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Biomedical subjects

B J Messmer

Publications and source records attributed to B J Messmer.

At least 91 records · Page 5Linked to original sources
PubMed1994

One-stage intrathoracic repair of extended aortic aneurysms.

Aneurysms of the entire thoracic aorta are usually approached in two to three stages. From 1990 to 1994, we performed one-stage aortic replacement from the root to the diaphragm in 16 patients (8 men and 8 women with a mean age of 55.7 years, range 49 to 73). There were 11 type A dissections, 7 of which were acute. Six patients underwent aortic valve reconstruction; seven had aortic root replacement by Bentall or Cabrol techniques. In two cases, the innominate artery had to be replaced by a vascular graft separately in addition to reimplantation of the supraaortic branches as an island flap into the arch prosthesis. In eight cases, a median sternotomy was used; eight had a bilateral transverse thoracotomy. The procedure was performed under deep hypothermic circulatory arrest in all cases (mean duration 50.5 min, range 38 to 62 min). Two patients, both operated upon for an acute dissection, expired perioperatively: one due to a bronchopneumonia, and one because of a thrombosed Cabrol graft to the right coronary artery. No patient developed bleeding or neurological complications. At a mean follow-up of 26.9 months (1 to 50 months), all patients discharged from the hospital were still alive. Four patients underwent subsequent thoracoabdominal aortic replacement. This experience suggests that complete thoracic aortic replacement can be performed in a single session with an operative risk comparable to that of the conventional two-stage approach. The bilateral transverse thoracotomy affords excellent exposure. The lack of spinal cord ischemia may be the result of spinal cord protection with hypothermic circulatory arrest and use of the open-clamp technique.

Acute Disease↗
PubMed1994

Complement, leukocytes, and leukocyte elastase in full-term neonates undergoing cardiac operation.

In 13 neonates undergoing cardiac operations for congenital cardiac defects, complement, leukocytes, and leukocyte elastase were studied during and after cardiopulmonary bypass. All but two neonates received prostaglandin E1 before the operation. The C3d/C3 ratio rose significantly during cardiopulmonary bypass from 0.86 +/- 0.55 to 1.40 +/- 0.56 (mean +/- standard deviation; p < 0.0001). Abnormally elevated C5a levels (18.6 +/- 7.3 micrograms/L) were measured at the end of cardiopulmonary bypass. C4 was not overtly consumed during the procedure. Leukocytes fell from a preoperative value of 10.06 +/- 3.15 x 10(9)/L to 3.21 +/- 0.64 x 10(9)/L after beginning of cardiopulmonary bypass (p < 0.0001) and rose at the end of the procedure from 2.33 +/- 0.67 x 10(9)/L to 7.19 +/- 1.84 x 10(9)/L, after protamine administration (p < 0.0001). Neutrophils fell from a preoperative value of 5.14 +/- 1.18 x 10(9)/L to 1.46 +/- 0.35 x 10(9)/L after beginning of cardiopulmonary bypass and rose at the end of extracorporeal circulation from 1.00 +/- 0.31 x 10(9)/L to 4.10 +/- 1.18 x 10(9)/L, after protamine administration (p < 0.005). Elastase release occurred in all neonates during cardiopulmonary bypass and averaged 331.5 +/- 175.7 micrograms/L. Complement activation and leukocyte stimulation did not correlate with postoperative complications or outcome. This study demonstrates complement activation and leukocyte stimulation in neonates undergoing cardiac operation.

Alprostadil↗
PubMed1994

Prophylactic reoperation for strut fractures of the Björk-Shiley convexo-concave heart valve.

Outlet strut fracture of the Björk-Shiley Convexo-Concave (C/C) heart valve is the current paradigm of structural failure of mechanical heart valve prostheses. The estimated risk of fracture for C/C valves varies from 0.02% to 2.5% per patient-year, depending on valve size, opening angle, date of manufacture and position as a mitral or aortic replacement. This report examines our experience with 396 implants, comprising 346 C/C 60 degrees valves and 50 C/C 70 degrees valves. The 30-day mortality was 1.8%. Through April 1993, mean follow up was 8.9 years, incorporating 2971 patient-years and knowledge of the current status of 91.5% (356/389) of operative survivors. Late mortality was 3.7% per patient-year, including one 60 degrees and one 70 degrees outlet strut fracture. To evaluate the risk of semi-elective valve re-replacement at our institution, we reviewed the results of isolated re-replacements of failing or incipiently failing bioprostheses in 65 patients who had no serious co-morbidity and who were NYHA Class III or lower immediately before the procedure. The 30-day mortality was 4.6% and the overall serious morbidity rate was 10.8%, necessitating six repeat reoperations. When these factors were balanced against the life expectancy and general status of five patients with large-size, higher-fracture-risk 70 degrees C/C valves, it was concluded that only two patients remained possible reoperation candidates. Consideration for re-replacement of a normally functioning C/C heart valve should take into account institution-specific experience because structural failure remains a low risk compared to valve-related complications engendered by reoperation.

Adult↗
PubMed1993

Multiple system organ failure after open heart surgery in infants and children.

Between January 1985 and March 1989 we retrospectively observed multiple system organ failure (MSOF) in 16 of 460 children (3.5%) who underwent cardiac surgery with cardiopulmonary bypass for congenital heart disease. MSOF was arbitrarily defined as a clinical entity with failure of two or more vital organ systems associated with high fever, thrombocytopenia, and cardiocirculatory insufficiency and occurring within the first postoperative week. In 13 children the first clinical manifestations of MSOF were evident on the first post-operative day and in the other 3 on the second or third post-operative day. All children showed acute renal failure, acute hepatic failure, high fever, and thrombocytopenia. Most of them showed respiratory insufficiency and neurological involvement. Seven of the 16 children died. Four of the 9 surviving patients had neurological sequelae still present 6 months after the operation, and the others recovered completely.

Cardiac Surgical Procedures↗
PubMed1993

Evaluation of aortic coarctation after surgical repair: role of magnetic resonance imaging and Doppler ultrasound.

OBJECTIVE: To compare the usefulness of magnetic resonance imaging (MRI) and Doppler ultrasound with that of cross sectional echocardiography and oscillometric blood pressure measurement for the evaluation of aortic coarctation after surgical repair. DESIGN: Prospective study. Aortic diameters measured by cross sectional echocardiography, MRI, and angiography (selected cases) and functional data determined by physical examination, oscillometric blood pressure measurement, and continuous wave Doppler. SETTING: Tertiary referral centre. PATIENTS: 40 patients aged 2-28 years (mean 10.6 years) who had had surgical correction of aortic coarctation (mean follow up 5.7 years). RESULTS: In all patients MRI gave diameter measurements of the aortic arch and the thoracic aorta whereas in half of them cross sectional echocardiographic measurement of the isthmic region failed. The correlation coefficient for aortic diameters measured by MRI and angiography was 0.97 and that between MRI and echocardiography was 0.89. Peak velocities in the descending aorta correlated better with residual narrowing of the aortic isthmus or distal aortic arch or both than systolic blood pressure gradients between the upper and lower limbs. A peak velocity of < 2 m/s in the descending aorta during systole excluded important restenosis. Prolongation of anterograde blood flow during diastole always indicated a morphological abnormality--either important restenosis or aneurysmal dilatation. CONCLUSIONS: MRI was better than cross sectional echocardiography for imaging the aortic arch after coarctation repair and measuring its diameter. Peak velocity in the descending aorta correlated better with residual stenosis than did the systolic blood pressure gradient between the upper and lower limbs and this index could be used to indicate a need for MRI.

Adolescent↗
PubMed1993

Complement activation during cardiopulmonary bypass in infants and children. Relation to postoperative multiple system organ failure.

Twenty-nine children 3 months to 17 years of age undergoing operations for congenital heart disease were included in this prospective study. Complement activation, activation of the plasma contact system, leukocytes, leukocyte elastase release, and C-reactive protein were studied during and after cardiopulmonary bypass for the first postoperative week and related to multiple system organ failure occurring in eight (27.5%) of the 29 children. During cardiopulmonary bypass complement activation via the alternative pathway as indicated by significant conversion of C3 (expressed by C3d/C3) and abnormally high C5a values at the end of cardiopulmonary bypass without consumption of C4 was shown in all children. At the end of cardiopulmonary bypass, C3 conversion was significantly higher in the eight patients with multiple system organ failure than in the others (p < 0.05), whereas no difference in C5a level was shown. All children had a significant increase in leukocyte count directly after protamine administration (p < 0.0001) and elastase release during cardiopulmonary bypass that was significantly higher in patients with multiple system organ failure than in those without (p < 0.05). Consumption of prekallikrein as an indicator of activation of the Hageman system was not detectable during cardiopulmonary bypass in any child. After cardiopulmonary bypass, in patients without multiple system organ failure, C3d/C3 decreased and reached preoperative values within the first postoperative week, whereas, in patients with multiple system organ failure, C3d/C3 increased further, reaching a maximal value on the third postoperative day. In comparison with patients without multiple system organ failure, patients with multiple system organ failure showed a severe decrease of C4 (with minimal values on the third postoperative day), suggesting consumption by activation of the classic pathway of the complement system or a hepatic synthesis deficiency. Prekallikrein values were also significantly lower in patients with multiple system organ failure than in the others, with a maximal difference on the third postoperative day (p < 0.005). C-reactive protein was significantly lower in patients with multiple system organ failure than in the others for the first 2 postoperative days (p < 0.05), probably because of severe hepatic failure in patients with multiple system organ failure. This study demonstrates that, in children, cardiopulmonary bypass induces complement activation principally via the alternative pathway. It suggests a relationship between complement activation and multiple system organ failure observed in the postoperative period. Furthermore, it points out the role of multiple system organ failure itself on the C3 conversion and on the synthesis of the markers of the inflammatory response in children after heart operations.

Adolescent↗
PubMed1992

Internal mammary artery bypass graft for impaired coronary perfusion after neonatal arterial switch operation.

Myocardial ischaemia caused by perfusion impairment of translocated coronary arteries is the major cause of perioperative mortality after neonatal arterial switch operation for transposition of the great arteries. We report the successful use of the right internal mammary artery as a bypass graft to a dominant right coronary artery to treat insufficient perfusion of this artery in a newborn. Eight months later, coronary angiography showed a full blood supply of the right coronary artery across the internal mammary anastomosis. After a follow-up period of more than 30 months, somatic development, electrocardiogram and echocardiographically determined contractility of both ventricles are practically normal indicating regular function of the bypass graft.

Coronary Angiography↗
PubMed1991

Surgical correction of coarctation in early infancy: does surgical technique influence the result?

Between 1979 and 1988, a total of 53 infants less than 1 year of age underwent repair of coarctation. Thirty-seven patients (70%) were younger than 3 months. Median age was 0.9 month. Four different surgical techniques were used: resection with end-to-end anastomosis, patch enlargement, subclavian flap aortoplasty, and subclavian displacement aortoplasty (Meier-Mendonca technique). Hospital mortality was 7.5% and was limited to patients with additional complex intracardiac defects. Neither age nor surgical technique had an influence on the operative risk. Follow-up averaged 15 to 43 months for the four different groups. Restenosis developed in 9 (19%) of 47 patients regularly followed up, 5 (11%) of whom have had reoperation. Age at operation was not a predictor for restenosis, which occurred in 17.4% of patients less than 1 month and 20.8% of those greater than 1 month of age at operation. Patch enlargement and the subclavian displacement technique demonstrated the highest restenosis rates (42% and 43%, respectively). However, patients who underwent patch enlargement had less favorable pathological conditions. It is concluded that results of coarctation repair in early infancy do not depend as much on the operative method itself as on the specific pathological aspect, which largely determines the method of treatment. Some reservation must be made in regard to the subclavian displacement technique.

Anastomosis, Surgical↗
PubMed1991

Surgery for critical congenital aortic stenosis during the first three months of life.

Open commissurotomy for critical aortic stenosis has been performed in a consecutive series of 28 neonates and infants below 3 months of age (average age 1 month) including 5 patients with severe organic mitral valve disease in need of concomitant correction. In the majority of cases, aortic stenosis was due not only to fused commissures but also to excessive immature valve tissue protruding into the valve area. Therefore a technique of extended commissurotomy has been adopted resecting such nodules responsible for a secondary level stenosis. All operations were done under deep hypothermia (17 degrees C), circulatory arrest (33 +/- 11 min) and cardioplegia using the Bretschneider solution (35-50 ml/kg). Hospital mortality was 18% (5) including 1 infant dying at 2 months of thrombosed mitral prosthesis inserted at a secondary operation. Severe organic mitral valve disease proved to be the only significant risk factor for early mortality. During the follow-up period of up to 10 years (average 5 years), 1 child with a hypoplastic left heart died and 2 children had to undergo reoperation for residual and recurrent stenosis, respectively. Actuarial survival for the present series is 78% at 10 years while reoperation free survival for the aortic valve is 64%. It is concluded that careful and if necessary extended open commissurotomy still represents the method of choice in this age group. Alternative methods such as transventricular or percutaneous dilatation did not show a lower risk until now and long-term results are not convincing as yet.

Actuarial Analysis↗
PubMed1991

Development and training of skeletal muscle ventricles with low preload.

One-layered skeletal muscle ventricles (SMV) were constructed from latissimus dorsi (LD) muscles extrathoracally in six calves and trained under electrical stimulation on totally implanted mock circulation systems. These ventricles had low preloads of about 5 mmHg. The results showed that training against a resistance similar to the human aorta does not create an effective blood pump. But conditioning against a highly complaint workload makes them six times more effective. Therefore, further research on this observation is mandatory. After a conditioning of 16 to 63 days, all implanted mock circulations became infected due to perforated skin, so these experiments had to be terminated. To avoid these infections, we developed and tested an intrathoracic implantable mock circulation system with a highly compliant workload. With a double-layered muscle pump, systolic pressure 120-140 mmHg was generated and an output of more than 31/min was obtained. SMVs with a low end-diastolic pressure seem to be suitable for construction of an effective blood pump between the left atrium and the aorta as a left heart assist device.

Animals↗
PubMed1990

New site for pacemaker generators in children.

Bipolar pacemaker implantation was performed in three children, aged 5, 6 and 9 years. The two epimyocardial fishhook pacing electrodes were inserted through different incisions. After resection of the anterior part of the 5th and 6th rib, the generator was placed into a pocket with the posterior wall resulting from the remaining periostium/perichondrium and the anterior wall consisting of the isolated intercostal and pectoral muscle. The leads were brought in extrapleurally and connected to the generator. The operations were conducted without perioperative and late postoperative complications.

Child↗
PubMed1990

Echocardiographic evaluation of systolic left-ventricular function in infants with critical aortic stenosis before and after aortic valvotomy.

Infants with critical aortic stenosis may have global or regional left ventricular contraction abnormalities. In order to evaluate the clinical significance of these contraction abnormalities, we examined the systolic left ventricular function before and after aortic valvotomy in 16 infants operated on between 1980 and 1987. Left ventricular free wall and septal motion were studied by cross sectional echocardiography using the apical 4-chamber view. Enddiastolic and endsystolic left ventricular frames were digitized. The relative systolic reduction of the total left ventricular area (reflecting ejection fraction) as well as of 5 left ventricular sectors (reflecting regional wall motion) was calculated and compared to previously established normal values. Before valvotomy, 8 infants had normal and the other 8 impaired left ventricular systolic wall motion. These latter infants showed hypokinesia of the apex and/or the posterolateral left ventricular wall resulting in a decreased systolic reduction of the total left ventricular area. Four of these infants had evidence of myocardial infarction on intraoperative inspection. Early after operation, the systolic reduction of the total left ventricular area was normal in all infants, and the left ventricular apex and poster-lateral wall were either normo- or hyperkinetic. Follow-up studies of all infants more than 10 months and of 7 infants more than 3 years after operation showed that the left ventricular systolic wall motion remained normal in all, irrespective of whether it was normal or abnormal preoperatively. This study suggests that left ventricular contraction abnormalities in infants with critical aortic stenosis may be reversible and thus do not constitute a contraindication against aortic valvotomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve↗
PubMed1990

Transient transcatheter balloon closure of patent foramen ovale following surgical repair of critical pulmonary stenosis.

Severe cyanosis resulting from postoperative atrial right-to-left shunt is a life-threatening complication. We present a technique of transient transcatheter balloon closure of a patent foramen ovale in a newborn operated on for critical pulmonary stenosis, where the foramen ovale had been left open intraoperatively. Cardiac catheterization was performed under echocardiographic control in the intensive care unit and the foramen ovale was occluded with a water-filled balloon-catheter. Significant improvement of arterial oxygen tension allowed delayed definitive surgical closure in a second step. Unfortunately, the child developed right-sided pneumothorax postoperatively and died of cardiopulmonary failure. Nevertheless, this procedure seems a suitable way to relieve atrial right-to-left shunt temporarily until definitive surgical closure can be performed.

Anastomosis, Surgical↗
PubMed1990

[Limits of early ambulation following heart surgery from the viewpoint of the pediatric cardiologist].

Early mobilization after cardiac surgery in children may be limited by various postoperative problems. These are mainly congestive heart failure, respiratory insufficiency, general or local infections, postoperative cardiac arrhythmias, and a number of other postoperative complications. We examined the postoperative course of 297 children operated in the period 1986-1989 for congenital defects of the heart and great vessels. Fifty of these patients were newborns, 92 were infants, 98 young children, and 57 school-age children. In 37% of the patients, no postoperative problems were observed; 31% had problems without prolongation of hospitalization, and 32% developed problems which delayed discharge from hospital. Further analyzed was the postoperative course of patients after closure of a patent ductus arteriosus (19), correction of aortic coarctation (39), secundum atrial septal defect (26), ventricular septal defect (46), and complete atrio-ventricular canal (15), construction of a Blalock-Taussig-anastomosis (19) or a central aortopulmonary shunt (9), correction of Fallot's tetralogy or pulmonary atresia with ventricular septal defect (25), correction of simple complete transposition of the great arteries by the arterial switch-operation (25) or a Senning-procedure (27), and finally, after a Fontan-Operation (9). We found, as expected, that patients after operation of simple cardiovascular defects had few postoperative complications and could be mobilized early and discharged. In contrast, patients after operation of complex cardiac defects frequently developed postoperative problems which delayed early mobilization and discharge. Newborns, infants, and young children regulate their own degree of mobility and, as a rule, behave adequately in this respect. Older children sometimes must be encouraged to move more or, to the contrary, must be restrained from too early or too strenuous movement.

Adolescent↗