[Portable NMR-MOUSE: a new method and its evaluation of the Achilles tendon]

AIM

The increased demands placed on the Achilles tendon in recreational and professional sports have led to a rise in pathological changes in this anatomic region. Magnetic resonance evaluations of the tendon have proven to be a valid but expensive and stationary diagnostic tool. In this study, a new mobile NMR sensor was to be tested in the evaluation of the Achilles tendon.

METHOD

The technical development of the so-called NMR-MOUSE ( Mobile Universal Surface Explorer) represents a novelty with an open and portable sensor. To appraise its diagnostic efficacy, healthy athletes (professional soccer players, track and field, as well as aquatic athletes), healthy controls and patients with Achilles tendon lesions were evaluated. As an accessible, sensitive and reproducible parameter for the study the transverse relaxation time T2 with its angular dependency was chosen. As part of the examination, the relaxation times of the skin, the tendon and the surrounding soft tissue were determined.

RESULTS

During the evaluation with the NMR-MOUSE, the skin and peritendineous tissue exhibited relatively long T2 relaxation times, while the tendon itself had significantly shorter T2 times, allowing for a clear differentiation of the structures. The T2 relaxation time of the Achilles tendon in the control group averaged 5.8 ms. The MRI-MOUSE was able to demonstrate an increase in the T2 relaxation times in patients with pathological lesions of the tendon due to the increased water retention of the tissue.

CONCLUSION

The novel NMR-MOUSE represents a cost efficient and portable sensor, which allows for a reliable evaluation of surface structures, such as the Achilles tendon. The anisotropic structure of the tendon and the surrounding soft tissue can be reliably differentiated with the help of the NMR-MOUSE.

[Triangular vertebropelvine stabilisation of unstable posterior pelvic ring fractures]

It is the objective of this investigation to describe the early results (2 years outcome) after triangular vertebropelvine stabilisation (TVPS) of unstable fractures of the posterior pelvic ring.

PATIENTS

Between 1.1.1997 and 31.12.2000 35 patients were treated. C1 fractures occurred 9 times (25.7 %), C2 injuries 16 times (45.7 %) and 10 patients suffered fom C3 fractures (28.6 %). The mean age of the injured was 36.6 years (15 to 77 years). 22 patients (62.8 %) were treated with the TVPS. Suffering from a monotrauma, mobilisation with full weight bearing of the injured pelvis was resumed immediately on the first postoperative day. In case of polytrauma mobilisation was continued when the additional injuries allowed so, after 8.8 days on average.

RESULTS

After an average of 23.4 months 18 of 22 patients with TVPS were controlled. Radiological criteria as well as quality of life were ascertained. It could be proved, that TVPS offered good reduction and stable retention of the pelvic fractures. 16 patients (89.0 %) suffered from moderate or mild pain, 15 (83.3 %) had slight problems in walking. No restriction in the range of motion of the lumbal vertebral column could be observed.

CONCLUSION

The following advantages of the TVPS could be demonstrated: anatomical reduction and stable retention of instable pelvic fractures, full weight bearing from the first day after surgery, and only slight restriction of the quality of life two years after operation

[Short bowel ileus due to a stenotic ileocecal tumor of tuberculous origin]

Abdominal tuberculosis is a rare disease. Therapy usually consists in drug treatment while surgery is only performed in complicated cases. We report on a 75 year-old man who presented with clinical and radiologic signs of bowel obstruction. The patient complained of weight loss and B-symptoms. There was a history of drug treatment for tuberculosis of the neck and throat in the medical department four weeks prior to admission. Intraoperatively a coecum stenosis was found due to a large tumor that macroscopically appeared with a diffuse carcinomatosis of the peritoneum. A right hemicolectomy was performed. Histopathology findings revealed a granulomatous inflammation with epithelioid cells. Signs of peritoneal carcinomatosis were not seen. The patient recovered well after an additional tuberculostatic treatment and was discharged after 14 days. At present he is free of symptoms. Even after tuberculostatic treatment lymphatic tuberculosis might show signs of progression that can lead to an abdominal presentation.

Trendelenburg positioning after cardiac surgery: effects on intrathoracic blood volume index and cardiac performance

BACKGROUND AND OBJECTIVE

The efficacy of the Trendelenburg position, a common first step to treat suspected hypovolaemia, remains controversial. We evaluated its haemodynamic effects on cardiac preload and performance in patients after cardiac surgery.

METHODS

Twelve patients undergoing mechanical ventilation of the lungs who demonstrated left ventricular 'kissing papillary muscles' by transoesophageal echocardiography, thus suggesting hypovolaemia, were positioned 30 degrees head down for 15 min immediately after cardiac surgery. Cardiac output by thermodilution, central venous pressure, pulmonary artery occlusion pressure, left ventricular end-diastolic area by transoesophageal echocardiography and intrathoracic blood volume by thermo- and dye dilution were determined before, during and after this Trendelenburg manoeuvre.

RESULTS

Trendelenburg's manoeuvre was associated with increases in central venous pressure (9 +/- 2 to 12 +/- 3 mmHg) and pulmonary artery occlusion pressure (8 +/- 2 to 11 +/- 3 mmHg). The intrathoracic blood volume index increased slightly (dye dilution from 836 +/- 129 to 872 +/- 112 mL m(-2); thermodilution from 823 +/- 129 to 850 +/- 131 mL m(-2)) as did the left ventricular end-diastolic area index (7.5 +/- 2.1 to 8.1 +/- 1.7 cm2 m(-2)), whereas mean arterial pressure and the cardiac index did not change significantly. After supine repositioning, the cardiac index decreased significantly below baseline (3.0 +/- 0.6 versus 3.5 +/- 0.8 L min(-1) m(-2)) as did mean arterial pressure (76 +/- 12 versus 85 +/- 11 mmHg), central venous pressure (8 +/- 2 mmHg) and pulmonary artery occlusion pressure (6 +/- 4 mmHg). The intrathoracic blood volume index and left ventricular end-diastolic area index did not differ significantly from baseline.

CONCLUSIONS

Trendelenburg's manoeuvre caused only a slight increase of preload volume, despite marked increases in cardiac-filling pressures, without significantly improving cardiac performance.

Left ventricular assist stand-by for high-risk cardiac surgery

BACKGROUND

Patients with severely impaired left-ventricular pump function who are eligible for heart transplantation increasingly undergo high-risk cardiac surgery due to the scarcity of donor organs. If these patients also qualify for long-term mechanical support, the latter can be used as back-up in case of postcardiotomy failure.

METHODS

Since 1994, 36 patients (34 male, 2 female; mean age 51 +/- 7 years) underwent coronary bypass surgery/aneurysmectomy (n = 27), aortic valve replacement (n = 4), both (n = 1), or partial left ventriculectomy (n = 4) with a long-term mechanical assist device (Novacor, HeartMate, DeBakey) and were kept on stand-by with the device. Average left ventricular ejection fraction was 23 +/- 9 %, NYHA 2.9 +/- 0.5, and CCS 2.7 +/- 0.9. An intraaortic balloon pump was inserted prior to surgery in 13 patients.

RESULTS

In 31 patients, high-risk surgery was performed, whereas 5 patients underwent immediate device placement as coronary revascularization was deemed impossible. 6 patients had postcardiotomy failure after coronary bypass surgery and were immediately provided with a long-term assist system. There were no significant differences in risk factors between the patient subsets. All conservatively operated patients survived and left the institution after 9.4 days and are currently at NYHA 1.5 +/- 0.5 or CCS 1.0 +/- 0, respectively. 6 of the 11 LVAD patients could be bridged to heart transplantation after 43 - 418 days, and 1 patient is still on support.

CONCLUSION

High-risk conventional surgery with LVAD stand-by is feasible and seems to be a valuable alternative for heart-transplant candidates.

Mitral valve surgery in patients with poor left ventricular function

BACKGROUND

Mitral valve surgery for the correction of secondary mitral valve regurgitation (MR) in cardiomyopathy is associated with a poor outcome. Numerous studies have identified a severe left ventricular dysfunction as an indicator for a poor prognosis. The aim of the study was to asses the follow-up after mitral valve surgery and severe left ventricular dysfunction.

METHODS

Between 1994 and 2000, 31 patients with mitral regurgitation and a left ventricular ejection fraction of below thirty percent undergoing isolated repair (n = 16) or replacement (n = 15) were investigated. All patients received maximal drug therapy. Twenty-one patients were New York Heart Association (NYHA) class III and 10 were class IV. Follow-up with echocardiography, ECG, and chest x-ray was performed in 87 % of the survivors. The mean duration of follow-up was 39 +/- 16 months.

RESULTS

The mean duration of ICU and hospital stay was 3.6 +/- 2.1 days and 8.1 +/- 5.4 days, respectively. The 1-, 2-, and 5-year survival rates were 91 %, 84 %, and 77 %, respectively. NYHA class improved from 3.3 +/- 0.8 to 2.1 +/- 0.7 at follow-up (p < 0.01). The ejection fraction improved from 23.1 +/- 6.6 % to 36 +/- 6.8 % at follow-up (p < 0.02). Freedom from readmission for heart failure was 85 %, 79 %, and 68 % at 1-, 2-, and 5 years, respectively.

CONCLUSIONS

Mitral valve surgery improves left ventricular function and reduces heart failure severity in patients with MR and cardiomyopathy. High-risk mitral valve surgery may be an alternative to heart transplantation in selected patients.

Myocardial ischaemia in patients with impaired left ventricular function undergoing coronary artery bypass grafting--milrinone versus nifedipin

BACKGROUND AND OBJECTIVE

Myocardial ischaemia and infarction are major complications immediately after coronary artery bypass grafting. They may be due to incomplete surgical revascularization, perioperative anaesthetic management or vasospasm of arterial grafts, e.g. the internal mammary artery. Infusions of nifedipine or milrinone have been advocated to prevent spasm of the mammary artery. The study compared the incidence of myocardial ischaemia after continuous infusion of either nifedipine (0.2 microg kg(-1) min(-1)) or milrinone (0.375 microg kg(-1) min(-1)) in patients with compromised left ventricular function scheduled for elective coronary artery bypass graft.

METHODS

After Institutional Review Board approval, this double-blinded randomized clinical study enrolled 30 adult patients with compromised left ventricular function (ejection fraction < 0.4) scheduled for elective coronary artery bypass grafting after written informed consent had been obtained. Ischaemia was detected by Holter electrocardiographic monitoring. The incidence of myocardial cell death was monitored by serial determinations of the creatine kinase-MB (CK-MB) and troponin-I.

RESULTS

New ST elevation > or = 0.2 mV or new ST depression < or = 0.1 mV occurred in five of 15 patients in the milrinone group (33.3%) and in 13 of 15 patients (86.6%) in the nifedipine group (P < 0.05). There were increases in CK-MB and troponin-I in both groups. Twenty-four hours postoperatively, CK-MB (P = 0.003) and troponin-I (P = 0.001) were significantly higher in the nifedipine group.

CONCLUSIONS

Perioperative continuous infusion of milrinone, compared with nifedipine, results in a significantly lower incidence of myocardial ischaemia and myocardial cell damage after elective coronary artery bypass grafting.

[Population development and economic growth. A simulation analysis for Switzerland]

"A simulation exercise of a general equilibrium model for Switzerland makes clear that the macroeconomic impacts of aging populations are not very strong. There is no need for urgent policy actions to avoid severe negative economic consequences....However, the aging of population affects negatively the net income of the active labor force. An increasing share of their gross salaries goes to the retirement system to finance the pension payments of a growing number of pensioners. Attempts to moderate the elderly dependency ratio would lower this burden for the active labor force. Options are an increase of the female participation rate, an increase of the labor participation rate of the elderly--[which] also means a higher retirement age--and an increasing flow of immigrants. But socioeconomic problems might probably generate practical limits on the extent to which immigration can be increased." (SUMMARY IN ENG AND FRE)

Congenital myasthenic syndrome (CMS) in three European kinships due to a novel splice mutation (IVS7 - 2 A/G) in the epsilon acetylcholine receptor (AChR) subunit gene

Mutations in the epsilon-acetylcholine receptor (AChR epsilon) subunit gene cause congenital myasthenic syndromes (CMS) with postsynaptic neural transmission defects. We present 3 male and 2 female patients from three unrelated Croatian, Hungarian, and Russian families with autosomal recessive CMS. All patients manifested with variable degrees of ophthalmoparesis and generalized, fatiguable muscle weakness since birth or early infancy. Electrophysiological studies showed a decremental response in all patients indicating a neuromuscular transmission defect. Pyridostigmine treatment improved the proximal muscle weakness whereas the ophthalmoparesis remained unchanged in all patients. Analysis of the AChR epsilon subunit gene showed homozygosity for a novel splice site mutation of intron 7 epsilon(IVS7-2A/G) in the two Croatian siblings. epsilon-mRNA analysis by RT-PCR and direct sequencing revealed that exon 7 was spliced directly to exon 9 with skipping of exon 8. The Hungarian and Russian patients were heteroallelic carriers of the same mutation epsilon(IVS7-2A/G) and of a frameshifting mutation epsilon 70insG and epsilon 1293insG, respectively. We hypothesize that altered splice products may not be expressed as functional receptors at the cell surface. A haplotype analysis with polymorphic markers revealed a high degree of similarity for the epsilon(IVS7-2A/G) carrying allele in all families and may therefore indicate a common origin of the mutation.

[Outpatient treatment of acute deep venous thrombosis of the lower limbs]

The outpatient management of acute deep vein thrombosis could replace the inpatient care for most patients. Fixed-dose, weight-adjusted low-molecular-weight heparins, as efficacious and safe as unfractionated heparin, allow home treatment for selected and eligible patients. The main exclusion criteria are severe renal insufficiency, high risk of bleeding, pulmonary embolism with unstable hemodynamics, allergy to heparin and suspected non-compliance. Programs for outpatient management need, after appropriate selection, adequate patient education, easy access to health-care professionals and daily follow-up during heparin treatment.

[Molecular biology of cystinuria]

Cystine stones belong to the kidney stones diseases which are difficult to manage due to the high rate of recidivation and the necessary surgical procedures. Cystinuria is an autosomal recessive defect of the transport of cystine and the dibasic amino acids in the proximal kidney tube. Recently, two subunits of a renal cystine transporter have been identified. Mutations in these genes have been shown to lead to the cystinuria phenotype. Genetic and functional analyses have helped to modify the classification of cystinuria which had previously been exclusively based on biochemical data. Furthermore, first steps towards a molecular genetic testing have been carried out replacing the so far diagnostic procedure which are stressing for the patients. The results of these testings make an individual therapy possible.

Analysis of the genes SLC7A9 and SLC3A1 in unclassified cystinurics: mutation detection rates and association between variants in SLC7A9 and the disease

Cystinuria is a common inherited disorder of defective renal reabsorption of cystine and dibasic amino acids. Recently, 2 responsible genes have been identified: mutations in the SLC3AI gene encoding the glycoprotein rBAT cause cystinuria type I, while variants in the SLC7A9 gene have been demonstrated in non-type I cystinuria; its gene product b(0)+AT is the light chain of the renal cystine transport system rBAT/b(0),+-AT. To estimate the role of both genes in the etiology of cystinuria, we searched for sequence alterations in SLC7A9 and SLC3AI: 30 unclassified cystinurics were investigated. In 50% of patients (15/30), point mutations in SLC3A1 were detected. Screening of the SLC7A9 gene revealed 10 mutations in 8 patients corresponding to a frequency of 27%. In addition to previously published mutations in the SLC7A9 gene, we detected 2 new mutations (F 140S, c747delG). An overall detection rate of 73% (22/30) in unclassified patients is delineated for mutations in both genes. In 33% (10/30), 2 mutations were detected, in 40% (12/30) 1 mutation. Furthermore, 5 new polymorphic sites were identified in SLC7A9. While the base pair variation in intron 9 is homogeneously distributed in patients and control individuals, the allelic and genotypic distributions of the polymorphisms in 3 exons of SLC7A9--exons 2, 5 and 6--and intron 3 differ significantly between both groups. Our results suggest that some haplotypes defined through the exons 2, 5 and 6 and intron 3 might be markers of a functional variant in the SLC7A9 gene. Evidently, since the mutation detection rates in the 2 so far known cystinuria genes never reach 100%, further genes and modulating factors should influence the phenotype in a subset of patients. However, the presented data show that testing for mutations in the 2 currently known cystinuria genes is already a meaningful approach to the molecular diagnostics of the disease.