Biomedical subjects

F Haas

Publications and source records attributed to F Haas.

At least 19 recordsLinked to original sources

PubMed2006

Fast-track surgery in laparoscopic radical prostatectomy: basic principles.

Fast-track surgery describes innovative treatment concepts ensuring a faster convalescence phase. The aim of this study was to allow hospital discharge 3 days after surgery without additional complications in patients receiving LRPE for localized prostate cancer. Twenty-five patients each were randomized in the study groups to verify if a fast-track regimen could be transferred into clinical routine. The perioperative data, early complications, hospital stay as well as readmission rate were analyzed. The mean postoperative stay was 3.6 days in the fast-track group versus 6.7 days in the conventional group. The overall complications were significantly less in the fast-track procedure. The readmission rate was low and not significant. Patients receiving an LRPE benefit from a suitable fast-track concept. The postoperative hospital stay could be shortened nearly by half with a significantly decreased overall complication rate. Thus, fast-track concepts might contribute to saving resources in the long term. However, more evidence based on larger prospective trials is needed to achieve optimal quality of life for patients perioperatively.

Aged↗

PubMed2006

Decrease of thalamic gray matter following limb amputation.

Modern neuroscience has elucidated general mechanisms underlying the functional plasticity of the adult mammalian brain after limb deafferentation. However, little is known about possible structural alterations following amputation and chronic loss of afferent input in humans. Using voxel-based morphometry (VBM), based on high-resolution magnetic resonance images, we investigated the brain structure of 28 volunteers with unilateral limb amputation and compared them to healthy controls. Subjects with limb amputation exhibited a decrease in gray matter of the posterolateral thalamus contralateral to the side of the amputation. The thalamic gray matter differences were positively correlated with the time span after the amputation but not with the frequency or magnitude of coexisting phantom pain. Phantom limb pain was unrelated to thalamic structural variations, but was positively correlated to a decrease in brain areas related to the processing of pain. No gray matter increase was detected. The unilateral thalamic differences may reflect a structural correlate of the loss of afferent input as a secondary change following deafferentation.

Adolescent↗

PubMed2006

[Severing of the tibial nerve with stripping of the lesser saphenous vein--a rare complication of surgery for varicosity].

Neurological complications are rare with surgery for varicosities and usually involve the saphenous, peroneal, or sural nerve. When the saphenous vein is stripped in the popliteal region, there is danger of tibial nerve injury due to the topographic situation. We report a serious complication involving an iatrogenic extended lesion of the tibial nerve in the popliteal fossa that occurred in the course of a crossectomy and exeresis of the lesser saphenous vein. The complicated microsurgical reconstruction of this complex nerve injury is described, and the causes and errors leading to it are analyzed.

Adult↗

PubMed2005

Cardiac magnetic resonance imaging: long term reproducibility of the late enhancement signal in patients with chronic coronary artery disease.

OBJECTIVE: To determine long term reproducibility of the late enhancement (LE) signal in contrast enhanced magnetic resonance imaging (MRI) and potential changes of the signal after revascularisation. METHODS: 33 patients (29 men, mean (SD) 61 (11) years) with coronary artery disease (CAD) and left ventricular dysfunction (ejection fraction 30 (7)%) underwent two contrast enhanced MRI procedures within 9 (3) months. Fifteen patients (group A: 14 men, 59 (12) years) had no interventions between the two studies. Eighteen patients underwent revascularisation after MRI 1 (group B: 15 men, 62 (9) years). Changes in the LE signal between the first and second MRIs were investigated in both groups as well as intraobserver and interobserver variabilities for delineation of the signal. RESULTS: The LE signal was highly reproducible in groups A and B for segmental analysis (concordance 86% v 82%, respectively; kappa = 0.70 v 0.67) and summed scores (group A: r = 0.97, p < 0.001; group B: r = 0.93, p < 0.001). The LE signal was quantified as 27 (27) cm3 in group A versus 30 (16) cm3 in group B in the first MRI and 26 (25) cm3 versus 30 (15) cm3, respectively, for the second MRI (both not significant). Moreover, low intraobserver and interobserver variabilities were observed in segmental analysis (kappa = 0.86 and 0.74, respectively, for group A, and kappa = 0.87 and 0.82, respectively, for group B). CONCLUSION: In patients with chronic CAD, the LE signal in contrast enhanced MRI is very stable over an extended time period. These results further characterise contrast enhanced MRI as a useful tool for myocardial viability assessment. Low intraobserver and interobserver variabilities promise robustness of the method for clinical application.

Aged↗

PubMed2003

Defects on the dorsum of the hand--the posterior interosseous flap and its alternatives.

There are conditions that preclude the use of the posterior interosseous flap for reconstruction of the dorsum of the hand. Based on a series of 34 cases, these conditions are outlined and alternative solutions discussed. The posterior interosseous flap was employed for closure in 30 cases. In four cases different methods were used due to severe trauma to the wrist and distal forearm with potential impairment of the pedicle, a complex defect requiring a composite flap and an anatomical variation. Thin free flaps were employed alternatively. All flaps survived but there was marginal flap necrosis in two posterior interosseous flaps. The posterior interosseous flap proved its usefulness and reliability in reconstruction of the hand in this series. In four cases, free lateral arm and temporoparietal fascial flaps were employed. Flaps based on the main vessels of the forearm were not used due to their significant donor site morbidity.

Adolescent↗

PubMed2002

Thoracic wall reconstruction using both portions of the latissimus dorsi previously divided in the course of posterolateral thoracotomy.

OBJECTIVE: Besides other factors, the choice of reconstructive method for full thickness thoracic wall defects depends on the morbidity of preceding surgical procedures. The pedicled latissimus dorsi flap is a reliable and safe option for reconstruction of the thorax. A posterolateral thoracotomy, however, results in division of the muscle. Both parts of the muscle can be employed to close full thickness defects of the chest wall. The proximal part can be pedicled on the thoracodorsal vessels or the serratus branch; the distal part can be pedicled on paravertebral or intercostal perforators. This retrospective study was undertaken to evaluate the reconstructive potential of both parts of the latissimus dorsi in thoracic wall reconstruction after posterolateral thoracotomy. METHODS: Between 1987 and 1999, 36 consecutive patients underwent reconstruction of full-thickness thoracic wall defects with latissimus dorsi-flaps after posterolateral thoracotomies. The defects resulted from infection and open window thoracostomy (n=31), trauma (n=3) and resection of tumours (n=2). The patients' average age was 57 years (range 22-76 years). Twenty-five patients were male, 11 were female. In 31 cases the split latissimus dorsi alone was employed; in five cases additional flaps had to be used due to the size of the defects, additional intrathoracic problems or neighbouring defects. RESULTS: In 34 cases defect closure could be achieved without major complications. Empyema recurred in the pleural cavity in one case and one patient died of septicaemia. The 15 patients who had required a respirator in the preoperative phase could be extubated 4.8 days (average) after thoracic wall reconstruction. Postoperative hospital stay averaged 16 days. CONCLUSIONS: Different methods are available for reconstruction of full thickness defects of the thoracic wall. After posterolateral thoracotomy in the surgical treatment of empyema, oncologic surgery and traumatology, the latissimus dorsi muscle still retains some reconstructive potential. Advantages are low additional donor site morbidity and anatomical reliability. As it is located near the site of the defect, there is no need for additional surgical sites or intraoperative repositioning. In our service, the split latissimus dorsi muscle flap has proven to be a valuable and reliable option in thoracic wall reconstruction.

Adult↗

PubMed2002

Cardiac surgery with deep hypothermic circulatory arrest produces less systemic inflammatory response than low-flow cardiopulmonary bypass in newborns.

OBJECTIVE: We sought to compare low-flow cardiopulmonary bypass with deep hypothermic circulatory arrest in respect to the influence on the systemic inflammatory response. METHODS: Twenty-three infants weighing less than 10 kg and scheduled for repair of congenital malformations were enrolled in a randomized, controlled study. Eleven patients underwent cardiac surgery with deep hypothermic circulatory arrest (the DHCA group). Low-flow cardiopulmonary bypass was used in another 12 patients (the LF group). Interleukin 6 and 8 and anaphylatoxin C3a levels were measured 6 times perioperatively. Also, perioperative weight gain and a radiologic soft-tissue index were compared. RESULTS: All patients had an uneventful clinical course. Duration of deep hypothermic circulatory arrest was 40 +/- 4 minutes; the bypass time was significantly shorter in the DHCA group (85 +/- 8 vs 130 +/- 19 minutes). However, the duration of the operation was similar in both groups (245 +/- 30 vs 246 +/- 30 minutes). During cardiopulmonary bypass (rewarming), the concentration of C3a (3751 +/- 388 vs 5761 +/- 1688 ng/mL, mean +/- SEM) was significantly lower in the DHCA group than in the LF group. The interleukin 8 level was significantly lower, and the interleukin 6 level had a tendency to be lower in the DHCA group compared with levels in the LF group. There was less weight gain on the first postoperative day in the DHCA group (65 +/- 61 vs 408 +/- 118 g). The soft-tissue index suggested reduced edema formation in the DHCA group. CONCLUSION: Deep hypothermic circulatory arrest produces less systemic inflammatory response than low-flow cardiopulmonary bypass. In addition, there is an indication of less fluid accumulation postoperatively.

Blood Pressure↗

PubMed2002

Hand surgery and the internet: results of a worldwide survey.

The opportunities offered by the Internet are employed increasingly in medicine. To obtain data on the extent to which the Internet is used by hand surgeons, survey forms were sent to 1043 participants of the Congress of the IFSSH in Vancouver in 1998. Ninety-four per cent of the respondents use the Internet. Most of the participants use the World Wide Web for literature searches, information on events and to read scientific articles. E-mail is used for general and scientific communication with colleagues and also for transmission of patient-related data. Perceived apprehensions include secure transmission of sensitive data, slow data transmission, and the lack of structure and of an authority to control the contents of the Internet. Virtual congresses and a newsgroup on hand surgery seem to be worthwhile future goals. Some problems pointed out in this survey have already been solved, at least partially, and possible solutions for the rest are discussed.

Attitude to Computers↗

PubMed2001

Nyquist method for Wigner-Poisson quantum plasmas.

By means of the Nyquist method, we investigate the linear stability of electrostatic waves in homogeneous equilibria of quantum plasmas described by the Wigner-Poisson system. We show that, unlike the classical Vlasov-Poisson system, the Wigner-Poisson case does not necessarily possess a Penrose functional determining its linear stability properties. The Nyquist method is then applied to a two-stream distribution, for which we obtain an exact, necessary and sufficient condition for linear stability, as well as to a bump-in-tail equilibrium.

Journal Article↗

PubMed2001

Ischemically compromised myocardium displays different time-courses of functional recovery: correlation with morphological alterations?

OBJECTIVE: It has been demonstrated that positron emission tomography (PET) predicts the functional recovery of viable but ischemically compromised myocardium. Reversible contractile dysfunction after revascularization has been reported for 'hibernating myocardium' and stunned myocardium, however, there are little data concerning the time-course and the extent of improvement of the two different pathophysiological conditions. METHODS: Twenty-nine patients with advanced coronary artery disease and severely reduced left ventricular function (EF 18--35%) who were referred for isolated coronary artery bypass grafting underwent preoperative PET viability assessment and were functionally assessed by two-dimensional echocardiography preoperatively at 11 days, 14 weeks, and more than 12 months after surgical revascularization. Intraoperative biopsies were taken from dysfunctional areas defined by PET as segments of normal perfusion and normal metabolism (stunned myocardium) and from areas with a 'mismatch' between perfusion and metabolism (hibernating myocardium). The degree of morphological alterations was evaluated by electron microscopy. RESULTS: In 70% of the 240 dysfunctional segments, 'stunned myocardium' was present whereas 'hibernating myocardium' could be detected in only 24% (P < 0.01). Hibernating myocardium was associated with more severe preoperative wall motion abnormalities and incomplete postoperative recovery. After 1 year, 31% of 'stunned' segments vs. only 18% of 'hibernating' segments showed complete functional restoration (P < 0.05). This incomplete improvement was associated with more severe morphological alterations including depletion of sarcomeres, accumulation of glycogen, loss of sarcoplasmatic reticulum, and cellular sequestration. CONCLUSIONS: These data indicate that in patients with severe ischemic left ventricular dysfunction 'stunned myocardium' is more prevalent than 'hibernation'. Functional normalization is more frequent in 'stunned' segments, whereas areas of 'hibernation' showed more severe tissue injury and protracted recovery. Different degrees of myocardial injury coexist in most patients, which determines the time-course and the extent of improvement after revascularization.

Aged↗

PubMed2001

Results of biventricular repair of congenital cardiac malformations: definitive corrective surgery?

OBJECTIVES: Congenital cardiac malformations are usually corrected in the neonatal period or in early infancy. Corrective surgery may not always be definitive, especially in complex malformations. Long-term morbidity is influenced by reoperations and their risk. METHODS: This study analyzes our single-center experience over more than 20 years in a selected group of patients. Data were gathered, with special focus on causes and incidence for reoperations, respectively. RESULTS: Freedom from reoperation after 5, 10, and 15 years for each cardiac malformation was determined. The numbers describe in the following order patient years (y), number of patients (n), and freedom from reoperation at follow-up interval (%), respectively: atrial septal defect (15,864y, n=1198, 99+/-0/99+/-0/99+/-0), partial atrioventricular septal defect (2506y, n=234, 95+/-2/93+/-2/93+/-2), total anomalous pulmonary venous connection (742y, n=141, 93+/-1/91+/-0/91+/-0), complete atrioventricular septal defect (1715y, n=377, 81+/-3/76+/-3/72+/-4), tetralogy of Fallot <1 year (1503y, n=197, 94+/-4/85+/-1/74+/-3), transposition of great arteries (1459y, n=375, 88+/-2/83+/-4/73+/-7), interrupted aortic arch (IAA) (481y, n=98, 63+/-6/52+/-7/45+/-8), common arterial trunk (CAT) (599y, n=109, 64+/-6/24+/-6/11+/-5). CONCLUSIONS: In most congenital malformations surgical correction is definitive and the rate of reoperations is low. In complex anomalies, such as CAT and IAA, reoperations at long-term are more common. Analysis of such results and recognition of a sometimes inevitable operative morbidity helps to predict long-term outcome and influences the follow-up.

Age Factors↗

PubMed2001

Effect of C1-esterase-inhibitor on capillary leak and inflammatory response syndrome during arterial switch operations in neonates.

OBJECTIVE: To determine if prophylactic administration of C1-esterase-inhibitor would have a beneficial effect on postoperative weight gain and the inflammatory response in neonates undergoing cardiac surgery with cardiopulmonary bypass (CPB). DESIGN: Randomized, double-blinded study. SETTING: University-affiliated heart center. PARTICIPANTS: Twenty-four neonates with transposition of the great arteries. INTERVENTIONS: In group inhibitor (INH) patients (n = 12), 100 IU/kg of C1-esterase-inhibitor (Berinert) was given 30 minutes before CPB. In group placebo (P) patients (n = 12), placebo was administered instead. Interleukin (IL)-6, C3a anaphylatoxin, C1 activity, prekallikrein, Hageman factor, D-dimers, and clinical parameters were measured 6 times perioperatively. MEASUREMENTS AND MAIN RESULTS: All 24 patients had an uneventful clinical course. Mean arterial pressure and pulmonary oxygenation after CPB were superior in group INH patients. The weight gain on postoperative days 1 to 4 was significantly less in group INH patients compared with group P (55 +/- 59 g vs. 340 +/- 121 g, day 1). The concentration of IL-6 (76 +/- 17 pg/mL vs. 262 +/- 95 pg/mL during CPB) was significantly lower in group INH patients compared with group P patients. In contrast, no influence on C3a anaphylatoxin and coagulation factors was found. CONCLUSION: Prophylactic application of C1-esterase-inhibitor in neonates undergoing arterial switch operations produces less inflammatory response compared with placebo. This difference may have contributed to improved clinical parameters, including less weight gain postoperatively.

Capillary Leak Syndrome↗

PubMed2001

[Presentation of plastic surgery on the internet: experiences with the home page of a department].

Plastic surgeons are increasingly taking advantage of information opportunities offered by the internet. Between October 1998 and March 1999, 87 individuals returned by e-mail a feed-back form included in the homepage of the Division of Plastic Surgery, Department of Surgery, Karl-Franzens University School of Medicine, Graz, Austria. Most of the responses originated from Austria or other European countries; 10% were from overseas. The most frequent reason for visiting our homepage was to gain information on scientific activities in our department (43 visitors), followed by interest in plastic surgical procedures on the part of patients or referring physicians (35 visitors). Other reasons were interest in educational matters, positions, and general interest in plastic surgery. Our results show that physicians, medical students, and laypersons are increasingly inclined to seek information on plastic surgery via the internet. This in turn should encourage plastic surgery services to present themselves in the World Wide Web.

Austria↗

PubMed2001

Wing folding and the functional morphology of the wing base in Coleoptera.

The wing unfolding of Pachnoda marginata was examined using digital video (50 half-fps) and high speed video sequences (1000 fps), and the skeleto-muscular apparatus of the metathorax was described. Left and right hind wing are able to promote independently of each other. The hind wings do not unfold instantly when the elytra are lifted and may also reach the flight position (and beat) while still folded. Wing promotion is exhaustible and the time needed for unfolding varies considerably. These observations strongly suggest a muscular control. Wing unfolding is probably triggered by contraction of M. pleura alaris and a resulting proximad movement of the 3rd axillary sclerite, pulling the Media posterior backwards, while the Radius anterior is held by the basalar muscle as the antagonist. Our findings are in clear contrast to the earlier assumption that the hind wings of Coleoptera either unfold or fold due to intrinsic elasticity. The specific wing folding and unfolding mechanisms are autapomorphic character states of Coleoptera. They were maintained during evolution even though considerable variations of skeletal thoracic structures, musculature and venation occurred. (Additional material is available from the Zoology web page: http://www.urbanfischer.de/journals/zoology).

Journal Article↗

PubMed2001

Comparison of sestamibi, tetrofosmin, and Q12 retention in porcine myocardium.

UNLABELLED: Although there are several 99mTc perfusion tracers introduced for clinical use, there are no data available directly comparing these tracers with microsphere-determined flow. The aim of this study was to compare the myocardial retention of sestamibi, tetrofosmin, and Q12 in a porcine model. METHODS: We used a pig model with (n = 6) or without (n = 3) coronary occlusion. Each pig received a simultaneous injection of sestamibi and either tetrofosmin (group 1, n = 5) or Q12 (group 2, n = 4) labeled with either 99mTc or 95mTc (physical half-life, 61 d; photon energy, 204 keV) during pharmacologic vasodilation. Absolute myocardial retention of each tracer was calculated from the myocardial tracer activity and arterial input function. RESULTS: The plot of all three tracers versus flow achieved a plateau at a higher flow range. However, sestamibi showed a higher mean retention than either tetrofosmin (group 1, 0.27 +/- 0.11 vs. 0.16 +/- 0.06 mL/g/min, respectively; P < 0.01) or Q12 (group 2, 0.32 +/- 0.13 vs. 0.09 +/- 0.03 mL/g/min, respectively; P < 0.01). Furthermore, when a linear regression analysis was performed to assess the relationship between retention and microsphere-determined flow, sestamibi showed a greater increment in retention than did tetrofosmin or Q12. CONCLUSION: Although all of the tracers showed a nonlinear increase in retention as flow increased, sestamibi may display more favorable characteristics as a flow tracer in the porcine heart.

Animals↗

PubMed2000

Time course and extent of improvement of dysfunctioning myocardium in patients with coronary artery disease and severely depressed left ventricular function after revascularization: correlation with positron emission tomographic findings.

OBJECTIVES: This study was performed to evaluate the prevalence, time course of recovery and extent of improvement of segments with a positron emission tomographic (PET) flow-metabolism mismatch and match pattern, as well as of PET segments with normal perfusion but with impaired myocardial function. BACKGROUND: Previous studies have shown that scintigraphic techniques evaluating myocardial viability provide predictive information about the improvement of regional wall motion. However, there are little data concerning the time course and extent of improvement of segments according to preoperative scintigraphic patterns. METHODS: Twenty-nine patients with ischemic cardiomyopathy (ejection fraction 18% to 35%) underwent preoperative PET viability assessment and were functionally assessed by two-dimensional echocardiography preoperatively and at 11 days, 14 weeks and >12 months after coronary artery bypass graft surgery. RESULTS: In 168 (70%) of 240 dysfunctional segments, a "normal" scintigraphic pattern was present, whereas a "mismatch" pattern was observed in 24% (p<0.01). Mismatch areas were associated with more severe preoperative wall motion abnormalities and incomplete postoperative recovery. After one year, 31% of normal scintigraphic segments, compared with only 18% of mismatch segments, showed complete functional restoration (p<0.05). CONCLUSIONS: These data suggest that in patients with severe left ventricular dysfunction, a scintigraphic pattern of normal perfusion and normal metabolism is more prevalent than a flow-metabolism mismatch pattern. Functional recovery is more frequent in normal scintigraphic segments, whereas in mismatch segments, postoperative recovery remains incomplete even after one year.

Adult↗

PubMed2000

The function of resilin in beetle wings.

This account shows the distribution of elastic elements in hind wings in the scarabaeid Pachnoda marginata and coccinellid Coccinella septempunctata (both Coleoptera). Occurrence of resilin, a rubber-like protein, in some mobile joints together with data on wing unfolding and flight kinematics suggest that resilin in the beetle wing has multiple functions. First, the distribution pattern of resilin in the wing correlates with the particular folding pattern of the wing. Second, our data show that resilin occurs at the places where extra elasticity is needed, for example in wing folds, to prevent material damage during repeated folding and unfolding. Third, resilin provides the wing with elasticity in order to be deformable by aerodynamic forces. This may result in elastic energy storage in the wing.

Animals↗

PubMed2000

Primary repair of aortic arch obstruction with ventricular septal defect in preterm and low birth weight infants.

OBJECTIVE: Previous reports have suggested that prematurity and low birth weight are risk factors for definitive surgical intervention in congenital cardiac malformations. The following data review our experience with primary repair of the complex malformation of aortic arch obstruction with ventricular septal defect (VSD) in this patient population. METHODS: Since 1988, 21 consecutive preterm (</=36 weeks) and/or low birth weight (<3000 g) infants with interrupted aortic arch (IAA; n=10), or aortic coarctation (n=11) with VSD, underwent primary arch repair and VSD closure. The mean weight at operation was 2310 g (range, 1200-2900 g), including 12 patients at </=2500 g. The gestational age ranged from 30 to 41 weeks (mean, 36.4 weeks). Five patients with interrupted arch and two patients with coarctation also had severe subaortic stenosis, which was relieved by transatrial incision of the infundibular septum. RESULTS: The overall hospital mortality was 14% (3/21). Death was related to low cardiac output in association with severe subaortic stenosis (n=2) and sepsis (n=1). Late mortality occurred in three patients, two of which were non-cardiac. The mean follow-up was 33 months. Two patients had significant recurrent arch obstruction, which was successfully relieved by balloon angioplasty and surgical correction in one each. The survival at 30 days, and at 1 and 3 years was 86, 76 and 70%, respectively. CONCLUSIONS: Complete primary repair of aortic arch obstruction with VSD can be achieved with good results, even in the preterm and low birth weight infant. Therefore, early surgical repair of this congenital malformation is recommended.

Analysis of Variance↗