient experience for the clinical setting. In the clinical cases, times for anastomoses ranged from 20 to 42 minutes. Median internal mammary artery flow rate was 74 mL per minute (range 36-110 mL per minute). One patient in the off-pump group was converted to CPB and routine anastomosis. All patients had an uneventful angiographic control and postoperative course. CONCLUSIONS: Using telemetic technology, a completely endoscopic anastomosis of LIMA to LAD is possible on the arrested heart, as well as on the beating heart.
Anastomosis, Surgical↗
Robotically assisted endoscopic coronary artery bypass procedures without cardiopulmonary bypass.
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Adult↗
Use of the voice-controlled and computer-assisted surgical system ZEUS for endoscopic coronary artery bypass grafting.
OBJECTIVE: With the aim of performing a completely endoscopic coronary bypass anastomosis, we have undertaken an experimental and clinical study using robotic instrumentation and voice-controlled camera guidance. METHODS: The ZEUS Robotic Surgical System (Computer Motion Inc, Goleta, Calif) consists of three interactive robotic arms and a control unit, allowing the surgeon to move the instrument arms in a scaled down mode. The third arm (AESOP, Computer Motion) positions the endoscope via voice control. PHASE I: In a phantom model, vascular grafts were anastomosed to the left anterior descending coronary artery (LAD) of 50 pig hearts with either 2- or 3-dimensional visualization. PHASE II: In 6 dogs (FBI 20-25 kg) the left internal thoracic artery (LITA) was harvested endoscopically. Then the animals were placed on an endovascular cardiopulmonary bypass system (Port-Access, Heartport, Inc, Redwood City, Calif). Anastomosis of the LITA to the LAD was performed endoscopically with the telemetric ZEUS instruments. Flow rates through the LITA were measured by Doppler analysis. PHASE III: Two patients were operated on with the ZEUS system. After endoscopic harvesting of the LITA and cardiopulmonary bypass with the Port-Access system, the bypass graft (LITA-LAD) was anastomosed endoscopically with the ZEUS system through three thoracic ports. RESULTS: In the dry laboratory, the time range required for the robotically assisted coronary anastomosis was 35 to 60 minutes with 2-dimensional visualization and 16 to 32 minutes with 3-dimensional visualization. In the animal experiments, the median time for endoscopic harvesting of the LITA was 86 minutes (range 56-120 minutes) and for the anastomosis, 42 minutes (range 35-105 minutes); flow rates through the LITA ranged between 22 and 45 mL/min. In the clinical cases, preparation times for the LITA were 83 and 110 minutes, respectively, and anastomosis times, 42 and 40 minutes, respectively. Doppler flow rates measured 125 and 85 mL/min, respectively. Both patients had an uneventful follow-up angiogram and postoperative course. CONCLUSIONS: With sophisticated robotic technology, a completely endoscopic anastomosis of the LITA to the LAD is possible, allowing technically precise operations within acceptable time limits.
Anastomosis, Surgical↗
Economic evaluation of different minimally invasive procedures for the treatment of coronary artery disease.
OBJECTIVE: Several different techniques exist within the field of minimally invasive coronary artery surgery. In this study the impact of all these techniques on the total costs and economics has been evaluated. METHODS: Since May 1997, 121 minimally invasive direct coronary artery bypass (MIDCAB) procedures, 125 off-pump coronary artery bypass (OPCAB), ten Port-Access coronary artery bypass (PA-CABG) and 10 endoscopic coronary artery bypass grafting (ENDO-CABG) procedures were performed at our institution. A relative cost analysis of the different procedures was carried out in addition to a thorough evaluation done in five patients of each group dividing the costs into staff-related costs, material-related costs and general hospital costs. The costs were set in relation to regular CABG procedures. RESULTS: Specific less invasive coronary artery surgical techniques, such as the MIDCAB or OPCAB technique already are able to reduce the total costs when compared to regular CABG procedures. Within the Port-Access group as well as the ENDO-CABG group, increased material- and general costs are present when compared to regular CABG leading to increased total hospital costs for PA-CABG and Endo-CABG in Germany. CONCLUSION: At present, MIDCAB and OPCAB procedures are able to reduce total hospital charges, when compared to regular CABG procedures. Increased costs for Port-Access, as well as Endo-CABG surgeries may be compensated in the future by decreased costs due to a shorter phase of rehabilitation and faster return to regular professional activities.
Angioscopy↗
Contrast-enhanced magnetic resonance angiography for control of minimally invasive coronary artery bypass conduits (MIDCAB/OPCAB).
OBJECTIVE: The purpose of this study was to delineate the course and determine the patency of venous and arterial conduits in the early postoperative period following minimally invasive bypass grafting. A less invasive magnetic resonance angiogram was evaluated as alternative to standard contrast angiography and cardiac catheterization. METHODS: Twelve patients (8 males and 4 females) with a mean age of 65.3 (+/- 7.4 ) years were evaluated four to seven days following minimally invasive direct coronary artery bypass surgery (MIDCAB) or off-pump multivessel revascularization with the Octopus stabilizer on the beating heart. Altogether 17 coronary bypass grafts were investigated: 12 left-sided mammary artery grafts to the LAD and five aortocoronary venous bypass grafts. The examination was performed with a 1.5 Tesla Magnetom Vision (Siemens AG, Erlangen) with phased array coil technology. Data acquisition was done with an ultrafast 3D gradient-echosequence in single breathhold and sagittal and coronal views. Contrast enhancement of the vessels was performed with automatic intravenous bolus injection of Gadolinium-DTPA after determination of the individual contrast transit time. Traditional contrast angiography was obtained in all patients during the same time period as a comparison to assess the sensitivity and specificity of the magnetic resonance imaging. RESULTS: All five venous grafts and 11 of the 12 IMA grafts were detected and shown to be patent with the MRA technique. Contrast angiography demonstrated complete patency for all 17 bypass grafts with adequate anastomoses and no evidence of stenosis. The calculated sensitivity for the visualization with MRA was therefore 92% for IMA grafts and 100% for venous grafts. CONCLUSION: The contrast-enhanced ultrafast MRA in single breathhold technique is a reliable, noninvasive method for visualization and determination of the patency of arterial and venous coronary grafts.
Aged↗
A novel mutation in the neonatal region of the fibrillin (FBN)1 gene associated with a classical phenotype of Marfan syndrome (MfS). Mutations in brief no. 163. Online.
Marfan Syndrome (MfS) is an autosomal dominant inherited connective tissue disorder with variable phenotypic expression of cardiovascular, skeletal and ocular manifestations. Cardiovascular complications, such as aortic aneurysm and dissection drastically reduce life expectancy of individuals with MfS, whereas preventive surgery substantially improves the prognosis of these patients. A number of mutations in the fibrillin 1 (FBN1) gene associated with MfS have been identified to date, demonstrating considerable molecular heterogeneity. One region, however, located around exon 24, exhibits a striking clustering of mutations, which are associated with a severe, socalled neonatal form of MfS. Here we report the first mutation (G2950A) in exon 24 of the neonatal region of the FBN1 gene, associated with a classic MfS phenotype. The mutation leads to the subsitution of valin by isoleucin (V984I), both uncharged amino acids, which only differ in a single methyl group. This defect was identified in a proband with cardiovascular manifestations of MfS by SSCP analysis of PCR-amplified genomic DNA, direct PCR sequencing and RFLP analysis. The substitution was neither detected in the unaffected 4-year old daughter of the proband, nor in 3 of his healthy family members nor in 108 allels from control individuals, suggesting that this mutation is causative for MfS in the patient. Since no other family member of the proband is affected by MfS, the defect described is sporadic. In summary, we identified a novel defect in exon 24 of the neonatal region of the FBN1 gene in a patient with a classic phenotype of MfS, suggesting that conservative substitutions in this region may lead to a less severe phenotype of the disease. This finding further demonstrates the remarkable phenotypic heterogeneity associated with FBN1 mutations and stresses the significance of modifying genes and individual alterations in protein function for the pheontypic expression of the disease.
Child, Preschool↗